Short summary

This randomised, single-blinded, placebo-controlled trial investigates if early low intensity shock wave therapy can help men undergoing radical prostatectomy maintain their erectile function.

Rationale

A large percentage of radically prostatectomised men experience erectile dysfunction after their surgery (1). For many years, erectile dysfunction was an inevitable consequence of having the prostate removed as the nerve bundles that facilitate erections are in close proximity to the prostate and were thus removed along with the prostate. In recent years, nerve-sparing surgical techniques have been developed, effectively reducing the risk of erectile dysfunction postoperatively. However, a sizable number of men develop erectile dysfunction despite nerve-sparing surgery thus indicating that preserving the nerves alone is not sufficient (2, 3). 

Neurapraxia of the cavernous nerves is not uncommon and is responsible for the temporary loss of erectile function that occurs for almost all patients after radical prostatectomy. This is not to be confused with the long-term erectile dysfunction, that this trial seeks to prevent. The neurapraxia, albeit temporary, reduces the blood flow to the cavernous bodies which is usually mediated by erections resulting in poor oxygenation of the cavernous bodies. Oxygen being as important as it is for the production of NO, poor oxygenation can severely affect the erectile function. 

With reduced blood flow and reduced oxygenation of the cavernous bodies as a plausible component in the complex basis for erectile dysfunction following radical prostatectomy, low intensity shock wave therapy (LI-SWT) is an option for improving the blood flow to the cavernous bodies. In animal studies with diabetic rats, LI-SWT has been proven capable of inducing neoangiogenesis and support the healing of wounds through stimulating the expression of endotelial nitrogenoxid syntase (eNOS) and vascular endothelial growth factor (VEGF)(4). Additionally LI-SWT has been used on rat models with diabetes mellitus associated erectile dysfunction and was found to significantly improve the erectile function albeit not capable of fully restoring it(5).

In human trials, LI-SWT was found to be effective in improving the erectile function of men with erectile dysfunction(6, 7). Moreover it's a safe treatment with no discomfort to the patients and it is easy to apply. 

This trial differentiates itself from previously conducted trials on humans is in the early initiation of the treatment and its preventative intent. Where other trials have specifically treated erectile dysfunction, this trial treats patients three weeks after their radical prostatectomy and all patients included in the trial have no erectile dysfunction or urinary incontinence.

1. Tal R, Alphs HH, Krebs P, Nelson CJ, Mulhall JP. Erectile function recovery rate after radical prostatectomy: a meta-analysis. J Sex Med. 2009;6(9):2538-46.

2. Catalona WJ, Dresner SM. Nerve-sparing radical prostatectomy: extraprostatic tumor extension and preservation of erectile function. J Urol. 1985;134(6):1149-51.

3. Catalona WJ, Basler JW. Return of erections and urinary continence following nerve sparing radical retropubic prostatectomy. J Urol. 1993;150(3):905-7.

4. Kuo YR, Wang CT, Wang FS, Chiang YC, Wang CJ. Extracorporeal shock-wave therapy enhanced wound healing via increasing topical blood perfusion and tissue regeneration in a rat model of STZ-induced diabetes. Wound Repair Regen. 2009;17(4):522-30.

5. Qiu X, Lin G, Xin Z, Ferretti L, Zhang H, Lue TF, et al. Effects of low-energy shockwave therapy on the erectile function and tissue of a diabetic rat model. J Sex Med. 2013;10(3):738-46.

6. Olsen AB, Persiani M, Boie S, Hanna M, Lund L. Can low-intensity extracorporeal shockwave therapy improve erectile dysfunction? A prospective, randomized, double-blind, placebo-controlled study. Scand J Urol. 2015;49(4):329-33.

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.

Description of the cohort

Inclusion criteria:

Men up to 80 years old set for either nerve sparing or non-nerve sparing radical prostatectomy.

In a relationship for more than three months.

Sexually active.

No urinary incontinence or erectile dysfunction.

Can give informed consent.

Data and biological material

The erectile function will be assessed using questionnaires and objective measurements of nocturnal erections.

Collaborating researchers and departments

Department of Urology, Odense University Hospital

• Ali Moumneh, BSc.med

• Sune Møller Skov-Jeppesen, MD, Ph.D-student

• Grzegorz Fojecki, MD, Ph.D.

• Professor of Urology and Head of Research, Lars Lund, DMSc

OPEN Patient data Explorative Network, Odense University Hospital, University of Southern Denmark