Outcomes of right-lobe and left-lobe living-donor liver transplantations using small-for-size grafts

Risk factors for biliary strictures and leaks after living-donor liver transplantation: a systematic review and meta-analysis

BACKGROUND

Liver transplantation is the only curative treatment of end-stage liver disease. Unfortunately, a significant number of patients on the organ waitlist die waiting for an organ. Living-donor liver transplantation (LDLT) is an approach that has been used to expand organ availability. Although LDLT has excellent outcomes, biliary complications remain a significant drawback. This meta-analysis aimed to precisely assess the predictors of biliary stricture and leak after LDLT.

METHODS

PubMed, Embase, and Web of Science databases were searched from inception to January 2024. Only studies that used a multivariate model to assess risk factors for post-LDLT biliary stricture or leak in adult participants were included. Studies reporting unadjusted risk factors were excluded. Pooled adjusted odds ratios (ORs) and pooled hazard ratios (HRs) with 95% CIs for risk factors reported in ≥2 studies were obtained within a random-effects model.

RESULTS

Overall, 22 studies with 9442 patients who underwent LDLT were included. The post-LDLT biliary stricture rate was 22%, whereas the post-LDLT biliary leak rate was 14%. In addition, 13 unique risk factors were analyzed. Postoperative bile leak (OR, 4.10 [95% CI, 2.88-5.83]; HR, 3.88 [95% CI, 2.15-6.99]) was the most significant predictor of biliary stricture after LDLT. Other significant predictors of biliary stricture after LDLT were right lobe graft (OR, 2.56; 95% CI, 1.23-5.32), multiple ducts for anastomosis (OR, 1.62; 95% CI, 1.08-2.43), ductoplasty (OR, 2.07; 95% CI, 1.36-3.13), ABO incompatibility (OR, 1.45; 95% CI, 1.16-1.81), and acute cellular rejection (OR, 4.10; 95% CI, 2.88-5.83). Donor bile duct size (HR, 0.82; 95% CI, 0.74-0.91; P = .001, I2 = 0%) was found to be significantly associated with reduced risk of post-LDLT biliary stricture. Donor age, recipient age, recipient male sex, and duct-to-duct anastomosis were not associated with an increased risk of post-LDLT biliary strictures. Multiple ducts for anastomosis (OR, 1.86; 95% CI, 1.43-2.43) was a significant predictor of post-LDLT biliary leak. Recipient age, warm ischemia time, and duct-to-duct anastomosis were not associated with an increased risk of post-LDLT biliary leak.

CONCLUSION

In this meta-analysis, 7 unique risk factors were shown to be predictive of post-LDLT biliary stricture, one of which was associated with both post-LDLT biliary stricture and leak. Donor bile duct size was found to be protective against post-LDLT biliary strictures. Identifying reliable predictors is crucial for recognizing high-risk patients. This approach can facilitate the implementation of preventive measures, surveillance protocols, and targeted interventions to reduce the incidence of biliary strictures after LDLT.

Advocating for a "shift-to-left" in transplant oncology: left grafts, RAPID and dual graft

The extension of liver transplantation to new oncologic indications might exacerbate the shortage of grafts. Living donor liver transplantation (LDLT) may emerge as a viable resource, although its diffusion in the Western world is still very limited. Several groups have advocated for minimizing the impact on donors by reducing the extent of donor hepatectomy, i.e., shifting from right-lobe to left-lobe or left-lateral segment donation ("shift-to-left"). This is particularly relevant when dealing with non-established indications and could make it more acceptable both for potential donors and for the recipients. Left grafts can be transplanted straightforward, despite a higher risk of small-for-size syndrome, or they can be used in the setting of dual-graft LDLT or RAPID procedures, despite technical complexity. This review will expose the most relevant features of each technique, highlighting their strengths and pitfalls and focusing on outcomes. This wide set of tools should be available at high-volume transplant centers, to propose the best technique to adapt to donor-recipient matching.

