Low-Intensity Extracorporeal Shock Wave Therapy for ED

Low-intensity extracorporeal shock wave therapy (Li-ESWT) is used in urology primarily to treat erectile dysfunction (ED), fibrotic disease of the tunica albuginea (Peyronie’s disease), chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), and bladder dysfunction. Li-ESWT has also been widely applied in other medical fields to treat musculoskeletal, cardiovascular, and neurological disorders, as well as impaired wound healing.

What Are Shock Waves?

A shock wave is an acoustic wave that carries energy. It travels rapidly through a specialized coupling medium and concentrates its energy on a tissue or target at a predetermined depth, producing a therapeutic effect. Shock waves deliver energy in two main ways. First, a large positive-pressure wave forms over a very short period and directly strikes the tissue or target, producing fragmentation and disintegration. In urology, this principle is used in high-energy extracorporeal shock wave lithotripsy to treat kidney or ureteral stones. Second, the smaller tensile wave that follows creates microscopic bubbles within the tissue (cavitation). When these bubbles collapse, they release pressure and energy that stimulate soft-tissue repair and regeneration. This is the principal therapeutic mechanism of Li-ESWT.

Biological Effects of Li-ESWT

When Li-ESWT reaches the target tissue, it subjects cells to mechanical stress. Stimulation of cellular mechanoreceptors initiates a cascade of biological responses, including the release of regeneration-related molecules such as growth factors and the regulation of signaling molecules such as chemokines and cytokines. These responses activate mesenchymal stem cells, promote cell proliferation and migration, reduce inflammation, and support tissue remodeling and regeneration. Li-ESWT also induces the release of vascular endothelial growth factor (VEGF), thereby promoting angiogenesis and neovascularization. The resulting improvement in tissue perfusion increases oxygen and nutrient delivery. In addition, Li-ESWT may facilitate nerve repair and restore normal endothelial signaling (Figure 1).

Mechanisms of Action in Erectile Dysfunction

Li-ESWT is a noninvasive treatment for erectile dysfunction. Through multiple mechanisms, it stimulates cellular regeneration within the corpora cavernosa, supports tissue renewal and repair, and improves cavernosal structure and function. It also promotes neovascularization within the corpora cavernosa, increases penile blood flow, improves penile circulation, and facilitates cavernosal engorgement and erection (Table 1).

Mechanism	Biological Effect	Clinical Benefit
Mechanical Stress and Microtrauma	Shock waves induce controlled microtrauma, initiating repair responses in the corpora cavernosa and surrounding blood vessels.	Initiates tissue repair and promotes the release of growth factors.
Angiogenesis	Upregulates VEGF (vascular endothelial growth factor), eNOS (endothelial nitric oxide synthase), and bFGF (basic fibroblast growth factor), promoting the formation of new blood vessels.	Increases penile blood flow and improves erectile function.
Neovascularization and Improved Endothelial Function	Increases nitric oxide (NO) release and promotes arterial vasodilation.	Improves vascular function and helps maintain erectile rigidity.
Stem Cell Activation and Tissue Regeneration	Stimulates mesenchymal stem cells and the release of cytokines and growth factors, promoting regeneration of smooth muscle cells in the corpora cavernosa.	Improves the structure and function of cavernosal tissue.
Nerve Regeneration	Increases the expression of neurotrophic factors, such as nerve growth factor (NGF), and supports nerve repair.	May be particularly beneficial for neurogenic ED following prostate surgery or associated with diabetes.

Treatment Procedure

During Li-ESWT for erectile dysfunction, the applicator is placed against multiple treatment sites along the penis and perineum. Approximately 3,000 shock wave pulses are delivered during each session (Figure 2). A session takes about 20 minutes and does not require anesthesia. A complete course generally consists of 6 to 12 sessions administered over approximately 6 weeks; this schedule tends to produce the best results. Discomfort and adverse effects are uncommon. If mild stinging or tingling occurs, the energy level and pulse frequency can be adjusted.

Contraindications to Li-ESWT

•  Penile cancer or another malignancy within the treatment area.
•  Presence of a penile prosthesis.
•  A bleeding disorder, such as hemophilia, or ongoing anticoagulant therapy, unless the patient is closely monitored.
•  An active infection or open wound involving the genital or perineal region.
•  Severe cardiovascular disease, including unstable angina, myocardial infarction within the previous 6 months, or a severe arrhythmia.
•  Erectile dysfunction caused by a severe neurological disorder, if clinical assessment indicates that shock wave therapy is unsuitable.
•  Severe Peyronie’s disease with extensive calcification.

