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Barnat N, Grisey A, Gerold B, Yon S, Anquez J, Aubry JF. Efficacy and safety assessment of an ultrasound-based thermal treatment of varicose veins in a sheep model. Int J Hyperthermia 2020; 37:231-244. [PMID: 32133898 DOI: 10.1080/02656736.2020.1734672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Purpose: Varicose veins are a common pathology that can be treated by endovenous thermal procedures like radiofrequency ablation (RFA). Such catheter-based techniques consist in raising the temperature of the vein wall to 70 to 120 °C to induce vein wall coagulation. Although effective, this treatment option is not suited for all types of veins and can be technically challenging.Materials and methods: In this study, we used High-Intensity Focused Ultrasound (HIFU) as a non-invasive thermal ablation procedure to treat varicose veins and we assessed the long-term efficacy and safety of the procedure in a sheep model. In vivo experiments were first conducted on two saphenous veins to measure the temperature rise induced at the vein wall during HIFU ablation and were compared with reported RFA-induced thermal rise. Thermocouples were inserted in situ to perform 20 measurements during 8-s ultrasound pulses at 3 MHz. Eighteen saphenous veins of nine anesthetized sheep (2-2.5 % Isoflurane) were then exposed to similar pulses (85 W acoustic, 8 s). After treatments, animals recovered from anesthesia and were followed up 30, 60 and 90 days post-treatment (n = 3 animals per group). At the end of the follow-up, vein segments and perivenous tissues were harvested and histologically examined.Results: Temperatures induced by HIFU pulses were found to be comparable to reported RFA treatments. Likewise, histological findings were similar to the ones reported after RFA and laser-based coagulation necrosis of the vein wall, thrombotic occlusions and vein wall fibrosis.Conclusion: These results support strongly the effectiveness and safety of HIFU for ablating non-invasively veins.
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Affiliation(s)
- Nesrine Barnat
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research University, Paris, France.,Theraclion, Malakoff, France
| | | | | | | | | | - Jean-François Aubry
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research University, Paris, France
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2
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Hazlewood D, Yang X. Enhanced cavitation activity in a slab-shaped optical absorber during photo-mediated ultrasound therapy. Phys Med Biol 2020; 65:055006. [PMID: 31715592 DOI: 10.1088/1361-6560/ab56f7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recently, new studies have shown that combined laser and ultrasound, or photo-mediated ultrasound therapy (PUT), can enhance cavitation in optically absorptive targets to disrupt tissues through photoacoustic (PA) effect. These studies, including both experimental and theoretical investigations, have largely focused on blood vessels, which are modeled as cylindrically-shaped optical absorbers for PA wave generation and propagation. However, in many clinical situations, target tissues may not be cylindrically-shaped. In this paper we investigated the effect of PUT on a slab-shaped optical absorber, much larger than the size of the laser beam or the ultrasound focal point. Our results demonstrated that laser light could generate a PA wave that could enhance cavitation not only at the surface of a slab, but also at depths when combined with ultrasound, suggesting that PUT may be effective in enhancing cavitation in a large range of soft tissues. Our results also demonstrated that the cavitation enhancement was based on the optical absorption of the targeted tissue, allowing for self-targeting treatments when optical contrast is present. Additionally, we demonstrated that for the greatest cavitation enhancement in deeper layers a focused laser beam geometry would be most effective.
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Affiliation(s)
- David Hazlewood
- Bioengineering Program and Institute for Bioengineering Research, University of Kansas, Lawrence, KS, United States of America
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3
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Critello CD, Pullano SA, Matula TJ, De Franciscis S, Serra R, Fiorillo AS. Recent developments on foaming mechanical and electronic techniques for the management of varicose veins. Expert Rev Med Devices 2019; 16:931-940. [PMID: 31622557 DOI: 10.1080/17434440.2019.1682549] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Introduction: Varicose veins are a common disease, causing significant impairment of quality of life to afflicted individuals. Conventional surgery has represented the traditional treatment for years, with significant post-operative complications. By the end of the 20th century, novel approaches had been developed to induce biochemical sclerosis into the treated vein in order to exclude it from blood circulation.Areas covered: Foaming techniques for treatment of varicose veins, both clinically-approved methods and those under experimental studies. A brief description of cavitation, which is the basis of microbubbles formation, and an overview of foam properties have been also provided, including a discussion on clinical efficacy and safety profile.Expert commentary: Foam sclerotherapy has rapidly gained popularity since it represents the most minimally invasive and cost-effective procedure in the short term. Several different methods of foam preparation have been described in literature. In general, the foam generation method may affect characteristics such as stability and bubble size distribution, which in turn affect the therapeutic action of foam itself. Therefore, the selection of a suitable foaming technique is of importance for treatment success. Future developments on foaming techniques are expected to make sclerotherapy, already an effective treatment, even safer and more versatile therapeutic procedure.
