Computer-Assisted Surgery Planning for Complex Liver Resections

Abstract

The purpose of this study was (1) to compare 2-dimensional computed tomographic (2D-CT) and 3D-CT computer-assisted preoperative surgical planning, and (2) to define the indications for the latter method. The determination of functional residual liver volumes and the imaging of intrahepatic anatomy are critical when planning complex liver resections. Prospective study of 202 consecutive patients who underwent high-risk procedures (extended right/left hepatectomies, central resections, polysegmentectomies, large atypical resections, repeated resections, and hepatectomies in the setting of abnormal liver parenchyma). Preoperative evaluation included 3D-CT computer-assisted surgical planning (3D-CASP) and conventional 2D-CT imaging. Endpoints of the study were (1) determination of resectability and (2) changes in operative strategy (resection modifications/extensions/intrahepatic vascular reconstructions). Thirty-four of 202 cases were considered nonresectable on the basis of both 2D and 3D imaging results. In 56 (33%) instances, 3D-CASP either changed the 2D strategy (expansion of resection, n = 40; intrahepatic vascular reconstructions, n = 13) or provided an entirely different approach (n = 3). Eleven (5.4%) cases were considered unresectable at laparotomy on the basis of poor liver quality (n = 8) or unfeasible vascular reconstructions resulting in remnants too small to sustain physiologic function (n = 3). Significant differences between resectional 2D and functional 3D remnant liver volumes were observed in extended left hepatectomies and left trisectionectomies. 3D-CASP was particularly helpful in patients with unconventional resection planes and in those with central left tumors. Its main advantages were the individualized inflow/outflow virtual analyses and the accurate determination of safely perfused/drained retained liver volumes.