Impact of graft type on remnant liver regeneration: right hepatectomy versus extended right hepatectomy.

Right hepatectomy with the middle hepatic vein (MHV) affects venous return and function of the remaining liver. We compared the remnant liver volume in the donors of resection with or without the MHV on the remnant liver volume regeneration. Living donors who had undergone right hepatectomy without MHV (RH group; n = 36) and those with MHV (ERH group; n = 19) were reviewed. Volume regeneration of segments I-III, segment IV, and total remnant liver volume was assessed at postoperative day (POD) 7 and 30 using a computed tomography-based volumetry program. According to the measured volume data, we calculated the liver remnant volume and the rate of liver remnant volume increase. The regeneration rate of segment IV was significantly low in the ERH group compared with that in the RH group at POD 7 and POD 30 (160% vs 141%; P = .018 and 189% vs 154%; P = .007). In contrast, the regeneration rate of the total remnant liver volume was not significantly different between the 2 groups (173% vs 175%; P = .758 and 199% vs 198%; P = .880). In conclusion, extended right hepatectomy can be safely performed with careful preoperative evaluation without significant impairment of remnant liver regeneration.