Preventing the Obturator Nerve Reflex

Bladder Injury Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01547637
• Other study ID #: PRAMS039186EP
• Status: Completed
• Phase: N/A
• Start date: May 2012
• Est. completion date: August 2017

Study information

• Verified date: May 2018
• Source: Milton S. Hershey Medical Center
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: August 2017
• Est. primary completion date: August 2017
• Accepts healthy volunteers: No
• Gender: All
• Age group: 35 Years and older

Eligibility

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).

Related Conditions & MeSH terms

• Bladder Injury

Intervention

Procedure:
• Obturator nerve block
Peripheral obturator nerve block using 10 ml of 2% lidocaine
• Obturator nerve block
Ultrasound guided peripheral obturator nerve block

Locations

Country	Name	City	State
United States	Penn State Milton S. Hershey Medical Center	Hershey	Pennsylvania

Sponsors (1)

Lead Sponsor	Collaborator
Milton S. Hershey Medical Center

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Nerve conduction velocity	Neuromonitoring technician will measure and record obturator nerve conduction velocity in pre-defined time intervals after performance of obturator nerve block.	1 day