Prevalence of hepatic vascular anomalies in consecutive contrast-enhanced computed tomography images — a retrospective observational study

Background Liver is a complex, highly vascular organ, where anatomical variations are the norm.

This study aimed to analyze all the three hepatic vascular anatomical variations in a single study which would help us understand the prevalence of hepatic vascular (arterial, portal, venous) anomalies in the population catered to by our institution.

Methods A retrospective analysis of 545 contrast-enhanced CT scans was done from November 2019 from the institute PACS after satisfying the inclusion and exclusion criteria.

The raw imaging data were processed in PACS software — Centricity™ Universal Viewer and Syngo.via Vb20 platform, for axial, coronal, and axial-oblique multiplanar reformation, maximum intensity projection (MIP), and volume rendering (VR) images.

Data were analyzed in the three vascular phases to determine the anatomical variations.

Analysis was done by two surgical residents in the division of HPB surgery, which was verified by a certified radiologist.

Results There were no major differences in the prevalence rates of the vascular anomalies across gender and domicile distributions.

The prevalence of normal hepatic artery and variant hepatic artery in our study was 69% and 31%, respectively.

Accessory left hepatic artery (10%) was the most common hepatic artery variant in our study.

Single RHV was seen in 77.4%, and other RHV variants like two RHV with common trunk, two RHV with independent drainage, and three RHV with common trunk contribute 22.6% of our study population.

Accessory inferior RHV was seen in 19.8% of the study population.

Normal portal vein anatomy was found in 81.1% in our study, and the most common variant in our study population was trifurcation of portal vein (16.1%).

Conclusion This was the largest study until date from South India, studying all three hepatic vascular anatomical variations in a single study.

Variations in the anatomy of hepatic arteries, portal veins, and hepatic veins are common.

A good knowledge of the same is necessary especially for a hepatobiliary surgeon or for an interventional radiologist, to plan and avoid complications during a procedure.

Preoperative contrast-enhanced CT scan and whenever necessary a VR or a MIP reconstruction will precisely help in identifying these variations.