[Flexible ureterorenoscopy in obese patients: results from a large monocenter cohort]

Objective: To analyze results and morbidity after flexible ureterorenoscopy (fURS) in patients with a body mass index (BMI)>30 kg/m² and to compare with results obtained in a large cohort of non-obese patients.

Methods: We conducted a retrospective monocenter study including all fURS for urinary lithiasis performed in our institution between January 2004 and December 2010. During the study period, 497 procedures were performed. Twenty-three had to be excluded because of missing data on BMI. Thus, a total of 474 procedures were included in the final analysis, 93 for obese patients (OP) and 381 for non-obese patients (NOP). Characteristics of the patients, stones and procedures were analyzed. Success was defined as clear imaging (completely stone-free) on renal tomography and ultrasonography.

Results: Mean BMI was 33.5 ± 0.3 in OP vs 23.9 ± 0.1 kg/m² in NOP (P<0.0001). Mean stone size, location, and composition were not significantly different between groups. Technical aspects (operative time, ureteral dilatation, access sheath, monobloc extraction) were also similar in OP and NOP. The immediate (63.5% for OP vs 66.1% in NOP, P=0.62) and follow-up (65.1% for OP vs 71% in NOP, P=0.26) stone-free rate were not significantly different between the groups. For stone size<1cm, SFR raised to 77% in OP vs 83% in NOP (P=0.28). The rate of minor complications Clavien II was similar in OP (7.5%) and NOP (12%). No major complication (Clavien III or IV) was observed.

Conclusion: fURS is a safe and efficient option for the management of urinary lithiasis in obese patients.