Efficacy of Transcutaneous Electrical Neural Stimulation and Tadalafil in Men With Erectile Dysfunction: A Randomized, Double-Blind, Bi-centric, Placebo- and Sham-Controlled Trial

Organic erectile failure is thought to be caused predominantly by neurogenic or vascular disorders. Venoocclusive dysfunction of the corpora cavernosa induces erectile dysfunction in 20-30% and appears clinically by premature erection loss.

The increased venous outflow from the corpora cavernosa can be illustrated as a so called 'venous leakage' by cavernosography being responsible for the therapeutical failure of intracavernously applied vasoactive substances. Cavernous smooth muscle pathology proven in some of the patients with venous leakage gave little hope to reconstructive surgery.

However, own examinations let assume that the etiology of 'venous leakage' is caused by endogenic and exogenic factors. Furthermore, reversible venous leakage was observed. Any therapeutic option of the veno-occlusive dysfunction showed disappointing results with a respective success rate of 20% in the long-term follow-up (surgical venous resection, percutaneous transpenile venous embolisms).

Finally the vacuum device or penile prosthetics are the only therapeutical option for the patients. Physiologically, bulbocavernous and ischiocavernous muscles increase the intracavernous pressure of the tumescent penis.

Regular pelvic floor exercise can be achieved by a physiotherapist which seems to be a time-consuming and expensive procedure, or an advantageous transcutaneous electrical stimulation which is the standard therapy for the treatment of posttraumatic atrophy of the striated muscular system.

Thus an external stimulator device has been developed to evaluate the therapeutical potency of striated muscle exercise in patients with erectile dysfunction. The present clinical study documents the first experiences with this EIS device and outlines its potency for the treatment of erectile dysfunction.

Study Overview

• Status: Completed
• Conditions: Erectile Dysfunction
• Intervention / Treatment: Drug: Placabo; Device: Sham stimulation; Device: Active TENS; Drug: Tadalafil 5 mg

• Study Type: Interventional
• Enrollment (Actual): 185
• Phase: Phase 4

Contacts and Locations

Study Locations

• Egypt
  • Menoufia
    • Shebin El-Kom, Menoufia, Egypt, 32511
      • Menoufia Faculty of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• clinical diagnosis of erectile dysfunction for at least 6 months and confirmed with penile color doppler ultrasound

Exclusion Criteria:

• Patients with history of cardiovascular disease, contraindication for phosphodiesterase type 5 inhibitor, implanted cardiac pacemakers or defibrillators, anatomically significant penile deformities, active skin lesions at the electrode placement sites or any untreated endocrinal disorder that could affect the erectile function

