A complete treatment of adult living donor liver transplantation: a review of surgical technique and current challenges to expand indication of patients

Predictors of decision ambivalence and the differences between actual living liver donors and potential living liver donors

Background

The decision to become a living liver donor is a stressful event. Ambivalence in decision making may result in psychological distress. Thus, the purpose of this study was to provide a description of the ambivalence of potential living liver donors, to examine the predictors of ambivalence, and to compare the ambivalence of potential living liver donors with that of actual living liver donors.

Methods

This descriptive and correlational study was conducted in a medical center from August 2013 to December 2015. Self-reported questionnaires were used to collect data. A total of 263 potential living liver donors who were assessed for donation to their parents were included in this study.

Results

The mean age of the total sample was 30.7 years (SD = 6.39, range = 20–47), and males comprised 53.6% of the sample. The majority of the potential donors had a college education (70.8%) and were single (63.5%). Of the total sample, the mean score for ambivalence was 4.27 (SD = 1.87, range = 0–7). Multivariate analysis revealed that the Mental Component Summary (MCS) of quality of life (β = -0.24, p < 0.01), family support (β = -0.17, p = 0.007), and intimacy (β = -0.13, p = 0.04) were significant protective predictors of ambivalence. Actual living liver donors had significantly lower ambivalence (3.82 versus 4.60), higher intimacy with recipients (3.55 versus 3.34), higher MCS (45.26 versus 42.80), and higher family support (34.39 versus 29.79) than did the remaining potential living liver donors.

Conclusion

Ambivalence is common in potential living liver donors. The MCS of quality of life, family support, and intimacy were protective predictors in terms of ambivalence. Future research should explore other factors and design interventions targeted toward reducing ambivalence, promoting family support, and enhancing the mental dimensions of quality of life in potential living liver donors.

How to Perform Selective Liver Biopsy in Living Liver Donors Using Plain Computed Tomography

BACKGROUND

Preoperative donor liver biopsy is the criterion standard to verify the quality of a liver. However, it can cause some complications, thus this study was designed to know whether selective liver biopsy is possible or not, and to find a subgroup that does not require preoperative biopsy.

METHODS

We reviewed preoperative images and postoperative outcome in 118 donors from September 2013 to January 2014. Visual grading of steatosis on plain computed tomography (CT) was performed and compared steatosis on preoperative liver biopsy was done within 7 days from the CT scan.

RESULTS

Visual grades of plain CT were 1 (n = 50, 42.4%), 2 (n = 47, 39.8%), 3 (n = 13, 11.0%), 4 (n = 7, 5.9%), and 1 (n = 1, 0.8%). Macrovesicular steatosis on liver biopsy according to visual grades were 1 (0.67 ± 1.3%), 2 (1.67 ± 1.8%), 3 (6.23 ± 6.4%), 4 (14.7 ± 16.6), and 5 (30%). Right liver grafts including right lobe, modified right lobe, and extended right lobe were procured in 106 (89.9%) donors, and 16% (17/106) of the donors were visual grades 3, 4, and 5. Eleven donors (64.7%) were accepted for right liver donation after liver biopsy, whereas 6 (35.3%) donors were deemed possible to donate right liver after weight reduction and reevaluation of steatosis. Transient hepatic dysfunction after right hepatectomy was significantly increased according to the increment of visual grade.

CONCLUSIONS

Preoperative liver biopsy may not be necessary in visual grade 1 or 2 donors, but should be performed for grade 3 and 4 donors based on recipient's urgency so as to decide whether to proceed with right hepatectomy or not.

Surgical issues in retrieval and implantation

With increasing demand for organ transplantation and patients deteriorating or dying on the waiting list, organs are now being increasingly used from donors previously considered too marginal. This requires improvements to donor management during the retrieval process, and of the organ during transport and subsequent implantation, in order to maintain outcomes.

Portosystemic collaterals in living donor liver transplantation: What is all the fuss about?

Portosystemic collaterals are a common finding in patients with cirrhosis undergoing liver transplantation. Recently, there has been a renewed interest regarding their significance in the setting of living donor liver transplantation (LDLT) due to concerns of graft hypoperfusion or hyperperfusion and its impact on early posttransplant outcomes. Presence of these collaterals has greater significance in the LDLT setting when compared with the deceased donor liver transplantation setting as dictated by the difference in the physiology of partial liver grafts. We discuss current thinking of portal flow dynamics and the techniques for dealing with this clinical problem. Liver Transplantation 23 537-544 2017 AASLD.

Liver transplantation for hepatocellular carcinoma: outcomes and novel surgical approaches

Liver transplantation for hepatocellular carcinoma (HCC) is the best treatment option for patients with early-stage tumours and accounts for ∼20-40% of all liver transplantations performed at most centres worldwide. The Milan criteria are the most common criteria to select patients with HCC for transplantation but they can be seen as too restrictive. Several proposals have been made for a moderate expansion of the criteria, which result in good outcomes but with an increase in the risk of tumour recurrence. In this Review, we provide a comprehensive overview of the outcomes after liver transplantation for HCC, focusing on tumour recurrence in terms of surveillance, prevention and treatment. Additionally, novel surgical techniques have been developed to increase the available pool of organs for liver transplantation (such as living donor liver transplantation, donation after circulatory death and split livers), but the effect of these techniques on patients with HCC is still under debate. Thus, we will describe these techniques and expose the benefits and disadvantages of each surgical approach. Finally, we will comment on the limitations of the current priority policies for liver transplantation and the need to further refine them to better serve the population.

