The role of adult living donor liver transplantation and recent advances

The von Willebrand Factor Facilitates Model for End-Stage Liver Disease-Independent Risk Stratification on the Waiting List for Liver Transplantation

BACKGROUND AND AIMS

The Model for End-Stage Liver Disease (MELD) is used for clinical decision-making and organ allocation for orthotopic liver transplantation (OLT) and was previously upgraded through inclusion of serum sodium (Na) concentrations (MELD-Na). However, MELD-Na may underestimate complications arising from portal hypertension or infection. The von Willebrand factor (vWF) antigen (vWF-Ag) correlates with portal pressure and seems capable of predicting complications in patients with cirrhosis. Accordingly, this study aimed to evaluate vWF-Ag as an adjunct surrogate marker for risk stratification on the waiting list for OLT.

APPROACH AND RESULTS

Hence, WF-Ag at time of listing was assessed in patients listed for OLT. Clinical characteristics, MELD-Na, and mortality on the waiting list were recorded. Prediction of 3-month waiting-list survival was assessed by receiver operating characteristics and net reclassification improvement. Interestingly, patients dying within 3 months on the waiting list displayed elevated levels of vWF-Ag (P < 0.001). MELD-Na and vWF-Ag were comparable and independent in their predictive potential for 3-month mortality on the waiting list (area under the curve [AUC], vWF-Ag = 0.739; MELD-Na = 0.764). Importantly, a vWF-Ag cutoff at 413% identified patients at risk for death within 3 months of listing with a higher odds ratio (OR) than the previously published cutoff at a MELD-Na of 20 points (vWF-Ag, OR = 10.873, 95% confidence interval [CI], 3.160, 36.084; MELD-Na, OR = 7.594, 95% CI, 2.578, 22.372; P < 0.001, respectively). Ultimately, inclusion of vWF-Ag into the MELD-Na equation significantly improved prediction of 3-month waiting-list mortality (AUC, MELD-Na-vWF = 0.804).

CONCLUSIONS

A single measurement of vWF-Ag at listing for OLT predicts early mortality. Combining vWF-Ag levels with MELD-Na improves risk stratification and may help to prioritize organ allocation to decrease waiting-list mortality.

Ethical dilemmas related to living donor liver transplantation in Asia

Living donor liver transplantation (LDLT) has evolved rapidly in Asia with good outcomes for both donor and recipient. Nonetheless, LDLT remains a highly demanding technique and complex surgery. The potential risks to the donors provide the basis for many of the ethical dilemmas associated with LDLT. The transplant team must have a good knowledge of the principles of bioethics in order to handle these matters. To look after the need, donor's safety and the chance for good recipient outcomes, the principles of respect for the donor's autonomy, beneficence, and non-maleficence should be practiced. In accordance with the concept of equipoise, the risk to the donor must balance the benefit to the recipient. The transplant center should have adequate experience and proven expertise in LDLT. There are concerns regarding the validity of informed consent given by the donor. While donations to non-relative patients may, at first sight, indicate radical altruism, it is important to apply careful scrutiny. Though organ trading is strictly prohibited by the law, there seems to be an inherent risk with directed donations to strangers. Transplant tourism has flourished in some countries in spite of the existence of strict laws. There are reservations regarding transplantation done by foreign visiting teams. Donor websites facilitating patients and donors and Facebook pages bear no responsibility for the outcomes of their matches and cannot ensure sufficient and accurate information about donation, transplantation, and post-operation life. Telemedicine and virtual consultations appeared to work better when the clinician and the patient know and trust each other.

Risk factors and survival outcomes of biliary complications after adult-to-adult living donor liver transplantation

The objective of this study was to evaluate the risk factors and survival outcomes of biliary complications (BCs) after living donor liver transplantation (LDLT) based on our single-center experience. From 2007 to 2010, 112 adult patients were assessed. Forty-nine patients (43.8%) experienced at least one episode of BCs, including biliary stricture and bile leak, occurring in 37.5% and 16.1% of the patients, respectively. Multivariate analysis indicated that hepatic artery thrombosis (relative risk (RR), 5.692; 95% CI, 2.132 to 15.201; p < 0.001), a hepatic duct diameter of less than 3 mm (RR, 2.523; 95% CI, 1.295 to 4.914; p = 0.005), ductoplasty (RR, 2.175; 95% CI, 1.134 to 4.174; p = 0.018), and cytomegalovirus infection (RR, 4.452; 95% CI, 1.868 to 10.613; p = 0.001) were independent risk factors for the development of BCs. However, these factors and BCs showed no prominent impact on the overall survival (OS) and graft survival (GS). In addition, the patients who developed vascular complications demonstrated poor outcomes in terms of OS (five-year, 56.3% vs. 78.1%; p = 0.017), GS (five-year, 56.3% vs. 77.1%; p = 0.023), and BC-free survival (five-year, 25.0% vs. 63.5%; p = 0.007) compared with patients without vascular complications. In conclusion, BCs remain a common problem after LDLT, especially for patients using duct-to-duct anastomosis. Hepatic artery thrombosis, a short duct diameter, ductoplasty, and cytomegalovirus infection lead to an increased incidence of BCs. The occurrence of BCs manifested no significant influence on the long-term survival outcomes. However, our findings await verification through large-scale randomized studies regarding the risk factors for the development of BCs and their impact on the prognosis.

Current status and perspectives in split liver transplantation

Growing experience with the liver splitting technique and favorable results equivalent to those of whole liver transplant have led to wider application of split liver transplantation (SLT) for adult and pediatric recipients in the last decade. Conversely, SLT for two adult recipients remains a challenging surgical procedure and outcomes have yet to improve. Differences in organ shortages together with religious and ethical issues related to cadaveric organ donation have had an impact on the worldwide distribution of SLT. Despite technical refinements and a better understanding of the complex liver anatomy, SLT remains a technically and logistically demanding surgical procedure. This article reviews the surgical and clinical advances in this field of liver transplantation focusing on the role of SLT and the issues that may lead a further expansion of this complex surgical procedure.