Indocyanine green fluorescence quantification during normothermic ex situ perfusion for the assessment of porcine liver grafts after circulatory death.

Current graft evaluation during normothermic ex situ liver perfusion lacks real-time parameters for predicting posttransplant hepatocyte and biliary function. Indocyanine green (ICG) imaging has been widely used in liver surgery, enabling the visualization of hepatic uptake and excretion through bile using near-infrared light. In this research, porcine livers under various ischemic conditions were examined during a 5-hour normothermic ex situ liver perfusion procedure, introducing ICG at 1 hour through the hepatic artery. These conditions included livers from heart-beating donors, donation after circulatory death (DCD) with warm ischemic durations of 60 minutes (DCD60) and 120 minutes (DCD120), as well as interventions utilizing tissue plasminogen activator in DCD120 cases (each n = 5). Distinct hepatic fluorescence patterns correlated with different degrees of ischemic injury ( p = 0.01). Low ICG uptake in the parenchyma (less than 40% of maximum intensity) was more prevalent in DCD120 (21.4%) compared to heart-beating donors (6.2%, p = 0.06) and DCD60 (3.0%, p = 0.02). Moreover, ICG clearance from 60 minutes to 240 minutes was significantly higher in heart-beating donors (69.3%) than in DCD60 (17.5%, p < 0.001) and DCD120 (32.1%, p = 0.01). Furthermore, thrombolytic intervention using tissue plasminogen activator in DCD120 resulted in noteworthy outcomes, including significantly reduced ALP levels ( p = 0.04) and improved ICG clearance ( p = 0.02) with a trend toward mitigating fibrin deposition similar to DCD60, as well as enhancements in bile production ( p = 0.09). In conclusion, ICG fluorescence imaging during normothermic ex situ liver perfusion provides real-time classification of hepatic vascular and biliary injuries, offering valuable insights for the more accurate selection and postintervention evaluation of marginal livers in transplantation.

Pursuing living donor liver transplantation improves outcomes of patients with autoimmune liver diseases: An intention-to-treat analysis.

Living donor liver transplantation (LDLT) offers the opportunity to decrease waitlist time and mortality for patients with autoimmune liver disease (AILD), autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. We compared the survival of patients with a potential living donor (pLDLT) on the waitlist versus no potential living donor (pDDLT) on an intention-to-treat basis. Our retrospective cohort study investigated adults with AILD listed for a liver transplant in our program between 2000 and 2021. The pLDLT group comprised recipients with a potential living donor. Otherwise, they were included in the pDDLT group. Intention-to-treat survival was assessed from the time of listing. Of the 533 patients included, 244 (43.8%) had a potential living donor. Waitlist dropout was higher for the pDDLT groups among all AILDs (pDDLT 85 [29.4%] vs. pLDLT 9 [3.7%], p < 0.001). The 1-, 3-, and 5-year intention-to-treat survival rates were higher for pLDLT versus pDDLT among all AILDs (95.7% vs. 78.1%, 89.0% vs. 70.1%, and 87.1% vs. 65.5%, p < 0.001). After adjusting for covariates, pLDLT was associated with a 38% reduction in the risk of death among the AILD cohort (HR: 0.62, 95% CI: 0.42-0.93 [ p <0.05]), and 60% among the primary sclerosing cholangitis cohort (HR: 0.40, 95% CI: 0.22-0.74 [ p <0.05]). There were no differences in the 1-, 3-, and 5-year post-transplant survival between LDLT and DDLT (AILD: 95.6% vs. 92.1%, 89.9% vs. 89.4%, and 89.1% vs. 87.1%, p =0.41). This was consistent after adjusting for covariates (HR: 0.97, 95% CI: 0.56-1.68 [ p >0.9]). Our study suggests that having a potential living donor could decrease the risk of death in patients with primary sclerosing cholangitis on the waitlist. Importantly, the post-transplant outcomes in this population are similar between the LDLT and DDLT groups.

