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Experimental and Clinical... Mar 2021Chronic kidney disease is the most common type of organ failure worldwide, with a prevalence of 13.4% for all stages. Organ transplant is the only curative option for... (Review)
Review
Chronic kidney disease is the most common type of organ failure worldwide, with a prevalence of 13.4% for all stages. Organ transplant is the only curative option for end-stage kidney failure. However, the shortage of organ donors remains a major obstacle in organ transplant, with donation after circulatory death being the most viable path to increasing the donor pool. The circumstances that surround this type of donation are different from donation after brain death, namely concerning warm ischemia times, which are longer and may preclude a successful transplant. This article describes the pathophysiology of warm ischemia and summarizes recent developments in technological and methodological practices that mitigate the mechanisms of warm ischemia. Anoxia, mitochondrial dysfunction, calcium overload, oxidative and nitrosative stress, immune response, and no reflow are the main mechanisms by which ischemia leads to cell death and organ dysfunction. In situ oxygenated recirculation, abdominal normothermic organ recirculation, abdominal hypothermic organ recirculation, and ex vivo machine perfusion ensure continued organ perfusion and prevent prolonged warm ischemia in organ donation. These practices, coupled with optimizations in the identification and assessment of potential donors after circulatory death, may lead to a significant increase in the number and success rates of organ transplant worldwide.
Topics: Death; Humans; Tissue Donors; Warm Ischemia
PubMed: 32799784
DOI: 10.6002/ect.2020.0081 -
Urologic Oncology 2011At the 11th Annual Meeting of the Society of Urologic Oncology (SUO), an expert panel discussed the importance of warm ischemia time on renal function during partial... (Review)
Review
OBJECTIVE
At the 11th Annual Meeting of the Society of Urologic Oncology (SUO), an expert panel discussed the importance of warm ischemia time on renal function during partial nephrectomy. The position of this manuscript is that every minute of warm ischemia time has a deleterious effect on renal function outcomes following partial nephrectomy.
MATERIALS AND METHODS
The presentation was derived from a review of the published urologic, nephrology, and transplant literature related to warm ischemia time and renal function outcomes.
RESULTS
There exist numerous clinical models to study the effects of warm ischemia on renal function. These include the bilateral kidney, unilateral partial nephrectomy, solitary kidney partial nephrectomy, and transplant kidney model. Each of these models provides evidence for minimizing warm ischemia time to prevent acute renal failure, chronic kidney disease, and end stage renal failure. In the best available model, solitary kidney partial nephrectomy, each minute of warm ischemia was found to be associated with a 6% increased risk of acute renal failure, 7% increased risk of acute-onset end stage renal disease (ESRD), and 4% increased risk of new-onset ESRD while controlling for preoperative renal function, tumor size, and surgical approach.
CONCLUSIONS
There is ample evidence, consistent across multiple human kidney models, supporting the potentially deleterious renal effects of warm ischemia during partial nephrectomy. There does not appear to be a known safe threshold of warm ischemia since each minute sequentially contributes to the risk of developing acute kidney injury and renal function decline. Ultimate renal function following PN is dependent on the "3 Qs": quality (renal function prior to surgery), quantity (renal parenchyma preserved during surgery), and quickness (ischemia time).
Topics: Humans; Nephrectomy; Warm Ischemia
PubMed: 22078406
DOI: 10.1016/j.urolonc.2011.02.015 -
Transplantation Jun 2021Donation after circulatory death (DCD) grafts are commonly used in liver transplantation. Attributable to the additional ischemic event during the donor warm ischemia... (Review)
Review
Donation after circulatory death (DCD) grafts are commonly used in liver transplantation. Attributable to the additional ischemic event during the donor warm ischemia time (DWIT), DCD grafts carry an increased risk for severe ischemia/reperfusion injury and postoperative complications, such as ischemic cholangiopathy. The actual ischemia during DWIT depends on the course of vital parameters after withdrawal of life support and varies widely between donors. The ischemic period (functional DWIT) starts when either Spo2 or blood pressure drop below a certain point and lasts until the start of cold perfusion during organ retrieval. Over the years, multiple definitions and thresholds of functional DWIT duration have been used. The International Liver Transplantation Society organized a Consensus Conference on DCD, Liver Preservation, and Machine Perfusion on January 31, 2020 in Venice, Italy. The aim of this conference was to reach consensus about various aspects of DCD liver transplantation in context of currently available evidence. Here we present the recommendations with regards to the definitions used for DWIT and functional DWIT, the importance of vital parameters after withdrawal of life support, and acceptable thresholds of duration of functional DWIT to proceed with liver transplantation.
Topics: Hepatectomy; Humans; Liver Transplantation; Organ Preservation; Perfusion; Time Factors; Tissue Donors; Tissue Survival; Tissue and Organ Harvesting; Warm Ischemia
PubMed: 34048418
DOI: 10.1097/TP.0000000000003819 -
Liver Transplantation : Official... Nov 2023The donor operation and the hemodynamics during declaration resulting in donor warm ischemia time have been linked to the outcomes in donation after circulatory death... (Review)
Review
Oxygen saturation during donor warm ischemia time and outcome of donation after circulatory death (DCD) liver transplantation with static cold storage: A review of 1114 cases.
