Predictors of renal function after open and robot-assisted partial nephrectomy: A propensity score-matched study.

Objective: To investigate parameters predicting short- and long-term renal function after open partial nephrectomy and robot-assisted partial nephrectomy.

Methods: Medical records of 896 patients who underwent open partial nephrectomy or robot-assisted partial nephrectomy from 2004 to 2017 at a single large-volume institution were retrospectively reviewed. Propensity score matching of open partial nephrectomy and robot-assisted partial nephrectomy group was carried out with a ratio of 1:1. Postoperative outcomes were compared, and multivariate logistic regression was carried out to identify the parameters influencing acute kidney injury and chronic kidney disease progression.

Results: No significant differences in preoperative characteristics were observed between the two study groups after matching. Robot-assisted partial nephrectomy was significantly associated with a longer warm ischemic time (P < 0.001) yet, estimated blood loss, positive surgical margin, rates of major postoperative complications and chronic kidney disease progression were significantly lower in the robot-assisted partial nephrectomy group (P < 0.001, 0.033, <0.001, <0.001, and 0.005, respectively). Multivariate analysis showed robot-assisted partial nephrectomy was more favorable than open partial nephrectomy in terms of preserving renal function. Patients with a higher baseline estimated glomerular filtration rate were significantly associated with a greater risk of acute kidney injury (odds ratio 1.036; 95% confidence interval 1.021-1.052; P < 0.001), but a decreased risk of chronic kidney disease progression (odds ratio 0.975; 95% confidence interval 0.955-0.994; P = 0.011). Other independent predictors of chronic kidney disease progression were warm ischemic time (P = 0.025), age (P = 0.035), body mass index (P = 0.041) and diabetes mellitus (P = 0.035).

Conclusions: Baseline estimated glomerular filtration rate, warm ischemic time and surgery type are independent predictors of both acute kidney injury and chronic kidney disease progression. Robot-assisted partial nephrectomy is more favorable than open partial nephrectomy for reducing estimated blood loss, positive surgical margin, major postoperative complications and renal function preservation.