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Thiem DGE, Stephan D, Ziebart A, Ruemmler R, Riedel J, Vinayahalingam S, Al-Nawas B, Blatt S, Kämmerer PW. Effects of volume management on free flap perfusion and metabolism in a large animal model study. Lab Anim (NY) 2024; 53:268-275. [PMID: 39122993 PMCID: PMC11439732 DOI: 10.1038/s41684-024-01410-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 06/27/2024] [Indexed: 08/12/2024]
Abstract
Free flap failure represents a substantial clinical burden. The role of intraoperative volume management remains controversial, with valid studies lacking. Here, using a large animal model, we investigated the influence of volume management on free flap perfusion and metabolism. Autotransfer of a musculocutaneous gracilis flap was performed on 31 German domestic pigs, with arterial anastomosis and catheterization of the pedicle vein for sequential blood sampling. Flap reperfusion was followed by induction of a hemorrhagic shock with maintenance for 30 min and subsequent circulation stabilization with crystalloid solution, crystalloid solution and catecholamine, autotransfusion or colloidal solution. Flap perfusion and oxygenation were periodically assessed using hyperspectral imaging. Flap metabolism was assessed via periodic blood gas analyses. Hyperspectral imaging revealed no difference in either superficial or deep tissue oxygen saturation, tissue hemoglobin or tissue water content between the test groups at any time point. Blood gas analyses showed that lactate levels were significantly increased in the group that received crystalloid solution and catecholamine, after circulatory stabilization and up to 2 h after. We conclude that, in hemorrhagic shock, volume management impacts acid-base balance in free flaps. Crystalloid solutions with norepinephrine increase lactate levels, yet short-term effects on flap perfusion seem minimal, suggesting that vasopressors are not detrimental.
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Affiliation(s)
- Daniel G E Thiem
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Daniel Stephan
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Alexander Ziebart
- Department of Anaesthesiology, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Robert Ruemmler
- Department of Anaesthesiology, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Julian Riedel
- Department of Anaesthesiology, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Shankeeth Vinayahalingam
- Department of Oral and Maxillofacial Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bilal Al-Nawas
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Sebastian Blatt
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Peer W Kämmerer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
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Al-Aroomi MA, Duan W, Al-Worafi NA, Al-Moraissi EA, Mashrah MA, Liu M, Xue X, Sun C. Radial and Ulnar Forearm Free Flaps: A Critical Comparison of Donor-Site Morbidity and Its Impact on Quality of Life. Plast Reconstr Surg 2024; 154:650-661. [PMID: 37621015 DOI: 10.1097/prs.0000000000011022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
BACKGROUND A poor evidence basis exists regarding directly comparing objective and subjective donor-site morbidity associated with the forearm flap. The authors evaluated the postoperative donor-site complications and quality-of-life outcomes between the radial forearm free flap (RFFF) and the ulnar forearm free flap (UFFF). METHODS All patients undergoing RFFF or UFFF harvest were included. Grip strength, pinch strength, wrist range of movement, and testing of skin sensitivity were assessed with the appropriate scales at different time intervals. In addition, appearance and quality of life were assessed using the Patient and Observer Scar Assessment Scale and the Disabilities of Arm, Shoulder, and Hand instruments. RESULTS Eighty patients were enrolled (RFFF, n = 40; and UFFF, n = 40). A short-term reduction in grip strength, fine motor skills (tip pinch, key pinch, palmar pinch), and range of motion was observed for the RFFF group and improved over time. None of the patients in either group experienced functional disturbance in grip strength, wrist motion, fine motor skills, or sensation to light touch at 1 year. Nine patients experienced partial skin graft loss (RFFF, n = 6; UFFF, n = 3). There was a significantly higher incidence of temporary numbness in the RFFF group ( P = 0.040). Persistent numbness occurred in 3 cases in the RFFF group. Cold intolerance was significantly lower in the UFFF group (2.5%) than in RFFF group (22.5%). Moreover, the mean Patient and Observer Scar Assessment Scale and Disabilities of Arm, Shoulder, and Hand scores were reduced at 12 months compared with 6 months, significantly superior for UFFF. CONCLUSIONS Objective function limitations are reversible short-term effects after forearm flap and do not affect daily routines in the long term. In addition, UFFF appears to be preferred over RFFF for subjective outcomes, which emphasizes that UFFF should be considered as an alternative to RFFF for reconstructing soft-tissue defects. CLINICAL QUESTION/LEVEL OF EVIDENCE Therapeutic, III.
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Affiliation(s)
| | - Weiyi Duan
- From the Departments of Oral and Maxillofacial Surgery
| | | | | | - Mubarak Ahmed Mashrah
- Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Stomatology Hospital of Guangzhou Medical University
| | - Minda Liu
- From the Departments of Oral and Maxillofacial Surgery
| | - Xiaomeng Xue
- From the Departments of Oral and Maxillofacial Surgery
| | - Changfu Sun
- From the Departments of Oral and Maxillofacial Surgery
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Schulz T, Köhler H, Kohler LH, Langer S, Nuwayhid R. Hyperspectral Imaging Detects Clitoral Vascular Issues in Gender-Affirming Surgery. Diagnostics (Basel) 2024; 14:1252. [PMID: 38928666 PMCID: PMC11202724 DOI: 10.3390/diagnostics14121252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/02/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
The aim of this study was to assess the efficacy of hyperspectral imaging (HSI) as an intraoperative perfusion imaging modality during gender affirmation surgery (GAS). The hypothesis posited that HSI could quantify perfusion to the clitoral complex, thereby enabling the prediction of either uneventful wound healing or the occurrence of necrosis. In this non-randomised prospective clinical study, we enrolled 30 patients who underwent GAS in the form of vaginoplasty with the preparation of a clitoral complex from 2020 to 2024 and compared patients' characteristics as well as HSI data regarding clitoris necrosis. Individuals demonstrating uneventful wound healing pertaining to the clitoral complex were designated as Group A. Patients with complete necrosis of the neo-clitoris were assigned to Group B. Patient characteristics were collected and subsequently a comparative analysis carried out. No significant difference in patient characteristics was observed between the two groups. Necrosis occurred when both StO2 and NIR PI parameters fell below 40%. For the simultaneous occurrence of StO2 and NIR PI of 40% or less, a sensitivity of 92% and specificity of 72% was calculated. Intraoperatively, the onset of necrosis in the clitoral complex can be reliably predicted with the assistance of HSI.
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Affiliation(s)
- Torsten Schulz
- Department of Orthopaedic, Trauma and Plastic Surgery, University Hospital Leipzig, 04103 Leipzig, Germany; (S.L.); (R.N.)
| | - Hannes Köhler
- Innovation Center Computer Assisted Surgery (ICCAS), University of Leipzig, 04103 Leipzig, Germany;
| | | | - Stefan Langer
- Department of Orthopaedic, Trauma and Plastic Surgery, University Hospital Leipzig, 04103 Leipzig, Germany; (S.L.); (R.N.)
| | - Rima Nuwayhid
- Department of Orthopaedic, Trauma and Plastic Surgery, University Hospital Leipzig, 04103 Leipzig, Germany; (S.L.); (R.N.)
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Qasim AB, Motta A, Studier-Fischer A, Sellner J, Ayala L, Hübner M, Bressan M, Özdemir B, Kowalewski KF, Nickel F, Seidlitz S, Maier-Hein L. Test-time augmentation with synthetic data addresses distribution shifts in spectral imaging. Int J Comput Assist Radiol Surg 2024; 19:1021-1031. [PMID: 38483702 PMCID: PMC11178652 DOI: 10.1007/s11548-024-03085-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 02/22/2024] [Indexed: 06/15/2024]
Abstract
PURPOSE Surgical scene segmentation is crucial for providing context-aware surgical assistance. Recent studies highlight the significant advantages of hyperspectral imaging (HSI) over traditional RGB data in enhancing segmentation performance. Nevertheless, the current hyperspectral imaging (HSI) datasets remain limited and do not capture the full range of tissue variations encountered clinically. METHODS Based on a total of 615 hyperspectral images from a total of 16 pigs, featuring porcine organs in different perfusion states, we carry out an exploration of distribution shifts in spectral imaging caused by perfusion alterations. We further introduce a novel strategy to mitigate such distribution shifts, utilizing synthetic data for test-time augmentation. RESULTS The effect of perfusion changes on state-of-the-art (SOA) segmentation networks depended on the organ and the specific perfusion alteration induced. In the case of the kidney, we observed a performance decline of up to 93% when applying a state-of-the-art (SOA) network under ischemic conditions. Our method improved on the state-of-the-art (SOA) by up to 4.6 times. CONCLUSION Given its potential wide-ranging relevance to diverse pathologies, our approach may serve as a pivotal tool to enhance neural network generalization within the realm of spectral imaging.
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Affiliation(s)
- Ahmad Bin Qasim
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Helmholtz Information and Data Science School for Health, Karlsruhe/Heidelberg, Germany.
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany.
| | - Alessandro Motta
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Alexander Studier-Fischer
- Department of General, Visceral, and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Jan Sellner
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Helmholtz Information and Data Science School for Health, Karlsruhe/Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- National Center for Tumor Diseases (NCT), NCT Heidelberg, A Partnership between DKFZ and University Medical Center Heidelberg, Heidelberg, Germany
| | - Leonardo Ayala
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marco Hübner
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
| | - Marc Bressan
- Department of General, Visceral, and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Berkin Özdemir
- Department of General, Visceral, and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Karl Friedrich Kowalewski
- Department of General, Visceral, and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
- Department of Urology, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany
| | - Felix Nickel
- Department of General, Visceral, and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Silvia Seidlitz
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Helmholtz Information and Data Science School for Health, Karlsruhe/Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- National Center for Tumor Diseases (NCT), NCT Heidelberg, A Partnership between DKFZ and University Medical Center Heidelberg, Heidelberg, Germany
| | - Lena Maier-Hein
- Division of Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Helmholtz Information and Data Science School for Health, Karlsruhe/Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- National Center for Tumor Diseases (NCT), NCT Heidelberg, A Partnership between DKFZ and University Medical Center Heidelberg, Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
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5
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Fiedler LS, Daaloul H. An overview of current assessment techniques for evaluating cutaneous perfusion in reconstructive surgery. JOURNAL OF BIOPHOTONICS 2024; 17:e202400002. [PMID: 38596828 DOI: 10.1002/jbio.202400002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/30/2024] [Accepted: 04/02/2024] [Indexed: 04/11/2024]
Abstract
This article provides a comprehensive analysis of modern techniques used in the assessment of cutaneous flaps in reconstructive surgery. It emphasizes the importance of preoperative planning and intra- and perioperative assessment of flap perfusion to ensure successful outcomes. Despite technological advancements, direct clinical assessment remains the gold standard. We categorized assessment techniques into non-invasive and invasive modalities, discussing their strengths and weaknesses. Non-invasive methods, such as acoustic Doppler sonography, near-infrared spectroscopy, hyperspectral imaging thermal imaging, and remote-photoplethysmography, offer accessibility and safety but may sacrifice specificity. Invasive techniques, including contrast-enhanced ultrasound, computed tomography angiography, near-infrared fluorescence angiography with indocyanine green, and implantable Doppler probe, provide high accuracy but introduce additional risks. We emphasize the need for a tailored decision-making process based on specific clinical scenarios, patient characteristics, procedural requirements, and surgeon expertise. It also discusses potential future advancements in flap assessment, including the integration of artificial intelligence and emerging technologies.
