Living donor liver transplantation. Curr Opin Organ Transplant. 2019;24:131-137. [PMID: 30694993 DOI: 10.1097/mot.0000000000000610]

The aim of donor safety: surgical approaches and current results

Living liver donation (LLD) has been suggested as a potential solution to reduce the waitlist mortality for liver transplantation (LT) recipients by facilitating living donor liver transplantation (LDLT). Ensuring both donor and recipient safety is a critical aspect of LDLT. An accurate understanding of the complexity and extend of safety outcomes of the donor is imperative to maintain the high-quality standard this medical program requires. This review seeks to outline safety outcome parameters of interest for donors. Early postoperative mortality is very low with no significant differences comparing left lobe to right lobe LLD. Complications most commonly are biliary (leakage or strictures), bleeding, respiratory or pulmonary, gastrointestinal or infectious. Return to full-time work and quality of life are essential parameters in the mid and long term. As evidence continues to accumulate, outcomes may evolve with the expansion of minimal invasive surgery practice and currently laparoscopic approach is recommended in large experienced centers. By offering safer operations that require fewer incisions or liver resections, living liver donations can be further encouraged, and the perception of the procedure can be improved. Rational consideration of the safety of the donor and in-depth discussion and evaluation with the patient is of utmost importance.

The role of living donor liver transplantation in treating intrahepatic cholangiocarcinoma

Introduction

Intrahepatic cholangiocarcinoma (iCC) is the liver's second most common neoplasm. Until now, surgery is the only curative option, but only 35% of the cases are considered resectable at the diagnosis, with a post-resection survival of around 30%. Advancements in surgical techniques and perioperative care related to liver transplantation (LT) have facilitated the expansion of indications for hepatic neoplasms.

Method

This study is a comprehensive review of the global experience in living donor LT (LDLT) for treating iCC and describes our first case of LDLT for an unresectable iCC.

Results

While exploring LT for intrahepatic cholangiocarcinoma dates to the 1990s, the initial outcomes were discouraging, marked by poor survival and high recurrence rates. Nevertheless, contemporary perspectives underscore a reinvigorated emphasis on extending the frontiers of LT indications within the context of the "oncologic era." The insights gleaned from examining explants, wherein incidental iCC was categorized as hepatocellular carcinoma in the preoperative period, have demonstrated comparable survival rates to small hepatocellular carcinoma. These findings substantiate the potential viability of LT as a curative alternative for iCC. Another investigated scenario pertains to "unresectable tumors with favorable biological behavior," LT presents a theoretical advantage by providing free margins without the concern of a small future liver remnant. The constraint of organ shortage persists, particularly in nations with low donation rates. LDLT emerges as a viable and secure alternative for treating iCC.

Conclusion

LDLT is an excellent option for augmenting the graft pool, particularly in carefully selected patients.

Early Graft Failure After Living-Donor Liver Transplant

BACKGROUND

Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed.

AIM

Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes.

METHODS

Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure.

RESULTS

During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001).

CONCLUSION

Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

Living Donor Liver Transplantation: Left Lobe or Right Lobe

Living Donor Liver Transplantation (LDLT) has seen great advancements since its inception in 1988. Herein, the nuances of LDLT are discussed spanning from donor evaluation to the recipient operation. Special attention is given to donor anatomy and graft optimization techniques in the recipient.

Transplantation of heterozygous familial hypercholesterolemia living donor liver resulting in early myocardial infarction: a possible dangerous link

Living donor liver transplantation (LDLT) is a lifesaving procedure that is often curative for several liver diseases. Familial hypercholesterolemia (FH) is a metabolic disease that results from an autosomal dominant mutation in the low-density lipoprotein receptor; yet, young patients with FH can live years without detection. Herein, we report a case of a patient who developed early myocardial infarction (MI) after having a transplant from a donor with undetected heterozygous FH. This was a 67-year-old female with non-alcoholic steatohepatitis-related liver cirrhosis, free from coronary artery disease, who underwent LDLT from her daughter, a 45-year-old female with no past medical history. One year post-transplant, she presented with an acute MI with a large atherosclerotic burden. Genetic analysis confirmed heterozygous FH in the donor but not in the recipient. This case emphasizes the importance of incorporating a thorough clinical history and lipid profile into pre-transplant testing for both the recipient and donor, as well as aggressive lipid-lowering therapy post-transplantation to avoid cardiovascular complications.

