1
|
Hogenes AM, Slump CH, te Riet o. g. Scholten GA, Stommel MWJ, Fütterer JJ, Verdaasdonk RM. The Effect of Partial Electrical Insulation of the Tip and Active Needle Length of Monopolar Irreversible Electroporation Electrodes on the Electric Field Line Pattern and Temperature Gradient to Improve Treatment Control. Cancers (Basel) 2023; 15:4280. [PMID: 37686556 PMCID: PMC10486353 DOI: 10.3390/cancers15174280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/10/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Unintentional local temperature effects can occur during irreversible electroporation (IRE) treatment, especially near the electrodes, and most frequently near the tip. Partial electrical insulation of the IRE electrodes could possibly control these temperature effects. This study investigated and visualized the effect of partial electrical insulation applied to the IRE electrodes on the electric field line pattern and temperature gradient. Six designs of (partial) electrical insulation of the electrode tip and/or active needle length (ANL) of the original monopolar 19G IRE electrodes were investigated. A semolina in castor oil model was used to visualize the electric field line pattern in a high-voltage static electric field. An optical method to visualize a change in temperature gradient (color Schlieren) was used to image the temperature development in a polyacrylamide gel. Computational models were used to support the experimental findings. Around the electrode tip, the highest electric field line density and temperature gradient were present. The more insulation was applied to the electrodes, the higher the resistance. Tip and ANL insulation together reduced the active area of and around the electrodes, resulting in a visually enlarged area that showed a change in temperature gradient. Electrically insulating the electrode tip together with an adjustment in IRE parameter settings could potentially reduce the uncontrollable influence of the tip and may improve the predictability of the current pathway development.
Collapse
Affiliation(s)
- Annemiek M. Hogenes
- Department of Medical Imaging, Radboud University Medical Center, P.O. Box 9101 (766), 6500 HB Nijmegen, The Netherlands
| | - Cornelis H. Slump
- Department of Robotics and Mechatronics, University of Twente, 7522 NB Enschede, The Netherlands
| | | | - Martijn W. J. Stommel
- Department of Surgery, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Jurgen J. Fütterer
- Department of Medical Imaging, Radboud University Medical Center, P.O. Box 9101 (766), 6500 HB Nijmegen, The Netherlands
- Department of Robotics and Mechatronics, University of Twente, 7522 NB Enschede, The Netherlands
| | - Rudolf M. Verdaasdonk
- Department of Health Technology Implementation, TechMed Center, University of Twente, 7522 NB Enschede, The Netherlands
| |
Collapse
|
2
|
Schimberg AS, Heldens GTN, Klabbers TM, van Engen-Van Grunsven ACH, Verdaasdonk RM, Takes RP, Wellenstein DJ, van den Broek GB. Thermal Effects of CO 2, KTP, and Blue Lasers with a Flexible Fiber Delivery System on Vocal Folds. J Voice 2022:S0892-1997(22)00074-1. [PMID: 35418349 DOI: 10.1016/j.jvoice.2022.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the differences in thermal effects on vocal folds between four fiber-routed lasers. METHODS In this experimental laboratory study the thermal effects of an AcuPulse Duo CO2 (CO2 AP), UltraPulse Duo CO2 (CO2 UP), KTP, and Blue laser were analyzed using a Schlieren technique on a human tissue mimicking gel model. Power, laser duration, laser fiber distance to tissue and mode (continuous wave [CW] vs pulsed [P] modes) were evaluated in varying combinations in order to compare the effects of the tested lasers and to explore the individual effect on thermal expansion and incision depth of each setting. The model was validated by comparing the results from the Schlieren model with histology of ex vivo fresh human vocal folds after laser irradiation using a selection of the same laser settings, and calculating the intraclass correlation coefficient (ICC). RESULTS One thousand ninety-eight Schlieren experiments and 56 vocal cord experiments were conducted. In comparison with CW mode, less thermal expansion occurred in P mode in all lasers, while incisions were deeper in the CO2 and more superficial in the KTP and Blue lasers. The mean thermal expansion was found to be minimally smaller, whereas incision depth was pronouncedly smaller in the KTP and Blue compared to the CO2 lasers. Duration of laser irradiation was the most important factor of influence on thermal expansion and incision depth for all lasers in both CW and P modes. The ICC for consistency between the results of the Schlieren model and the vocal cord histology was classified from fair to excellent, except for the thermal expansion of the Blue laser, which was classified as poor. CONCLUSION This study demonstrates important differences in thermal effects between CO2, KTP, and Blue lasers which can be explained by the different physical characteristics of the P modes and divergence of the fiber delivery system. The Schlieren imaging model is a good predictor of the relative thermal effects in vocal fold tissue. Our results can be used as a guidance for ENT surgeons using fiber-routed lasers, in order to achieve effective treatment of vocal fold lesions and prevention of functional impairment of vocal folds.
Collapse
Affiliation(s)
- Anouk S Schimberg
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Gijs T N Heldens
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tim M Klabbers
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Rudolf M Verdaasdonk
- Department of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Robert P Takes
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - David J Wellenstein
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Guido B van den Broek
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
3
|
Schimberg AS, Klabbers TM, Wellenstein DJ, Heutink F, Honings J, van Engen-Van Grunsven I, Verdaasdonk RM, Takes RP, van den Broek GB. Optimizing Settings for Office-Based Endoscopic CO 2 Laser Surgery Using an Experimental Vocal Cord Model. Laryngoscope 2020; 130:E680-E685. [PMID: 32022931 PMCID: PMC7687150 DOI: 10.1002/lary.28518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/10/2019] [Accepted: 12/30/2019] [Indexed: 01/21/2023]
Abstract
OBJECTIVES/HYPOTHESIS To provide insight in the thermal effects of individual laser settings in target tissues to optimize flexible endoscopic CO2 laser surgery treatment. STUDY DESIGN Experimental laboratory study. METHODS Thermal effects of the CO2 laser using a fiber delivery system were visualized using the color Schlieren technique in combination with a polyacrylamide gel tissue model. Variable settings were used for emission mode, power, laser fiber distance, and laser duration, which were evaluated in every possible combination. Collateral thermal expansion and incision depth were measured. To validate the model, the results were compared to histology after CO2 laser irradiation of ex vivo human vocal cords, and the intraclass correlation coefficient was calculated. Thermal damage and incision depth were measured by a blinded pathologist. RESULTS Of all parameters studied, duration of laser irradiation had the greatest effect on thermal expansion. Increased distance between laser tip and target tissue resulted in significantly reduced incision depth and increased thermal expansion. Pulsed emission modes led to increased incision depths. The intraclass correlation coefficient for consistency between the model setup and the ex vivo human vocal cords was classified as "fair." CONCLUSIONS By using high-intensity pulsed lasers at minimal distance to the target tissue, exposure times and subsequent damage to surrounding tissue can be reduced. If an evaporation technique is used, lower power in continuous wave at a larger distance to the target tissue will lead to superficial but broader thermal effects. The model setup used in this study is a valid model to investigate laser-induced thermal effects in vocal cord tissue. LEVEL OF EVIDENCE NA Laryngoscope, 130:E680-E685, 2020.
Collapse
Affiliation(s)
- Anouk S Schimberg
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tim M Klabbers
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - David J Wellenstein
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Floris Heutink
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jimmie Honings
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Rudolf M Verdaasdonk
- Department of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Robert P Takes
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Guido B van den Broek
- Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
4
|
Uitentuis SE, Heilmann MN, Verdaasdonk RM, Bae JM, Luiten RM, Wolkerstorfer A, Bekkenk MW. Ultraviolet photography in vitiligo: image quality, validity and reliability. J Eur Acad Dermatol Venereol 2020; 34:1590-1594. [PMID: 31994253 PMCID: PMC7496888 DOI: 10.1111/jdv.16226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 01/07/2020] [Indexed: 11/30/2022]
Abstract
Background For clinical care and research in vitiligo, photographs with the use of ultraviolet (UV) light or Wood's lamp are often made. Conventional cameras are insensitive to UV light. The use of a UV camera (UV photography) might improve image quality and ameliorate the assessment of target lesions in vitiligo. Objectives To determine image quality and the validity and reliability of UV photography for the assessment of vitiligo target lesions. Methods Images of patients with vitiligo were made with UV photography and a conventional camera, and lesions were drawn on graph paper and transparent sheets. Image quality was scored by vitiligo experts and medical interns. The intraclass correlation coefficients (ICCs) of the lesion size determined with UV photography combined with digital surface measurement and the other techniques were hypothesized to be above 0.6. The ICCs between UV images taken by the same physician and between two different physicians were calculated for determining inter‐ and intra‐reliability. Results In total, 31 lesions of 17 patients were included. Image quality was assessed as good or very good for 100% and 26% for UV photography and the conventional camera, respectively. ICCs of UV photography and the conventional camera, drawing the lesions on transparent sheets and graph paper, were 0.984, 0.988 and 0.983, respectively, confirming our hypotheses. The ICCs of the intra‐rater and inter‐rater were 0.999 and 0.998, respectively. Conclusions The results of this study indicate that the use of UV photography for the assessment of vitiligo lesions improves image quality and is valid and reliable.
Collapse
Affiliation(s)
- S E Uitentuis
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - M N Heilmann
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - R M Verdaasdonk
- Department of Biomedical Photonics & Imaging, University of Twente, Enschede, The Netherlands
| | - J M Bae
- Department of Dermatology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea
| | - R M Luiten
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - A Wolkerstorfer
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - M W Bekkenk
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
5
|
Nieboer MJ, Meesters AA, Almasian M, Georgiou G, de Rie MA, Verdaasdonk RM, Wolkerstorfer A. Enhanced topical cutaneous delivery of indocyanine green after various pretreatment regimens: comparison of fractional CO 2 laser, fractional Er:YAG laser, microneedling, and radiofrequency. Lasers Med Sci 2020; 35:1357-1365. [PMID: 31984457 PMCID: PMC7351854 DOI: 10.1007/s10103-020-02950-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/02/2020] [Indexed: 11/24/2022]
Abstract
Different devices have been used to enhance topical drug delivery. Aim of this study was to compare the efficacy of different skin pretreatment regimens in topical drug delivery. In six ex vivo human abdominal skin samples, test regions were pretreated with fractional CO2 and Er:YAG laser (both 70 and 300 μm ablation depth, density of 5%), microneedling (500 μm needle length), fractional radiofrequency (ablation depth of ± 80–90 μm), and no pretreatment. The fluorescent agent indocyanine green (ICG) was applied. After 3 h, fluorescence intensity was measured at several depths using fluorescence photography. Significantly higher surface fluorescence intensities were found for pretreatment with fractional Er:YAG and CO2 laser and for microneedling vs. no pretreatment (p < 0.05), but not for radiofrequency vs. no pretreatment (p = 0.173). Fluorescence intensity was highest for the Er:YAG laser with 300 μm ablation depth (mean 38.89 arbitrary units; AU), followed by microneedling (33.02 AU) and CO2 laser with 300 μm ablation depth (26.25 AU). Pretreatment with both lasers with 300 μm ablation depth gave higher fluorescence intensity than with 70 μm ablation depth (Er:YAG laser, 21.65; CO2 laser, 18.50 AU). Mean fluorescence intensity for radiofrequency was 15.27 AU. Results were comparable at 200 and 400 μm depth in the skin. Pretreatment of the skin with fractional CO2 laser, fractional Er:YAG laser, and microneedling is effective for topical ICG delivery, while fractional radiofrequency is not. Deeper laser ablation results in improved ICG delivery. These findings may be relevant for the delivery of other drugs with comparable molecular properties.
Collapse
Affiliation(s)
- Marilin J Nieboer
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, NL-1105, Amsterdam, AZ, Netherlands
| | - Arne A Meesters
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, NL-1105, Amsterdam, AZ, Netherlands.
| | - Mitra Almasian
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Meibergdreef 9, NL-1105, Amsterdam, AZ, Netherlands
| | - Giota Georgiou
- TechMed Center, BioMedical Photonics and Imaging group, University of Twente, Drienerlolaan 5, 7522, Enschede, NB, Netherlands
| | - Menno A de Rie
- Department of Dermatology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, NL-1105, Amsterdam, AZ, Netherlands.,Department of Dermatology, VU Medical Center, De Boelelaan 1117, VU University, NL-1081, Amsterdam, HV, Netherlands
| | - Rudolf M Verdaasdonk
- TechMed Center, BioMedical Photonics and Imaging group, University of Twente, Drienerlolaan 5, 7522, Enschede, NB, Netherlands
| | - Albert Wolkerstorfer
- Netherlands Institute for Pigment Disorders, Department of Dermatology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, NL-1105, Amsterdam, AZ, Netherlands
| |
Collapse
|
6
|
Bruins AA, Geboers DGPJ, Bauer JR, Klaessens JHGM, Verdaasdonk RM, Boer C. The vascular occlusion test using multispectral imaging: a validation study : The VASOIMAGE study. J Clin Monit Comput 2020; 35:113-121. [PMID: 31902095 DOI: 10.1007/s10877-019-00448-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 12/14/2019] [Indexed: 12/11/2022]
Abstract
Multispectral imaging (MSI) is a new, non-invasive method to continuously measure oxygenation and microcirculatory perfusion, but has limitedly been validated in healthy volunteers. The present study aimed to validate the potential of multispectral imaging in the detection of microcirculatory perfusion disturbances during a vascular occlusion test (VOT). Two consecutive VOT's were performed on healthy volunteers and tissue oxygenation was measured with MSI and near-infrared spectroscopy (NIRS). Correlations between the rate of desaturation, recovery and the hyperemic area under the curve (AUC) measured by MSI and NIRS were calculated. Fifty-eight volunteers were included. The MSI oxygenation curves showed identifiable components of the VOT, including a desaturation and recovery slope and hyperemic area under the curve, similar to those measured with NIRS. The correlation between the rate of desaturation measured by MSI and NIRS was moderate: r = 0.42 (p = 0.001) for the first and r = 0.41 (p = 0.002) for the second test. Our results suggest that non-contact multispectral imaging is able to measure changes in regional oxygenation and deoxygenation during a vascular occlusion test in healthy volunteers. When compared to measurements with NIRS, correlation of results was moderate to weak, most likely reflecting differences in physiology of the regions of interest and measurement technique.