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Affiliation(s)
- Lukas Sebastian Fiedler
- ENT and Head and Neck Surgery, Plastic Operations, SLK Kliniken Heilbronn, Heilbronn, Germany
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Houda Daaloul
- Department of Neurology, Klinikum Rechts der Isar, Medical Faculty, Technical University of Munich, Munich, Germany
- Caire Health AI GmbH, Munich, Germany
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Gustafsson N, Bunke J, Magnusson L, Albinsson J, Hérnandez-Palacios J, Sheikh R, Malmsjö M, Merdasa A. Optimizing clinical O 2 saturation mapping using hyperspectral imaging and diffuse reflectance spectroscopy in the context of epinephrine injection. BIOMEDICAL OPTICS EXPRESS 2024; 15:1995-2013. [PMID: 38495727 PMCID: PMC10942706 DOI: 10.1364/boe.506492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/27/2023] [Accepted: 11/19/2023] [Indexed: 03/19/2024]
Abstract
Clinical determination of oxygen saturation (sO2) in patients is commonly performed via non-invasive optical techniques. However, reliance on a few wavelengths and some form of pre-determined calibration introduces limits to how these methods can be used. One example involves the assessment of sO2 after injection of local anesthetic using epinephrine, where some controversy exists around the time it takes for the epinephrine to have an effect. This is likely caused by a change in the tissue environment not accounted for by standard calibrated instruments and conventional analysis techniques. The present study aims to account for this changing environment by acquiring absorption spectra using hyperspectral imaging (HSI) and diffuse reflectance spectroscopy (DRS) before, during, and after the injection of local anesthesia containing epinephrine in human volunteers. We demonstrate the need to account for multiple absorbing species when applying linear spectral unmixing in order to obtain more clinically relevant sO2 values. In particular, we demonstrate how the inclusion of water absorption greatly affects the rate at which sO2 seemingly drops, which in turn sheds light on the current debate regarding the time required for local anesthesia with epinephrine to have an effect. In general, this work provides important insight into how spectral analysis methods need to be adapted to specific clinical scenarios to more accurately assess sO2.
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Affiliation(s)
- Nils Gustafsson
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
- NanoLund and Solid State Physics, Lund University, SE-221 00, Lund, Sweden
| | - Josefine Bunke
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
| | - Ludvig Magnusson
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
| | - John Albinsson
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
| | - Julio Hérnandez-Palacios
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
| | - Rafi Sheikh
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
| | - Malin Malmsjö
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
| | - Aboma Merdasa
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Ophthalmology, Lund, Sweden
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7
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Felicio-Briegel A, Linek M, Sroka R, Rühm A, Freymüller C, Stocker M, Baumeister P, Reichel C, Volgger V. Hyperspectral imaging for monitoring of free flaps of the oral cavity: A feasibility study. Lasers Surg Med 2024; 56:165-174. [PMID: 38247042 DOI: 10.1002/lsm.23756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 12/23/2023] [Accepted: 12/26/2023] [Indexed: 01/23/2024]
Abstract
OBJECTIVES Hyperspectral imaging (HSI) provides spectral information about hemoglobin, water and oxygen supply and has thus great potential in perfusion monitoring. The aim of the present study was to investigate the feasibility of HSI in the postoperative monitoring of intraoral free flaps. METHODS The 14 patients receiving reconstructive head and neck surgery with a radial forearm free flap were included. HSI was performed intraoperatively (t0), on Day 1 (t1), 2 (t2), 3-6 (t3), 7-9 (t4), 10-11 (t5) and 12-15 (t6) postoperatively. Flap tissue perfusion was assessed on defined regions of interest by calculating the perfusion indices Tissue Hemoglobin Index (THI), hemoglobin oxygenation (StO2 ), Near Infrared Perfusion Index (NIR Perfusion Index) and Tissue Water Index (TWI). RESULTS Image quality varied depending on location of the flap and time of measurement. StO2 was >50 intraoperatively and >40 on t1 for all patients. A significant difference was found solely for TWI between t0 and t2 and t0 and t4. No flap loss occurred. CONCLUSIONS The use of HSI in the monitoring of intraoral flaps is feasible and might become a valuable addition to the current clinical examination of free flaps.
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Affiliation(s)
| | - Matthäus Linek
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
| | - Ronald Sroka
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Adrian Rühm
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Christian Freymüller
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
| | - Magdalena Stocker
- Department of Otorhinolaryngology, University Hospital Salzburg, Salzburg, Austria
| | - Philipp Baumeister
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
| | - Christoph Reichel
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
| | - Veronika Volgger
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
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Stephan D, Blatt S, Riedel J, Mohnke K, Ruemmler R, Ziebart A, Al-Nawas B, Kämmerer PW, Thiem DGE. The Impact of Transfer-Related Ischemia on Free Flap Metabolism and Electrolyte Homeostasis-A New In Vivo Experimental Approach in Pigs. J Clin Med 2023; 12:6625. [PMID: 37892763 PMCID: PMC10607031 DOI: 10.3390/jcm12206625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Free flap tissue transfer represents the gold standard for extensive defect reconstruction, although malperfusion due to thrombosis remains the leading risk factor for flap failure. Recent studies indicate an increased immune response and platelet activation in connection with pathologic coagulation. The underlying cellular and molecular mechanisms remain poorly understood, however. The presented study, therefore, aims to investigate if transfer-related ischemia alters intra-flap metabolism and electrolyte concentrations compared to central venous blood after free flap transfer in pigs to establish a novel experimental model. Free transfer of a myocutaneous gracilis flap to the axillary region was conducted in five juvenile male pigs. The flap artery was anastomosed to the axillary artery, and intra-flap venous blood was drained and transfused using a rubber-elastic fixed intravenous catheter. Blood gas analysis was performed to assess the effect of transfer time-induced ischemia on intra-flap electrolyte levels, acid-base balance, and hemoglobin concentrations compared to central venous blood. Time to flap reperfusion was 52 ± 10 min on average, resulting in a continuous pH drop (acidosis) in the flaps' venous blood compared to the central venous system (p = 0.037). Potassium (p = 0.016), sodium (p = 0.003), and chloride (p = 0.007) concentrations were significantly increased, whereas bicarbonate (p = 0.016) and calcium (p = 0.008) significantly decreased within the flap. These observations demonstrate the induction of anaerobic glycolysis and electrolyte displacement resulting in acidosis and hence significant tissue damage already after a short ischemic period, thereby validating the novel animal model for investigating intra-flap metabolism and offering opportunities for exploring various (immuno-) thrombo-hemostatic issues in transplantation surgery.
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Affiliation(s)
- Daniel Stephan
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131 Mainz, Germany; (S.B.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Sebastian Blatt
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131 Mainz, Germany; (S.B.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Julian Riedel
- Department of Anaesthesiology, University Medical Centre, Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; (J.R.); (K.M.); (R.R.); (A.Z.)
| | - Katja Mohnke
- Department of Anaesthesiology, University Medical Centre, Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; (J.R.); (K.M.); (R.R.); (A.Z.)
| | - Robert Ruemmler
- Department of Anaesthesiology, University Medical Centre, Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; (J.R.); (K.M.); (R.R.); (A.Z.)
| | - Alexander Ziebart
- Department of Anaesthesiology, University Medical Centre, Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; (J.R.); (K.M.); (R.R.); (A.Z.)
| | - Bilal Al-Nawas
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131 Mainz, Germany; (S.B.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Peer W. Kämmerer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131 Mainz, Germany; (S.B.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Daniel G. E. Thiem
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131 Mainz, Germany; (S.B.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
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9
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Kämmerer PW, Al-Nawas B. Bone reconstruction of extensive maxillomandibular defects in adults. Periodontol 2000 2023; 93:340-357. [PMID: 37650475 DOI: 10.1111/prd.12499] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/21/2023] [Accepted: 05/26/2023] [Indexed: 09/01/2023]
Abstract
Reconstruction of significant maxillomandibular defects is a challenge that has been much discussed over the last few decades. Fundamental principles were developed decades ago (bone bed viability, graft immobilization). Clinical decision-making criteria are highly relevant, including local/systemic factors and incision designs, the choice of material, grafting technique, and donor site morbidity. Stabilizing particulated grafts for defined defects-that is, via meshes or shells-might allow significant horizontal and vertical augmentation; the alternatives are onlay and inlay techniques. More significant defects might require extra orally harvested autologous bone blocks. The anterior iliac crest is often used for nonvascularized augmentation, whereas more extensive defects often require microvascular reconstruction. In those cases, the free fibula flap has become the standard of care. The development of alternatives is still ongoing (i.e., alloplastic reconstruction, zygomatic implants, obturators, distraction osteogenesis). Especially for these complex procedures, three-dimensional planning tools enable facilitated planning and a surgical workflow.
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Affiliation(s)
- Peer W Kämmerer
- Department of Oral and Maxillofacial Surgery, University Medical Center Mainz, Mainz, Germany
| | - Bilal Al-Nawas
- Department of Oral and Maxillofacial Surgery, University Medical Center Mainz, Mainz, Germany
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10
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Schulz T, Nuwayhid R, Houschyar KS, Langer S, Kohler L. Diagnostical accuracy of hyperspectral imaging after free flap surgery. J Plast Surg Hand Surg 2023; 58:48-55. [PMID: 37614177 DOI: 10.2340/jphs.v58.7140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 05/25/2023] [Indexed: 08/25/2023]
Abstract
Microsurgical free-tissue transfer has been a safe option for tissue reconstruction. This study aimed to analyze the diagnostic accuracy of hyperspectral imaging (HSI) after free-tissue transfer surgery. From January 2017 to October 2019, 42 consecutive free-flap surgeries were performed, and their outcomes were analyzed via HSI. Clinical examination of free-flap perfusion was initially performed. Clinical examination findings were subsequently compared with those of HSI. Potential venous congestion with subsequent necrosis was defined as a tissue hemoglobin index of ≥53%. Student's t-test was used to compare the results of the analysis. The evaluation of sensitivity and specificity for flap failure detection was time dependent using the Fisher's exact test. A p-value of ≤0.05 was considered statistically significant. Microsurgical tissue transfer success rate was 84%. Seven patients presented with venous congestion that caused total flap necrosis. Overall, 124 assessments were made. HSI accurately identified 12 out of 19 pathological images: four as false positive and seven as false negative. The sensitivity and specificity of HSI were 57 and 94%, respectively, compared to those of clinical examination that were 28 and 100%, respectively, within 24 h following tissue transfer. The sensitivity and specificity of HSI were 63 and 96%, respectively, compared to those of clinical examination that were 63 and 100%, respectively, within the first 72 h. A tissue hemoglobin index of ≥53% could predict venous congestion after free-flap surgery. HSI demonstrated higher sensitivity than clinical examination within the first 24 h; however, it was not superior compared to clinical findings within 72 h.
