Novel embryological classifications of hepatic arteries based on the relationship between aberrant right hepatic arteries and the middle hepatic artery: A retrospective study of contrast-enhanced computed tomography images.

Abstract

Variations in hepatic arteries are frequently encountered during pancreatoduodenecomy. Identifying anomalies, especially the problematic aberrant right hepatic artery (aRHA), is crucial to preventing vascular-related complications. In cases where the middle hepatic artery (MHA) branches from aRHAs, their injury may lead to severe liver ischemia. Nevertheless, there has been little information on whether MHA branches from aRHAs. This study aimed to investigate the relationship between aRHAs and the MHA based on the embryological development of visceral arteries. This retrospective study analyzed contrast-enhanced computed tomography images of 759 patients who underwent hepatobiliary-pancreatic surgery between January 2011 and August 2022. The origin of RHAs and MHA courses were determined using three-dimensional reconstruction. All cases of aRHAs were categorized into those with or without replacement of the left hepatic artery (LHA). Among the 759 patients, 163 (21.4%) had aRHAs. Five aRHAs patterns were identified: (Type 1) RHA from the gastroduodenal artery (2.7%), (Type 2) RHA from the superior mesenteric artery (SMA) (12.7%), (Type 3) RHA from the celiac axis (2.1%), (Type 4) common hepatic artery (CHA) from the SMA (3.5%), and (Type 5) separate branching of RHA and LHA from the CHA (0.26%). The MHA did not originate from aRHAs in Types 1-3, whereas in Type 4, it branched from either the RHA or LHA. Based on the developmental process of hepatic and visceral arteries, branching of the MHA from aRHAs is considered rare. However, preoperative recognition and intraoperative anatomical assessment of aRHAs is essential to avoid injury.