Collapse
Affiliation(s)
- Arnoud A Bruins
- Departments of Anesthesiology, Amsterdam UMC, VU University, location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. .,Amsterdam Cardiovascular Sciences, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Diederik G P J Geboers
- Departments of Anesthesiology, Amsterdam UMC, VU University, location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Jacob R Bauer
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), Gjøvik, Norway
| | - John H G M Klaessens
- Department of Clinical Physics, Medical Center Leeuwarden, Leeuwarden, The Netherlands
| | - Rudolf M Verdaasdonk
- TechMed Center, BioMedical Photonics & Medical Imaging, University of Twente, Enschede, The Netherlands
| | - Christa Boer
- Departments of Anesthesiology, Amsterdam UMC, VU University, location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| |
Collapse
|
7
|
Bauer JR, Thomas JB, Hardeberg JY, Verdaasdonk RM. An Evaluation Framework for Spectral Filter Array Cameras to Optimize Skin Diagnosis. Sensors (Basel) 2019; 19:E4805. [PMID: 31694239 PMCID: PMC6864639 DOI: 10.3390/s19214805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 01/02/2023]
Abstract
Comparing and selecting an adequate spectral filter array (SFA) camera is application-specific and usually requires extensive prior measurements. An evaluation framework for SFA cameras is proposed and three cameras are tested in the context of skin analysis. The proposed framework does not require application-specific measurements and spectral sensitivities together with the number of bands are the main focus. An optical model of skin is used to generate a specialized training set to improve spectral reconstruction. The quantitative comparison of the cameras is based on reconstruction of measured skin spectra, colorimetric accuracy, and oxygenation level estimation differences. Specific spectral sensitivity shapes influence the results directly and a 9-channel camera performed best regarding the spectral reconstruction metrics. Sensitivities at key wavelengths influence the performance of oxygenation level estimation the strongest. The proposed framework allows to compare spectral filter array cameras and can guide their application-specific development.
Collapse
Affiliation(s)
- Jacob Renzo Bauer
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), 2815 Gjøvik, Norway; (J.-B.T.); (J.Y.H.)
| | - Jean-Baptiste Thomas
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), 2815 Gjøvik, Norway; (J.-B.T.); (J.Y.H.)
| | - Jon Yngve Hardeberg
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), 2815 Gjøvik, Norway; (J.-B.T.); (J.Y.H.)
| | - Rudolf M. Verdaasdonk
- Biomedical Photonics and Imaging group, Faculty of Science and Technology, University of Twente, 7522NB Enschede, The Netherlands;
| |
Collapse
|
8
|
Tebbens M, Nota NM, Liberton NPTJ, Meijer BA, Kreukels BPC, Forouzanfar T, Verdaasdonk RM, den Heijer M. Gender-Affirming Hormone Treatment Induces Facial Feminization in Transwomen and Masculinization in Transmen: Quantification by 3D Scanning and Patient-Reported Outcome Measures. J Sex Med 2019; 16:746-754. [PMID: 30926514 DOI: 10.1016/j.jsxm.2019.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Hormone treatment induces feminization of the body in transwomen and masculinization in transmen. However, the effect of hormone treatment on facial characteristics is still unknown. AIM We aimed to study whether hormone treatment induces facial feminization and masculinization and how this potential change affects satisfaction and self-esteem. METHODS In this single-center cohort study, we included 27 transwomen and 15 transmen who received standardized hormone treatment in the Center of Expertise on Gender Dysphoria, VU University Medical Center Amsterdam. Facial 3-dimensional images were obtained at baseline and at 3 and 12 months. At each image, 22 facial landmarks were placed. Furthermore, the FACE-Q Satisfaction with Facial Appearance Overall and the Rosenberg self-esteem scale were obtained at the same measurement points. MAIN OUTCOME MEASURES The main outcome measures included the relative local shift of skin in millimeters in the 22 landmarks in the transverse (x-axis), coronal (y-axis), and sagittal (z-axis) anatomic axes, the color maps, and the outcomes of the questionnaires. RESULTS After 12 months, cheek tissue in transwomen increased, with 0.50 mm (95% CI 0.04-0.96) in the x-axis and 1.08 mm (95% CI 0.31-1.85) in the z-axis. Tissue in the jaws decreased with -0.60 mm (95% CI -1.28-0.08) in the x-axis and -0.18 mm (95% CI -0.03-0.33) in the y-axis. Cheek tissue in transmen decreased with -0.45 mm (95% CI -1.00-0.11) in the x-axis and -0.84 mm (95% CI -1.92-0.25) in the z-axis. These changes already started after 3 months. An increase in satisfaction with the facial appearance was found in both transwomen and transmen. There were no changes in reported self-esteem. CLINICAL IMPLICATION These results could lead to more realistic expectations of facial changes. Furthermore, our results suggest that the face continues to change for at least a year, which could suggest that performing facial feminization surgery after 1 year of hormone treatment might be too early. STRENGTH & LIMITATIONS This study is the first that provides insight into the facial changes in transgender individuals receiving hormone treatment, and it introduces an objective method to examine (small) facial changes. Our study is limited by the poor reliability of the landmarks, the difficulty of facial fixation, and the lack of gender-specific questions in the questionnaires. CONCLUSIONS Hormone treatment in transwomen induces an increase in cheek tissue and a decrease in jaw tissue. In transmen a tendency of decrease in cheek tissue and an increase in jaw tissue was found. These changes are in the direction of the desired gender. Tebbens M, Nota NM, Liberton NPTJ, et al. Gender-Affirming Hormone Treatment Induces Facial Feminization in Transwomen and Masculinization in Transmen: Quantification by 3D Scanning and Patient-Reported Outcome Measures. J Sex Med 2019;16:746-754.
Collapse
Affiliation(s)
- Marieke Tebbens
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Internal Medicine, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - Nienke M Nota
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Internal Medicine, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - Niels P T J Liberton
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physics and Medical Technology, 3D InnovationLab, Amsterdam, the Netherlands
| | - Brigitte A Meijer
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Oral and Maxillofacial Surgery, Amsterdam, the Netherlands
| | - Baudewijntje P C Kreukels
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Psychology and Center of Expertise on Gender Dysphoria, Amsterdam, the Netherlands
| | - Tim Forouzanfar
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Oral and Maxillofacial Surgery, Amsterdam, the Netherlands
| | - Rudolf M Verdaasdonk
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physics and Medical Technology, 3D InnovationLab, Amsterdam, the Netherlands
| | - Martin den Heijer
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Internal Medicine, Amsterdam Movement Sciences, Amsterdam, the Netherlands.
| |
Collapse
|
9
|
Meesters AA, Nieboer MJ, Almasian M, Georgiou G, de Rie MA, Verdaasdonk RM, Wolkerstorfer A. Drug penetration enhancement techniques in ablative fractional laser assisted cutaneous delivery of indocyanine green. Lasers Surg Med 2019; 51:709-719. [PMID: 30908718 PMCID: PMC6767780 DOI: 10.1002/lsm.23088] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2019] [Indexed: 12/25/2022]
Abstract
Background and Objectives Topical drug delivery can be increased by pretreatment of the skin with ablative fractional laser (AFXL). Several physical penetration enhancement techniques have been investigated to further improve AFXL‐assisted drug delivery. This study investigated the influence of three of these techniques, namely massage, acoustic pressure wave treatment, and pressure vacuum alterations (PVP) on the distribution of the fluorescent drug indocyanine green (ICG) at different depths in the skin after topical application on AFXL pretreated skin. Materials and Methods In ex vivo human skin, test regions were pretreated with AFXL (10,600 nm, channel depth 300 μm, channel width 120 μm, density 15%). Subsequently, ICG was applied, followed by massage, acoustic pressure wave treatment or PVP. ICG fluorescence intensity (FI) was assessed after 1, 3, and 24 hours at several depths using fluorescence photography. Results FI was higher when using enhancement techniques compared to control (AFXL‐only) up to 3 hours application time (P < 0.05). After 3 hours, mean surface FI was highest after acoustic pressure wave treatment (61.5 arbitrary units; AU), followed by massage (57.5AU) and PVP (46.9AU), respectively (for comparison: AFXL‐only 31.6AU, no pretreatment 14.9AU). Comparable or higher FI was achieved already after 1 hour with enhancement techniques compared to 3–24 hours application time without. After 24 hours, no significant differences between enhancement techniques and AFXL‐only were observed (P = 0.31). Conclusion Penetration enhancement techniques, especially acoustic pressure wave treatment and massage, result in improved drug accumulation in AFXL‐pretreated skin and reduce the application time needed. Lasers Surg. Med. © 2019 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Arne A Meesters
- Department of Dermatology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, NL-1105 AZ, Amsterdam, The Netherlands
| | - Marilin J Nieboer
- Department of Dermatology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, NL-1105 AZ, Amsterdam, The Netherlands
| | - Mitra Almasian
- Department of Dermatology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, NL-1105 AZ, Amsterdam, The Netherlands
| | - Giota Georgiou
- Department of Physics and Medical Technology, Amsterdam UMC, VU University, De Boelelaan 1117, NL-1081 HV, Amsterdam, The Netherlands
| | - Menno A de Rie
- Department of Dermatology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, NL-1105 AZ, Amsterdam, The Netherlands.,Department of Dermatology, Amsterdam UMC, VU University, De Boelelaan 1117, NL-1081 HV, Amsterdam, The Netherlands
| | - Rudolf M Verdaasdonk
- Department of Science and Technology, University of Twente, NL-7522 NB, Enschede, The Netherlands
| | - Albert Wolkerstorfer
- Department of Dermatology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, NL-1105 AZ, Amsterdam, The Netherlands
| |
Collapse
|
10
|
de Boorder T, Brouwers HB, Noordmans HJ, Woerdeman PA, Han KS, Verdaasdonk RM. Thulium laser-assisted endoscopic third ventriculostomy: Determining safe laser settings using in vitro model and 2 year follow-up results in 106 patients. Lasers Surg Med 2017; 50:629-635. [PMID: 29214660 DOI: 10.1002/lsm.22779] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2017] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Endoscopic third ventriculostomy is used to treat hydrocephalus. Different laser wavelengths have been proposed for laser-assisted endoscopic third ventriculostomies over the last decades. The aim of this study was to evaluate Thulium laser endoscopic third ventriculostomy heat penetration in the surrounding environment of the floor of the third ventricle in an in vitro setting with visualization of thermal distribution. Subsequently 106 Thulium laser endoscopic third ventriculostomy procedures were retrospectively analyzed to demonstrate safety. METHODS The in vitro visualization was based on the color Schlieren method. The heat penetration was measured beneath a tissue phantom of the floor of the third ventricle with a fiber of 365 μm in diameter at different energy settings; 1.0W (956 J/cm2 ), 2.0W (1,912 J/cm2 ), 4.0W (3,824 J/cm2 ), and 7.0W (6,692 J/cm2 ), with a pulse duration of 1.0 second. All experiments were repeated five times. In addition, 106 Thulium laser endoscopic third ventriculostomy procedures between 2005 and 2015 were retrospectively analysed for etiology, sex, complications, and laser parameters. RESULTS In the energy settings from 1.0 to 4.0 W, heat penetration depth beneath the phantom of the third ventricle did not exceed 1.5 mm. The heat penetration depth at 7 W, exceeded 6 mm. The clinical overall success rate was 80% at the 2-year follow-up study. Complications occurred in 5% of the procedures. In none of the 106 investigated clinical patients bleeding or damage to the basilar artery was encountered due to Thulium laser ablation. CONCLUSIONS The in vitro experiments show that under 4.0W the situation is considered safe, due to low penetration of heat, thus the chance of accidentally damaging critical structures like the basilar artery is very small. The clinical results show that the Thulium laser did not cause any bleeding of the basilar artery, and is a safe technique for laser endoscopic third ventriculostomy. Lasers Surg. Med. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Tjeerd de Boorder
- Department of Medical Technology and Clinical Physics, Utrecht, The Netherlands
| | - Hans B Brouwers
- Department of Neurosurgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Herke Jan Noordmans
- Department of Medical Technology and Clinical Physics, Utrecht, The Netherlands
| | - Peter A Woerdeman
- Department of Neurosurgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Kuo S Han
- Department of Neurosurgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Rudolf M Verdaasdonk
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
11
|
Bruins AA, Kistemaker KRJ, Boom A, Klaessens JHGM, Verdaasdonk RM, Boer C. Thermographic skin temperature measurement compared with cold sensation in predicting the efficacy and distribution of epidural anesthesia. J Clin Monit Comput 2017; 32:335-341. [PMID: 28508148 PMCID: PMC5838146 DOI: 10.1007/s10877-017-0026-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 04/28/2017] [Indexed: 11/25/2022]
Abstract
Due to the high rates of epidural failure (3-32%), novel techniques are required to objectively assess the successfulness of an epidural block. In this study we therefore investigated whether thermographic temperature measurements have a higher predictive value for a successful epidural block when compared to the cold sensation test as gold standard. Epidural anesthesia was induced in 61 patients undergoing elective abdominal, thoracic or orthopedic surgery. A thermographic picture was recorded at 5, 10 and 15 min following epidural anesthesia induction. After 15 min a cold sensation test was performed. Epidural anesthesia is associated with a decrease in skin temperature. Thermography predicts a successful epidural block with a sensitivity of 54% and a PPV of 92% and a specificity of 67% and a NPV of 17%. The cold sensation test shows a higher sensitivity and PPV than thermography (97 and 93%), but a lower specificity and NPV than thermography (25 and 50%). Thermographic temperature measurements can be used as an additional and objective method for the assessment of the effectiveness of an epidural block next to the cold sensation test, but have a low sensitivity and negative predictive value. The local decrease in temperature as observed in our study during epidural anesthesia is mainly attributed to a core-to-peripheral redistribution of body heat and vasodilation.
