Obturator Nerve Block Transurethral Surgery for Bladder Cancer: Comparison of Inguinal and Intravesical Approaches: Prospective Randomized Trial

Aim: Transurethral resection of bladder tumors close to these areas may stimulate the obturator nerve, causing violent adductor contraction and possible inadvertent bladder perforation. To avoid this reaction, local anesthetic blockade of the obturator nerve as it passes through the obturator canal is effective in stopping adductor spasm during spinal anesthesia.

Methods: Forty-one patients undergoing (transurethral resection of bladder tumor) TUR-BT with spinal anesthesia who required (obturator nerve block) ONB were included in the study. After spinal anesthesia, ONB was performed with an inguinal approach (group 1) (n = 21) or an intravesical approach (group 2) (n = 20). In this study, we used 10 ml of 2 % lidocaine to perform the ONB.

Results: The mean age of patients was 60.8 ± 7.5 years. The groups were not different with regards to age, tumor localization and tumor size. There were two bladder perforations in group 1 and six perforations in group 2 (p = 0.130). However, the efficacy of ONB was significantly higher in inguinal approach group compared to intravesical approach group (p = 0.032).

Conclusion: Obturator nerve block plays an additive role on the quality of analgesia for bladder surgery. Our data suggests that identification of the obturator nerve with ultrasound is easy and the block can be assessed by observing avoidance of bladder spasm.