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Sham-placebo; This group will receive Sham stimulation along with Placebo similar to tadalafil	Drug: Placabo; Placebo resembling Tadalafil 5 mg oral tablet to be given once daily for 3 months; Device: Sham stimulation; Electrical stimulation using PhalliMax system which delivers low-frequency and low-intensity TENS currents. The stimulation is intended to treat cavernous smooth muscle insufficiency by stimulating penile tissue to enhance blood flow. Self-adhesive electrodes were systematically applied on the patient according to a specific anatomical configuration: 1) Electrodes were placed on the lateral sides of the penile shaft or in a circumferential manner below the glans and at the penile root to target the corpora cavernosa. 2) Electrodes were placed on the perineum and suprapubic region to target the pelvic floor muscles. Patients were instructed to perform the stimulation sessions daily for a duration of 30 minutes for 3 months. Pulse frequency is set to 30 Hz, width to 85 microseconds a and stimulation cycles included stimulation phase for 3 seconds then rest phase for 6 seconds. Here patients will receive only one stimulation cycle for 3 seconds then output decline to zero.
Other: Active-Placebo; This group will receive active stimulation along with Placebo similar to tadalafil	Drug: Placabo; Placebo resembling Tadalafil 5 mg oral tablet to be given once daily for 3 months; Device: Active TENS; Electrical stimulation using PhalliMax system which delivers low-frequency and low-intensity TENS currents. The stimulation is intended to treat cavernous smooth muscle insufficiency by stimulating penile tissue to enhance blood flow. Self-adhesive electrodes were systematically applied on the patient according to a specific anatomical configuration: 1) Electrodes were placed on the lateral sides of the penile shaft or in a circumferential manner below the glans and at the penile root to target the corpora cavernosa. 2) Electrodes were placed on the perineum and suprapubic region to target the pelvic floor muscles. Patients were instructed to perform the stimulation sessions daily for a duration of 30 minutes for 3 months. Pulse frequency is set to 30 Hz, width to 85 microseconds a and stimulation cycles included stimulation phase for 3 seconds then rest phase for 6 seconds.
Other: Sham-Tadalafil; This group will receive Sham stimulation along with tadalafil	Device: Sham stimulation; Electrical stimulation using PhalliMax system which delivers low-frequency and low-intensity TENS currents. The stimulation is intended to treat cavernous smooth muscle insufficiency by stimulating penile tissue to enhance blood flow. Self-adhesive electrodes were systematically applied on the patient according to a specific anatomical configuration: 1) Electrodes were placed on the lateral sides of the penile shaft or in a circumferential manner below the glans and at the penile root to target the corpora cavernosa. 2) Electrodes were placed on the perineum and suprapubic region to target the pelvic floor muscles. Patients were instructed to perform the stimulation sessions daily for a duration of 30 minutes for 3 months. Pulse frequency is set to 30 Hz, width to 85 microseconds a and stimulation cycles included stimulation phase for 3 seconds then rest phase for 6 seconds. Here patients will receive only one stimulation cycle for 3 seconds then output decline to zero.; Drug: Tadalafil 5 mg; Tadalafil 5 mg oral tablet to be given once daily for 3 months
Other: Active-Tadalafil; This group will receive active stimulation along with tadalafil	Device: Active TENS; Electrical stimulation using PhalliMax system which delivers low-frequency and low-intensity TENS currents. The stimulation is intended to treat cavernous smooth muscle insufficiency by stimulating penile tissue to enhance blood flow. Self-adhesive electrodes were systematically applied on the patient according to a specific anatomical configuration: 1) Electrodes were placed on the lateral sides of the penile shaft or in a circumferential manner below the glans and at the penile root to target the corpora cavernosa. 2) Electrodes were placed on the perineum and suprapubic region to target the pelvic floor muscles. Patients were instructed to perform the stimulation sessions daily for a duration of 30 minutes for 3 months. Pulse frequency is set to 30 Hz, width to 85 microseconds a and stimulation cycles included stimulation phase for 3 seconds then rest phase for 6 seconds.; Drug: Tadalafil 5 mg; Tadalafil 5 mg oral tablet to be given once daily for 3 months

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak systolic volume	Measured in cm/s to assess the arterial inflow via Penile Color Doppler Ultrasound	3 months
End diastolic volume	Measured in cm/s to evaluate the integrity of the veno-occlusive mechanism via Penile Color Doppler Ultrasound	3 months
Resistive index	equals peak systolic volume - end diastolic volume / peak systolic volume, all measured via Penile Color Doppler Ultrasound	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Erection Hardness Score	a Doppler-related erection grading system with the following Grades: Grade0: Lack of response, Grade1: Mild tumescence, Grade2: Tumescence insufficient for penetration, Grade3: Rigidity sufficient for penetration and Grade4: Complete rigidity. via Penile Color Doppler Ultrasound	3 months
IIEF-5 score	The IIEF-5 questionnaire (International Index of Erectile Function) is a 5-item, validated tool used to diagnose the presence and severity of erectile dysfunction (ED) where Scores range from 5-25, with lower scores indicating more severe dysfunction	3 months

Collaborators and Investigators

• Sponsor: Menoufia University
• Investigators: Study Director: Mohamed Alhefnawy, Urology Department, Benha University, Benha, Qalubia, Egypt; Principal Investigator: Islam Said, Urology Department, Benha University, Benha, Qalubia, Egypt

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2024
• Primary Completion (Actual): October 1, 2025
• Study Completion (Actual): March 1, 2026

Study Registration Dates

• First Submitted: May 3, 2026
• First Submitted That Met QC Criteria: May 3, 2026
• First Posted (Actual): May 7, 2026

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 3, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: TENS; Erectile Dysfunction; transcutaneous electrical neural stimulation; tadalafil
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Mental Disorders; Genital Diseases, Male; Male Urogenital Diseases; Sexual Dysfunction, Physiological; Sexual Dysfunctions, Psychological; Erectile Dysfunction; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Indoles; Indole Alkaloids; Heterocyclic Compounds, 3-Ring; Carbolines; Tadalafil
• Other Study ID Numbers: TENS and Tadalafil in ED

Drug and device information, study documents

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