Trajectories of patients relisted for liver transplantation.

INTRODUCTION AND OBJECTIVES: Recurrent cirrhosis complicates 10-30% of Liver transplants (LT) and can lead to consideration for re-transplantation. We evaluated the trajectories of relisted versus primary listed patients on the waitlist using a competing risk framework. MATERIALS AND METHODS: We retrospectively examined 1,912 patients listed for LT at our centre between from 2012 to 2020. Cox proportional hazard models were used to assess overall survival (OS) by listing type and competing risk analysis Fine-Gray models were used to assess cumulative incidence of transplant by listing type. RESULTS: 1,731 patients were included (104 relisted). 44.2% of relisted patients received exception points vs. 19.8% of primary listed patients (p<0.001). Patients relisted without exceptions, representing those with graft cirrhosis, had the worst OS (HR: 4.17, 95%CI 2.63 - 6.67, p=<0.0001) and lowest instantaneous rate of transplant (HR: 0.56, 95%CI 0.38 - 0.83, p=0.006) than primary listed with exception points. On multivariate analysis listing type, height, bilirubin and INR were associated with cumulative incidence of transplant, while listing type, bilirubin, INR, sodium, creatinine were associated with OS. Within relisted patients, there was a trend towards higher mortality (HR: 1.79, 95%CI 0.91 - 3.52, p=0.08) and low transplant incidence (HR: 0.51, 95%CI 0.22 - 1.15, p=0.07) for graft cirrhosis vs other relisting indications. CONCLUSIONS: Patients relisted for LT are carefully curated and comprise a minority of the waitlist population. Despite their younger age, they have worse liver/kidney function, poor waitlist survival, and decreased transplant incidence suggesting the need for early relisting, while considering standardized exception points.

Impact of early surgical complications on kidney transplant outcomes.

BACKGROUND: Kidney transplantation (KT) improves clinical outcomes of patients with end stage renal disease. Little has been reported on the impact of early post-operative surgical complications (SC) on long-term clinical outcomes following KT. We sought to determine the impact of vascular complications, urological complications, surgical site complications, and peri-graft collections within 30 days of transplantation on patient survival, graft function, and hospital readmissions. METHODS: We conducted a single-centre, observational cohort study examining adult patients (≥ 18 years) who received a kidney transplant from living and deceased donors between January 1st, 2005 and December 31st, 2015 with follow-up until December 31st, 2016 (n = 1,334). Univariable and multivariable analyses were performed with Cox proportional hazards models to analyze the outcomes of SC in the early post-operative period after KT. RESULTS: The cumulative probability of SC within 30 days of transplant was 25%, the most common SC being peri-graft collections (66.8%). Multivariable analyses showed significant relationships between Clavien Grade 1 SC and death with graft function (HR 1.78 [95% CI: 1.11, 2.86]), and between Clavien Grades 3 to 4 and hospital readmissions (HR 1.95 [95% CI: 1.37, 2.77]). CONCLUSIONS: Early SC following KT are common and have a significant influence on long-term patient outcomes.

Medical Assistance in Dying (MAiD) as a Source of Liver Grafts: Honouring the Ultimate Gift.

