Portal flow modulation in living donor liver transplantation: review with a focus on splenectomy

What Are Risk Factors for Graft Loss in Patients Who Underwent Simultaneous Splenectomy During Living-donor Liver Transplantation?

BACKGROUND

The consensus that portal venous pressure modulation, including splenectomy (Spx), prevents portal hypertension-related complications after living-donor liver transplantation (LDLT) has been established. However, little evidence about the risk factors for graft loss after simultaneous Spx during LDLT is available. This study aimed to identify the independent predictors of graft loss after simultaneous Spx during LDLT.

METHODS

Data of 655 recipients who underwent LDLT between 1997 and 2021 were collected and separated into the simultaneous Spx group (n = 461) and no-Spx group (n = 194).

RESULTS

The simultaneous Spx group had significantly lower serum total bilirubin levels, drained ascites volumes, and prothrombin time-international normalized ratios on postoperative day 14 than the no-Spx group ( P  < 0.001 for each). Incidences of small-for-size graft syndrome ( P  < 0.001), acute cellular rejection ( P  = 0.002), and sepsis ( P  = 0.007) were significantly lower in the Spx group. Graft survival of the Spx group was significantly better than that of the no-Spx group ( P  < 0.001; hazard ratio [HR], 1.788; 95% confidence interval, 1.214-2.431). A multivariate analysis revealed that 3 variables, platelet count ≤4.0 × 10 4 /mm 3 ( P  = 0.029; HR, 2.873), donor age ≥60 y old ( P  = 0.013; HR, 6.693), and portal venous pressure at closure ≥20 mm Hg ( P  = 0.010; HR, 3.891), were independent predictors of graft loss within 6 mo after simultaneous Spx during LDLT.

CONCLUSIONS

Spx is a safe inflow modulation procedure with a positive impact on both postoperative complications and prognosis for most patients. However, patients with the 3 aforementioned independent factors could experience graft loss after LDLT.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

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.

Auxiliary Partial Orthotopic Liver Transplant as a Rescue Procedure for Acute Liver Failure with Extra-Small-for-Size Grafts: A Report of 2 Cases

Auxiliary partial orthotopic liver transplant is a complex technique whereby a partial liver graft is transplanted in the orthotopic position, leaving behind a portion of the native liver. In acute liver failure, auxiliary partial orthotopic liver transplant serves as a rescue therapy and bridge for the native liver to regenerate. Auxiliary partial orthotopic liver transplant was initially considered a technically challenging procedure with inferior results versus orthotopic liver transplant. However, advancements in surgical techniques have led to improved results with auxiliary partial orthotopic liver transplant. Auxiliary partial orthotopic liver transplant is now increasingly accepted as a valid treatment option for acute liver failure. We present 2 cases of acute liver failure treated with auxiliary partial orthotopic liver transplant using an extra-small-for-size graft. The first case was a 12-year-old female patient who presented with druginduced acute liver failure and required an auxiliary partial orthotopic liver transplant with an extra-small left lobe graft (graft-to-recipient weight ratio of 0.45). The second case was a 23-year-old male patient with acute liver failure of unknown etiology who underwent an auxiliary partial orthotopic liver transplant with a small right lobe graft (graft-torecipient weight ratio of 0.5). In both cases, computed tomography liver volumetry was performed to determine the appropriate graft size for the recipient. Both patients underwent successful auxiliary partial orthotopic liver transplants, with good postoperative recovery. Follow-up examinations showed satisfactory liver function without evidence of graft failure or rejection. Auxiliary partial orthotopic liver transplant using extra-small grafts can be an effective treatment option for acute liver failure when no other suitable option exists, including as a rescue procedure for small grafts. However, careful patient selection and surgical planning are essential to ensure successful outcomes.

Nodular Regenerative Hyperplasia Is Not a Rare Condition After Liver Transplantation: Incidence, Predictive Factors, and Impact on Survival

BACKGROUND

The objectives of this study were to evaluate incidence and to identify the risk factors of occurrence and the predictive factors of symptomatic forms of nodular regenerative hyperplasia (NRH) after liver transplantation (LT).