Risk factors for pre-transplantation bacteremia in adults with end-stage liver disease: Effects on outcomes of liver transplantation

BACKGROUND AND AIM

Limited data are available regarding pre-liver transplantation (LT) bacteremia in adults with end-stage liver disease. In this study, we investigated the risk factors independently associated with pre-LT bacteremia and their effects on clinical outcomes of LT.

METHODS

This retrospective study performed between 2010 and 2021 included 1287 LT recipients. The study population was categorized into patients with pre-LT bacteremia and those without pre-LT infection. Pre-LT bacteremia was defined as bacteremia detected within 90 days before LT.

RESULTS

Among 1287 LT recipients, 92 (7.1%) developed pre-LT bacteremia. The mean interval between bacteremia and LT was 28.3 ± 19.5 days. Of these 92 patients, seven (7.6%) patients died after LT. Of the 99 microorganisms isolated in this study, gram-negative bacteria were the most common microbes (72.7%). Bacteremia was mainly attributed to spontaneous bacterial peritonitis. The most common pathogen isolated was Escherichia coli (25.2%), followed by Klebsiella pneumoniae (18.2%), and Staphylococcus aureus (15.1%). Multivariate analysis showed that massive ascites (adjusted odds ratio [OR] 1.67, 95% confidence Interval [CI] 1.048-2.687) and a prolonged international normalized ratio for prothrombin time (adjusted OR 1.13, 95% CI 1.074-1.257) were independent risk factors for pre-LT bacteremia in patients with end-stage liver disease. Intensive care unit and in-hospital stay were significantly longer, and in-hospital mortality was significantly higher among LT recipients with pre-LT bacteremia than among those without pre-LT infection.

CONCLUSIONS

This study highlights predictors of pre-LT bacteremia in patients with end-stage liver disease. Pre-LT bacteremia increases the post-transplantation mortality risk.

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.

Unveiling the power of microenvironment in liver regeneration: an in-depth overview

The liver serves as a vital regulatory hub for various physiological processes, including sugar, protein, and fat metabolism, coagulation regulation, immune system maintenance, hormone inactivation, urea metabolism, and water-electrolyte acid-base balance control. These functions rely on coordinated communication among different liver cell types, particularly within the liver's fundamental hepatic lobular structure. In the early stages of liver development, diverse liver cells differentiate from stem cells in a carefully orchestrated manner. Despite its susceptibility to damage, the liver possesses a remarkable regenerative capacity, with the hepatic lobule serving as a secure environment for cell division and proliferation during liver regeneration. This regenerative process depends on a complex microenvironment, involving liver resident cells, circulating cells, secreted cytokines, extracellular matrix, and biological forces. While hepatocytes proliferate under varying injury conditions, their sources may vary. It is well-established that hepatocytes with regenerative potential are distributed throughout the hepatic lobules. However, a comprehensive spatiotemporal model of liver regeneration remains elusive, despite recent advancements in genomics, lineage tracing, and microscopic imaging. This review summarizes the spatial distribution of cell gene expression within the regenerative microenvironment and its impact on liver regeneration patterns. It offers valuable insights into understanding the complex process of liver regeneration.

Preliminary study of donor volume changes after dual-graft liver transplantation in rats

Dual-graft liver transplantation (DGLT) expands the pool of donors, ensures the safety of the donors, and treats a potential small for size syndrome (SFSS). However, some of the recipient graft showed atrophy. The cause and mechanism of the unbalanced proliferation and atrophy of dual grafts after clinical DGLT have not been clarified. We established and optimized the rat model of DGLT to explore the causes of growth unbalance. Continuously and dynamically observed bilateral graft volume and portal vein blood flow change by magnetic resonance imaging (MRI) and ultrasound (US). We detected liver function indexes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IBIL). Liver samples from receptors were obtained for morphology, and apoptosis was measured by RT-PCR and western blot. Optimization of the model improved the 7-day survival rate from former 58.3% to 87.5%, and the 30-day survival rate was 68.8%. The volume of the right graft gradually increased, and the left graft atrophied during the 30-day observation period. The portal blood flow of the left graft gradually decreased until the 30th day (0.13 ± 0.01 ml/s) compared with the sham group (0.63 ± 0.05 ml/s), and the right graft significantly increased on the 30th day (0.75 ± 0.11ml/s). The liver function initially increased and then recovered. The total volume (12.52 ± 1.60 ml vs 4.47 ± 0.08 ml) and weight (12.09 ± 1 g vs 4.91 ± 0.18 g) of the graft increased significantly compared to pre-transplantation and reached the level of the sham operation group on the 30th day. The volume and weight of the right graft increased more than those of the left graft (P < 0.05). There was more inflammatory cell infiltration in the left graft, and the right graft had obvious proliferation of hepatocytes and mature bile duct cells. Left grafts were more prone to apoptosis than right grafts (P < 0.05). In conclusion, growth of the right graft is superior to the left; after double liver transplantation, perfusion blood flow and apoptosis may be the reason contributing to the volume differences in dual grafts.

