Anatomic Variation of the Cystic Artery: New Findings and Potential Implications

Purpose: To determine the anatomy of the cystic artery by dual-source CT, and correlate imaging findings with those patients who had laparoscopic cholecystectomy (LC). Materials and Methods: Following institutional review board approval, a total of 289 consecutive patients (204 men and 85 women) were evaluated with CT for abdominal pain, including 55 patients subsequently underwent LC. Location of the cystic artery termination, distance between the cystic artery origin and the gallbladder, and angle between the cystic artery and its parent artery were evaluated by two radiologists. The laparoscopic surgical video record (gold standard) was similarly evaluated by a surgeon. Results: A total of 256 cystic arteries in the 247 patients were included. Cystic artery terminations are predominately found in ventral Calot triangle plane (50.8%, type II). Cystic artery origin immediately adjacent to the gallbladder surface was seen in 11/256 (4.3%). Zero angle between the cystic artery and its parent artery was found in 17 of 256 cystic arteries (6.6%). The cystic arteries and the Calot triangle were depicted in 49 patients (95% confidence interval: 85%, 97%). For all 49 patients, CT imaging findings were consistent with surgical video records. No case involved vascular and biliary injury occurred. Conclusions: Given the large number of LC performed each year, better knowledge of anatomic variation of the cystic artery could potentially prevent arterial injury and bile duct injury, particularly for patients with unusual anatomy.