Diagnosing portal vein stenosis after pediatric liver transplantation: A systematic review

Portal vein stenosis (PVS) is a relatively frequent vascular complication after pediatric liver transplantation (pLT) that may result in portal hypertension. The aim of this study was to provide an overview of various diagnostic methods and imaging criteria used to diagnose PVS and to report their diagnostic accuracy. Until August 2024, PubMed and Embase were searched for English-language manuscripts with >5 patients and radiologic features of PVS. Three investigators screened articles and extracted data. The risk of bias was assessed using QUADAS-2. Twenty studies were identified. Doppler ultrasound (DUS) was the most used imaging method, followed by computed tomography (CT) and digital subtraction angiography (DSA). In studies comparing DUS with other diagnostic modalities, an elevated peak systolic velocity (PSV) and velocity ratio (VR) emerged as reliable indicators of PVS. An anastomotic diameter of <3.5 mm showed the best diagnostic performance, with a sensitivity of 100 % and a specificity of 91.8 %. Although DUS is the preferred initial diagnostic tool due to its non-invasive nature, CT and DSA remain essential in cases where DUS findings are inconclusive or when more detailed vascular assessment is necessary. DSA also allows for simultaneous endovascular treatment, further enhancing its utility. This systematic review emphasizes the need for larger, prospective studies to directly compare the diagnostic performance of these imaging modalities and to establish more consistent and reliable criteria for diagnosing PVS after pLT.