Can low‑intensity extracorporeal shockwave therapy (Li‑ESWT) be used to treat mild‑to‑moderate vasculogenic erectile dysfunction in men who have not responded to phosphodiesterase‑5 inhibitors, and what is the recommended treatment protocol?

Low-Intensity Extracorporeal Shockwave Therapy (Li-ESWT) for Erectile Dysfunction

Li-ESWT may be used in men with mild vasculogenic erectile dysfunction, including those who have not responded to PDE5 inhibitors, though the evidence remains weak and no standardized treatment protocol exists. 1

Current Guideline Recommendations

The 2025 European Association of Urology (EAU) guidelines provide a weak recommendation for Li-ESWT use specifically in men with mild vasculogenic ED. 1 Importantly, the guidelines explicitly note that Li-ESWT has shown benefit in PDE5 inhibitor non-responders 1, making it a reasonable option for your specific clinical scenario.

Key Evidence Points

Efficacy Data:

• Pooled analyses of randomized controlled trials demonstrate a mean improvement in IIEF-EF scores of approximately 4 points 1
• Li-ESWT is described as "the only marketed treatment potentially offering a cure for ED" 1
• Effects diminish over time but remain detectable up to 5 years in some cases 1

For PDE5i Non-Responders Specifically:

• Studies show 60-67% of PDE5i non-responders can achieve erections hard enough for intercourse (EHS ≥3) when Li-ESWT is combined with continued PDE5i use 2, 3
• Success rates are higher in patients with less severe baseline ED (EHS 2: 78.9% vs EHS 1: 35.7%) 2

Critical Limitations

The major clinical challenge is the absence of a standardized treatment protocol. 1 This is explicitly acknowledged in the EAU guidelines and represents a significant barrier to widespread implementation. The evidence shows substantial protocol variations across studies, limiting the strength of recommendations. 1

Treatment Protocols Used in Research

While no consensus exists, research protocols typically include:

Common Parameters:

• Duration: 8-12 weekly sessions 4, 3, 5
• Shockwave number: 1,500-5,000 shocks per session 3, 6, 5
• Energy level: 0.09 mJ/mm² 3, 6
• Application sites: Penile shaft (both corpora cavernosa) and perineum (both crura) 3, 6

One representative protocol used 1,500 strokes distributed across 5 penile locations over 8 weekly sessions 5. Another used 3,000 shockwaves weekly for 12 weeks 2.

Patient Selection Criteria

Best Candidates:

• Mild-to-moderate vasculogenic ED (not severe ED) 4
• Baseline IIEF-5 scores suggesting moderate impairment 4, 5
• Peak systolic velocity <30 cm/s on penile Doppler (if available) 5

Poor Candidates:

• Diabetic patients show minimal benefit (only 6.7% improvement rate) 5
• Severe ED patients respond poorly 4, 6

Neutral Factors (do not affect outcomes):

• Smoking status 5
• Previous pelvic surgery 5
• Concurrent PDE5i use 5

Combination Therapy Approach

The evidence supports combining Li-ESWT with other treatments rather than using it alone. 1 Specifically:

• Li-ESWT + daily tadalafil shows enhanced results 1
• Li-ESWT + vacuum erection devices demonstrates benefit 1
• Patients should continue their regular PDE5i regimen during and after Li-ESWT 2, 3

This multimodal approach appears more effective than monotherapy, particularly in PDE5i non-responders.

Expected Outcomes and Timeline

Short-term (1-3 months):

• Mean IIEF-5 improvement from ~12 to ~16 points 7
• 51.8% of patients report satisfactory sexual intercourse at 6 months 4

Long-term (12-30 months):

• 76.3% of initial responders maintain improvement at 30 months 4
• Overall sustained success rate of 39.5% at 30 months without PDE5i use 4

Safety Profile

Li-ESWT demonstrates excellent safety with no noteworthy adverse events reported across multiple studies. 4, 3, 6 This makes it a low-risk option even when efficacy remains uncertain.

Clinical Decision Algorithm

For your patient (PDE5i non-responder with mild-to-moderate vasculogenic ED):

1. Confirm vasculogenic etiology and rule out severe ED
2. Verify proper PDE5i use (correct dosing, timing, sexual stimulation) before proceeding 1
3. Consider Li-ESWT if:
   • Patient has mild-to-moderate (not severe) ED
   • Patient is non-diabetic or has well-controlled diabetes
   • Patient desires potential disease-modifying treatment
4. Implement combination approach:
   • Continue PDE5i therapy during Li-ESWT
   • Consider daily tadalafil specifically
5. Set realistic expectations:
   • 60-67% response rate in PDE5i non-responders
   • Effects may diminish over time
   • Multiple sessions required (8-12 weeks minimum)

Important Caveats

The benefit "appears mild and may not be perceived as clinically significant by the patient." 1 This critical statement from the EAU guidelines must be communicated clearly during shared decision-making.

The 2018 AUA guidelines do not include Li-ESWT in their recommendations 8, reflecting the evolving and still-uncertain evidence base. The treatment remains in the "innovative modalities" category requiring further validation through large-scale, placebo-controlled studies. 1

Given the weak evidence, lack of standardized protocols, and modest clinical benefit, Li-ESWT should be positioned as an experimental adjunct to continued PDE5i therapy rather than a standalone solution for PDE5i non-responders. The strongest evidence supports its use in mild vasculogenic ED, with combination therapy offering the best chance of meaningful improvement. 1, 2