Introduction
Bladder cancer is the sixth most common cancer in men in the United
States (1). Transurethral resection of bladder tumour (TUR-BT) is an
initial diagnostic and therapeutic procedure for non-muscle invasive
bladder cancer (NMIBC). The most common complications related to tumour
resection include minor bleeding and irritative symptoms in the early
postoperative period. The major complications, including uncontrolled
haematuria and bladder perforation, may occur in approximately 5% of
cases (2). The obturator nerve is located near the inferolateral bladder
wall, and it arises from the anterior rami of the second, third and
fourth lumbar nerves, descends through the psoas major and emerges from
the psoas major medial border. The nerve then crosses into the pelvis at
the level of the sacroiliac joint. At this point, it courses close to
the wall of the bladder (3). TUR-BT of bladder tumours localized close
to the lateral side of the bladder may stimulate the obturator nerve and
trigger the adductor contraction approximately the rate of 20%, causing
possible inadvertent bladder perforation or an incomplete resection due
to hindrance of the tumour resection (4). Spinal anaesthesia combined
with obturator nerve blockade in the obturator canal may be effective in
preventing adductor spasm (5). Various strategies are recommended to
prevent undesirable adductor contractions due to obturator nerve
stimulation. For instance, the incidence of obturator nerve stimulation
can be reduced by attention to technical strategies, decreasing the
intensity of energy, avoiding overdistention of the bladder, and using
anaesthetic paralysis or giving general anaesthesia during the resection
of lateral wall localized tumours to decrease an obturator reflex
response (4,6,7). Meta-analyses comparing bipolar and monopolar TUR-BT
have reported no statistically significant differences between bipolar
and monopolar TUR-BT in terms of obturator reflex and bladder
perforation rates (8,9).
Most of the bladder cancers (70–75%) were NMIBC during the initial
diagnosis. Tumour recurrence is more common for NMIBC. Nearly 30% of
patients have tumour recurrence within the first 3 months of having
TUR-BT, and 50% of patients have a recurrent tumour at the 1-year
follow-up (10). The major causes of recurrent tumour have been reported
to be residual tumour tissue due to incomplete resection or inability to
obtain adequate muscle tissue during TUR-BT (11). The obturator reflex
that occurs during the TUR-BT may increase the risk of incomplete
resection of the tumour, inability to sample the muscle tissue or tumour
dissemination via bladder perforation.
In this study, we aimed to investigate the effect of obturator nerve
blockade on oncological outcomes in patients undergoing TUR-BT for
lateral wall localized NMIBC.