Delayed remnant kidney function recovery is less observed in living donors who receive an analgesic, intrathecal morphine block in laparoscopic nephrectomy for kidney transplantation: a propensity score-matched analysis

BACKGROUND: This study analyzed remnant kidney function recovery in living donors after laparoscopic nephrectomy to establish a risk stratification model for delayed recovery and further investigated clinically modifiable factors. PATIENTS AND METHODS: This retrospective study included 366 adult living donors who underwent elective donation surgery between January 2017 and November 2019 at our hospital. ITMB was included as an analgesic component in the living donor strategy for early postoperative pain relief from November 2018 to November 2019 (n = 116). Kidney function was quantified based on the estimated glomerular filtration rate (eGFR), and delayed functional recovery of remnant kidney was defined as eGFR < 60 mL/min/1.73 m(2) on postoperative day (POD) 1 (n = 240). RESULTS: Multivariable analyses revealed that lower risk for development of eGFR < 60 mL/min/1.73 m(2) on POD 1 was associated with ITMB, female sex, younger age, and higher amount of hourly fluid infusion (area under the receiver operating characteristic curve = 0.783; 95% confidence interval = 0.734–0.832; p < 0.001). Propensity score (PS)-matching analyses showed that prevalence rates of eGFR < 60 mL/min/1.73 m(2) on PODs 1 and 7 were higher in the non-ITMB group than in the ITMB group. ITMB adjusted for PS was significantly associated with lower risk for development of eGFR < 60 mL/min/1.73 m(2) on POD 1 in PS-matched living donors. No living donors exhibited severe remnant kidney dysfunction and/or required renal replacement therapy at POD 7. CONCLUSIONS: We found an association between the analgesic impact of ITMB and better functional recovery of remnant kidney in living kidney donors. In addition, we propose a stratification model that predicts delayed functional recovery of remnant kidney in living donors: male sex, older age, non-ITMB, and lower hourly fluid infusion rate.