Which is better to use "body weight" or "standard liver weight", for predicting small-for-size graft syndrome after living donor liver transplantation?

The impact of perioperative synbiotics treatment in living-donor liver transplantation after induction of early enteral nutrition

PURPOSE

Infectious complications, particularly post-transplant sepsis, have a critical impact on postoperative outcomes. This study examined the effects of perioperative synbiotic treatment on postoperative outcomes in patients receiving early enteral nutrition.

METHODS

We reviewed 210 living-donor liver transplantation procedures and retrospectively analyzed the postoperative outcomes with and without perioperative synbiotic treatment (live lactic acid bacteria, bifidobacteria, and oligosaccharides) 5 days before and after living-donor liver transplantation.

RESULTS

The synbiotic group (n = 34) had significantly fewer male donors (38.2% vs. 61.9%, p = 0.011) and a higher proportion of ABO-incompatible grafts (52.9% vs. 25.6%, p = 0.021) than the non-synbiotic group (n = 176). The incidence of sepsis was significantly lower in the synbiotic group than in the non-synbiotic group (0% vs. 7.4%, p = 0.029), with a lower incidence rate of sepsis due to bacteremia with intestinal bacteria (0% vs. 4.6%, p = 0.089). There were no significant differences in the proportions of acute rejection, small-for-size graft syndrome, or postoperative liver function between the two groups. Furthermore, there was no significant difference in the graft survival rates after LDLT between two groups. (p = 0.24).

CONCLUSION

Perioperative synbiotic treatment prevents post-transplant sepsis, even with early enteral nutrition.

Prediction and management of small-for-size syndrome in living donor liver transplantation

Small-for-size syndrome (SFSS) remains a critical challenge in living donor liver transplantation (LDLT), characterized by graft insufficiency due to inadequate liver volume, leading to significant postoperative morbidity and mortality. As the global adoption of LDLT increases, the ability to predict and manage SFSS has become paramount in optimizing recipient outcomes. This review provides a comprehensive examination of the pathophysiology, risk factors, and strategies for managing SFSS across the pre-, intra-, and postoperative phases. The pathophysiology of SFSS has evolved from being solely volume-based to incorporating portal hemodynamics, now recognized as small-for-flow syndrome. Key risk factors include donor-related parameters like age and graft volume, recipient-related factors such as MELD score and portal hypertension, and intraoperative factors related to venous outflow and portal inflow modulation. Current strategies to mitigate SFSS include careful graft selection based on graft-to-recipient weight ratio and liver volumetry, surgical techniques to optimize portal hemodynamics, and novel interventions such as splenic artery ligation and hemiportocaval shunts. Pharmacological agents like somatostatin and terlipressin have also shown promise in modulating portal pressure. Advances in 3D imaging and artificial intelligence-based volumetry further aid in preoperative planning. This review emphasizes the importance of a multifaceted approach to prevent and manage SFSS, advocating for standardized definitions and grading systems. Through an integrated approach to surgical techniques, hemodynamic monitoring, and perioperative management, significant strides can be made in improving the outcomes of LDLT recipients. Further research is necessary to refine these strategies and expand the application of LDLT, especially in challenging cases involving small-for-size grafts.

What is the crux of successful living-donor liver transplantation for recipients aged 70 and beyond?

Aim

There is limited evidence regarding the feasibility of living-donor liver transplantation (LDLT) for patients aged over 70. The aims of this study were to assess postoperative outcomes in elderly recipients and to ascertain the potential feasibility and acceptability of LDLT.

Methods

Data were collected from 762 recipients, including 26 in the elderly group (aged ≥70) and 736 in the younger group (aged <70), and reviewed even by propensity score matching (PSM).

Results

No significant differences were observed in the frequency of postoperative complications between the two groups. Additionally, both groups exhibited a comparable 30-day mortality rate after LDLT (3.9% in both) and similar hospital stays (36 days vs. 40 days). The 1-, 3-, and 5-year graft survival rates in the elderly group were 92.0%, which was comparable to those in the younger group (p = 0.517), as confirmed by PSM. Notably, all donors for elderly patients were the children of the recipients, with an average age of 41.6 years, and grafts from donors aged ≥50 years were not utilized, signifying the use of high-quality grafts. Our inclusion criterion for elderly recipients was strictly defined as an ECOG-PS score of 0-2, which played a pivotal role in achieving favorable postoperative outcomes.

Conclusion

LDLT can be performed safely for elderly patients aged 70 years or older, provided they have a preserved PS and receive high-quality grafts from younger donors, inevitably all children of elderly recipients. This approach yields acceptable long-term outcomes. Consequently, age alone should not serve as an absolute contraindication for LDLT.

Is preoperative weight reduction of living-donor liver transplant recipients and donors harmful to postoperative outcomes?

PURPOSE

Although the incidence of recipients and donors with overweight and obesity is increasing worldwide, few reports have focused on outcomes of preoperative weight reduction (WR) in living-donor liver transplantation (LDLT). Therefore, we examined the outcomes and the impact of WR on the postoperative course.

METHODS

We analyzed 217 consecutive LDLT procedures performed from 2017 to 2022. We divided the recipients and donors into a WR group and non-WR group.

