Preoperative estimation of the liver graft weight in adult right lobe living donor liver transplantation using maximal portal vein diameters

Abstract

An accurate preoperative estimate of the graft weight is vital to avoid small-for-size syndrome in the recipient and ensure donor safety after adult living donor liver transplantation (LDLT). Here we describe a simple method for estimating the graft volume (GV) that uses the maximal right portal vein diameter (RPVD) and the maximal left portal vein diameter (LPVD). Between June 2004 and December 2009, 175 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. The GV was determined with 3 estimation methods: (1) the radiological graft volume (RGV) estimated by computed tomography (CT) volumetry; (2) the computed tomography-calculated graft volume (CGV-CT), which was obtained by the multiplication of the standard liver volume (SLV) by the RGV percentage with respect to the total liver volume derived from CT; and (3) the portal vein diameter ratio-calculated graft volume (CGV-PVDR), which was obtained by the multiplication of the SLV by the portal vein diameter ratio [PVDR; ie, PVDR ¼ RPVD 2 /(RPVD 2 þ LPVD 2 )]. These values were compared to the actual graft weight (AGW), which was measured intraoperatively. The mean AGW was 633.63 6 107.51 g, whereas the mean RGV, CGV-CT, and CGV-PVDR values were 747.83 6 138.59, 698.21 6 94.81, and 685.20 6 90.88 cm 3 , respectively. All 3 estimation methods tended to overestimate the AGW (P < 0.001). The actual graft-to-recipient body weight ratio (GRWR) was 1.00% 6 0.19%, and the GRWRs calculated on the basis of the RGV, CGV-CT, and CGV-PVDR values were 1.19% 6 0.25%, 1.11% 6 0.22%, and 1.09% 6 0.21%, respectively. Overall, the CGV-PVDR values better correlated with the AGW and GRWR values according to Lin's concordance correlation coefficient and the Landis and Kock benchmark. In conclusion, the PVDR method is a simple estimation method that accurately predicts GVs and GRWRs in adult LDLT.

Variability of standard liver volume estimation versus software-assisted total liver volume measurement

“…In our review, we found that currently there are 16 published formulas for estimating SLV in the worldwide literature4‐18 (see Table 1). More recently, several authors have combined portal vein diameters and SLV estimates to calculate the hemiliver volume for split liver transplantation or LDLT 21, 22. In our clinical experience, SAIP volumetric studies using CT scans (ie, software‐assisted CT scans) have been very accurate in predicting graft sizes with predetermined resection planes in comparison with actual graft volumes in living liver donors 23.…”

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

“…In our review, were found at least 11 different 2 , 3 , 4 , 6 , 7 , 8 , 9 , 11 , 12 , 17 , 18 , 21 , 22 , and sometimes conflicting, mathematical formulas aiming to predict graft size. Some of these methods do not use the computed tomography volumetry, but body surface area, and the diameter of the portal vein and/or their branches.…”

Left-sided grafts for living-donor liver transplantation and split grafts for deceased-donor liver transplantation: Their impact on long-term survival

“…The minimum graft size required for LDLT to provide adequate hepatic function has been reported to be a SLV of 40% or GRWR of 0.8 [2]. For insufficient graft volume, APOLT was established to increase liver volume after LT [19], although there are some limitations in the choice of recipients.…”

“…A small-for-size graft is defined as a graft to recipient weight ratio (GRWR) less than 0.8 or a ratio of graft weight against standard liver volume (SLV) less than 40% [1,2], and these grafts result in a high mortality and morbidity.…”