OBJECTIVE: To report the clinical outcomes of liver transplants from donors after medical assistance in dying (MAiD) versus donors after cardiac death (DCD) and deceased brain death (DBD). SUMMARY BACKGROUND DATA: In North America, the number of patients needing liver transplants exceeds the number of available donors. In 2016, MAiD was legalized in Canada. METHODS: All patients undergoing deceased donor liver transplantation at Toronto General Hospital between 2016 and 2021 were included in the study. Recipient perioperative and postoperative variables and donor physiological variables were compared among 3 groups. RESULTS: Eight hundred seven patients underwent deceased donor liver transplantation during the study period, including DBD (n=719; 89%), DCD (n=77; 9.5%), and MAiD (n=11; 1.4%). The overall incidence of biliary complications was 6.9% (n=56), the most common being strictures (n=55;6.8%), highest among the MAiD recipients [5.8% (DBD) vs. 14.2% (DCD) vs. 18.2% (MAiD); P =0.008]. There was no significant difference in 1 year (98.4% vs. 96.4% vs. 100%) and 3-year (89.3% vs. 88.7% vs. 100%) ( P =0.56) patient survival among the 3 groups. The 1- and 3- year graft survival rates were comparable (96.2% vs. 95.2% vs. 100% and 92.5% vs. 91% vs. 100%; P =0.37). CONCLUSION: With expected physiological hemodynamic challenges among MAiD and DCD compared with DBD donors, a higher rate of biliary complications was observed in MAiD donors, with no significant difference noted in short-and long-term graft outcomes among the 3 groups. While ethical challenges persist, good initial results suggest that MAiD donors can be safely used in liver transplantation, with results comparable with other established forms of donation.

Normothermic Ex Vivo Machine Perfusion of Discarded Human Pancreas Allografts: A Feasibility Study.

Pancreas transplantation is the only curative treatment for patients with complicated diabetes, and organ shortage is a common and increasing problem. Strategies to expand the donor pool are needed, and normothermic ex vivo perfusion of the pancreas has the potential to test and repair grafts before implantation. Between January 2021 and April 2022, six human pancreases, declined for transplantation or islet isolation, were perfused using a previously established method by our group. All 6 cases were successfully perfused for 4 h, with minimal edema. The mean age of the donors was 44.16 ± 13.8 years. Five grafts were obtained from neurological death donors, and one was obtained from a donation after cardiac death. The mean glucose and lactate levels decreased throughout perfusion and insulin levels increased. All 6 grafts were metabolically active during perfusion and histopathology showed minimal tissue injury and no edema. Human normothermic ex vivo perfusion of the pancreas is feasible and safe and has the potential to expand the donor pool. Future studies will focus on tests and biomarkers for the assessment of grafts.

Normothermic Ex-vivo Kidney Perfusion in a Porcine Auto-Transplantation Model Preserves the Expression of Key Mitochondrial Proteins: An Unbiased Proteomics Analysis.

Normothermic ex-vivo kidney perfusion (NEVKP) results in significantly improved graft function in porcine auto-transplant models of donation after circulatory death injury compared with static cold storage (SCS); however, the molecular mechanisms underlying these beneficial effects remain unclear. We performed an unbiased proteomics analysis of 28 kidney biopsies obtained at three time points from pig kidneys subjected to 30 min of warm ischemia, followed by 8 h of NEVKP or SCS, and auto-transplantation. 70/6593 proteins quantified were differentially expressed between NEVKP and SCS groups (false discovery rate < 0.05). Proteins increased in NEVKP mediated key metabolic processes including fatty acid ß-oxidation, the tricarboxylic acid cycle, and oxidative phosphorylation. Comparison of our findings with external datasets of ischemia-reperfusion and other models of kidney injury confirmed that 47 of our proteins represent a common signature of kidney injury reversed or attenuated by NEVKP. We validated key metabolic proteins (electron transfer flavoprotein subunit beta and carnitine O-palmitoyltransferase 2, mitochondrial) by immunoblotting. Transcription factor databases identified members of the peroxisome proliferator-activated receptors (PPAR) family of transcription factors as the upstream regulators of our dataset, and we confirmed increased expression of PPARA, PPARD, and RXRA in NEVKP with reverse transcription polymerase chain reaction. The proteome-level changes observed in NEVKP mediate critical metabolic pathways. These effects may be coordinated by PPAR-family transcription factors and may represent novel therapeutic targets in ischemia-reperfusion injury.

The epidemiology of early deep vein thrombosis in kidney transplant recipients.

