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López-Martínez S, Simón C, Santamaria X. Normothermic Machine Perfusion Systems: Where Do We Go From Here? Transplantation 2024; 108:22-44. [PMID: 37026713 DOI: 10.1097/tp.0000000000004573] [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: 04/08/2023]
Abstract
Normothermic machine perfusion (NMP) aims to preserve organs ex vivo by simulating physiological conditions such as body temperature. Recent advancements in NMP system design have prompted the development of clinically effective devices for liver, heart, lung, and kidney transplantation that preserve organs for several hours/up to 1 d. In preclinical studies, adjustments to circuit structure, perfusate composition, and automatic supervision have extended perfusion times up to 1 wk of preservation. Emerging NMP platforms for ex vivo preservation of the pancreas, intestine, uterus, ovary, and vascularized composite allografts represent exciting prospects. Thus, NMP may become a valuable tool in transplantation and provide significant advantages to biomedical research. This review recaps recent NMP research, including discussions of devices in clinical trials, innovative preclinical systems for extended preservation, and platforms developed for other organs. We will also discuss NMP strategies using a global approach while focusing on technical specifications and preservation times.
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Affiliation(s)
- Sara López-Martínez
- Carlos Simon Foundation, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Carlos Simón
- Carlos Simon Foundation, Centro de Investigación Príncipe Felipe, Valencia, Spain
- Department of Obstetrics and Gynecology, Universidad de Valencia, Valencia, Spain
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX
| | - Xavier Santamaria
- Carlos Simon Foundation, Centro de Investigación Príncipe Felipe, Valencia, Spain
- INCLIVA Biomedical Research Institute, Valencia, Spain
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Hyperspectral Imaging for Viability Assessment of Human Liver Allografts During Normothermic Machine Perfusion. Transplant Direct 2022; 8:e1420. [PMID: 36406899 PMCID: PMC9671746 DOI: 10.1097/txd.0000000000001420] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 01/24/2023] Open
Abstract
UNLABELLED Normothermic machine perfusion (NMP) is nowadays frequently utilized in liver transplantation. Despite commonly accepted viability assessment criteria, such as perfusate lactate and perfusate pH, there is a lack of predictive organ evaluation strategies to ensure graft viability. Hyperspectral imaging (HSI)-as an optical imaging modality increasingly applied in the biomedical field-might provide additional useful data regarding allograft viability and performance of liver grafts during NMP. METHODS Twenty-five deceased donor liver allografts were included in the study. During NMP, graft viability was assessed conventionally and by means of HSI. Images of liver parenchyma were acquired at 1, 2, and 4 h of NMP, and subsequently analyzed using a specialized HSI acquisition software to compute oxygen saturation, tissue hemoglobin index, near-infrared perfusion index, and tissue water index. To analyze the association between HSI parameters and perfusate lactate as well as perfusate pH, we performed simple linear regression analysis. RESULTS Perfusate lactate at 1, 2, and 4 h NMP was 1.5 [0.3-8.1], 0.9 [0.3-2.8], and 0.9 [0.1-2.2] mmol/L. Perfusate pH at 1, 2, and 4 h NMP was 7.329 [7.013-7.510], 7.318 [7.081-7.472], and 7.265 [6.967-7.462], respectively. Oxygen saturation predicted perfusate lactate at 1 and 2 h NMP (R2 = 0.1577, P = 0.0493; R2 = 0.1831, P = 0.0329; respectively). Tissue hemoglobin index predicted perfusate lactate at 1, 2, and 4 h NMP (R2 = 0.1916, P = 0.0286; R2 = 0.2900, P = 0.0055; R2 = 0.2453, P = 0.0139; respectively). CONCLUSIONS HSI may serve as a noninvasive tool for viability assessment during NMP. Further evaluation and validation of HSI parameters are warranted in larger sample sizes.
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Evaluation of the Influence of Short Tourniquet Ischemia on Tissue Oxygen Saturation and Skin Temperature Using Two Portable Imaging Modalities. J Clin Med 2022; 11:jcm11175240. [PMID: 36079169 PMCID: PMC9457061 DOI: 10.3390/jcm11175240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/24/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The exact influence of tourniquet ischemia on a treated extremity remains unclear. METHODS Twenty patients received an operation on one hand under tourniquet ischemia. Twenty healthy volunteers received 10 min of tourniquet ischemia on one of their arms. Measurements of tissue oxygen saturation using near-infrared reflectance-based imaging and skin temperature of the dorsum of the hand were performed at five different timepoints (t0 was performed just before the application of the tourniquet ischemia, t1 directly after the application of the tourniquet ischemia, t2 before the release of the ischemia, t3 directly after the release of the ischemia, and t4 on the following day). RESULTS In both groups, tissue oxygen saturation dropped after the application of the tourniquet ischemia compared to t0 and increased after the release of the tourniquet ischemia. In the patient group, tissue oxygen saturation at t4 was higher compared to t0; in contrast, the level of tissue oxygen saturation in the participant group dropped slightly at t4 compared to t0. The measured skin temperature in the patient group showed an increase during the observation period, while it continuously decreased in the group of healthy participants. CONCLUSIONS Short-term ischemia did not appear to permanently restrict perfusion in this study design. The non-invasive imaging modalities used were easy to handle and allowed repetitive measurement.