Small-for-Size Syndrome: Bridging the Gap Between Liver Transplantation and Graft Recovery

In living donor liver transplantation, optimal graft size is estimated from values like graft volume/standard liver volume and graft/recipient body weight ratio but the final functional hepatic mass is influenced by other donor and recipient factors. Grafts with insufficient functional hepatic mass can produce a life-threatening condition with rapidly progressive liver failure called small-for-size syndrome (SFSS). Diagnosis of SFSS requires careful surveillance for signs of inadequate hepatocellular function, residual portal hypertension, and systemic inflammation that suggest rapidly progressive liver failure. Early diagnosis, symptom control, and addressing the cause of SFSS may prevent the need for retransplantation. With increased attention to avoiding donor risk, intensivists will be confronted with more SFSS recipients. In this review, we aim to outline a systematic approach to the medical management of patients with SFSS by providing a concise synopsis of general supportive care—neurological, cardiovascular, and renal support, mechanical ventilation, nutritional support, infection control, and tailored immunosuppression—with an aim to avoid end-organ damage or death and a review of current interventions including liver support devices, portal flow modulating drugs, and other experimental interventions that aim to preserve existing hepatic mass and improve conditions for hepatic regeneration. We examine evidence for SFSS interventions to provide the reader with information that may assist in clinical decision making. Points of controversy in care are purposefully highlighted to identify areas where additional experimental work is still needed. A full understanding of the pathophysiology of SFSS and measures to support liver regeneration will guide effective management.

Liver Transplantation After Transarterial Chemoembolization and Radiotherapy for Hepatocellular Carcinoma with Vascular Invasion

PURPOSE

The study aims to analyze the oncologic outcomes of living donor liver transplantation (LDLT) after combined transarterial chemoembolization (TACE) and radiotherapy for hepatocellular carcinoma (HCC) with major vascular invasion.

METHODS

We retrospectively reviewed 17 HCC patients with major vascular invasion who underwent LDLT after combined treatment modality between May 2007 and September 2014. The LDLT timing was determined by the surgeons depending on the disease status and liver function. The intrahepatic recurrence-free survival, disease-free survival (DFS), and overall survival (OS) rates were estimated from the date of the LDLT.

RESULTS

The median follow-up period was 24.5 months (range, 6.4-66.0 months) after the LDLT. The interval between the combined treatment and the LDLT was a median of 5 months (range, 0.4-65.3 months). On the explanted liver, total necrosis was shown in five patients (29.4 %). The 1- and 3-year DFS rates were 70.6 and 57.8 %, respectively. The 1- and 3-year OS rates were 87.4 and 60.5 %, respectively. The major pattern of failure was distant metastasis (35.3 %), and intrahepatic recurrence occurred in three patients (17.6 %) who experienced distant metastasis.

CONCLUSIONS

In the selected HCC patients with major vascular invasion, LDLT after combined TACE and radiotherapy showed acceptable oncologic outcomes.

Small-for-size syndrome in live donor liver transplantation-Pathways of injury and therapeutic strategies

Due to the severe organ shortage and the increasing gap between the supply and demand for donor grafts, live donor liver transplantation (LDLT) has become an accepted and alternative technique for the expansion of the donor pool. However, donor safety and good recipient outcomes must be balanced regarding risk stratification and decision-making within this patient population. Small-for-size syndrome (SFSS) is one of the complications encountered after LDLT, thus increasing the burden of optimizing donor graft selection and effective treatments during its occurrence. A graft-to-recipient weight ratio (GRWR) <0.8 predisposes the graft to SFSS. However, other factors may induce this complication even without a graft-to-patient size mismatch. Several strategies to prevent this complication include portal vein flow and liver outflow modulation, as well as pharmacological treatment. Also, as an entity with a multifactorial etiology, outcomes vary between right-lobe, left-lobe, and posterior-lobe donation among series encountered in the literature. In this review, we analyze the pathophysiology and classification of this complication, the state-of-the-art on management of SFSS, and the outcomes regarding the best treatment strategy on this patient population.

Risk factors for intraoperative massive transfusion in pediatric liver transplantation: a multivariate analysis

Background: Pediatric liver transplantation (LT) is strongly associated with increased intraoperative blood transfusion requirement and postoperative morbidity and mortality. In the present study, we aimed to assess the risk factors associated with massive transfusion in pediatric LT, and examined the effect of massive transfusion on the postoperative outcomes. Methods: We enrolled pediatric patients who underwent LT between December 1994 and June 2015. Massive transfusion was defined as the administration of red blood cells ≥100% of the total blood volume during LT. The cases of pediatric LT were assigned to the massive transfusion or no-massive transfusion (administration of red blood cells <100% of the total blood volume during LT) group. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors associated with massive transfusion in pediatric LT. Kaplan-Meier survival analysis, with the log rank test, was used to compare graft and patient survival within 6 months after pediatric LT between the 2 groups. Results: The total number of LT was 112 (45.0%) and 137 (55.0%) in the no-massive transfusion and massive transfusion groups, respectively. Multivariate logistic regression analysis indicated that high white blood cell (WBC) count, low platelet count, and cadaveric donors were significant predictive factors of massive transfusion during pediatric LT. The graft failure rate within 6 months in the massive transfusion group tended to be higher than that in the no-massive transfusion group (6.6% vs. 1.8%, P = 0.068). However, the patient mortality rate within 6 months did not differ significantly between the massive transfusion and no-massive transfusion groups (7.3% vs. 7.1%, P = 0.964). Conclusion: Massive transfusion during pediatric LT is significantly associated with a high WBC count, low platelet count, and cadaveric donor. This finding can provide a better understanding of perioperative blood transfusion management in pediatric LT recipients.

Living donor liver transplantation in patients weighing ≥100 kg: Low graft weight and obesity do not impact outcomes

Living donor liver transplantation (LDLT) in obese patients raises concerns with regards to obtaining grafts of "adequate" graft-to-recipient weight ratio (GRWR) and the impact of obesity on the outcomes of LDLT. LDLT outcomes in patients weighing ≥100 kg were compared with those weighing <100 kg. Patients weighing ≥100 kg were divided into 3 categories based on the GRWR of the grafts they received. Groups 1, 2, and 3 included patients with GRWR ≥0.8%, between 0.65% and 0.8%, and <0.65%, respectively. The 56 (6.5%) adult liver transplants were performed in patients weighing 100 kg or more. Except for higher mean body mass index (35.8 versus 25.2 kg/m² ; P value < 0.01) and grafts of lower GRWR in obese patients (0.74% versus 1.02%; P value < 0.01), all other parameters were similar between the 2 groups. Despite obesity and smaller grafts, the posttransplant outcomes such as day to normal bilirubin and international normalized ratio; infective, respiratory, and biliary complications; and hospital mortality were similar between the 2 groups. On comparing obese patients in the 3 GRWR categories, except for graft weight (985 versus 769 versus 646 g; P value < 0.01), all the pretransplant parameters were comparable. There was no significant difference in terms of graft function, postoperative morbidity, and hospital mortality between patients with grafts of normal GRWR and those with grafts of low and very low GRWR. Grafts of low GRWR give satisfactory results in obese patients undergoing LDLT and obesity does not adversely impact the outcome of LDLT. Liver Transplantation 23:35-42 2017 AASLD.