BACKGROUND: Because kidney transplant recipients may be at increased risk for deep vein thrombosis (DVT) following transplantation, we investigated the incidence, risk factors, treatments and outcomes of early DVT among kidney transplant recipients. METHODS: An observational, single-centre cohort study was conducted among adult kidney transplant recipients from Jan. 1, 2005, to Dec. 31, 2016 with 1-year followup. Time to DVT was assessed using the Kaplan-Meier method. Cox proportional hazards and linear regression models were used to analyze risk factors for and outcomes of DVT. RESULTS: The cumulative incidence of DVT was 4.25% at 3 months after transplant. In multivariable analysis, the use of depleting induction agents (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.05-4.35]), white recipient race (HR 1.84. 95% CI 1.08-3.12), the use of kidneys from expanded criteria donors (HR 2.13, 95% CI 1.05-4.32) and lower recipient body mass index (HR 0.95, 95% CI 0.91-1.00) increased the risk for early DVT. Peritransplant DVT prophylaxis was not associated with early DVT. Early DVT was not associated with reduced graft function, death, graft failure or first hospital readmission. CONCLUSION: Risk factors for early DVT in our cohort of kidney transplant recipients included white recipient race, use of depleting agents, lower recipient body mass index and use of expanded criteria donors. As practice patterns of donor and recipient selection in kidney transplantation evolve, the results of this study may aid in perioperative risk assessments and decision-making about the use of DVT prophylaxis.

Should advanced donor age be a deterrent in the utilization of grafts from donation after cardiac death in deceased donor liver transplantation? The Toronto experience.

BACKGROUND: Advanced donor age paired with donation after cardiac death (DCD) increases the risk of transplantation, precluding widespread use of grafts from such donors worldwide. Our aim was to analyze outcomes of liver transplantation using grafts from older DCD donors and donation after brain death (DBD) donors. METHODS: Patients who underwent liver transplantation using grafts from deceased donors between January 2016 and December 2021 were included in the study. Short-and long-term outcomes were analyzed for 4 groups of patients: those who received DCD and DBD grafts from younger (< 50 yr) and older (≥ 50 yr) donors. RESULTS: Of the 807 patients included in the analysis, 44.7% (n = 361) of grafts were received from older donors, with grafts for older DCD donors comprising 4.7% of the total cohort (n = 38). Patients who received grafts from older donors had a lower incidence of biliary strictures than those who received grafts from younger donors (7.9% v. 20.0% for DCD donation, p = 0.14, and 4.9% v. 6.8% for DBD donation, p = 0.34), with a significantly lower incidence of ischemic-type biliary strictures in patients who received grafts from older versus younger DCD donors (2.6% v. 18.0%, p = 0.04). There was no difference in 1- and 3-year graft survival rates among patients who received grafts from older and younger DCD donors (92.1% v. 90.8% and 80.2% v. 80.9%, respectively) and those who received grafts from older and younger DBD donors (90.1% v. 93.2% and 85.3% v. 84.4%, respectively) (p = 0.85). Pretransplantation admission to the intensive care unit (hazard ratio [HR] 9.041, p < 0.001) and nonalcoholic steatohepatitis (HR 2.197, p = 0.02) were found to significantly affect survival of grafts from older donors. CONCLUSION: Donor age alone should not be the criterion to determine the acceptability of grafts in liver transplantation. With careful selection criteria, older DCD donors could make a valuable contribution to expanding the liver donor pool, with grafts that produce comparable results to those obtained with standard-criteria grafts.

Biliary Metabolome Profiling for Evaluation of Liver Metabolism and Biliary Tract Function Related to Organ Preservation Method and Degree of Ischemia in a Porcine Model.