Post Living Donor Liver Transplantation Small-for-size Syndrome: Definitions, Timelines, Biochemical, and Clinical Factors for Diagnosis: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes.

METHODS

A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference.

RESULTS

The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed.

CONCLUSIONS

The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

Characteristics of living liver donors in a national referral hospital in Indonesia: a 13-year experience with living donor liver transplantation

Background

Hepatocellular carcinoma and biliary atresia lead to end-stage liver disease, which requires liver transplantation and is linked to increased mortality. Dr. Cipto Mangunkusumo Hospital is the national referral center in Indonesia and is the only center that routinely performs living donor liver transplantation (LDLT). This study presents the characteristics of living liver donors (LLDs) in Indonesia.

Methods

Using the LDLT registry, we conducted a retrospective analysis of all approved donors from 2010 to 2022. The variables included clinical characteristics of the donors, graft types, and intraoperative and postoperative characteristics.

Results

The LDLT rate has increased from 5.8 to 8.8 procedures/year in the last 8 years. The average age of the 76 LLDs was 31.8 years. They were predominantly female (59%) and lived within a family relationship (90%). Pediatric LDLT was more frequent than adult LDLT (88% vs. 12%, respectively). Most grafts (86%) were obtained by left lateral sectionectomy, with a median ratio of remnant liver volume to total liver volume of 79.5% (range, 47.7%-85.8%) and a mean graft-to-recipient weight ratio of 2.65%±1.21%. The median intensive care unit length of stay (LOS) was 2 days (range, 1-5 days) and the total hospital LOS was 7 days (range, 4-28 days). The complication rate was 23%. No donor mortality was reported.

Conclusions

LDLT in Indonesia has increased over the years. The shortage of donors for adult-to-adult liver transplantation is due to cultural differences and challenges in finding eligible donors. This study aims to explain the eligibility criteria of LLDs and contribute to creating a national policy.

Successful living donor liver transplantation from an HIV and HCV positive donor: report from the first case in the world

HIV (human-immunodeficiency-virus) and HCV (hepatitis-C-virus) infections cause millions of deaths across the world every year. Since the introduction of effective therapies for HIV, in the middle of 1990s, and HCV, after 2013, those two untreatable infections became completely controlled. Donor safety is the main goal in living donor liver transplantation (LDLT). An accurate predonation screening is mandatory for excluding risk factors related with any increase of donors' short-term and long-term morbidity. We present the first LDLT from a donor with both HIV and HCV previous infections. Donor and recipient did not experience any complication. Individuals with well controlled HIV/HCV infections and without any risk factors may be suitable for donation of a part of their healthy liver. Abstract video, http://links.lww.com/QAD/C833.

Impact of Older Donor Age on Recipient and Graft Survival After LDLT: The US Experience

BACKGROUND

The impact of selecting older donors for living donor liver transplantation (LDLT) in the United States is incompletely studied, particularly in light of the recent expansion of LDLT nationally.

METHODS

Adult LDLTs from January 01, 2005 to December 31, 2019 were identified using the United Network for Organ Sharing database. Multivariable Cox models evaluated living donor (LD) age as a predictor of LDLT recipient and graft survival. The impact of increasing donor age on recipient outcomes was compared between LD and deceased donor recipients. Donor postoperative outcomes were evaluated.

