Effect of collagenase Clostridium histolyticum on penile vascular and morphological parameters in patients with Peyronie’s disease

Background To examine the changes in penile vascular parameters after the administration of collagenase Clostridium histolyticum (CCH) in patients with Peyronie's disease (PD). Methods We retrospectively reviewed the records for all patients treated with CCH for PD between 04/2014 and 05/2017 who underwent penile duplex Doppler ultrasound (PDDU) after pharmacologically induced erection both before and after four cycles of CCH treatment. The primary outcomes measured were changes in peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) after CCH treatment. Paired t-tests, chi-squared tests, and correlation coefficients were performed between functional and vascular parameters before and after four rounds of CCH to determine statistical significance (P<0.05). Results A total of 51 patients were included in the study. After four cycles of CCH therapy, there was no statistically significant change in PSV, EDV, RI, or International Index of Erectile Function score when compared to baseline. Similarly, there was no correlation between vascular parameters and change in curvature. There was a statistically significant change in penile curvature (60˚±16.9˚ to 40.8˚±14.9˚, P<0.001) and erect penile circumference (11.6±1.0 to 11.9±1.0 cm, P<0.05) after treatment. Conclusions In spite of a significant change in penile curvature, this change did not correlate with changing penile vascular or morphological parameters. Overall, CCH therapy seems to have a negligible impact on penile vasculature, furthering evidence of its favorable safety profile.