MedPath

Pudendal Nerve Mapping Towards Improved Neuromodulation for Urinary Retention

Not Applicable
Completed
Conditions
Urinary Retention
Underactive Bladder
Interventions
Device: Participants received a Neurostimulator, which was used to map the pudendal nerve
Registration Number
NCT04236596
Lead Sponsor
University of Michigan
Brief Summary

This study is to map the pudendal nerve. In this study the researchers will examine subjects who are already receiving an implanted stimulator at their pudendal nerve as part of their normal clinical care.

Detailed Description

The pudendal nerve goes to the urethra, anus, and other areas of the pelvic floor. Electrical stimulation of this nerve can help with bladder problems and pelvic pain. Researchers do not understand how the nerve anatomy is different between people. Successfully mapping the pudendal nerve may help improve the medical care for future patients with bladder problems, pelvic pain, bowel problems, and sexual problems.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
22
Inclusion Criteria
  • Clinically referred as having bladder problems that have not responded to conservative treatment. Normal clinical care includes referral to implant of Medtronic Interstim neurostimulator at the pudendal nerve. Fully eligible to receive an Interstim implant.
  • Adult (18 or older), capable of providing own informed consent and communicating clearly with research team
  • Capable of speaking, reading, and understanding English, as all study questionnaires are standardized assessments only available in English
  • Capable of attending all experimental sessions (Visit 1: pre-stage-1 imaging, Visit 2: stage-1 surgery, Visit 3: CT after stage-2 surgery, Visit 3: cystometrogram test)

Exclusion

  • Implanted materials that prohibit magnetic imaging
  • Any medical problems that prevent an individual from laying flat in an MRI or CT scanner, are are claustrophobic.
  • Areflexive or atonic bladder
  • Pregnant or planning to become pregnant. If a woman of child-bearing potential wishes to participate in this study, they will be pre-screened with a test to detect pregnancy.
  • Diagnosed neurogenic bladder, pudendal nerve damage, lower motor dysfunction, or other conditions that would affect the neural circuits involved in micturition.
  • Unwilling to allow de-identified data to be stored for future use or shared with other researchers.
Read More
Exclusion Criteria

Not provided

Read More

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Study participantsParticipants received a Neurostimulator, which was used to map the pudendal nerveStudy participants received an implanted neurostimulator at their pudendal nerve as part of normal clinical care. This was not an intervention study as clinical care was not modified based on study participation. Participants consented to undergo in the research study steps towards mapping of the pudendal nerve.
Primary Outcome Measures
NameTimeMethod
Number of Participants With Evoked Bladder Contractions of at Least 20 Centimeters of Water (cmH2O) During the Stage-4 TestVisit 4, approximately 10 weeks after consent

The primary outcome measure in this study was an evoked bladder contraction of at least 20 centimeters of water (cmH2O) during the cystometrogram. These bladder contractions were evoked by applying nerve stimulation to the pudendal nerve through testing of the participant's implanted stimulator. Measure reflects number of participants who experienced an evoked bladder contraction of at least 20 centimeters of water during nerve stimulation.

Secondary Outcome Measures
NameTimeMethod
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Simulated Model StimulationApproximately one year and four months after consent

Selectivity is the degree to which part of a nerve could be stimulated without stimulating other nerve parts. For each participant who had successful MRI and CT images, a computational model was created to simulate electrical stimulation of axons distributed in two primary pudendal fascicles: perineal and rectal. The SI of stimulation does not indicate a positive or negative result in this outcome; rather, it shows the relative potential for activating just a single nerve fascicle. The negative/positive designation identifies the regional nerve activation, with -1 representing only perineal fascicle activation, +1 representing only rectal activation, and 0 indicating equal activation of both fascicles.

Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Participant StimulationVisit 2: Stage-1 (approximately 3 weeks after consent)

Selectivity refers to the degree in which a nerve could be stimulated without stimulating other nerves. SI was calculated for each sensor recording from locations innervated by distal pudendal nerve branches during the visit-2 implant procedure. This includes pressure sensors in the urethra innervated by the perineal nerve and anal electromyography (EMG) innervated by the ischeal rectal nerve. The SI calculation used here is on a scale of 0 to 1, with 0 indicating no response at all from the nerve. The closer the number is to 1, the more selective the nerve stimulated.

Measurement of Effect of Pudendal Nerve Stimulation on Urethral Leak Point Pressure During the Stage-4 TestVisit 4, approximately 10 weeks after consent

A secondary outcome measure was a goal to examine the effect of selective pudendal nerve stimulation on urethral leak point pressure during the cystometrogram.

Trial Locations

Locations (1)

University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

© Copyright 2025. All Rights Reserved by MedPath