RESULTS

There were 3539 LDLTs at 65 transplant centers during the study period. Despite the recent expansion of LDLT, the proportion of LDs aged ≥50 y was stable. There were no clinically significant differences in recipient or donor characteristics by LD age group. LD age ≥50 y was associated with an adjusted hazard ratio of 1.49 ( P = 0.012) for recipient survival and 1.61 ( P < 0.001) for graft survival (vs LDs aged 18-29 y). The negative impact of increasing donor age on graft survival was more profound after LDLT than deceased donor liver transplantation (interaction P = 0.019). There was a possible increased rate of early donor biliary complications for donors >55 y (7.1% versus 3.1% for age <40 y; P = 0.156).

CONCLUSIONS

Increasing LD age is associated with decreased recipient and graft survival, although older donors still largely yield acceptable outcomes. Donor outcomes were not clearly impacted by increasing age, though this warrants further study.

Cumulative postoperative change in serum albumin levels and organ failure after living-donor liver transplantation: A retrospective cohort analysis

Many studies have reported that hypoalbuminemia could be associated with organ failure after liver transplantation. However, most of them focused on serum albumin levels measured at specific time points and not on the trend of serum albumin change. We investigated whether a cumulative postoperative change in serum albumin level up to postoperative day (POD) 5 is related to organ failure in patients who underwent living-donor liver transplantation (LDLT). Data of adult recipients who underwent LDLT between January 2016 and December 2020 at a single tertiary hospital were reviewed (n = 399). After screening, three patients were excluded because of insufficient data. A cumulative change in serum albumin level was demonstrated using the area under the threshold (AUT, threshold = 3.0 g/dL) of the serum albumin curve up to POD 5. Based on the AUT, the patients were divided into a high-decrease group (n = 156) and a low-decrease group (n = 240). All analyses were conducted using 1:1 propensity score matching. The primary endpoint was the Sequential Organ Failure Assessment (SOFA) score on POD 5. The secondary endpoints were postoperative hospital stay and postoperative 90-day mortality. A total of 162 patients were included. The SOFA score on POD 5 was significantly higher in the High-decrease group compared with the Low-decrease group (5.2 ± 2.6 vs. 4.1 ± 2.3; mean difference: 1.1, 95% CI: 0.3 to 1.8; P = 0.005). However, the length of postoperative hospital stay (P = 0.661) and 90-day mortality (P = 0.497) did not differ between the groups. In conclusion, a cumulative postoperative change in serum albumin level up to POD 5 could help predict postoperative organ failure on POD 5 in patients who underwent LDLT.

[Living related liver transplantation in the Republic of Uzbekistan: current status and development prospects]

OBJECTIVE

To analyze primary results of living related liver transplantation in the Republic of Uzbekistan.

MATERIAL AND METHODS

There were 44 living related transplantations of the right liver lobe in patients with decompensated liver failure between February 2018 and February 2023.

RESULTS

Uneventful postoperative period was observed in 17 (38.6%) recipients. Other 27 patients (61.4%) developed 47 various postoperative complications (1-3 events per a patient). Of these, 8 (18.2%) patients required early postoperative re-laparotomy. Among 44 patients, 9 (20.5%) ones died in early postoperative period, and one patient died in long-term period (3 years after transplantation) from chronic rejection under refusal to take immunosuppressive drugs. Early satisfactory results were obtained in 79.5% of patients, long-term favorable outcomes - in 77.3% of cases.

CONCLUSION

Engraftment rates and survival of recipients to a large extent depend on surgical strategy, baseline disease and clinical severity. The so-called "center effect" is essential at initial stages of implementation of the program.

Utilization of hepatitis B virus surface antigen positive grafts in liver transplantation: A matched study based on a national registry cohort

BACKGROUND AND AIM

Donor shortage has become worldwide limitation in liver transplantation (LT). Use of hepatitis B virus surface antigen positive (HBsAg+) donors could be an alternative source of donor organs. This study aims to investigate the safety and efficacy of LT using HBsAg+ liver grafts and associated long-term outcome.

METHODS

This was a retrospective study of adults LT registered in the database of the China Liver Transplant Registry between January 2015 and September 2018. By propensity score matching (1:1), 503 eligible patients who received HBsAg+ liver grafts were compared with 503 matched patients who received HBsAg- liver grafts.