METHODS

To identify risk factors of NRH following LT, we included 1648 patients transplanted from 2004 to 2018 and compared the patients developing NRH after LT to those who did not. To identify predictive factors of symptomatic NRH, we selected 115 biopsies displaying NRH and compared symptomatic to asymptomatic forms. Symptomatic NRH was defined as the presence of ascites, esophageal varices, hepatic encephalopathy, portal thrombosis, retransplantation, or death related to NRH.

RESULTS

The incidence of NRH following LT was 5.1%. In multivariate analysis, the independent factor of developing NRH after LT was the donor's age (odds ratio [OR] = 1.02; confidence interval, 1.01-1.03; P = 0.02). Symptomatic forms occurred in 29 (25.2%) patients: 19 (16.5%) patients presented with ascites, 13 (11.3%) with esophageal varices, 4 (3.5%) with hepatic encephalopathy, and 8 (7%) with portal thrombosis. The median period before the onset of symptoms was 8.4 (1.5-11.3) y after LT. The spleen size at diagnosis/before LT ratio (OR = 12.5; 114.17-1.37; P = 0.0252) and thrombectomy during transplantation (OR = 11.17; 1.48-84.11; P = 0.0192) were associated with symptomatic NRH in multivariate analysis.

CONCLUSIONS

NRH following LT is frequent (5.1%) and leads to symptomatic portal hypertension in 25.2% of patients. Using older grafts increases the risk of developing NRH after LT. Clinicians should screen for signs of portal hypertension, particularly in measuring spleen size.

Technical challenges in LDLT - Overcoming small for size syndrome and venous outflow reconstruction

Living Donor Liver Transplantation (LDLT) emerged as an alternative treatment option for patients with end-stage liver disease waiting for an organ from a deceased donor. In addition to allowing for a faster access to transplantation, LDLT provides improved recipient outcomes when compared to deceased donor LT. However, it represents a more complex and demanding procedure for the transplant surgeon. In addition to a comprehensive preoperative donor assessment and stringent technical considerations during the donor hepatectomy to ensure upmost donor safety, the recipient procedure also comes with intrinsic challenges during LDLT. A proper approach during both procedures will result in favorable donor and recipient's outcomes. Hence, it is critical for the transplant surgeon to know how to overcome such technical challenges and avoid deleterious complications. One of the most feared complications following LDLT is small-for-size syndrome (SFSS). Although, surgical advances and deeper understanding of the pathophysiology behind SFSS has allowed for a safer implementation of LDLT, there is currently no consensus on the best strategy to prevent or manage this complication. Therefore, we aim to review current practices in technically challenging situations during LDLT, with a particular focus on management of small grafts and venous outflow reconstructions, as they possess one of the biggest technical challenges faced during LDLT.

Predictive Factors for the Resectable Type of Hepatocellular Carcinoma Recurrence After Living Donor Liver Transplant

Recurrence of hepatocellular carcinoma (HCC) after living donor liver transplant (LDLT) is an essential factor defining prognosis, and surgical resection is the only curative treatment. However, the factors that define whether surgical resection is possible remain unclear. Here, we compared resectable and unresectable HCC recurrence cases after LDLT and examined factors that determine whether surgical resection is possible. Resectable (n = 17) and unresectable (n = 14) groups among 264 patients who underwent LDLT for HCC from January 1999 to March 2020 were compared and examined for recurrence type, prognosis, and clinicopathologic factors. Overall survival after LDLT (median, 8.5 vs 1.7 years, P < .01) was significantly longer in the resectable group. In univariate analysis, female recipient rate, lymphocyte to monocyte ratio (LMR) ≥2.75, and tumor size ≤5.0 cm were significantly higher in the resectable group. Younger donors, lower Model for End-Stage Liver Disease scores, lower graft volume, and lower graft volume to standard liver volume ratio were evident in the resectable group. In multivariate analysis, female recipient rate (P = .0034) and LMR ≥2.75 (P = .0203) were independent predictive factors for resectable HCC recurrence after LDLT. Female recipient and LMR ≥2.75 before transplant could predict the surgically resectable type of HCC recurrence after LDLT.

