The Hidden Risk in Calot’s Triangle: Moynihan’s Hump in Laparoscopic Cholecystectomy

Abstract

Caterpillar or Moynihan’s hump is a rare variation of the right hepatic artery, in which the vessel follows a tortuous course close to the gallbladder and is often associated with a short cystic artery (CA). This configuration increases the risk of vascular injury during cholecystectomy. We report a case of a 32-year-old woman with acute calculous cholecystitis who underwent elective laparoscopic cholecystectomy 4 weeks after conservative management. Intraoperatively, a prominent pulsatile vessel consistent with Moynihan’s hump was identified behind the cystic duct (CD). After careful dissection and confirmation of the critical view of safety, the CD and short CA were clipped separately, allowing uneventful completion of the procedure. This case highlights the clinical relevance of recognizing vascular variations in Calot’s triangle and emphasizes meticulous dissection, anatomical awareness, and safe surgical principles to prevent major vascular complications.