Effect of ultrasound-guided proximal and distal approach for obturator nerve block in transurethral resection of bladder cancer under spinal anesthesia

Background: Ultrasound-guided proximal or distal approach for obturator nerve block is preformed to prevent adductor muscle spasm during transurethral resection of bladder tumors. The aim of the study was to compare the effectiveness of two different techniques in blocking the obturator nerve during transurethral resection of a bladder tumor. Methods: Fifty obturator nerve blocks were performed for transurethral bladder tumor resection and divided into two groups. One group received ultrasound-guided proximal obturator nerve block approach (proximal group), and the other group received ultrasound-guided distal obturator nerve block approach (distal group). Grade of adductor muscle spasm, the rate of clinical effectiveness, duration of block procedure, and complications were recorded. Patients with grade two adductor spasms were transferred to general anesthesia. Results: Two patients in the distal group and one in the proximal group were transferred to general anesthesia for severe adductor muscle spasms. No difference was found in clinical effectiveness rate of obturator nerve block between the two groups. differed insignificantly. The number of patients who had no adductor muscle spasms in the proximal group was significantly higher than that of the distal group. Vascular puncture was detected in two patients in the proximal group and one patient in the distil group. No other complications were observed. Conclusion: No difference was found for clinical effectiveness between the two groups. However, vascular puncture should receive more attention.