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Affiliation(s)
- Torsten Schulz
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany.
| | - Rima Nuwayhid
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | | | - Stefan Langer
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Lukas Kohler
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany; Division of Hand-, Plastic- and Aesthetic Surgery, University Hospital Munich, Munich, Germany
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Tran MH, Fei B. Compact and ultracompact spectral imagers: technology and applications in biomedical imaging. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:040901. [PMID: 37035031 PMCID: PMC10075274 DOI: 10.1117/1.jbo.28.4.040901] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 02/27/2023] [Indexed: 05/18/2023]
Abstract
Significance Spectral imaging, which includes hyperspectral and multispectral imaging, can provide images in numerous wavelength bands within and beyond the visible light spectrum. Emerging technologies that enable compact, portable spectral imaging cameras can facilitate new applications in biomedical imaging. Aim With this review paper, researchers will (1) understand the technological trends of upcoming spectral cameras, (2) understand new specific applications that portable spectral imaging unlocked, and (3) evaluate proper spectral imaging systems for their specific applications. Approach We performed a comprehensive literature review in three databases (Scopus, PubMed, and Web of Science). We included only fully realized systems with definable dimensions. To best accommodate many different definitions of "compact," we included a table of dimensions and weights for systems that met our definition. Results There is a wide variety of contributions from industry, academic, and hobbyist spaces. A variety of new engineering approaches, such as Fabry-Perot interferometers, spectrally resolved detector array (mosaic array), microelectro-mechanical systems, 3D printing, light-emitting diodes, and smartphones, were used in the construction of compact spectral imaging cameras. In bioimaging applications, these compact devices were used for in vivo and ex vivo diagnosis and surgical settings. Conclusions Compact and ultracompact spectral imagers are the future of spectral imaging systems. Researchers in the bioimaging fields are building systems that are low-cost, fast in acquisition time, and mobile enough to be handheld.
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Affiliation(s)
- Minh H. Tran
- University of Texas at Dallas, Department of Bioengineering, Richardson, Texas, United States
| | - Baowei Fei
- University of Texas at Dallas, Department of Bioengineering, Richardson, Texas, United States
- University of Texas Southwestern Medical Center, Department of Radiology, Dallas, Texas, United States
- University of Texas at Dallas, Center for Imaging and Surgical Innovation, Richardson, Texas, United States
- Address all correspondence to Baowei Fei,
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Ellebrecht DB. Hyperspectral imaging enables the differentiation of differentially inflated and perfused pulmonary tissue: a proof-of-concept study in pulmonary lobectomies for intersegmental plane mapping. BIOMED ENG-BIOMED TE 2023:bmt-2022-0389. [PMID: 36932645 DOI: 10.1515/bmt-2022-0389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/02/2023] [Indexed: 03/19/2023]
Abstract
OBJECTIVES The identification of the intersegmental plane is a major interoperative challenges during pulmonary segmentectomies. The objective of this pilot study is to test the feasibility of lung perfusion assessment by Hyperspectral Imaging for identification of the intersegmental plane. METHODS A pilot study (clinicaltrials.org: NCT04784884) was conducted in patients with lung cancer. Measuring tissue oxygenation (StO2; upper tissue perfusion), organ hemoglobin index (OHI), near-infrared index (NIR; deeper tissue perfusion) and tissue water index (TWI), the Hyperspectral Imaging measurements were carried out in inflated (Pvent) and deflated pulmonary lobes (PnV) as well as in deflated pulmonary lobes with divided circulation (PnVC) before dissection of the lobar bronchus. RESULTS A total of 341 measuring points were evaluated during pulmonary lobectomies. Pulmonary lobes showed a reduced StO2 (Pvent: 84.56% ± 3.92 vs. PnV: 63.62% ± 11.62 vs. PnVC: 39.20% ± 23.57; p<0.05) and NIR-perfusion (Pvent: 50.55 ± 5.62 vs. PnV: 47.55 ± 3.38 vs. PnVC: 27.60 ± 9.33; p<0.05). There were no differences of OHI and TWI between the three groups. CONCLUSIONS This pilot study demonstrates that HSI enables differentiation between different ventilated and perfused pulmonary tissue as a precondition for HSI segment mapping.
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Affiliation(s)
- David B Ellebrecht
- Department of Thoracic Surgery, LungClinic Großhansdorf, Großhansdorf, Germany
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Combining Electrostimulation with Impedance Sensing to Promote and Track Osteogenesis within a Titanium Implant. Biomedicines 2023; 11:biomedicines11030697. [PMID: 36979676 PMCID: PMC10045247 DOI: 10.3390/biomedicines11030697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/03/2023] [Accepted: 02/17/2023] [Indexed: 03/02/2023] Open
Abstract
(1) Background: Electrical stimulation is a promising alternative to promote bone fracture healing but with the limitation of tracking the osteogenesis progress in vivo. To overcome this issue, we present an opportunity to combine the electrical stimulation of a commercial titanium implant, which promotes osteogenesis within the fracture, with a real-time readout of the osteogenic progress by impedance sensing. This makes it possible to adjust the electrical stimulation modalities to the individual patient’s fracture healing process. (2) Methods: In detail, osteogenic differentiation of several cell types was monitored under continuous or pulsatile electrical stimulation at 0.7 V AC/20 Hz for at least seven days on a titanium implant by electric cell-substrate impedance sensing (ECIS). For control, chemical induction of osteogenic differentiation was induced. (3) Results: The most significant challenge was to discriminate impedance changes caused by proliferation events from those initiated by osteogenic differentiation. This discrimination was achieved by remodeling the impedance parameter Alpha (α), which increases over time for pulsatile electrically stimulated stem cells. Boosted α-values were accompanied by an increased formation of actin stress fibers and a reduced expression of the focal adhesion kinase in the cell periphery; morphological alterations known to occur during osteogenesis. (4) Conclusions: This work provided the basis for developing an effective fracture therapy device, which can induce osteogenesis on the one hand, and would allow us to monitor the induction process on the other hand.
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Ellebrecht DB, Kugler C. Intraoperative Determination of Bronchus Stump and Anastomosis Perfusion with Hyperspectral Imaging. Surg Innov 2023:15533506231157165. [PMID: 36802983 DOI: 10.1177/15533506231157165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
BACKGROUND The intraoperative evaluation of bronchus perfusion is limited. Hyperspectral Imaging (HSI) is a newly established intraoperative imaging technique that enables a non-invasive, real-time perfusion analysis. Therefore, the purpose of this study was to determine the intraoperative perfusion of bronchus stump and anastomosis during pulmonary resections with HSI. METHODS In this prospective, IDEAL Stage 2a study (Clinicaltrials.gov: NCT04784884) HSI measurements were carried out before bronchial dissection and after bronchial stump formation or bronchial anastomosis, respectively. Tissue oxygenation (StO2; upper tissue perfusion), organ hemoglobin index (OHI), near-infrared index (NIR; deeper tissue perfusion) and tissue water index (TWI) were calculated. RESULTS Bronchus stumps showed a reduced NIR (77.82 ± 10.27 vs 68.01 ± 8.95; P = 0,02158) and OHI (48.60 ± 1.39 vs 38.15 ± 9.74; P = <.0001), although the perfusion of the upper tissue layers was equivalent before and after resection (67.42% ± 12.53 vs 65.91% ± 10.40). In the sleeve resection group, we found both a significant decrease in StO 2 and NIR between central bronchus and anastomosis region (StO2: 65.09% ± 12.57 vs 49.45 ± 9.94; P = .044; NIR: 83.73 ± 10.92 vs 58.62 ± 3.01; P = .0063). Additionally, NIR was decreased in the re-anastomosed bronchus compared to central bronchus region (83.73 ± 10.92 vs 55.15 ± 17.56; P = .0029). CONCLUSIONS Although both bronchus stumps and anastomosis show an intraoperative reduction of tissue perfusion, there is no difference of tissue hemoglobin level in bronchus anastomosis.
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Affiliation(s)
- David B Ellebrecht
- Department of Surgery, 9213LungClinic Großhansdorf, Großhansdorf, Germany
| | - Christian Kugler
- Department of Surgery, 9213LungClinic Großhansdorf, Großhansdorf, Germany
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Dietrich M, Antonovici A, Hölle T, Nusshag C, Kapp AC, Studier-Fischer A, Arif R, Nickel F, Weigand MA, Frey N, Lichtenstern C, Leuschner F, Fischer D. Microcirculatory tissue oxygenation correlates with kidney function after transcatheter aortic valve implantation-Results from a prospective observational study. Front Cardiovasc Med 2023; 10:1108256. [PMID: 36865886 PMCID: PMC9971913 DOI: 10.3389/fcvm.2023.1108256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/20/2023] [Indexed: 02/16/2023] Open
Abstract
Introduction Kidney dysfunction is common in patients with aortic stenosis (AS) and correction of the aortic valve by transcatheter aortic valve implantation (TAVI) often affects kidney function. This may be due to microcirculatory changes. Methods We evaluated skin microcirculation with a hyperspectral imaging (HSI) system, and compared tissue oxygenation (StO2), near-infrared perfusion index (NIR), tissue hemoglobin index (THI) and tissue water index (TWI) in 40 patients undergoing TAVI versus 20 control patients. HSI parameters were measured before TAVI (t1), directly after TAVI (t2), and on postinterventional day 3 (t3). The primary outcome was the correlation of tissue oxygenation (StO2) to the creatinine level after TAVI. Results We performed 116 HSI image recordings in patients undergoing TAVI for the treatment of severe aortic stenosis and 20 HSI image recordings in control patients. Patients with AS had a lower THI at the palm (p = 0.034) and a higher TWI at the fingertips (p = 0.003) in comparison to control patients. TAVI led to an increase of TWI, but had no uniform enduring effect on StO2 and THI. Tissue oxygenation StO2 at both measurement sites correlated negatively with creatinine levels after TAVI at t2 (palm: ρ = -0.415; p = 0.009; fingertip: ρ = -0.519; p < 0.001) and t3 (palm: ρ = -0.427; p = 0.008; fingertip: ρ = -0.398; p = 0.013). Patients with higher THI at t3 reported higher physical capacity and general health scores 120 days after TAVI. Conclusion HSI is a promising technique for periinterventional monitoring of tissue oxygenation and microcirculatory perfusion quality, which are related to kidney function, physical capacity, and clinical outcomes after TAVI. Clinical trial registration https://drks.de/search/de/trial, identifier DRKS00024765.
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Affiliation(s)
- Maximilian Dietrich
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany,*Correspondence: Maximilian Dietrich, ; orcid.org/0000-0003-0960-038X
| | - Ana Antonovici
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Tobias Hölle
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christian Nusshag
- Department of Nephrology, Heidelberg University Hospital, Heidelberg, Germany
| | - Anne-Christine Kapp
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Studier-Fischer
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Rawa Arif
- Institute of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Felix Nickel
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Norbert Frey
- Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Florian Leuschner
- Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany
| | - Dania Fischer
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
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Schraven SP, Kossack B, Strüder D, Jung M, Skopnik L, Gross J, Hilsmann A, Eisert P, Mlynski R, Wisotzky EL. Continuous intraoperative perfusion monitoring of free microvascular anastomosed fasciocutaneous flaps using remote photoplethysmography. Sci Rep 2023; 13:1532. [PMID: 36707664 PMCID: PMC9883527 DOI: 10.1038/s41598-023-28277-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/16/2023] [Indexed: 01/29/2023] Open
Abstract
Flap loss through limited perfusion remains a major complication in reconstructive surgery. Continuous monitoring of perfusion will facilitate early detection of insufficient perfusion. Remote or imaging photoplethysmography (rPPG/iPPG) as a non-contact, non-ionizing, and non-invasive monitoring technique provides objective and reproducible information on physiological parameters. The aim of this study is to establish rPPG for intra- and postoperative monitoring of flap perfusion in patients undergoing reconstruction with free fasciocutaneous flaps (FFCF). We developed a monitoring algorithm for flap perfusion, which was evaluated in 15 patients. For 14 patients, ischemia of the FFCF in the forearm and successful reperfusion of the implanted FFCF was quantified based on the local signal. One FFCF showed no perfusion after reperfusion and devitalized in the course. Intraoperative monitoring of perfusion with rPPG provides objective and reproducible results. Therefore, rPPG is a promising technology for standard flap perfusion monitoring on low costs without the need for additional monitoring devices.