Comparison of acute kidney injury between ABO-compatible and ABO-incompatible living donor liver transplantation: A propensity matching analysis

The anti-CD20 monoclonal antibody rituximab has significantly decreased the prevalence of antibody-mediated rejection of ABO-incompatible (ABOi) living donor liver transplantation (LDLT). However, little is known about acute kidney injury (AKI) following ABOi LDLT. The aim of this study was to identify the incidence of AKI in ABOi LDLT and compare it with that of ABO-compatible (ABOc) LDLT. We retrospectively collected and analyzed the data of 1617 patients who underwent liver transplant surgery from November 2008 to December 2014. Risk factors for AKI were investigated using multivariate regression analysis. In 271 ABOi LDLTs, AKI occurred in 184 (67.9%) according to Kidney Disease: Improving Global Outcomes criteria. After propensity score matching, the incidence of AKI was significantly higher after ABOi LDLT than after ABOc LDLT (67.0% versus 48.2%; P < 0.001). Furthermore, the intensive care unit stay (P = 0.01) was significantly prolonged, but there were no significant differences in mortality (P = 0.74), graft failure (P = 0.32), and postoperative dialysis (P = 0.74) between the 2 groups. Hemoglobin level and operation time were independent risk factors for AKI following ABOi LDLT. In conclusion, the incidence of AKI is higher in ABOi LDLT than ABOc LDLT. However, the impact of AKI on postoperative outcomes was not marked in our study. Therefore, ABOi LDLT in selected patients is promising with apparent good graft and survival outcomes. Liver Transplantation 22 1656-1665 2016 AASLD.

ABO-Incompatible Living Donor Liver Transplantation in Focus of Antibody Rebound

BACKGROUND

Living donor liver transplantation (LDLT) is an option to expand the donor organ pool for patients with life-threatening diseases who cannot be supplied with a cadaver organ. Next to the donor risks, complications after ABO-incompatible LDLT (ABOi LDLT) in the recipient are subject to controversial discussion. Improvement in ABOi graft survival rates have been achieved with plasma treatment procedures (PTP) and immunosuppression but antibody-mediated rejection (AMR) and graft loss still occur.

METHODS

Since 2008, we have prepared 10 patients for ABOi LDLT. Seven of the 10 patients for transplantation had hepatocellular carcinoma (HCC).

RESULTS

All patients underwent PTP before and after ABOi LDLT as well as immunosuppression according to the treatment schedule. We did not use anti-CD20 monoclonal antibodies in the transplant setting. We transplanted 6 of 10 preconditioned patients. After 3 years, 5 of the 6 transplanted patients were still alive.

CONCLUSION

Even if B-cell depletion with anti-CD 20 treatment in the setting of ABOi LDLT is commonly accepted, our center successfully administered only quadruple drug immunosuppression combined with PTP. Especially patients with HCC had a high titer increment also pre-transplantation and were at high risk for arterial thrombosis and graft loss.

How much liver needs to be transected in ALPPS? A translational study investigating the concept of less invasiveness

BACKGROUND

ALPPS induces rapid liver hypertrophy after stage-1 operation, enabling safe, extended resections (stage-2) after a short period. Recent studies have suggested that partial transection at stage-1 might be associated with a better safety profile. The aim of this study was to assess the amount of liver parenchyma that needs to be divided to achieve sufficient liver hypertrophy in ALPPS.

METHODS

In a bi-institutional, prospective cohort study, nonfibrotic patients who underwent ALPPS with complete (n = 22) or partial (n = 23) transection for colorectal liver metastases were analyzed and compared with an external ALPPS cohort (n = 23). A radiologic tool was developed to quantify the amount of parenchymal transection. Liver hypertrophy and clinical outcome were compared between both techniques. The relationship of partial transection and hypertrophy was investigated further in an experimental murine model of partial ALPPS.

RESULT

The median amount of parenchymal transection in partial ALPPS was 61% (range, 34-86%). The radiologic method correlated poorly with the intraoperative surgeon's estimation (r_S = 0.258). Liver hypertrophy was equivalent for the partial ALPPS, ALPPS, and external ALPPS cohort (64% vs 60% vs. 64%). Experimental data demonstrated that partial transection of at least 50% induced comparable hypertrophy (137% vs 156%) and hepatocyte proliferation compared to complete transection.

CONCLUSION

The study provides clinical and experimental evidence that partial liver partition of at least 50% seems to be equally effective in triggering volume hypertrophy as observed with complete transection and can be re recommended as less invasive alternative to ALPPS.

Portal vein stenting as a significant risk factor for biliary stricture in adult living donor liver transplantation

BACKGROUND

Although perioperative portal vein (PV) stent implantation is an effective treatment for steno-occlusive disease in adult living donor liver transplantation (LDLT) recipients, we experienced high incidence of biliary anastomotic strictures (BAS) after PV stenting. In this study, we sought to clarify the relation between BAS and PV stenting and to suggest the possible mechanism of BAS and measures to reduce its incidence.

METHODS

We retrospectively analyzed 44 LDLT recipients who underwent PV stent implantation across the line of PV anastomosis regardless of the location of steno-occlusion (stent group) and their matched controls (non-stented LDLT recipients, n=131).

RESULTS

The incidence of BAS was higher in patients in the stent group than that in the control group (43.2% vs 17.6%, P=0.001). Cumulative 6-month and 1-, 2- and 5-year BAS rates were 31.8%, 34.1%, 41.4% and 43.2%, respectively, in the stent group and 13.0%, 13.8%, 16.1% and 17.8%, respectively, in the control group (P=0.001). Multivariate analysis revealed that PV stenting was an independent risk factor for BAS.

