Various studies using animal models of CN neuroparaxia and clinical trials have demonstrated somewhat beneficial effect of PDE-5 inhibitors on smooth muscle cells of the corpus cavernosum. PDE-5 inhibitors including sildenafil have demonstrated the effectiveness in the management of postprostatectomy ED. In the animal experiments, PDE-5 inhibitors lowered the severity of the fibrosis in the corpus cavernosum of rats with CN cutting. In the clinical trials, on-demand dosing or routine dosing of PDE-5 inhibitors improved the potency rates in men received NSRP, and improvements of the potency rate did not appear to be statistically different among two dosing regimens.
But, there are few studies on the potency rate according to the start time of the administration of PDE-5 inhibitors (eg. early vs. delayed post-operative dosing). At present, it is not conclusive that whether nerve-sparing RALP provides more higher potency rate than conventional surgery in men with prostate cancers. But, with more precise dissection of CN, the robotic surgery appears to have more chances to maintain the potency in men received RP.