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Affiliation(s)
- Sebastian P Schraven
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Doberaner Straße 137-139, 18057, Rostock, Germany.
| | - Benjamin Kossack
- Vision and Imaging Technologies, Fraunhofer Heinrich Hertz Institute HHI, Einsteinufer 37, 10587, Berlin, Germany.
| | - Daniel Strüder
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Doberaner Straße 137-139, 18057, Rostock, Germany
| | - Maximillian Jung
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Doberaner Straße 137-139, 18057, Rostock, Germany
| | - Lotte Skopnik
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Doberaner Straße 137-139, 18057, Rostock, Germany
| | - Justus Gross
- Department of General, Visceral, Thoracic, Vascular and Transplantation Surgery, Rostock University Medical Center, Schillingallee 35, 18057, Rostock, Germany
| | - Anna Hilsmann
- Vision and Imaging Technologies, Fraunhofer Heinrich Hertz Institute HHI, Einsteinufer 37, 10587, Berlin, Germany
| | - Peter Eisert
- Vision and Imaging Technologies, Fraunhofer Heinrich Hertz Institute HHI, Einsteinufer 37, 10587, Berlin, Germany
- Visual Computing, Institut für Informatik, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
| | - Robert Mlynski
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Doberaner Straße 137-139, 18057, Rostock, Germany
| | - Eric L Wisotzky
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Doberaner Straße 137-139, 18057, Rostock, Germany.
- Vision and Imaging Technologies, Fraunhofer Heinrich Hertz Institute HHI, Einsteinufer 37, 10587, Berlin, Germany.
- Visual Computing, Institut für Informatik, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany.
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Knoedler S, Hoch CC, Huelsboemer L, Knoedler L, Stögner VA, Pomahac B, Kauke-Navarro M, Colen D. Postoperative free flap monitoring in reconstructive surgery-man or machine? Front Surg 2023; 10:1130566. [PMID: 36911625 PMCID: PMC9992807 DOI: 10.3389/fsurg.2023.1130566] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/07/2023] [Indexed: 02/24/2023] Open
Abstract
Free tissue transfer is widely used for the reconstruction of complex tissue defects. The survival of free flaps depends on the patency and integrity of the microvascular anastomosis. Accordingly, the early detection of vascular comprise and prompt intervention are indispensable to increase flap survival rates. Such monitoring strategies are commonly integrated into the perioperative algorithm, with clinical examination still being considered the gold standard for routine free flap monitoring. Despite its widespread acceptance as state of the art, the clinical examination also has its pitfalls, such as the limited applicability in buried flaps and the risk of poor interrater agreement due to inconsistent flap (failure) appearances. To compensate for these shortcomings, a plethora of alternative monitoring tools have been proposed in recent years, each of them with inherent strengths and limitations. Given the ongoing demographic change, the number of older patients requiring free flap reconstruction, e.g., after cancer resection, is rising. Yet, age-related morphologic changes may complicate the free flap evaluation in elderly patients and delay the prompt detection of clinical signs of flap compromise. In this review, we provide an overview of currently available and employed methods for free flap monitoring, with a special focus on elderly patients and how senescence may impact standard free flap monitoring strategies.
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Affiliation(s)
- Samuel Knoedler
- Department of Plastic, Hand and Reconstructive Surgery, University Hospital Regensburg, Regensburg, Germany
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
- Correspondence: Samuel Knoedler Martin Kauke-Navarro
| | - Cosima C. Hoch
- Department of Otolaryngology, Head and Neck Surgery, Rechts der Isar Hospital, Technical University Munich, Munich, Germany
| | - Lioba Huelsboemer
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
| | - Leonard Knoedler
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
| | - Viola A. Stögner
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
| | - Bohdan Pomahac
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
| | - Martin Kauke-Navarro
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
- Correspondence: Samuel Knoedler Martin Kauke-Navarro
| | - David Colen
- Department of Surgery, Division of Plastic Surgery, Yale School of Medicine, Yale New Haven Hospital,New Haven, CT, United States
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Hyperspectral Imaging Allows Evaluation of Free Flaps in Craniomaxillofacial Reconstruction. J Craniofac Surg 2022; 34:e212-e216. [PMID: 36168125 DOI: 10.1097/scs.0000000000009009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 08/12/2022] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Treatment of extended defects after tumor resection in oral, maxillofacial, and facial surgery (craniomaxillofacial) is usually performed by free microvascular flaps. Evaluation of flap survival is crucial, especially in the first hours after insertion and connection. For flap evaluation various invasive and noninvasive methods have been developed. This retrospective clinical study examined the ability of a hyperspectral imaging (HSI) camera (Tivita, Diaspective Vision, Germany) to assess postoperative flap properties in comparison to established clinical parameters. MATERIALS AND METHODS Thirteen patients with tumor resection and free flap reconstruction were included for camera analysis and another 10 patients as control group. For this purpose, at defined time intervals and under standardized conditions, recordings of transplants 3 to 100 hours postoperatively were performed. Images were used to examine oxygenation (StO2%), tissue hemoglobin index, tissue water index, near infrared range perfusion index of free flaps quantitatively and qualitatively. RESULTS HSI provides values differing between patients observed with no intraindividual significant difference. After 24 hours a mean reduction of 16.77% for StO2%, 9.16% for tissue hemoglobin index and 8.46% was observed, going in line with no loss of flap was noted in the observation period. CONCLUSION HSI is suitable as a noninvasive measure for the evaluation of free flaps in craniomaxillofacial surgery in case of stable imaging conditions with respect to light, surrounding and position of the camera. However, clinical measurements are still the method of choice.
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Becker P, Blatt S, Pabst A, Heimes D, Al-Nawas B, Kämmerer PW, Thiem DGE. Comparison of Hyperspectral Imaging and Microvascular Doppler for Perfusion Monitoring of Free Flaps in an In Vivo Rodent Model. J Clin Med 2022; 11:jcm11144134. [PMID: 35887901 PMCID: PMC9321983 DOI: 10.3390/jcm11144134] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 01/27/2023] Open
Abstract
To reduce microvascular free flap failure (MFF), monitoring is crucial for the early detection of malperfusion and allows timely salvage. Therefore, the aim of this study was to evaluate hyperspectral imaging (HSI) in comparison to micro-Doppler sonography (MDS) to monitor MFF perfusion in an in vivo rodent model. Bilateral groin flaps were raised on 20 Sprague−Dawley rats. The femoral artery was transected on the trial side and re-anastomosed. Flaps and anastomoses were assessed before, during, and after the period of ischemia every ten minutes for overall 60 min using HSI and MDS. The contralateral sides’ flaps served as controls. Tissue-oxygenation saturation (StO2), near-infrared perfusion index (NPI), hemoglobin (THI), and water distribution (TWI) were assessed by HSI, while blood flow was assessed by MDS. HSI correlates with the MDS signal in the case of sufficient and completely interrupted perfusion. HSI was able to validly and reproducibly detect tissue perfusion status using StO2 and NPI. After 40 min, flap perfusion decreased due to the general aggravation of hemodynamic circulatory situation, which resulted in a significant drop of StO2 (p < 0.005) and NPI (p < 0.005), whereas the Doppler signal remained unchanged. In accordance, HSI might be suitable to detect MFF general complications in an early stage and further decrease MFF failure rates, whereas MDS may only be used for direct complications at the anastomose site.
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Affiliation(s)
- Philipp Becker
- Department of Oral and Maxillofacial Surgery, Federal Armed Forces Hospital, Rübenacherstr. 170, 56072 Koblenz, Germany;
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
- Correspondence:
| | - Sebastian Blatt
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Andreas Pabst
- Department of Oral and Maxillofacial Surgery, Federal Armed Forces Hospital, Rübenacherstr. 170, 56072 Koblenz, Germany;
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Diana Heimes
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Bilal Al-Nawas
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Peer W. Kämmerer
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
| | - Daniel G. E. Thiem
- Department of Oral and Maxillofacial Surgery, University Medical Centre Mainz, 55131 Mainz, Germany; (S.B.); (D.H.); (B.A.-N.); (P.W.K.); (D.G.E.T.)
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Long-Term Donor Site Morbidity and Flap Perfusion Following Radial versus Ulnar Forearm Free Flap—A Randomized Controlled Prospective Clinical Trial. J Clin Med 2022; 11:jcm11133601. [PMID: 35806884 PMCID: PMC9267742 DOI: 10.3390/jcm11133601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/19/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022] Open
Abstract
This clinical prospective randomized controlled study aimed to investigate the differences between Radial (RFFF) and Ulnar (UFFF) Forearm Free Flap in terms of success, performance, and donor site morbidity. Thirty patients with reconstruction of the head and neck region were included. For the first time, this study assessed flap-perfusion characteristics, donor-site-wound-healing dynamics and hand perfusion using hyperspectral imaging. Further, subjective (Likert-scale, DASH-score) and objective (grip/pinch-strength) parameters of donor site morbidity were analysed. Postoperative follow-up was performed until 6 months after index surgery. With 100% of patients, RFFF and UFFF were equally successful. Compared to surrounding reference, UFFF revealed significant lower tissue oxygenation saturation (StO2) than RFFF. Compared with UFFF, blood flow in both the thenar and hypothenar region were significantly reduced 6 months following RFFF transfer. After four weeks, 27% more patients demonstrated impaired wound healing following RFFF transfer. After 6 months, epithelial-surface continuity was restored in all patients of both groups. After 6 months, overall rates of both subjective and objective donor site morbidity were comparable between RFFF and UFFF. RFFF and UFFF both demonstrate similar success rates and HSI-perfusion dynamics following transfer. After 4 weeks, wound-healing disorder appeared significantly more often in RFFF than in UFFF; however, they became equal after 6 months. RFFF and UFFF can be considered as mutual alternatives.
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21
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Evaluation of Hyperspectral Imaging for Follow-Up Assessment after Revascularization in Peripheral Artery Disease. J Clin Med 2022; 11:jcm11030758. [PMID: 35160210 PMCID: PMC8836513 DOI: 10.3390/jcm11030758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 12/14/2022] Open
Abstract
Background: Assessment of tissue oxygenation is an important aspect of detection and monitoring of patients with peripheral artery disease (PAD). Hyperspectral imaging (HSI) is a non-contact technology for assessing microcirculatory function by quantifying tissue oxygen saturation (StO2). This study investigated whether HSI can be used to monitor skin oxygenation in patients with PAD after appropriate treatment of the lower extremities. Methods: For this purpose, 37 patients with PAD were studied by means of ankle–brachial index (ABI) and HSI before and after surgical or endovascular therapy. Thereby, the oxygenation parameter StO2 and near infrared (NIR) perfusion index were quantified in seven angiosomes on the diseased lower leg and foot. In addition, the effects of skin temperature and physical activity on StO2 and the NIR perfusion index and the respective inter-operator variability of these parameters were investigated in 25 healthy volunteers. Results: In all patients, the ABI significantly increased after surgical and endovascular therapy. In parallel, HSI revealed significant changes in both StO2 and NIR perfusion index in almost all studied angiosomes depending on the performed treatment. The increase in tissue oxygenation saturation was especially pronounced after surgical treatment. Neither heat nor cold, nor physical activity, nor repeated assessments of HSI parameters by independent investigators significantly affected the results on StO2 and the NIR perfusion index. Conclusions: Tissue oxygen saturation data obtained with HSI are robust to external confounders, such as temperature and physical activity, and do not show inter-operator variability; therefore, can be used as an additional technique to established methods, such as the ABI, to monitor peripheral perfusion in patients with PAD.