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Affiliation(s)
- C Davide Critello
- Department of Health Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Salvatore A Pullano
- Department of Health Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Thomas J Matula
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Stefano De Franciscis
- Department of Surgical and Medical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Raffaele Serra
- Department of Surgical and Medical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Antonino S Fiorillo
- Department of Health Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
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4
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Sadeghi-Goughari M, Jeon S, Kwon HJ. Enhancing Thermal Effect of Focused Ultrasound Therapy Using Gold Nanoparticles. IEEE Trans Nanobioscience 2019; 18:661-668. [PMID: 31449028 DOI: 10.1109/tnb.2019.2937327] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
High intensity focused ultrasound (HIFU) has gained increasing attention as a noninvasive therapeutic method for wide range of biomedical applications from drug delivery to cancer treatment. However, high level of ultrasonic power required for efficient HIFU treatment can cause adverse effects such as damage to surrounding healthy tissues and skin burns. One of the strategies to improve the therapeutic mechanism of HIFU is to use ultrasound absorption agents during the treatment. The objectives of current study are to investigate the feasibility of adopting gold nanoparticles (AuNPs) as ultrasound absorption agents to enhance the HIFU thermal ablation when the NPs were injected locally to the focal region; and to examine the dose effects of AuNPs on both heating and cooling mechanisms of HIFU. To this end, we conducted an experimental study on tissue-mimicking phantoms where AuNPs were injected to the focal region under the guidance of ultrasound imaging. A set of thermal parameters including temperature, specific absorption rate of acoustic energy, and cooling rate were measured to monitor the mechanism of AuNPs-mediated HIFU. The results suggest that both heating and cooling rates of HIFU procedure could be greatly improved by injecting AuNPs, which demonstrates the feasibility of using AuNPs to reduce the level of ultrasonic power from extracorporeal source for HIFU treatment.
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5
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Barnat N, Grisey A, Lecuelle B, Anquez J, Gerold B, Yon S, Aubry JF. Noninvasive vascular occlusion with HIFU for venous insufficiency treatment: preclinical feasibility experience in rabbits. ACTA ACUST UNITED AC 2019; 64:025003. [DOI: 10.1088/1361-6560/aaf58d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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6
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Pellow C, Goertz DE, Zheng G. Breaking free from vascular confinement: status and prospects for submicron ultrasound contrast agents. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 10:e1502. [PMID: 29148219 DOI: 10.1002/wnan.1502] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/23/2017] [Accepted: 09/30/2017] [Indexed: 12/11/2022]
Abstract
The development of encapsulated microbubbles (~1-6 μm) has expanded the utility of ultrasound from soft tissue anatomical imaging to not only functional intravascular imaging, but therapeutic interventions, with compelling studies of elicited biological effects. The large diameter of these bubbles has confined their utility to the vasculature, but converging interdisciplinary research pathways are giving rise to new submicron ultrasound contrast agents capable of extending their effects beyond the vascular compartment. This article reviews the status and prospects of exogenous agents including nanobubbles, echogenic liposomes, gas vesicles, cavitation seeds, and nanodroplets, and assesses outstanding criticisms preventing their advance. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Emerging Technologies.
