Propensity-score matched analysis comparing robot-assisted with laparoscopic partial nephrectomy

Abstract

Objectives: To compare the peri-operative and early renal functional outcomes of robot-assisted partial nephrectomy (RAPN) and laparoscopic partial nephrectomy (LPN) for kidney tumours.

Materials and methods: A total of 237 patients fulfilling the selection criteria were included, of whom 146 and 91 patients were treated with LPN and RAPN, respectively. To adjust for potential baseline confounders, propensity-score matching was performed. A favourable outcome was defined as a warm ischaemia time (WIT) of ≤20 min, negative surgical margins, no surgical conversion, no Clavien ≥3 complications and no postoperative chronic kidney disease (CKD) upstaging. Descriptive statistics and multivariable logistic regression analyses were performed before and after propensity-score matching.

Results: Within the propensity-score-matched cohort, the RAPN group was associated with significantly lower estimated blood loss (EBL; 156 vs 198 mL, mean difference [MD] = -42; P = 0.025), a shorter WIT (22.8 vs 31 min, MD = -8.2; P < 0.001) and a higher proportion of malignant lesions (88.4 vs 67.5%; odds ratio [OR]: 2.6; 95% confidence interval [CI]: 1.2-5.67; P = 0.023). With regard to early renal functional outcomes, the mean last estimated glomerular filtration rate was 95.8 and 89.4 mL/min per 1.73 m(2) (MD = 6.4; P = 0.01), with a mean ± sd percentage change of -4.8 ± 17.9 and -12.2 ± 16.6 (MD = 7.4; P = 0.018) in the RAPN and LPN groups, respectively. The intra-operative complication rate was significantly lower in the RAPN group (1.3 vs 11.7%; OR 0.1, 95% CI 0.01-0.81; P = 0.018). On multivariable analysis, surgical approach (RAPN vs LPN, OR 5.457, 95% CI 2.075-14.346; P = 0.001), Charlson Comorbidity Index (OR 0.223; 95% CI 0.062-0.811; P = 0.023), diameter-axial-polar score (OR 0.488, 95% CI 0.329-0.723; P < 0.001) and preoperative CKD stage (OR 3.189, 95% CI 1.204-8.446; P = 0.020) were found to be independent predictors of obtaining a favourable outcome.

Conclusions: After adjusting for potential treatment selection biases, RAPN was found to be superior to LPN for peri-operative outcomes (EBL, WIT and intra-operative complications) and early renal functional preservation.

Keywords: complications; functional outcomes; laparoscopic partial nephrectomy; nephron-sparing surgery; robot-assisted partial nephrectomy.