Over 500 obturator nerve blocks in the lithotomy position during transurethral resection of bladder tumor

INTRODUCTION AND AIM OF THE STUDY Spinal anesthesia for transurethral resection of bladder tumor (TURB) does not prevent unintended stimulation of the obturator nerve when electroresection is performed on the lateral wall of the bladder. It results in muscle contraction of the adductor muscles of the thigh, which may lead to perforation of bladder wall with the resectoscope loop. The aim of the study was to assess the efficacy and safety of obturator nerve block (ONB). METHODS This prospective study was conducted between 01/01/1999 and 12/31/2010 in the Department of General, Oncologic and Functional Urology, Medical University of Warsaw. In 431 patients undergoing TURB adductor spasms were observed. In these cases nerve stimulation and ONB with 2% lidocaine using thigh interadductor approach in the lithotomy position were performed. RESULTS The efficacy of 542 ONB was 94%. In 31 cases general anesthesia was necessary. There were two cases of urinary bladder perforation, but only one resulted from an insufficient nerve block. Both were managed conservatively. Neither hematomas nor neurological adverse events were observed. CONCLUSION The described method offers a high rate of efficacy and ensures optimal and safe conditions for the resection of a tumor located on the inferolateral wall of the urinary bladder. The risk of complication is low.