Pudendal Nerve Mapping Towards Improved Neuromodulation for Urinary Retention

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.

Study Overview

• Status: Completed
• Conditions: Urinary Retention; Underactive Bladder
• Intervention / Treatment: Device: Participants received a Neurostimulator, which was used to map the pudendal nerve

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.

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Study participants; Study 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.	Device: Participants received a Neurostimulator, which was used to map the pudendal nerve; Participants in study received neurostimulator at their pudendal nerve as part of their normal clinical care. This neurostimulator was used to map the nerve.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Evoked Bladder Contractions of at Least 20 Centimeters of Water (cmH2O) During the Stage-4 Test	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.	Visit 4, approximately 10 weeks after consent

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Participant Stimulation	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.	Visit 2: Stage-1 (approximately 3 weeks after consent)
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Simulated Model Stimulation	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.	Approximately one year and four months after consent
Measurement of Effect of Pudendal Nerve Stimulation on Urethral Leak Point Pressure During the Stage-4 Test	A secondary outcome measure was a goal to examine the effect of selective pudendal nerve stimulation on urethral leak point pressure during the cystometrogram.	Visit 4, approximately 10 weeks after consent

Collaborators and Investigators

• Sponsor: University of Michigan
• Collaborators: National Institutes of Health (NIH)
• Investigators: Principal Investigator: Tim Bruns, Ph.D., University of Michigan; Principal Investigator: Priyanka Gupta, M.D., University of Michigan

Study record dates

Study Major Dates

• Study Start (Actual): September 14, 2020
• Primary Completion (Actual): June 8, 2023
• Study Completion (Actual): June 8, 2023

Study Registration Dates

• First Submitted: January 13, 2020
• First Submitted That Met QC Criteria: January 20, 2020
• First Posted (Actual): January 22, 2020

Study Record Updates

• Last Update Posted (Actual): August 20, 2024
• Last Update Submitted That Met QC Criteria: July 26, 2024
• Last Verified: July 1, 2024

More Information

Terms related to this study

• Keywords: pudendal nerve mapping
• Additional Relevant MeSH Terms: Urologic Diseases; Urinary Bladder Diseases; Lower Urinary Tract Symptoms; Urological Manifestations; Urination Disorders; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Urinary Retention; Urinary Bladder, Underactive
• Other Study ID Numbers: HUM00165005; OT2OD028191 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All de-identified IPD collected during the trial will be available.
• IPD Sharing Time Frame: Will be available starting twelve months following publication of study findings.
• IPD Sharing Access Criteria: Anyone who wishes to access the data.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes