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).