Navigating the challenge: does obesity compromise outcomes in single-port robot-assisted pyeloplasty?

To evaluate the impact of body mass index (BMI) on early perioperative and functional outcomes in adult patients undergoing single-port robot-assisted pyeloplasty (S-RAP) for ureteropelvic junction obstruction (UPJO). We retrospectively reviewed adult patients who underwent S-RAP for unilateral UPJO between 2019 and 2025. Patients were classified into three groups according to World Health Organization BMI categories: normal weight (BMI < 25 kg/m²), overweight (25 ≤ BMI < 30 kg/m²), and obese (BMI ≥ 30 kg/m²). Baseline characteristics, perioperative outcomes, postoperative pain, opioid consumption, complications, surgical success, and renal function changes were compared among the groups. Renal function recovery was assessed using the change in estimated glomerular filtration rate (ΔeGFR). A total of 45 patients were included, comprising 14 normal-weight, 17 overweight, and 14 obese patients. Baseline characteristics were comparable among the three groups. No significant differences were observed in operative time, estimated blood loss, length of hospital stay, catheter removal time, drainage tube removal time, postoperative pain scores, opioid consumption, overall complications, Clavien-Dindo grade ≥ 3 complications, imaging relief, clinical symptom relief, or surgical success. However, ΔeGFR differed significantly among the groups, with the greatest improvement observed in obese patients, followed by overweight patients, whereas normal-weight patients showed a slight decline. In conclusion, increased BMI was not associated with inferior early perioperative outcomes, complication rates, pain recovery, or surgical success after S-RAP in selected adult patients with UPJO. S-RAP appears to be a feasible and effective option for obese adults when performed by experienced surgeons.