Portal and Hepatic Venous Territorial Mapping in Healthy Human Livers: Virtual Three-Dimensional Computed Tomography Size-Shape-Topography Study.

OBJECTIVES

This study aimed to assess portal and hepatic venous volumes as related to the planning of complex liver resections and segmental liver transplant.

MATERIALS AND METHODS

We analyzed 3-dimensional computed tomography of portal and hepatic vein territorial maps of 140 potential living related liver donors. Portal and hepatic vein maps were simulated both separately and in overlap (cross-mapping) to calculate inflow and outflow volumes.

RESULTS

In total liver volume, the right hemiliver was always dominant (mean 64.7 ± 4.8%) and the right medial sector (mean 36.4 ± 6.8%) and segment 8 (mean 19.1 ± 4.3%) accounted for the largest volumes, whereas the left medial sector(mean 13.5 ± 3.1%) and segment 4A (mean 5.8 ± 1.8%) accounted for the smallest volumes (with exclusion of caudate lobe). The right hepatic vein was dominant for both right hemiliver and right lateral sector and had the largest drainage volume in total liver volume (mean 40.0 ± 11.2%). The left hepatic vein was dominant for both left hemiliver and left lateral sector but had the smallest drainage volume fortotal liver volume (mean 21.3 ± 5.0%). The middle hepatic vein drained 50.2 ± 12.5% of the right medial sector and 75.8 ± 15.4% of the left medial sector. In 67 cases, an accessory vein (inferior hepatic vein) drained 16.5 ± 13.2% ofthe right hemiliver, 31.4 ± 25.1% ofthe right lateral sector, 26.6 ± 23.2% of segment 7, and 37.4 ± 31.3% of segment 6.

CONCLUSIONS

The portal and hepatic vein territorial anatomy was characterized by extensive individual variability. An extremely smallremnant volume (<25% of total liver volume) precluded a minority of virtual extended left and a majority of extended right hepatectomies. Left trisectionectomy was associated with risky drainage from the middle hepatic vein, extensive segment 6 remnant congestion volume in 8% of cases, and right lateral sector-favorable inferior hepatic vein large drainage pattern in 13% of livers.