Preoperative Computed Tomography Volumetry and Graft Weight Estimation in Adult Living Donor Liver Transplantation

Abstract

Background:Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim:To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods:Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results:Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r2=0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 - 0.99 (p<0.0001). Conclusion:The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82.

The Correlation between the CT Liver Volume and the Actual Weight of the Resected Cirrhotic Liver in Transplantation Patients

“…Previous studies reported a significant correlation between the predicted liver volume and the actual volume, or the actual weight of the liver. 16,20 Unfortunately, most of the data were derived from healthy liver grafts of living donors. There was a study on CT volumetry in patients who underwent partial liver resection; however, this study did not take the presence of liver cirrhosis into account.…”

“…However, several studies suggested that this number might not be appropriate, and alternative methodsranging from a different conversion factor to a more complex formula-were proposed. 16,19,20,25 Nevertheless, these suggestions came from studying normal livers and did not account for the presence of liver cirrhosis. In the current study, we proposed a formula that can accurately predict the weight of the resected cirrhotic liver (R-squared =0.914).…”

Reliable Estimation of Preoperative Graft Volume in Living Donor Liver Transplantation

“…These include various computer programs, 12 decreasing CT slice thickness and different equations and formulas using patient's age, height, gender, body weight, BSA, and even maximal portal vein diameters. 8,13 It is however recognized that universal applicability of such proposed methods is questionable due to several factors. 14 Although CT scan with manual volumetry is gold standard for assessment of liver volumes, it overestimated the graft weight in most of the cases of our study.…”

“…They have estimated that this factor is close to 0.82 in their studies. 8,9 We decided to analyse the data of our institute to review the methodology and local applicability of the graft weight/volume estimation techniques and attempt to formulate our own protocols which would lead to a more realistic graft weight/volume calculation.…”

Twenty years after: from Milan criteria to a “blended” approach

“…For example, the implementation of the laparoscopic hepatic resection (13), the more liberal use of living-donor LT, even in Western countries (14), or finally the growing use of perfusion machines with the intent to improve the use of marginal grafts (15) all represent new opportunities for the physicians involved in the management of HCC patients waiting for LT.…”