NCT05897086

Brief Summary

Phalloplasty, a genitourinary surgery for transmasculine patients, reconstructs a neophallus using tissue transferred from other parts of the body to the groin. However, this technique fails to provide adequate sensation, causing regret and persistent dysphoria. Peripheral nerve regeneration is the greatest barrier to sensory recovery, given the slow rate of regrowth coupled with the negative effects of axonal degeneration. Topical application of polyethylene glycol (PEG) fuses severed axonal membranes, restoring the nerve's immediate ability to conduct electrical signals across the repair site. The investigators hypothesize that utilizing PEG in phalloplasties will significantly improve neophallus sensation and postoperative quality of life.

Trial Health

75
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
30

participants targeted

Target at P25-P50 for phase_2

Timeline
43mo left

Started Aug 2023

Longer than P75 for phase_2

Geographic Reach
1 country

1 active site

Status
enrolling by invitation

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress44%
Aug 2023Dec 2029

First Submitted

Initial submission to the registry

June 1, 2023

Completed
8 days until next milestone

First Posted

Study publicly available on registry

June 9, 2023

Completed
2 months until next milestone

Study Start

First participant enrolled

August 1, 2023

Completed
5.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 30, 2028

Expected
11 months until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2029

Last Updated

October 20, 2025

Status Verified

October 1, 2025

Enrollment Period

5.4 years

First QC Date

June 1, 2023

Last Update Submit

October 16, 2025

Conditions

Gender Dysphoria

Keywords

Phalloplasty

Outcome Measures

Primary Outcomes (1)

  • Medical Research Council Classification (MRCC)

    measures sensory recovery

    15 months

Secondary Outcomes (2)

  • Vanderbilt Mini-PROM for Gender-Affirming Surgery(VMP-G)

    15 months

  • Sexual Functioning and Sensation Questionnaire

    15 months

Study Arms (2)

Control (No Intervention)

NO INTERVENTION

For the control groups, epineural repair will be undertaken in the standard end-to-end fashion using interrupted nylon suture after irrigation of the wound with normal saline as deemed necessary by the operating surgeon.

Experimental

EXPERIMENTAL

For the experimental group, after obtaining hemostasis, prior to neurorrhaphy, the operative field will be irrigated with calcium-free Plasmalyte A® (Baxter: Deerfield, IL) throughout the neurorrhaphy. At this point, the nerves will be repaired using standard suture neurorrhaphy techniques. Subsequently, approximately 1 or 2 drops of 5mg/ml (0.5%) methylene blue in sterile water solution are applied to the trimmed nerve endings. Then, approximately 2 ccs of a 190 mM solution of 50% PEG 3.35 kD in sterile water will be irrigated onto the neurorrhaphy site and the surgeon will wait one minute prior to continuing. Following this, the repaired nerve will be irrigated with calcium-containing Lactated Ringers (Hospira; Lake Forest, IL).

Drug: Polyethylene Glycol 3350

Interventions

Polyethylene Glycol 3350DRUG

Topical irrigation with approximately 2 ccs of a 190 mM solution of 50% PEG 3.35 kD in sterile water

Experimental

Eligibility Criteria

Age18 Years+
Sexfemale(Gender-based eligibility)
Gender Eligibility DetailsTransmasculine
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • over the age of 18
  • preoperative diagnosis of gender dysphoria and present for planned radial forearm free flap phalloplasty
  • willing to comply with all aspects of treatment as well as the study evaluation schedule

You may not qualify if:

  • a known allergy to the study drug
  • a hematocrit of 54% or higher
  • a history of venous thromboembolism (VTE), peripheral phlebitis, stroke, or myocardial infarction within the last 6 months.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

Location

MeSH Terms

Conditions

Gender Dysphoria

Interventions

polyethylene glycol 3350

Condition Hierarchy (Ancestors)

Sexual Dysfunctions, PsychologicalMental Disorders

Study Officials

  • Wesley Thayer, MD

    Vanderbilt University Medical Center

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor of Plastic and Reconstructive Surgery

Study Record Dates

First Submitted

June 1, 2023

First Posted

June 9, 2023

Study Start

August 1, 2023

Primary Completion (Estimated)

December 30, 2028

Study Completion (Estimated)

December 1, 2029

Last Updated

October 20, 2025

Record last verified: 2025-10

Locations

US(1)