Replaced common hepatic artery from the superior mesenteric artery: multidetector computed tomography (MDCT) classification focused on pancreatic penetration and the course of travel

We categorize the subtypes of the replaced common hepatic artery (RCHA) and evaluate the clinical implications.

Thirty-four cases of the RCHA were evaluated retrospectively using multidetector computed tomography. We categorized them into the three RCHA subtypes according to pancreatic penetration and the passing routes. The distance between the orifice of the superior mesenteric artery (SMA) and RCHA bifurcation (D _SMA-RCHA) was measured using advanced 3D imaging software. Analysis of variance was used to evaluate the difference in D _SMA-RCHA according to the RCHA subtype.

Type A (n = 17, 50 %) referred to RCHA penetrating the pancreatic parenchyma, all crossing the dorsal aspect of the superior mesenteric vein (SMV). Among them, three cases were accompanied by the circumportal pancreas. Type B (n = 10, 29 %) referred to RCHA without penetration of the pancreatic parenchyma and crossing of the dorsal aspect of the main portal vein (MPV) or SMV. Type C (n = 7, 21 %) referred to RCHA without penetration of the pancreas parenchyma and crossing of the ventral aspect of the MPV or SMV. The mean D _SMA-RCHA of each subtype was as follows: type A, 3.13 cm [95 % confidence interval (CI) 2.70–3.57]; type B, 2.04 cm [95 % CI 1.40–2.68]; and type C, 2.14 cm [95 % CI 2.23–2.92]. The D _SMA-RCHA of the penetrating pancreatic parenchyma of the RCHA was significantly longer than that of the non-penetrating pancreatic parenchyma (P = 0.007).

Half of RCHA show penetrating the pancreatic parenchyma, which was categorized as type A, and this type A takes off from the SMA more distally than RCHA without intrapancreatic penetration.