Low-intensity Shock Wave Therapy for the Treatment of Vasculogenic Erectile Dysfunction

A Narrative Review of Technical Considerations and Treatment Outcomes

Pedro Simoes de Oliveira; Matthew J. Ziegelmann

Disclosures

Transl Androl Urol. 2021;10(6):2617-2628. 

In This Article

Abstract and Introduction

Abstract

Erectile dysfunction (ED) impacts a significant portion of the aging male population. Standard treatments such as oral medications, intracavernosal injections, intraurethral suppositories, vacuum erection aids, and penile prosthesis placement have stood the test of time. Recently, there has been a growing interest in the concept of regenerative medicine with the goal of restoring or renewing functional tissue. Low intensity shock wave therapy (LiSWT) is one example of a regenerative therapy. A strong body of basic science data suggests that shockwaves, when applied to local tissue, will encourage blood vessel and nerve regeneration. Clinical evidence supports the use of LiSWT to treat conditions ranging from ischemic heart disease, musculoskeletal injuries, and even chronic non-healing wounds. LiSWT is also being used to treat male sexual dysfunction conditions such as Peyronie's Disease and ED. The first studied application of LiSWT for ED was published in 2010. Since then multiple randomized, sham-controlled trials have sought to evaluate outcomes for this novel therapy in men with vasculogenic ED. Additionally, several meta-analyses are available with pooled data suggesting that LiSWT results in a significantly greater improvement in erectile function relative to sham-control. Despite these promising findings, the current body of literature is marred by significant heterogeneity relating to treatment protocols, patient populations, and follow-up duration. Further work is necessary to determine optimal device technologies, patient characteristics, and treatment duration prior to considering LiSWT as standard of care for men with ED.

Introduction

Erectile dysfunction (ED) refers to the inability to achieve and/or sustain an erection satisfactory for sexual intercourse. An estimated 30–50% of men between the ages of 40–70 years of age suffer from moderate or severe ED based on data from the United States and Europe.[1,2] Treatment begins with lifestyle modification followed by medical therapy with phosphodiesterase-5 inhibitors (PDE5i). In medication refractory patients, or in those with intolerable side effects, published guidelines encourage clinicians to discuss established treatment such as vacuum erection devices, self-administered intracavernosal injection of erectogenic agents, intraurethral suppositories, and penile prosthesis placement.[3]

Over the past several years, there has been considerable interest in the concept of "regenerative" therapies for ED treatment. This is logical, as ED results in anatomic and functional changes to the erectile tissue characterized by progressive cavernosal fibrosis.[4] Regenerative treatments include injections of stem cells, platelet rich plasma, and low-intensity shockwave therapy (LiSWT). There is amassing animal data suggesting that these approaches may result in angiogenesis and neurogenesis, thereby "restoring" dysfunctional erectile tissue.[5] To date there is limited human data to support regenerative therapies as a reliable treatment for ED. Also, the patient characteristics associated with treatment success are unclear. This has not stopped a barrage of clinics throughout the world from offering regenerative therapies for ED, sometimes with unsubstantiated claims of benefit, aggressive marketing campaigns, and exorbitant out of pocket fees.[6]

Shock wave therapy (SWT) has been widely used for many years to treat many conditions. It was first described 40 years ago for the treatment of renal stones[7] and later for bone non-unions,[8] chronic wounds,[9] ischemic heart disease[10] and more recently for sexual dysfunction including Peyronie's Disease and erectile dysfunction (ED).[11,12] High-energy SWT (10–20 kV) is used to fragmentize urinary tract stones whereas SWT using lower energy settings (<0.2 mJ/mm2) has been proposed to treat other conditions based on animal model data showing potential regenerative properties through angiogenesis and neurogenesis.[7,8]

Due to the minimally-invasive nature of this approach, SWT is an attractive treatment modality for many patients and clinicians. Of the ED regenerative therapies, LiSWT has the largest body of literature, including several randomized-controlled trials and meta-analyses.[9] The results are somewhat varied, and there inherent challenges in deciphering treatment outcomes due to variations in treatment protocols (energy settings, number of shocks delivered, duration of therapy, etc.) and patient populations. Also, not all shockwave technologies are created equal and many of the devices used in commonplace are unlikely to exert any effect on erectile tissue.[10] Given the controversy and lack of clarity surrounding LiSWT, as well as the increasing number of clinicians who are offering LiSWT within and outside various research protocols, herein we sought to provide a comprehensive review of LiSWT for the treatment of vasculogenic ED with emphasis on mechanism of action, device technology, published data, and future considerations.[11] We present the following article in accordance with the Narrative Review Checklist (available at http://dx.doi.org/10.21037/tau-20-1286).

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