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Affiliation(s)
- Carly Pellow
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Sunnybrook Research Institute, Toronto, Canada.,Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - David E Goertz
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Sunnybrook Research Institute, Toronto, Canada
| | - Gang Zheng
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
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7
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Goertz DE. An overview of the influence of therapeutic ultrasound exposures on the vasculature: high intensity ultrasound and microbubble-mediated bioeffects. Int J Hyperthermia 2015; 31:134-44. [PMID: 25716770 DOI: 10.3109/02656736.2015.1009179] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It is well established that the interaction of ultrasound with soft tissues can induce a wide range of bioeffects. One of the most important and complex of these interactions in the context of therapeutic ultrasound is with the vasculature. Potential vascular effects range from enhancing microvascular permeability to inducing vascular damage and vessel occlusion. While aspects of these effects are broadly understood, the development of improved approaches to exploit these effects and gain a more detailed mechanistic understanding is ongoing and largely anchored in preclinical research. Here a general overview of this established yet rapidly evolving topic is provided, with a particular emphasis on effects arising from high-intensity focused ultrasound and microbubble-mediated exposures.
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Affiliation(s)
- David E Goertz
- Department of Physical Sciences, Sunnybrook Health Sciences Center , Toronto, Ontario , Canada
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8
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Hoerig CL, Serrone JC, Burgess MT, Zuccarello M, Mast TD. Prediction and suppression of HIFU-induced vessel rupture using passive cavitation detection in an ex vivo model. J Ther Ultrasound 2014; 2:14. [PMID: 25232483 PMCID: PMC4159109 DOI: 10.1186/2050-5736-2-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 07/15/2014] [Indexed: 12/28/2022] Open
Abstract
Background Occlusion of blood vessels using high-intensity focused ultrasound (HIFU) is a potential treatment for arteriovenous malformations and other neurovascular disorders. However, attempting HIFU-induced vessel occlusion can also cause vessel rupture, resulting in hemorrhage. Possible rupture mechanisms include mechanical effects of acoustic cavitation and heating of the vessel wall. Methods HIFU exposures were performed on 18 ex vivo porcine femoral arteries with simultaneous passive cavitation detection. Vessels were insonified by a 3.3-MHz focused source with spatial-peak, temporal-peak focal intensity of 15,690–24,430 W/cm2 (peak negative-pressure range 10.92–12.52 MPa) and a 50% duty cycle for durations up to 5 min. Time-dependent acoustic emissions were recorded by an unfocused passive cavitation detector and quantified within low-frequency (10–30 kHz), broadband (0.3–1.1 MHz), and subharmonic (1.65 MHz) bands. Vessel rupture was detected by inline metering of saline flow, recorded throughout each treatment. Recorded emissions were grouped into ‘pre-rupture’ (0–10 s prior to measured point of vessel rupture) and ‘intact-vessel’ (>10 s prior to measured point of vessel rupture) emissions. Receiver operating characteristic curve analysis was used to assess the ability of emissions within each frequency band to predict vessel rupture. Based on these measurements associating acoustic emissions with vessel rupture, a real-time feedback control module was implemented to monitor acoustic emissions during HIFU treatment and adjust the ultrasound intensity, with the goal of maximizing acoustic power delivered to the vessel while avoiding rupture. This feedback control approach was tested on 10 paired HIFU exposures of porcine femoral and subclavian arteries, in which the focal intensity was stepwise increased from 9,117 W/cm2 spatial-peak temporal-peak (SPTP) to a maximum of 21,980 W/cm2, with power modulated based on the measured subharmonic emission amplitude. Time to rupture was compared between these feedback-controlled trials and paired controller-inactive trials using a paired Wilcoxon signed-rank test. Results Subharmonic emissions were found to be the most predictive of vessel rupture (areas under the receiver operating characteristic curve (AUROC) = 0.757, p < 10-16) compared to low-frequency (AUROC = 0.657, p < 10-11) and broadband (AUROC = 0.729, p < 10-16) emissions. An independent-sample t test comparing pre-rupture to intact-vessel emissions revealed a statistically significant difference between the two groups for broadband and subharmonic emissions (p < 10-3), but not for low-frequency emissions (p = 0.058). In a one-sided paired Wilcoxon signed-rank test, activation of the control module was shown to increase the time to vessel rupture (T- = 8, p = 0.0244, N = 10). In one-sided paired t tests, activation of the control module was shown to cause no significant difference in time-averaged focal intensity (t = 0.362, p = 0.363, N = 10), but was shown to cause delivery of significantly greater total acoustic energy (t = 2.037, p = 0.0361, N = 10). Conclusions These results suggest that acoustic cavitation plays an important role in HIFU-induced vessel rupture. In HIFU treatments for vessel occlusion, passive monitoring of acoustic emissions may be useful in avoiding hemorrhage due to vessel rupture, as shown in the rupture suppression experiments.
