A prospective randomized controlled trial comparing subpectineal and interfascial obturator nerve block techniques in preventing adductor muscle spasm during transurethral resection of bladder tumors
In brief
Nerve blocks avoided rescue anesthesia in 87% to 93% of bladder tumor resections
In a randomized trial of 60 patients, severe adductor spasms requiring rescue general anesthesia did not occur in 87% of patients receiving a subpectineal block and 93% receiving an interfascial block. The difference was not statistically significant, and the small study cannot establish that one approach is better; both appear viable options for this procedure.
- Journal
- BMC anesthesiology (Q1)
- Published
- 22 July 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Yavuz Saygılı, Halil C Köse, Selin G Köse, Ömer T Akkaya
- PMID
- 42894134
- DOI
- 10.1186/s12871-026-04091-5
Why clinicians should know about it
- Picked for Urology (top studies of the week, 8 November 2026): Ultrasound-guided ONB techniques, high success rates
Abstract
BACKGROUND: Obturator nerve block (ONB) is commonly used to prevent adductor muscle spasm during transurethral resection of bladder tumors (TURBT) involving lateral wall lesions. This study aimed to compare the clinical effectiveness and safety of ultrasound-guided subpectineal (proximal) and interfascial (distal) ONB techniques, utilizing an anatomically tailored dosing regimen adapted to the targeted fascial compartments. METHODS: This prospective randomized controlled trial included 60 patients scheduled for elective TURBT under spinal anesthesia. Patients were randomly allocated into two equal groups: subpectineal ONB (Group I, n = 30), which received a single 10 mL bolus of 0.375% bupivacaine into the single subpectineal plane, and interfascial ONB (Group II, n = 30), which received a total of 20 mL of 0.375% bupivacaine split into two separate 10 mL injections for the two distinct interfascial planes. Intraoperative adductor muscle spasm was evaluated by a blinded surgeon using a 4-grade scale (Grades I-IV). The primary outcome was the block success rate, defined as the absence of severe spasm (Grade IV) requiring rescue general anesthesia. RESULTS: Baseline demographic characteristics and the number of needle insertions were similar between the groups. No vascular puncture, hematoma, or bladder perforation occurred. The descriptive block success rate was high in both groups, reaching 86.7% (95% Confidence interval: 74.6% to 98.8%) in Group I and 93.3% (95% Confidence Interval: 84.4% to 100%) in Group II, with no statistically significant difference observed (p = 0.671). CONCLUSIONS: Both ultrasound-guided ONB techniques demonstrate high descriptive clinical success rates when utilizing an anatomically tailored dosing regimen. Although the non-significant p-value must be interpreted with caution due to sample size limitations, both approaches provide viable and effective options for preventing severe adductor muscle spasm during lateral wall TURBT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT07481123 (retrospectively registered on 02 March 2026).
Abstract as published, via PubMed.
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