Surgically Important Anatomic Variations of Extrahepatic Biliary System Among Black Kenyan Cadavers at Moi University Human Anatomy Laboratory

Abstract

Background: Anatomical variations of the human body including the extra hepatic biliary system exist across various individuals. Understanding the variant anatomy of the extrahepatic biliary system aids surgeons in avoiding iatrogenic injuries. This is important in resource limited settings where it is not possible to perform adequate radiological investigations of the hepatobiliary system prior to surgery. This study described the anatomic variation of the extrahepatic biliary system among Kenyans. Methods: This was a cross-sectional study conducted at Moi University Anatomy Laboratories among 42 adult cadaveric specimens. Specimen dissections were conducted as per the fifteenth edition of Cunningham manual of Practical Anatomy. The variant anatomy data collected were filled in a structured data collection form, analyzed and presented using descriptive statistics. Study Findings: Of the 42 cadavers sampled, 62% (n=26) were male while 38% (n=16) were female. All had a gall bladder being drained by the cystic duct. The length of the cystic duct ranged between 7-35 mm joining the common hepatic duct to form the common bile duct in 98% (n=41) of all the cadavers sampled. This confluence was to the left in 7.1% (n=3), right 42.9% (n=18), anteriorly in 14.3% (n=6) and posteriorly 35.7% (n=14). A single cadaver (2%) had the cystic duct drain into the right hepatic duct. Two thirds (66.7%; n=28) of the cadavers sampled had the confluence of the right and the left hepatic duct outside the liver. There were no cholecystohepatic ducts in this study. Conclusion: The study determined the existence of surgically important variant anatomy of the extrahepatic biliary system. There is need for greater appreciation of the extrahepatic biliary system variant anatomy by both surgeons and radiologists so as to decrease morbidity and improve on surgical outcomes.