Volume and flow modulation strategies to mitigate post-hepatectomy liver failure

INTRODUCTION

Post hepatectomy liver failure is the most common cause of death following major hepatic resections with a perioperative mortality rate between 40% to 60%. Various strategies have been devised to increase the volume and function of future liver remnant (FLR). This study aims to review the strategies used for volume and flow modulation to reduce the incidence of post hepatectomy liver failure.

METHOD

An electronic search was performed of the MEDLINE, EMBASE and PubMed databases from 2000 to 2022 using the following search strategy "Post hepatectomy liver failure", "flow modulation", "small for size flow syndrome", "portal vein embolization", "dual vein embolization", "ALPPS" and "staged hepatectomy" to identify all articles published relating to this topic.

RESULTS

Volume and flow modulation strategies have evolved over time to maximize the volume and function of FLR to mitigate the risk of PHLF. Portal vein with or without hepatic vein embolization/ligation, ALPPS, and staged hepatectomy have resulted in significant hypertrophy and kinetic growth of FLR. Similarly, techniques including portal flow diversion, splenic artery ligation, splenectomy and pharmacological agents like somatostatin and terlipressin are employed to reduce the risk of small for size flow syndrome SFSF syndrome by decreasing portal venous flow and increasing hepatic artery flow at the same time.

CONCLUSION

The current review outlines the various strategies of volume and flow modulation that can be used in isolation or combination in the management of patients at risk of PHLF.

Liver transplantation with simultaneous splenectomy increases risk of cancer development and mortality in hepatocellular carcinoma patients

BACKGROUND

Splenectomy has previously been found to increase the risk of cancer development, including lung, non-melanoma skin cancer, leukemia, lymphoma, Hodgkin’s lymphoma, and ovarian cancer. The risk of cancer development in liver transplantation (LT) with simultaneous splenectomy remains unclear.

AIM

To compare hepatocellular carcinoma (HCC) recurrence and de novo malignancy between patients undergoing LT with and without simultaneous splenectomy.

METHODS

We retrospectively analyzed the outcomes of 120 patients with HCC within the University of California San Francisco criteria who received LT with (n = 35) and without (n = 85) simultaneous splenectomy in the Tri-Service General Hospital. Univariate and multivariate Cox regression analyses for cancer-free survival and mortality were established. The comparison of the group survival status and group cancer-free status was done by generating Kaplan–Meier survival curves and log-rank tests.

RESULTS

The splenectomy group had more hepatitis C virus infection, lower platelet count, higher -fetoprotein level, and longer operating time. Splenectomy and age were both positive independent factors for prediction of cancer development [hazard ratio (HR): 2.560 and 1.057, respectively, P < 0.05]. Splenectomy and hypertension were positive independent factors for prediction of mortality. (HR: 2.791 and 2.813 respectively, P < 0.05). The splenectomy group had a significantly worse cancer-free survival (CFS) and overall survival (OS) curve compared to the non-splenectomy group (5-year CFS rates: 53.4% vs 76.5%, P = 0.003; 5-year OS rate: 68.1 vs 89.3, P = 0.002).

CONCLUSION

Our study suggests that simultaneous splenectomy should be avoided as much as possible in HCC patients who have undergone LT.

Can Living Donor Liver Transplantation in the United States Reach Its Potential?

Living donor liver transplantation (LDLT) is a vital tool to address the growing organ shortage in the United States caused by increasing numbers of patients diagnosed with end-stage liver disease. LDLT still only makes up a very small proportion of all liver transplantations performed each year, but there are many innovations taking place in the field that may increase its acceptance among both transplant programs and patients. These innovations include ways to improve access to LDLT, such as through nondirected donation, paired exchange, transplant chains, transplant of ABO-incompatible donors, and transplants in patients with high Model for End-Stage Liver Disease scores. Surgical innovations, such as laparoscopic donor hepatectomy, robotic hepatectomy, and portal flow modulation, are also increasingly being implemented. Policy changes, including decreasing the financial burden associated with LDLT, may make it a more feasible option for a wider range of patients. Lastly, center-level behavior, such as ensuring surgical expertise and providing culturally competent education, will help toward LDLT expansion. Although it is challenging to know which of these innovations will take hold, we are already seeing LDLT numbers improve within the past 2 years.