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Affiliation(s)
| | | | - Mark T Burgess
- University of Cincinnati, Cincinnati, OH 45267-0586, USA
| | | | - T Douglas Mast
- University of Cincinnati, Cincinnati, OH 45267-0586, USA
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9
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Shaw CJ, ter Haar GR, Rivens IH, Giussani DA, Lees CC. Pathophysiological mechanisms of high-intensity focused ultrasound-mediated vascular occlusion and relevance to non-invasive fetal surgery. J R Soc Interface 2014; 11:20140029. [PMID: 24671935 PMCID: PMC4006242 DOI: 10.1098/rsif.2014.0029] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/06/2014] [Indexed: 12/27/2022] Open
Abstract
High-intensity focused ultrasound (HIFU) is a non-invasive technology, which can be used occlude blood vessels in the body. Both the theory underlying and practical process of blood vessel occlusion are still under development and relatively sparse in vivo experimental and therapeutic data exist. HIFU would however provide an alternative to surgery, particularly in circumstances where serious complications inherent to surgery outweigh the potential benefits. Accordingly, the HIFU technique would be of particular utility for fetal and placental interventions, where open or endoscopic surgery is fraught with difficulty and likelihood of complications including premature delivery. This assumes that HIFU could be shown to safely and effectively occlude blood vessels in utero. To understand these mechanisms more fully, we present a review of relevant cross-specialty literature on the topic of vascular HIFU and suggest an integrative mechanism taking into account clinical, physical and engineering considerations through which HIFU may produce vascular occlusion. This model may aid in the design of HIFU protocols to further develop this area, and might be adapted to provide a non-invasive therapy for conditions in fetal medicine where vascular occlusion is beneficial.
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Affiliation(s)
- C. J. Shaw
- Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0HS, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - G. R. ter Haar
- Joint Department of Physics, Institute of Cancer Research: Royal Marsden NHSF Trust, Downs Road, Sutton, Surrey SM2 5PT, UK
| | - I. H. Rivens
- Joint Department of Physics, Institute of Cancer Research: Royal Marsden NHSF Trust, Downs Road, Sutton, Surrey SM2 5PT, UK
| | - D. A. Giussani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - C. C. Lees
- Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0HS, UK
- Department of Obstetrics and Gynaecology, University Hospitals Leuven, Campus Gasthuisberg, KU Leuven, Belgium
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10
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Techniques to expand patient selection for MRI-guided high-intensity focused ultrasound ablation of uterine fibroids. AJR Am J Roentgenol 2014; 202:443-51. [PMID: 24450690 DOI: 10.2214/ajr.13.10753] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE MRI-guided high-intensity focused ultrasound (HIFU) ablation is increasingly adopted for treating symptomatic uterine fibroids. As a noninvasive therapy performed on an outpatient basis, it has been viewed by patients to have distinct advantages over other treatment options. However, its breadth of clinical application is still limited. To address this issue, various techniques have been implemented. CONCLUSION In this article, we discuss techniques that contribute to widening patient selection for MRI-guided HIFU therapy of uterine fibroids.
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11
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Chen BT, Shieh J, Huang CW, Chen WS, Chen SR, Chen CS. Ultrasound thermal mapping based on a hybrid method combining physical and statistical models. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:115-129. [PMID: 24210856 DOI: 10.1016/j.ultrasmedbio.2013.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 09/09/2013] [Accepted: 09/10/2013] [Indexed: 06/02/2023]
Abstract
Non-invasive temperature measurement of tissues deep inside the body has great potential for clinical applications, such as temperature monitoring during thermal therapy and early diagnosis of diseases. We developed a novel method for both temperature estimation and thermal mapping that uses ultrasound B-mode radiofrequency data. The proposed method is a hybrid that combines elements of physical and statistical models to achieve higher precision and resolution of temperature variations and distribution. We propose a dimensionless combined index (CI) that combines the echo shift differential and signal intensity difference with a weighting factor relative to the distance from the heat source. In vitro experiments verified that the combined index has a strong linear relationship with temperature variation and can be used to effectively estimate temperature with an average relative error <5%. This algorithm provides an alternative for imaging guidance-based techniques during thermal therapy and could easily be integrated into existing ultrasound systems.