The development of surgical techniques, immunosuppressive strategies and new organ preservation methods have meant that transplant centers have to face the problem of an insufficient number of organs for transplantation concerning the constantly growing demand. Therefore, using organs from expanded criteria donors and developing new analytical solutions to find parameters or compounds that would allow a more efficient assessment of organ quality before transplantation are options for meeting this challenge. This study proposed bile metabolomic analysis to evaluate liver metabolism and biliary tract function depending on the organ preservation method and degree of warm ischemia time. The analyses were performed on solid-phase microextraction-prepared bile samples from porcine model donors with mild (heart beating donor [HBD]) and moderate warm ischemia (donation after circulatory death [DCD]) grafts subjected to static cold storage (SCS) or normothermic ex vivo liver perfusion (NEVLP) before transplantation. Bile produced in the SCS-preserved livers was characterized by increased levels of metabolites such as chenodeoxycholic acid, arachidonic acid and 5S-hydroxyeicosatetraeonic acid, as well as saturated and monounsaturated lysophosphatidylcholines (LPC). Such changes may be associated with differences in the bile acid synthesis pathways and organ inflammation. Moreover, it has been shown that NEVLP reduced the negative effect of ischemia on organ function. A linear relationship was observed between levels of lipids from the LPC group and the time of organ ischemia. This study identified metabolites worth considering as potential markers of changes occurring in preserved grafts.

Normothermic ex situ pancreas perfusion for the preservation of porcine pancreas grafts.

Pancreas transplantation improves and extends the life of patients with insulin-dependent diabetes. Pancreata from extended criteria donors have been increasingly used due to the scarcity of available grafts. Normothermic ex situ pancreas perfusion (NESPP) can keep grafts metabolically active, potentially allowing for assessment and organ repair, and could improve outcomes of marginal grafts. A novel NESPP technique was developed and tested. Porcine pancreata were removed after a short period of warm ischemia and subjected to 6 h of NESPP. Perfusion parameters, potential graft assessment markers and graft injury were measured. Next, pancreata subjected to 3 h of NESPP were transplanted and animals were followed for up to 3 days. Graft function and injury post-transplantation were evaluated. Using this novel system of perfusion, pancreata were perfused for an extended period of time with minimal edema. Histology at the end of perfusion showed intact islet cells with only mild signs of tissue injury. NESPP transplanted grafts showed immediate function after transplantation, with glucose levels in normal range. NESPP maintains a physiologic environment and excellent graft function without causing significant graft injury. Porcine pancreas transplantation is feasible and allows for in vivo graft assessment of pancreas function and injury after NESPP.

Results of Early Transplantation for Alcohol-Related Cirrhosis: Integrated Addiction Treatment With Low Rate of Relapse.

BACKGROUND & AIMS: In 2018, our team initiated a prospective pilot program to challenge the paradigm of the "6-month rule" of abstinence for patients with alcohol-related liver disease (ALD) requiring transplant. Our pilot involved an in-depth examination of patients' alcohol use, social support, and psychiatric comorbidity, as well as the provision of pre- and post-transplantation addiction treatment. METHODS: Patients with ALD were assessed for inclusion in the pilot by a multidisciplinary team. Relapse prevention therapy was provided directly to all patients deemed to meet the program's inclusion criteria. Random biomarker testing for alcohol was used pre and post transplantation. RESULTS: We received 703 referrals from May 1, 2018 to October 31, 2020. After fulfilling the program's criteria, 101 patients (14%) were listed for transplantation and 44 (6.2%) received transplants. There were no significant differences in survival rates between those receiving transplants through the pilot program compared with a control group with more than 6 months of abstinence (P = .07). Three patients returned to alcohol use during an average post-transplantation follow-up period of 339 days. In a multivariate analysis, younger age and lower Model for End-Stage Liver Disease scores at listing were associated with an increased likelihood of a return to alcohol use (P < .05); length of abstinence was not a predictor. CONCLUSIONS: Our prospective program provided direct monitoring and relapse prevention treatment for patients with ALD and with less than 6 months of abstinence and resulted in a reduction of post-transplantation return to drinking. This pilot study provides a framework for the future of more equitable transplant care.

