A prospective, observational study to assess the feasibility and safety of supine percutaneous nephrolithotomy under regional anesthesia for obese patients with a body mass index ≥30.

INTRODUCTION

Besides being a risk factor for urolithiasis, obesity is a challenge in the treatment of urolithiasis from the perspective of both the surgeon and the anesthetist. In this study, we tried to assess the feasibility and safety of supine percutaneous nephrolithotomy (PCNL) under regional anesthesia in obese patients with a body mass index (BMI) ≥30.

METHODS

This was a prospective observational study and included 51 obese patients (BMI ≥30 kg/m2) with renal stones planned for PCNL. All patients underwent supine PCNL under regional anesthesia with the standard technique. A decision for totally tubeless or a tubeless PCNL was made at the end of the procedure and the intraoperative and postoperative data were recorded. All patients underwent computed tomography (CT) imaging at 1 month after surgery to assess the stone-free status and the need for additional treatment.

RESULTS

The mean age of the patients was 53.2 ± 8.09 years, and the mean BMI was 34.4 ± 2.369 kg/m2. The mean operative time was 73.3 ± 26.2 min, the mean hospital stay was 58.3 ± 22.1 h, and the mean postoperative Visual Analog Score (VAS) for pain was 3.8 ± 1.4. The stone-free rate was 68.6% on the follow-up CT performed after 1 month, and 31.4% of the patients had significant residual fragments which required re-treatment either by retrograde intrarenal surgery (RIRS) in 19.6% (either as primary RIRS for the residual calculi in one patient [1.9%] or as RIRS for post shock wave lithotripsy (SWL) or alkalinization failure in 9 patients), SWL in 21.6%, or urine alkalinization in 7.8%.

CONCLUSION

Supine PCNL under regional anesthesia, in this subgroup of obese patients, was found to be feasible and safe with satisfactory stone-free rates and minimal postoperative pain.