Increasing practice and acceptable outcomes of high-MELD living donor liver transplantation in the USA

Recent deceased-donor allocation changes in the United States may have increased high-Model for End-Stage Liver Disease (MELD) living donor liver transplantation (LDLT); however, outcomes in these patients remain poorly defined. We aimed to examine the impact of the MELD score on LDLT outcomes. Using UNOS data (January 1, 2010-December 31, 2021), LDLT recipients were identified and stratified into low-MELD (<15), intermediate-MELD (15-24), and high-MELD (≥25) groups. We compared outcomes between MELD-stratified LDLT groups and between MELD-stratified LDLT and donation after brain death liver transplantation recipients. We used Kaplan-Meier analysis to compare graft survival rates and multivariable Cox proportional hazards modeling to identify factors associated with graft outcomes. Of 3558 LDLTs, 1605 (45.1%) were low-MELD, 1616 (45.4%) intermediate-MELD, and 337 (9.5%) high-MELD. Over the study period, the annual number of LDLTs increased from 282 to 569, and the proportion of high-MELD LDLTs increased from 3.9% to 7.7%. Graft survival was significantly higher in low-MELD versus high-MELD LDLT recipients (adjusted HR = 1.36, 95% CI: 1.03-1.79); however, 5-year survival exceeded 70.0% in both groups. We observed no significant difference in graft survival between high-MELD LDLT and high-MELD donation after brain death liver transplantation recipients (adjusted HR: 1.25, 95% CI:0.99-1.58), with a 5-year survival of 71.5% and 77.3%, respectively. Low LDLT center volume (<3 LDLTs/year) and recipient life support requirement were both associated with inferior graft outcomes among high-MELD LDLT recipients. While higher MELD scores confer graft failure risk in LDLT, high-MELD LDLT outcomes are acceptable with similar outcomes to MELD-stratified donation after brain death liver transplantation recipients. Future practice guidance should consider the expansion of LDLT recommendations to high-MELD recipients in centers with expertise to help reduce donor shortage.

A Single-Center's Early Surgical Outcomes of Living Donor Liver Transplantation

BACKGROUND

Living donor liver transplantation (LDLT) has become an increasingly common surgical option because the number of cadaveric donors is insufficient to fulfill the organ needs of patients facing end-stage cirrhosis. Many centers are investigating different surgical techniques to achieve lower complication rates. We aimed to examine our complication rates in light of demographic data, graft data, and perioperative findings as a single-center experience.

METHODS

The study included one hundred and three patients who underwent LDLT for end-stage liver cirrhosis. Demographic data; sex; age; blood group; Model for End-Stage Liver Disease score; Child score; etiology; liver side; graft-to-recipient weight ratio; hepatic artery, portal vein, and bile anastomosis type rates; anhepatic phase; cold ischemia time; operation time; and blood product transfusion rates were analyzed. Biliary complications in patients with single or multiple biliary anastomoses, right or left liver transplants, and with or without hepatic artery thrombosis were analyzed statistically.

RESULTS

There was no significant difference in biliary complications between patients who underwent single or multiple bile anastomosis (P = .231) or patients receiving right lobe and left lobe transplants (P = .315). Although there was no statistically significant difference in the rate of portal vein thrombosis between the regular and reconstructed portal vein anastomosis groups (P = .693), the postoperative portal vein thrombosis rate was statistically higher in patients with left lobe transplants (P = .044).

CONCLUSIONS

Vascular and biliary complication rates can be reduced with increasing experience.

Right Lobe Versus Left Lobe Living Donor Liver Transplantation: A Systematic Review and Meta-analysis of Donor and Recipient Outcomes

BACKGROUND

Living donor liver transplantation (LDLT) is an established treatment for advanced liver disease. Whether right lobe (RL) or left lobe (LL) LDLT provides the best outcomes for donors and recipients remains contentious.

