Trifecta outcomes of robotic partial nephrectomy in obese patients: A comparison of body mass index <25, 25 to <30, and ≥30.

Objective: We analyzed robotic partial nephrectomy (RPN) outcomes in obese patients based on body mass index (BMI) and trifecta achievement.

Methods: We retrospectively reviewed 296 patients who underwent RPN at Kansai Medical University Hospital between 2014 and 2022. The preoperative clinical data and perioperative outcomes were evaluated. Trifecta achievement (negative surgical margin, no major complications, and no acute kidney injury on postoperative day three) and its relationship to three BMI groups (<25, 25 to <30, and ≥30) were the primary outcome. The correlation between factors in achieving trifecta and BMI was evaluated. Univariate and multivariate analyses assessed variables for achieving the trifecta with logistic regression analysis. C-statistics quantitatively evaluated the prediction accuracy.

Results: Among 296 patients, 264 (89.2%) achieved trifecta (BMI categories were <25 [89.9%], 25 to <30 [89.4%], and ≥30 [82.6%]). There was no significant BMI-related difference (p = 0.566). Intraoperative blood loss increased with the BMI (p = 0.034). Multivariate analyses showed preoperative aspects and dimensions used for anatomic (PADUA) score independently predicted trifecta failure (odds ratio 1.71; 95% confidence interval 1.32-2.20; p < 0.001). The C-statistics of the PADUA score increased with increasing BMI.

Conclusions: Higher BMI patients had more intraoperative blood loss during RPN. However, RPN remains safe and has acceptable quality and functional outcomes. Since patients with high PADUA scores combined with a high BMI may be at risk of trifecta failure, this should be explained before RPN.