Abnormal Anatomical Variations of Extra-Hepatic Biliary Tract, and Their Relation to Biliary Tract Injuries and Stones Formation

Background: To determine the most common abnormal anatomical variations of extra-hepatic biliary tract (EHBT), and their relation to biliary tract injuries and stones formation. Methods: This is a retrospective review of 120 patients, who underwent endoscopic retrograde cholangiopancreaticography (ERCP) and/or magnetic resonance cholangiopancreaticography (MRCP), between July 2011 and June 2013. The patients' ERCP and MRCP images were reviewed and evaluated for the anatomy of EHBT; the medical records were reviewed for demographic data, biliary tracts injuries and stones formation. Results: Out of 120 patients, 50 were males (41.7%) and 70 were females (58.3%). The mean age was 54 years old (range 20 - 88). Abnormal anatomy was reported in 30% (n = 36). Short cystic duct (CD) was found in 20% (n = 24), left CD insertion in 5% (n = 6), CD inserted into the right hepatic duct (RHD) in 1.7% (n = 2), duct of Luschka in 3.33% n = 4) and accessory hepatic duct in also 3.33% (n = 4). Biliary tract injuries were reported in 15% (n = 18) and stones in 71.7% (n = 86). Biliary tract injuries were higher in abnormal anatomy (P = 0.04), but there was no relation between abnormal anatomy and stones formation. Conclusion: Abnormal anatomy of EHBT was found to be 30%. The most common abnormality is short CD followed by left CD insertion. Surgeons should be aware of these common abnormalities in our patients, hence avoiding injuries to the biliary tract during surgery. The abnormal anatomy was associated with high incidence of biliary tract injury but has no relation to biliary stone formation.