Regional morphometry and anatomical variations of the arteria hepatica propria, hepatic veins and portal vein

Despite significant advancements in liver and microvascular reconstructive surgery, vascular complications remain a major cause of morbidity and mortality. Therefore, thorough preoperative evaluation of the organ's vascular structures is of paramount importance. Accurate identification of anatomical features and potential variations in vascular structures can not only reduce complications in both donors and recipients but also substantially improve surgical outcomes. In liver transplantation, a detailed understanding of the anatomy and variations of the arteria hepatica propria, vena portae hepatis, and venae hepaticae is essential. In this study, we evaluated arterial and portal phase computed tomography (CT) images of 900 individuals who presented to Fırat University Medical Faculty Hospital. Patients with a history of liver resection, congenital anomalies, or hepatic tumors or hydatid cysts were excluded from the study. We assessed anatomical variations of the arteria hepatica propria supplying the right and left lobes of the liver, vena portae hepatis, and venae hepaticae, along with the distribution of variation types according to sex and age, and measurements of vessel diameter and length across types. Chi-square test was used to compare categorical variables by type groups. For non-normally distributed diameter and length measurements, Kruskal-Wallis test was employed for overall group comparisons, and Mann-Whitney U test for pairwise comparisons. Michels Type 1, representing the classical anatomy of the arteria hepatica propria, was identified in 57.3% of individuals. This variation also exhibited the highest mean diameter, while the lowest diameter was observed in Type 8. The greatest vessel length was recorded in Type 2, whereas the shortest was noted in Type 7. According to Covey's classification, Covey Type 1 reflecting the typical anatomical distribution of the vena portae hepatis was present in 55.7% of the population. The greatest length of this vessel was found in Type 4, while the shortest was observed in Type 1. In 54.3% of participants, the vena hepatica sinistra and vena hepatica intermedia converged into a single trunk before draining into the inferior vena cava. This type demonstrated the largest vessel diameter among all variations. The findings of this study offer valuable insights into hepatic vascular variations and are expected to enhance the safety and efficacy of surgical planning. We believe these data will serve as a reference for future research and contribute significantly to the refinement of surgical approaches through a more detailed understanding of anatomical variations. Keywords: Liver, arteria hepatica propria, vena portae hepatis, venae hepaticae, variation.