RESULTS

The 1-, 3-, and 5-year patient survival rates were 81.52%, 72.04%, and 66.65% in HBsAg+ donor group, which were comparable with 83.93%, 77.27%, and 65.73% in HBsAg- donor group (P = 0.222). The 1-, 3-, and 5-year graft survival rates were also comparable between the two groups (81.49%, 71.45%, and 67.26% vs 83.62%, 77.11%, and 65.81%, respectively, P = 0.243). Most main complications were not increased in HBsAg+ donor group except for the retaining of HBsAg positivity after LT. Furthermore, transplanting HBsAg+ liver grafts did not result in inferior outcomes either in HBsAg+ or HBsAg- recipients. The risk of tumor recurrence after LT was not increased in hepatocellular carcinoma patients.

CONCLUSIONS

The outcomes of using HBsAg+ liver grafts were comparable with those of HBsAg- liver grafts. Our study provided strong evidence for the safe use of HBsAg+ grafts in LT to expand the donor liver pool.

Robotic Living Donor Right Hepatectomy: A Systematic Review and Meta-Analysis

The introduction of robotics in living donor liver transplantation has been revolutionary. We aimed to examine the safety of robotic living donor right hepatectomy (RLDRH) compared to open (ODRH) and laparoscopic (LADRH) approaches. A systematic review was carried out in Medline and six additional databases following PRISMA guidelines. Data on morbidity, postoperative liver function, and pain in donors and recipients were extracted from studies comparing RLDRH, ODRH, and LADRH published up to September 2020; PROSPERO (CRD42020214313). Dichotomous variables were pooled as risk ratios and continuous variables as weighted mean differences. Four studies with a total of 517 patients were included. In living donors, the postoperative total bilirubin level (MD: −0.7 95%CI −1.0, −0.4), length of hospital stay (MD: −0.8 95%CI −1.4, −0.3), Clavien−Dindo complications I−II (RR: 0.5 95%CI 0.2, 0.9), and pain score at day > 3 (MD: −0.6 95%CI −1.6, 0.4) were lower following RLDRH compared to ODRH. Furthermore, the pain score at day > 3 (MD: −0.4 95%CI −0.8, −0.09) was lower after RLDRH when compared to LADRH. In recipients, the postoperative AST level was lower (MD: −0.5 95%CI −0.9, −0.1) following RLDRH compared to ODRH. Moreover, the length of stay (MD: −6.4 95%CI −11.3, −1.5) was lower after RLDRH when compared to LADRH. In summary, we identified low- to unclear-quality evidence that RLDRH seems to be safe and feasible for adult living donor liver transplantation compared to the conventional approaches. No postoperative deaths were reported.

Living Donor Liver Transplantation vs. Split Liver Transplantation Using Left Lateral Segment Grafts in Pediatric Recipients: An Analysis of the UNOS Database

Split and LDLT in pediatric patients have the potential to decrease wait times and waitlist mortality. Using UNOS-STAR data, we compared outcomes of pediatric patients undergoing LDLT and SLT using LLS grafts. The baseline characteristics and post-operative outcomes were compared between groups. Actuarial graft and patient survival were analyzed with Kaplan-Meier curves. Between 2010 and 2019, 911 pediatric LT were included in the analysis (LD graft group, n = 508, split graft group, n = 403). LD graft recipients spent more time on the waitlist vs. the split graft group (60 (22–138) days vs. 46 (16–108) days; p = 0.007). LD recipients had a lower rate of graft failure, found in 9.8% of patients compared with 14.6% in the split graft group (p = 0.02). HAT was the most common graft failure cause, with similar rates. Graft and patient survival at 1-, 3-, and 5-years was comparable between LDLT and SLT. In subgroup analyses, patients with biliary atresia, those ≤10 kg or ≤10 years old receiving an LD graft showed improved graft survival. In conclusion, LDLT is associated with a lower rate of graft failure in pediatric patients. The use of LLS regardless of the type of donor is a safe way to facilitate access to transplantation to pediatric patients with acceptable short and long-term outcomes.

Long-term outcome after living donor liver transplantation compared to donation after brain death in autoimmune liver diseases: Experience from the European Liver Transplant Registry