The donor operation and the hemodynamics during declaration resulting in donor warm ischemia time have been linked to the outcomes in donation after circulatory death (DCD) liver transplantation (LT). Scrutiny of the donor hemodynamics at the time of withdrawal of life support concluded that a functional donor warm ischemia time may be associated with LT graft failure. Unfortunately, the definition for functional donor warm ischemia time has not reached a consensus-but has almost always incorporated time spent in a hypoxic state. Herein, we reviewed 1114 DCD LT cases performed at the 20 highest volume centers during 2014 and 2018. Donor hypoxia began within 3 minutes of withdrawal of life support for 60% of cases and within 10 minutes for 95% of cases. Graft survival was 88.3% at 1 year and 80.3% at 3 years. Scrutinizing the time spent under hypoxic conditions (oxygen saturation ≤ 80%) during the withdrawal of life support, we found an increasing risk of graft failure as hypoxic time increased from 0 to 16 minutes. After 16 minutes and up to 50 minutes, we did not find any increased risk of graft failure. In conclusion, after 16 minutes of time in hypoxia, the risk of graft failure in DCD LT did not increase. The current evidence suggests that an over-reliance on hypoxia time may lead to an unnecessary increase in DCD liver discard and may not be as useful for predicting graft loss after LT.
Topics: Humans; Warm Ischemia; Liver Transplantation; Oxygen Saturation; Donor Selection; Risk Factors; Tissue Donors; Hypoxia; Graft Survival; Retrospective Studies; Tissue and Organ Procurement; Death
PubMed: 37076131
DOI: 10.1097/LVT.0000000000000162 -
Experimental and Clinical... Feb 2020
Topics: Anastomosis, Surgical; Delayed Graft Function; Graft Survival; Humans; Kidney Transplantation; Treatment Outcome; Warm Ischemia
PubMed: 32170860
DOI: 10.6002/ect.2019.0317 -
JNMA; Journal of the Nepal Medical... Jun 2023In renal transplantation, warm ischemia time is the interval from the removal of a procured kidney from ice storage to initiating graft reperfusion. Successful kidney...
INTRODUCTION
In renal transplantation, warm ischemia time is the interval from the removal of a procured kidney from ice storage to initiating graft reperfusion. Successful kidney transplantation depends on warm ischemia time. The study aims to find the mean warm ischemia time among kidney transplant patients in a tertiary care centre.
METHODS
This descriptive cross-sectional study was conducted among kidney transplant patients in a tertiary care centre. Data from 15 December 2012 to 15 October 2022 were collected between 1 December 2022 to 4 January 2023 from the hospital records. Ethical approval was taken from the Nepal Health Research Council (Reference number: 1341). All first-time living-related kidney transplant recipients were included in the study. All the patients undergoing kidney transplants from brain-dead donors were excluded from the study. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.
RESULTS
Among 230 patients, the mean warm ischemia time was 35.45±7.35 min. The mean first warm ischemia time was 4.28±2.05 min and the mean second warm ischemia time was 31.27±7.04 min. The mean age of the recipients was 35.14±10.49 years (range 14-64), of which 173 (75.20%) were male and 57 (24.80%) were female.
CONCLUSIONS
The mean warm ischemia time among kidney transplant patients in a tertiary care centre was similar to the studies done in similar settings.
KEYWORDS
kidney transplantation; prevalence; warm ischemia.
Topics: Warm Ischemia; Kidney Transplantation; Tertiary Care Centers; Cross-Sectional Studies; Humans; Living Donors; Adolescent; Young Adult; Adult; Middle Aged; Male; Female
PubMed: 37464848
DOI: 10.31729/jnma.8190 -
Minerva Urology and Nephrology Apr 2022The impact of warm ischemia time (WIT) on renal functional recovery remains controversial. We examined the length of WIT>30 min on the long-term renal function following...
BACKGROUND
The impact of warm ischemia time (WIT) on renal functional recovery remains controversial. We examined the length of WIT>30 min on the long-term renal function following on-clamp partial nephrectomy (PN).
METHODS
Data from 23 centers for patients undergoing on-clamp PN between 2000 and 2018 were analyzed. We included patients with two kidneys, single tumor, cT1, minimum 1-year follow-up, and preoperative eGFR≥60 mL/min/1.73m. Patients were divided into two groups according to WIT length: group I "WIT≤30 min" and group II "WIT>30 min." A propensity-score matched analysis (1:1 match) was performed to eliminate potential confounding factors between groups. We compared eGFR values, eGFR (%) preservation, eGFR decline, events of chronic kidney disease (CKD) upgrading, and CKD-free progression rates between both groups. Cox regression analysis evaluated WIT impact on upgrading of CKD stages.
