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Muth V, Gassner JMGV, Moosburner S, Lurje G, Michelotto J, Strobl F, Knaub K, Engelmann C, Tacke F, Selzner M, Pratschke J, Sauer IM, Raschzok N. Ex Vivo Liver Machine Perfusion: Comprehensive Review of Common Animal Models. Tissue Eng Part B Rev 2023; 29:10-27. [PMID: 35848526 DOI: 10.1089/ten.teb.2022.0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The most common preservation technique for liver grafts is static cold storage. Due to the organ shortage for liver transplantation (LT), extended criteria donor (ECD) allografts are increasingly used-despite the higher risk of inferior outcome after transplantation. Ex vivo liver machine perfusion (MP) has been developed to improve the outcome of transplantation, especially with ECD grafts, and is currently under evaluation in clinical trials. We performed a literature search on PubMed and ISI Web of Science to assemble an overview of rodent and porcine animal models of ex vivo liver MP for transplantation, which is essential for the present and future development of clinical liver MP. Hypothermic, subnormothermic, and normothermic MP systems have been successfully used for rat and pig LT. In comparison with hypothermic systems, normothermic perfusion often incorporates a dialysis unit. Moreover, it enables metabolic assessment of liver grafts. Allografts experiencing warm ischemic time have a superior survival rate after MP compared with cold storage alone, irrespective of the temperature used for perfusion. Furthermore, ex vivo MP improves the outcome of regular and ECD liver grafts in animal models. Small and large animal models of ex vivo liver MP are available to foster the further development of this new technology. Impact Statement Ex vivo machine perfusion is an important part of current research in the field of liver transplantation. While evidence for improve storage is constantly rising, the development of future applications such as quality assessment and therapeutic interventions necessitates robust animal models. This review is intended to provide an overview of this technology in common large and small animal models and to give an outlook on future applications. Moreover, we describe developmental steps that can be followed by others, and which can help to decrease the number of animals used for experiments based on the replace, reduce, refine concept.
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Affiliation(s)
- Vanessa Muth
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Joseph M G V Gassner
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Clinician Scientist Program, BIH Academy, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Simon Moosburner
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Clinician Scientist Program, BIH Academy, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Georg Lurje
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Julian Michelotto
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Felix Strobl
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kristina Knaub
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Cornelius Engelmann
- Department of Hepatology and Gastroenterology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Frank Tacke
- Department of Hepatology and Gastroenterology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Markus Selzner
- Department of Surgery, Abdominal Transplant and HPB Surgery, Ajmera Family Transplant Centre, Toronto General Hospital, Toronto, Canada
| | - Johann Pratschke
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Igor M Sauer
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nathanael Raschzok
- Department of Surgery, Experimental Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Clinician Scientist Program, BIH Academy, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
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Ortiz CB, Dang A, Derrick K, O'Donnell B, Bitar R, Parker M, Veraza R, Bunegin L, Borrego M, Yamaguchi S, Walker JA, Lopera J. Creation of an Ex Vivo Renal Perfusion Model to Investigate Microwave Ablation. J Vasc Interv Radiol 2023; 34:40-45.e2. [PMID: 36244634 DOI: 10.1016/j.jvir.2022.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/20/2022] [Accepted: 10/04/2022] [Indexed: 11/16/2022] Open
Abstract
This study hypothesized that an ex vivo renal perfusion model can create smaller microwave ablation (MWA) measurements during perfused states compared with nonperfused states across multiple device settings. Nine bovine kidneys, a fluoroscopic compatible perfusion model, and a commercially-available clinical MWA system were used to perform 72 ablations (36 perfused and 36 nonperfused) at 9 different device settings. Comparing perfused and nonperfused ablations at each device setting, significant differences in volume existed for 6 of 9 settings (P < .05). Collapsed across time settings, the ablation volumes by power were the following (perfused and nonperfused, P value): 60 W, 2.3 cm3 ± 1.0 and 7.2 cm3 ± 2.7, P < .001; 100 W, 5.4 cm3 ± 2.1 and 11.5 cm3 ± 5.6, P < .01; and 140 W, 11.2 cm3 ± 3.7 and 18.7 cm3 ± 6.3, P < .01. Applied power correlated with ablation volume: perfused, 0.021 cm3/W and R = 0.462, P = .004, and nonperfused, 0.029 cm3/W and R = 0.565, P < .001. These results support that an ex vivo perfused organ system can evaluate MWA systems and demonstrate heat sink perfusion effects of decreased ablation size.