CONCLUSIONS

Although PV stent implantation is a reliable treatment modality for steno-occlusive PV in adult LDLT recipients, innovative methods to prevent the PV stent from crossing the line of PV anastomosis may be necessary to reduce the incidence of postoperative BAS.

Current techniques for AB0-incompatible living donor liver transplantation

For a long time, it was considered medical malpractice to neglect the blood group system during transplantation. Because there are far more patients waiting for organs than organs available, a variety of attempts have been made to transplant AB0-incompatible (AB0i) grafts. Improvements in AB0i graft survival rates have been achieved with immunosuppression regimens and plasma treatment procedures. Nevertheless, some grafts are rejected early after AB0i living donor liver transplantation (LDLT) due to antibody mediated rejection or later biliary complications that affect the quality of life. Therefore, the AB0i LDLT is an option only for emergency situations, and it requires careful planning. This review compares the treatment possibilities and their effect on the patients’ graft outcome from 2010 to the present. We compared 11 transplant center regimens and their outcomes. The best improvement, next to plasma treatment procedures, has been reached with the prophylactic use of rituximab more than one week before AB0i LDLT. Unfortunately, no standardized treatment protocols are available. Each center treats its patients with its own scheme. Nevertheless, the transplant results are homogeneous. Due to refined treatment strategies, AB0i LDLT is a feasible option today and almost free of severe complications.

Comprehensive guide to laparoscope-assisted graft harvesting in live donors for living-donor liver transplantation: perspective of laparoscopic vision

Background

A living donor (LD) for liver transplantation (LT) is the best target for minimally invasive surgery. Laparoscope-assisted surgery (LAS) for LDs has gradually evolved. A donor safety rate of 100% should be guaranteed.

Methods

We began performing LAS for LDs in June 2012. The aim of this report is to describe the surgical procedures of LAS in detail, discuss various tips and pitfalls, and address the potential for a smooth transition to more advanced LAS.

Results

Preoperative planning based on three-dimensional image analysis is a powerful tool for successful surgery. The combination of liver retraction/countertraction and the pressure produced by pneumoperitoneum widens the dissectible/cuttable layer, increasing the safety of LAS. A flexible laparoscope provides excellent magnified vision in both the horizontal view along the inferior vena cava, under adequate liver retraction, and in the lateral view, to harvest left-sided grafts in critical procedures. Intentional omission of painful incisions is beneficial for LDs. Hepatectomy using a smaller midline incision is safe if a hanging maneuver is used. Safe transition from LAS to a hybrid technique involving a combination of pure laparoscopic surgery and subsequent open surgery seems possible.

Conclusion

LDLT surgeons have a very broad intellectual and technical frontier.

Split liver transplantation in adults

Split liver transplantation (SLT), while widely accepted in pediatrics, remains underutilized in adults. Advancements in surgical techniques and donor-recipient matching, however, have allowed expansion of SLT from utilization of the right trisegment graft to now include use of the hemiliver graft as well. Despite less favorable outcomes in the early experience, better outcomes have been reported by experienced centers and have further validated the feasibility of SLT. Importantly, more than two decades of experience have identified key requirements for successful SLT in adults. When these requirements are met, SLT can achieve outcomes equivalent to those achieved with other types of liver transplantation for adults. However, substantial challenges, such as surgical techniques, logistics, and ethics, persist as ongoing barriers to further expansion of this highly complex procedure. This review outlines the current state of SLT in adults, focusing on donor and recipient selection based on physiology, surgical techniques, surgical outcomes, and ethical issues.

Percutaneous transhepatic cholangioscopy for biliary complications after liver transplantation: a single center experience

BACKGROUND

Some biliary complications after liver transplantation (LT) are difficult to manage by endoscopic or radiologic intervention alone. In these cases, percutaneous transhepatic cholangioscopy (PTCS) can be used as an adjuvant option.

METHODS

Patients who underwent PTCS for post-LT biliary complications between August 1992 and January 2016 were retrospectively reviewed.

RESULTS

Fifteen patients underwent PTCS for post-LT biliary complications. The median age at LT was 47 years and 11 patients were male. Indications for LT were as follows: decompensated liver cirrhosis (n = 9), hepatocellular carcinoma (n = 5), and acute fulminant liver failure (n = 1). Single living donor was common (n = 11) and duct-to-duct anastomosis was performed in 11 patients. The median age at PTCS was 52 years and indications for PTCS were as follows: intrahepatic duct stone (n = 10), common bile duct stone (n = 1), biliary cast (n = 1), and biliary stricture (n = 3). There were no significant PTCS-related morbidity and mortality. However, four patients (26.7%) needed additional radiologic intervention (n = 2) or surgery (n = 2) after PTCS.

CONCLUSIONS

Percutaneous transhepatic cholangioscopy in conjunction with endoscopic and radiologic interventions can aid in managing post-LT biliary complications and avoiding reoperation.

Donor Safety and Recipient Liver Function After Right-Lobe Liver Transplantation From Living Donors With Gilbert Syndrome

BACKGROUND

Donor safety is the most important aspect in living-donor liver transplantation (LDLT). Gilbert syndrome is an autosomal recessive condition that is a common cause of isolated unconjugated hyperbilirubinemia, and its prevalence is not negligibly low in the general population. This study intended to assess donor safety and recipient liver function after LDLT with the use of right liver grafts from living donors with Gilbert syndrome.

METHODS

Among 2,140 right liver transplantations performed from January 2002 to December 20113 at our institution, we identified 12 living donors (0.6%) who showed a preoperative serum total bilirubin level of ≥2 mg/dL. These donors were clinically diagnosed with Gilbert syndrome. The clinical outcomes of these donors and their recipients were analyzed retrospectively.

