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Preventing the Obturator Nerve Reflex

Preventing the Obturator Nerve Reflex: A Comparison of Ultrasound Guided Obturator Nerve Block and Classic Anatomic Block Technique.

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01547637
Enrollment
40
Registered
2012-03-08
Start date
2012-05-31
Completion date
2017-08-31
Last updated
2018-05-31

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bladder Injury

Keywords

Obturator nerve block, Regional anesthesia, TURBT

Brief summary

The key objective of this study is to compare success rates of ultrasound guided obturator nerve block and anatomic landmark guided obturator nerve block as determined by neuromonitoring endpoints and surgeon observations.

Detailed description

Transurethral resection of bladder tumor (TURBT) is a urologic surgery used in the treatment of non-muscle invasive bladder cancer. A potential complication of this procedure is bladder rupture or injury secondary to adductor muscle contraction from obturator nerve stimulation. This risk is increased in resection of lateral wall tumors, as electrosurgical resection of these lesions is more likely to inadvertently stimulate the obturator nerve. There are several mechanisms for preventing the obturator reflex. Pharmacologic paralysis can reliably inhibit thigh adduction. However, TURBT is often a short procedure that is not amendable to intermediate duration neuromuscular blocking medications. The use of succinylcholine is another option but is limited by its short duration of action which may not be adequate for the time needed to resect the tumor. Additionally, many patients have contraindications to the use of succinylcholine. Spinal anesthesia does not reliably prevent the obturator reflex. Regional anesthesia is another potential treatment modality to prevent the obturator reflex during TURBT. Motor blockade of the obturator nerve will prevent this adduction in the event of inadvertent nerve stimulation. Peripheral blockade of the obturator nerve can be combined with either general or spinal anesthesia. Historically, obturator nerve block (ONB) has been considered a technically challenging procedure. Recently, however, successful ultrasound guided ONB techniques have been reported. To the best of our knowledge there has been no study to date comparing the effectiveness of ONB achieved by anatomic landmarks (with nerve stimulation) versus ultrasound guided ONB (with nerve stimulation) at preventing the obturator reflex during TURBT surgery. The key objective of this study is to compare success rates of ultrasound guided obturator nerve block and anatomic guided obturator nerve block as determined by neuromonitoring endpoints and surgeon observations.

Interventions

Peripheral obturator nerve block using 10 ml of 2% lidocaine

Sponsors

Milton S. Hershey Medical Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
35 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Patients undergoing TURBT for lateral wall bladder tumors at risk for electrical stimulation as determined by the attending surgeon.

Exclusion criteria

* Pre-existing obturator nerve injury * Thigh adductor muscle weakness * Neuropathy * Local anesthetic allergy * Infection at the site of injection * Abnormal coagulation studies * use of neuromuscular blocking medications (if deemed necessary by attending anesthesiologist caring for the patient).

Design outcomes

Primary

MeasureTime frameDescription
Nerve conduction velocity1 dayNeuromonitoring technician will measure and record obturator nerve conduction velocity in pre-defined time intervals after performance of obturator nerve block.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026