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Affiliation(s)
- Carlos B Ortiz
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Interventional Radiology, Department of Radiology, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas.
| | - Annie Dang
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - Kade Derrick
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - Barrett O'Donnell
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Interventional Radiology, Department of Radiology, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - Ryan Bitar
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - Matthew Parker
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Interventional Radiology, Department of Radiology, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | | | - Leonid Bunegin
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Vascular Perfusion Solutions, San Antonio, Texas
| | - Marina Borrego
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Interventional Radiology, Department of Radiology, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - Seiji Yamaguchi
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Transplant Surgery, Department of Surgery, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - John A Walker
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Interventional Radiology, Department of Radiology, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
| | - Jorge Lopera
- Long School of Medicine, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas; Division of Interventional Radiology, Department of Radiology, The University of Texas Health Sciences Center San Antonio, San Antonio, Texas
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Garza L, Bitar R, O'Donnell B, Parker M, Ortiz C, Hyman C, Walker J, Song HY, Lopera J. Creation of an ex-vivo bovine kidney flow model for testing embolic agents: work in progress. CVIR Endovasc 2021; 4:20. [PMID: 33534088 PMCID: PMC7859154 DOI: 10.1186/s42155-021-00210-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 01/27/2021] [Indexed: 11/23/2022] Open
Abstract
Objectives To develop an ex- vivo perfusion flow model using a bovine kidney for future testing of embolic agents in an inexpensive and easy way. Methods Six bovine adult kidneys were used for this study. Kidneys were cannulated and perfused via a roller pump. Three embolic agents, coils, Gelfoam, and a glue mixture of Histoacryl + Lipiodol, were deployed by targeting three secondary segmental arteries per kidney via a 5Fr catheter under fluoroscopic guidance. Cannulation time, success rate of segmental artery selection and embolic agent deployment, total operational time, and fluoroscopy dose were recorded. Results Average kidney weight was 0.752 +/− 0.094 kg. All six bovine kidneys were successfully cannulated in 21.6 min +/− 3.0 min. Deployment of coils and glue was achieved in every case (12/12); however, Gelfoam injection was not successful in one instance (5/6, 83%). Coil deployment demonstrated no embolic effect while Gelfoam and glue injections demonstrated decreased distal contrast filling post-embolization. Mean dose area product was 12.9 ± 1.8 Gy·cm2, fluoroscopy time was 10 ± 4 min and operational time was 27 ± 8 min. Conclusions We describe the creation of an ex vivo bovine kidney flow model for the preclinical evaluation of different embolic materials. The flow model can be modified to provide extensive bench testing and it is a promising tool for hands -on training in basic and advanced embolization techniques .
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Affiliation(s)
- Luis Garza
- Long School of Medicine, University of Texas Health Science Center, 7703 Floyd Curl Drive San Antonio, San Antonio, TX, 78229, USA
| | - Ryan Bitar
- Long School of Medicine, University of Texas Health Science Center, 7703 Floyd Curl Drive San Antonio, San Antonio, TX, 78229, USA
| | - Barrett O'Donnell
- Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Matthew Parker
- Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Carlos Ortiz
- Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Charles Hyman
- Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - John Walker
- Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Ho-Young Song
- Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA.,Department of Diagnostic Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jorge Lopera
- Long School of Medicine, University of Texas Health Science Center, 7703 Floyd Curl Drive San Antonio, San Antonio, TX, 78229, USA. .,Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA.