RESULTS

The mean donor age was 24.6 ± 7.1 years, and 11 donors were male. All subjects met the preoperative evaluation conditions for right liver donation except for the level of unconjugated hyperbilirubinemia. The mean serum total bilirubin level of the donors was 2.23 ± 0.20 mg/dL before and 1.79 ± 0.61 mg/dL 1 year after right liver donation. The preoperative donor direct bilirubin level was 0.43 ± 0.19 mg/dL. The preoperative indocyanine green retention rate at 15 minutes was 8.2 ± 2.8%. All donors and recipients recovered uneventfully and were alive at the time of writing. The recipient serum total bilirubin level was 1.29 ± 0.47 mg/dL 1 year after LDLT.

CONCLUSIONS

We suggest that LDLT with living donors with Gilbert syndrome can be safely performed, but that a meticulous preoperative evaluation is vital to maximize donor safety.

Liver regeneration - mechanisms and models to clinical application

Liver regeneration has been studied for many decades and the mechanisms underlying regeneration of the normal liver following resection or moderate damage are well described. A large number of factors extrinsic (such as bile acids and circulating growth factors) and intrinsic to the liver interact to initiate and regulate liver regeneration. Less well understood, and more clinically relevant, are the factors at play when the abnormal liver is required to regenerate. Fatty liver disease, chronic scarring, prior chemotherapy and massive liver injury can all inhibit the normal programme of regeneration and can lead to liver failure. Understanding these mechanisms could enable the rational targeting of specific therapies to either reduce the factors inhibiting regeneration or directly stimulate liver regeneration. Although animal models of liver regeneration have been highly instructive, the clinical relevance of some models could be improved to bridge the gap between our in vivo model systems and the clinical situation. Likewise, modern imaging techniques such as spectroscopy will probably improve our understanding of whole-organ metabolism and how this predicts the liver's regenerative capacity. This Review describes briefly the mechanisms underpinning liver regeneration, the models used to study this process, and discusses areas in which failed or compromised liver regeneration is clinically relevant.

Clinical analysis of patients with hepatocellular carcinoma recurrence after living-donor liver transplantation

AIM: To evaluated patterns and outcomes of hepatocellular carcinoma (HCC) recurrence after living donor liver transplantation (LDLT).

METHODS: From 2001 to 2014, 293 patients underwent LDLT for HCC at our transplant center. We retrospectively reviewed 54 (18.4%) patients with HCC recurrence after LDLT. We evaluated patterns and outcomes of HCC recurrence after LDLT, with particular attention to the Milan criteria at transplantation, treatments for HCC-recurrent patients, and factors related to survival after HCC recurrence. Furthermore, we evaluated the efficacy of combination treatment of sorafenib and an mTOR inhibitor.

RESULTS: The 1-, 2-, and 3-year overall survival rates after HCC recurrence were 41.1%, 20.5%, and 15.4%, respectively. The median time interval between LDLT and HCC recurrence was 6.5 mo. Although recurrence rates according to the Milan criteria at LDLT were significantly different, HCC recurrence patterns and survival rates after HCC recurrence were not significantly different between the two groups. Time to recurrence < 12 mo (P = 0.048), multiple recurrences at HCC recurrence (P = 0.038), and palliative treatment for recurrent tumors (P = 0.003) were significant independent prognostic factors for poor survival after HCC recurrence in a multivariate analysis. The combination treatment of sorafenib and sirolimus showed survival benefits in the palliative treatment group (P = 0.005).

CONCLUSION: Curative treatment for recurrent HCC after LDLT is the most important factor in survival rates after HCC recurrence and combination treatments of sorafenib and an mTOR inhibitor could have survival benefits in patients with HCC recurrence after LT in the palliative treatment group.

Extended-criteria donors in liver transplantation Part II: reviewing the impact of extended-criteria donors on the complications and outcomes of liver transplantation

Extended-criteria donors (ECDs) have an impact on early allograft dysfunction (EAD), biliary complications, relapse of hepatitis C virus (HCV), and survivals. Early allograft dysfunction was frequently seen in grafts with moderate and severe steatosis. Donors after cardiac death (DCD) have been associated with higher rates of graft failure and biliary complications compared to donors after brain death. Extended warm ischemia, reperfusion injury and endothelial activation trigger a cascade, leading to microvascular thrombosis, resulting in biliary necrosis, cholangitis, and graft failure. The risk of HCV recurrence increased by donor age, and associated with using moderately and severely steatotic grafts. With the administration of protease inhibitors sustained virological response was achieved in majority of the patients. Donor risk index and EC donor scores (DS) are reported to be useful, to assess the outcome. The 1-year survival rates were 87% and 40% respectively, for donors with a DS of 0 and 3. Graft survival was excellent up to a DS of 2, however a DS >2 should be avoided in higher-risk recipients. The 1, 3 and 5-year survival of DCD recipients was comparable to optimal donors. However ECDs had minor survival means of 85%, 78.6%, and 72.3%. The graft survival of split liver transplantation (SLT) was comparable to that of whole liver orthotopic liver transplantation. SLT was not regarded as an ECD factor in the MELD era any more. Full-right-full-left split liver transplantation has a significant advantage to extend the high quality donor pool. Hypothermic oxygenated machine perfusion can be applied clinically in DCD liver grafts. Feasibility and safety were confirmed. Reperfusion injury was also rare in machine perfused DCD livers.