METHODS

MedLine, Embase, PubMed, and Cochrane Central were searched to identify studies comparing RL- and LL-LDLT and reporting donor and/or recipient outcomes. Effect sizes were pooled using random-effect meta-analysis. Meta-regressions were used to explore heterogeneity.

RESULTS

Sixty-seven studies were included. RL donors were more likely to experience major complications (relative risk [RR] = 1.63; 95% confidence interval [CI] = 1.30-2.05; I2 = 19%) than LL donors; however, no difference was observed in the risk of any biliary complication (RR = 1.41; 95% CI = 0.91-2.20; I2 = 59%), bile leaks (RR = 1.56; 95% CI = 0.97-2.51; I2 = 52%), biliary strictures (RR = 0.99; 95% CI = 0.43-1.88; I2 = 27%), or postoperative death (RR = 0.51; 95% CI = 0.25-1.05; I2 = 0%). Among recipients, the incidence of major complications (RR = 0.85; 95% CI = 0.68-1.06; I2 = 21%), biliary complications (RR = 1.10; 95% CI = 0.91-1.33; I2 = 8%), and vascular complications (RR = 0.79; 95% CI = 0.44-1.43; I2 = 0%) was similar. Although the rate of small for size syndrome (RR = 0.47; 95% CI = 0.30-0.74; I2 = 0%) and postoperative deaths (RR = 0.62; 95% CI = 0.44-0.87; I2 = 0%) was lower among RL-LDLT recipients, no differences were observed in long-term graft (hazard ratio = 0.87; 95% CI = 0.55-1.38; I2 = 74%) and overall survival (hazard ratio = 0.86; 95% CI = 0.60-1.22; I2 = 44%).

CONCLUSIONS

LL donors experience fewer complications than RL donors, and LL-LDLT recipients had similar outcomes to RL-LDLT recipients. These findings suggest that LL-LDLT offers the best outcomes for living donors and similar outcomes for recipients when measures are taken to prevent small for size syndrome.

Paired Exchange Living Donor Liver Transplantation: A Nine-year Experience From North India

BACKGROUND

Paired exchange liver transplantation is an evolving strategy to overcome ABO blood group incompatibility and other barriers such as inadequate graft-to-recipient weight ratio and low remnant liver volume in donors. However, for the transplant team to carry 4 major operations simultaneously is a Herculean effort. We analyzed our experience with liver paired exchange (LPE) program over the past 9 y.

METHODS

This prospective study included 34 of 2340 (1.45%) living donor liver transplantations performed between May 2012 and April 2021. The reason for LPE was ABO incompatibility in all (n = 34) patients included in the study. After donor reassignment through 2-by-2 paired exchange with directed donors, the ABO matching status changed from A to A (n = 17) and B to B (n = 17), which made all matches ABO-identical. Recipients (R) and donors (D) of each swap pair were prospectively divided into R1/D1 and R2/D2 groups for comparative and survival analyses.

RESULTS

The recipients (n = 34) had a median age of 45.5 y (11-59 y), and 31 were men. LPEs were performed in 4 operating rooms running simultaneously by 2 independent surgical teams. Donor survival was 100%. Baseline clinical and perioperative parameters, postoperative complications, median intensive care unit/hospital stay, and early deaths were comparable (P > 0.1) between the R1 and R2 groups. The median follow-up period was 27 mo (1-108 mo). The 30-d and 1-y survivals were 88.2% (n = 30) and 85.3% (n = 29), respectively.

CONCLUSIONS

Our experience suggests that with careful attention to ethical and logistical issues, the LPE program can expand the living donor liver pool and facilitate a greater number of living donor liver transplantations.

