Korean J Anesthesiol.  2011 Aug;61(2):143-147. 10.4097/kjae.2011.61.2.143.

Comparison of the success rate of inguinal approach with classical pubic approach for obturator nerve block in patients undergoing TURB

• Jo YY
• Choi E
• Kil HK

• KMID: 1766709
• DOI: http://doi.org/10.4097/kjae.2011.61.2.143

Abstract

BACKGROUND
During transurethral resection of bladder tumors (TURB) under spinal anesthesia, electrical resection of the lateral wall mass may cause violent adductor contraction and possible inadvertent bladder perforation. Therefore, obturator nerve block (ONB) is mandatory after spinal anesthesia to avoid adductor muscle contraction. We compared the success rate and efficacy of an inguinal approach, to a pubic approach for ONB.
METHODS
One hundred and two patients who required ONB undergoing TURB with spinal anesthesia were included in this study. After spinal anesthesia, ONB was performed with an inguinal approach (Group I, n = 51) or pubic approach (Group P, n = 51) using a nerve stimulator. In the pubic approach, a needle was inserted at a point 1.5 cm lateral and 1.5 cm inferior to the pubic tubercle. For the inguinal approach, a needle was inserted at the midpoint of the femoral artery and the inner margin of the adductor longus muscle 0.5 cm below the inguinal crease. If the adductor contracture had not occurred by the 3rd attempt, it was defined as a failed block. Puncture frequency, success rate, anatomical characteristics, and the presence of adductor muscle contraction during operation were evaluated.
RESULTS
The success rate of ONB was higher in group I compared to group P (96.1% vs. 84.0%, P = 0.046) and the frequency of needle attempts was lower in group I than in group P (1.8 +/- 0.9 vs. 1.3 +/- 0.6, P = 0.01).
CONCLUSIONS
The inguinal approach for ONB appears to be technically easier and offers certain anatomical advantages when compared to the pubic approach.

Keyword

Inguinal approach; Obturator nerve block; TURB

MeSH Terms

Anesthesia, Spinal
Contracts
Contracture
Femoral Artery
Humans
Muscle Contraction
Muscles
Needles
Obturator Nerve
Punctures
Urinary Bladder
Urinary Bladder Neoplasms