Correlation between CT volumetry and actual graft weight in living donor liver transplants in South Africa

Abstract

Background: Liver transplantation is the definitive management for patients with end-stage liver disease. Preoperative computed tomography (CT) is used in living donor liver transplant (LDLT) for donor and graft selection as well as predicting graft weight. Objectives: The aim of this study is to establish the relationship between estimated graft volume (EGV) and actual graft weight (AGW) and ascertain a correlation coefficient that will improve the accuracy of EGV in a South African population. Method: The study included 117 LDLT between March 2013 and August 2022. Of these, 86 were left lateral (LL), 15 right lobe (R), 10 left lobe with caudate (LC), five left lobe (L) and one segment two (monosegment) grafts. Estimated graft volume and actual graft weight were compared using the Pearson coefficient and the relationship was illustrated with scatter plots. Results: Estimated graft volume and AGW had a strong positive correlation with a Pearson correlation (R) of 0.95 (p 0.001). The relationship was significantly linear with a correlation coefficient of 0.71. The mean EGV was significantly higher than that of AGW (388 mL ± 249 mL vs. 353 g ± 184 g) with overestimation in 61% of cases. Left lateral and R grafts were the most prevalent LDLT graft type, both having a strong linear correlation between EGV and AGW. Conclusion: Applying a correlation coefficient of 0.71 will improve the accuracy of CT volumetry graft weight predictions. Contribution: A unique correlation coefficient will improve EGV accuracy, aiding in preoperative planning and mitigating post-operative complications in both donors and recipients.

Keywords

• living donor liver transplant
• liver transplantation
• end-stage liver disease
• ct volumetry
• graft weight