Atrioventricular conduction disturbances immediately after hepatic graft reperfusion and their outcomes in patients undergoing liver transplantation

Hemodynamic perturbation during hepatic graft reperfusion in patients undergoing liver transplantation (LT) is challenging and is frequently accompanied by bradyarrhythmia and even asystole. However, detailed data on electrocardiographic (ECG) changes during reperfusion are almost nonexistent, although the correct diagnosis by record is important for the treatment. We aimed to identify ECG rhythm disturbances during graft reperfusion and to investigate risk factors and outcomes. Data from 1065 consecutive patients who underwent adult LT were analyzed. The incidence, type, and detailed characteristics of ECG changes immediately after graft reperfusion were assessed using an electronically archived intraoperative ECG database. We analyzed risk factors, postoperative outcomes including major cardiovascular events, 30-day and 1-year mortalities of recipients based on the occurrence of atrioventricular (AV) block, and asystole during reperfusion. The typical pattern of postreperfusion bradyarrhythmia was progressive PR interval prolongation until a Mobitz type 1 AV block occurred. The overall incidence of AV block was 5.0% (53/1065), and 30.2% of them (16/53) had initiated as AV block and then progressed into ventricular asystole. Fulminant hepatic failure was a significant predictor for occurrence of AV block (odds ratio [OR], 7.20; 95% confidence interval, 3.38-15.32; P < 0.001). Patients with AV block showed significantly higher incidence of postoperative major cardiovascular events (P < 0.001) and 30-day mortality (P = 0.002) than those without AV block, whereas the 1-year mortality was not different between the 2 groups (P = 0.10). The postreperfusion asystole was consistently preceded by a Mobitz type 1 AV block. The occurrence of AV block and asystole appears to be an important prognosticator. Therefore, maintaining an optimal range of physiological status and gradual unclamping of the vena cava to avoid sudden atrial distension are recommended in high-risk patients during reperfusion period. Liver Transplantation 22 956-967 2016 AASLD.

Impact of Graft Selection on Donor and Recipient Outcomes After Living Donor Liver Transplantation

BACKGROUND

Balancing donor and recipient risks in living donor liver transplantation remains an issue of debate. This study assessed the impact of graft selection on outcomes and complications for left lobe (LL) versus right lobe (RL) donors and recipients.

METHODS

The medical records of donors and recipients, who underwent living donor liver transplantation at our institution between 2003 and 2015, were reviewed. For donors, we evaluated graft volume, residual liver volume per standard liver volume, length of hospital stay (LOS), complications, and readmissions. For recipients, we looked at graft and patient survival, graft function at postoperative days 7 and 14, graft volume, LOS, biliary complications, Model for End-Stage Liver Disease at transplant, and hepatitis C virus status.

RESULTS

At 5 years posttransplant, there were no significant differences in graft survival for LL recipients (86% [95% confidence interval, 74-93]) compared with 82% (95% confidence interval, 69-89) for RL recipients (P = 0.85) or recipient survival (90% vs 84%; P = 0.44). In LL recipients, postoperative days 7 and 14 median international normalized ratio (1.5 and 1.2, respectively) and total bilirubin (4.6 and 2.7) were significantly greater compared with RL recipients (7 and 14 days international normalized ratio [1.2, P < 0.001; 1.1, P = 0.001] and total bilirubin (2.7, P = 0.001; 2.1, P = 0.05)). The LL recipients also had a significantly greater median LOS (14 vs 10, P = 0.008). Median donor LOS was significantly greater for RL donors (7 [interquartile range, 7-8] vs 7 [interquartile range, 6-7] days, P < 0.001).

CONCLUSIONS

The RL and LL grafts provide comparable long-term outcomes in properly selected donor-recipient pairs and the appropriate use of LL grafts does not impact graft or patient survival at 5 years posttransplant.

Selection and Postoperative Care of the Living Donor

Live organ donors typically consult their primary care providers when considering live donation and then return for follow-up after surgery and for ongoing primary care. Live liver and kidney transplants are performed routinely as a method to shorten the waiting time for a recipient, provide a healthy organ for transplant, and increase recipient survival. Careful medical and psychosocial evaluation of the potential donor is imperative to minimize harm. This evaluation must be performed by an experienced live donor medical team. Routine health care with careful attention to weight maintenance, cardiovascular health, and prevention of diabetes and hypertension is paramount.

A review of current status of living donor liver transplantation

Living donor liver transplantation (LDLT) has become an inevitable procedure in Asia due to its shortage of deceased donor under the influence of the religion and native cultures. Through a broad variety of experience, LDLT has been evolved and extended its indication. Although there have been many surgical and ethical efforts to prevent donor risk, concerns of donor's safety still are remaining questions due to its strict selection criteria. Therefore, dual grafts LDLT or ABO incompatible (ABO-I) LDLT may be effective means in its application and safety aspect. Many Asian LDLT centers have pointed out the useful extended criteria of LDLT for hepatocellular carcinoma (HCC), but the applicability of extended criteria should be validated and standardized by worldwide prospective studies based on the Milan criteria. Recent struggling efforts have been reported to surmount extensive portal vein thrombosis and Budd-Chiari syndrome which were previously contraindicated to LDLT. There is no doubt that LDLT is a surely complicated therapy to be performed successfully and requires devoted efforts by surgeons and co-workers. Nonetheless, comprehensive increasing understandings of partial graft LT and improvements of surgical techniques with challenges to obstacles in LDLT will make its prosperity with satisfactory outcomes.

The evolution of anterior sector venous drainage in right lobe living donor liver transplantation: does one technique fit all?

In living donor liver transplantation (LDLT), an adequate hepatic venous outflow constitutes one of the basic principles of a technically successful procedure. The issue of whether the anterior sector (AS) of the right lobe (RL) graft should or should not be routinely drained has been controversial. The aim of this 10-year, single-center, retrospective cohort study was to review the evolution of our hepatic venous outflow reconstruction technique in RL grafts and evaluate the impact of routine AS drainage strategy on the outcome. The study group consisted of 582 primary RL LDLT performed between July 2004 and December 2014. The cases were divided into 3 consecutive periods with different AS venous outflow reconstruction techniques, which included middle hepatic vein (MHV) drainage in Era 1 (n=119), a more selective AS drainage with cryopreserved homologous grafts in Era 2 (n=391), and routine segment 5 and/or 8 oriented AS drainage with synthetic grafts in Era 3 (n=72). Intraoperative portal flow measurement with routine splenic artery ligation (SAL) technique (in RL grafts with a portal flow of ≥ 250 mL/min/100 g liver tissue) was added later in Era 3. These 3 groups were compared in terms of recipient and donor demographics, surgical characteristics and short-term outcome. The rate of AS venous drainage varied from 58.8% in Era 1 and 35.0% in Era 2 to 73.6% in Era 3 (P<0.001). Perioperative mortality rate of recipients significantly decreased over the years (15.1% in Era 1 and 8.7% in Era 2 vs. 2.8% in Era 3, P=0.01). After the addition of SAL technique in the 45 cases, there was only 1 graft loss and no perioperative mortality. One-year recipient survival rate was also significantly higher in Era 3 (79.6% in Era 1 and 86.1% in Era 2 vs. 92.1% in Era 3, P=0.002). Routine AS drainage via segment 5 and/or 8 veins using synthetic grafts is a technique to fit all RL grafts in LDLT. Addition of SAL effectively prevents early graft dysfunction and significantly improves the outcome.

