Visualization of the segment IV hepatic artery using 128-section MDCT angiography

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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

Two novel hepatic arterial variations in a living liver donor detected by multidetector computed tomography angiography

PURPOSE

Considering that the knowledge of variations in the hepatic vascular structure is essential for hepatic surgery and liver transplantation, we aimed to present a rare case of the anatomic variation of arterial blood supply to the liver to help prevent complications and choose suitable donors.

METHODS

We present a novel variant in this case report (living liver donor), an accessory right hepatic artery (supplying segment 6) originating from the dorsal pancreatic artery and a middle hepatic artery (supplying segment 4) arising from the pancreaticoduodenal artery (first branch of the gastroduodenal artery). Preoperative diagnosis was made using computed tomography angiography (CTA) with multiplanar reformate (MPR) images, curved planar reformate (CPR), maximum intensity projection (MIP) images and three-dimensional volume renderings (3D VR).

RESULTS

To the best of our knowledge, this is the first case in the English literature describing this type of variation. A search for new donors began since the living liver donor was not suitable due to the very thin segment 4 artery, posing potential risks for the donor and the thin segment 6 artery being a complicating factor for anastomosis.

CONCLUSIONS

The preoperative knowledge of liver blood supply has great importance in planning surgery and transplantation. CTA, reformate and reconstruction techniques allow for the evaluation of difficult and complex anatomic variations.