Low-Intensity Extracorporeal Shock Wave Therapy in Vasculogenic ED Refractory to PDE5 Inhibitors: A Prospective Study with 12- and 18-Month Outcomes

Li-ESWT pushed IIEF-EF from 11 to 21 at 12 months in 188 PDE5-refractory men — but scores slipped to 18 by 18 months

Journal: Archivio Italiano di Urologia e Andrologia | Published: 2026-03-02 | Type: Prospective Observational Study | PMID: 41778997 Authors: Saitta G, Di Paola G, Di Salvatore S, Calabrese B, Ceresoli AS, Mantovani F, Meazza AL, Seveso M (Istituto Clinico Città Studi and IRCCS Humanitas Research Hospital, Milan) Funding/COI: Not listed for either

Summary

Six weekly sessions of low-intensity extracorporeal shock wave therapy produced meaningful IIEF-EF gains in 188 men whose vasculogenic ED didn't respond to PDE5 inhibitors, with 65% still showing benefit at 12 months. The gains erode: by 18 months only 54% maintained improvement and the mean IIEF-EF score dropped from 21 back toward 18. Without a control group, this study cannot separate treatment effect from placebo, regression to the mean, or the natural fluctuation of ED severity.

Claims

• Mean IIEF-EF improved from 11.0 (baseline) to 21.0 at 12 months and 18.0 at 18 months
• 71% of patients showed improvement on the Erection Hardness Score (EHS ≥3) at 12 months
• 65% met the responder threshold (≥3-point IIEF-EF gain or EHS ≥3) at 12 months; 54% at 18 months
• Younger age (<45), shorter ED duration (<12 months), and moderate baseline severity predicted better response (p<0.05)
• No adverse events reported across the full cohort

Study Quality

This is a prospective observational study with a reasonable sample (n=188) and an 18-month follow-up horizon that exceeds most Li-ESWT literature. Outcome measures — IIEF-EF and EHS — are validated and the responder threshold (≥3 IIEF-EF points) aligns with established minimal clinically important difference criteria. Those are genuine strengths.

The fatal methodological gap is the absence of a control arm. Li-ESWT trials are particularly vulnerable to placebo response: men seeking treatment for ED, receiving regular clinical attention, and anticipating benefit routinely show IIEF improvements without any active intervention. A 10-point IIEF-EF jump (11→21) is large enough to be clinically meaningful if real — and large enough to be almost entirely placebo if not. The study design cannot distinguish between them. The cohort is also skewed old (mean age 66.6, mean ED duration 24 months), limiting generalizability to younger men despite the subgroup finding that younger patients do better.

Red Flags

• No control group — the study's primary limitation; stated by the authors themselves
• Funding source not disclosed; COI not disclosed — in a field with active device-industry investment, this is a notable omission
• Single-institution or dual-institution design with Italian patient selection; generalizability is unclear
• Efficacy decay from 12 to 18 months is not characterized beyond a percentage — no Kaplan-Meier or time-to-relapse analysis
• The subgroup finding that patients under 45 respond better is based on a small fraction of a 66.6-year-mean cohort — likely underpowered
• Protocol details (device model, energy flux density, pulse count) are not specified in the abstract — reproducibility is limited

Strengths

• Prospective design with pre-specified responder criteria
• 188 patients is larger than most Li-ESWT single-arm studies
• 18-month follow-up captures the durability question that 6- and 12-month studies leave open
• Identified clinically actionable predictors of response (age, ED duration, baseline severity)
• No adverse events across 188 patients adds to the safety signal for this modality

Verdict

This paper is useful for confirming what the broader Li-ESWT literature already suggests — the treatment moves IIEF scores, effects peak around 12 months, and they drift back. The 18-month data point is genuinely valuable and underreported in this space. But the missing control group means no one should read these effect sizes as causal estimates. The authors acknowledge this and call for larger controlled studies, which is the honest bottom line. File it as a moderately well-executed observational study that strengthens the case for a properly powered RCT, not one that settles the efficacy question.