Collapse
Affiliation(s)
- Arnoud A Bruins
- Department of Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Kay R J Kistemaker
- Department of Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Annemieke Boom
- Spaarne Gasthuis, Spaarnepoort 1, 2134 TM, Hoofddorp, The Netherlands
| | - John H G M Klaessens
- Department of Physics and Medical Technology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Rudolf M Verdaasdonk
- Department of Physics and Medical Technology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Christa Boer
- Department of Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| |
Collapse
|
12
|
Jaspers MEH, Maltha I, Klaessens JHGM, de Vet HCW, Verdaasdonk RM, van Zuijlen PPM. Insights into the use of thermography to assess burn wound healing potential: a reliable and valid technique when compared to laser Doppler imaging. J Biomed Opt 2016; 21:96006. [PMID: 27623232 DOI: 10.1117/1.jbo.21.9.096006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/24/2016] [Indexed: 06/06/2023]
Abstract
Adequate assessment of burn wounds is crucial in the management of burn patients. Thermography, as a noninvasive measurement tool, can be utilized to detect the remaining perfusion over large burn wound areas by measuring temperature, thereby reflecting the healing potential (HP) (i.e., number of days that burns require to heal). The objective of this study was to evaluate the clinimetric properties (i.e., reliability and validity) of thermography for measuring burn wound HP. To evaluate reliability, two independent observers performed a thermography measurement of 50 burns. The intraclass correlation coefficient (ICC), the standard error of measurement (SEM), and the limits of agreement (LoA) were calculated. To assess validity, temperature differences between burned and nonburned skin (?T) were compared to the HP found by laser Doppler imaging (serving as the reference standard). By applying a visual method, one ?T cutoff point was identified to differentiate between burns requiring conservative versus surgical treatment. The ICC was 0.99, expressing an excellent correlation between two measurements. The SEM was calculated at 0.22°C, the LoA at ?0.58°C and 0.64°C. The ?T cutoff point was ?0.07°C (sensitivity 80%; specificity 80%). These results show that thermography is a reliable and valid technique in the assessment of burn wound HP.
Collapse
Affiliation(s)
- Mariëlle E H Jaspers
- Burn Center, Red Cross Hospital, P.O. Box 1074, 1940 EB Beverwijk, The NetherlandsbAssociation of Dutch Burn Centers, P.O. Box 1015, 1940 EA Beverwijk, The NetherlandscRed Cross Hospital, Department of Plastic, Reconstructive and Hand Surgery, P.O. Box 1074, 1940 EB Beverwijk, The NetherlandsdVU Medical Center, Department of Plastic, Reconstructive and Hand Surgery, P.O. Box 7057, 1007 MB Amsterdam, The NetherlandseResearch Institute MOVE VU University Medical Center of Amsterdam, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Ilse Maltha
- Burn Center, Red Cross Hospital, P.O. Box 1074, 1940 EB Beverwijk, The Netherlands
| | - John H G M Klaessens
- VU University Medical Center, Department of Physics and Medical Technology, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Henrica C W de Vet
- VU University Medical Center, Department of Epidemiology and Biostatistics, P.O. Box 7057, 1007 MB Amsterdam, The NetherlandshVU University Medical Center, EMGO Institute for Health and Care Research, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Rudolf M Verdaasdonk
- VU University Medical Center, Department of Physics and Medical Technology, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Paul P M van Zuijlen
- Burn Center, Red Cross Hospital, P.O. Box 1074, 1940 EB Beverwijk, The NetherlandsbAssociation of Dutch Burn Centers, P.O. Box 1015, 1940 EA Beverwijk, The NetherlandscRed Cross Hospital, Department of Plastic, Reconstructive and Hand Surgery, P.O. Box 1074, 1940 EB Beverwijk, The NetherlandsdVU Medical Center, Department of Plastic, Reconstructive and Hand Surgery, P.O. Box 7057, 1007 MB Amsterdam, The NetherlandseResearch Institute MOVE VU University Medical Center of Amsterdam, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| |
Collapse
|
13
|
de Sitter A, Verdaasdonk RM, Faes TJC. Do mathematical model studies settle the controversy on the origin of cardiac synchronous trans-thoracic electrical impedance variations? A systematic review. Physiol Meas 2016; 37:R88-R108. [PMID: 27531544 DOI: 10.1088/0967-3334/37/9/r88] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Impedance cardiography (ICG) is a method to evaluate cardiac-stroke volume and cardiac-output by measuring the cardiac-synchronous changes in the dynamic trans-thoracic electrical impedance (ΔZ). Clinical evaluations on the accuracy of ICG showed varying results. Consequently, the classic assumption in ICG-the aorta as a main source of ΔZ-is questioned and subsequently investigated in simulation studies using mathematical models of the electrical resistivity of the human body. The aim is to review the consensus in mathematical modelling studies that investigate the origin of the ΔZ as measured in ICG. In a systematic literature search, studies were identified and surveyed with reference to characteristics, such as included organs and their resistivity and geometries, electrode positions and calculation of ΔZ, to review the consensus between mathematical modelling studies that investigate the origin of the ΔZ as measured in ICG. Thirteen papers showed considerable variation in the model's characteristics with varying or contradicting outcomes for the ΔZ 's origin. For instance, 11 studies excluded perfused muscle tissue, implying implicitly their insignificance, while 3 other studies included muscle tissue and indicated it as the most important origin of ΔZ. In conclusion, the reviewed papers show a lack of consensus with respect to both the modelled characteristics as well as the model outcomes and, as a result, these studies failed to settle the controversy on ΔZ 's origin. Recommendations have been added to improve future mathematical model studies.
Collapse
Affiliation(s)
- A de Sitter
- VU University, Faculty of Science, Amsterdam, The Netherlands. Department of Physics and Medical Technology, VU University Medical Centre, Amsterdam, The Netherlands
| | | | | |
Collapse
|
14
|
Abstract
Introduction: Non-invasive methods for imaging varicose veins allow quantification and evaluation of venous diseases. This paper will describe a technique to visualize superficial (subdermal) varicose veins using digital infrared imaging and analysis with special software. Method: After image acquisition, the pictures were analysed with special software that segmented the varicose veins and calculated the surface area (per gridblock) occupied by varicose veins. By comparing the surfaces occupied by varices before and after a specific treatment, one can establish which treatment method performs the best. Aim for the future: Validation of this technique and quantification of the effects of treatment modalities for superficial (subdermal) varicose veins. We also investigate the use of this technique for the other clinical CEAP stages and the potential resemblance with duplex scanning.
Collapse
Affiliation(s)
- R de Zeeuw
- Department of Phlebology and Vascular Surgery, Vascular Center, Sint Franciscus Gasthuis, Rotterdam, The Netherlands
| | - H J Noordmans
- Medical Physics, University Hospital, Utrecht, The Netherlands
| | - R M Verdaasdonk
- Medical Physics, University Hospital, Utrecht, The Netherlands
| | - C H A Wittens
- Department of Phlebology and Vascular Surgery, Vascular Center, Sint Franciscus Gasthuis, Rotterdam, The Netherlands
| |
Collapse
|
15
|
Scheffer HJ, Vogel JA, van den Bos W, Neal RE, van Lienden KP, Besselink MGH, van Gemert MJC, van der Geld CWM, Meijerink MR, Klaessens JH, Verdaasdonk RM. The Influence of a Metal Stent on the Distribution of Thermal Energy during Irreversible Electroporation. PLoS One 2016; 11:e0148457. [PMID: 26844550 PMCID: PMC4742246 DOI: 10.1371/journal.pone.0148457] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/18/2016] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Irreversible electroporation (IRE) uses short duration, high-voltage electrical pulses to induce cell death via nanoscale defects resulting from altered transmembrane potential. The technique is gaining interest for ablations in unresectable pancreatic and hepatobiliary cancer. Metal stents are often used for palliative biliary drainage in these patients, but are currently seen as an absolute contraindication for IRE due to the perceived risk of direct heating of the metal and its surroundings. This study investigates the thermal and tissue viability changes due to a metal stent during IRE. METHODS IRE was performed in a homogeneous tissue model (polyacrylamide gel), without and with a metal stent placed perpendicular and parallel to the electrodes, delivering 90 and 270 pulses (15-35 A, 90 μsec, 1.5 cm active tip exposure, 1.5 cm interelectrode distance, 1000-1500 V/cm, 90 pulses/min), and in-vivo in a porcine liver (4 ablations). Temperature changes were measured with an infrared thermal camera and with fiber-optic probes. Tissue viability after in-vivo IRE was investigated macroscopically using 5-triphenyltetrazolium chloride (TTC) vitality staining. RESULTS In the gel, direct stent-heating was not observed. Contrarily, the presence of a stent between the electrodes caused a higher increase in median temperature near the electrodes (23.2 vs 13.3°C [90 pulses]; p = 0.021, and 33.1 vs 24.8°C [270 pulses]; p = 0.242). In-vivo, no temperature difference was observed for ablations with and without a stent. Tissue examination showed white coagulation 1mm around the electrodes only. A rim of vital tissue remained around the stent, whereas ablation without stent resulted in complete tissue avitality. CONCLUSION IRE in the vicinity of a metal stent does not cause notable direct heating of the metal, but results in higher temperatures around the electrodes and remnant viable tissue. Future studies should determine for which clinical indications IRE in the presence of metal stents is safe and effective.
Collapse
Affiliation(s)
- Hester J. Scheffer
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Jantien A. Vogel
- Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands
| | | | - Robert E. Neal
- Department of Radiology, The Alfred Hospital, Melbourne, Australia
| | | | | | - Martin J. C. van Gemert
- Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands
| | - Cees W. M. van der Geld
- Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Martijn R. Meijerink
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - John H. Klaessens
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - Rudolf M. Verdaasdonk
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
16
|
Abstract
Film is an excellent dosimeter for verification of dose distributions due to its high spatial resolution. Irradiated film can be digitized with low-cost, transmission, flatbed scanners. However, a disadvantage is their lateral scan effect (LSE): a scanner readout change over its lateral scan axis. Although anisotropic light scattering was presented as the origin of the LSE, this paper presents an alternative cause. Hereto, LSE for two flatbed scanners (Epson 1680 Expression Pro and Epson 10000XL), and Gafchromic film (EBT, EBT2, EBT3) was investigated, focused on three effects: cross talk, optical path length and polarization. Cross talk was examined using triangular sheets of various optical densities. The optical path length effect was studied using absorptive and reflective neutral density filters with well-defined optical characteristics (OD range 0.2-2.0). Linear polarizer sheets were used to investigate light polarization on the CCD signal in absence and presence of (un)irradiated Gafchromic film. Film dose values ranged between 0.2 to 9 Gy, i.e. an optical density range between 0.25 to 1.1. Measurements were performed in the scanner's transmission mode, with red-green-blue channels. LSE was found to depend on scanner construction and film type. Its magnitude depends on dose: for 9 Gy increasing up to 14% at maximum lateral position. Cross talk was only significant in high contrast regions, up to 2% for very small fields. The optical path length effect introduced by film on the scanner causes 3% for pixels in the extreme lateral position. Light polarization due to film and the scanner's optical mirror system is the main contributor, different in magnitude for the red, green and blue channel. We concluded that any Gafchromic EBT type film scanned with a flatbed scanner will face these optical effects. Accurate dosimetry requires correction of LSE, therefore, determination of the LSE per color channel and dose delivered to the film.
