The present study evaluates the efficacy and safety of repetitive treatments of Low Intensity Extracorporeal Shock Wave Treatment (LI-ESWT) using Aries ED device in men with mild-moderate and severe vasculogenic ED, who have previously responded to oral PDE5-Is, and completed 6 or 12 sessions of LI-ESWT with Aries device during the last 6 month.

This is an extension, 2 parallel arms, clinical trial of a previous study in which patients were PDE5I users/responders and were randomized to receive either one or two shockwave treatment sessions per week for a total of 6 weeks, without treatment interval. After completing the 6-month follow up of the first trial , ED patients will be screened, in order to identify if the IIEF ED domain is still abnormal (<26). Afterwards, the 2 groups of the first study will follow the 2 different treatment protocols (once vs twice per week). All patients will receive 6 treatment sessions with Aries, with the same energy level. First treatment session will take place between days 0-28 from the day of the 6-month follow up. All patients will agree and sign a new Informed Consent Form. Therefore, patients who took 6 sessions once a week (Group A in the previous trial) will be switched to take 6 sessions twice a week in 3 weeks, and those already treated with 12 sessions twice a week (Group B in the previous trial) will be treated with 6 sessions once a week.

Study visits and duration

Baseline - Visit: the basic work-up will take place, including medical and sexual history, as well as lab tests, if indicated by medical history. The IIEF-ED domain will be measured, as well as the Sexual Encounter Profile (SEP) for the last 4-week period with at least 4 attempts for intercourse (without PDE5i use). The study criteria will be checked and if patients are eligible (IIEF-ED domain <26), they will receive their first repetitive treatment, either on the same day as the 6-month follow up of the previous study or within maximum 4 weeks.

Treatment Visits: In all treatment visits, patients will receive active LI-ESWT treatment, according to the study protocol. Group A will receive treatment twice per week for three weeks and Group B will receive treatment once per week for six weeks. Interval between 2 treatments will be 7+2days for Group B and 3+1 day for Group A. Adverse events and changes in concomitant medication will be recorded. PDE5i intake is prohibited throughout the treatment period.At visit 6 penile ultrasonography will be conducted in order to check for potential adverse events related to the treatment.

Follow-up visit 1 - 3 (4, 12 and 24 weeks post treatment): the SEP diaries will be returned and the IIEF-ED domain will be completed for the 4 weeks prior to the aforementioned timepoints, during which no PDE5i intake is allowed. The document of the visit (protocol compliance, adverse events) will be completed. At week 12, triplex ultrasonography will be performed by the standard protocol.

Inclusion Criteria:

1. Consent to participate
2. Age >18
3. Presence of vasculogenic erectile dysfunction for at least 6 months
4. Positive response to PDE5i
5. Patients who completed the 6 months follow-up of a previous study including 6 or 12 sessions of LI-ESWT with Aries device and still have an abnormal IIEF ED domain (< 26)
6. Abnormal penile triplex-based hemodynamic parameters (peak flow velocity <35cm/sec)
7. Stable heterosexual relationship for more than 3 months
8. Sexually active and agree to suspend all ED therapy for the duration of study

Exclusion Criteria:

1. Any cause of ED other than vascular related
2. Previous radiation therapy to pelvis
3. History of radical prostatectomy
4. Clinically significant chronic haematological disease
5. Cardiovascular conditions that prevent sexual activity
6. Peyronie's Disease or penile curvature
7. History of heart attack, stroke or any life- threatening arrhythmia within the prior 6 month
8. Anti-androgens oral or injectables androgens
9. Untreated Hypogonadism as demonstrated by abnormal testosterone levels
10. Malignancy within the past 5 years
11. Any unstable medical, psychiatric condition or spinal cord injury
12. Anatomical or neurological abnormalities in the treatment area
13. Use of any treatment for ED within 7 days of screening ( oral medications, vacuum devices, constrictive devices, injections or urethral suppositories)
14. Known allergy to ultrasound gel