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Affiliation(s)
- Ben-Ting Chen
- Department of Civil Engineering, Chung Yuan Christian University, Chung Li, Taiwan
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12
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Yeh CL, Li PC, Shih WP, Huang PS, Kuo PL. Imaging monitored loosening of dense fibrous tissues using high-intensity pulsed ultrasound. Phys Med Biol 2013; 58:6779-96. [PMID: 24018912 DOI: 10.1088/0031-9155/58/19/6779] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Pulsed high-intensity focused ultrasound (HIFU) is proposed as a new alternative treatment for contracture of dense fibrous tissue. It is hypothesized that the pulsed-HIFU can release the contracted tissues by attenuating tensile stiffness along the fiber axis, and that the stiffness reduction can be quantitatively monitored by change of B-mode images. Fresh porcine tendons and ligaments were adapted to an ex vivo model and insonated with pulsed-HIFU for durations ranging from 5 to 30 min. The pulse length was 91 µs with a repetition frequency of 500 Hz, and the peak rarefactional pressure was 6.36 MPa. The corresponding average intensities were kept around 1606 W cm(-2) for ISPPA and 72.3 W cm(-2) for ISPTA. B-mode images of the tissues were acquired before and after pulsed-HIFU exposure, and the changes in speckle intensity and organization were analyzed. The tensile stiffness of the HIFU-exposed tissues along the longitudinal axis was examined using a stretching machine. Histology examinations were performed by optical and transmission electron microscopy. Pulsed-HIFU exposure significantly decreased the tensile stiffness of the ligaments and tendons. The intensity and organization of tissue speckles in the exposed region were also decreased. The speckle changes correlated well with the degree of stiffness alteration. Histology examinations revealed that pulsed-HIFU exposure probably damages tissues via a cavitation-mediated mechanism. Our results suggest that pulsed-HIFU with a low duty factor is a promising tool for developing new treatment strategies for orthopedic disorders.
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Affiliation(s)
- Chia-Lun Yeh
- Graduate Institute of Biomedical Electronics and Bioinformatics, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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13
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Celik H, Mahcicek DI, Senel OK, Wright GA, Atalar E. Tracking the position and rotational orientation of a catheter using a transmit array system. IEEE TRANSACTIONS ON MEDICAL IMAGING 2013; 32:809-817. [PMID: 23412592 DOI: 10.1109/tmi.2013.2247047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A new method for detecting the rotational orientation and tracking the position of an inductively coupled radio frequency (ICRF) coil using a transmit array system is proposed. The method employs a conventional body birdcage coil, but the quadrature hybrid is eliminated so that the two excitation channels can be used separately. The transmit array system provides RF excitations such that the body birdcage coil creates linearly polarized and changing RF pulses instead of a conventional rotational forward-polarized excitation. The receive coils and their operations are not modified. Inductively coupled RF coils are constructed on catheters for detecting rotational orientation and for tracking purposes. Signals from the anatomy and from tissue close to the ICRF coil are different due to the new RF excitation scheme: the ICRF coil can be separated from the anatomy in real time, and after doing so, a color-coded image is reconstructed. More importantly, this novel method enables a real-time calculation of the absolute rotational orientation of an ICRF coil constructed on a catheter. Modified FLASH and TrueFISP sequences are used for the experiments. The acquired images from this technique show the feasibility of different applications, such as catheter tracking. Furthermore, applications where knowledge of the rotational orientation of the catheter is important, such as magnetic resonance-guided endoluminal-focused ultrasound, RF ablation, side-looking optical imaging, and catheters with side ports for needles, become feasible with this method.
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Affiliation(s)
- Haydar Celik
- Electrical and Electronics Engineering Department, Bilkent University, TR-06800 Ankara, Turkey.
