Is sildenafil failure in men after radical retropubic prostatectomy (RRP) due to arterial disease? Penile duplex Doppler findings in 174 men after RRP

Abstract

Sildenafil is frequently the first-line treatment for post-radical retropubic prostatectomy (RRP) erectile dysfunction (ED) with maximum treatment satisfaction rates of 43% -80%. The etiology of erectile dysfunction after RRP has been attributed to psychogenic, vascular, veno-occlusive or nerve injury causes. The purpose of this study was to gain insight into the penile duplex Doppler arterial parameters in men with ED after RRP who failed sildenafil. The purpose was to assess whether sildenafil failure after RRP is associated with underlying corporal arterial disease. A total of 174 consecutive men presenting with sildenafil refractory ED after nerve-sparing RRP underwent color duplex penile Doppler evaluation with vasoactive injection. Mean age was 59.6 y and mean time from surgery was 11.6 months. Some 81% (141=174) of the men had no preoperative ED (PED). Significant differences in penile duplex Doppler parameters for arterial disease were seen between men with and without PED. In men without PED, 19% (27=141) manifested arterial insufficiency. However, in men with PED, 50% (16=33) demonstrated arterial disease. Nerve sparing status did not affect the presence of arterial disease. Sildenafil refractory erectile dysfunction after RRP in men without PED is not predominantly associated with penile Doppler parameters consistent with arterial insufficiency.

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

“…Using a PSV < 30 cm/s and EDV ≤ 5 cm/s as the diagnostic criteria, our data also showed a low incidence of arterial insufficiency in both non-responders and responders (23.7% and 12.9%, respectively). This finding was comparable to the results of a previous study by McCullough et al [10]. In the aforementioned study, a low incidence of arterial insufficiency (19%) in sildenafil non-responders receiving nerve-sparing radical prostatectomy using a PSV < 25 cm/s as the diagnostic criteria was also noted.…”

Toward a new ‘EPOCH’: optimising treatment outcomes with phosphodiesterase type 5 inhibitors for erectile dysfunction

“…In another, smaller trial, treatment with a statin for up to 12 weeks significantly improved EF (increase in EF domain score = 7.8; p = 0.04), and the clinical benefits of statins on EF were observed as early as treatment week 6 (140). Nightly treatment with a PDE5 inhibitor has also been shown to be effective in enhancing EF in patients with arteriogenic ED (141); many patients with inadequate responses to PDE5 inhibitors after prostatectomy have arterial insufficiency (142,143). Certain studies have suggested that enhanced control of cardiovascular risk factors and/or statin treatment may increase the efficacy of PDE5 inhibitors (vs. placebo + PDE5 inhibitors) (144,145).…”

Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra®

“…5 Patients with a history of pelvic surgery or diabetes mellitus, for example, show a reduced level of response to sildenafil (eg 40-60%). [6][7][8] Approximately 50% of men who receive a prescription for sildenafil discontinue use of the drug over time. 9 Among other factors, side effects such as headache, flushing and changes in color vision are often cited as reasons for discontinuation of use.…”