RESULTS

Twenty-two recipients (10.1%) achieved WR (preoperative recipient WR [RWR] group), reducing their weight by 6.8% ± 6.0% within 2.2 ± 1.4 months with a significant decrease in body mass index (BMI) (P < .0001). The RWR group showed no significant differences in short-term postoperative outcomes (operative factors, postoperative liver function tests, amount of ascites, and morbidity) or in the graft survival rate as a long-term outcome (P = .24) compared with the non-RWR group. Forty-one donors (18.9%) achieved WR (preoperative donor WR [DWR] group), reducing their weight by 9.7% ± 6.3% within 3.2 ± 5.8 months with a significant decrease in BMI (P < .0001). Compared with the non-DWR group, the DWR group showed no significant differences in short-term postoperative outcomes between themselves and recipients or in the graft survival rate (P = .49). Furthermore, WR resulted in an increase to 32 donor-eligible and 6 recipient-eligible patients.

CONCLUSION

WR in LDLT recipients and donors had no harmful effect on postoperative outcomes and should lead to increase recipients' chance of undergoing LDLT and to expand the donor pool.

"Reduced Size Liver Grafts in Pediatric Liver Transplantation; Technical Considerations"

Liver transplantation (LT) has become a vital treatment option for children with end-stage liver disease. Left lateral segment (LLS) grafts are particularly common in split and living donor LT for pediatric patients. However, challenges arise in small infants receiving LLS grafts, primarily due to graft-size mismatches, resulting in "large-for-size" grafts. To overcome this issue, the practice of further reducing grafts from the LLS to diminish graft thickness has been explored. Currently, the indication for reducing the thickness of LLS grafts includes recipients with a body weight (BW) under 5.0 kg, neonates with acute liver failure, or those with metabolic liver disease. At the National Center for Child Health and Development in Tokyo, Japan, among 131 recipients of reduced-size LLS grafts, a remarkable 15-year graft survival rate of 89.9% has been achieved in small infants. This success indicates that with experience and refinement of the technique, there's a trend towards improved graft survival in recipients with reduced-thickness LLS grafts. This advancement underscores the importance of BW-appropriate methods in graft selection to ensure exceptional outcomes in vulnerable pediatric patients in need of LT. These techniques' ongoing development and refinement are crucial in enhancing the survival rates and overall outcomes for these young patients.

Aborted living-donor liver transplantation in the real-world setting, lessons from 13 937 cases of Vanguard Multi-center Study of International Living Donor Liver Transplantation Group

There are exceedingly uncommon but clearly defined situations where intraoperative abortions are inevitable in living-donor liver transplantation (LDLT). This study aimed to summarize the cases of aborted LDLT and propose a strategy to prevent abortion or minimize donor damage from both recipient and donor sides. We collected data from a total of 43 cases of aborted LDLT out of 13 937 cases from 7 high-volume hospitals in the Vanguard Multi-center Study of the International Living Donor Liver Transplantation Group and reviewed it retrospectively. Of the 43 cases, there were 24 recipient-related abortion cases and 19 donor-related cases. Recipient-related abortions included pulmonary hypertension (n = 8), hemodynamic instability (n = 6), advanced hepatocellular carcinoma (n = 5), bowel necrosis (n = 4), and severe adhesion (n = 1). Donor-related abortions included graft steatosis (n = 7), graft fibrosis (n = 5), primary biliary cholangitis (n = 3), anaphylactic shock (n = 2), and hemodynamic instability (n = 2). Total incidence of aborted LDLT was 0.31%, and there was no remarkable difference between the centers. A strategy to minimize additional donor damage by delaying the donor's laparotomy or trying to open the recipient's abdomen with a small incision should be effective in preventing some causes of aborted LDLT, such as pulmonary hypertension, advanced cancer, and severe adhesions.

Treatment strategy for hepatocellular carcinoma recurrence in the transplant era: Focusing on the Japan criteria

PURPOSE

To clarify the Japan criteria (JC), as proposed in 2019, in order to identify the most appropriate treatment methods for hepatocellular carcinoma (HCC) recurrence and assess the feasibility of pre-living donor liver transplantation (LDLT) downstaging within these criteria.

METHODS

The subjects of this study were 169 LDLT patients with HCC recurrence. We performed univariate and multivariate analyses of the factors contributing to HCC recurrence after LDLT and clarified the post-transplant outcomes of pre-LDLT downstaging.

RESULTS

Univariate and multivariate analysis identified beyond the JC (p = 0.0018) and a neutrophil-to-lymphocyte ratio > 2.01 (p = 0.029) as independent risk factors. Patients who met the JC had significantly higher recurrence-free and overall survival rates after LDLT (p < 0.0001) than those who did not (p = 0.0002). The post-transplant outcomes of patients within the JC after downstaging were significantly better than those of patients beyond the JC (p = 0.034) and equivalent to those within the JC without downstaging.

CONCLUSION

Even for HCC recurrence, the JC could play an important role in deciding on the best treatment strategy, and downstaging within the JC had good post-transplant outcomes.

