Discrepancy between estimated and actual weight of partial liver graft from living donors

Abstract

A discrepancy between the actually obtained graft weight and the preoperative volumetric estimation is often observed in living donor liver transplantation. The aim of the study reported here was to clarify the prevalence and degree of this discrepancy between estimated and actual liver volume. Preoperative volumetric evaluations of 26 live donor livers were performed using three-dimensional computed tomography software. The weight of the liver graft and blood contained in the graft were measured immediately after procurement and compared with the preoperative estimate. The graft was also weighed after perfusion and after back-table procedures. Analysis of the results revealed that blood-free graft weight was significantly overestimated (p=0.02) and blood weight was significantly underestimated (p<0.001). The sum of the weight of the graft and blood best corresponded to the preoperative volume estimate (R (2)=0.64, p<0.001). The back-table procedures significantly decreased the weight of the liver graft (p<0.001). Graft weight after perfusion and after venous reconstruction corresponded to 95 and 90% of the weight obtained before perfusion, respectively. Multivariate analysis revealed that donor age had the most significant influence on the ratio of the weight decrease in the University of Wisconsin solution (p=0.03). The weight of liver grafts decreases significantly during back-table procedures. Underestimation of the blood weight contained in the graft is one cause of the graft weight discrepancy, but weight loss while the graft was immersed in the University of Wisconsin solution was also observed. These phenomena should be taken into account when graft size is being determined.