Can ultrasonography differentiate anastomotic and non-anastomotic biliary strictures after orthotopic liver transplantation- a single-center experience.

Purpose: To evaluate the role of ultrasonography (US) in differentiating anastomotic biliary strictures (AS) and non-anastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT).

Method: This retrospective study included 1259 OLT recipients between 2005-2018. Seventy-six with anastomotic strictures (AS) and 103 with non-anastomotic strictures (NAS) were analyzed. The reference standard was cholangiography. The sensitivity, specificity, accuracy of US was evaluated.

Results: There were significant differences between AS and NAS groups (p < 0.001) for skipped and irregular dilatation of intrahepatic bile duct and visualization of hilar biliary lumen. The better US imaging feature for NAS was poorly visualized and non- visible hilar bile duct luminal contour. The sensitivity, specificity and accuracy were 94.2 %, 84.2 % and 88.9 % respectively. Combined two predictors greatly increased the specificity to 93.4 % while diminished its sensitivity and accuracy.

Conclusion: US is useful and efficient to differentiate AS and NAS after OLT.