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Knitschke M, Baumgart AK, Bäcker C, Adelung C, Roller F, Schmermund D, Böttger S, Streckbein P, Howaldt HP, Attia S. Impact of Periosteal Branches and Septo-Cutaneous Perforators on Free Fibula Flap Outcome: A Retrospective Analysis of Computed Tomography Angiography Scans in Virtual Surgical Planning. Front Oncol 2022; 11:821851. [PMID: 35127535 PMCID: PMC8807634 DOI: 10.3389/fonc.2021.821851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Virtual surgical planning (VSP) for jaw reconstruction with free fibula flap (FFF) became a routine procedure and requires computed tomography angiography (CTA) for preoperative evaluation of the lower limbs vascular system and the bone. The aim of the study was to assess whether the distribution and density of periosteal branches (PB) and septo-cutaneous perforators (SCP) of the fibular artery have an impact on flap success. METHOD This retrospective clinical study assessed preoperative CTA of the infra-popliteal vasculature and the small vessel system of 72 patients who underwent FFF surgery. Surgical outcome of flap transfer includes wound healing, subtotal, and total flap loss were matched with the segmental vascular supply. RESULT A total of 72 patients (28 females, 38.9 %; 44 males, 61.1 %) fulfilled the study inclusion criteria. The mean age was 58.5 (± 15.3 years). Stenoses of the lower limbs' vessel (n = 14) were mostly detected in the fibular artery (n = 11). Flap success was recorded in n = 59 (82.0%), partial flap failure in n = 4 (5.5%) and total flap loss in n = 9 (12.5%). The study found a mean number (± SD) of 2.53 ± 1.60 PBs and 1.39 ± 1.03 SCPs of the FA at the donor-site. The proximal FFF segment of poly-segmental jaw reconstruction showed a higher rate of PB per flap segment than in the distal segments. Based on the total number of prepared segments (n = 121), 46.7% (n = 7) of mono-, 40.4% (n = 21) of bi-, and 31.5 % (n = 17) of tri-segmental fibula flaps were at least supplied by one PB in the success group. Overall, this corresponds to 37.2% (45 out of 121) of all successful FFF. For total flap loss (n = 14), a relative number of 42.9% (n = 6) of distinct supplied segments was recorded. Wound healing disorder of the donor site was not statistically significant influenced by the detected rate of SCP. CONCLUSION In general, a correlation between higher rates of PB and SCP and the flap success could not be statistically proved by the study sample. We conclude, that preoperative PB and SCP mapping based on routine CTA imaging is not suitable for prediction of flap outcome.
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Affiliation(s)
- Michael Knitschke
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Anna Katrin Baumgart
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Christina Bäcker
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Christian Adelung
- Department of Diagnostic and Interventional Radiology and Pediatric Radiology, Justus-Liebig-University, Giessen, Germany
| | - Fritz Roller
- Department of Diagnostic and Interventional Radiology and Pediatric Radiology, Justus-Liebig-University, Giessen, Germany
| | - Daniel Schmermund
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Sebastian Böttger
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Philipp Streckbein
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Hans-Peter Howaldt
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
| | - Sameh Attia
- Department of Oral and Maxillofacial Surgery, Justus-Liebig-University, Giessen, Germany
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Pruimboom T, Lindelauf AAMA, Felli E, Sawor JH, Deliaert AEK, van der Hulst RRWJ, Al-Taher M, Diana M, Schols RM. Perioperative Hyperspectral Imaging to Assess Mastectomy Skin Flap and DIEP Flap Perfusion in Immediate Autologous Breast Reconstruction: A Pilot Study. Diagnostics (Basel) 2022; 12:diagnostics12010184. [PMID: 35054352 PMCID: PMC8774932 DOI: 10.3390/diagnostics12010184] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/03/2022] [Accepted: 01/10/2022] [Indexed: 12/10/2022] Open
Abstract
Mastectomy skin flap necrosis (MSFN) and partial DIEP (deep inferior epigastric artery perforator) flap loss represent two frequently reported complications in immediate autologous breast reconstruction. These complications could be prevented when areas of insufficient tissue perfusion are detected intraoperatively. Hyperspectral imaging (HSI) is a relatively novel, non-invasive imaging technique, which could be used to objectively assess tissue perfusion through analysis of tissue oxygenation patterns (StO2%), near-infrared (NIR%), tissue hemoglobin (THI%), and tissue water (TWI%) perfusion indices. This prospective clinical pilot study aimed to evaluate the efficacy of HSI for tissue perfusion assessment and to identify a cut-off value for flap necrosis. Ten patients with a mean age of 55.4 years underwent immediate unilateral autologous breast reconstruction. Prior, during and up to 72 h after surgery, a total of 19 hyperspectral images per patient were acquired. MSFN was observed in 3 out of 10 patients. No DIEP flap necrosis was observed. In all MSFN cases, an increased THI% and decreased StO2%, NIR%, and TWI% were observed when compared to the vital group. StO2% was found to be the most sensitive parameter to detect MSFN with a statistically significant lower mean StO2% (51% in the vital group versus 32% in the necrosis group, p < 0.0001) and a cut-off value of 36.29% for flap necrosis. HSI has the potential to accurately assess mastectomy skin flap perfusion and discriminate between vital and necrotic skin flap during the early postoperative period prior to clinical observation. Although the results should be confirmed in future studies, including DIEP flap necrosis specifically, these findings suggest that HSI can aid clinicians in postoperative mastectomy skin flap and DIEP flap monitoring.
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Affiliation(s)
- Tim Pruimboom
- Department of Plastic, Reconstructive and Hand Surgery, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands;
- Correspondence: (T.P.); (R.M.S.); Tel.: +31-(0)43-3877481 (T.P. & R.M.S.)
| | - Anouk A. M. A. Lindelauf
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands;
| | - Eric Felli
- Department of Visceral Surgery and Medicine, University of Bern, 3010 Bern, Switzerland;
- Department of Biomedical Research, Hepatology, University of Bern, 3012 Bern, Switzerland
| | - John H. Sawor
- Department of Plastic, Reconstructive, and Hand Surgery, VieCuri Medical Center, 5912 BL Venlo, The Netherlands; (J.H.S.); (A.E.K.D.)
| | - An E. K. Deliaert
- Department of Plastic, Reconstructive, and Hand Surgery, VieCuri Medical Center, 5912 BL Venlo, The Netherlands; (J.H.S.); (A.E.K.D.)
| | - René R. W. J. van der Hulst
- Department of Plastic, Reconstructive and Hand Surgery, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands;
| | - Mahdi Al-Taher
- Department of Surgery, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands;
- Research Institute Against Digestive Cancer (IRCAD), 67000 Strasbourg, France;
| | - Michele Diana
- Research Institute Against Digestive Cancer (IRCAD), 67000 Strasbourg, France;
- Department of General, Digestive and Endocrine Surgery, University Hospital of Strasbourg, 67200 Strasbourg, France
- ICube Lab, Photonics for Health, University of Strasbourg, 67400 Strasbourg, France
| | - Rutger M. Schols
- Department of Plastic, Reconstructive and Hand Surgery, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands;
- Correspondence: (T.P.); (R.M.S.); Tel.: +31-(0)43-3877481 (T.P. & R.M.S.)
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24
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Lindelauf AAMA, Saelmans AG, van Kuijk SMJ, van der Hulst RRWJ, Schols RM. Near-Infrared Spectroscopy (NIRS) versus Hyperspectral Imaging (HSI) to Detect Flap Failure in Reconstructive Surgery: A Systematic Review. LIFE (BASEL, SWITZERLAND) 2022; 12:life12010065. [PMID: 35054458 PMCID: PMC8778121 DOI: 10.3390/life12010065] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 12/24/2021] [Accepted: 12/31/2021] [Indexed: 12/28/2022]
Abstract
Rapid identification of possible vascular compromise in free flap reconstruction to minimize time to reoperation improves achieving free flap salvage. Subjective clinical assessment, often complemented with handheld Doppler, is the golden standard for flap monitoring; but this lacks consistency and may be variable. Non-invasive optical methods such as near-infrared spectroscopy (NIRS) and hyperspectral imaging (HSI) could facilitate objective flap monitoring. A systematic review was conducted to compare NIRS with HSI in detecting vascular compromise in reconstructive flap surgery as compared to standard monitoring. A literature search was performed using PubMed and Embase scientific database in August 2021. Studies were selected by two independent reviewers. Sixteen NIRS and five HSI studies were included. In total, 3662 flap procedures were carried out in 1970 patients using NIRS. Simultaneously; 90 flaps were performed in 90 patients using HSI. HSI and NIRS flap survival were 92.5% (95% CI: 83.3–96.8) and 99.2% (95% CI: 97.8–99.7). Statistically significant differences were observed in flap survival (p = 0.02); flaps returned to OR (p = 0.04); salvage rate (p < 0.01) and partial flap loss rate (p < 0.01). However, no statistically significant difference was observed concerning flaps with vascular crisis (p = 0.39). NIRS and HSI have proven to be reliable; accurate and user-friendly monitoring methods. However, based on the currently available literature, no firm conclusions can be drawn concerning non-invasive monitoring technique superiority
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Affiliation(s)
- Anouk A. M. A. Lindelauf
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands;
- Correspondence: (A.A.M.A.L.); (R.M.S.); Tel.: +31-433875318 (A.A.M.A.L.); Fax: +31-433875075 (A.A.M.A.L.)
| | - Alexander G. Saelmans
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands;
- Department of Plastic, Reconstructive and Hand Surgery, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands;
| | - Sander M. J. van Kuijk
- Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands;
| | - René R. W. J. van der Hulst
- Department of Plastic, Reconstructive and Hand Surgery, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands;
| | - Rutger M. Schols
- Department of Plastic, Reconstructive and Hand Surgery, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands;
- Correspondence: (A.A.M.A.L.); (R.M.S.); Tel.: +31-433875318 (A.A.M.A.L.); Fax: +31-433875075 (A.A.M.A.L.)
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Dietrich M, Özdemir B, Gruneberg D, Petersen C, Studier-Fischer A, von der Forst M, Schmitt FCF, Fiedler MO, Nickel F, Müller-Stich BP, Brenner T, Weigand MA, Uhle F, Schmidt K. Hyperspectral Imaging for the Evaluation of Microcirculatory Tissue Oxygenation and Perfusion Quality in Haemorrhagic Shock: A Porcine Study. Biomedicines 2021; 9:1829. [PMID: 34944645 PMCID: PMC8698916 DOI: 10.3390/biomedicines9121829] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The ultimate goal of haemodynamic therapy is to improve microcirculatory tissue and organ perfusion. Hyperspectral imaging (HSI) has the potential to enable noninvasive microcirculatory monitoring at bedside. METHODS HSI (Tivita® Tissue System) measurements of tissue oxygenation, haemoglobin, and water content in the skin (ear) and kidney were evaluated in a double-hit porcine model of major abdominal surgery and haemorrhagic shock. Animals of the control group (n = 7) did not receive any resuscitation regime. The interventional groups were treated exclusively with either crystalloid (n = 8) or continuous norepinephrine infusion (n = 7). RESULTS Haemorrhagic shock led to a drop in tissue oxygenation parameters in all groups. These correlated with established indirect markers of tissue oxygenation. Fluid therapy restored tissue oxygenation parameters. Skin and kidney measurements correlated well. High dose norepinephrine therapy deteriorated tissue oxygenation. Tissue water content increased both in the skin and the kidney in response to fluid therapy. CONCLUSIONS HSI detected dynamic changes in tissue oxygenation and perfusion quality during shock and was able to indicate resuscitation effectivity. The observed correlation between HSI skin and kidney measurements may offer an estimation of organ oxygenation impairment from skin monitoring. HSI microcirculatory monitoring could open up new opportunities for the guidance of haemodynamic management.
