Risk factors for acute renal injury in living donor liver transplantation: evaluation of the RIFLE criteria.

Acute renal injury (ARI) is a serious complication after liver transplantation. This study investigated the usefulness of the RIFLE criteria in living donor liver transplantation (LDLT) and the prognostic impact of ARI after LDLT. We analyzed 200 consecutive adult LDLT patients, categorized as risk (R), injury (I), or failure (F), according to the RIFLE criteria. ARI occurred in 60.5% of patients: R-class, 23.5%; I-class, 21%; and F-class, 16%. Four patients in Group-A (normal renal function and R-class) and 26 patients in Group-B (severe ARI: I- and F-class) required renal replacement therapy (P < 0.001). Mild ARI did not affect postoperative prognosis regarding hospital mortality rate in Group A (3.2%), which was superior to that in Group B (15.8%; P = 0.0015). Fourteen patients in Group B developed chronic kidney disease (KDIGO stage 3/4). The 1-, 5- and 10-year survival rates were 96.7%, 90.6%, and 88.1% for Group A and 71.1%, 65.9%, and 59.3% for Group B, respectively (P < 0.0001). Multivariate analysis revealed risk factors for severe ARI as MELD ≥ 20 [odds ratio (OR) 2.9], small-for-size graft (GW/RBW <0.7%; OR 3.1), blood loss/body weight >55 ml/kg (OR 3.7), overexposure to calcineurin inhibitor (OR 2.5), and preoperative diabetes mellitus (OR 3.2). The RIFLE criteria offer a useful predictive tool after LDLT. Severe ARI, defined beyond class-I, could have negative prognostic impact in the acute and late postoperative phases. Perioperative treatment strategies should be designed and balanced based on the risk factors for the further improvement of transplant prognosis.