Retrospective review of flow patterns following retropubic prostatectomy

We retrospectively evaluated penile inflows in 103 previously potent individuals who underwent standard nerve sparing radical retropubic prostatectomy (RRP) for the treatment of prostate cancer. No effort to identify or spare the accessory pudendal artery (APA) was made in any case. Our goal was to investigate the role of the accessory internal pudendal artery (APA) in the maintenance of erections in this population. We hypothesize that if the APA is present in a significant number of men, and its ligation significantly contributes to post-RRP impotence, then there should be an increased incidence of asymmetry between R/L cavernous arterial flows among post RRP patients with vascular impotence.

One hundred and three previously potent individuals complaining of persistent erectile dysfunction for at least six months after RRP were studied with color duplex Doppler, following age specific dosing of PGE1. Vascular assessment was performed before and after self-stimulation, measuring peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI). Erections were visually rated as inadequate (INA), adequate (ADE) for penetration, or excellent (EXC) with sustained rigidity for at least 20 min. Cavernous artery asymmetry (CAA) was defined as a >10 cm/s difference between right and left sided arterial flows.

Mean duration between surgery and Doppler study was 14.7 months. 27 out of 103 (26%) of patients developed excellent rigidity consistent with isolated neurogenic impotence (PSV=32.0 cm/s, mean RI=0.95); 24 out of 103 (23%) had adequate vascular responses making it impossible to infer presence or absences of neurogenic impotence; 52 out of 103 (51%) had inadequate rigidity consistent with vascular insufficiency (PSV=23.7 cm/s, mean RI=0.66). We noted that of patients with EXC response, 48% (13 out of 27) had CAA. Among patients with severe inflow disease (INA responders), CAA was seen in only 21% of cases (11 out of 52).

The incidence of APA has been reported as being from 4-70%, and its significance in the maintenance of erections has been questioned. Assuming that the APA provides significant inflow in some patients, we expected an increase in CAA in individuals in whom it was sacrificed. We found a higher incidence of CAA among post-RRP patients with normal vascular erectile responses to PGE1 (48%) compared to men with true vasculogenic impotence post-RRP (21%). These data do not support the importance of the APA in the maintenance of erections in the post-RRP patient.