Conceptual framework of middle hepatic vein anatomy as a roadmap for safe right hepatectomy.

BACKGROUND

While the middle hepatic vein (MHV) guides parenchymal transection during right hepatectomy, its most proximal tributaries can be difficult to identify, and injury to its tributaries can be a source of major bleeding.

METHOD: Following simulation modeling of right hepatectomy, reconstructed MHV data was pooled from 40 patients. MHV-tributaries and MHV-relationship to the portal pedicle were mapped out to facilitate their identification from the beginning of parenchymal transection.

RESULTS

Hotspots for injury were identified: A median of 1 (1-3) tributaries draining segment 5 (V5) were within 45-90mm from the MHV termination, and 16mm above and 22mm caudal to the portal trunk. Simulation demonstrated a constant anatomic relationship between portal pedicle and the proximal MHV. A median of 2 (0-4) tributaries draining segment 8 (V8) were located 9-35mm from the MHV termination. This information was compiled into an "MHV-road-map" demonstrating 86% of the MHV tributaries at risk for significant bleeding are within 15mm of the MHV, while only thin tributaries are located in the outer area.

CONCLUSIONS

The MHV-road-map led to a peripheral-to-central parenchymal transection approach to minimize the risk of MHV-injury thereby reducing bleeding during open and minimally invasive right hepatectomy.