Low-Intensity Extracorporeal Shockwave Therapy (LIESWT)
The proposed mechanisms of action of low-intensity extracorporeal shock wave therapy (LIESWT) to promote neovascularization are thought to be related to the release of various angiogenic growth factors and activation tissue repair functions such as enhanced macrophage activity, alterations in cellular apoptosis, greater synthesis of cellular proteins and activation as well as enhanced recruitment and subsequent differentiation of stem/progenitor cells [42,43]. There is strong emerging literature to support the use of LIESWT, especially in vasculogenic ED, with many clinical studies reporting encouraging results in the use of LIESWT with improved erectile function, a good safety record and short-term durability [44,45]. The therapeutic efficacy of LIESWT in erectile function recovery appeared to last at least three months during the duration of study and patients with mild/moderate ED reported higher therapeutic efficacy than patients with more severe ED or those with multiple medical comorbidities.
While current clinical studies show that the stimulation effects and therapeutic mechanisms among LIESWT machines are similar, regardless of the physical differences and the treatment template, it remains unknown if one machine is superior to another . Furthermore, there is a need to define the optimal LIESWT treatment protocol including the ideal treatment template, the modality of shock wave energy, the emission frequency and the total energy delivery. More stringent randomized controlled trials with longer-term follow-ups are warranted before LIESWT technology is accepted as the standard of care in ED.
Shockwave treatment of erectile dysfunction
The current nonsurgical treatment modalities in the management of erectile dysfunction (ED) mainly consist of oral phosphodiesterase type 5 inhibitors (PDE5is) and/or intracavernosal injections of vasodilating agents. These treatments are very effective and are reasonably safe with rare unwanted or adverse effects. However, they all share the same major drawback: they do not alter the underlying pathophysiology of the erectile mechanism. These treatments are usually taken on demand, prior to the sexual act, and their effect is essentially time limited. Although daily administration of a PDE5i instead of on-demand treatment does address some of these problems, it still does not modify the pathophysiology of the erectile process. Moreover, the evidence that its effect on the erectile tissue is long-lasting is very limited. Presently, only a small number of men with ED can be offered treatment that would restore their spontaneous erectile function. This group includes those who would benefit from various lifestyle or drug regimen modifications, those who can be treated for relevant endocrine disorders, or those with vasculogenic ED who would benefit from microvascular surgery. Most patients with ED rely on their treatment in order to maintain their sexual function; providing a treatment for men with ED that is rehabilitative or even curative and enables them to regain spontaneous sexual activity with normal intimacy and without adverse effects is an unmet medical goal. Recently, data from several studies have accumulated that this goal could probably be met by low-intensity extracorporeal shockwave therapy (LI-ESWT) of the corpora cavernosa. This review intends to summarize the scientific background underlying the effect of this energy as well as recent clinical evidence of its effect in patients with vasculogenic ED.
Clinical trial update on shockwave therapy and future of erectile function restoration
Our interim analysis of a phase II clinical trial on low-intensity extracorporeal shockwave therapy (Li-ESWT) for men with erectile dysfunction (ED) has demonstrated it is safe with no reported adverse outcomes. Interim analysis has demonstrated Sexual Encounter Profile 3 (ability to maintain erection till completion) was achieved in 60% of men prior to Li-ESWT, which increased to 90% after treatment. Nevertheless, limitations of our clinical trial include the lack of a sham arm and our inability to exclude men with psychogenic ED. We have begun recruitment of our phase III clinical trial that will allow assessment of treatment efficacy against a sham control arm. There exists substantial interest in the use of restorative therapies (i.e., Li-ESWT, stem cells, and platelet rich plasma) for men with ED with the potential to combine therapies to potentially lead to an augmented response.
Clinical studies on low intensity extracorporeal shockwave therapy for erectile dysfunction: a systematic review and meta-analysis of randomised controlled trials
In a recent meta-analysis of 10 randomized controlled trials involving a total of nearly 900 men with vasculogenic ED, researchers reported that, compared with sham treatment, LISWT resulted in significant improvements in measures of erectile function and penile blood flow.