Long-term Outcomes of Stent Placement Inside the Bile Duct for Biliary Strictures After Living Donor Liver Transplantation

In living donor liver transplantation (LDLT), anastomotic biliary stricture is a serious and refractory complication. In this study, we reviewed the transition of post-LDLT anastomotic biliary strictures and evaluated long-term outcomes of stent placement inside the bile duct, which is referred to as an "inside-stent." Of 805 consecutive adult LDLT recipients in our institution (2000-2018), we reviewed 639 patients with duct-to-duct biliary reconstruction and analyzed chronological changes of post-LDLT biliary strictures. Moreover, we focused on the year 2006 when various surgical modifications were introduced and compared the details of post-LDLT biliary strictures before and after 2006, especially focusing on the long-term outcome of inside-stent placement. The proportion of left lobe grafts had increased from 1.8% before 2005 to 39.3% after 2006 (P < 0.001) to maximize the living donor safety. Overall, post-LDLT anastomotic biliary strictures occurred in 21.3% of the patients with a median follow-up period of 106.1 months, which was decreased from 32.6% before 2005 to 12.8% after 2006 (P < 0.001). Anastomotic biliary strictures were less frequent in patients with left lobe grafts than with right lobe grafts (9.4% versus 25.4%; P < 0.001). The overall technical success rate of inside-stent placement was 82.4%, with an improvement from 75.3% before 2005 up to 95.7% after 2006 (P < 0.01). Furthermore, the stricture resolution rate remained high at approximately 90% throughout the observation period. Increased use of left lobe grafts with several surgical modifications significantly reduced post-LDLT anastomotic biliary strictures, leading to favorable long-term outcomes of inside-stent placements for this condition.

Donor Morbidity Is Equivalent Between Right and Left Hepatectomy for Living Liver Donation: A Meta-Analysis

Maximizing liver graft volume benefits the living donor liver recipient. Whether maximizing graft volume negatively impacts living donor recovery and outcomes remains controversial. Patient randomization between right and left hepatectomy has not been possible due to anatomic constraints; however, a number of published, nonrandomized observational studies summarize donor outcomes between 2 anatomic living donor hepatectomies. This meta-analysis compares donor-specific outcomes after right versus left living donor hepatectomy. Systematic searches were performed via PubMed, Cochrane, ResearchGate, and Google Scholar databases to identify relevant studies between January 2005 and November 2019. The primary outcomes compared overall morbidity and incidence of severe complications (Clavien-Dindo >III) between right and left hepatectomy in donors after liver donation. Random effects meta-analysis was performed to derive summary risk estimates of outcomes. A total of 33 studies (3 prospective and 30 retrospective cohort) were used to identify 7649 pooled patients (5993 right hepatectomy and 1027 left hepatectomy). Proportion of donors who developed postoperative complications did not significantly differ after right hepatectomy (0.33; 95% confidence interval [CI], 0.27-0.40) and left hepatectomy (0.23; 95% CI, 0.17-0.29; P = 0.19). The overall risk ratio (RR) did not differ between right and left hepatectomy (RR, 1.16; 95% CI, 0.83-1.63; P = 0.36). The relative risk for a donor to develop severe complications showed no differences by hepatectomy side (Incidence rate ratio, 0.97; 95% CI, 0.67-1.40; P = 0.86). There is no evidence that the overall morbidity differs between right and left lobe donors. Publication bias reflects institutional and surgeon variation. A prospective, standardized, multi-institutional study would help quantify the burden of donor complications after liver donation.

Is 0.6% Reasonable as the Minimum Requirement of the Graft-to-recipient Weight Ratio Regardless of Lobe Selection in Adult Living-donor Liver Transplantation?

BACKGROUND

Several studies reported favorable outcomes of small-for-size grafts with graft-to-recipient weight ratio (GRWR) <0.8% in living-donor liver transplantation (LDLT). However, their indications should be carefully determined because they must have been indicated for low-risk cases over larger grafts with 0.8% ≤ GRWR. Furthermore, evidence for minimum requirements of GRWR remains inconclusive. We investigated the safety of small-for-size grafts against larger grafts by adjusting for confounding risk factors, and minimum requirement of graft volume in adult LDLT.