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Affiliation(s)
- Maximilian Dietrich
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Berkin Özdemir
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany; (B.Ö.); (A.S.-F.); (F.N.); (B.P.M.-S.)
| | - Daniel Gruneberg
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Clara Petersen
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Alexander Studier-Fischer
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany; (B.Ö.); (A.S.-F.); (F.N.); (B.P.M.-S.)
| | - Maik von der Forst
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Felix C. F. Schmitt
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Mascha O. Fiedler
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Felix Nickel
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany; (B.Ö.); (A.S.-F.); (F.N.); (B.P.M.-S.)
| | - Beat Peter Müller-Stich
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany; (B.Ö.); (A.S.-F.); (F.N.); (B.P.M.-S.)
| | - Thorsten Brenner
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (T.B.); (K.S.)
| | - Markus A. Weigand
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Florian Uhle
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany; (D.G.); (C.P.); (M.v.d.F.); (F.C.F.S.); (M.O.F.); (M.A.W.); (F.U.)
| | - Karsten Schmidt
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (T.B.); (K.S.)
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Dietrich M, Marx S, von der Forst M, Bruckner T, Schmitt FCF, Fiedler MO, Nickel F, Studier-Fischer A, Müller-Stich BP, Hackert T, Brenner T, Weigand MA, Uhle F, Schmidt K. Hyperspectral imaging for perioperative monitoring of microcirculatory tissue oxygenation and tissue water content in pancreatic surgery - an observational clinical pilot study. Perioper Med (Lond) 2021; 10:42. [PMID: 34847953 PMCID: PMC8638177 DOI: 10.1186/s13741-021-00211-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 07/30/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hyperspectral imaging (HSI) could provide extended haemodynamic monitoring of perioperative tissue oxygenation and tissue water content to visualize effects of haemodynamic therapy and surgical trauma. The objective of this study was to assess the capacity of HSI to monitor skin microcirculation and possible relations to perioperative organ dysfunction in patients undergoing pancreatic surgery. METHODS The hyperspectral imaging TIVITA® Tissue System was used to evaluate superficial tissue oxygenation (StO2), deeper layer tissue oxygenation (near-infrared perfusion index (NPI)), haemoglobin distribution (tissue haemoglobin index (THI)) and tissue water content (tissue water index (TWI)) in 25 patients undergoing pancreatic surgery. HSI parameters were measured before induction of anaesthesia (t1), after induction of anaesthesia (t2), postoperatively before anaesthesia emergence (t3), 6 h after emergence of anaesthesia (t4) and three times daily (08:00, 14:00, 20:00 ± 1 h) at the palm and the fingertips until the second postoperative day (t5-t10). Primary outcome was the correlation of HSI with perioperative organ dysfunction assessed with the perioperative change of SOFA score. RESULTS Two hundred and fifty HSI measurements were performed in 25 patients. Anaesthetic induction led to a significant increase of tissue oxygenation parameters StO2 and NPI (t1-t2). StO2 and NPI decreased significantly from t2 until the end of surgery (t3). THI of the palm showed a strong correlation with haemoglobin levels preoperatively (t2: r = 0.83, p < 0.001) and 6 h postoperatively (t4: r = 0.71, p = 0.001) but not before anaesthesia emergence (t3: r = 0.35, p = 0.10). TWI of the palm and the fingertip rose significantly between pre- and postoperative measurements (t2-t3). Higher blood loss, syndecan level and duration of surgery were associated with a higher increase of TWI. The perioperative change of HSI parameters (∆t1-t3) did not correlate with the perioperative change of the SOFA score. CONCLUSION This is the first study using HSI skin measurements to visualize tissue oxygenation and tissue water content in patients undergoing pancreatic surgery. HSI was able to measure short-term changes of tissue oxygenation during anaesthetic induction and pre- to postoperatively. TWI indicated a perioperative increase of tissue water content. Perioperative use of HSI could be a useful extension of haemodynamic monitoring to assess the microcirculatory response during haemodynamic therapy and major surgery. TRIAL REGISTRATION German Clinical Trial Register, DRKS00017313 on 5 June 2019.
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Affiliation(s)
- Maximilian Dietrich
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Sebastian Marx
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Maik von der Forst
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Bruckner
- Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany
| | - Felix C F Schmitt
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Mascha O Fiedler
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Felix Nickel
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Studier-Fischer
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Beat P Müller-Stich
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Thilo Hackert
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Thorsten Brenner
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Markus A Weigand
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Florian Uhle
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Karsten Schmidt
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
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Barberio M, Benedicenti S, Pizzicannella M, Felli E, Collins T, Jansen-Winkeln B, Marescaux J, Viola MG, Diana M. Intraoperative Guidance Using Hyperspectral Imaging: A Review for Surgeons. Diagnostics (Basel) 2021; 11:diagnostics11112066. [PMID: 34829413 PMCID: PMC8624094 DOI: 10.3390/diagnostics11112066] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 12/12/2022] Open
Abstract
Hyperspectral imaging (HSI) is a novel optical imaging modality, which has recently found diverse applications in the medical field. HSI is a hybrid imaging modality, combining a digital photographic camera with a spectrographic unit, and it allows for a contactless and non-destructive biochemical analysis of living tissue. HSI provides quantitative and qualitative information of the tissue composition at molecular level in a contrast-free manner, hence making it possible to objectively discriminate between different tissue types and between healthy and pathological tissue. Over the last two decades, HSI has been increasingly used in the medical field, and only recently it has found an application in the operating room. In the last few years, several research groups have used this imaging modality as an intraoperative guidance tool within different surgical disciplines. Despite its great potential, HSI still remains far from being routinely used in the daily surgical practice, since it is still largely unknown to most of the surgical community. The aim of this study is to provide clinical surgeons with an overview of the capabilities, current limitations, and future directions of HSI for intraoperative guidance.
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Affiliation(s)
- Manuel Barberio
- Institute for Research against Digestive Cancer (IRCAD), 67091 Strasbourg, France; (T.C.); (J.M.); (M.D.)
- General Surgery Department, Ospedale Card. G. Panico, 73039 Tricase, Italy; (S.B.); (M.P.); (M.G.V.)
- Correspondence:
| | - Sara Benedicenti
- General Surgery Department, Ospedale Card. G. Panico, 73039 Tricase, Italy; (S.B.); (M.P.); (M.G.V.)
| | - Margherita Pizzicannella
- General Surgery Department, Ospedale Card. G. Panico, 73039 Tricase, Italy; (S.B.); (M.P.); (M.G.V.)
| | - Eric Felli
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, 3008 Bern, Switzerland;
- Department for BioMedical Research, Visceral Surgery and Medicine, University of Bern, 3008 Bern, Switzerland
| | - Toby Collins
- Institute for Research against Digestive Cancer (IRCAD), 67091 Strasbourg, France; (T.C.); (J.M.); (M.D.)
| | | | - Jacques Marescaux
- Institute for Research against Digestive Cancer (IRCAD), 67091 Strasbourg, France; (T.C.); (J.M.); (M.D.)
| | - Massimo Giuseppe Viola
- General Surgery Department, Ospedale Card. G. Panico, 73039 Tricase, Italy; (S.B.); (M.P.); (M.G.V.)
| | - Michele Diana
- Institute for Research against Digestive Cancer (IRCAD), 67091 Strasbourg, France; (T.C.); (J.M.); (M.D.)
- ICube Laboratory, Photonics Instrumentation for Health, University of Strasbourg, 67400 Strasbourg, France
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New Approach to the Old Challenge of Free Flap Monitoring-Hyperspectral Imaging Outperforms Clinical Assessment by Earlier Detection of Perfusion Failure. J Pers Med 2021; 11:jpm11111101. [PMID: 34834453 PMCID: PMC8625540 DOI: 10.3390/jpm11111101] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 01/18/2023] Open
Abstract
In reconstructive surgery, free flap failure, especially in complex osteocutaneous reconstructions, represents a significant clinical burden. Therefore, the aim of the presented study was to assess hyperspectral imaging (HSI) for monitoring of free flaps compared to clinical monitoring. In a prospective, non-randomized clinical study, patients with free flap reconstruction of the oro-maxillofacial-complex were included. Monitoring was assessed clinically and by using hyperspectral imaging (TIVITA™ Tissue-System, DiaspectiveVision GmbH, Pepelow, Germany) to determine tissue-oxygen-saturation [StO2], near-infrared-perfusion-index [NPI], distribution of haemoglobin [THI] and water [TWI], and variance to an adjacent reference area (Δreference). A total of 54 primary and 11 secondary reconstructions were performed including fasciocutaneous and osteocutaneous flaps. Re-exploration was performed in 19 cases. A total of seven complete flap failures occurred, resulting in a 63% salvage rate. Mean time from flap inset to decision making for re-exploration based on clinical assessment was 23.1 ± 21.9 vs. 18.2 ± 19.4 h by the appearance of hyperspectral criteria indicating impaired perfusion (StO2 ≤ 32% OR StO2Δreference > −38% OR NPI ≤ 32.9 OR NPIΔreference ≥ −13.4%) resulting in a difference of 4.8 ± 5 h (p < 0.001). HSI seems able to detect perfusion compromise significantly earlier than clinical monitoring. These findings provide an interpretation aid for clinicians to simplify postoperative flap monitoring.
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Nischwitz SP, Luze H, Schellnegger M, Gatterer SJ, Tuca AC, Winter R, Kamolz LP. Thermal, Hyperspectral, and Laser Doppler Imaging: Non-Invasive Tools for Detection of The Deep Inferior Epigastric Artery Perforators-A Prospective Comparison Study. J Pers Med 2021; 11:jpm11101005. [PMID: 34683146 PMCID: PMC8538291 DOI: 10.3390/jpm11101005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/02/2021] [Accepted: 10/04/2021] [Indexed: 11/16/2022] Open
Abstract
Perforator flaps have become one of the leading procedures in microsurgical tissue transfer. Individual defects require a tailored approach to guarantee the most effective treatment. A thorough understanding of the individual vascular anatomy and the location of prominent perforators is of utmost importance and usually requires invasive angiography or at least acoustic Doppler exploration. In this study, we aimed at evaluating different non-invasive imaging modalities as possible alternatives for perforator location detection. After a cooling phase, we performed thermal, hyperspectral and Laser Doppler imaging and visually evaluated a possible detection of the perforator for a period of five minutes with an image taken every minute. We identified the most prominent perforator of the deep inferior epigastric artery by handheld acoustic Doppler in 18 patients. The detected perforator locations were then correlated. Eighteen participants were assessed with six images each per imaging method. We could show a positive match for 94.44%, 38.89%, and 0% of patients and 92.59%, 25.93%, and 0% of images for the methods respectively compared to the handheld acoustic Doppler. Sex, age, abdominal girth, and BMI showed no correlation with a possible visual detection of the perforator in the images. Therefore, thermal imaging can yield valuable supporting data in the individualized procedure planning. Future larger cohort studies are required to better assess the full potential of modern handheld thermal imaging devices.
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Affiliation(s)
- Sebastian P. Nischwitz
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, 8036 Graz, Austria; (H.L.); (A.-C.T.); (R.W.); (L.-P.K.)
