Accurate preoperative estimation of liver-graft volumetry using three-dimensional computed tomography

Background. The aim of this study was to clarify the value of three-dimensional computed-tomography (3D-CT) volumetry for size matching in living-donor liver transplantation (LDLT). Methods. 3D-CT volumetry was applied to 25 donors who underwent hepatectomy for a living relative needing an orthotopic liver transplantation. Fifteen patients underwent extended left lobectomy, one patient an extended left lateral lobectomy, and nine patients right lobectomy. 3D-CT imaging was performed with the workstation ZIO M900 (Zio Software Inc., Tokyo, Japan). The estimated volume of the grafts in two-dimensional (2D) and 3D images were compared, and an error ratio was calculated. Results. 3D-CT imaging revealed the anatomy of the hepatic vein bifurcation and the shape of the graft. The error ratio was 12.8±2.3% in 3D, compared with 19.4±2.5% in 2D. As such, 3D-CT volumetry appears to be more exact than conventional 2D-CT volumetry, but volumetry by 3D-CT still produces an error ratio of approximately 13%. The weight transition of the rats' livers under preservation in University of Wisconsin (UW) solution indicated that the graft volume seems to decrease during perfusion with UW solution. Mismatch of the cutting line and volume reduction by dehydration (approximately 5% reduction 1 hour after perfusion) seems to cause the error in 3D-CT volumetry. Conclusions. Three-dimensional CT volumetry is useful for size matching in cases of living-related orthotopic liver transplantation.