Treatment Outcomes and Patient Satisfaction

• Improved erectile function: Erectile function and treatment response are commonly assessed using the International Index of Erectile Function (IIEF) questionnaire. Multiple studies have shown that Li-ESWT can significantly improve IIEF scores, particularly in patients with vasculogenic ED. Its effects appear more limited in neurogenic or psychogenic ED.
• Improved sexual satisfaction: Patients have reported greater satisfaction with sexual activity after Li-ESWT and an improved ability to engage in satisfactory intercourse.
• Durability: Some studies suggest that the benefits of Li-ESWT may persist for 6 to 12 months or longer. One study reported a 50% success rate 2 years after treatment.
• Favorable safety profile: Most studies have not reported serious adverse events, indicating that the treatment is generally well tolerated.
• Combination therapy: Improvement may be greater when Li-ESWT is administered together with a phosphodiesterase type 5 (PDE5) inhibitor, such as tadalafil (Cialis).
• Greater benefit in mild-to-moderate vasculogenic ED: Patients with mild ED have shown significant improvement in erectile-function scores. In some studies, the improvement in patients with moderate or severe ED did not reach statistical significance; however, outcomes in moderate ED were still better than those in severe ED.

Conclusion

Taken together, basic and clinical studies suggest that Li-ESWT has favorable efficacy and safety in the treatment of erectile dysfunction and may help improve and maintain quality of life. It is particularly suitable for patients with vasculogenic ED, with better outcomes generally observed in mild-to-moderate disease. The European Association of Urology also includes Li-ESWT among the first-line treatment options for erectile dysfunction. However, its effects appear more limited in neurogenic or psychogenic ED, and further research is needed. Patients should therefore undergo a thorough evaluation and diagnosis by a urologist before treatment to determine whether Li-ESWT is appropriate.

References

1. Fode M, Hatzichristodoulou G, Serefoglu EC, et al. Low-intensity shockwave therapy for erectile dysfunction: is the evidence strong enough? Nat Rev Urol. 2017;14(10):593–606.
2. Lu Z, Lin G, Reed-Maldonado A, et al. Low-intensity extracorporeal shock wave treatment improves erectile function: a systematic review and meta-analysis. Eur Urol. 2017;71(2):223–33.
3. Rizk PJ, Krieger JR, Kohn TP, et al. Low-intensity shockwave therapy for erectile dysfunction. Sex Med Rev. 2018;6(4):624–30.
4. Sokolakis I, Dimitriadis F, Teo P, et al. The basic science behind low-intensity extracorporeal shockwave therapy for erectile dysfunction: a systematic scoping review of pre-clinical studies. J Sex Med. 2019;16(2):168–94.
5. Lu Z, Lin G, Reed-Maldonado A, Wang C, Lee YC, Lue TF. Low-intensity extracorporeal shock wave treatment improves erectile function: a systematic review and meta-analysis. Eur Urol. 2017;71(2):223–33.
6. Clavijo RI, Kohn TP, Kohn JR, Ramasamy R. Effects of low-intensity extracorporeal shockwave therapy on erectile dysfunction: a systematic review and meta-analysis. J Sex Med. 2017;14(1):27–35.
7. Man L, Li G. Low-intensity extracorporeal shock wave therapy for erectile dysfunction: a systematic review and meta-analysis. Urology. 2018;119:97–103.
8. Dong L, Chang D, Zhang X, Li J, Yang F. Effect of low-intensity extracorporeal shock wave therapy on patients with erectile dysfunction: a systematic review and meta-analysis. Am J Mens Health. 2019;13(6):1–11.
9. Yao F, Li S, Lin H, Chen L, Yang D. Efficacy of low-intensity extracorporeal shock wave therapy for erectile dysfunction: a systematic review and meta-analysis of randomized controlled trials. Am J Mens Health. 2022;16(2):1–13.
10. Wei X, Li Y, Zhao Y, Wu T, Huang Y. Network meta-analysis of low-intensity shock wave therapy parameters for vasculogenic erectile dysfunction. Front Pharmacol. 2024;15:1208699.