Superior Long-Term Outcomes of Adult Living Donor Liver Transplantation: A Cumulative Single-Center Cohort Study With 20 Years of Follow-Up.

Living donor liver transplantation (LDLT) is an attractive alternative to deceased donor liver transplantation (DDLT). Although both modalities have similar short-term outcomes, long-term outcomes are not well studied. We compared the 20-year outcomes of 668 adults who received LDLT with1596 DDLTs at the largest liver transplantation (LT) program in Canada. Recipients of LDLT were significantly younger and more often male than DDLT recipients (P < 0.001). Autoimmune diseases were more frequent in LDLT, whereas viral hepatitis and alcohol-related liver disease were more frequent in DDLT. LDLT recipients had lower Model for End-Stage Liver Disease scores (P = 0.008), spent less time on the waiting list (P < 0.001), and were less often inpatients at the time of LT (P < 0.001). In a nonadjusted analysis, 1-year, 10-year, and 20-year patient survival rates were significantly higher in LDLT (93%, 74%, and 56%, respectively) versus DDLT (91%, 67%, and 46%, respectively; log-rank P = 0.02) as were graft survival rates LDLT (91%, 67%, and 50%, respectively) versus (90%, 65%, and 44.3%, respectively, for DDLT; log-rank P = 0.31). After multivariable adjustment, LDLT and DDLT were associated with a similar hazard of patient and graft survival. Our data of 20 years of follow-up of LDLT from a single, large Western center demonstrates excellent long-term outcomes for recipients of LDLT.

Low-dose aspirin confers protection against acute cellular allograft rejection after primary liver transplantation.

This study investigated the effect of low-dose aspirin in primary adult liver transplantation (LT) on acute cellular rejection (ACR) as well as arterial patency rates. The use of low-dose aspirin after LT is practiced by many transplant centers to minimize the risk of hepatic artery thrombosis (HAT), although solid recommendations do not exist. However, aspirin also possesses potent anti-inflammatory properties and might mitigate inflammatory processes after LT, such as rejection. Therefore, we hypothesized that the use of aspirin after LT has a protective effect against ACR. This is an international, multicenter cohort study of primary adult deceased donor LT. The study included 17 high-volume LT centers and covered the 3-year period from 2013 to 2015 to allow a minimum 5-year follow-up. In this cohort of 2365 patients, prophylactic antiplatelet therapy with low-dose aspirin was administered in 1436 recipients (61%). The 1-year rejection-free survival rate was 89% in the aspirin group versus 82% in the no-aspirin group (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.63-0.94; p = 0.01). The 1-year primary arterial patency rates were 99% in the aspirin group and 96% in the no-aspirin group with an HR of 0.23 (95% CI, 0.13-0.40; p < 0.001). Low-dose aspirin was associated with a lower risk of ACR and HAT after LT, especially in the first vulnerable year after transplantation. Therefore, low-dose aspirin use after primary LT should be evaluated to protect the liver graft from ACR and to maintain arterial patency.

Does machine perfusion improve immediate and short-term outcomes by enhancing graft function and recipient recovery after liver transplantation? A systematic review of the literature, meta-analysis and expert panel recommendations.