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Fodor M, Lanser L, Hofmann J, Otarashvili G, Pühringer M, Cardini B, Oberhuber R, Resch T, Weissenbacher A, Maglione M, Margreiter C, Zelger P, Pallua JD, Öfner D, Sucher R, Hautz T, Schneeberger S. Hyperspectral Imaging as a Tool for Viability Assessment During Normothermic Machine Perfusion of Human Livers: A Proof of Concept Pilot Study. Transpl Int 2022; 35:10355. [PMID: 35651880 PMCID: PMC9150258 DOI: 10.3389/ti.2022.10355] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 04/22/2022] [Indexed: 11/23/2022]
Abstract
Normothermic machine perfusion (NMP) allows for ex vivo viability and functional assessment prior to liver transplantation (LT). Hyperspectral imaging represents a suitable, non-invasive method to evaluate tissue morphology and organ perfusion during NMP. Liver allografts were subjected to NMP prior to LT. Serial image acquisition of oxygen saturation levels (StO2), organ hemoglobin (THI), near-infrared perfusion (NIR) and tissue water indices (TWI) through hyperspectral imaging was performed during static cold storage, at 1h, 6h, 12h and at the end of NMP. The readouts were correlated with perfusate parameters at equivalent time points. Twenty-one deceased donor livers were included in the study. Seven (33.0%) were discarded due to poor organ function during NMP. StO2 (p < 0.001), THI (p < 0.001) and NIR (p = 0.002) significantly augmented, from static cold storage (pre-NMP) to NMP end, while TWI dropped (p = 0.005) during the observational period. At 12-24h, a significantly higher hemoglobin concentration (THI) in the superficial tissue layers was seen in discarded, compared to transplanted livers (p = 0.036). Lactate values at 12h NMP correlated negatively with NIR perfusion index between 12 and 24h NMP and with the delta NIR perfusion index between 1 and 24h (rs = -0.883, p = 0.008 for both). Furthermore, NIR and TWI correlated with lactate clearance and pH. This study provides first evidence of feasibility of hyperspectral imaging as a potentially helpful contact-free organ viability assessment tool during liver NMP.
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Affiliation(s)
- Margot Fodor
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Lukas Lanser
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Julia Hofmann
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Giorgi Otarashvili
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Marlene Pühringer
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Benno Cardini
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Rupert Oberhuber
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Thomas Resch
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Annemarie Weissenbacher
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Manuel Maglione
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Christian Margreiter
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Philipp Zelger
- Department for Hearing, Speech, and Voice Disorders, Medical University of Innsbruck, Innsbruck, Austria
| | - Johannes D. Pallua
- University Hospital for Orthopedics and Traumatology, Medical University of Innsbruck, Innsbruck, Austria
| | - Dietmar Öfner
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Robert Sucher
- Department of Visceral, Transplant, Thoracic and Vascular Surgery, Leipzig University Clinic, Leipzig, Germany
| | - Theresa Hautz
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria
| | - Stefan Schneeberger
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria,OrganLife, Organ Regeneration Center of Excellence, Innsbruck, Austria,*Correspondence: Stefan Schneeberger,
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Pfahl A, Köhler H, Thomaßen MT, Maktabi M, Bloße AM, Mehdorn M, Lyros O, Moulla Y, Niebisch S, Jansen-Winkeln B, Chalopin C, Gockel I. Video: Clinical evaluation of a laparoscopic hyperspectral imaging system. Surg Endosc 2022; 36:7794-7799. [PMID: 35546207 PMCID: PMC9485189 DOI: 10.1007/s00464-022-09282-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 04/16/2022] [Indexed: 11/30/2022]
Abstract
