Preoperative proteinuria is associated with increased rates of acute kidney injury after partial nephrectomy

Vol. 45 (5): 932-940, September – October, 2019

doi: 10.1590/S1677-5538.IBJU.2018.0776

ORIGINAL ARTICLE

Önder Kara 1, 2, Matthew J. Maurice 1, Pascal Mouracade 1, Ercan Malkoc 1, Julien Dagenais 1, Mustafa Çapraz 3, Jaya S. Chavali 1, Merve Yazici Kara 4, Jihad H. Kaouk 1

1 Department of Urology, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA; 2 Kocaeli University, Medical School, Kocaeli, Turkey; 3 Amasya University, Medical School, Amasya, Turkey; 4 Kocaeli Derince Training and Research Hospital, Kocaeli, Turkey

ABSTRACT

Purpose: We investigated the association between preoperative proteinuria and early postoperative renal function after robotic partial nephrectomy (RPN).

Patients and Methods: We retrospectively reviewed 1121 consecutive RPN cases at a single academic center from 2006 to 2016. Patients without pre-existing CKD (eGFR≥60 mL/min/1.73m²) who had a urinalysis within 1-month prior to RPN were included. The cohort was categorized by the presence or absence of preoperative proteinuria (trace or greater (≥1+) urine dipstick), and groups were compared in terms of clinical and func­tional outcomes. The incidence of acute kidney injury (AKI) was assessed using RIFLE criteria. Univariate and multivariable models were used to identify factors associated with postoperative AKI.

Results: Of 947 patients, 97 (10.5%) had preoperative proteinuria. Characteristics as­sociated with preoperative proteinuria included non-white race (p<0.01), preoperative diabetes (p<0.01) and hypertension (HTN) (p<0.01), higher ASA (p<0.01), higher BMI (p<0.01), and higher Charlson score (p<0.01). The incidence of AKI was higher in pa­tients with preoperative proteinuria (10.3% vs. 4.6%, p=0.01). The median eGFR pres­ervation measured within one month after surgery was lower (83.6% vs. 91%, p=0.04) in those with proteinuria; however, there were no significant differences by 3 months after surgery or last follow-up visit. Independent predictors of AKI were high BMI (p<0.01), longer ischemia time (p<0.01), and preoperative proteinuria (p=0.04).

Conclusion: Preoperative proteinuria by urine dipstick is an independent predictor of postoperative AKI after RPN. This test may be used to identify patients, especially those without overt CKD, who are at increased risk for developing AKI after RPN.

Keywords: Kidney Neoplasms; Proteinuria; Acute Kidney Injury

[Full Text]