Preduodenal portal vein: two distinct case reports with unique presentations and tailored surgical management strategies.

Preduodenal portal vein (PDPV) is a rare congenital vascular malformation, which was first described by Knight in 1921 as an anomalous vein that lies in front of the duodenum, common bile duct, and hepatic artery instead of beneath them. This abnormal position may result in congenital duodenal obstruction and puts it in danger during operations around this region. PDPV is typically associated with other congenital anomalies, mainly intraabdominal and cardiac ones. The surgical management is usually determined intraoperatively based on evidence that the PDPV is the real cause of obstruction. We report two cases of PDPV each with a different presentation and management approach.