Low-intensity extracorporeal shockwave therapy for erectile dysfunction: an overview of systematic reviews

Background: Low-intensity extracorporeal shockwave therapy (LI-ESWT) may be a successful complementary treatment approach for erectile dysfunction (ED). In this study, we aimed to review and summarize the research evidence from systematic reviews (SRs)/meta-analyses (MAs) regarding the clinical effectiveness of LI-ESWT for ED. Methods: Studies on LI-ESWT for ED were searched using eight electronic databases from establishment of each database to 31 June 2021 with the language restrictions of Chinese and English. All articles were screened, and qualifying data were recorded based on the inclusion criteria. Methods including: the Assessing the Methodological Quality of Systematic Reviews 2 (AMSTAR-2); the Risk of Bias in Systematic Reviews (ROBIS); the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA); and Grading of Recommendations, Assessment Development, and the Evaluation (GRADE) were used by two independent raters to assess methodological quality, risk of bias, reporting quality, and SR evidence of quality, respectively. Results: Eight SRs/MAs met all inclusion criteria. Seven reviews were rated as critically low on overall confidence and one review was low on confidence based on the AMSTAR-2 appraisal tool. While most PRISMA criteria were met, the major reporting flaws were in relation the financial statements not being included, along with no protocol registrations. Three SRs/MAs were classed as low risk regarding bias as measured by the ROBIS tool. Based on the GRADE method, only one SRs/MAs of high-quality evidence and seven SRs/MAs of moderate-quality evidence were found. The present research results supported LI-ESWT as a complementary therapy for ED patients, but the evidence should be considered carefully due to the methodological flaws identified. Discussion: Our results showed that LI-ESWT as an adjunctive therapy has benefits for ED patients. There were no obvious side effects, and the number of shockwave treatments and energy flux density (EFD) would affect the IIEF-EF, EHS and PSV scores. However, due to the limited sample size and the quality of reporting evidence, our conclusions may not be fully representative.