Low-intensity shockwave therapy (LISWT) has recently emerged as a promising method in Patients Who Do Not Respond to Phosphodiesterase Type 5 Inhibitors in the treatment of erectile dysfunction (ED).Erectile dysfunction (ED) is a medical entity that is highly prevalent in men older than 50 years whose history of vascular risk factors (VRFs) has been a common denominator in the origin of this symptom.It is very common in India too.India is the Impotence capital of the world about 50percent people above 40 yrs suffer it.Many studies have stressed the status of ED as a potential indicator of cardiovascular disease, although other clinical trials have found a high incidence of ED in men with VRFs such as metabolic syndrome, diabetes, and hypertension.

                       Since 1998, the phosphodiesterase type 5 inhibitor (PDE5i) has introduced a change in the treatment paradigm for patients with ED because approximately 60% of patients can recover their erectile function and lead a satisfactory sex life.Despite the effectiveness of PDE5i in the treatment of ED, 40% to 50% of patients—depending on the etiology of the dysfunction—do not respond to this drug therapy, even after optimization approaches such as treatment combinations have been implemented.

For some years, low-intensity shockwave therapy (LISWT) has been implemented for the treatment of ED and to optimize the response to PDE5i.A shockwave is a wave of abrupt pressure (vibration movement) produced by an object that travels faster than the speed of sound (<10 ns) producing external pressure differences and increased temperature.

since year 1988,different intensities have been used therapeutically in medicine. High-intensity shockwaves (pressure = 450 bar) have been implemented in the treatment of urolithiasis, medium-intensity shockwaves (pressure = 200 bar) in the treatment of arthralgia, tendinitis, and bursitis, and more recently LISWT (pressure = 80 bar) in the treatment of ED.

     Young and Dyson12 discovered that therapeutic ultrasound encourages angiogenesis by enhancing the expression of vascular endothelial growth factor. Nurzynska et al13 reported that shockwaves have a positive influence on the proliferation and differentiation of cardiomyocytes, smooth muscle, and endothelial cell precursors, with a more obvious effect in cells from a normal heart than from a pathologic heart.

        After these initial reports, LISWT was implemented in the treatment of chronic myocardial ischemia and diabetic foot ulcers, among other applications.The idea of applying LISWT to the penis stemmed from a study with animals that proved that the energy of shockwaves applied to the myocardium of pigs ameliorates ischemia-induced myocardial dysfunction.By extrapolating these findings to ED, it was presumed that shockwaves applied to the penis might increase blood flow and improve endothelial function through the stimulation of angiogenesis in the corpus cavernosum.

               The mechanism of action is still not completely elucidated. However, low-intensity energy has been shown to induce the production of a physiologically significant amount of non-enzymatic nitric oxide and activate intracellular cascade pathways that trigger the release of angiogenic factors.In this way, shockwaves produce mechanic stress and microtrauma at the cellular level, thus generating a series of biological cascades that favor the release of angiogenic factors leading to neovascularization.

           Interestingly, the results recently published by Assaly-Kaddoum et al21 showed that LISWT significantly improved erectile function in Goto-Kakizaki rats to the same extent as sildenafil. Furthermore, the effects of LISWT were potentiated with sildenafil. Nevertheless, this was not mediated by a mechanism dependent on nitric oxide and cyclic guanosine monophosphate and the investigators encouraged further investigation of the mechanism of action of these devices.The first observation studies in patients who responded poorly to PDE5i therapy reported on the efficacy and safety of LISWT devices, especially in patients with ED of vascular origin and in those with a poor response to PDE5i treatment.

            Eighty percent of patients (40 of 50) completed the treatment and 12-month follow-up. Ten patients with similar demographic characteristics were excluded from the study because of loss to the first follow-up.Median age was 64.8 years and duration of ED was 70.5 months.The positive response rate was 60% of available subjects at the end of the study and 48% of the intent-to-treat population.Sixty percent of patients (24 of 40) showed improvement in efficacy parameters in all four assessments (IIEF-EF, SEP2, SEP3, and EHS) and responded positively to the GAQ. These changes were significant from the first follow-up (3 months after treatment).By the third month after treatment, 91.7% of responders to LISWT (22 of 24) maintained efficacy parameters up to the last follow-up visit 12 months after treatment.But a new study shows efficacy decrease after 24 months .