Low intensity shock waves (LISW) have been proven in animal studies to induce local growth of new blood vessels. The investigators hypothesized that LISW therapy could improve the symptoms of patients with erectile dysfunction resulting from a problem of blood supply (damage that can occur after radical prostatectomy in addition to neural damage or solely) that do not respond to oral therapy (PDE-5 inhibitors).

Inclusion Criteria:

• Prior prostatectomy surgery
• ED of more than 6 months
• Rigidity score < 3 during PDE5i therapy
• Non- hormonal, neurological or psychological pathology Stable heterosexual relationship for more than 3 months

Exclusion Criteria:

• Any unstable medical, psychiatric, spinal cord injury and penile anatomical abnormalities
• Clinically significant chronic hematological disease
• Anti-androgens, oral or injectable androgens
• Radiotherapy in pelvic region