- COREMED—Cooperative Centre for Regenerative Medicine, JOANNEUM RESEARCH Forschungsgesellschaft mbH, 8010 Graz, Austria;
- Correspondence:
| | - Hanna Luze
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, 8036 Graz, Austria; (H.L.); (A.-C.T.); (R.W.); (L.-P.K.)
- COREMED—Cooperative Centre for Regenerative Medicine, JOANNEUM RESEARCH Forschungsgesellschaft mbH, 8010 Graz, Austria;
| | - Marlies Schellnegger
- COREMED—Cooperative Centre for Regenerative Medicine, JOANNEUM RESEARCH Forschungsgesellschaft mbH, 8010 Graz, Austria;
- Division of Macroscopic and Clinical Anatomy, Medical University of Graz, 8036 Graz, Austria
| | | | - Alexandru-Cristian Tuca
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, 8036 Graz, Austria; (H.L.); (A.-C.T.); (R.W.); (L.-P.K.)
| | - Raimund Winter
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, 8036 Graz, Austria; (H.L.); (A.-C.T.); (R.W.); (L.-P.K.)
| | - Lars-Peter Kamolz
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, 8036 Graz, Austria; (H.L.); (A.-C.T.); (R.W.); (L.-P.K.)
- COREMED—Cooperative Centre for Regenerative Medicine, JOANNEUM RESEARCH Forschungsgesellschaft mbH, 8010 Graz, Austria;
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Linek M, Felicio-Briegel A, Freymüller C, Rühm A, Englhard AS, Sroka R, Volgger V. Evaluation of hyperspectral imaging to quantify perfusion changes during the modified Allen test. Lasers Surg Med 2021; 54:245-255. [PMID: 34541694 DOI: 10.1002/lsm.23479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/29/2021] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To evaluate the capability of hyperspectral imaging (HSI), a contact-less and noninvasive technology, to monitor perfusion changes of the hand during a modified Allen test (MAT) and cuff occlusion test. Furthermore, the study aimed at obtaining objective perfusion parameters of the hand. METHODS HSI of the hand was performed on 20 healthy volunteers with a commercially available HSI system during a MAT and a cuff occlusion test. Besides gathering red-green-blue (RGB) images, the perfusion parameters tissue hemoglobin index (THI), (superficial tissue) hemoglobin oxygenation (StO2), near-infrared perfusion (NIR), and tissue water index (TWI) were calculated for four different regions of interest on the hand. For the MAT, occlusion (OI; the ratio between the condition during occlusion and before occlusion) and reperfusion (RI; the ratio between the non-occlusion state and the prior occlusion state) indices were calculated for each perfusion parameter. All data were correlated to the clinical findings. RESULTS False-color images showed visible differences between the various perfusion conditions during the MAT and cuff occlusion test. THI, StO2, and NIR behaved as expected from physiology, while TWI did not in the context of this study. During rest, mean THI, StO2, and NIR of the hand were 34 ± 2, 72 ± 9, and 61 ± 6, respectively. The RI for THI showed a roundabout threefold increase after reperfusion of both radial and ulnar artery and was thus, distinctly pronounced when compared with StO2 and NIR (~1.25). The OI was lowest for THI when compared with StO2 and NIR. CONCLUSIONS HSI with its parameters THI, StO2, and NIR proved to be suitable to evaluate perfusion of the hand. By this, it could complement visual inspection during the MAT for evaluating the functionality of the superficial palmary arch before radial or ulnar artery harvest. The presented RI might deliver useful comparative values to detect pathological perfusion disorders at an early stage. As microcirculation monitoring is crucial for many medical issues, HSI shows potential to be used, besides further applications, in the monitoring of (free) flaps and transplants and microcirculation monitoring of critically ill patients.
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Affiliation(s)
- Matthäus Linek
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
| | | | - Christian Freymüller
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
| | - Adrian Rühm
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Anna Sophie Englhard
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
| | - Ronald Sroka
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Veronika Volgger
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
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Thiem DGE, Römer P, Gielisch M, Al-Nawas B, Schlüter M, Plaß B, Kämmerer PW. Hyperspectral imaging and artificial intelligence to detect oral malignancy - part 1 - automated tissue classification of oral muscle, fat and mucosa using a light-weight 6-layer deep neural network. Head Face Med 2021; 17:38. [PMID: 34479595 PMCID: PMC8414848 DOI: 10.1186/s13005-021-00292-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 08/25/2021] [Indexed: 01/17/2023] Open
Abstract
Background Hyperspectral imaging (HSI) is a promising non-contact approach to tissue diagnostics, generating large amounts of raw data for whose processing computer vision (i.e. deep learning) is particularly suitable. Aim of this proof of principle study was the classification of hyperspectral (HS)-reflectance values into the human-oral tissue types fat, muscle and mucosa using deep learning methods. Furthermore, the tissue-specific hyperspectral signatures collected will serve as a representative reference for the future assessment of oral pathological changes in the sense of a HS-library. Methods A total of about 316 samples of healthy human-oral fat, muscle and oral mucosa was collected from 174 different patients and imaged using a HS-camera, covering the wavelength range from 500 nm to 1000 nm. HS-raw data were further labelled and processed for tissue classification using a light-weight 6-layer deep neural network (DNN). Results The reflectance values differed significantly (p < .001) for fat, muscle and oral mucosa at almost all wavelengths, with the signature of muscle differing the most. The deep neural network distinguished tissue types with an accuracy of > 80% each. Conclusion Oral fat, muscle and mucosa can be classified sufficiently and automatically by their specific HS-signature using a deep learning approach. Early detection of premalignant-mucosal-lesions using hyperspectral imaging and deep learning is so far represented rarely in in medical and computer vision research domain but has a high potential and is part of subsequent studies. Supplementary Information The online version contains supplementary material available at 10.1186/s13005-021-00292-0.
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Affiliation(s)
- Daniel G E Thiem
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre Mainz, Augustusplatz 2, 55131, Mainz, Germany.
| | - Paul Römer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - Matthias Gielisch
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - Bilal Al-Nawas
- International Scholar and Adjunct Associate Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyung Hee University, Seoul, South Korea
| | - Martin Schlüter
- School of Technology - Geoinformatics and Surveying, Institute for Spatial Information and Surveying Technology, University of Mainz - University of Applied Science, Mainz, Germany
| | - Bastian Plaß
- School of Technology - Geoinformatics and Surveying, Institute for Spatial Information and Surveying Technology, University of Mainz - University of Applied Science, Mainz, Germany
| | - Peer W Kämmerer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Centre Mainz, Augustusplatz 2, 55131, Mainz, Germany
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Hyperspectral Imaging to Study Dynamic Skin Perfusion after Injection of Articaine-4% with and without Epinephrine-Clinical Implications on Local Vasoconstriction. J Clin Med 2021; 10:jcm10153411. [PMID: 34362194 PMCID: PMC8347280 DOI: 10.3390/jcm10153411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/20/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022] Open
Abstract
This study aimed to investigate the dynamic skin perfusion via hyperspectral imaging (HSI) after application of Articaine-4% ± epinephrine as well as epinephrine only. After the subcutaneous injection of (A100) Articaine-4% with epinephrine 1:100,000, (A200) Articaine-4% with epinephrine 1:200,000, (Aw/o) Articaine-4% without epinephrine, and (EPI200) epinephrine 1:200,000, into the flexor side of the forearm in a split-arm design, dynamic skin perfusion measurement was performed over 120 min by determining tissue oxygen saturation (StO2) using HSI. After injection, all groups experienced a reactive hyperaemia. With A200, it took about three min for StO2 to drop below baseline. For Aw/o and EPI200, perfusion reduction when compared to baseline was seen at 30 min with vasoconstriction >120 min. A100 caused vasodilation with hyperaemia >60 min. After three minutes, the perfusion pattern differed significantly (p < 0.001) between all groups except Aw/o and EPI200. The vasoactive effect of epinephrine-containing local anaesthetics can be visualised and dynamically quantified via StO2 using HSI. Aw/o + epinephrine 1:100,000 and 1:200,000 leads to perfusion reduction and tissue ischaemia after 30 min, which lasts over 120 min with no significant difference between both formulations. When using Aw/o containing epinephrine in terms of haemostasis for surgical procedures, a prolonged waiting time before incision of 30 or more min can be recommended.
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Lee S, Namgoong JM, Kim Y, Cha J, Kim JK. Multimodal imaging of laser speckle contrast imaging combined with mosaic filter-based hyperspectral imaging for precise surgical guidance. IEEE Trans Biomed Eng 2021; 69:443-452. [PMID: 34260344 DOI: 10.1109/tbme.2021.3097122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To enable a real-time surgical guidance system that simultaneously monitors blood vessel perfusion, oxygen saturation, thrombosis, and tissue recovery by combining multiple optical imaging techniques into a single system: visible imaging, mosaic filter-based snapshot hyperspectral imaging (HSI), and laser speckle contrast imaging (LSCI). METHODS The multimodal optical imaging system was demonstrated by clamping blood vessels in the small intestines of rats to create areas of restricted blood flow. Subsequent tissue damage and regeneration were monitored during procedures. Using LSCI, vessel perfusion was measured, revealing the biological activity and survival of organ tissues. Blood oxygen saturation was monitored using HSI in the near-infrared region. Principal component analysis was used over the spectral dimension to identify an HSI wavelength combination optimized for hemodynamic biomarker visualization. HSI and LSCI were complimentary, identifying thrombus generation and tissue recovery, which was not possible in either modality alone. RESULTS AND CONCLUSION By analyzing multimodal tissue information from visible imaging, LSCI perfusion imaging, and HSI, a recovery prognosis could be determined based on the blood supply to the organ. The unique combination of the complementary imaging techniques into a single surgical microscope holds promise for improving the real-time determination of blood supply and tissue prognosis during surgery. SIGNIFICANCE Precise real-time monitoring for vascular anomalies promises to reduce the risk of organ damage in precise surgical operations such as tissue resection and transplantation. In addition, the convergence of label-free imaging technologies removes delays associated with the injection and diffusion of vascular monitoring dyes.
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Is Hyperspectral Imaging Suitable for Assessing Collateral Circulation Prior Radial Forearm Free Flap Harvesting? Comparison of Hyperspectral Imaging and Conventional Allen's Test. J Pers Med 2021; 11:jpm11060531. [PMID: 34207631 PMCID: PMC8226690 DOI: 10.3390/jpm11060531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
(1) Background: This cross-sectional study aims to compare a new and non-invasive approach using hyperspectral imaging (HSI) with the conventional modified Allen’s test (MAT) for the assessment of collateral perfusion prior to radial forearm free flap harvest in healthy adults. (2) HSI of the right hand of 114 patients was recorded. Here, three recordings were carried out: (I) basic status (perfusion), (II) after occlusion of ulnar and radial artery (occlusion) and (III) after releasing the ulnar artery (reperfusion). At all recordings, tissue oxygenation/superficial perfusion (StO2 (0–100%); 0–1 mm depth), tissue hemoglobin index (THI (0–100)) and near infrared perfusion index/deep perfusion (NIR (0–100); 0–4 mm depth) were assessed. A modified Allen’s test (control) was conducted and compared with the HSI-results. (3) Results: Statistically significant differences between perfusion (I) and artery occlusion (II) and between artery occlusion (II) and reperfusion (III) could be observed within the population with a non-pathological MAT (each <0.001). Significant correlations were observed for the difference between perfusion and reperfusion in THI and the height of the MAT (p < 0.05). Within the population with a MAT >8 s, an impairment in reperfusion was shown (each p < 0.05) and the difference between perfusion and reperfusion exhibited a strong correlation to the height of the MAT (each p < 0.01). (4) Conclusions: The results indicate a reliable differentiation between perfusion and occlusion by HSI. Therefore, HSI could be a useful tool for verification of the correct performance of the MAT as well as to confirm the final diagnosis, as it provides an objective, reproducible method whose results strongly correlate with those obtained by MAT. What is more, it can be easily applied by non-medical personnel.
