Anatomical Variations of Left Hepatic Vein and Outflow Reconstruction Techniques in Paediatric Living Donor Liver Transplantation

Anatomical variations of left hepatic vein (LHV) are observed in nearly a third of left lateral segment (LLS) donors in living donor liver transplantation (LDLT). There is paucity of studies and no structured algorithm for customised outflow reconstruction in LLS grafts with variant anatomy. Analysis of a prospectively collected database of 296 LLS paediatric LDLT was done to identify different venous drainage patterns of segments 2 (V2) and 3 (V3). LHV anatomy was classified into three types: type 1(n=270, 91.2%): V2 and V3 joined to form a common trunk which drains into middle hepatic vein (MHV)/inferior vena cava (IVC), subtype 1a length of trunk ≥ 9mm and subtype 1b length of trunk < 9mm; type 2(n=6, 2%): V2 and V3 drain independently into IVC; type 3(n=20, 6.8%): V2 and V3 drain into IVC and MHV respectively. Analysis of post-operative outcomes between LLS grafts with single and reconstructed multiple outflows showed no difference in the occurrence of hepatic vein thrombosis/stenosis, major morbidity (p 0.91) and 5 year survival (log rank p 0.562). This classification is a simple yet effective tool for pre-operative donor assessment and we propose a schema for customised reconstruction of LLS grafts, with excellent and consistently reproducible outcomes.

Cardiovascular mechanism of donor brain death and heart recipient survival

BACKGROUND

Heart donation after donor brain death from cardiac arrest despite successful resuscitation may be associated with worse recipient outcomes due to potential graft ischemia or underlying rhythmic/structural defects. However, selected grafts from such donors often have normal cardiac function and anatomy. We investigated whether a cardiovascular mechanism of donor brain death (CV-DBD) was associated with worse recipient outcomes.

METHODS

We queried the United Network for Organ Sharing (UNOS) database for first-time, single-organ, adult (age 18+) heart transplant recipients and their associated donors between January 2005 and March 2021. Recipients were stratified by donor status (CV-DBD vs. non-CV-DBD). We performed multivariable Cox proportional hazards modeling to ascertain whether receiving a CV-DBD graft was independently associated with mortality.

RESULTS

Of 35,833 included recipients, 2,702 (7.5%) received CV-DBD grafts. The associated donors were significantly more likely to be female, older, and have a history of diabetes, hypertension, and substance use (all p < .001). On unadjusted Kaplan-Meier analysis, CV-DBD recipients had a significantly reduced median survival than non-CV-DBD recipients (12.0 vs. 13.1 years, log-rank p = .04). However, after adjusting for donor/recipient age, recipient comorbidities, annualized center volume, and transplantation era, CV-DBD organ status was not associated with recipient mortality (hazard ratio: 1.05, 95% confidence interval: 0.96-1.13, p = .28).

CONCLUSION

In this analysis of over 35,000 heart transplants, CV-DBD status was not associated with adjusted recipient survival. Donor brain death due to cardiac arrest should not be an absolute contraindication to heart donation, although graft function should be carefully assessed before transplantation.

Comparing outcomes in right versus left kidney transplantation: A systematic review and meta-analysis

INTRODUCTION

Transplantation of right kidneys can pose technical challenges due to the short right renal vein. Whether this results in inferior outcomes remains controversial.

METHOD

Healthcare Database Advanced Search (HDAS) was used to identify relevant studies. Two authors independently reviewed each study. Statistical analyses were performed using random effects models and results expressed as HR or relative risk (RR) with 95% confidence intervals. Subgroup analyses were performed in kidneys from deceased donors (DD) and living donors (LD).

RESULTS

A total of 35 studies (257,429 participants) were identified. Both deceased and living donor right kidneys were at increased risk of delayed graft function (DGF; RR = 1.12[1.06-1.18] and RR = 1.33[1.21-1.46] respectively; both p < .0001). In absolute terms, for each 100 kidney pairs of DD kidneys transplanted there are 2.72 (1.67-3.78, p < .00001) excess episodes of DGF in right kidneys. Graft thromboses and graft loss due to technical failure was also significantly more likely in right kidneys, in both DD and LD settings. There was no evidence that laterality alters long term graft survival in LD or DD.

CONCLUSION

Right kidneys have inferior early outcomes, with higher rates of DGF, technical failure and graft thrombosis. However, these differences are small in absolute terms, and long-term graft survival is equivalent.

Reassessing Recipient Mortality Under the New Heart Allocation System: An Updated UNOS Registry Analysis

BACKGROUND

An early report of recipient heart transplantation outcomes under the new U.S. heart allocation system introduced in late 2018 found a lower post-transplant survival rate compared with that of the prior system.

OBJECTIVES

The aim of this study was to examine recipient survival under the new system by using an updated dataset.

METHODS

The 2015 to 2019 United Network for Organ Sharing registry was queried for adult heart transplant recipients, stratified according to whether the subjects were listed and underwent transplant before or after October 18, 2018, when the new allocation system was implemented. The association between allocation system and recipient mortality was analyzed by using the Kaplan-Meier method and multivariable Cox proportional hazards regression.

