Background & Objectives: Trans Urethral Resection of Bladder Tumour (TURBT) is a procedure in which bladder tumors can be removed from the bladder wall and the procedure is performed completely with a resectoscope that is inserted through the urethra into the bladder. The obturator nerve, which arises from the ventral divisions of the second, third, and fourth lumbar nerves, passes in close proximity to the infero lateral bladder wall, bladder neck and lateral prostatic urethra.

During transurethral resection of bladder tumours (TURBT) under spinal anaesthesia, electrical resection of the lateral wall mass may cause violent adductor contraction and possible inadvertent bladder perforation, vessel laceration, incomplete tumour resection, and obturator hematomas. Therefore, Obturator Nerve Block (ONB) is mandatory after spinal anaesthesia for TURBT.

Our study was undertaken to compare Success Rate* and Ease of Block** of Inguinal and Classic approach for obturator nerve block in patients undergoing transurethral resection of bladder tumour under spinal anaesthesia.

*Number of cases in which Obturator reflex or Adductor spasm is prevented after administration of block

**Number of attempts required to elicit Adductor muscle contraction using peripheral nerve stimulator and to administer local anaesthetic.

Methodology: 80 patients aged 40-90 years belonging to ASA PS – I&II of both sexes undergoing Transurethral Resection of Bladder Tumour under Spinal anesthesia were included in our study.   Patients satisfying the inclusion criteria were allotted into 2 groups of 40 each.

Group 1: Patients received obturator nerve block via classic approach

Group 2: Patients received obturator nerve block via inguinal approach

Results: In our study, we found that the success rate of obturator nerve block by the inguinal approach was higher with less incidence of Adductor spasm (7.5%) compared to the classic group (25%) and the ease of block was higher for the inguinal group in which the  mean number of puncture attempts was less (1.85 ± 0.834) compared to classic group (2.45 ± 0.932)

Conclusion: From our study we conclude that the Inguinal approach for obturator nerve block appeared to be an easily performable block with a high success rate compared to the Classic approach.

Keywords: Obturator nerve block, Transurethral resection, Obturator reflex, Adductor spasm.

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Dr Hari Dev J.J

Senior Resident, Department of Anesthesiology, Govt. Medical College, Kottayam