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Dietrich M, Marx S, von der Forst M, Bruckner T, Schmitt FCF, Fiedler MO, Nickel F, Studier-Fischer A, Müller-Stich BP, Hackert T, Brenner T, Weigand MA, Uhle F, Schmidt K. Bedside hyperspectral imaging indicates a microcirculatory sepsis pattern - an observational study. Microvasc Res 2021; 136:104164. [PMID: 33831406 DOI: 10.1016/j.mvr.2021.104164] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/28/2021] [Accepted: 03/28/2021] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Microcirculatory alterations are key mechanisms in sepsis pathophysiology leading to tissue hypoxia, edema formation, and organ dysfunction. Hyperspectral imaging (HSI) is an emerging imaging technology that uses tissue-light interactions to evaluate biochemical tissue characteristics including tissue oxygenation, hemoglobin content and water content. Currently, clinical data for HSI technologies in critical ill patients are still limited. METHODS AND ANALYSIS TIVITA® Tissue System was used to measure Tissue oxygenation (StO2), Tissue Hemoglobin Index (THI), Near Infrared Perfusion Index (NPI) and Tissue Water Index (TWI) in 25 healthy volunteers and 25 septic patients. HSI measurement sites were the palm, the fingertip, and a suprapatellar knee area. Septic patients were evaluated on admission to the ICU (E), 6 h afterwards (E+6) and three times a day (t3-t9) within a total observation period of 72 h. Primary outcome was the correlation of HSI results with daily SOFA-scores. RESULTS Serial HSI at the three measurement sites in healthy volunteers showed a low mean variance expressing high retest reliability. HSI at E demonstrated significantly lower StO2 and NPI as well as higher TWI at the palm and fingertip in septic patients compared to healthy volunteers. StO2 and TWI showed corresponding results at the suprapatellar knee area. In septic patients, palm and fingertip THI identified survivors (E-t4) and revealed predictivity for 28-day mortality (E). Fingertip StO2 and THI correlated to SOFA-score on day 2. TWI was consistently increased in relation to the TWI range of healthy controls during the observation time. Palm TWI correlated positively with SOFA scores on day 3. DISCUSSION HSI results in septic patients point to a distinctive microcirculatory pattern indicative of reduced skin oxygenation and perfusion quality combined with increased blood pooling and tissue water content. THI might possess risk-stratification properties and TWI could allow tissue edema evaluation in critically ill patients. CONCLUSION HSI technologies could open new perspectives in microcirculatory monitoring by visualizing oxygenation and perfusion quality combined with tissue water content in critically ill patients - a prerequisite for future tissue perfusion guided therapy concepts in intensive care medicine.
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Affiliation(s)
- M Dietrich
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - S Marx
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - M von der Forst
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - T Bruckner
- Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany
| | - F C F Schmitt
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - M O Fiedler
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - F Nickel
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - A Studier-Fischer
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - B P Müller-Stich
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - T Hackert
- Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - T Brenner
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany; Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - M A Weigand
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - F Uhle
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - K Schmidt
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany; Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
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Schulz T, Leuschner S, Siemers F, Marotz J, Houschyar K, Corterier CC. Assessing flap perfusion after free tissue transfer using hyperspectral imaging (HSI). EUROPEAN JOURNAL OF PLASTIC SURGERY 2021. [DOI: 10.1007/s00238-021-01784-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Algorithm for Mapping Kidney Tissue Water Content during Normothermic Machine Perfusion Using Hyperspectral Imaging. ALGORITHMS 2020. [DOI: 10.3390/a13110289] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The preservation of kidneys using normothermic machine perfusion (NMP) prior to transplantation has the potential for predictive evaluation of organ quality. Investigations concerning the quantitative assessment of physiological tissue parameters and their dependence on organ function lack in this context. In this study, hyperspectral imaging (HSI) in the wavelength range of 500–995 nm was conducted for the determination of tissue water content (TWC) in kidneys. The quantitative relationship between spectral data and the reference TWC values was established by partial least squares regression (PLSR). Different preprocessing methods were applied to investigate their influence on predicting the TWC of kidneys. In the full wavelength range, the best models for absorbance and reflectance spectra provided Rp2 values of 0.968 and 0.963, as well as root-mean-square error of prediction (RMSEP) values of 2.016 and 2.155, respectively. Considering an optimal wavelength range (800–980 nm), the best model based on reflectance spectra (Rp2 value of 0.941, RMSEP value of 3.202). Finally, the visualization of TWC distribution in all pixels of kidneys’ HSI image was implemented. The results show the feasibility of HSI for a non-invasively and accurate TWC prediction in kidneys, which could be used in the future to assess the quality of kidneys during the preservation period.
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Kämmerer PW, Engel V, Plocksties F, Jonitz-Heincke A, Timmermann D, Engel N, Frerich B, Bader R, Thiem DGE, Skorska A, David R, Al-Nawas B, Dau M. Continuous Electrical Stimulation Affects Initial Growth and Proliferation of Adipose-Derived Stem Cells. Biomedicines 2020; 8:biomedicines8110482. [PMID: 33171654 PMCID: PMC7695310 DOI: 10.3390/biomedicines8110482] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 12/14/2022] Open
Abstract
The aim of the study was to establish electrical stimulation parameters in order to improve cell growth and viability of human adipose-derived stem cells (hADSC) when compared to non-stimulated cells in vitro. hADSC were exposed to continuous electrical stimulation with 1.7 V AC/20 Hz. After 24, 72 h and 7 days, cell number, cellular surface coverage and cell proliferation were assessed. In addition, cell cycle analysis was carried out after 3 and 7 days. After 24 h, no significant alterations were observed for stimulated cells. At day 3, stimulated cells showed a 4.5-fold increase in cell numbers, a 2.7-fold increase in cellular surface coverage and a significantly increased proliferation. Via cell cycle analysis, a significant increase in the G2/M phase was monitored for stimulated cells. Contrastingly, after 7 days, the non-stimulated group exhibited a 11-fold increase in cell numbers and a 4-fold increase in cellular surface coverage as well as a significant increase in cell proliferation. Moreover, the stimulated cells displayed a shift to the G1 and sub-G1 phase, indicating for metabolic arrest and apoptosis initiation. In accordance, continuous electrical stimulation of hADSC led to a significantly increased cell growth and proliferation after 3 days. However, longer stimulation periods such as 7 days caused an opposite result indicating initiation of apoptosis.
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Affiliation(s)
- Peer W. Kämmerer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Mainz, 55131 Mainz, Germany; (D.G.E.T.); (B.A.-N.)
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Rostock, 18057 Rostock, Germany; (V.E.); (N.E.); (B.F.); (M.D.)
- Correspondence: ; Tel.: +49-6131-17-3752
| | - Vivien Engel
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Rostock, 18057 Rostock, Germany; (V.E.); (N.E.); (B.F.); (M.D.)
| | - Franz Plocksties
- Institute of Applied Microelectronics and Computer Engineering, University of Rostock, 18051 Rostock, Germany; (F.P.); (D.T.)
| | - Anika Jonitz-Heincke
- Department of Orthopedics, University Medical Center Rostock, 18057 Rostock, Germany; (A.J.-H.); (R.B.)
| | - Dirk Timmermann
- Institute of Applied Microelectronics and Computer Engineering, University of Rostock, 18051 Rostock, Germany; (F.P.); (D.T.)
| | - Nadja Engel
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Rostock, 18057 Rostock, Germany; (V.E.); (N.E.); (B.F.); (M.D.)
| | - Bernhard Frerich
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Rostock, 18057 Rostock, Germany; (V.E.); (N.E.); (B.F.); (M.D.)
| | - Rainer Bader
- Department of Orthopedics, University Medical Center Rostock, 18057 Rostock, Germany; (A.J.-H.); (R.B.)
| | - Daniel G. E. Thiem
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Mainz, 55131 Mainz, Germany; (D.G.E.T.); (B.A.-N.)
| | - Anna Skorska
- Department of Cardiac Surgery, University Medical Center Rostock, 18059 Rostock, Germany; (A.S.); (R.D.)
- Department Life, Light & Matter (LL&M), University of Rostock, 18059 Rostock, Germany
| | - Robert David
- Department of Cardiac Surgery, University Medical Center Rostock, 18059 Rostock, Germany; (A.S.); (R.D.)
- Department Life, Light & Matter (LL&M), University of Rostock, 18059 Rostock, Germany
| | - Bilal Al-Nawas
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Mainz, 55131 Mainz, Germany; (D.G.E.T.); (B.A.-N.)
| | - Michael Dau
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University Medical Center Rostock, 18057 Rostock, Germany; (V.E.); (N.E.); (B.F.); (M.D.)
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Goetze E, Thiem DGE, Gielisch MW, Kämmerer PW. Identification of cutaneous perforators for microvascular surgery using hyperspectral technique - A feasibility study on the antero-lateral thigh. J Craniomaxillofac Surg 2020; 48:1066-1073. [PMID: 32994154 DOI: 10.1016/j.jcms.2020.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/11/2020] [Accepted: 09/07/2020] [Indexed: 12/11/2022] Open
Abstract
Aim of the study was to compare perforator vessel location using color-coded Doppler ultrasound and hyperspectral imaging in the area of the antero-lateral thigh. In a cross-sectional case-control study, the bilateral antero-lateral thigh region was examined for perforator vessel location via color-coded Doppler ultrasound (control) and hyperspectral imaging (test). For hyperspectral imaging, all measurements were conducted without cooling (T0) and after 1 (T1), 2 (T2) and 3 min (T3) of cooling. Additionally, in the reperfusion period after cooling, hyperspectral imaging was conducted at 1, 2 and 3 min (T4/T5/T6). Results from color-coded Doppler ultrasound and hyperspectral imaging were matched at all time points (T0-T6). In total, 71/73 perforator vessel locations could be matched (sensitivity: 97%). Matching of color-coded Doppler ultrasound and hyperspectral imaging was significantly influenced by the cooling protocol and the highest matching values were seen at T3 (3 min cooling; 60 perforator vessels) and T4 (3 min cooling & 1 min reperfusion; 62 perforator vessels) without significant differences (sensitivity 98%; p = 0.9). There were significant differences between T4 and T0, T1 (both p < 0.001), T5 (p = 0.045) and T6 (p = 0.012). For clinical proof of concept, a patient case using a free antero-lateral thigh flap for reconstruction of a facial defect after perforator vessel identification via color-coded Doppler ultrasound and hyperspectral imaging (3 min cooling & 1 min reperfusion) was carried out successfully. In conclusion, hyperspectral imaging potentially offers an additional opportunity for non-invasive, user-independent perforator-site assessment if prior cooling of the site is conducted.
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Affiliation(s)
- Elisabeth Goetze
- Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glueckstrasse 11, 91054, Erlangen, Germany; Department of Oral, Maxillofacial and Plastic Surgery, University Medical Center Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - Daniel G E Thiem
- Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glueckstrasse 11, 91054, Erlangen, Germany
| | - Matthias W Gielisch
- Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glueckstrasse 11, 91054, Erlangen, Germany
| | - Peer W Kämmerer
- Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glueckstrasse 11, 91054, Erlangen, Germany.
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