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Gao H, Wu S, Wang X, Hu R, Zhou Z, Sun X. Temperature simulation of microwave ablation based on improved specific absorption rate method compared to phantom measurements. Comput Assist Surg (Abingdon) 2017; 22:9-17. [DOI: 10.1080/24699322.2017.1378605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Hongjian Gao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Shuicai Wu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Xiaoru Wang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Rui Hu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Zhuhuang Zhou
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Xuecong Sun
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
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Dodd GD, Lanctot AC, Lind KE. Effect of Change in Portal Vein Flow Rates on Hepatic Ablations Created with a Bipolar Radiofrequency Ablation Device. Radiology 2017; 283:399-407. [DOI: 10.1148/radiol.2016152562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Gerald D. Dodd
- From the Department of Radiology, School of Medicine, University of Colorado, Mail Stop L954, 12401 E 17th Ave, PO Box 6510, Aurora, CO 80045
| | - Anthony C. Lanctot
- From the Department of Radiology, School of Medicine, University of Colorado, Mail Stop L954, 12401 E 17th Ave, PO Box 6510, Aurora, CO 80045
| | - Kimberly E. Lind
- From the Department of Radiology, School of Medicine, University of Colorado, Mail Stop L954, 12401 E 17th Ave, PO Box 6510, Aurora, CO 80045
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Chang S, Lanctot AC, McCarter MD, Roberts KM, Glueck DH, Dodd GD. The prediction of radiofrequency ablation zone volume using vascular indices of 3-dimensional volumetric colour Doppler ultrasound in an in vitro blood-perfused bovine liver model. Br J Radiol 2016; 90:20160661. [PMID: 27925468 DOI: 10.1259/bjr.20160661] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE To determine the most reliable predictor of radiofrequency (RF) ablation zone volume among three-dimensional (3D) volumetric colour Doppler vascular indices in an in vitro blood-perfused bovine liver model. METHODS 3D colour Doppler volume data of the local hepatic parenchyma were acquired from 37 areas of 13 bovine livers connected to an in vitro oxygenated blood perfusion system. Doppler vascular indices of vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were obtained from the volume data using 3D volume analysis software. 37 RF ablations were performed at the same locations where the ultrasound data were obtained from. The relationship of these vascular indices and the ablation zone volumes measured from gross specimens were analyzed using a general linear mixed model fit with random effect for liver and backward stepwise regression analysis. RESULTS FI was significantly associated with ablation zone volumes measured on gross specimens (p = 0.0047), but explained little of the variance (Rβ2 = 0.21). Ablation zone volume decreased by 0.23 cm3 (95% confidence interval: -0.38, -0.08) for every 1 increase in FI. Neither VI nor VFI was significantly associated with ablation zone volumes (p > 0.05). CONCLUSION Although FI was associated with ablation zone volumes, it could not sufficiently explain their variability, limiting its clinical applicability. VI, FI and VFI are not clinically useful in the prediction of RF ablation zone volume in the liver. Advances in knowledge: Despite a significant association of FI with ablation zone volumes, VI, FI and VFI cannot be used for their prediction. Different Doppler vascular indices need to be investigated for clinical use.
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Affiliation(s)
- Samuel Chang
- 1 Department of Radiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anthony C Lanctot
- 1 Department of Radiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Martin D McCarter
- 2 Department of Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Katherine M Roberts
- 3 Department of Biostatistics and Informatics, University of Colorado School of Public Health, Aurora, CO, USA
| | - Deborah H Glueck
- 3 Department of Biostatistics and Informatics, University of Colorado School of Public Health, Aurora, CO, USA
| | - Gerald D Dodd
- 1 Department of Radiology, University of Colorado School of Medicine, Aurora, CO, USA
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Lee JK, Siripongsakun S, Bahrami S, Raman SS, Sayre J, Lu DS. Microwave ablation of liver tumors: degree of tissue contraction as compared to RF ablation. Abdom Radiol (NY) 2016; 41:659-66. [PMID: 27039193 DOI: 10.1007/s00261-016-0725-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE To compare the amount of tissue contraction after microwave (MW) versus radiofrequency (RF) ablation of liver tumors. MATERIALS AND METHODS Seventy-five hepatic tumors in 65 patients who underwent percutaneous MW or RF ablations were included in this retrospective study. All patients underwent MRI within 6 months before the ablation and 24 h after the procedure. Two blinded radiologists, by consensus, performed measurements on the corresponding series of pre and post-ablation MRI. Absolute and relative contraction of liver, tumor, and control were calculated and compared. RESULTS Thirty-one patients underwent MW ablations, and 44 patients underwent RF ablations. The absolute and relative contraction of the ablation zone were significantly greater with MW than RF ablation (p = 0.003 to <0.001). Thirty-two lesions were visible on both pre- and post-ablation MRI. MW ablation had significantly more tumor contraction as compared to RF ablation (p = 0.003 to 0.009). The control measurements demonstrated no significant difference in normal tissue variation between MW and RF groups. CONCLUSIONS MW ablation of hepatic tumors produced significantly more contraction of tumor and ablated hepatic tissue compared to RF ablation. Tissue contraction should be taken into account during pre-procedural planning and assessing treatment response by comparing pre- and post-ablation images.
