Trial Outcomes & Findings for Pudendal Nerve Mapping Towards Improved Neuromodulation for Urinary Retention (NCT NCT04236596)

Last Updated: 2024-08-20

Results Overview

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.

Recruitment status

COMPLETED

Study phase

Target enrollment

22 participants

Primary outcome timeframe

Visit 4, approximately 10 weeks after consent

Results posted on

2024-08-20

Participant Flow

Participant milestones

Participant milestones
Measure	Study Participants Study participants are receiving an implanted neurostimulator at their pudendal nerve and consent to undergo study procedures.
Overall Study STARTED	22
Overall Study COMPLETED	14
Overall Study NOT COMPLETED	8

Reasons for withdrawal

Reasons for withdrawal
Measure	Study Participants Study participants are receiving an implanted neurostimulator at their pudendal nerve and consent to undergo study procedures.
Overall Study Withdrawal by Subject	1
Overall Study Participants did not retain implant for entire trial	3
Overall Study Participants did not receive implant at all	4

Baseline Characteristics

Pudendal Nerve Mapping Towards Improved Neuromodulation for Urinary Retention

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Study Participants n=22 Participants Study participants received an implanted neurostimulator at their pudendal nerve and consented to participate in study activities.
Age, Continuous	54.37 years STANDARD_DEVIATION 13.15 • n=5 Participants
Sex: Female, Male Female	18 Participants n=5 Participants
Sex: Female, Male Male	4 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	20 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	1 Participants n=5 Participants
Race (NIH/OMB) White	21 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	22 Participants n=5 Participants

PRIMARY outcome

Timeframe: Visit 4, approximately 10 weeks after consent

Population: Due to scheduling conflicts and participant attrition, only 10 participants completed this part of the study. All were women.

Outcome measures

Outcome measures
Measure	Participants Undergoing Cystometrogram n=10 Participants This group includes participants who underwent the cystometrogram procedure.
Number of Participants With Evoked Bladder Contractions of at Least 20 Centimeters of Water (cmH2O) During the Stage-4 Test	0 Participants

SECONDARY outcome

Timeframe: Visit 2: Stage-1 (approximately 3 weeks after consent)

Population: Data was collected from 16 participants who received the implant.

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.

Outcome measures

Outcome measures
Measure	Participants Undergoing Cystometrogram n=16 Participants This group includes participants who underwent the cystometrogram procedure.
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Participant Stimulation Perineal nerve	0.57 index Standard Deviation 0.29
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Participant Stimulation Rectal nerve	0.90 index Standard Deviation 0.22

SECONDARY outcome

Timeframe: Approximately one year and four months after consent

Population: Computational models were created for 10 participants who received the implant. The model data was segregated into three groups: participants with selectivity indices positive (\>0) for all four contacts (rectal only), negative (\<0) for all four contacts (perineal only), and mixed (both \>0 and \<0). Each group has the same potential range for SI values: -1 to +1. Values in the Outcome Measure Data Table are calculations across all lead contacts and participants per group.

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.

Outcome measures

Outcome measures
Measure	Participants Undergoing Cystometrogram n=10 Participants This group includes participants who underwent the cystometrogram procedure.
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Simulated Model Stimulation Rectal dominant	0.577 index Standard Deviation 0.193
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Simulated Model Stimulation Perineal dominant	-0.533 index Standard Deviation 0.284
Selectivity Index (SI) for Selective Stimulation of Pudendal Nerve Branches for Simulated Model Stimulation Mixed	0.288 index Standard Deviation 0.666

SECONDARY outcome

Timeframe: Visit 4, approximately 10 weeks after consent

Population: Selective pudendal nerve stimulation was not performed during the cystometrogram sessions due to time limitations within experimental sessions, so there is no data available. "Selectivity" could not be accomplished as it was described in the protocol for this nerve bundle.

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

Outcome measures

Outcome data not reported

Adverse Events

Study Participants

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Timothy Bruns

University of Michigan

Phone: (734) 647-8727

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place