Knowledge of living donor liver transplantation (LDLT) for autoimmune liver diseases (AILDs) is scarce. This study analyzed survival in LDLT recipients registered in the European Liver Transplant Registry with autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis (PSC) and the non-autoimmune disorder alcohol-related cirrhosis. In total, 29 902 individuals enrolled between 1998 and 2017 were analyzed, including 1003 with LDLT. Survival from >90 days after LDLT for AILDs in adults was 85.5%, 74.2%, and 58.0% after 5, 10, and 15 years. Adjusted for recipient age, sex, and liver transplantation era, adult PSC patients receiving LDLT showed increased mortality compared to donation after brain death (DBD) (hazard ratio [HR] = 1.95, 95% confidence interval [CI] = 1.36-2.80, p < .001). Pediatric PSC patients showed also increased mortality >90 days after LDLT compared to DBD (HR = 3.00, 95% CI 1.04-8.70, p = .043). Multivariate analysis identified several risk factors for death in adult PSC patients receiving LDLT including a male donor (HR = 2.49, p = .025). Adult PSC patients with LDLT versus DBD conferred increased mortality from disease recurrence (subdistribution hazard ratio [subHR] = 5.36, p = .001) and biliary complications (subHR = 4.40, p = .006) in multivariate analysis. While long-term outcome following LDLT for AILD is generally favorable, PSC patients with LDLT compared to DBD might be at increased risk of death.

Why are there so many liver transplants from living donors in Asia and so few in Europe and the US?

Acceptance of liver transplantation (LT) as an established treatment modality for end-stage liver disease has led to an exponential increase in the demand for organs, resulting in an ever-increasing gap between the availability of organs and the number of sick patients waiting for them. Interestingly, influenced by cultural, socio-economic and other constraints, the West and the East have attempted to address this problem of shortage in different ways. Living donor LT (LDLT) became polarised to the East with over 90% of LT in this region being LDLT. On the other hand, the West chose to concentrate their efforts on optimising the use of cadaveric livers with techniques such as split LT, or by using extended criteria donors (including donation after cardiac death donors) and machine perfusion devices etc. Consequently, LDLT did not find the widespread acceptance it did in the East and hence over 90% of all LT are DDLT in this region. We review each regions' perspective and attempt to provide a globally viable roadmap to bridge the widening gap between the demand and availability of livers for LT.

Application of Magnetic Resonance Imaging in Liver Biomechanics: A Systematic Review

MRI-based biomechanical studies can provide a deep understanding of the mechanisms governing liver function, its mechanical performance but also liver diseases. In addition, comprehensive modeling of the liver can help improve liver disease treatment. Furthermore, such studies demonstrate the beginning of an engineering-level approach to how the liver disease affects material properties and liver function. Aimed at researchers in the field of MRI-based liver simulation, research articles pertinent to MRI-based liver modeling were identified, reviewed, and summarized systematically. Various MRI applications for liver biomechanics are highlighted, and the limitations of different viscoelastic models used in magnetic resonance elastography are addressed. The clinical application of the simulations and the diseases studied are also discussed. Based on the developed questionnaire, the papers' quality was assessed, and of the 46 reviewed papers, 32 papers were determined to be of high-quality. Due to the lack of the suitable material models for different liver diseases studied by magnetic resonance elastography, researchers may consider the effect of liver diseases on constitutive models. In the future, research groups may incorporate various aspects of machine learning (ML) into constitutive models and MRI data extraction to further refine the study methodology. Moreover, researchers should strive for further reproducibility and rigorous model validation and verification.

Noninvasive Estimation of Hepatic Steatosis by Controlled Attenuation Parameter in Living Donor Liver Transplant

OBJECTIVES

Estimation of liver fat among living donor candidates is necessary before living donor liver transplant. This study aimed to investigate the usefulness of the controlled attenuation parameter compared with liver biopsy for pretransplant estimation of hepatic steatosis in living liver donors.

MATERIALS AND METHODS

In this retrospective study, we included all individuals who underwent transient elastography with controlled attenuation parameter and ultrasonography-guided liver biopsy as a part of donor evaluations before living donor liver transplant. Clinical and laboratory data of living donor candidates were reviewed and collected.

RESULTS

Of 49 donor candidates included in this study, 21 (42.9%) had different degrees of hepatic macrosteatosis. Of the 21 donor candidates who had hepatic steatosis in liver biopsy, 13 individuals were diagnosed to have steatosis in transient elastography. Of the 28 donor candidates without hepatic steatosis in liver biopsy, 26 individuals showed no steatosis in transient elastography (odds ratio: 21.12; 95% CI, 3.91- 114.08; P < .001). Controlled attenuation parameter was useful in discriminating presence (P = .001) and grade of hepatic steatosis (P = .009) compared with liver biopsy with good sensitivity and specificity.

