Liver regeneration at day 7 after right hepatectomy: global and segmental volumetric analysis by using CT.

ABSTRACT

PURPOSE: To evaluate total and segmental liver regeneration by comparing preoperative computed tomographic (CT) volumetry and CT volumetry on postoperative day 7 following right hepatectomy and to study liver regeneration estimated by using CT volumetry in patients with different surgical indications and in whom the middle hepatic vein (MHV) was harvested or not harvested. MATERIALS AND METHODS: Local medical ethics committee and state medical board approval and informed consent were obtained. Twenty-seven patients who had undergone right hepatectomy were imaged with multidetector CT preoperatively and at day 7 postoperatively. Fourteen patients (group 1) were living liver donors, including eight in whom the MHV was harvested. Thirteen patients (group 2) underwent right hepatectomy for other indications. Volumetric measurements were performed semiautomatically. Total volumes and segmental volumes were measured for total liver, future liver remnant (FLR), and liver remnant. Total and segmental early regeneration index, defined as [(V(LR) - V(FLR))/V(FLR)] x 100, where V(LR) is volume of the liver remnant and V(FLR) is volume of the FLR, were calculated. Comparisons were performed by using the Mann-Whitney test, and a P value of less than .05 was considered significant. RESULTS: The liver remnant at day 7 showed a 64% increase in volume from the FLR, without a significant difference between groups 1 and 2. In the group with harvesting of MHV, volume and segmental regeneration index were significantly lower than in other patients, for both the caudate lobe (32 and 48 mL, respectively; P = .049) and liver segment IV (Couinaud) (206 and 334 mL, respectively; P = .008). CONCLUSION: Segmental regeneration of the liver following right hepatectomy varies, depending on whether the MHV was harvested, and seems to be related to hepatic outflow.