Optimal graft size in pediatric living donor liver transplantation: How are children different from adults?

BACKGROUND

Pediatric liver transplantation is an established treatment for end-stage liver disease in children. However, it is still posing relevant challenges, such as optimizing the graft selection according to the recipient size. Unlike adults, small children tolerate large-for-size grafts and insufficient graft volume might represent an issue in adolescents when graft size is disproportionate.

METHODS

Graft-size matching strategies over time were examined in pediatric liver transplantation. This review traces the measures/principles put in place to prevent large-for-size or small-for-size grafts in small children to adolescents with a literature review and an analysis of the data issued from the National Center for Child Health and Development, Tokyo, Japan.

RESULTS

Reduced left lateral segment (LLS; Couinaud's segment II and III) was widely applicable for small children less than 5 kg with metabolic liver disease or acute liver failure. There was significantly worse graft survival if the actual graft-to-recipient weight ratio (GRWR) was less than 1.5% in the adolescent with LLS graft due to the small-for-size graft. Children, particularly adolescents, may then require larger GRWR than adults to prevent small-for-size syndrome. The suggested ideal graft selections in pediatric LDLT are: reduced LLS, recipient body weight (BW) < 5.0 kg; LLS, 5.0 kg ≤ BW < 25 kg; left lobe (Couinaud's segment II, III, IV with middle hepatic vein), 25 kg ≤ BW < 50 kg; right lobe (Couinaud's segment V, VI, VII, VIII without middle hepatic vein), 50 kg ≤ BW. Children, particularly adolescents, may then require larger GRWR than adults to prevent small-for-size syndrome.

CONCLUSION

Age-appropriate and BW-appropriate strategies of graft selection are crucial to secure an excellent outcome in pediatric living donor liver transplantation.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Pure Laparoscopic Versus Open Right Hepatectomy in Living Liver Donors: Graft Weight Discrepancy

BACKGROUND Accurate volumetric evaluation of donors' livers before surgery is crucial for successful living-donor liver transplantation. However, there are few studies on the volumetric evaluation in the recently popularized pure laparoscopic donor hepatectomy method, in contrast to the number of studies for conventional donor hepatectomy. We aimed to analyze the difference between estimated graft weight and actual graft weight in pure laparoscopic donor right hepatectomy (PLDRH) and conventional donor right hepatectomy (CDRH) procedures. MATERIAL AND METHODS The medical records of 612 donors who underwent right hepatectomy in living-donor liver transplantation between January 2014 and December 2020 were retrospectively reviewed. The CDRH group targeted patients from January 2014 to October 2015, and the PLDRH group targeted patients from March 2016 to December 2020. RESULTS There were 119 and 376 donors who underwent CDRH and PLDRH, respectively. Although there was no significant difference in the estimated graft weights (P=0.994) and actual graft weights (P=0.489) between the groups, the estimated graft weights were significantly higher than the actual graft weights in both groups. However, the estimated graft weight and actual graft weight showed linear correlations in both the CDRH (r=0.81, P<0.001) and PLDRH (r=0.76, P<0.001) groups, with the CDRH group having greater linearity. CONCLUSIONS The estimates of graft weight were similar between the 2 groups. However, since the actual graft weight tended to be smaller in the PLDRH group, this should be considered before surgery.

Low syntaxin 17 expression in donor liver is associated with poor graft prognosis in recipients of living donor liver transplantation

AIM

Liver transplantation (LT) is the only curative therapy for decompensated liver cirrhosis. For recipients of living donor LT (LDLT), restoration of liver function after transplantation is highly dependent on liver regenerative capacity, which requires large amounts of intracellular energy. Mitochondrial metabolism provides a stable supply of adenosine 5'-triphosphate (ATP) for liver regeneration. Mitophagy is a selective process in which damaged, non-functional mitochondria are degraded and replaced with new functional mitochondria. We investigated the relationship between expression of Syntaxin17 (STX17), a key protein in mitophagy regulation, in donor livers and graft survival.

METHODS

We examined STX17 expression in grafts from 143 LDLT donors who underwent right lobe resection and investigated the relationship between STX17 expression and graft function. We investigated the correlations among STX17 expression, mitochondrial membrane potential and cell proliferation, using a STX17-knockdown hepatocyte cell line.

RESULTS

Recipients transplanted with low STX17-expression grafts had significantly lower graft survival rates than recipients transplanted with high STX17-expression grafts (88.9% vs. 100%, p < 0.01). Multivariate analysis showed that low STX17 expression (HR: 10.7, CI: 1.29-88.0, p < 0.05) and the absence of splenectomy (HR: 6.27, CI: 1.59-24.8, p < 0.01) were independent predictive factors for small-for-size graft syndrome, which is the severe complication in LDLT. In the vitro experiments, the percentage of depolarized damaged mitochondria was increased in the STX17-knockdown hepatocyte cell line, suggesting decreased mitophagy and ATP synthesis. Cell proliferation was significantly decreased in the STX17-knockdown hepatocyte cell line.

CONCLUSION

STX17 contributes to mitophagy and maintenance of mitochondrial function in hepatocytes and may be a predictor of graft dysfunction in LDLT patients.