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Ziadloo A, Burks SR, Gold EM, Lewis BK, Chaudhry A, Merino MJ, Frenkel V, Frank JA. Enhanced homing permeability and retention of bone marrow stromal cells by noninvasive pulsed focused ultrasound. Stem Cells 2012; 30:1216-27. [PMID: 22593018 DOI: 10.1002/stem.1099] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bone marrow stromal cells (BMSCs) have shown significant promise in the treatment of disease, but their therapeutic efficacy is often limited by inefficient homing of systemically administered cells, which results in low number of cells accumulating at sites of pathology. BMSC home to areas of inflammation where local expression of integrins and chemokine gradients is present. We demonstrated that nondestructive pulsed focused ultrasound (pFUS) exposures that emphasize the mechanical effects of ultrasound-tissue interactions induced local and transient elevations of chemoattractants (i.e., cytokines, integrins, and growth factors) in the murine kidney. pFUS-induced upregulation of cytokines occurred through approximately 1 day post-treatment and returned to contralateral kidney levels by day 3. This window of significant increases in cytokine expression was accompanied by local increases of other trophic factors and integrins that have been shown to promote BMSC homing. When BMSCs were intravenously administered following pFUS treatment to a single kidney, enhanced homing, permeability, and retention of BMSC was observed in the treated kidney versus the contralateral kidney. Histological analysis revealed up to eight times more BMSC in the peritubular regions of the treated kidneys on days 1 and 3 post-treatment. Furthermore, cytokine levels in pFUS-treated kidneys following BMSC administration were found to be similar to controls, suggesting modulation of cytokine levels by BMSC. pFUS could potentially improve cell-based therapies as a noninvasive modality to target homing by establishing local chemoattractant gradients and increasing expression of integrins to enhance tropism of cells toward treated tissues.
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Affiliation(s)
- Ali Ziadloo
- Laboratory of Diagnostic Radiology Research, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA
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15
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Removing vascular obstructions: a challenge, yet an opportunity for interventional microdevices. Biomed Microdevices 2012; 14:511-32. [PMID: 22331446 DOI: 10.1007/s10544-011-9627-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cardiovascular diseases are the leading cause of death worldwide; they are mainly due to vascular obstructions which, in turn, are mainly caused by thrombi and atherosclerotic plaques. Although a variety of removal strategies has been developed for the considered obstructions, none of them is free from limitations and conclusive. The present paper analyzes the physical mechanisms underlying state-of-art removal strategies and classifies them into chemical, mechanical, laser and hybrid (namely chemo-mechanical and mechano-chemical) approaches, while also reviewing corresponding commercial/research tools/devices and procedures. Furthermore, challenges and opportunities for interventional micro/nanodevices are highlighted. In this spirit, the present review should support engineers, researchers active in the micro/nanotechnology field, as well as medical doctors in the development of innovative biomedical solutions for treating vascular obstructions. Data were collected by using the ISI Web of Knowledge portal, buyer's guides and FDA databases; devices not reported on scientific publications, as well as commercial devices no more for sale were discarded. Nearly 70% of the references were published since 2006, 55% since 2008; these percentages respectively raise to 85% and 65% as regards the section specifically reviewing state-of-art removal tools/devices and procedures.
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16
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Wood SC, Antony S, Brown RP, Chen J, Gordon EA, Hitchins VM, Zhang Q, Liu Y, Maruvada S, Harris GR. Effects of ultrasound and ultrasound contrast agent on vascular tissue. Cardiovasc Ultrasound 2012; 10:29. [PMID: 22805356 PMCID: PMC3493263 DOI: 10.1186/1476-7120-10-29] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 06/25/2012] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Ultrasound (US) imaging can be enhanced using gas-filled microbubble contrast agents. Strong echo signals are induced at the tissue-gas interface following microbubble collapse. Applications include assessment of ventricular function and virtual histology. AIM While ultrasound and US contrast agents are widely used, their impact on the physiological response of vascular tissue to vasoactive agents has not been investigated in detail. METHODS AND RESULTS In the present study, rat dorsal aortas were treated with US via a clinical imaging transducer in the presence or absence of the US contrast agent, Optison. Aortas treated with both US and Optison were unable to contract in response to phenylephrine or to relax in the presence of acetylcholine. Histology of the arteries was unremarkable. When the treated aortas were stained for endothelial markers, a distinct loss of endothelium was observed. Importantly, terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) staining of treated aortas demonstrated incipient apoptosis in the endothelium. CONCLUSIONS Taken together, these ex vivo results suggest that the combination of US and Optison may alter arterial integrity and promote vascular injury; however, the in vivo interaction of Optison and ultrasound remains an open question.