Collapse
Affiliation(s)
- L J van Battum
- Physics and Medical Technology, VU University Medical Center, Support Radiotherapy, PO Box 7057, 1007 MB Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
17
|
Scheffer HJ, Vogel JA, van den Bos W, Meijerink MR, Besselink MG, Verdaasdonk RM, Klaessens J, van der Geld CW, van Gemert MJ. Comment to: Månsson C, Nilsson A, Karlson B-M. Severe complications with irreversible electroporation of the pancreas in the presence of a metallic stent: a warning of a procedure that never should be performed. Acta Radiologica Short Reports 2014;3(11):1-3. Acta Radiol Open 2015; 4:2058460115584111. [PMID: 26759723 PMCID: PMC4548731 DOI: 10.1177/2058460115584111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 04/05/2015] [Indexed: 12/03/2022] Open
Affiliation(s)
- Hester J Scheffer
- Departments of Radiology and Nuclear Medicine, Free University Medical Center, Amsterdam, The Netherlands
| | - Jantien A Vogel
- Department of Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Willemien van den Bos
- Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Martijn R Meijerink
- Departments of Radiology and Nuclear Medicine, Free University Medical Center, Amsterdam, The Netherlands
| | - Marc Gh Besselink
- Department of Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Rudolf M Verdaasdonk
- Department of Physics and Medical Technology, Free University Medical Center, Amsterdam, The Netherlands
| | - John Klaessens
- Department of Physics and Medical Technology, Free University Medical Center, Amsterdam, The Netherlands
| | - Cees Wm van der Geld
- Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Martin Jc van Gemert
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
18
|
van Houdt PJ, Ossenblok PPW, Colon AJ, Hermans KHM, Verdaasdonk RM, Boon PAJM, de Munck JC. Are Epilepsy-Related fMRI Components Dependent on the Presence of Interictal Epileptic Discharges in Scalp EEG? Brain Topogr 2014; 28:606-18. [PMID: 25315607 DOI: 10.1007/s10548-014-0407-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 09/30/2014] [Indexed: 01/27/2023]
Abstract
Spatial independent component analysis (ICA) is increasingly being used to extract resting-state networks from fMRI data. Previous studies showed that ICA also reveals independent components (ICs) related to the seizure onset zone. However, it is currently unknown how these epileptic ICs depend on the presence of interictal epileptic discharges (IEDs) in the EEG. The goal of this study was to explore the relation between ICs obtained from fMRI epochs during the occurrence of IEDs in the EEG and those without IEDs. fMRI data sets with co-registered EEG were retrospectively selected of patients from whom the location of the epileptogenic zone was confirmed by outcome of surgery (n = 8). The fMRI data were split into two epochs: one with IEDs visible in scalp EEG and one without. Spatial ICA was applied to the fMRI data of each part separately. The maps of all resulting components were compared to the resection area and the EEG-fMRI correlation pattern by computing a spatial correlation coefficient to detect the epilepsy-related component. For all patients, except one, there was a remarkable resemblance between the epilepsy-related components selected during epochs with IEDs and those without IEDs. These findings suggest that epilepsy-related ICs are not dependent on the presence of IEDs in scalp EEG. Since these epileptic ICs showed partial overlap with resting-state networks of healthy volunteers (n = 10), our study supports the need for new ways to classify epileptic ICs.
Collapse
Affiliation(s)
- Petra J van Houdt
- Department of Research and Development, Kempenhaeghe, Heeze, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
19
|
He BJ, Nolte G, Nagata K, Takano D, Yamazaki T, Fujimaki Y, Maeda T, Satoh Y, Heckers S, George MS, Lopes da Silva F, de Munck JC, Van Houdt PJ, Verdaasdonk RM, Ossenblok P, Mullinger K, Bowtell R, Bagshaw AP, Keeser D, Karch S, Segmiller F, Hantschk I, Berman A, Padberg F, Pogarell O, Scharnowski F, Karch S, Hümmer S, Keeser D, Paolini M, Kirsch V, Koller G, Rauchmann B, Kupka M, Blautzik J, Pogarell O, Razavi N, Jann K, Koenig T, Kottlow M, Hauf M, Strik W, Dierks T, Gotman J, Vulliemoz S, Lu Y, Zhang H, Yang L, Worrell G, He B, Gruber O, Piguet C, Hubl D, Homan P, Kindler J, Dierks T, Kim K, Steinhoff U, Wakai R, Koenig T, Kottlow M, Melie-García L, Mucci A, Volpe U, Prinster A, Salvatore M, Galderisi S, Linden DEJ, Brandeis D, Schroeder CE, Kayser C, Panzeri S, Kleinschmidt A, Ritter P, Walther S, Haueisen J, Lau S, Flemming L, Sonntag H, Maess B, Knösche TR, Lanfer B, Dannhauer M, Wolters CH, Stenroos M, Haueisen J, Wolters C, Aydin U, Lanfer B, Lew S, Lucka F, Ruthotto L, Vorwerk J, Wagner S, Ramon C, Guan C, Ang KK, Chua SG, Kuah WK, Phua KS, Chew E, Zhou H, Chuang KH, Ang BT, Wang C, Zhang H, Yang H, Chin ZY, Yu H, Pan Y, Collins L, Mainsah B, Colwell K, Morton K, Ryan D, Sellers E, Caves K, Throckmorton S, Kübler A, Holz EM, Zickler C, Sellers E, Ryan D, Brown K, Colwell K, Mainsah B, Caves K, Throckmorton S, Collins L, Wennberg R, Ahlfors SP, Grova C, Chowdhury R, Hedrich T, Heers M, Zelmann R, Hall JA, Lina JM, Kobayashi E, Oostendorp T, van Dam P, Oosterhof P, Linnenbank A, Coronel R, van Dessel P, de Bakker J, Rossion B, Jacques C, Witthoft N, Weiner KS, Foster BL, Miller KJ, Hermes D, Parvizi J, Grill-Spector K, Recanzone GH, Murray MM, Haynes JD, Richiardi J, Greicius M, De Lucia M, Müller KR, Formisano E, Smieskova R, Schmidt A, Bendfeldt K, Walter A, Riecher-Rössler A, Borgwardt S, Fusar-Poli P, Eliez S, Schmidt A, Sekihara K, Nagarajan SS, Schoffelen JM, Guggisberg AG, Nolte G, Balazs S, Kermanshahi K, Kiesenhofer W, Binder H, Rattay F, Antal A, Chaieb L, Paulus W, Bodis-Wollner I, Maurer K, Fein G, Camchong J, Johnstone J, Cardenas-Nicolson V, Fiederer LDJ, Lucka F, Yang S, Vorwerk J, Dümpelmann M, Cosandier-Rimélé D, Schulze-Bonhage A, Aertsen A, Speck O, Wolters CH, Ball T, Fuchs M, Wagner M, Kastner J, Tech R, Dinh C, Haueisen J, Baumgarten D, Hämäläinen MS, Lau S, Vogrin SJ, D'Souza W, Haueisen J, Cook MJ, Custo A, Van De Ville D, Vulliemoz S, Grouiller F, Michel CM, Malmivuo J, Aydin U, Vorwerk J, Küpper P, Heers M, Kugel H, Wellmer J, Kellinghaus C, Scherg M, Rampp S, Wolters C, Storti SF, Boscolo Galazzo I, Del Felice A, Pizzini FB, Arcaro C, Formaggio E, Mai R, Manganotti P, Koessler L, Vignal J, Cecchin T, Colnat-Coulbois S, Vespignani H, Ramantani G, Maillard L, Rektor I, Kuba R, Brázdil M, Chrastina J, Rektorova I, van Mierlo P, Carrette E, Strobbe G, Montes-Restrepo V, Vonck K, Vandenberghe S, Ahmed B, Brodely C, Carlson C, Kuzniecky R, Devinsky O, French J, Thesen T, Bénis D, David O, Lachaux JP, Seigneuret E, Krack P, Fraix V, Chabardès S, Bastin J, Jann K, Gee D, Kilroy E, Cannon T, Wang DJ, Hale JR, Mayhew SD, Przezdzik I, Arvanitis TN, Bagshaw AP, Plomp G, Quairiaux C, Astolfi L, Michel CM, Mayhew SD, Mullinger KJ, Bagshaw AP, Bowtell R, Francis ST, Schouten AC, Campfens SF, van der Kooij H, Koles Z, Lind J, Flor-Henry P, Wirth M, Haase CM, Villeneuve S, Vogel J, Jagust WJ, Kambeitz-Ilankovic L, Simon-Vermot L, Gesierich B, Duering M, Ewers M, Rektorova I, Krajcovicova L, Marecek R, Mikl M, Bracht T, Horn H, Strik W, Federspiel A, Schnell S, Höfle O, Stegmayer K, Wiest R, Dierks T, Müller TJ, Walther S, Surmeli T, Ertem A, Eralp E, Kos IH, Skrandies W, Flüggen S, Klein A, Britz J, Díaz Hernàndez L, Ro T, Michel CM, Lenartowicz A, Lau E, Rodriguez C, Cohen MS, Loo SK, Di Lorenzo G, Pagani M, Monaco L, Daverio A, Giannoudas I, La Porta P, Verardo AR, Niolu C, Fernandez I, Siracusano A, Flor-Henry P, Lind J, Koles Z, Bollmann S, Ghisleni C, O'Gorman R, Poil SS, Klaver P, Michels L, Martin E, Ball J, Eich-Höchli D, Brandeis D, Salisbury DF, Murphy TK, Butera CD, Mathalon DH, Fryer SL, Kiehl KA, Calhoun VC, Pearlson GD, Roach BJ, Ford JM, McGlashan TH, Woods SW, Volpe U, Merlotti E, Vignapiano A, Montefusco V, Plescia GM, Gallo O, Romano P, Mucci A, Galderisi S, Mingoia G, Langbein K, Dietzek M, Wagner G, Smesny, Scherpiet S, Maitra R, Gaser C, Sauer H, Nenadic I, Gonzalez Andino S, Grave de Peralta Menendez R, Grave de Peralta Menendez R, Sanchez Vives M, Rebollo B, Gonzalez Andino S, Frølich L, Andersen TS, Mørup M, Belfiore P, Gargiulo P, Ramon C, Vanhatalo S, Cho JH, Vorwerk J, Wolters CH, Knösche TR, Watanabe T, Kawabata Y, Ukegawa D, Kawabata S, Adachi Y, Sekihara K, Sekihara K, Nagarajan SS, Wagner S, Aydin U, Vorwerk J, Herrmann C, Burger M, Wolters C, Lucka F, Aydin U, Vorwerk J, Burger M, Wolters C, Bauer M, Trahms L, Sander T, Faber PL, Lehmann D, Gianotti LRR, Pascual-Marqui RD, Milz P, Kochi K, Kaneko S, Yamashita S, Yana K, Kalogianni K, Vardy AN, Schouten AC, van der Helm FCT, Sorrentino A, Luria G, Aramini R, Hunold A, Funke M, Eichardt R, Haueisen J, Gómez-Aguilar F, Vázquez-Olvera S, Cordova-Fraga T, Castro-López J, Hernández-Gonzalez MA, Solorio-Meza S, Sosa-Aquino M, Bernal-Alvarado JJ, Vargas-Luna M, Vorwerk J, Magyari L, Ludewig J, Oostenveld R, Wolters CH, Vorwerk J, Engwer C, Ludewig J, Wolters C, Sato K, Nishibe T, Furuya M, Yamashiro K, Yana K, Ono T, Puthanmadam Subramaniyam N, Hyttinen J, Lau S, Güllmar D, Flemming L, Haueisen J, Sonntag H, Vorwerk J, Wolters CH, Grasedyck L, Haueisen J, Maeß B, Freitag S, Graichen U, Fiedler P, Strohmeier D, Haueisen J, Stenroos M, Hauk O, Grigutsch M, Felber M, Maess B, Herrmann B, Strobbe G, van Mierlo P, Vandenberghe S, Strobbe G, Cárdenas-Peña D, Montes-Restrepo V, van Mierlo P, Castellanos-Dominguez G, Vandenberghe S, Lanfer B, Paul-Jordanov I, Scherg M, Wolters CH, Ito Y, Sato D, Kamada K, Kobayashi T, Dalal SS, Rampp S, Willomitzer F, Arold O, Fouladi-Movahed S, Häusler G, Stefan H, Ettl S, Zhang S, Zhang Y, Li H, Kong