CONCLUSIONS

The controlled attenuation parameter is a noninvasive method for detection of hepatic steatosis in living donor candidates and can be used as an adjunct to liver biopsy for screening of living donor candidates before liver transplant.

Bilateral continuous erector spinae plane block using a programmed intermittent bolus regimen versus intrathecal morphine for postoperative analgesia in living donor laparoscopic hepatectomy: A randomized controlled trial

STUDY OBJECTIVE

To determine if continuous bilateral erector spinae plane (ESP) blocks would improve the postoperative analgesia in the first 48 h after laparoscopic donor hepatectomy, compared to intrathecal morphine (ITM).

DESIGN

Prospective, randomized controlled trial.

SETTING

A single tertiary care center from October 2019 and September 2020.

PATIENTS

A total of 60 donors scheduled to undergo elective laparoscopic right hepatectomy.

INTERVENTIONS

Sixty donors were randomized to receive either bilateral continuous T8 ESP blocks with a programmed intermittent bolus regimen of 10 mL 0.2% ropivacaine every 3 h for 48 h (n = 30) or 400 μg ITM (n = 30), in addition to IV fentanyl PCA and multimodal analgesia.

MEASUREMENTS

The primary outcome was cumulative opioid consumption over the first 48 h, expressed as IV morphine equivalents. Secondary outcomes included pain scores, Quality of Recovery-15 scores, ambulation within 24 h, time to first flatus, and opioid-related adverse drug events over 72 h.

MAIN RESULTS

Fifty-nine donors were analyzed. Cumulative 48-h opioid consumption was similar between the ITM and ESP groups (29.8 ± 18.2 vs. 35.1 ± 21.9 mg, mean difference (ESP-ITM) (95% CI), 5.3 (-11.5 to 22) mg; p > 0.99). Resting pain scores at 48 and 72 h postoperatively were significantly lower in the ESP group (0 [0-2] vs. 3 [1.5-3], and 0 [0-2] vs. 3 [1-3] respectively, both p<0.001) (Goldaracena and Barbas, 2019; Ko et al., 2009; Choi et al., 2007 [1-3]) respectively, both p < 0.001). The ESP group had significantly lower incidences of postoperative nausea, vomiting, and pruritus at all timepoints. There were no differences in recovery outcomes.

CONCLUSIONS

Continuous ESP blocks did not reduce cumulative 48-h opioid consumption compared to 400 μg ITM after laparoscopic donor hepatectomy, but it was associated with a significantly reduced risk of postoperative nausea, vomiting and pruritus.

CLINICAL TRIAL NUMBER AND REGISTRY URL

Clinical Trial Registry of Korea; https://cris.nih.go.kr/cris/index.jsp and identifier: KCT0004313; date of registration: October 15, 2019; principal investigator's name: Justin Sangwook Ko.

"The use of bilateral continuous erector spinae plane blocks for postoperative analgesia after right-sided living donor hepatectomy: A feasibility study"

BACKGROUND

Postoperative pain after living donor hepatectomy is significant. Postoperative coagulopathy may limit the use of epidural analgesia, the gold standard for pain control in abdominal surgery. The erector spinae plane block (ESPB) is a novel regional anesthesia technique that has been shown to provide effective analgesia in abdominal surgery. In this study, we examined the effect of continuous ESPB, administered via catheters, on perioperative opioid requirements after right living donor hepatectomies for liver transplantation.

METHODS

We performed a retrospective cohort study in patients undergoing right living donor hepatectomy. Twenty-four patients who received preoperative ESPB were compared to 51 historical controls who did not receive regional anesthesia. The primary endpoint was the total amount of oral morphine equivalents (OMEs) required on the day of surgery and postoperative day (POD) 1.

RESULTS

Patients in the ESPB group required a lower total amount of OMEs on the day of surgery and POD 1 [141 (107-188) mg] compared the control group [293 (220-380) mg; P < .001].

CONCLUSIONS

The use of continuous ESPB significantly reduced opioid consumption following right living donor hepatectomy.

Liver structural transformation after partial hepatectomy and repeated partial hepatectomy in rats: A renewed view on liver regeneration

BACKGROUND

The phenomenon of liver regeneration after partial hepatectomy (PH) is still a subject of considerable interest due to the increasing frequency of half liver transplantation on the one hand, and on the other hand, new surgical approaches which allow removal of massive space-occupying hepatic tumors, which earlier was considered as inoperable. Interestingly, the mechanisms of liver regeneration are extensively studied after PH but less attention is paid to the architectonics of the regenerated organ. Because of this, the question “How does the structure of regenerated liver differ from normal, regular liver?” has not been fully answered yet. Furthermore, almost without any attention is left the liver's structural transformation after repeated hepatectomy (of the re-regenereted liver).

