Analysis of Outcome in Recipients with Different Graft-Recipient-Weight-Ratio (GRWR) Post Adult to Adult Living Donor Liver Transplant (LDLTx)
Authors: Maher Marolla , AbdElRazek Ahmed , Talaat Mahmoud , ElAal Amr Ahmed Abd 
Published: August 2023

Abstract

Background
The problem of graft size is one of the critical factors limiting the expansion of adultto-adult living donor liver transplantation (LDLT). Graft-to-recipient weight ratio (GRWR) &gt; 0.8% is perceived as the critical graft size to meet the metabolic demand of the recipient. Small-for-size graft (SFSG) is the graft with GRWR &lt; 0.8 and when its unable to meet the recipients metabolic demands, small-for-size syndrome (SFSS) occurs which is a life-threatening condition with rapidly progressive liver failure. This lower limit of GRWR (0.8%) has been challenged over the last decade perhaps due to better understanding of the pathophysiology, coupled with technical refinements, particularly related to venous outflow reconstruction.

Aim of Work
Our aim was to analyse the different outcomes of patients undergoing Living donor liver transplantation using grafts with GRWR ≤ 0.8% with those &gt;0.8% to evaluate the factors that affect the post-operative outcome and the overall one year Graft survival.

Methods
This is a retrospective cohort study on 100 adult patients with ESLD or HCC (mean age 54.16 ± 10.53 years old) who underwent adult LDLT in the period between 2018 and 2020 and follow up the patients for one year post transplant, Patients were divided into two groups, patients who received Graft with GRWR ≤ 0.8 (N = 22 patients with lower limit of GRWR = 0.58 and there is 7 patients with GRWR ≤ 0.7) and those with GRWR &gt;0.8 (N = 78 patients). We compared the the Donor factors, preoperative patient factors, intraoperative factors, development of small for size syndrome and graft survival in patients received small-for-size grafts (GRWR ≤ 0.8) with patients received GRWR &lt;0.8.

Results
We retrospectively evaluated the donor factors, recipient factors and operative factors through the medical records. Small-for-size syndrome (SFSS) occurred in 2 of 22 patients (9.1%) in patients with GRWR ≤ 0.8 and in 1 of 78 patients (1.3%) in patients with GRWR &gt;0.8 which was statistically insignificant between two groups. There was No significant difference in the Donor age, Preoperative MELD, CHILD, Portal hypertension, cold and warm ischemia, operative time, presence of PVT and HCC in patients who received GRWR ≤ 0.8 and patients with GRWR &gt;0.8. the mean overall survival for all the studied cases was found 43.35 months and the overall survival at 6 months and 1 year was 96.0% but there was statistically significant increase in the overall survival of cases with GRWR &gt;0.8 than those with GRWR ≤ 0.8 with p-value = 0.009, as the overall 6 months and 1 year survival for patients with GRWR &gt;0.8 was 98% and 98 % compared to 86 % and 86 % in thoses with GRWR ≤ 0.8

Conclusion
There is no difference in the outcome in form of development of Small for size syndrome when we use Grafts with GRWR &gt;0.8 or with GRWR ≤ 0.8, However the venous Outflow of SFSG (GRWR &lt; 0.8) is very critical to maintain good graft function in the recipient.