X, Montes-Restrepo V, Strobbe G, van Mierlo P, Vandenberghe S, Wong DDE, Bidet-Caulet A, Knight RT, Crone NE, Dalal SS, Birot G, Spinelli L, Vulliémoz S, Seeck M, Michel CM, Emory H, Wells C, Mizrahi N, Vogrin SJ, Lau S, Cook MJ, Karahanoglu FI, Grouiller F, Caballero-Gaudes C, Seeck M, Vulliemoz S, Van De Ville D, Spinelli L, Megevand P, Genetti M, Schaller K, Michel C, Vulliemoz S, Seeck M, Genetti M, Tyrand R, Grouiller F, Vulliemoz S, Spinelli L, Seeck M, Schaller K, Michel CM, Grouiller F, Heinzer S, Delattre B, Lazeyras F, Spinelli L, Pittau F, Seeck M, Ratib O, Vargas M, Garibotto V, Vulliemoz S, Vogrin SJ, Bailey CA, Kean M, Warren AE, Davidson A, Seal M, Harvey AS, Archer JS, Papadopoulou M, Leite M, van Mierlo P, Vonck K, Boon P, Friston K, Marinazzo D, Ramon C, Holmes M, Koessler L, Rikir E, Gavaret M, Bartolomei F, Vignal JP, Vespignani H, Maillard L, Centeno M, Perani S, Pier K, Lemieux L, Clayden J, Clark C, Pressler R, Cross H, Carmichael DW, Spring A, Bessemer R, Pittman D, Aghakhani Y, Federico P, Pittau F, Grouiller F, Vulliémoz S, Gotman J, Badier JM, Bénar CG, Bartolomei F, Cruto C, Chauvel P, Gavaret M, Brodbeck V, van Leeuwen T, Tagliazzuchi E, Melloni L, Laufs H, Griskova-Bulanova I, Dapsys K, Klein C, Hänggi J, Jäncke L, Ehinger BV, Fischer P, Gert AL, Kaufhold L, Weber F, Marchante Fernandez M, Pipa G, König P, Sekihara K, Hiyama E, Koga R, Iannilli E, Michel CM, Bartmuss AL, Gupta N, Hummel T, Boecker R, Holz N, Buchmann AF, Blomeyer D, Plichta MM, Wolf I, Baumeister S, Meyer-Lindenberg A, Banaschewski T, Brandeis D, Laucht M, Natahara S, Ueno M, Kobayashi T, Kottlow M, Bänninger A, Koenig T, Schwab S, Koenig T, Federspiel A, Dierks T, Jann K, Natsukawa H, Kobayashi T, Tüshaus L, Koenig T, Kottlow M, Achermann P, Wilson RS, Mayhew SD, Assecondi S, Arvanitis TN, Bagshaw AP, Darque A, Rihs TA, Grouiller F, Lazeyras F, Ha-Vinh Leuchter R, Caballero C, Michel CM, Hüppi PS, Hauser TU, Hunt LT, Iannaccone R, Stämpfli P, Brandeis D, Dolan RJ, Walitza S, Brem S, Graichen U, Eichardt R, Fiedler P, Strohmeier D, Freitag S, Zanow F, Haueisen J, Lordier L, Grouiller F, Van de Ville D, Sancho Rossignol A, Cordero I, Lazeyras F, Ansermet F, Hüppi P, Schläpfer A, Rubia K, Brandeis D, Di Lorenzo G, Pagani M, Monaco L, Daverio A, Giannoudas I, Verardo AR, La Porta P, Niolu C, Fernandez I, Siracusano A, Tamura K, Karube C, Mizuba T, Matsufuji M, Takashima S, Iramina K, Assecondi S, Ostwald D, Bagshaw AP, Marecek R, Brazdil M, Lamos M, Slavícek T, Marecek R, Jan J, Meier NM, Perrig W, Koenig T, Minami T, Noritake Y, Nakauchi S, Azuma K, Minami T, Nakauchi S, Rodriguez C, Lenartowicz A, Cohen MS, Rodriguez C, Lenartowicz A, Cohen MS, Iramina K, Kinoshita H, Tamura K, Karube C, Kaneko M, Ide J, Noguchi Y, Cohen MS, Douglas PK, Rodriguez CM, Xia HJ, Zimmerman EM, Konopka CJ, Epstein PS, Konopka LM, Giezendanner S, Fisler M, Soravia L, Andreotti J, Wiest R, Dierks T, Federspiel A, Razavi N, Federspiel A, Dierks T, Hauf M, Jann K, Kamada K, Sato D, Ito Y, Okano K, Mizutani N, Kobayashi T, Thelen A, Murray M, Pastena L, Formaggio E, Storti SF, Faralli F, Melucci M, Gagliardi R, Ricciardi L, Ruffino G, Coito A, Macku P, Tyrand R, Astolfi L, He B, Wiest R, Seeck M, Michel C, Plomp G, Vulliemoz S, Fischmeister FPS, Glaser J, Schöpf V, Bauer H, Beisteiner R, Deligianni F, Centeno M, Carmichael DW, Clayden J, Mingoia G, Langbein K, Dietzek M, Wagner G, Smesny S, Scherpiet S, Maitra R, Gaser C, Sauer H, Nenadic I, Dürschmid S, Zaehle T, Pannek H, Chang HF, Voges J, Rieger J, Knight RT, Heinze HJ, Hinrichs H, Tsatsishvili V, Cong F, Puoliväli T, Alluri V, Toiviainen P, Nandi AK, Brattico E, Ristaniemi T, Grieder M, Crinelli RM, Jann K, Federspiel A, Wirth M, Koenig T, Stein M, Wahlund LO, Dierks T, Atsumori H, Yamaguchi R, Okano Y, Sato H, Funane T, Sakamoto K, Kiguchi M, Tränkner A, Schindler S, Schmidt F, Strauß M, Trampel R, Hegerl U, Turner R, Geyer S, Schönknecht P, Kebets V, van Assche M, Goldstein R, van der Meulen M, Vuilleumier P, Richiardi J, Van De Ville D, Assal F, Wozniak-Kwasniewska A, Szekely D, Harquel S, Bougerol T, David O, Bracht T, Jones DK, Horn H, Müller TJ, Walther S, Sos P, Klirova M, Novak T, Brunovsky M, Horacek J, Bares M, Hoschl C C, Fellhauer I, Zöllner FG, Schröder J, Kong L, Essig M, Schad LR, Arrubla J, Neuner I, Hahn D, Boers F, Shah NJ, Neuner I, Arrubla J, Hahn D, Boers F, Jon Shah N, Suriya Prakash M, Sharma R, Kawaguchi H, Kobayashi T, Fiedler P, Griebel S, Biller S, Fonseca C, Vaz F, Zentner L, Zanow F, Haueisen J, Rochas V, Rihs T, Thut G, Rosenberg N, Landis T, Michel C, Moliadze V, Schmanke T, Lyzhko E, Bassüner S, Freitag C, Siniatchkin M, Thézé R, Guggisberg AG, Nahum L, Schnider A, Meier L, Friedrich H, Jann K, Landis B, Wiest R, Federspiel A, Strik W, Dierks T, Witte M, Kober SE, Neuper C, Wood G, König R, Matysiak A, Kordecki W, Sieluzycki C, Zacharias N, Heil P, Wyss C, Boers F, Arrubla J, Dammers J, Kawohl W, Neuner I, Shah NJ, Braboszcz C, Cahn RB, Levy J, Fernandez M, Delorme A, Rosas-Martinez L, Milne E, Zheng Y, Urakami Y, Kawamura K, Washizawa Y, Hiyoshi K, Cichocki A, Giroud N, Dellwo V, Meyer M, Rufener KS, Liem F, Dellwo V, Meyer M, Jones-Rounds JD, Raizada R, Staljanssens W, Strobbe G, van Mierlo P, Van Holen R, Vandenberghe S, Pefkou M, Becker R, Michel C, Hervais-Adelman A, He W, Brock J, Johnson B, Ohla K, Hitz K, Heekeren K, Obermann C, Huber T, Juckel G, Kawohl W, Gabriel D, Comte A, Henriques J, Magnin E, Grigoryeva L, Ortega JP, Haffen E, Moulin T, Pazart L, Aubry R, Kukleta M, Baris Turak B, Louvel J, Crespo-Garcia M, Cantero JL, Atienza M, Connell S, Kilborn K, Damborská A, Brázdil M, Rektor I, Kukleta M, Koberda JL, Bienkiewicz A, Koberda I, Koberda P, Moses A, Tomescu M, Rihs T, Britz J, Custo A, Grouiller F, Schneider M, Debbané M, Eliez S, Michel C, Wang GY, Kydd R, Wouldes TA, Jensen M, Russell BR, Dissanayaka N, Au T, Angwin A, O'Sullivan J, Byrne G, Silburn P, Marsh R, Mellic G, Copland D, Bänninger A, Kottlow M, Díaz Hernàndez L, Koenig T, Díaz Hernàndez L, Bänninger A, Koenig T, Hauser TU, Iannaccone R, Mathys C, Ball J, Drechsler R, Brandeis D, Walitza S, Brem S, Boeijinga PH, Pang EW, Valica T, Macdonald MJ, Oh A, Lerch JP, Anagnostou E, Di Lorenzo G, Pagani M, Monaco L, Daverio A, Verardo AR, Giannoudas I, La Porta P, Niolu C, Fernandez I, Siracusano A, Shimada T, Matsuda Y, Monkawa A, Monkawa T, Hashimoto R, Watanabe K, Kawasaki Y, Matsuda Y, Shimada T, Monkawa T, Monkawa A, Watanabe K, Kawasaki Y, Stegmayer K, Horn H, Federspiel A, Razavi N, Bracht T, Laimböck K, Strik W, Dierks T, Wiest R, Müller TJ, Walther S, Koorenhof LJ, Swithenby SJ, Martins-Mourao A, Rihs TA, Tomescu M, Song KW, Custo A, Knebel JF, Murray M, Eliez S, Michel CM, Volpe U, Merlotti E, Vignapiano A, Montefusco V, Plescia GM, Gallo O, Romano P, Mucci A, Galderisi S, Laimboeck K, Jann K, Walther S, Federspiel A, Wiest R, Strik W, Horn H. Abstracts of Presentations at the International Conference on Basic and Clinical Multimodal Imaging (BaCI), a Joint Conference of the International Society for Neuroimaging in Psychiatry (ISNIP), the International Society for Functional Source Imaging (ISFSI), the International Society for Bioelectromagnetism (ISBEM), the International Society for Brain Electromagnetic Topography (ISBET), and the EEG and Clinical Neuroscience Society (ECNS), in Geneva, Switzerland, September 5-8, 2013. Clin EEG Neurosci 2013; 44:1550059413507209. [PMID: 24368763 DOI: 10.1177/1550059413507209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- B J He
- National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Stokbroekx T, de Boer A, Verdaasdonk RM, Vuylsteke ME, Mordon SR. Commonly used fiber tips in endovenous laser ablation (EVLA): an analysis of technical differences. Lasers Med Sci 2013; 29:501-7. [DOI: 10.1007/s10103-013-1475-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 11/28/2022]
|
21
|
Kamalski DMA, Verdaasdonk RM, de Boorder T, Vincent R, Trabelzini F, Grolman W. Comparison of KTP, Thulium, and CO2 laser in stapedotomy using specialized visualization techniques: thermal effects. Eur Arch Otorhinolaryngol 2013; 271:1477-83. [PMID: 23880918 DOI: 10.1007/s00405-013-2624-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 06/28/2013] [Indexed: 11/27/2022]
Abstract
High-speed thermal imaging enables visualization of heating of the vestibule during laser-assisted stapedotomy, comparing KTP, CO2, and Thulium laser light. Perforation of the stapes footplate with laser bears the risk of heating of the inner ear fluids. The amount of heating depends on absorption of the laser light and subsequent tissue ablation. The ablation of the footplate is driven by strong water absorption for the CO2 and Thulium laser. For the KTP laser wavelength, ablation is driven by carbonization of the footplate and it might penetrate deep into the inner ear without absorption in water. The thermal effects were visualized in an inner ear model, using two new techniques: (1) high-speed Schlieren imaging shows relative dynamic changes of temperatures up to 2 ms resolution in the perilymph. (2) Thermo imaging provides absolute temperature measurements around the footplate up to 40 ms resolution. The high-speed Schlieren imaging showed minimal heating using the KTP laser. Both CO2 and Thulium laser showed heating below the footplate. Thulium laser wavelength generated heating up to 0.6 mm depth. This was confirmed with thermal imaging, showing a rise of temperature of 4.7 (±3.5) °C for KTP and 9.4 (±6.9) for Thulium in the area of 2 mm below the footplate. For stapedotomy, the Thulium and CO2 laser show more extended thermal effects compared to KTP. High-speed Schlieren imaging and thermal imaging are complimentary techniques to study lasers thermal effects in tissue.