Background Hyperspectral imaging (HSI) during surgical procedures is a new method for perfusion quantification and tissue discrimination. Its use has been limited to open surgery due to large camera sizes, missing color video, or long acquisition times. A hand-held, laparoscopic hyperspectral camera has been developed now to overcome those disadvantages and evaluated clinically for the first time. Methods In a clinical evaluation study, gastrointestinal resectates of ten cancer patients were investigated using the laparoscopic hyperspectral camera. Reference data from corresponding anatomical regions were acquired with a clinically approved HSI system. An image registration process was executed that allowed for pixel-wise comparisons of spectral data and parameter images (StO2: oxygen saturation of tissue, NIR PI: near-infrared perfusion index, OHI: organ hemoglobin index, TWI: tissue water index) provided by both camera systems. The mean absolute error (MAE) and root mean square error (RMSE) served for the quantitative evaluations. Spearman’s rank correlation between factors related to the study design like the time of spectral white balancing and MAE, respectively RMSE, was calculated. Results The obtained mean MAEs between the TIVITA® Tissue and the laparoscopic hyperspectral system resulted in StO2: 11% ± 7%, NIR PI: 14±3, OHI: 14± 5, and TWI: 10 ± 2. The mean RMSE between both systems was 0.1±0.03 from 500 to 750 nm and 0.15 ±0.06 from 750 to 1000 nm. Spearman’s rank correlation coefficients showed no significant correlation between MAE or RMSE and influencing factors related to the study design. Conclusion Qualitatively, parameter images of the laparoscopic system corresponded to those of the system for open surgery. Quantitative deviations were attributed to technical differences rather than the study design. Limitations of the presented study are addressed in current large-scale in vivo trials. Supplementary Information The online version contains supplementary material available at 10.1007/s00464-022-09282-y.
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Affiliation(s)
- Annekatrin Pfahl
- Innovation Center Computer Assisted Surgery (ICCAS), Faculty of Medicine, Leipzig University, Semmelweisstr. 14, 04103, Leipzig, Germany.
| | - Hannes Köhler
- Innovation Center Computer Assisted Surgery (ICCAS), Faculty of Medicine, Leipzig University, Semmelweisstr. 14, 04103, Leipzig, Germany
| | - Madeleine T Thomaßen
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany
| | - Marianne Maktabi
- Innovation Center Computer Assisted Surgery (ICCAS), Faculty of Medicine, Leipzig University, Semmelweisstr. 14, 04103, Leipzig, Germany
| | - Albrecht M Bloße
- Innovation Center Computer Assisted Surgery (ICCAS), Faculty of Medicine, Leipzig University, Semmelweisstr. 14, 04103, Leipzig, Germany
| | - Matthias Mehdorn
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany
| | - Orestis Lyros
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany
| | - Yusef Moulla
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany
| | - Stefan Niebisch
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany
| | - Boris Jansen-Winkeln
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany.,Department of General, Visceral, Thoracic, and Vascular Surgery, Klinikum St. Georg, Leipzig, Germany
| | - Claire Chalopin
- Innovation Center Computer Assisted Surgery (ICCAS), Faculty of Medicine, Leipzig University, Semmelweisstr. 14, 04103, Leipzig, Germany
| | - Ines Gockel
- Department of Visceral, Transplant, Thoracic, and Vascular Surgery, University Hospital of Leipzig, Leipzig, Germany
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Sommer F, Sun B, Fischer J, Goldammer M, Thiele C, Malberg H, Markgraf W. Hyperspectral Imaging during Normothermic Machine Perfusion—A Functional Classification of Ex Vivo Kidneys Based on Convolutional Neural Networks. Biomedicines 2022; 10:biomedicines10020397. [PMID: 35203605 PMCID: PMC8962340 DOI: 10.3390/biomedicines10020397] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/28/2022] [Accepted: 01/30/2022] [Indexed: 12/18/2022] Open
Abstract
Facing an ongoing organ shortage in transplant medicine, strategies to increase the use of organs from marginal donors by objective organ assessment are being fostered. In this context, normothermic machine perfusion provides a platform for ex vivo organ evaluation during preservation. Consequently, analytical tools are emerging to determine organ quality. In this study, hyperspectral imaging (HSI) in the wavelength range of 550–995 nm was applied. Classification of 26 kidneys based on HSI was established using KidneyResNet, a convolutional neural network (CNN) based on the ResNet-18 architecture, to predict inulin clearance behavior. HSI preprocessing steps were implemented, including automated region of interest (ROI) selection, before executing the KidneyResNet algorithm. Training parameters and augmentation methods were investigated concerning their influence on the prediction. When classifying individual ROIs, the optimized KidneyResNet model achieved 84% and 62% accuracy in the validation and test set, respectively. With a majority decision on all ROIs of a kidney, the accuracy increased to 96% (validation set) and 100% (test set). These results demonstrate the feasibility of HSI in combination with KidneyResNet for non-invasive prediction of ex vivo kidney function. This knowledge of preoperative renal quality may support the organ acceptance decision.
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