BACKGROUND: Recent evidence supports the use of machine perfusion technologies (MP) for marginal liver grafts. Their effect on enhanced recovery, however, remains uncertain. OBJECTIVES: To identify areas in which MP might contribute to an ERAS program and to provide expert panel recommendations. DATA SOURCES: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central. METHODS: Systematic review and meta-analysis following PRISMA guidelines and recommendations using the GRADE approach. CRD42021237713 RESULTS: Both hypothermic (HMP) and normothermic (NMP) machine perfusion demonstrated significant benefits in preventing postreperfusion syndrome (PRS) (HMP OR .33, .15-.75 CI; NMP OR .51, .29-.90 CI) and early allograft dysfunction (EAD) (HMP OR .51, .35-.75 CI; NMP OR .66, .45-.97 CI), while shortening LOS (HMP MD -3.9; NMP MD -12.41). Only NMP showed a significant decrease in the length of ICU stay (L-ICU) (MD -7.07, -8.76; -5.38 CI), while only HMP diminishes the likelihood of major complications. Normothermic regional perfusion (NRP) reduces EAD (OR .52, .38-.70 CI) and primary nonfunction (PNF) (OR .51, .27-.98 CI) without effect on L-ICU and LOS. CONCLUSIONS: The use of HMP decreases PRS and EAD, specifically for marginal grafts. This is supported by a shorter LOS and a lower rate of major postoperative complications (QOE; moderate | Recommendation; Strong). NMP reduces the incidence of PRS and EAD with associated shortening in L-ICU for both DBD and DCD grafts (QOE; moderate | Recommendation; High) This technology also shortens the length of hospital stay (QOE; low | Recommendation; Strong). NRP decreases the likelihood of EAD (QOE; moderate) and the risk of PNF (QOE; low) when compared to both DBD and SRR-DCD grafts preserved in SCS. (Recommendation; Strong).

Optimal surgical workup to ensure safe recovery of the donor after living liver donation - A systematic review of the literature and expert panel recommendations.

BACKGROUND: The essential premise of living donor liver transplantation is the assurance that the donors will have a complication-free perioperative course and a prompt recovery. Selection of appropriate donors is the first step to support this premise and is based on tests that constitute the donor workup. The exclusion of liver pathologies and assessment of liver anatomy and volume in the donor candidate are the most important elements in the selection of the appropriate candidate. OBJECTIVE: To determine whether there is evidence to define an optimal donor surgical workup that would improve short-term outcomes of the donor after living liver donation. DATA SOURCES: Ovid Medline, Embase, Scopus, Google Scholar, and Cochrane Central. METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. RESULTS: Although a liver biopsy remains the only method to exactly determine the percentage and type of steatosis and to detect other liver pathologies, its routine use is not supported. Both magnetic resonance imaging (MRI) and computed tomography (CT) appear to be adequate for quantifying liver volume; the preference for one or the other is often based on center expertise. MRI is clearly a better technique to assess biliary anatomy, although aberrant biliary anatomy may not be clearly detected. MRI is also more accurate than CT in determining low grades of steatosis. CT angiography is the imaging test of choice to assess the vascular anatomy. There is no evidence of the need for catheter angiography in the modern evaluation of a living liver donor. CONCLUSIONS: A donor liver biopsy is indicated if abnormalities are present in serological or imaging tests. Both MRI and CT imaging appear to be adequate methodologies. The routine use of catheter angiography is not supported in view of the adequacy of CT angiography in delineating liver vascular anatomy. No imaging modality available to quantify liver volume is superior to another. Biliary anatomy is better defined with MRI, although poor definition can be expected, particularly for abnormal ducts.

Living donor liver paired exchange: A North American first.

Paired organ exchange can be used to circumvent living donor-recipient ABO incompatibilities. Herein, we present the first case of successful liver paired exchange in North America. This 2-way swap required 4 simultaneous operations: 2 living donor hepatectomies and 2 living donor liver transplants. A nondirected anonymous living donor gift initiated this domino exchange, alleviating an ABO incompatibility in the other donor-recipient pair. With careful attention to ethical and logistical issues, paired liver exchange is a feasible option to expand the donor pool for incompatible living liver donor-recipient pairs.

Extinguishing burnout: National analysis of predictors and effects of burnout in abdominal transplant surgery fellows.