Collapse
Affiliation(s)
- Digna M A Kamalski
- Department of Otorhinolaryngology, University Medical Center Utrecht, Heidelberglaan 100, G05. 129, 3584 CX, Utrecht, The Netherlands,
| | | | | | | | | | | |
Collapse
|
22
|
Hofman MBM, Kuijer JPA, de Ridder JW, Perk LR, Verdaasdonk RM. Technical Note: Building a combined cyclotron and MRI facility: Implications for interference. Med Phys 2013; 40:012303. [DOI: 10.1118/1.4772188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
23
|
Cuper NJ, de Graaff JC, Verdaasdonk RM, Kalkman CJ. Near-infrared imaging in intravenous cannulation in children: a cluster randomized clinical trial. Pediatrics 2013; 131:e191-7. [PMID: 23230072 DOI: 10.1542/peds.2012-0968] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Intravenous cannulation is a widespread medical procedure that can be difficult in children. Visualization of veins with near-infrared (NIR) light might support intravenous cannulation. Therefore, we investigated the effectiveness of an NIR vascular imaging system (VascuLuminator) in facilitating intravenous cannulation in children in the operating room. METHODS This was a pragmatic, cluster randomized clinical trial in all consecutive children (0-18 years) scheduled for elective surgery and in need of intravenous cannulation at a tertiary pediatric referral hospital. Daily operating rooms (770 patients) were randomized for allocation of the VascuLuminator or control group. The primary outcome was success at first attempt; the secondary outcome was time to successful cannulation. RESULTS Success at first attempt was 70% (171/246) with and 71% (175/245) without the use of the VascuLuminator (P = .69). Time to successful cannulation was 162 (± 14) seconds and 143 (± 15) seconds respectively (P = .26). In 83.3%, the vein of first choice was visible with the VascuLuminator. CONCLUSIONS Although it was possible to visualize veins with NIR in most patients, the VascuLuminator did not improve success rate or time to obtain intravenous cannulation. There are 3 possible explanations for this result: first, it could be that localization of the vein is not the main problem, and therefore visualization is not a solution; second, the type of system used in this study could be less than optimal; and, third, the choice of the patient population in this study could be inappropriate.
Collapse
Affiliation(s)
- Natascha J Cuper
- Department of Medical Technology & Clinical Physics, University Medical Center, Utrecht, Netherlands, Netherlands.
| | | | | | | |
Collapse
|
24
|
van Gemert MJC, van der Geld CWM, Bruijninckx CMA, Verdaasdonk RM, Neumann HAM. Comment to Vuylsteke ME and Mordon SR. Endovenous laser ablation: a review of mechanisms of action. Ann Vasc Surg 2012;26:424-33. Ann Vasc Surg 2012; 26:881-3. [PMID: 22794335 DOI: 10.1016/j.avsg.2012.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 04/24/2012] [Indexed: 11/16/2022]
|
25
|
Cuper NJ, Klaessens JHG, Jaspers JEN, de Roode R, Noordmans HJ, de Graaff JC, Verdaasdonk RM. The use of near-infrared light for safe and effective visualization of subsurface blood vessels to facilitate blood withdrawal in children. Med Eng Phys 2012; 35:433-40. [PMID: 22841651 DOI: 10.1016/j.medengphy.2012.06.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 04/11/2012] [Accepted: 06/15/2012] [Indexed: 11/26/2022]
Abstract
Obtaining access to blood vessels can be difficult, especially in children. Visualization of subsurface blood vessels might be a solution. Ultrasound and visible light have been used to this purpose, but have some drawbacks. Near-infrared light might be a better option since subsurface blood vessels can be visualized in high contrast due to less absorption and scattering in tissue as compared to visible light. Our findings with a multispectral imaging system support this theory. A device, the VascuLuminator, was developed, based on transillumination of the puncture site with near-infrared light. The VascuLuminator was designed to meet the requirements of compact and safe use. A phantom study showed that the maximum depth of visibility (5.5mm for a 3.6mm blood vessel) is sufficient to visualize blood vessels in typical locations for peripheral venous and arterial access. A quantitative comparison of the VascuLuminator and to two other vessel imaging devices, using reflection of near-infrared light instead of transillumination, was conducted. The VascuLuminator is able to decrease failure at first attempt in blood withdrawal in pediatric patients from 10/80 (13%) to 1/45 (2%; P=.05).
Collapse
Affiliation(s)
- Natascha J Cuper
- Department of Medical Technology & Clinical Physics, University Medical Center, Utrecht, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
26
|
Cuper NJ, de Graaff JC, van Dijk ATH, Verdaasdonk RM, van der Werff DBM, Kalkman CJ. Predictive factors for difficult intravenous cannulation in pediatric patients at a tertiary pediatric hospital. Paediatr Anaesth 2012; 22:223-9. [PMID: 21851476 DOI: 10.1111/j.1460-9592.2011.03685.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND It is generally believed that certain patient characteristics (e.g., Body Mass Index and age) predict difficulty of intravenous cannulation in children, but there is not much literature evaluating these risk factors. In this study, we investigated predictive factors for success rate at first attempt and time needed for intravenous cannulation. METHODS/MATERIALS In a prospective cohort study, we observed characteristics of intravenous cannulations in pediatric patients at the operating room (n = 1083) and the outpatient care unit (n = 178) of a tertiary referral pediatric hospital. Time to successful intravenous cannulation, success at first attempt, and potential predictors for difficult cannulation (age, gender, skin color, BMI or weight-to-age z-score, the child being awake or anesthetized, operator profession and surgical specialty) were recorded. Regression models were constructed to find significant predictors. RESULTS Success at first attempt was 73% and 81%, respectively. In the operating room age, operator and surgical specialty were predictive for a successful first attempt and time to successful cannulation. No significant predictive factors were found for the outpatient care unit. BMI or weight-to-age was not related to difficult intravenous cannulation. CONCLUSIONS This study shows that in one-fifth to one-third of the patients, intravenous cannulation required more than one attempt. It is difficult to predict with accuracy the difficulty of intravenous cannulation solely with easily obtainable patient characteristics.
Collapse
Affiliation(s)
- Natascha J Cuper
- Department of Medical Technology & Clinical Physics, University Medical Center, Utrecht, the Netherlands.
| | | | | | | | | | | |
Collapse
|
27
|
Cuper NJ, Verdaasdonk RM, de Roode R, de Vooght KMK, Viergever MA, Kalkman CJ, de Graaff JC. Visualizing veins with near-infrared light to facilitate blood withdrawal in children. Clin Pediatr (Phila) 2011; 50:508-12. [PMID: 21357203 DOI: 10.1177/0009922810395932] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION This study aims to evaluate for the first time the value of visualizing veins by a prototype of a near-infrared (NIR) vascular imaging system for venipuncture in children. METHODS An observational feasibility study of venipunctures in children (0-6 years) attending the clinical laboratory of a pediatric university hospital during a period of 2 months without (n = 80) and subsequently during a period of 1 month with a prototype of an NIR vascular imaging system (n = 45) was conducted. Failure rate (ie, more than 1 puncture) and time of needle manipulation were determined. RESULTS With the NIR vascular imaging system, failure rate decreased from 10/80 to 1/45 (P = .05) and time decreased from 2 seconds (1-10) to 1 second (1-4, P = .07). CONCLUSION This study showed promising results on the value of an NIR vascular imaging system in facilitating venipunctures.
Collapse
|
28
|
Grimbergen MCM, van Swol CFP, Kendall C, Verdaasdonk RM, Stone N, Bosch JLHR. Signal-to-noise contribution of principal component loads in reconstructed near-infrared Raman tissue spectra. Appl Spectrosc 2010; 64:8-14. [PMID: 20132590 DOI: 10.1366/000370210790572052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The overall quality of Raman spectra in the near-infrared region, where biological samples are often studied, has benefited from various improvements to optical instrumentation over the past decade. However, obtaining ample spectral quality for analysis is still challenging due to device requirements and short integration times required for (in vivo) clinical applications of Raman spectroscopy. Multivariate analytical methods, such as principal component analysis (PCA) and linear discriminant analysis (LDA), are routinely applied to Raman spectral datasets to develop classification models. Data compression is necessary prior to discriminant analysis to prevent or decrease the degree of over-fitting. The logical threshold for the selection of principal components (PCs) to be used in discriminant analysis is likely to be at a point before the PCs begin to introduce equivalent signal and noise and, hence, include no additional value. Assessment of the signal-to-noise ratio (SNR) at a certain peak or over a specific spectral region will depend on the sample measured. Therefore, the mean SNR over the whole spectral region (SNR(msr)) is determined in the original spectrum as well as for spectra reconstructed from an increasing number of principal components. This paper introduces a method of assessing the influence of signal and noise from individual PC loads and indicates a method of selection of PCs for LDA. To evaluate this method, two data sets with different SNRs were used. The sets were obtained with the same Raman system and the same measurement parameters on bladder tissue collected during white light cystoscopy (set A) and fluorescence-guided cystoscopy (set B). This method shows that the mean SNR over the spectral range in the original Raman spectra of these two data sets is related to the signal and noise contribution of principal component loads. The difference in mean SNR over the spectral range can also be appreciated since fewer principal components can reliably be used in the low SNR data set (set B) compared to the high SNR data set (set A). Despite the fact that no definitive threshold could be found, this method may help to determine the cutoff for the number of principal components used in discriminant analysis. Future analysis of a selection of spectral databases using this technique will allow optimum thresholds to be selected for different applications and spectral data quality levels.
Collapse
Affiliation(s)
- M C M Grimbergen
- Dept. of Urology, University Medical Centre Utrecht, The Netherlands.
| | | | | | | | | | | |
Collapse
|
29
|
Blanken JW, Verdaasdonk RM. [Laser treatment in root canals. Effective by explosive vapour bubbles]. Ned Tijdschr Tandheelkd 2009; 116:355-360. [PMID: 19673234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Since the late eighties pulsed infrared lasers like the Er:YAG and the Er,Cr:YSGG lasers are available for dentists. These lasers appear to have interesting applications in endodontics. It was demonstrated in vitro, with dyes, that a root canal can effectively be irrigated with them. Initially these lasers were recommended for preparation of enamel, dentin and bone and for surgery. The way that it worked in a root canal in combination with a liquid was, however, not clear. With a special high speed imaging technique the working mechanism of a pulsed infrared laser was studied, using a model of a root canal in a basin filled with either water or with a 5% NaOCl solution. The working mechanism can be attributed to the high stream of liquid, the turbulence and the cavity-effects, created by explosive vapour bubbles. These phenomena appear to make a major contribution to the cleansing and disinfecting of the root canal.
Collapse
|
30
|
Abstract
Objectives The aim of this experimental study was to investigate the mechanism of action of endovenous laser ablation (EVLA) using an 810-nm diode laser. Methods We compared intermittent and continuous delivery of laser energy and studied the absorption of laser light by blood, intravascular temperatures in ex vivo human vein segments using an intravascular thermography catheter and heat dissipation in a model tissue using the Schlieren technique. Results Laser light is absorbed by blood and converted to heat leading to coagulation, vaporization and carbonization, and forming an isolating layer at the fibre tip. Laser energy is then absorbed into the isolating layer forming black patches that burned on the laser fibre. Intravascular temperature increased rapidly above carbonization temperatures (300°C) after the fibre tip reached the thermocouple, stayed at this temperature for a few seconds and decreased gradually to around 30°C, 10 s after the fibre tip passed the thermocouple. Schlieren techniques revealed that heat spread from the laser was locally distributed and closely around the laser fibre tip while heat dissipation is minimal and comparable for both exposures. Compared with intermittent exposure, continuous exposure results in more carbonization, higher mean maximum intravascular temperature (128 ± 7 vs. 75 ± 4°C), and long-lasting temperature of 100°C (1.2 ± 0.4 vs. 0.1 ± 0.1 s). Conclusion In this experimental study, application of endovenous laser shows to be dominated by carbonization at the fibre tip. Although intraluminal laser-induced heat was heterogeneously distributed, with laser tip temperatures up to 1200°C, heat dissipation was minimal. Continuous exposure of laser light appears to be better suited in EVLA than intermittent.
Collapse
Affiliation(s)
| | - A I Rem
- Department of Clinical Physics, University Medical Centre Utrecht
| | - R M Verdaasdonk
- Department of Clinical Physics, University Medical Centre Utrecht
| | | | - F L Moll
- Department of Vascular Surgery, University Medical Centre Utrecht, Utrecht, The Netherlands
| |
Collapse
|
31
|
van Beijnum J, Hanlo PW, Fischer K, Majidpour MM, Kortekaas MF, Verdaasdonk RM, Vandertop WP. LASER-ASSISTED ENDOSCOPIC THIRD VENTRICULOSTOMY. Neurosurgery 2008; 62:437-43; discussion 443-4. [DOI: 10.1227/01.neu.0000316011.13174.b1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE
Endoscopic third ventriculostomy is a well-known surgical option in the treatment of noncommunicating hydrocephalus. We studied complications and long-term success in 202 patients to demonstrate the safety and efficacy of laser-assisted endoscopic third ventriculostomy (LA-ETV) using a unique “black” fiber tip/diode laser combination for controlled tissue ablation.