METHODS

We enrolled 417 cases of primary adult-to-adult LDLT in our center between 2006 and 2019. The outcomes of small grafts (0.6% ≤ GRWR < 0.8%, n = 113) and large grafts (0.8% ≤ GRWR, n = 289) were mainly compared using a multivariate analysis and Kaplan-Meier estimates.

RESULTS

The multivariate analysis showed that small grafts were not a significant risk factor for overall graft survival (GS). In the Kaplan-Meier analysis, small grafts did not significantly affect overall GS regardless of lobe selection (versus large grafts). However, GRWR < 0.6% was associated with poor overall GS. Although there were no significant differences between the 2 groups, unadjusted Kaplan-Meier curves of small grafts were inferior to those of large grafts in subcohorts with ABO incompatibility, and donor age ≥50 years.

CONCLUSIONS

Similar outcomes were observed for small and large graft use regardless of lobe selection. 0.6% in GRWR was reasonable as the minimum requirement of graft volume in LDLT. However, small grafts should be indicated carefully for high-risk cases.

Dextroplantation of Left Liver Graft in Infants

The position of the left side liver graft is important, and it could lead to complications of the hepatic vein (HV) and portal vein (PV), especially in a small child using a variant left lateral section (vLLS) graft. The purpose of this study was to evaluate the outcome of a novel technique for the implantation of a vLLS graft to the right side (dextroplantation) in infants. For 3 years, 10 consecutive infants underwent dextroplantation using a vLLS graft (group D). The graft was implanted to the right side of the recipient after 90° counterclockwise rotation; the left HV graft was anastomosed to inferior vena cava using the extended right and middle HV stump, and PV was reconstructed using oblique anastomosis without angulation. Surgical outcomes were compared with the historical control group (n = 17, group C) who underwent conventional liver transplantation using a vLLS during infancy. Group D recipients were smaller than group C (body weight <6 kg: 50.0% versus 11.8%; P = 0.03). The rate of graft-to-recipient weight ratio >4% was higher in group D (60.0%) than C (11.8%; P = 0.01). Surgical drains were removed earlier in group D than in group C (15 versus 18 postoperative days [PODs]; P = 0.048). Each group had 1 PV complication (10.0% versus 5.9%); no HV complication occurred in group D, but 3 HV complications (17.6%) occurred in group C (P > 0.05). Hospital stay was shorter in group D than in group C (20 versus 31 PODs; P = 0.02). Dextroplantation of a vLLS graft, even a large-for-size one, was successful in small infants without compromising venous outcomes, compared with conventional vLLS transplantation. We could remove the surgical drains earlier and reduce hospital stays in cases of dextroplantation.

Post-operative imaging anatomy in liver transplantation

The article describes and illustrates the surgical techniques and the post-operative imaging anatomy in liver transplantation. Special attention is paid to the variant vascular and biliary anatomy that are important for surgical planning. Considering the ever-growing number of liver transplants performed and the key role that imaging plays in the pre-operative planning and post-operative assessment, it is important for the radiologist to be familiar with the surgical techniques and the normal post-operative appearance in these patients.

