Clinical trial · Interventional
Comparison of Nerve Stimulating Approach and Interfascial Injection Approach During Sono-guided Obturator Nerve Block
Comparison of Nerve Stimulating Approach and Interfascial Injection Approach During Sono-guided Obturator Nerve Block in Transurethral Resection of Bladder Tumors Under Spinal Anesthesia
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
Transurethral resection of bladder tumor (TURB) has been essential treatment for bladder tumours. Direct electrical stimulation of an obturator nerve during the TURB procedures can trigger an inadvertent adductor muscle spasm, which can cause a serious complication like bladder perforation. General anesthesia with muscle relaxants for TURB does not guarantee a prevention of the adductor muscle spasm. Spinal anesthesia with selective obturator nerve block (ONB) can be an alternative anesthesia for TURB, but adductor spasm can also be induced because of incomplete ONB. Recently, ultrasound guidance with nerve stimulator has been used to enhance the safety, efficacy and shortening the onset time of ONB. Some papers describe that comparable ONB can be done using ultrasound only without nerve stimulator, in which there is a principle that obturator nerve runs along a given pathway. Basically, obturator nerve is divided into two branches after exiting the obturator canal. The anterior branch is located in the fascial planes among adductor longus, adductor brevis and pectineus muscles, and the posterior branch is located between the adductor brevis and adductor magnus muscles at the inguinal area. But it has been known that there are many branching patterns of obturator nerve and high anatomic variability in the inguinal area in a cadaver study. And subdivisions of obturator nerve in the inguinal area have been described. Therefore, this study was conducted to investigate the success rate of ultrasound-guided obturator nerve block with interfascial injection approach group (US-IFI; experimental group) was comparable to ultrasound-guided obturator nerve block with nerve stimulating approach group (US-NS; control group) in TURB under spinal anesthesia. And we also evaluated adductor muscle twitching patterns at the inguinal region when the ONB was performed.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Bladder Cancer | Malignant Bladder Neoplasm | CURATED_EXACT | 0.92 |
Interventions
Interventions (2)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| nerve stimulator (stimuplex HNS12) | Device | — | UNRESOLVED |
| ultrasound | Device | — | UNRESOLVED |
Design
Arms and outcomes
Arms (2)
- type
- EXPERIMENTAL
- label
- US-IFI group
- description
- ultrasound-guided obturator nerve block with interfascial injection approach group (US-IFI; experimental group) The stimulating needle without nerve stimulator advanced via an ultrasound to position the needle tip on the fascia between adductor longus and adductor brevis muscles. 10mL of local anesthetics were slowly injected. The needle was reinserted to position the needle tip on the fascia between adductor brevis and adductor magnus muscles, another 5mL of LA was injected. After that, the needle was reinserted to the same spots attached with nerve stimulator at 1.0 mA. If adductor muscle twitching was shown, another 5mL of LA was injected, and it was documented as 'fail'.
- interventionNames
- Device: nerve stimulator (stimuplex HNS12)
- Device: ultrasound
- type
- ACTIVE_COMPARATOR
- label
- US-NS group
- description
- ultrasound-guided obturator nerve block with nerve stimulating approach group (US-NS; control group) The stimulating needle attached to a nerve stimulator advanced via an ultrasound to position the needle tip on the fascia between adductor longus and adductor brevis muscles. The nerve stimulator was then turned on, and the stimulation current started at 0.5 mA. If adductor muscle twitching was observed on the sonogram even at the stimulation current 0.3mA, 10mL of local anesthetics were slowly injected. The needle was reinserted to position the needle tip on the fascia between adductor brevis and adductor magnus muscles. The stimulation current started at 0.5 mA. If adductor muscle twitching was visualized on the sonogram even at 0.3mA, another 5mL of LA was injected.
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 20 Years
- Maximum age
- 80 Years
Show eligibility criteria text
Inclusion Criteria: * all patients anticipating transurethral resection of bladder tumors with American Society of Anesthesiologists physical status(ASA) I or II Exclusion Criteria: * patients with diabetes or peripheral neuropathy; motor or sensory deficits in the lower extremities, ASA greater than III, coagulation disorders, anticoagulant medication, known allergy to local anesthetics, contraindications for spinal anesthesia (infection at injection site, severe scoliosis or fusion operation), uncooperative patients and patients' refusal
References
Publications (1)
- BACKGROUNDAnagnostopoulou S, Kostopanagiotou G, Paraskeuopoulos T, Chantzi C, Lolis E, Saranteas T. Anatomic variations of the obturator nerve in the inguinal region: implications in conventional and ultrasound regional anesthesia techniques. Reg Anesth Pain Med. 2009 Jan-Feb;34(1):33-9. doi: 10.1097/AAP.0b013e3181933b51. PMID 19258986