METHODS
We studied 213 LA-ETVs, which were performed in 202 patients. Patients' ages ranged from 2 days to 83 years (mean age, 27 yr). The mean follow-up period for all patients was 2.7 years (range, 2 d to 12 yr). Hydrocephalus was caused by aqueductal stenosis in 65 patients, tumors in 67 patients, hemorrhages in 24 patients, myelomeningoceles in 20 patients, cysts in 15 patients, and other causes in 11 patients. The long-term effectiveness of LA-ETV was studied with Kaplan-Meier analysis.
RESULTS
Technically successful LA-ETVs were accomplished in 196 of the 202 patients (97%). The overall success rate for a functional LA-ETV was 68% at the 2-year follow-up evaluation. LA-ETV was more effective in patients aged 1 year and older (70% success rate) than in younger patients (59% success rate). Success rates were greater in patients with aqueductal stenosis or tumors as compared to other etiologies. Complications occurred in 22 procedures (10.3%). Only one patient (0.5%) experienced a major complication. No surgical mortalities or laser-related complications occurred.
CONCLUSION
This study demonstrates that LA-ETV is a safe and effective procedure that is comparable to other techniques for ETV. LA-ETV is most effective in patients aged 1 year and older and in patients with aqueductal stenosis and tumors, with a low major complication rate.
Collapse
Affiliation(s)
- Janneke van Beijnum
- Department of Neurosurgery, University Medical Center, Utrecht, The Netherlands
| | - Patrick W. Hanlo
- Department of Neurosurgery, University Medical Center, Utrecht, The Netherlands
| | - Kathelijn Fischer
- Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht, The Netherlands
| | - Mohsen M. Majidpour
- Department of Neurosurgery, University Medical Center, Utrecht, The Netherlands
| | | | | | - W. Peter Vandertop
- Department of Neurosurgery, Neurosurgical Center, Amsterdam, The Netherlands
| |
Collapse
|
32
|
Verdaasdonk RM, van Swol CFP, Grimbergen MCM, Rem AI. Imaging techniques for research and education of thermal and mechanical interactions of lasers with biological and model tissues. J Biomed Opt 2006; 11:041110. [PMID: 16965138 DOI: 10.1117/1.2338817] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A setup based on color Schlieren techniques has been developed to study the interaction of energy sources, such as lasers, with biological tissues. This imaging technique enables real-time visualization of dynamic temperature gradients with high spatial and temporal resolution within a transparent tissue model. High-speed imaging techniques were combined in the setup to capture mechanical phenomena such as explosive vapor, cavitation bubbles, and shock waves. The imaging technique is especially used for qualitative studies because it is complex to obtain quantitative data by relating the colors in the images to temperatures. By positioning thermocouples in the field of view, temperature figures can be added in the image for correlation to colored areas induced by the temperature gradients. The color Schlieren setup was successfully used for various studies to obtain a better understanding of interaction of various laser, rf, and ultrasound devices used in medicine. The results contributed to the safety and the optimal settings of various medical treatments. Although the interaction of energy sources is simulated in model tissue, the video clips have proven to be of great value for educating researchers, surgeons, nurses, and students to obtain a better understanding of the mechanism of action during patient treatment.
Collapse
Affiliation(s)
- Rudolf M Verdaasdonk
- University Medical Center, Utrecht, Department of Medical Physics, P.O. Box 85500, Zip 3508 GA, Utrecht, The Netherlands.
| | | | | | | |
Collapse
|
33
|
Van Beijnum J, Hanlo PW, Han KS, Ludo Van der Pol W, Verdaasdonk RM, Van Nieuwenhuizen O. Navigated laser-assisted endoscopic fenestration of a suprasellar arachnoid cyst in a 2-year-old child with bobble-head doll syndrome. J Neurosurg Pediatr 2006; 104:348-51. [PMID: 16848093 DOI: 10.3171/ped.2006.104.5.348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The authors present the case of a 2-year-old boy with bobble-head doll syndrome (BHDS) associated with a large suprasellar arachnoid cyst and enlarged ventricles, who was successfully treated with neuronavigated laser-assisted endoscopic ventriculocystocisternostomy. The clinical history, surgical treatment, and clinical follow up of the patient are described. A navigated laser-assisted endoscopic ventriculocystocisternostomy of the suprasellar arachnoid cyst led to cessation of the head bobbing, and notable reduction of the cyst and ventricles was visible on the postoperative magnetic resonance images. Caused by a suprasellar arachnoid cyst, BHDS can be successfully treated with navigated laser-assisted endoscopic ventriculocystocisternostomy. The advantages of this procedure are minimal invasiveness and facilitated guidance of the neuronavigation system to the target area when normal anatomical landmarks are not visible.
Collapse
Affiliation(s)
- Janneke Van Beijnum
- Department of Neurosurgery, University Medical Center, Utrecht, The Netherlands.
| | | | | | | | | | | |
Collapse
|
34
|
Abstract
During the last 10 years, there has been a revival of interest in cerebral revascularization procedures. Not only have significant progressions in surgical techniques been published, the use of more advanced diagnostic methods has led to a widening of the indications for cerebral bypass surgery. The purpose of this review is to outline the current techniques for extracranial-to-intracranial (EC/IC) and intracranial-to-intracranial (IC/IC) bypass surgery, as well as to identify the current indications for revascularization procedures based on the available literature. The excimer laser-assisted non-occlusive anastomosis (ELANA) technique is described in more detail because we think that this technique almost completely eliminates the risk of cerebral ischemia due to the temporary vessel occlusion which is currently used in conventional anastomosis techniques.
Collapse
Affiliation(s)
- H J N Streefkerk
- Department of Neurosurgery, Brain Division, University Medical Center-Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
35
|
Vandertop WP, van der Zwan A, Verdaasdonk RM. Third ventriculostomy. J Neurosurg 2001; 95:919-21. [PMID: 11702892 DOI: 10.3171/jns.2001.95.5.0919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Since its description by Dandy in 1922, several techniques have been used to perform third ventriculostomy under endoscopic control. Except for the blunt technique, in which the endoscope is used by itself to create the opening in the floor of the third ventricle, the other techniques require more than one instrument to perforate the floor of the ventricle and enlarge the ventriculostomy. The new device described is a sterilizable modified forceps that allows both the opening of the floor and the enlargement of the ventriculostomy in a simple and effective way. The new device has the following characteristics: 1) the tip of the forceps is thin enough to allow the easy perforation of the floor of the ventricle; 2) the inner surface of the jaws is smooth to avoid catching vessels of the basal cistern; and 3) the outer surface of the jaws has indentations that catch the edges of the opening to prevent them from slipping along the instrument's jaws. The ventricle floor is opened by gentle pressure of the forceps, which is slowly opened so that the edges of the aperture are caught by the distal outer indentation of the jaws, leading to an approximately 4-mm opening of the floor. This device has been used successfully in 10 consecutive patients. This new device allows surgeons to perform third ventriculostomy under endoscopic control in a very simple, quick, and effective way, avoiding the need for additional single-use instruments.
Collapse
|
36
|
Willems PW, Vandertop WP, Verdaasdonk RM, van Swol CF, Jansen GH. Contact laser-assisted neuroendoscopy can be performed safely by using pretreated 'black' fibre tips: experimental data. Lasers Surg Med 2001; 28:324-9. [PMID: 11344512 DOI: 10.1002/lsm.1057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE Laser-assisted endoscopic neurosurgery by using conventional fibres requires the use of high-power laser light. Because this is potentially hazardous, we developed a pretreated fibre tip and evaluated tissue effects in vitro and in vivo. STUDY DESIGN/MATERIALS AND METHODS By applying a highly absorbing coating to the front of the ball tip, almost all laser light is transformed into thermal energy, instantly producing ablative temperatures at the tip itself. The temperature distribution was examined by using an in vitro thermal imaging technique. The in vivo effect on rabbit cerebral tissue was examined macroscopically and histologically. RESULTS By using a conventional fibre tip, ablation was not observed, despite the use of high energy and power (20 W for 10 seconds), whereas histology and thermal imaging demonstrated deleterious effects deeply into the cerebral tissue. By using the coated fibre tip, ablation was observed at low energy and power (1 W for 1 second) with thermal effects restricted to superficial structures. CONCLUSIONS We show that laser-assisted neuroendoscopy can only be considered to be safe when pretreated "black" fibre tips are used, as laser light damages deep structures.
Collapse
Affiliation(s)
- P W Willems
- Department of Neurosurgery, University Hospital Utrecht, Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
37
|
Vandertop WP, Hanlo PW, Verdaasdonk RM. Cerebral infarction after neuroendoscopic third ventriculostomy: case report. Neurosurgery 2001; 48:453-4. [PMID: 11220397 DOI: 10.1097/00006123-200102000-00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
38
|
Abstract
AIM To assess the retinal phototoxicity hazards of and to provide safety margins for endoillumination during vitrectomy. METHODS The absolute power and spectral distribution from various light sources and filter combinations that are commercially available for vitreous surgery were measured. The maximal exposure times based on the ICNIRP safety guidelines for photochemical and thermal injury of the aphakic eye were calculated. Additionally, the effect of various measures that reduce the risk of phototoxicity was evaluated. RESULTS Measurements of the spectrum and energy indicated that the ICNIRP safety guidelines for photochemical retinal damage are exceeded within 1 minute for nine out of 10 combinations tested. With an additional 475 nm long pass filter, light levels below 10 mW, and a distance from light probe to retina of at least 10 mm, the allowable exposure time can be increased up to 13 minutes. Thermal damage can be anticipated when the light probe touches the retina. CONCLUSION Commercially available light sources for endoillumination during vitrectomy are not safe with respect to photochemical retinal damage. Even with maximal precautions macular phototoxic damage remains a factual danger during vitrectomy.
Collapse
Affiliation(s)
- P R van den Biesen
- FC Donders Institute of Ophthalmology, University Hospital Utrecht, Utrecht, Netherlands.
| | | | | | | | | |
Collapse
|
39
|
van Swol CF, van Vliet RJ, Verdaasdonk RM, Boon TA. Electrovaporization as a treatment modality for transurethral resection of the prostate: influence of generator type. Urology 1999; 53:317-21. [PMID: 9933047 DOI: 10.1016/s0090-4295(98)00496-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To study the influence of the electrosurgical generator on the vaporization efficacy during electrovaporization (EVAP) using different vaporization elements. METHODS Electrical properties of human prostatic (in vivo) and bovine myocardium (in vitro) tissue were measured under electroresection and electrovaporization conditions. The effective output power of four different generators ("old generation" Force 4 and Force 40 and "new generation" Force 300 and Force FX) was measured at different impedance loads. In vitro, the coagulation and vaporization capabilities of the electrosurgical generators in combination with resection and vaporization elements were studied on homogeneous tissue (bovine myocardium). RESULTS The electrical impedance of human prostatic tissue and bovine myocardium increases from 400 to 1000 ohms when coagulated. The effective output power of the old generation electrosurgical devices depends strongly on tissue impedance. This implies that working on already coagulated tissue using such devices is not well controlled and not reproducible. By contrast, new generation electrosurgical devices correct for the higher impedance of coagulated tissue, thus delivering constant output power and corresponding tissue effects. CONCLUSIONS For an effective application of the EVAP technique, the use of a new generation impedance independent electrosurgical unit is highly recommended.
Collapse
Affiliation(s)
- C F van Swol
- Department of Urology, University Hospital Utrecht, The Netherlands
| | | | | | | |
Collapse
|
40
|
te Slaa E, van Swol CF, Boon TA, Verdaasdonk RM, Doesburg WH, Debruyne FM, de la Rosette JJ. Influence of decay of laser fibers during laser prostatectomy on clinical results. J Endourol 1998; 12:291-5. [PMID: 9658305 DOI: 10.1089/end.1998.12.291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Three types of sidefiring laser fibers (34 Urolase, 20 Ultraline, and 114 Prolase II) were visually inspected after a laser prostatectomy, and transmission measurements were performed using a power meter (Aquarius). The results were correlated with the clinical outcome. Despite differences in the amount of loss in transmission for the fibers used, we could not establish any significant effect on clinical outcome measures, such as improvement in maximal flow rate or symptom score. The visual aspect of the Urolase fibers was significantly related to the amount of transmission loss, whereas no such relation was found for the other two types of fibers. Prostate size and the total amount of energy delivered by the laser source also did not correlate with the clinical outcome. To determine the relation between the energy absorbed by the prostate and clinical outcome, a large number of patients must be evaluated, and any factor that can be controlled needs to be monitored. For the latter, the power meter as presented here is a useful complementary tool.
