Anatomic variations of hepatic artery and new clinical classification based on abdominal angiographic images of 1200 cases.

Background/aims: There is wide variation in the branches of the hepatic artery. We aimed to classify these variations clinically on the basis of abdominal angiographic images in order to find out the suitable classification.

Methodology: Anatomic variations of the hepatic artery of 1200 patients were analyzed at Tokyo Women's Medical University from 2000 to 2010, and Classified into four categories: "Y", "I-I", "Y plus I", and "I-I plus I". Patients with a proper hepatic artery were categorized as "Y", and those without as "I-I", to describe the arteries morphologically. We denoted an accessory artery as "I", and described it as being to the left or right of "Y"; i.e., "I, Y" or "Y, I", respectively.

Results: Normal hepatic anatomy was observed in 77.2% (926 subjects), and variations were found in 22.8% (274 subjects). Of all the patients, 3.8% (45 subjects) could not be classified using Michels' classification. On the other hand, when variations were classified using our classification, all variations could be classified into either Category Y (85.6%, 1027 subjects) or Category I-I (14.4%, 173 subjects).

Conclusions: Our simplified new clinical classification of hepatic artery variants would be useful for preoperative planning in hepato-biliary-pancreatic surgery and liver transplantation.