Burnout among surgeons has been attributed to increased workload and decreased autonomy. Although prior studies have examined burnout among transplant surgeons, no studies have evaluated burnout in abdominal transplant surgery fellows. The objective of our study was to identify predictors of burnout and understand its impact on personal and patient care during fellowship. A survey was sent to all abdominal transplant surgery fellows in an American Society of Transplant Surgeons-accredited fellowship. The response rate was 59.2% (n = 77) and 22.7% (n = 17) of fellows met criteria for burnout. Fellows with lower grit scores were more likely to exhibit burnout compared with fellows with higher scores (3.6 vs 4.0, P = .026). Those with burnout were more likely to work >100 hours per week (58.8% vs 27.6%, P = .023), have severe work-related stress (58.8% vs 22.4%, P = .010), consider quitting fellowship (94.1% vs 20.7%, P < .001), or make a medical error (35.3% vs 5.2%, P = .003). This national analysis of abdominal transplant fellows found that burnout rates are relatively low, but few fellows engage in self-care. Personal and program-related factors attribute to burnout and it has unacceptable effects on patient care. Transplant societies and fellowship programs should develop interventions to give fellows tools to prevent and combat burnout.

Ex vivo machine perfusion: current applications and future directions in liver transplantation.

BACKGROUND: Liver transplantation is the only curative treatment option for end-stage liver disease; however, its use remains limited due to a shortage of suitable organs. In recent years, ex vivo liver machine perfusion has been introduced to liver transplantation, as a means to expand the donor organ pool. PURPOSE: To present a systematic review of prospective clinical studies on ex vivo liver machine perfusion, in order to assess current applications and highlight future directions. METHODS: A systematic literature search of both PubMed and ISI web of science databases as well as the ClinicalTrials.gov registry was performed. RESULTS: Twenty-one articles on prospective clinical trials on ex vivo liver machine perfusion were identified. Out of these, eight reported on hypothermic, eleven on normothermic, and two on sequential perfusion. These trials have demonstrated the safety and feasibility of ex vivo liver machine perfusion in both standard and expanded criteria donors. Currently, there are twelve studies enrolled in the clinicaltrials.gov  registry, and these focus on use of ex vivo perfusion in extended criteria donors and declined organs. CONCLUSION: Ex vivo liver machine perfusion seems to be a suitable strategy to expand the donor pool for liver transplantation and holds promise as a platform for reconditioning diseased organs.

Lymphoceles: impact on kidney transplant recipients, graft, and healthcare system.

INTRODUCTION: Following kidney transplantation, lymphoceles can impact patient and graft outcomes, while resulting in significant hospital resource utilization. We aimed to characterize the incidence, risk factors, outcomes, and clinical management of lymphoceles among kidney transplant recipients and review impact on health system utilization at a high-volume center. MATERIALS AND METHODS: We conducted a single-center, observational cohort study on adults transplanted between January 1, 2005 and December 31, 2017. Incidence, risk factors, and clinical outcomes were assessed using the Kaplan-Meier product-limit method, multivariable logistic regression model, and Cox proportional hazards model, respectively. RESULTS: Lymphoceles developed in 72 of 1881 patients (3.8%). Multivariate analysis demonstrated that a longer time on dialysis before transplant [HR 1.09 (95% CI: 1.02, 1.17)], laparoscopic donor nephrectomy [HR 2.31 (95% CI: 1.04, 5.12)], and depleting induction therapy [HR 0.39 (95% CI: 0.18, 0.87)] were significant risk factors for lymphocele development. Lymphoceles independently increased the likelihood of hospital readmission [HR 3.96 (95% CI: 2.99, 5.25)] but had no significant effect on the likelihood of graft failure or death with graft function. Of 72 cases, 44 received a radiological or surgical intervention. Fifteen of 44 lymphoceles required further intervention due to re-accumulation or complications. CONCLUSION: Patients with longer dialysis times, kidneys from laparoscopic donor nephrectomy, and depleting induction therapy were associated with an increased risk for developing symptomatic lymphoceles. Our center's treatment for symptomatic lymphoceles did not result in significant graft dysfunction, but significantly higher healthcare resource utilization was noted.