KangDuo vs. da Vinci robot-assisted pyeloplasty: a propensity score-matched analysis of surgical outcomes.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) is commonly treated by robot-assisted pyeloplasty (RAP). While the da Vinci (DV) robotic system is widely established, the KangDuo (KD) system has emerged as an alternative platform. This study aimed to compare the clinical outcomes and safety of KD-RAP with DV-RAP. METHODS: A total of 263 consecutive patients who underwent DV-RAP and 74 consecutive patients who underwent KD-RAP were included in the study. Propensity score matching (PSM) was performed to balance baseline characteristics, resulting in 66 patients in each group. Surgical outcomes were compared between the two groups. Stratified analysis by robotic system version, inverse probability of treatment weighting (IPTW) sensitivity analysis, and learning curve analysis were additionally performed. RESULTS: After PSM, no significant differences in baseline characteristics were observed. The median operative time was significantly longer in the KD-RAP group {DV-RAP: 132 [interquartile range (IQR): 107-153] vs. KD-RAP: 149 [IQR: 132-181] minutes, effect size [95% confidence interval (CI)]: 19.5 [2.5-36.5], P=0.02}, as well as postoperative length of stay (PLOS) {DV-RAP: 4 [IQR: 4-5] vs. KD-RAP: 5 [IQR: 4-7] days, effect size [95% CI]: 1 [0.5-1.5], P<0.001}. Stratified analysis and IPTW sensitivity analysis were consistent with PSM results. Learning curve analysis showed no significant correlation between case number and operative time in KD-SR-1000 (KD 1.0) system (Spearman's ρ=0.134, P=0.35), while a modest, albeit non-significant, trend toward improvement was observed in KD-SR-2000 (KD 2.0) system (Spearman's ρ=-0.374, P=0.08). No significant differences were found in estimated blood loss (P=0.82), surgical success rate (DV-RAP: 93.9% vs. KD-RAP: 90.9%, P=0.75), or estimated glomerular filtration rate (eGFR) at final follow-up (P=0.09). Complication rates were comparable (DV-RAP: 1 vs. KD-RAP: 3, P=0.63), with all complications classified as Clavien-Dindo grade II. No major complications or equipment-related adverse events occurred. CONCLUSIONS: KD-RAP showed comparable safety and efficacy to DV-RAP. Although KD-RAP had longer operative time and PLOS, both systems achieved similar success rates and low complication rates, supporting the feasibility of the KD system as an alternative to the DV system in the management of UPJO.