presented at the annual meeting of the American Urological Association.
In a single-blind prospective study that evaluated low-intensity shock-wave therapy, researchers randomly assigned 36 men with ED to receive mechanical therapy (n = 22) or sham treatment (n = 14) on their flaccid penises.
The patients in arm 1 of the study received three treatments of 5,000 shocks (4 Hz, 0.12 mJ/mm2) with the UroGold 1000 device (SoftWave) at weeks 0, 3, and 6. Those in arm 2 received a regimen of 5,000 shocks at week 0 and 3,000 at weeks 2 and 3, which was repeated 3 weeks later. Patients who completed sham treatment were unblinded and crossed over to the opposite arm for active treatment.
At weeks 20 and 32, the researchers assessed changes in gray-scale ultrasound erectile tissue homogeneity of the corpora cavernosa using visual grading scores as well as changes in color Duplex Doppler ultrasound assessments of artery blood flow parameters between baseline and follow-up.
Better blood flow – But is that enough?
After shock-wave therapy, more men experienced either improvements in or no worsening of blood flow parameters relative to baseline than after sham treatment. The decrease in end-diastolic volume was statistically significant for men in the active treatment arm 2 at week 32 (P = .003), according to the researchers.
The number of men whose visual grading scores for ultrasound gray-scale images improved in the proximal region was consistently higher with active treatment than with placebo (arm 1: 88.9% vs. 11.1%; arm 2: 40% vs. 20%), with statistical significance in arm 1 at weeks 20 (P = .005) and 32 (P = .001). Patients who received sham treatment and who subsequently received active shock-wave therapy also had improved scores on gray-scale ultrasound (arm 1: 33.3% vs. 11.1%; arm 2: 40% vs. 20%).
Scores on the International Index of Erectile Function (IIEF) were nominally higher for men in active treatment whose visual grading scores had improved compared with those who did not show improvement.
The most common adverse event was transient discomfort after the shock-wave treatment, according to the researchers.
The study provides “a glimpse into the concept” that the mechanotransduction from a shock wave results in biochemical changes, including “activation of stem cells within the corpus cavernosum,” said Irwin Goldstein, MD, director of San Diego Sexual Medicine and clinical professor of surgery at the University of California, San Diego, who led the trial. “If I can activate stem cells,” he added, “theoretically, I can improve the health of tissue.”
Dr. Goldstein noted that the study is the first to use before-and-after objective gray-scale ultrasound imaging along with color Doppler ultrasound. “We could see gray scale changes and peak systolic velocity changes even with a small group,” he said.
Dr. Goldstein added that the trial is the first in which zero energy was used in the sham phase instead of less energy than active treatment. With the sham treatment, there was no benefit on the gray scale, which he said is “very important.”
He said his team is in the process of submitting a proposal for a larger prospective trial to confirm the findings.
Although the results are promising, the study did not evaluate what matters most to men, said Louis Kuritzky, MD, a family medicine physician and assistant professor emeritus at HCA UCF Family Medicine Residency, in Gainesville, Fla.
“Men don’t care what the flow velocity is – they care [whether] they get an erection sufficient for penetration and completion of intercourse. That trial did not look at those endpoints. It looked at surrogates. Those are encouraging, but that’s not what I think a clinician would base their decision upon about whether or not a patient should possibly participate in shock therapy.”