An anatomical study of Moynihan's hump of right hepatic artery and its surgical importance

Tortuous course of right hepatic artery , also known as Moynihan's hump or caterpillar hump is a rare but important anomaly to be recognized to prevent intraoperative vascular and biliary injuries during surgical procedures involving the liver and biliary apparatus. The present study is intended to know the incidence and anatomy of the Moynihan's hump of right hepatic artery emphasizing its relevance in current surgical practice. The present study was conducted on 40 adult cadavers of both sexes allotted to undergraduate students at Bangalore Medical College and Research Institute, Bangalore and Shimoga Institute of Medical Sciences, Shimoga. The right hepatic artery was exposed by dissection method and was observed for the presence of caterpillar hump. Out of 40 cases, caterpillar hump of right hepatic artery was found in two cases (5%). One case showed the presence of single loop facing downwards and the other showed double loops, proximal loop facing upwards and the distal loop toward the right. The cystic artery arising from the double looped right hepatic artery was short. Knowledge of anatomy and recognition of vascular variations are essential prerequisites for safe and uneventful laparoscopic cholecystectomy .