Conditions: Vasculogenic Erectile Dysfunction
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 24
Healthy volunteers: yes

Brief summary:
Evidence has been arising that Botulinum toxin injections can relax smooth muscles fibers in the treatment of obesity and hyperactive bladder. Would a similar effect on cavernosal smooth muscles help in the treatment of resistant erectile dysfunction not responding to medical and injection therapy, thus avoiding surgical treatment options.

The treatment group will be injected intracavernously with 50 units of BTX-A. The control group, 12 patients, will be injected with a normal saline injection.

Detailed description:
24 males with will be included in the study. All will be subjected for full history taking, general and genital examination. Penile duplex will be performed to assess a vascular etiology before the treatment and 2 weeks later. The patients will be randomized into a treatment group (12 patients) and a control group (12 patients).

All patients will sign an informed consent. The treatment group will be injected IC with a trimix solution (20 ug alprostadil + 1 mg phentolamine + 30 mg papaverine) for color Doppler assessment, followed, next day by 50 units of BTX-A. The control group, 12 patients, will be injected with the trimix solution during penile color Doppler assessment followed next day with a normal saline injection. The erection hardness score (EHS) will be assessed during the Doppler exam.

Procedure: At least 1 day after the penile color Doppler test, the patient is placed in the supine position flaccid and stretched penile length and girth would be measured from tip of the penis to the pubic bone will be done. A rubber band will be applied to the base of the penis. The skin will be prepped with alcohol swabs followed by the IC injection of 50 units of BTX-A. Direct pressure will be applied for 2 minutes. The rubber band will be removed after 15 minutes.

Patients and controls will fill the Sexual Health Inventory for men (SHIM) questionnaire and answer the the Sexual Encounter Profile questions 1 and 2 (SEP 2 \& SEP 3), and the global assessment question (GAQ) before and 4 weeks after treatment.

The rational for selecting the minimum 2-weeks waiting period is to give a chance for the BTX-A to reach its maximum effect. Possible Risks include pain and prolonged erections.

Arms:
arm 1: The treatment group will be injected intracavernously with a trimix solution for colour Doppler assessment, followed, on a separate day by 50 units of Botulinum toxin (BTX) A. arm 2: The control group, 12 patients, will be injected with a trimix solution (20 ug alprostadil + 1 mg phentolamine + 30 mg papaverine) during penile colour Doppler assessment followed on a separate day with a normal saline injection.

Interventions: intervention 1: Botulinum Toxin Type A intervention 2: Normal Saline
Intervention descriptions: intervention 1: The treatment group will be injected intracavernously with a trimix solution (20 ug alprostadil + 1 mg phentolamine + 30 mg papaverine) for colour Doppler assessment, followed next day by 50 units of BTX-A. intervention 2: The control group, 12 patients, will be injected with a trimix solution during penile colour Doppler assessment followed next day with a normal saline injection.

Protocol document: