RIRS is equally efficient in patients with different BMI scores.

The objective of the study was to ascertain whether flexible ureteroscopy with holmium laser lithotripsy and/or extraction of stone fragments is as effective in obese patients as in non-obese patients. The patients were divided into four groups (group 1: normal weight = 79 procedures, group 2: overweight = 123 procedures, group 3: obese = 87 procedures, and group 4: morbidly obese = 20 procedures) according to BMI cohorts. Patient charts were retrospectively reviewed and relevant data collected. A total of 309 operations were included in the present study. The overall mean ± SD (range) age was 41 ± 12 years (18-82), BMI 29 ± 6 kg/m(2) (18-52), operative time 64 ± 29 min (20-200), hospital stay 25 ± 11 h (4-168), stone number 3 ± 2 (1-15), stone burden 21 ± 14 mm (4-98), and internal stenting time 26 ± 8 days (2-60). Mean stone size was 10 ± 6, 9 ± 5, 11 ± 8, and 11 ± 8 mm for groups 1 through 4, respectively. There were no differences among groups regarding patients and stone characteristics, and perioperative parameters including patient age, operative time, hospital stay, and complications. Overall SFRs were similar between groups (81, 87, 87.4, and 85%, respectively; χ(2)=3.304, p=0.770) as were the complication rates (12-16%). Our contemporary Retrograde Intrarenal Surgery (RIRS) series showed that operative times, hospital stays, ancillary equipment use (internal stent, basket, etc.), SFRs, and complication rates were independent of BMI. Therefore, RIRS can be performed as efficiently and efficaciously in obese patients as in non-obese patients.