Evaluation of the Concordance of Portal Vein and Biliary Duct Variations: A Retrospective Donor Series

BACKGROUND Knowledge of the concordance between portal vein (PV) and bile duct (BD) anatomy is essential for planning living donor liver transplantation (LDLT) and hepatobiliary surgery. Unrecognized variants can result in bile leakage, vascular injury, or graft-related complications; therefore, accurate preoperative mapping is mandatory. Because the PV and BD systems develop in parallel during embryogenesis, an anatomical relationship between them has been proposed, but available data remain limited and inconsistent. This retrospective study of 423 living liver donors aimed to evaluate the association between PV and BD types and to determine whether biliary anatomy can be anticipated from preoperative vascular imaging. MATERIAL AND METHODS Donor grafts were categorized as right or left lobe. Portal vein anatomy was assessed with triphasic CT angiography. Intraoperative cholangiography (IOC) was routinely performed for every donor to define BD anatomy. RESULTS A statistically significant association was found between PV and BD types (P=0.0028). BD variations were more frequent in donors with PV Type 2 and Type 3. Notably, 21% of donors with PV Type 1 had BD Type 3. In right-lobe donors, "classical concordance" (PV1-BD1) was observed in 57.7% (n=222), whereas in left-lobe donors it was 34.2% (n=13). Overall "anatomical concordance" (direct PV-BD type match) was 64.9% in right-lobe and 52.6% in left-lobe donors. CONCLUSIONS PV and BD anatomies are significantly related, supporting the concept of parallel embryological development. However, relevant biliary variants can occur even in donors with normal PV anatomy, particularly in left-lobe grafts. Thus, PV type alone is not sufficient to predict biliary complexity, and IOC together with meticulous preoperative evaluation remains essential in LDLT.