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Affiliation(s)
- Jeong Kyong Lee
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Radiology, Ewha Womans University, Seoul, Korea
| | - Surachate Siripongsakun
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Radiology, Chalubhorn Hospital, Bangkok, Thailand
| | - Simin Bahrami
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Steven S Raman
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - James Sayre
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Biostatistics, School of Public Health, UCLA, Los Angeles, CA, USA
| | - David S Lu
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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Bedoya M, del Rio AM, Chiang J, Brace CL. Microwave ablation energy delivery: influence of power pulsing on ablation results in an ex vivo and in vivo liver model. Med Phys 2015; 41:123301. [PMID: 25471983 DOI: 10.1118/1.4901312] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE The purpose of this study was to compare the impact of continuous and pulsed energy deliveries on microwave ablation growth and shape in unperfused and perfused liver models. METHODS A total of 15 kJ at 2.45 GHz was applied to ex vivo bovine liver using one of five delivery methods (n = 50 total, 10 per group): 25 W continuous for 10 min (25 W average), 50 W continuous for 5 min (50 W average), 100 W continuous for 2.5 min (100 W average), 100 W pulsed for 10 min (25 W average), and 100 W pulsed for 5 min (50 W average). A total of 30 kJ was applied to in vivo porcine livers (n = 35, 7 per group) using delivery methods similar to the ex vivo study, but with twice the total ablation time to offset heat loss to blood perfusion. Temperatures were monitored 5-20 mm from the ablation antenna, with values over 60 °C indicating acute cellular necrosis. Comparisons of ablation size and shape were made between experimental groups based on total energy delivery, average power applied, and peak power using ANOVA with post-hoc pairwise tests. RESULTS No significant differences were noted in ablation sizes or circularities between pulsed and continuous groups in ex vivo tissue. Temperature data demonstrated more rapid heating in pulsed ablations, suggesting that pulsing may overcome blood perfusion and coagulate tissues more rapidly in vivo. Differences in ablation size and shape were noted in vivo despite equivalent energy delivery among all groups. Overall, the largest ablation volume in vivo was produced with 100 W continuous for 5 min (265.7 ± 208.1 cm(3)). At 25 W average, pulsed-power ablation volumes were larger than continuous-power ablations (67.4 ± 34.5 cm(3) versus 23.6 ± 26.5 cm(3), P = 0.43). Similarly, pulsed ablations produced significantly greater length (P ≤ 0.01), with increase in diameter (P = 0.09) and a slight decrease in circularity (P = 0.97). When comparing 50 W average power groups, moderate differences in size were noted (P ≥ 0.06) and pulsed ablations were again slightly more circular. CONCLUSIONS Pulsed energy delivery created larger ablation zones at low average power compared to continuous energy delivery in the presence of blood perfusion. Shorter duty cycles appear to provide greater benefit when pulsing.
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Affiliation(s)
- Mariajose Bedoya
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Alejandro Muñoz del Rio
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Jason Chiang
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Christopher L Brace
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705; and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705
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Dodd GD, Kreidler SM, Lanctot AC, Glueck DH. Effect of Change in Portal Venous Blood Flow Rates on the Performance of a 2.45-GHz Microwave Ablation Device. Radiology 2015; 277:727-32. [PMID: 26030660 DOI: 10.1148/radiol.2015150102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To investigate the effect of change in portal venous blood flow rates on the size and shape of ablations created by a 2.45-GHz microwave ablation device. MATERIALS AND METHODS This study was exempt from review by the institutional animal care and use committee. An in vitro bovine liver model perfused with autologous blood via the portal vein at five flow rates (60, 70, 80, 90, and 100 mL/min per 100 g of liver) was used to evaluate the effect of change in flow rates on the size and shape of coagulation created by a 2.45-GHz, 140-W microwave ablation device operated for 5 and 10 minutes. Three ablations per ablation time were conducted in each of 10 livers, with two livers perfused at each flow rate. Short- and long-axis diameters were measured from gross specimens, and volume and sphericity index were calculated. General linear mixed models that accounted for correlations within the liver were used to evaluate the effects of lobe, flow, and ablation time on size and sphericity index of ablations. RESULTS Flow did not have a significant effect on the size or shape of coagulation created at 5 or 10 minutes (P > .05 for all tests). The mean short- and long-axis diameters and volume were 3.2 cm (95% confidence interval [CI]: 3.1, 3.3), 5.6 cm (95% CI: 5.4, 5.8), and 30.2 cm(3) (95% CI: 28.4, 32.1) for the 5-minute ablations and 3.8 cm (95% CI: 3.7, 3.9), 6.5 cm (95% CI: 6.3, 6.7), and 49.3 cm(3) (95% CI: 47.5, 51.2), for the 10-minute ablations, respectively. The mean sphericity index for both 5- and 10-minute ablations was 34.4% (95% CI: 32%, 36.7%). CONCLUSION Change in portal venous blood flow rates did not have an effect on the size and shape of ablations created by a 2.45-GHz microwave ablation device.
