Prevalence, management and efficacy of treatment in portal vein obstruction after paediatric liver transplantation: protocol of the retrospective international multicentre PORTAL registry.

INTRODUCTION: Portal vein obstruction (PVO) consists of anastomotic stenosis and thrombosis, which occurs due to a progression of the former. The aim of this large-scale international study is to assess the prevalence, current management practices and efficacy of treatment in patients with PVO. METHODS AND ANALYSIS: The Portal vein Obstruction Revascularisation Therapy After Liver transplantation registry will facilitate an international, retrospective, multicentre, observational study, with 25 centres around the world already actively involved. Paediatric patients (aged <18 years) with a diagnosed PVO between 1 January 2001 and 1 January 2021 after liver transplantation will be eligible for inclusion. The primary endpoints are the prevalence of PVO, primary and secondary patency after PVO intervention and current management practices. Secondary endpoints are patient and graft survival, severe complications of PVO and technical success of revascularisation techniques. ETHICS AND DISSEMINATION: Medical Ethics Review Board of the University Medical Center Groningen has approved the study (METc 2021/072). The results of this study will be disseminated via peer-reviewed publications and scientific presentations at national and international conferences. TRIAL REGISTRATION NUMBER: Netherlands Trial Register (NL9261).

Assessment of hepatic artery anatomy in pediatric liver transplant recipients: MR angiography versus CT angiography.

During LT screening, children undergo CTA to determine hepatic artery anatomy. However, CTA imparts radiation, unlike MRA. The aim was to compare MRA to CTA in assessing hepatic artery anatomy in pediatric LT recipients. Twenty-one children (median age 8.9 years) who underwent both CTA and fl3D-ce MRA before LT were retrospectively included. Interreader variability between 2 radiologists, image quality, movement artifacts, and confidence scores, were used to compare MRA to CTA. Subgroup analyses for ages <6 years and ≥6 years were performed. Interreader variability for MRA and CTA in children <6 years was comparable (k = 0.839 and k = 0.757, respectively), while in children ≥6 years CTA was superior to MRA (k 1.000 and k 0.000, respectively). Overall image quality and confidence scores of CTA were significantly higher compared to MRA at all ages (2.8/3 vs. 2.3/3, p = .001; and 2.9/3 vs. 2.5/3, p = .003, respectively). Movement artifacts were significantly lower in CTA compared to MRA in children ≥6 years (1.0/3 vs. 1.7/3, p = .010, respectively). CTA is preferred over fl3D-ce MRA for the preoperative assessment of hepatic artery anatomy in children receiving LT, both at ages <6 years and ≥6 years.

Wait-list mortality of young patients with Biliary atresia: Competing risk analysis of a eurotransplant registry-based cohort.

Liver transplantation (LT) is the standard treatment for biliary atresia (BA) patients with end-stage liver disease. The prognosis after LT has steadily improved, but overall prognosis of BA patients is also determined by mortality before LT. We aimed to quantify mortality in young BA patients on the Eurotransplant waiting list and to determine the effect of disease severity and age at time of listing on pretransplant mortality. We used a cohort study design, which incorporated data from the Eurotransplant registry. Participants were 711 BA patients who were below 5 years of age from 5 countries and listed for LT between 2001 and 2014. We applied a competing risk analysis to evaluate simultaneously the outcomes death, LT, and still waiting for a suitable organ. We used Cox proportional hazards regression to assess 2-year mortality. In a subcohort of 416 children, we performed multivariate analyses between 2-year mortality and disease severity or age, each at listing. Disease severity at listing was quantified by the Model for End-Stage Liver Disease (MELD) score, which assesses bilirubin, creatinine, albumin, and international normalized ratio as continuous variables. Two-year wait-list mortality was 7.9%. Age below 6 months and MELD score above 20 points, each at listing, were strongly and independently associated with 2-year mortality (each P < 0.001). A total of 21% of infants who fulfilled both criteria did not survive the first 6 months on the waiting list. In conclusion, our findings quantify mortality among young BA patients on the waiting list and the relative importance of risk factors (age and severity of disease at listing). Our results provide both an evidence base to rationally address high mortality in subgroups and a methodology to assess effects of implemented changes, for example, in allocation rules. Liver Transplantation 24 810-819 2018 AASLD.