Anatomical variations of hepatic veins: three-dimensional computed tomography scans of 200 subjects.

BACKGROUND: The impact of hepatic venous anatomic variations on hepatic resection and transplantation is the least understood aspect of liver surgery. METHODS: A prospective three-dimensional computed tomography study was undertaken on 200 consecutive subjects with normal livers to determine the prevalence of surgically significant hepatic venous anatomic variations. RESULTS: The prevailing pattern of the three hepatic veins in these subjects was a right hepatic vein (RHV) and a common trunk for the middle (MHV) and left (LHV) hepatic veins (122/200, 61%). The remaining patients had the RHV, MHV, and LHV draining independently into the inferior vena cava (IVC). In 39% of patients, the RHV was small and was compensated by a large right inferior hepatic vein (21.0%), an accessory RHV (8.5%) or a well-developed MHV (6.5%). A segment 4 vein was seen in 51.5% of patients. This segment 4 vein joined the LHV (26%), the MHV (17.5%), or the IVC (8%). An umbilical vein and a segment 4 vein were seen in 3.5% of patients. These two veins joined either the LHV (2.0%) or the MHV (1.5%). CONCLUSIONS: Knowing the variations of hepatic veins before surgery is useful during both partial hepatectomy and donor operations for living related liver transplantation.