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

AIM

Little evidence about whether to apply graft-to-recipient body weight ratio (GRWR) or graft weight to standard liver weight (GW/SLW) for graft selection has been published. The aim of the present study was to clarify the importance of the correct use of GRWR and GW/SLW for selecting graft according to the recipients' physique in living donor liver transplantation (LDLT).

METHODS

Data were collected for 694 recipients who underwent LDLT between 1997 and 2020.

RESULTS

One of the marginal grafts meeting GW/SLW ≥ 35% but GRWR < 0.7% has been used in more recipients with men and higher body mass index (BMI), and the other meeting GRWR ≥ 0.7% but GW/SLW < 35% has been used in more recipients with women with lower BMI. In the cohort of BMI > 30 kg/m2, the recipients with GRWR < 0.7% had a significantly higher incidence of small-for-size graft syndrome (SFSS) compared to those with GRWR ≥ 0.7% (P = 0.008, 46.2% vs 5.9%), and using the cutoff of GW/SLW < 35% could not differentiate. In contrast, in the cohort of BMI ≤ 30 kg/m2, the recipients with GW/SLW < 35% also had a significantly higher incidence of SFSS (P = 0.013, 16.9% vs 9.4%). Multivariate analysis showed that GRWR < 0.7% [odds ratio (OR) 14.145, P = 0.048] was the independent risk factor for SFSS in obese recipients, and GW/SLW < 35% [OR 2.685, P = 0.002] was the independent risk factor in non-obese recipients.

CONCLUSION

Proper use of the formulas for calculating GRWR and GW/SLW in choosing graft according to recipient BMI is important, not only to meet metabolic demand for avoiding SFSS but also to ameliorate donor shortages.

Current review of machine perfusion in liver transplantation from the Japanese perspective

In light of the present evidence, machine perfusion is opening up new horizons in the field of liver transplantation. Although many advances have been made in liver transplantation, organ preservation methods have so far changed very little. Static cold storage is universally used for graft preservation in liver transplantation; however, there is a need for better preservation methods, such as ex vivo machine perfusion, to improve the outcomes by decreasing warm ischemic damage. Based on the findings of basic and clinical trials, hypothermic and normothermic machine perfusion techniques are now commercially available and include the OrganOx metra, Liver Assist, Cleveland NMP device, Organ Care System, and LifePort Liver. Recent clinical trials have provided further evidence for the potential role of normothermic machine perfusion to resuscitate and subsequently improve utilization of marginal or currently discarded livers. Further studies are required to explore the longer-term outcomes, late biliary complications, outcomes in specific high-risk groups, viability biomarkers, optimum and maximum perfusion duration, perfusate composition, and liver-directed therapeutic interventions during normothermic machine perfusion. The use of organs from marginal donors after brain death, such as fatty livers and the livers from elderly donors with multiple comorbidities, may be accepted for machine perfusion in Japan in the near future.

The efficacy of intraoperative indocyanine green fluorescence angiography in gastric cancer operation after living donor liver transplantation: A case report

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De novo gastric cancer after living donor liver transplantation.

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Distal gastrectomy after splenectomy.

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ICG is useful for evaluating the blood flow in gastrectomy after LDLT with splenectomy.

Introduction

The incidence of de novo malignancies after organ transplantation is increasing. We herein report a patient who developed gastric cancer after living donor liver transplantation (LDLT) and splenectomy. Intraoperative indocyanine green (ICG) fluorescence angiography immediately after gastrectomy was useful for evaluating the blood supply into the remnant stomach in this patient.

Presentation of case

A 69-year-old woman underwent LDLT and splenectomy for end-stage liver disease. Gastric cancer was found by an endoscopic examination eight years after LDLT. Although total gastrectomy was considered due to previous splenectomy, we decided to intraoperatively evaluate the flow of the remnant stomach using ICG fluorescence. After ligation of the left gastric artery and transection of the stomach with a sufficient proximal margin from the tumor, intraoperative ICG fluorescence angiography showed abundant intramural blood flow of the remnant stomach. We were able to preserve the proximal stomach with confidence and she recovered smoothly after the operation without any signs of acute rejection.