Right lobe living-donor hepatectomy-the Toronto approach, tips and tricks

Living-donor liver transplantation (LDLT) is a well-established treatment for end-stage liver disease. Nevertheless, it has not been extensively accepted in North America or Europe as it has been in Asia. At the University of Toronto we initiated our LDLT program in 2000 and since then our program has grown each year, representing today the largest LDLT program in North America. Our right-lobe LDLT experience from 2000-2014 includes 474 right lobes. Only 30% of our grafts have included the middle hepatic vein. We present excellent outcomes in terms of graft and patient survival which is not different to that achieved with deceased donor liver transplantation. In the present study we will discuss the evolution, challenges and current practices of our LDLT program. We will discuss what is and has been the program philosophy. We will also discuss how we evaluate our donors and the extensive workup we do before a donor is accepted for live donation. Furthermore we will discuss some tips and tricks of how we perform the right hepatectomy for live donation.

[Living liver donor: indications and technical aspects]

Living donor liver transplantation (LDLT) nowadays represents an important and safe alternative to conventional deceased donor liver transplantation (DDLT). A major concern related to the LDLT procedure is still represented by donor safety because a serious operation not without risks must be carried out on a healthy individual. In the present review of the indications for LDLT the technical concepts of donor surgery, criteria for donor selection and evaluation and morbidity and mortality results related to the procedure are presented. In general, the indications for LDLT are almost the same as for DDLT. The donor hepatectomy (right, left or left lateral) is presented in five main phases. The reported morbidity rates vary between 10 % and 60 % and are strongly related to the experience of the transplant center. The currently reported postoperative mortality rates for left and right hepatectomy are 0.1 % and 0.5 %, respectively. The results of LDLT are similar if not even better than those for DDLT depending on the specific indications.

Serial changes of cytokines and growth factors in peripheral circulation after right lobe donor hepatectomy

Cytokines and growth factors have prominent roles in liver regeneration. The aim of this study was to evaluate the biological markers of liver regeneration in healthy donors undergoing right lobe donor hepatectomy for living donor liver transplantation. Twenty-five voluntary liver donors were enrolled. Peripheral blood samples were taken a day before the operation and on postoperative days (PODs) 1, 3, 7, 14, and 42. Levels of hepatocyte growth factor (HGF), interleukin (IL) 6, tumor necrosis factor α (TNF-α), thrombopoietin (TPO), transforming growth factor β1 (TGF-β1), interferon (IFN) α, and IFNγ were monitored. The remnant liver volume (RLV) before surgery and regeneration liver volume (RgV) on POD 14 were calculated on computed tomography (CT). RgV/RLV ratio was correlated with the remnant-liver-volume-to-body-weight ratio (RLVBWR). Inverse correlation was observed between RgV/RLV and RLVBWR (r(2) = 0.61; P < 0.001). There was a significant rise of HGF on POD 1 (P = 0.001), POD 7 (P = 0.049), and POD 14 (P = 0.04). TNF-α was elevated on POD 1 (P = 0.004). The levels of IL 6 (P < 0.001) and TPO (P < 0.001) were higher from POD 1 to POD 42. IFNα was higher on POD 14 (P = 0.003) and POD 42 (P = 0.001). There was a significant fall of IFNγ on POD 1 (P = 0.01) and increase on POD 14 (P = 0.04). The levels of TGF-β1 were higher on POD 14 (P = 0.008) and on POD 42 (P = 0.002). In conclusion, HGF, IL 6, TNF-α, and TPO are involved in the early phase, whereas TGF-β1 and IFN are involved in the termination phase of liver regeneration. Liver regeneration was observed to be higher in donors with low RLVBWR.

Intraoperative factors associated with delayed recovery of liver function after hepatectomy: analysis of 1969 living donors

BACKGROUND

The safety of healthy living donors who are undergoing hepatic resection is a primary concern. We aimed to identify intraoperative anaesthetic and surgical factors associated with delayed recovery of liver function after hepatectomy in living donors.

METHODS

We retrospectively analysed 1969 living donors who underwent hepatectomy for living donor liver transplantation. Delayed recovery of hepatic function was defined by increases in international normalised ratio of prothrombin time and concomitant hyperbilirubinaemia on or after post-operative day 5. Univariate and multivariate logistic regression analyses were performed to determine the factors associated with delayed recovery of hepatic function after living donor hepatectomy.

RESULTS

Delayed recovery of liver function after donor hepatectomy was observed in 213 (10.8%) donors. Univariate logistic regression analysis showed that sevoflurane anaesthesia, synthetic colloid, donor age, body mass index, fatty change and remnant liver volume were significant factors for prediction of delayed recovery of hepatic function. Multivariate logistic regression analysis showed that independent factors significantly associated with delayed recovery of liver function after donor hepatectomy were sevoflurane anaesthesia (odds ratio = 3.514, P < 0.001), synthetic colloid (odds ratio = 1.045, P = 0.033), donor age (odds ratio = 0.970, P = 0.003), female gender (odds ratio = 1.512, P = 0.014) and remnant liver volume (odds ratio = 0.963, P < 0.001).

CONCLUSIONS

Anaesthesia with sevoflurane was an independent factor in predicting delayed recovery of hepatic function after donor hepatectomy. Although synthetic colloid may be associated with delayed recovery of hepatic function after donor hepatectomy, further study is required. These results can provide useful information on perioperative management of living liver donors.