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Affiliation(s)
- Steven C Wood
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Sible Antony
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
- School of Medicine and Health Sciences, The George Washington University, 2300, Eye Street, NW, Washington, DC, 20037, USA
| | - Ronald P Brown
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Jin Chen
- Food and Drug Administration, Center for Drug Evaluation and Research (CDER), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Edward A Gordon
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Victoria M Hitchins
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Qin Zhang
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Yunbo Liu
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Subha Maruvada
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Gerald R Harris
- Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
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17
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Zhou Y, Zia J, Warren C, Starr FL, Brayman AA, Crum LA, Hwang JH. Targeted long-term venous occlusion using pulsed high-intensity focused ultrasound combined with a pro-inflammatory agent. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:1653-1658. [PMID: 21821352 PMCID: PMC4637170 DOI: 10.1016/j.ultrasmedbio.2011.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Revised: 06/13/2011] [Accepted: 06/16/2011] [Indexed: 05/31/2023]
Abstract
Esophageal and gastric varices are associated with significant morbidity and mortality for cirrhotic patients. The current modalities available for treating bleeding esophageal and gastric varices, namely endoscopic band ligation and sclerotherapy, require frequent sessions to obtain effective thrombosis and are associated with significant adverse effects. A more effective therapy that results in long-term vascular occlusion has the potential to improve patient outcomes. In this study, we investigated a new potential method for inducing long-term vascular occlusion by targeting segments of a rabbit's auricular vein in vivo with low-duty-cycle, high-peak-rarefaction pressure (9 MPa), pulsed high-intensity focused ultrasound in the presence of intravenously administered ultrasound microbubbles followed by local injection of fibrinogen and a pro-inflammatory agent (ethanol, cyanoacrylate or morrhuate sodium). The novel method introduced in this study resulted in acute and long-term complete vascular occlusions when injecting a pro-inflammatory agent with fibrinogen. Future investigation and translational studies are needed to assess its clinical applicability.
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Affiliation(s)
- Yufeng Zhou
- Division of Engineering Mechanics, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | - Jasmine Zia
- Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Cinderella Warren
- Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Frank L. Starr
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Andrew A. Brayman
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Lawrence A. Crum
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Joo Ha Hwang
- Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
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Chen WS, Shen CC, Wang JC, Ko CT, Liu HL, Ho MC, Chen CN, Yeh CK. Single-element ultrasound transducer for combined vessel localization and ablation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2011; 58:766-775. [PMID: 21507754 DOI: 10.1109/tuffc.2011.1869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This report describes a system that utilizes a single high-intensity focused ultrasound (HIFU) transducer for both the localization and ablation of arteries with internal diameters of 0.5 and 1.3 mm. In vitro and in vivo tests were performed to demonstrate both the imaging and ablation functionalities of this system. For imaging mode, pulsed acoustic waves (3 cycles for in vitro and 10 cycles for in vivo tests, 2 MPa peak pressure) were emitted from the 2-MHz HIFU transducer, and the backscattered ultrasonic signal was collected by the same transducer to calculate Doppler shifts in the target region. The maximum signal amplitude of the Doppler shift was used to determine the location of the target vessel. The operation mode was then switched to the therapeutic mode and vessel occlusion was successfully produced by high-intensity continuous HIFU waves (12 MPa) for 60 s. The system was then switched back to imaging mode for residual flow to determine the need for a second ablation treatment. The new system might be used to target and occlude unwanted vessels such as vasculature around tumors, and to help with tumor destruction.
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Affiliation(s)
- Wen-Shiang Chen
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei, Taiwan
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19
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