Low-intensity shockwave therapy for erectile dysfunction.

Abstract

Rationale: Low-intensity shockwave therapy (LiSWT) is a new way of treating erectile dysfunction using sound waves to help improve blood flow to the penis. No existing systematic reviews comparing LiSWT to placebo or other therapies for treating erectile dysfunction have used rigorous Cochrane methodology. Many existing studies appear to be of poor methodological quality, and several trials are ongoing, reflecting an evolving evidence base. Therefore, it is unclear whether LiSWT truly helps men who have erectile dysfunction. Furthermore, there is very limited focus on patient-important outcomes in the existing systematic reviews. In this comprehensive Cochrane review, we compared LiSWT to sham therapy to evaluate its efficacy and safety.

Objectives: To evaluate the benefits and harms of low-intensity shockwave therapy for erectile dysfunction in men compared to sham treatment.

Search methods: We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, Scopus, and two trial registries up to 7 July 2024. We applied no restrictions on publication status or language.

Eligibility criteria: We included randomized controlled trials (RCTs) that compared LiSWT to either sham or no treatment. We excluded trials involving people with prior kidney transplants or who had surgical procedures to remove the prostate gland (i.e. radical prostatectomy).

Outcomes: Critical outcomes were erectile function, discontinuation from treatment, and treatment-related adverse events; important outcomes were patient/partner satisfaction, penile rigidity, and quality of sexual life. We assessed all outcomes in the short term (≤ 3 months) and long term (> 3 months).

Risk of bias: We assessed the risk of bias using Cochrane's risk of bias assessment tool (RoB1).

Synthesis methods: We performed statistical analyses following Cochrane Handbook of Systematic Reviews of Interventions guidance. We synthesized results for each outcome using meta-analysis using a random-effects model. We used GRADE to assess the certainty of evidence.

Included studies: We focused on RCTs that applied LiSWT treatment utilizing electrohydraulic, electromagnetic, or piezoelectric energy. We included 21 RCTs, including 1357 randomized participants (men aged 39 to 65 years old with erectile dysfunction between 3 and 68 months); 16 were published in full text, and the rest as abstract proceedings. The baseline International Index of Erectile Function-Erectile Function domain (IIEF-EF) scores of participants in these studies ranged from seven to 20. Based on this scale, most men had mild-to-moderate (12 to 16) and mild (17 to 21) erectile dysfunction.

Synthesis of results: We included 21 RCTs that randomized 1357 participants. The certainty of the evidence for reported outcomes was low, mostly due to inconsistency, imprecision, and study limitations. Erectile function Based on the IIEF-EF scale (6 to 30; higher score indicates higher erectile function; minimal clinically important difference (MCID): 4 point change), LiSWT, compared to sham treatment, may have a small effect on erectile function in the short term (mean difference (MD) 3.89 points higher, 95% confidence interval (CI) 2.89 higher to 4.89 higher; I² = 62%; 15 studies, 937 participants; low-certainty evidence). However, based on the selected MCID, this small effect may not be clinically important. In the long term, it may improve erectile function (MD 5.25 points higher, 95% CI 2.47 higher to 8.04 higher; I² = 87%; 5 studies, 276 participants; low-certainty evidence). Discontinuation from treatment LiSWT, compared to sham treatment, may have little to no effect on discontinuation from treatment in the short term (RR 0.77, 95% CI 0.47 to 1.27 higher; I² = 0%; 17 studies, 1132 participants; low-certainty evidence). This corresponds to 15 fewer (34 fewer to 17 more) discontinuations from treatment with the use of LiSWT per 1000 patients. There were no studies with an active treatment period longer than three months; therefore, we found no eligible data on this outcome in the long term. Treatment-related adverse events LiSWT, compared to sham treatment, may have little to no effect on treatment-related adverse events in the short term (risk difference (RD) 0.00, 95% CI -0.01 to 0.02; I² = 0%; 20 studies, 1400 participants; low-certainty evidence). Long term, it may also have little to no effect on treatment-related adverse events (RD 0.00, 95% CI -0.02 to 0.02; I² = 0%; 6 studies, 411 participants; low-certainty evidence). Patient/partner satisfaction We found no evidence on patient or partner satisfaction in either the short or long term. Penile rigidity Based on the Erectile Hardness Scale (EHS) (1 to 4; higher score indicates higher penile rigidity; MCID: 1 point change), LiSWT compared to sham treatment may improve penile rigidity in the short term (MD 1.06 points higher, 95% CI 0.83 higher to 1.28 higher; I² = 53%; 4 studies, 252 participants; low-certainty evidence). In the long term, it may have a small improving effect on penile rigidity (MD 0.91 points higher, 95% CI 0.36 higher to 1.46 higher; I² = 89%; 3 studies, 169 participants; low-certainty evidence). However, based on the selected MCID, this small effect may not be clinically important. Sexual quality of life We found no evidence on sexual quality of life in either the short or long term.

Authors' conclusions: LiSWT may have a small effect on erectile function in the short term, although it may not be perceived to be clinically important by men with erectile dysfunction. It may improve erectile function in the long term. There may be little to no difference in treatment discontinuations in the short term. Since all eligible trials applied a treatment duration of three months or less, we found no data to compare treatment discontinuations in the long term. LiSWT may have little to no effect on treatment-related adverse events in the short or long term, and may improve penile rigidity in the short term. In the long term, LiSWT may have a small improving effect on penile rigidity that may not be clinically important. We found no evidence on patient/partner satisfaction or sexual quality of life, either short or long term. The certainty of evidence was low for all outcomes due to shortcomings in the methodology of the included studies. Several studies were industry-funded, mainly by device makers.

Funding: This Cochrane review had no dedicated funding.

Registration: Protocol (2023): doi.org/10.1002/14651858.CD013166.pub2.