Conclusion

Intraoperative ICG fluorescence angiography may be helpful for evaluating the blood flow in the remnant stomach during surgery for de novo gastric cancer after LDLT.

Post-transplant inflow modulation for early allograft dysfunction after living donor liver transplantation

Background

To treat small-for-size syndrome (SFSS) after living donor liver transplantation (LDLT), many procedures were described for portal flow modulation before, during, or after transplantation. The selection of the procedure as well as the best timing remains controversial.

Case presentation

A 43-year-old female with end-stage liver disease underwent LDLT with extended left with caudate lobe graft from her donor who was her 41-year-old brother (graft volume/standard liver volume (GV/SLV), 35.7%; graft to recipient weight ratio (GRWR), 0.67%). During the surgery, splenectomy could not be performed owing to severe peri-splenic adhesions to avoid the ruined bleedings. The splenic artery ligation was not also completely done because it was dorsal to the pancreas and difficult to be approached. Finally, adequate portal vein (PV) inflow was confirmed after portal venous thrombectomy. As having post-transplant optional procedures that are accessible for PV flow modulation, any other procedures for PV modulation during LDLT were not done until the postoperative assessment of the graft function and PV flow for possible postoperative modulation of the portal flow accordingly. Postoperative PV flow kept as high as 30 cm/s. By the end of the 1st week, there was a progressive deterioration of the total bilirubin profile (peak as 19.4 mg/dL) and ascitic fluid amount exceeded 1000 mL/day. Therefore, splenic artery embolization was done effectively and safely on the 10th postoperative day (POD) to reverse early allograft dysfunction as PV flow significantly decreased to keep within 20 cm/s and serum total bilirubin levels gradually declined with decreased amounts of ascites below 500 mL on POD 11 and thereafter. The patient was discharged on POD 28 with good condition.

Conclusions

SFSS can be prevented or reversed by the portal inflow modulation, even by post-transplant procedure. This case emphasizes that keeping accessible angiographic treatment options for PV modulation, such as splenic artery embolization, after LDLT is quite feasible.

Predictor of outcome after living donor liver transplantation for patients with hepatocellular carcinoma beyond the Japan criteria

BACKGROUND

The Japan criteria (JC, maximum tumor size within 5 cm, within five tumor nodules, AFP within 500 ng/mL or within Milan criteria) have been applied to cadaveric liver transplantation (LT) for hepatocellular carcinoma (HCC) and will be used for living donor LT (LDLT) in Japan. The aim of this study was to verify the JC in LDLT and to clarify the risk factor of HCC recurrence and mortality after LDLT beyond the JC.

PATIENTS AND METHODS

Adult patients who underwent LDLT for end-stage liver disease with HCC until October 2019 were reviewed retrospectively (n = 246). Patients were divided into two groups according to whether they were within JC (n = 203) or beyond JC (n = 43). Recurrence-free or overall survival rates after LDLT were compared. Univariate and multivariate analyses were performed to identify risk factors of HCC recurrence and HCC-related mortality after LDLT for patients beyond the JC.

RESULTS

Patients beyond the JC had significantly poorer 5-year recurrence-free (50.3% vs 95.9%, P < .001) or overall (61.7% vs 98.1%, P < .001) survival rates compared with patients within the JC. A multivariate analysis revealed that des-gamma-carboxy prothrombin (DCP) ≥ 300 mAU/mL (hazard ratio 9.36, 95% CI; 2.41-36.4, P = .001) was an independent risk factor for HCC recurrence and HCC-related mortality (hazard ratio 13.8, 95% CI; 1.92-98.6, P = .01) after LDLT in patients beyond the JC.

CONCLUSION

The outcome of LDLT for patients within the JC was favorable. Patients beyond the JC with DCP ≥ 300 mAU/mL might be contraindicated for LDLT.