Surgical details and renal function change after robot-assisted partial nephrectomy

Abstract

Objectives: To investigate whether differences in surgical details during robot-assisted partial nephrectomy impact postoperative renal function.

Methods: Patient, tumor and perioperative characteristics of 751 patients who underwent robot-assisted partial nephrectomy were analyzed with respect to the difference in ipsilateral glomerular filtration rate measured by diethylenetetramine pentaacetic acid renal scan. Detailed surgical methods defined for tumor excision (cutting vs splitting), hemostasis (suturing vs clipping) and renorrhaphy (continuous vs interrupted) were analyzed for early glomerular filtration rate decline and long-term recovery.

Results: The glomerular filtration rate of the entire cohort decreased by 9.8 mL/min/1.73 m2 (22%) at 3 months postoperatively, gradually increasing thereafter. The recovery slope was 1.7 mL/min/1.73 m2 /year during a median follow-up period of 23.0 months. Early glomerular filtration rate decline was more pronounced in the cutting group (23.5 vs 20.1%, P = 0.009). Clipping was associated with less glomerular filtration rate decline throughout the observation period, and the recovery slope was also significantly higher (2.7 vs 1.1 mL/min/1.73 m2 /year). In multivariate analysis, early decline was associated with age, preoperative glomerular filtration rate, parenchymal volume loss and ischemia >25 min. With respect to long-term recovery, suturing had the greatest adverse impact (β = -5.060, P < 0.0001, 95% confidence interval -7.709, -2.411) in addition to parenchymal volume reduction and early decline. In the propensity-matched cohort accounting for differences in tumor size and complexity, suturing was persistently associated with a significant glomerular filtration rate decline until >2 years after surgery.

Conclusions: Hemostatic sutures during robot-assisted partial nephrectomy might interfere with long-term renal function recovery irrespective of parameters that determine the initial function change. As the splitting method reduces the use of sutures, modifying these details might help preserve renal function.