Collapse
Affiliation(s)
- E te Slaa
- Department of Urology, University Hospital Nijmegen, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
41
|
Vandertop WP, Verdaasdonk RM, van Swol CF. Laser-assisted neuroendoscopy using a neodymium-yttrium aluminum garnet or diode contact laser with pretreated fiber tips. J Neurosurg 1998; 88:82-92. [PMID: 9420077 DOI: 10.3171/jns.1998.88.1.0082] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECT Although lasers have proved to be valuable in neuroendoscopy, surgeons are still not comfortable using high-energy laser endoscopic probes in proximity to vital structures such as the basilar artery in third ventriculostomy. The authors have developed a special laser catheter for use in neuroendoscopy; the object of this paper is to present their experimental and clinical experiences using the catheter. METHODS This laser catheter is fitted with an atraumatic ball-shaped fiber tip that is pretreated with a layer of carbon particles. These carbon particles absorb approximately 90% of the energy emitted, which is very effectively converted into heat. As the heat is generated in this very thin layer of carbon coating, the temperature at the surface of the ball-shaped tip reaches ablative temperatures instantly at powers of only a few watts per second, which has enabled the authors to limit drastically the amount of laser light used and the length of exposure needed, thereby increasing safety even around critical structures. CONCLUSIONS The authors present experimental data and their clinical experience using these pretreated fiber tips with a neodymium-yttrium aluminum garnet contact laser or a diode contact laser in 49 patients (22 males and 27 females) and a variety of procedures: third ventriculocistemostomy (33 patients), cyst fenestration (nine patients), colloid cyst resection (six patients), and fenestration of the septum pellucidum (one patient). There was no instance of mortality or increased morbidity. To date, the procedure success rate is 100% and the overall outcome success rate is 86%. The authors conclude that pretreated atraumatic ball-shaped fiber tips now make laser application safe and effective in a variety of neuroendoscopic procedures. Because of their low power range (only several watts), compact diode lasers will be the energy source of first choice.
Collapse
Affiliation(s)
- W P Vandertop
- Department of Neurosurgery, University Hospital, Utrecht, The Netherlands.
| | | | | |
Collapse
|
42
|
Abstract
BACKGROUND High-flow extraintracranial bypass operation on the brain is a risky procedure because of the temporary occlusion of the intracranial portion of the internal carotid artery. We therefore developed a nonocclusive anastomosis technique in the experimental animal laboratory in 100 chronic and acute experiments in rabbits. METHODS In 40 patients we interposed a venous transplant between the external carotid artery or one of its branches and the intracranial portion of the internal carotid artery. During the construction of the distal anastomosis the recipient artery was not occluded. The donor vessel was stitched to the exterior of the recipient vessel and an Excimer laser catheter (Medolas GmbH, Amberg, Germany) was introduced by way of an artificial side branch. The tip of the laser catheter created a hole in the wall of the recipient artery just inside the anastomosis. The cut-out full-thickness portion of recipient vessel wall remained attached to the tip of the laser catheter by way of high vacuum suction and was removed together with the laser catheter. The artificial side branch was occluded with a hemostatic clip. No interruption of blood flow in the recipient artery was induced during the making of the anastomosis. RESULTS The procedure was well tolerated by the patients and a high patency rate was observed. CONCLUSIONS The nonocclusive Excimer laser-assisted anastomosis technique is safe and yields a high long-term patency rate in neurosurgical patients. It cannot be excluded that there are indications for this method in coronary bypass surgery.
Collapse
Affiliation(s)
- C A Tulleken
- Department of Neurosurgery, Medical Laser Center, University Hospital, Utrecht, the Netherlands
| | | | | |
Collapse
|
43
|
Abstract
For medical applications, the choice of a delivery system will be governed by the characteristics of the laser system on the one hand and the tissue application on the other. The most important parts are the beam guide and the target optics. Most lasers have wavelengths in the visible and near-infrared and can be transported by silica fibres. For the mid- and far-IR other fibre materials or hollow waveguides are used. At the end of the waveguide or fibre, an optically active component is present to direct the beam and to control the power density on the target tissue. The laser beam can be delivered either by focusing handpieces and scanning devices to treat superficial areas or through microscopes, endoscopes and flexible fibres to treat areas almost anywhere inside the human body. The characteristics of the delivery systems can be determined looking at beam properties, transmission and thermal properties. The delivery of continuous wave or pulsed laser energy, contact or non-contact, will determine the contribution of optical, thermal and mechanical effects to the tissue. The practical use of laser delivery systems is illustrated by various clinical applications.
Collapse
Affiliation(s)
- R M Verdaasdonk
- Department of Biomedical Engineering and Clinical Physics, University Hospital Utrecht, The Netherlands
| | | |
Collapse
|
44
|
Abstract
BACKGROUND To make high-flow revascularization of the brain possible, we developed an anastomosis technique that obviates temporary occlusion of the recipient artery. After connecting donor and recipient vessels, an Excimer laser catheter, introduced by way of an artificial side branch, creates a hole at the anastomosis site. Because of the inconsistency of the diameter of the hole produced by the closed laser tip, we developed an extensive modification of the procedure. METHODS A new type of laser tip was developed, consisting of two layers of 60 mu laser fibers in a circular configuration with a diameter of 2.2 mm. The laser tip is fixed to the vessel wall at the anastomosis site by suction with a high-vacuum suction device, and a round piece of recipient vessel wall inside the anastomosis is cut out. RESULTS Using the aorta as the recipient vessel in 30 rabbits, the modified technique was developed and, in the end, produced anastomoses with a high patency rate. In 25 patients, high-flow bypasses for different indications were made using a venous transplant interposed between the external carotid artery or one of its branches and the intracranial internal carotid artery, utilizing the modified Excimer laser technique for the intracranial anastomosis. Complications related to the new anastomosis technique were minimal, and a satisfactory patency rate was obtained. CONCLUSIONS The modified Excimer laser-assisted anastomosis technique makes high-flow revascularization of the brain a safe procedure, since temporary occlusion of the recipient proximal brain artery during the making of the anastomosis is obviated.
Collapse
Affiliation(s)
- C A Tulleken
- Department of Neurosurgery, University Hospital, Utrecht, The Netherlands
| | | | | | | |
Collapse
|
45
|
Van Swol CF, te Slaa E, Verdaasdonk RM, de la Rosette JJ, Boon TA. Variation in output power of laser prostatectomy fibers: a need for power measurements. Urology 1996; 47:672-7; discussion 677-8. [PMID: 8650864 DOI: 10.1016/s0090-4295(96)00005-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVES The aim of this study was the assessment of the quality of side-firing fibers that are being used for laser prostatectomy, either by a laser light transmission measurement or by visual inspection. METHODS A power meter (Aquarius) was developed to measure the actual power transmitted through a side-firing fiber and delivered to the prostatic tissue. The power measurements were performed under clinical conditions, that is, under water and at relatively high input power. Furthermore, a protocol was developed for visual inspection of the fibers. Eight types of side-firing fibers were measured before use. Before and after a procedure, three fiber types were measured: ProLase II (28 samples), UltraLine (23 samples), and UroLase (44 samples). All these fibers were used in standard treatment protocols. RESULTS At 60 W the transmission of new fibers (not used) ranged between 49% and 83% when compared to a bare fiber. After use, a large variation was found in transmitted power between different samples of one device. A correlation with total transmitted power was not present. At higher power input, vapor bubbles are generated at the tip of the fibers. Depending on the fiber design, these bubbles have a major impact on the transmission. Only for the UroLase fiber was there a significant correlation between visual inspection and the transmission of used samples at 10, 20, and 40 W. CONCLUSIONS The transmission strongly varies between fibers and between different samples of one fiber during clinical use. Moreover, the transmission does not correlate with visual inspection. A power measurement during a clinical treatment will contribute to a more controlled procedure and to a better comparison of clinical laser prostatectomy studies.
Collapse
Affiliation(s)
- C F Van Swol
- Department of Urology, Medical Laser Center, University Hospital Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
46
|
Boon TA, van Swol CF, van Venrooij GE, Beerlage HP, Verdaasdonk RM. Laser prostatectomy for patients with benign prostatic hyperplasia: a prospective randomized study comparing two different techniques using the Prolase-II fiber. World J Urol 1995; 13:123-5. [PMID: 7542965 DOI: 10.1007/bf00183628] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Laser prostatectomy for patients with complaints due to benign prostatic hyperplasia is a relatively new treatment option. The most effective procedure for coagulation and vaporization of the prostate is not yet known. In a prospective randomized study of 30 patients, 2 techniques for the delivery of laser energy were compared at 40 W for 90 s. The complications were minimal and antegrade ejaculation was preserved in 15 of 18 potent men. In 24 patients urodynamics evaluation was possible. In both groups a significant reduction in the symptom score was observed. The decrease in detrusor pressure at maximal flow and the increase in flow rate were, however, disappointing. No significant difference in the results was found between the two groups. The power setting needs to be changed in further studies.
Collapse
Affiliation(s)
- T A Boon
- Department of Urology, University Hospital Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
47
|
Abstract
Transurethral laser coagulation of the prostate has become an accepted treatment for benign prostatic hyperplasia (BPH). The most common method is the use of a sideward-firing fiber that, once inserted in the prostatic area, irradiates the abundant prostatic tissue with Nd:YAG laser light. In this study, eight different side-firing fibers that are commercially available were evaluated. The devices can be characterized by the way laser light is deflected sideward and by their thermal behavior. Most of the eight devices differ with regard to the angle at which the laser beam is deflected, the spot size on the irradiated tissue surface, and the heating of the device itself. Implementation of the optical and thermal characteristics of each device in the treatment protocol will contribute to the optimal use of laser energy for prostatectomy.
Collapse
Affiliation(s)
- C F van Swol
- Department of Urology, University Hospital Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
48
|
Abstract
A new type of revascularization of the brain is used in patients with brain ischaemia, caused by an occlusion of one or both internal carotid arteries, and in patients in whom the internal carotid artery has been deliberately occluded for the treatment of a giant aneurysm of the internal carotid artery. A so-called high flow extra-intracranial bypass operation is performed. An arterial or venous transplant is interposed between a branch of the external carotid artery or the external carotid artery itself and the intracranial portion of the internal carotid artery. The anastomosis with the intracranial portion of the internal carotid artery is made without temporary occlusion of the recipient artery and with the aid of the newly developed Excimer laser assisted anastomosis technique. The results of animal experiments and of a clinical series of 9 patients are reported.
Collapse
Affiliation(s)
- C A Tulleken
- Department of Neurosurgery, University Hospital, Utrecht, The Netherlands
| | | |
Collapse
|
49
|
Boon TA, van Swol CF, van Venrooij GE, de Gier RP, Verdaasdonk RM. [Laser prostatectomy as alternative to transurethral prostate resection in benign prostatic hyperplasia]. Ned Tijdschr Geneeskd 1994; 138:1760-3. [PMID: 7523960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Assessment of the results of laser prostatectomy, as a treatment for benign prostatic hyperplasia (BPH). DESIGN Prospective case control study. SETTING University Hospital Utrecht, the Netherlands. METHOD Between February 1992 and May 1993, 54 men with their micturition complaints due to BPH were treated with laser prostatectomy (TULIP system). Results were assessed using the international prostatic symptom score (IPSS), the maximal flow and urodynamic tests. The results were compared retrospectively with results of transurethral resection of the prostate (TURP; n = 40): both groups were urodynamically identical. RESULTS Of the 54 patients, 10 could not be evaluated 6 months after treatment (5 of them underwent TURP or a second laser prostatectomy). In 40 patients complete evaluation including urodynamics before and six months after treatment was possible. A significant decrease in the symptom score from 19.3 (SD: 7.6) to 6.3 (SD: 5.4) and increase of the maximal flow during pressure-flow studies from 9.6 to 15.8 ml per second were observed. The decrease of the voiding pressure at 6 months after TURP in comparison with laser prostatectomy was close to significance (p = 0.05); the other improvements after urodynamics were comparable. CONCLUSION Laser prostatectomy is a promising new therapy for BPH.
Collapse
Affiliation(s)
- T A Boon
- Afd. Urologie, Academisch Ziekenhuis, Utrecht
| | | | | | | | | |
Collapse
|
50
|
Abstract
The technique of laser-assisted anastomosis for high-flow bypass surgery using the excimer laser is described in 15 rabbits and in one patient. The left common carotid artery of the rabbits was excised and, with two anastomoses, connected to the right common carotid artery. An end-to-side anastomosis technique was used that obviated the temporary occlusion of the recipient artery. The end of the donor artery was connected for its full circumference with the exterior of the recipient artery and, with the aid of an excimer laser catheter (introduced via an artificial side branch of the donor artery), the wall of the recipient artery was evaporated. In two animals only, occlusion of the anastomosis sites occurred. In the remaining 13 animals both anastomosis sites were proven to be patent by inspection at different times, followed by scanning electron microscopy in six animals. In a patient with hypoperfusion of the brain caused by bilateral internal carotid artery occlusion, revascularization of the right hemisphere was obtained by placing a shunt between the proximal superficial temporal artery and the intracranial portion of the internal carotid artery, using a free transplant of the right inferior epigastric artery. The anastomosis with the internal carotid artery was created using the excimer laser-assisted technique without occlusion of the recipient artery.
Collapse
Affiliation(s)
- C A Tulleken
- Department of Neurosurgery, University Hospital, Utrecht, The Netherlands
| | | | | | | |
Collapse
|