Reliable Estimation of Preoperative Graft Volume in Living Donor Liver Transplantation

Abstract

Aims & Objectives: Corner stone in performing living donor liver transplant is to assess and predict the adequacy of the donated liver for recipient and remaining liver. Previously the conversion of liver volume to estimated weight is done by using unit to unit conversion with a factor of 1. We analyzed data of our institute to research the methodology and local applicability of the same. Place and duration of study: Shaikh Zayed Hospital, Lahore. January 2011 to June 2017 Material & Methods: Retrospective data was collected for the first 115 recipients and donors. Their preoperative liver volumes calculated by C.T scan and post-operative graft harvested with weights were compared. Results: The parameter of actual volume of right lobe averaged to 769.77 ± 12.73 gm varying with a quantum of 17.73% (426 – 1123 gm). Estimated volume of right lobe of liver varied 358 to 1218 ml (CV = 17.84%) with an average value of 798.96 ± 13.29 ml. Results of linear regression between estimated volume of right lobe and actual weight of the right lobe in gm was significantly linear (r = 0.830, r2 = 0.690, adj. r2 = 0.689 and F = 250.98, p < 0.0001), showing that volumetric assessment overestimated graft weight/volume. Following is equation generated from our data for graft weight estimation. Actual right lobe (g) = 134.004 + 0.796 (estimated right lobe volume (ml) ± 76.42. Conclusion: Using one to one principle for volume estimation of healthy liver can be misleading and therefore we propose an equation to reach more accurate estimation of graft weight. Keywords: living donor liver transplant, CT volumetry, graft to body weight ratio