Venous outflow reconstruction in living donor liver transplantation: Dealing with venous anomalies

The reconstruction of the vascular outflow tract of partial liver grafts has received considerable attention in the past, especially in the setting of right liver grafts with undrained segments. Hepatic venous outflow reconstruction is an important factor for successful living donor liver transplantation outcome. However, in presence of undrained anterior sector and presence of multiple short hepatic veins that drain substantial portions of liver, outflow reconstruction without backtable venoplasty may lead to severe graft congestion and subsequent graft dysfunction. Various backtable venoplasty techniques in presence of multiple hepatic veins that can be used in either right- or left-lobe liver transplantation are devised to ensure a single, wide outflow channel. In this overview, various techniques to overcome the hepatic venous variations of liver allograft and outflow reconstruction are discussed.

Fluid management in living donor hepatectomy: Recent issues and perspectives

The importance of the safety of healthy living liver donors is widely recognized during donor hepatectomy which is associated with blood loss, transfusion, and subsequent post-operative morbidity. Although the low central venous pressure (CVP) technique can still be effective, it may not be advantageous concerning the safety of healthy donors undergoing hepatectomy. Emerging evidence suggests that stroke volume variation (SVV), a simple and useful index for fluid responsiveness and preload status in various clinical situations, can be applied as a guide for fluid management to reduce blood loss during living donor hepatectomy. Synthetic colloid solutions are also associated with serious adverse events such as the use of renal replacement therapy and transfusion in critically ill or septic patients. However, it is uncertain whether the intra-operative use of colloid solution is associated with similarly adverse effects in patients undergoing living donor hepatectomy. In this review article we discuss the recent issues regarding the low CVP technique and the high SVV method, i.e., maintaining 10%-20% of SVV, for fluid management in order to reduce blood loss during living donor hepatectomy. In addition, we briefly discuss the effects of intra-operative colloid or crystalloid administration for surgical rather than septic or critically ill patients.

Living donor liver transplantation using dual grafts: Experience and lessons learned from cases worldwide

In living donor liver transplantation (LDLT), insufficient graft volume could result in small-for-size syndrome in recipients, whereas major liver donation predisposes the donor to a high risk of posthepatectomy liver failure. Dual graft LDLT is therefore introduced to obtain combined graft sufficiency. To date, 367 patients have been reported worldwide. We reviewed all the relevant literature, with a special focus on 43 case reports containing enough data to extract and analyze. A simple decision-making algorithm was developed. Dual graft LDLT is indicated when (1) a single donation is unacceptable due to graft-to-recipient size mismatch; (2) the future liver remnant is insufficient in the single donor after major resection; or (3) there is a significant underlying disorder or anatomical variation within the donor liver. The outcome of dual graft LDLT is reported to be comparable with that of single donor LDLT. Unilateral graft atrophy was found in 7 of the 43 patients, predominantly in the right-sided, heterotopic and initially smaller grafts. Technically, the heterotopic implantation and complex vascular reconstruction are the most demanding. Elaborate surgical planning and modification are needed. Ethical concerns about involving a second living donor need to be addressed. In conclusion, dual graft LDLT should be prudently performed in select cases by surgeons of proven expertise when single donation is unacceptable and a second living donor is available. The decision-making criteria need to be standardized. More surgical modification and clinical research are needed.

Defining long-term outcomes with living donor liver transplantation in North America

OBJECTIVES

To compare long-term survival of living donor liver transplant (LDLT) at experienced transplant centers with outcomes of deceased donor liver transplant and identify key variables impacting patient and graft survival.

BACKGROUND

The Adult-to-Adult Living Donor Liver Transplantation Cohort Study is a prospective multicenter National Institutes of Health study comparing outcomes of LDLT and deceased donor liver transplant and associated risks.

METHODS

Mortality and graft failure for 1427 liver recipients (963 LDLT) enrolled in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study who received transplant between January 1, 1998, and January 31, 2014, at 12 North American centers with median follow-up 6.7 years were analyzed using Kaplan-Meier and multivariable Cox models.

RESULTS

Survival probability at 10 years was 70% for LDLT and 64% for deceased donor liver transplant. Unadjusted survival was higher with LDLT (hazard ratio = 0.76, P = 0.02) but attenuated after adjustment (hazard ratio = 0.98, P = 0.90) as LDLT recipients had lower mean model for end-stage liver disease (15.5 vs 20.4) and fewer received transplant from intensive care unit, were inpatient, on dialysis, were ventilated, or with ascites. Posttransplant intensive care unit days were less for LDLT recipients. For all recipients, female sex and primary sclerosing cholangitis were associated with improved survival, whereas dialysis and older recipient/donor age were associated with worse survival. Higher model for end-stage liver disease score was associated with increased graft failure. Era of transplantation and type of donated lobe did not impact survival in LDLT.

CONCLUSIONS

LDLT provides significant long-term transplant benefit, resulting in transplantation at a lower model for end-stage liver disease score, decreased death on waitlist, and excellent posttransplant outcomes. Recipient diagnosis, disease severity, renal failure, and ages of recipient and donor should be considered in decision making regarding timing of transplant and donor options.Clinical Trials ID: NCT00096733.

Management of the middle hepatic vein in right lobe living donor liver transplantation: A meta-analysis

Living donor liver transplantation (LDLT) is a curative treatment for end stage liver disease. It is advantageous due to the shortage of deceased donors. However, in LDLT, whether the middle hepatic vein (MHV) should be preserved in donors remains controversial. We conducted searches in Pubmed, Embase, Cochrane Library, Web of Science, Ovid, and Google Scholar using the key words "living donor liver transplantation" and "middle hepatic vein". Due to ethical issues, there were no randomized control trails focusing on MHV in LDLT. The majority of reports were retrospective studies. We examined the reference lists to identify related investigations. Google Scholar was then used to obtain full texts. Nine observational studies were analyzed. There were no significant differences in liver function (WMD, -5.51; P=0.12) and complications (RR, 0.98; P=0.89) in donors with or without MHV. However, the liver function in recipients was greatly improved after LDLT with MHV (WMD, -78.32; P=0.01). No definite conclusion was obtained in terms of the liver regeneration indices between LDLT with or without MHV. It was conclude that grafts with MHV in LDLT favor recipient outcomes and do not harm the living donor if a careful preoperative evaluation is performed.