AIM

To compare the architectonics of the lobules and circulatory bed of normal, re-generated and re-regenerated livers.

METHODS

The livers of 40 adult, male, albino Wistar rats were studied. 14 rats were subjected to PH - the 1^st study group (SG1); 10 rats underwent repeated PH – the 2^nd study group (SG2); 16 rats were subjected to sham operation - control group (CG); The livers were studied after 9 months from PH, and after 6 months from repeated PH. Cytological (Schiff reaction for the determination of DNA concen-tration), histological (H&E, Masson trichrome, CK8 Immunohistochemical marker, transparent slides after Indian Ink injection, ), morphometrical (hepatocytes areas, perimeters and ploidy) and Electron Microscopical (Scanning Electron Microscopy of corrosion casts) methods were used.

RESULTS

In the SG1 and SG2, the area of hepatocytes and their perimeter are increased compared to the CG (P < 0.05). However, the areas and perimeters of the hepatocytes of the SG₁ and SG₂ groups reveal a lesser difference. In regenerated (SG₁) and re-regenerated (SG₂) livers, the hepatocytes form the remodeled lobules, which size (300-1200 µm) exceeds the sizes of the lobules from CG (300-600 µm). The remodeled lobules (especially the “mega-lobules” with the sizes 1000-1200 µm) contain the transformed meshworks of the sinusoids, the part of which is dilated asymmetrically. This meshwork might have originated from the several portal venules (interlobular and/or inlet). The boundaries between the adjacent lobules (including mega-lobules) are widened and filled by connective tissue fibers, which gives the liver parenchyma a nodular look. In SG₂ the unevenness of sinusoid diameters, as well as the boundaries between the lobules (including the mega-lobules) are more vividly expressed in comparison with SG₁. The liver tissue of both SG₁ and SG₂ is featured by the slightly expressed ductular reaction.

CONCLUSION

Regenerated and re-regenerated livers in comparison with normal liver contain hypertrophied hepatocytes with increased ploidy which together with transformed sinusoidal and biliary meshworks form the remodeled lobulli.

Bilateral single-injection erector spinae plane block versus intrathecal morphine for postoperative analgesia in living donor laparoscopic hepatectomy: a randomized non-inferiority trial

BACKGROUND

Intrathecal morphine (ITM) provides effective postoperative analgesia in living donor hepatectomy but has significant adverse effects. Studies support the efficacy of erector spinae plane (ESP) blocks in laparoscopic abdominal surgery; we therefore hypothesized that they would provide non-inferior postoperative analgesia compared with ITM and reduce postoperative nausea/vomiting and pruritus. We conducted a randomized, controlled, non-inferiority trial to compare the analgesic efficacy of ITM and bilateral single-injection ESP blocks in laparoscopic donor hepatectomy.

METHODS

Fifty-four donors were randomized to receive bilateral ESP blocks with 20 mL 0.5% ropivacaine (n=27) or 400 µg ITM (n=27). Primary outcome was resting pain score 24 hours postoperatively measured on an 11-point numeric rating scale. The prespecified non-inferiority limit was 1. Incidences of postoperative nausea/vomiting and pruritus were assessed.

RESULTS

The mean treatment difference (ESP-ITM) in the primary outcome was 1.2 (95% CI 0.7 to 1.8). The 95% CI upper limit exceeded the non-inferiority limit. Opioid consumption and all other pain measurements were similar between groups up to 72 hours postoperatively. The ESP group had significantly lower incidences of postoperative vomiting (p=0.002) and pruritus (p<0.001).

CONCLUSIONS

Bilateral single-injection ESP blocks resulted in higher resting pain scores 24 hours postoperatively compared with ITM and thus did not meet the study definition of non-inferiority. However, the pain intensity with ESP blocks was mild (mean pain scores <3/10) and associated with reduced incidence of postoperative vomiting and pruritus. It warrants further investigation as an analgesic option after laparoscopic living donor hepatectomy.

TRIAL REGISTRATION NUMBER

KCT0003191.