Correlating CT Volumetry with Actual Graft Volume in Living Donor Liver Transplantation: A Retrospective Analysis

Abstract

Introduction: Liver transplantation offers a crucial treatment for end-stage liver diseases. Living donor liver transplantation (LDLT) is gaining prominence, especially in areas with deceased donor scarcity. Accurate preoperative liver volume assessment is critical in LDLT for predicting outcomes for the donor and recipient. This study focuses on evaluating the correlation between preoperative CT liver volume and actual intraoperative graft weight during LDLT at the Pakistan Kidney and Liver Institute and Research Centre. Methods: A retrospective study of 472 liver donors was conducted between March 2019, and July 2023. Donors who underwent liver volume assessments for transplantation purposes were included. Those with liver steatosis, suboptimal liver volume, significant liver anomalies, and uncommon anatomical variations were excluded. CT scans were executed with a 128 slice GE Healthcare system, followed by volumetric reconstructions. The graft volume was determined post-resection by physically weighing the graft. Pearson's correlation analyzed the relationship between preoperative liver volume and intraoperative graft weight. Results: Among 472 donors, 56.36% were males (n = 266) and 43.64% females (n = 206). The average CT-predicted donor graft volume was 717.59 mL, while the actual post-operative graft weight averaged at 618.53 grams, resulting in an average difference of + 96.32 grams. The predominant graft type was the right lobe excluding the middle hepatic vein, accounting for 82.00% (n = 387). Gender-based analysis showed males had slightly larger average CT-predicted graft volumes (719.79 mL) compared to females (710.48 mL). A strong positive correlation was observed between CT-estimated donor graft volume and the actual graft weight (Pearson's correlation coefficient = 0.74, P < 0.001). Conclusion: CT-derived preoperative liver volumes consistently overestimate the actual intraoperative graft weights in LDLT. Despite this disparity, CT remains a valuable tool in preoperative assessments, with the correlation between CT estimates and actual graft weights showcasing its reliability. Further advancements in CT techniques may minimize these discrepancies in future applications.