Background : The expanding donor pool includes marginal donors with steatosis, small-for-size grafts, and elderly donors. This study aimed to investigate liver volumetric regeneration after living donor right hepatectomy(LDRH) in elderly and younger donors

Methods : From March 2012 to December 2022, 38 elderly(≥ 55years) and 291 younger donors (<30years) underwent LDRH. Donors without preoperative liver fibroscan or postoperative follow-up CT after three months were excluded. Propensity score matching resulted in a final cohort of 55 younger and 30 elderly donors. Remnant liver volume was assessed via CT within one-year after surgery. Clinical characteristics and liver volumetric regeneration was compared between two groups. Binary logistic regression was used to analyze risk factors for poor liver regeneration.

Results : The mean age was 58.0 and 24.0 years for elderly and younger donor, respectively. Preoperative factors were similar. Rapid liver regeneration occurred within the first months (median 465.9mL, 77.8% of initial total liver volume(iTLV)), but elderly donors showed significantly lower liver regeneration rates than younger age donors throughout all time points (around 1 month: 83.5 vs. 75.5%, P=0.001; 3 months: 89.9 vs. 79.2%, P<0.001; 6 months: 94.7 vs.86.2%,P=0.001). Multivariate logistic regression analysis identified old age and low preoperative phosphate level (<3.5mg/dL) as risk factors for liver regeneration below 80% of iTLV.

Conclusions : After LDRH, liver regeneration within one year reaches over 95% of the original volume in young donors but is less, at approximately 86% of the original volume, in elderly donors. Therefore, more conservative criteria for the remnant liver volume need in elderly donors compared to younger donors.