RESULTS
The primary cohort consisted of 3526 patients: group I (N.=2868) and group II (N.=658). After matching the final cohort consisted of 344 patients in each group. At last follow-up, there were no significant differences in median eGFR values at 1, 3, 5, and 10 years (P>0.05) between the matched groups. In addition, the median eGFR (%) preservation and absolute eGFR change were similar (89% in group I vs. 87% in group II, P=0.638) and (-10 in group I vs. -11 in group II, P=0.577), respectively. The 5 years new-onset CKD-free progression rates were comparable in the non-matched groups (79% in group I vs. 81% in group II, log-rank, P=0.763) and the matched groups (78.8% in group I vs. 76.3% in group II, log-rank, P=0.905). Univariable Cox regression analysis showed that WIT>30 min was not a predictor of overall CKD upgrading (HR:0.953, 95%CI 0.829-1.094, P=0.764) nor upgrading into CKD stage ≥III (HR:0.972, 95%CI 0.805-1.173, P=0.764). Retrospective design is a limitation of our study.
CONCLUSIONS
Our analysis based on a large multicenter international cohort study suggests that WIT length during PN has no effect on the long-term renal function outcomes in patients having two kidneys and preoperative eGFR≥60 mL/min/1.73m.
Topics: Cohort Studies; Glomerular Filtration Rate; Humans; Kidney Neoplasms; Nephrectomy; Retrospective Studies; Warm Ischemia
PubMed: 34308610
DOI: 10.23736/S2724-6051.21.04466-9 -
American Journal of Transplantation :... May 2022Donation after circulatory death (DCD) represents a promising opportunity to overcome the relative shortage of donors for heart transplantation. However, the necessary...
Donation after circulatory death (DCD) represents a promising opportunity to overcome the relative shortage of donors for heart transplantation. However, the necessary period of warm ischemia is a concern. This study aims to determine the critical warm ischemia time based on in vivo biochemical changes. Sixteen DCD non-cardiac donors, without cardiovascular disease, underwent serial endomyocardial biopsies immediately before withdrawal of life-sustaining therapy (WLST), at circulatory arrest (CA) and every 2 min thereafter. Samples were processed into representative pools to assess calcium homeostasis, mitochondrial function and cellular viability. Compared to baseline, no significant deterioration was observed in any studied parameter at the time of CA (median: 9 min; IQR: 7-13 min; range: 4-19 min). Ten min after CA, phosphorylation of cAMP-dependent protein kinase-A on Thr197 and SERCA2 decreased markedly; and parallelly, mitochondrial complex II and IV activities decreased, and caspase 3/7 activity raised significantly. These results did not differ when donors with higher WLST to CA times (≥9 min) were analyzed separately. In human cardiomyocytes, the period from WLST to CA and the first 10 min after CA were not associated with a significant compromise in cellular function or viability. These findings may help to incorporate DCD into heart transplant programs.
Topics: Death; Heart; Heart Arrest; Heart Transplantation; Humans; Perfusion; Tissue Donors; Tissue and Organ Procurement; Warm Ischemia
PubMed: 35114047
DOI: 10.1111/ajt.16987 -
Texas Heart Institute Journal Feb 2019
Review
Topics: Extracorporeal Circulation; Graft Rejection; Graft Survival; Humans; Lung Transplantation; Perfusion; Warm Ischemia
PubMed: 30833853
DOI: 10.14503/THIJ-18-6764 -
World Journal of Urology Apr 2023The lack of a reliable and reproducible technique to ensure a constantly low temperature of the graft during kidney transplantation (KT) may be a cause of renal... (Review)
Review
PURPOSE
The lack of a reliable and reproducible technique to ensure a constantly low temperature of the graft during kidney transplantation (KT) may be a cause of renal nonfunction. The aim of this review was to assess all the methods and devices available to ensure hypothermia during vascular anastomosis in KT.
METHODS
A literature search was conducted through May 2022 using PubMed/Medline, Cochrane Library, Embase and Web of Science databases. Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed to identify eligible studies. The review protocol was registered on PROSPERO (CRD42022326550).
RESULTS
A total of 20 studies reporting on four hypothermia techniques met our inclusion criteria. Simple instillation of cold serum is not sufficient, the graft reaching up to 33 ℃ at the end of warm ischemia time (WIT). Plastic bags filled with ice slush have questionable efficiency. The use of a gauze jacket filled with ice-slush was reported in 12/20 studies. It ensures a graft temperature up to 20.3 ℃ at the end of WIT. Some concerns have been linked to potentially inhomogeneous parenchymal cooling and secondary ileus. Novel devices with continuous flow of ice-cold solution around the graft might overcome these limitations, showing a renal temperature below 20 ℃ at all times during KT.
CONCLUSION
The gauze filled with ice slush is the most common technique, but several aspects can be improved. Novel devices in the form of cold-ischemia jackets can ensure a lower and more stable temperature of the graft during KT, leading to higher efficiency and reproducibility.
Topics: Humans; Kidney Transplantation; Warm Ischemia; Hypothermia, Induced; Hypothermia; Ice; Reproducibility of Results
PubMed: 36826486
DOI: 10.1007/s00345-023-04328-9