Organ Restoration With Normothermic Machine Perfusion and Immune Reaction

Liver transplantation is the only recognized effective treatment for end-stage liver disease. However, organ shortages have become the main challenge for patients and physicians within the transplant community. Waiting list mortality remains an issue with around 10% of patients dying whilst waiting for an available organ. The post-transplantation period is also associated with an adverse complication rate for these specific cohorts of high-risk patients, particularly regarding patient and graft survival. Ischaemia reperfusion injury (IRI) has been highlighted as the mechanism of injury that increases parenchymal damage, which eventually lead to significant graft dysfunction and other poor outcome indicators. The consequences of IRI in clinical practice such as reperfusion syndrome, primary non-function of graft, allograft dysfunction, ischaemic biliary damage and early biliary complications can be life-threatening. IRI dictates the development of a significant inflammatory response that drives the pathway to eventual cell death. The main mechanisms of IRI are mitochondrial damage due to low oxygen tension within the hepatic micro-environment and severe adenosine triphosphate (ATP) depletion during the ischaemic period. After the restoration of normal blood flow, this damage is further enhanced by reoxygenation as the mitochondria respond to reperfusion by releasing reactive oxygen species (ROS), which in turn activate Kupffer cells within the hepatic micro-environment, leading to a pro-inflammatory response and eventual parenchymal cell apoptosis and associated tissue degradation. Machine perfusion (MP) is one emergent strategy considered to be one of the most important advances in organ preservation, restoration and transplantation. Indeed, MP has the potential to rescue frequently discarded organs and has been shown to limit the extent of IRI, leading to suppression of the deleterious pro-inflammatory response. This immunomodulation reduces the prevalence of allograft rejection, the use of immunosuppression therapy and minimizes post-transplant complications. This review aims to update the current knowledge of MP with a focus on normothermic machine liver perfusion (NMLP) and its potential role in immune response pathways.

Risk of biliary tract disease in living liver donors: A population-based cohort study

BACKGROUND & AIMS

Whether living liver donors have a higher risk of biliary tract disease compared with non-donors remains unknown.

METHODS

Data were collected from the Taiwan Longitudinal Health Insurance Database for the 2003-2011 period. The study cohort comprised 1,446 patients aged ≥ 18 years who had served as living liver donors. The primary outcome was the incidence of biliary tract disease. Cox proportional hazards modeling was used to determine the hazard ratios.

RESULTS

The incidence density rate of biliary tract disease was 13.9-fold higher in the liver donor (LD) cohort than in the non-LD cohort (10.2 vs. 0.71 per 1,000 person-years), with an adjusted hazard ratio (HR) of 14.2 (95% confidence interval [CI] = 7.73-26.1). Stratified by comorbidity, the relative risk of biliary tract disease was higher in the LD cohort than in the non-LD cohort for both patients with or without comorbidity. The incidence density rate of biliary tract disease was significantly higher in the first 3 years (13.5 per 1,000 person-years in the LD cohort). The highest adjusted HR of biliary tract disease for LD patients compared with the non-LD cohort was 22.4 (95% CI = 10.8-46.1) in the follow-up ≤ 3 years.

CONCLUSION

Living liver donors had a higher risk of biliary tract disease compared with non-donors.

Liver Transplantation for Hepatitis B Virus-related Hepatocellular Carcinoma in Hong Kong

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer-related deaths worldwide. Curative resection is frequently limited in Hong Kong by hepatitis B virus-related cirrhosis, and liver transplantation is the treatment of choice. Liver transplantation has been shown to produce superior oncological benefits, when compared to hepatectomy for HCC. New developments in the context of patient selection criteria, modification of organ allocation, bridging therapy, salvage liver transplantation and pharmaceutical breakthrough have improved the survival of HCC patients. In this article, we will share our experience in transplanting hepatitis B virus-related HCC patients in Hong Kong and discuss the recent progress in several areas of liver transplantation.

Feasibility of using marginal liver grafts in living donor liver transplantation

Liver transplantation (LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally, despite the decrease in the prevalence of hepatitis B virus (HBV) over the past two decades, the absolute number of HBsAg-positive people has increased, leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently, a large demand exists for LT. While the wait time for patients on the donor list is, to some degree, shorter due to the development of living donor liver transplantation (LDLT), there is still a shortage of liver grafts. Furthermore, recipients often suffer from emergent conditions, such as liver dysfunction or even hepatic encephalopathy, which can lead to a limited choice in grafts. To expand the pool of available liver grafts, one option is the use of organs that were previously considered "unusable" by many, which are often labeled "marginal" organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however, there is still a lack of discussion on this topic, especially regarding the feasibility of using marginal grafts in LDLT. Therefore, the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.