Purpose: To compare blind and nerve stimulation guided transurethral obturator nerve block (ONB) in transurethral resection of bladder tumor (TURBT) to prevent obturator reflex.
Patients and methods: One hundred and twelve patients with lateral bladder wall tumors and at high risk for general anesthesia were categorized randomly in three groups. In the first group (34 patients), after spinal analgesia was administered, the exact site of the obturator nerve was determined by nerve stimulation and 15 mL of lidocaine HCl 2% was injected around the nerve. In the second group (31 patients), we determined the obturator nerve using nerve stimulation (like the first group), then 20 mL of saline was injected. In the third group (47 patients), the obturator nerve was determined based on anatomic landmarks and blocked subsequently. Leg jerking was reported and compared in the three groups.
Results: The median ages in the three groups were 55.4, 59.4, 57.8 years in the first, second, and third groups, respectively. Male/female ratios were 79.5% in the first, 80.7% in the second, and 80.9% in the third group (P=0.986). Leg jerking was reported in 5.8%, 34%, and 6.3% of patients in the first, second, and third groups, respectively (P=0.0001). ONB took 6.7 minutes in the first, 6.1 minutes in the second, and 5.2 minutes in the third group, on average. There was no report of adverse effects of lidocaine HCl in this study.
Conclusion: Transvesical ONB is a safe and effective method of ONB before TURBT. This method is feasible by urologists and promising even without nerve stimulation and only by anatomic landmarks.