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Affiliation(s)
- Gerald D Dodd
- From the Department of Radiology, School of Medicine (G.D.D., S.M.K., A.C.L.), and School of Public Health (D.H.G.), University of Colorado, 12401 E 17th Ave, Mail Stop L954, PO Box 6510, Aurora, CO 80045
| | - Sarah M Kreidler
- From the Department of Radiology, School of Medicine (G.D.D., S.M.K., A.C.L.), and School of Public Health (D.H.G.), University of Colorado, 12401 E 17th Ave, Mail Stop L954, PO Box 6510, Aurora, CO 80045
| | - Anthony C Lanctot
- From the Department of Radiology, School of Medicine (G.D.D., S.M.K., A.C.L.), and School of Public Health (D.H.G.), University of Colorado, 12401 E 17th Ave, Mail Stop L954, PO Box 6510, Aurora, CO 80045
| | - Deborah H Glueck
- From the Department of Radiology, School of Medicine (G.D.D., S.M.K., A.C.L.), and School of Public Health (D.H.G.), University of Colorado, 12401 E 17th Ave, Mail Stop L954, PO Box 6510, Aurora, CO 80045
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Dodd GD, Dodd NA, Lanctot AC, Glueck DA. Effect of Variation of Portal Venous Blood Flow on Radiofrequency and Microwave Ablations in a Blood-perfused Bovine Liver Model. Radiology 2013; 267:129-36. [DOI: 10.1148/radiol.12120486] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Huang L, Dodd GD 3rd, Lanctot AC. Radiofrequency ablation of the liver: effect of variation of portal venous blood flow on lesion size in an in-vitro perfused bovine liver. Acad Radiol 2012; 19:1018-22. [PMID: 22591722 DOI: 10.1016/j.acra.2012.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 03/30/2012] [Accepted: 04/02/2012] [Indexed: 12/11/2022]
Abstract
RATIONALE AND OBJECTIVES An in vitro perfused bovine liver model was used to evaluate the relationship between the sizes of radiofrequency ablation lesions and variation in portal venous blood flow. MATERIALS AND METHODS Fourteen bovine livers were perfused with autologous heparinized blood at 37°C and 40% to 50% oxygenation via the portal vein. Flow rates were adjusted from 10 to 50 mL/min/100 g tissue. A 480-kHz generator and a 3.0-cm monopolar internally cooled electrode were used to create 57 ablations. The long-axis diameter, short-axis diameter (SAD), and volume of each ablation zone were measured and calculated from the dissected livers. Correlations between SAD, long-axis diameter, and volume versus blood flow were assessed using linear regression analysis. RESULTS SAD and lesion volume demonstrated inverse linear correlations with blood flow (for SAD, y = -0.044x + 3.925, r = 0.836, P < .001; for volume, y = -0.556x + 31.574, r = 0.842, P < .001). A 10 mL/min/100 g change in flow rate produced an average 4.4 ± 0.4 mm change in SAD and an average 5.6 ± 0.5 cm(3) change in volume. Long-axis diameter was not correlated with blood flow (y = -0.7694x + 4.1899, r = 0.2173, P = .111). CONCLUSIONS The SAD and volume of radiofrequency ablation lesions have statistically significant inverse linear correlations with portal venous blood flow, with an average 4.4-mm change in SAD and an average 5.6-cm(3) change in volume for each 10 mL/min/100 g change in flow rate.
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Burns SK, Dodd GD, McManus LM, Cardan RA, Peng Q, Orsi MD, Head HW, Blakemore DL, Blume JD, Fullerton GD, Green TJ. 3T Magnetic Resonance Imaging Accurately Depicts Radiofrequency Ablation Zones in a Blood-perfused Bovine Liver Model. J Vasc Interv Radiol 2012; 23:801-8. [DOI: 10.1016/j.jvir.2012.01.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 01/25/2012] [Accepted: 01/26/2012] [Indexed: 10/28/2022] Open
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