RESULTS

A total of 7,119 recipients met inclusion criteria: 6,004 (84%) and 1,115 (16%) listed and undergoing transplant in the old and new allocation systems, respectively. This registry update included 576 new-system recipients, more than double the amount previously analyzed. Recipients from the new system were more likely to be bridged to transplant with temporary mechanical circulatory support devices instead of durable left ventricular assist devices and had longer graft ischemic times. After adjustment, the new system was not associated with poorer survival on Kaplan-Meier survival analysis (log-rank test; p = 0.075) or multivariable Cox proportional hazards modeling (adjusted hazard ratio: 1.18; 95% confidence interval: 0.90 to 1.55).

CONCLUSIONS

The short-term survival of recipients listed and receiving a transplant under the old and new allocation systems seems to be comparable. The modification to the allocation system has resulted in several changes to the clinical profiles of patients undergoing transplants that must be closely monitored in the coming years.

Effects of donor cause of death, ischemia time, inotrope exposure, troponin values, cardiopulmonary resuscitation, electrocardiographic and echocardiographic data on recipient outcomes: A review of the literature

BACKGROUND

Heart transplantation has become standard of care for pediatric patients with either end-stage heart failure or inoperable congenital heart defects. Despite increasing surgical complexity and overall volume, however, annual transplant rates remain largely unchanged. Data demonstrating pediatric donor heart refusal rates of 50% suggest optimizing donor utilization is critical. This review evaluated the impact of donor characteristics surrounding the time of death on pediatric heart transplant recipient outcomes.

METHODS

An extensive literature review was performed to identify articles focused on donor characteristics surrounding the time of death and their impact on pediatric heart transplant recipient outcomes.

RESULTS

Potential pediatric heart transplant recipient institutions commonly receive data from seven different donor death-related categories with which to determine organ acceptance: cause of death, need for CPR, serum troponin, inotrope exposure, projected donor ischemia time, electrocardiographic, and echocardiographic results. Although DITs up to 8 hours have been reported with comparable recipient outcomes, most data support minimizing this period to <4 hours. CVA as a cause of death may be associated with decreased recipient survival but is rare in the pediatric population. Otherwise, however, in the setting of an acceptable donor heart with a normal echocardiogram, none of the other data categories surrounding donor death negatively impact pediatric heart transplant recipient survival.

CONCLUSIONS

Echocardiographic evaluation is the most important donor clinical information following declaration of brain death provided to potential recipient institutions. Considering its relative importance, every effort should be made to allow direct image visualization.

The impact of intraoperative fluid management during laparoscopic donor nephrectomy on donor and recipient outcomes

BACKGROUND

Intraoperative fluid management during laparoscopic donor nephrectomy (LDN) may have a significant effect on donor and recipient outcomes. We sought to quantify variability in fluid management and investigate its impact on donor and recipient outcomes.

METHODS

A retrospective review of patients who underwent LDN from July 2011 to January 2016 with paired kidney recipients at a single center was performed. Patients were divided into tertiles of intraoperative fluid management (standard, high, and aggressive). Donor and recipient demographics, intraoperative data, and postoperative outcomes were analyzed.

RESULTS

Overall, 413 paired kidney donors and recipients were identified. Intraoperative fluid management (mL/h) was highly variable with no correlation to donor weight (kg) (R = 0.017). The aggressive fluid management group had significantly lower recipient creatinine levels on postoperative day 1. However, no significant differences were noted in creatinine levels out to 6 months between groups. No significant differences were noted in recipient postoperative complications, graft loss, and death. There was a significant increase (P < 0.01) in the number of total donor complications in the aggressive fluid management group.

CONCLUSIONS

Aggressive fluid management during LDN does not improve recipient outcomes and may worsen donor outcomes compared to standard fluid management.

Associations between Deceased-Donor Urine MCP-1 and Kidney Transplant Outcomes

Introduction

Existing methods to predict recipient allograft function during deceased-donor kidney procurement are imprecise. Understanding the potential renal reparative role for monocyte chemoattractant protein-1 (MCP-1), a cytokine involved in macrophage recruitment after injury, might help to predict allograft outcomes.

Methods

We conducted a substudy of the multicenter prospective Deceased Donor Study cohort that evaluated deceased kidney donors from 5 organ procurement organizations from May 2010 to December 2013. We measured urine MCP-1 (uMCP-1) concentrations from donor samples collected at nephrectomy to determine associations with donor acute kidney injury (AKI), recipient delayed graft function (DGF), 6-month estimated glomerular filtration rate (eGFR), and graft failure. We also assessed perfusate MCP-1 concentrations from pumped kidneys for associations with DGF and 6-month eGFR.

Results

AKI occurred in 111 donors (9%). The median (interquartile range) uMCP-1 concentration was higher in donors with AKI compared with donors without AKI (1.35 [0.41–3.93] ng/ml vs. 0.32 [0.11–0.80] ng/ml, P < 0.001). DGF occurred in 756 recipients (31%), but uMCP-1 was not independently associated with DGF. Higher donor uMCP-1 concentrations were independently associated with a higher 6-month eGFR in those without DGF (0.77 [0.10–1.45] ml/min per 1.73 m² per doubling of uMCP1). However, there were no independent associations between uMCP-1 and graft failure over a median follow-up of ∼2 years. Lastly, perfusate MCP-1 concentrations significantly increased during pump perfusion but were not associated with DGF or 6-month eGFR.

Discussion

Donor uMCP-1 concentrations were modestly associated with higher recipient 6-month eGFR in those without DGF. However, the results suggest that donor uMCP-1 has minimal clinical utility given no associations with graft failure.