Duplex Doppler sonography of the flaccid penis: potential role in the evaluation of impotence.

Abstract

Duplex Doppler sonography of the cavernosal arteries of the penis with intracavernous injection (ICI) of vasoactive agents has been widely used to evaluate arterial insufficiency in impotence. Our goal was to assess the potential value of peak systolic velocity (PSV) measurements on the flaccid penis in the diagnosis of arteriogenic impotence. Forty-four men underwent duplex Doppler sonography with PSV measurements before and after ICI of prostaglandin E(1). Three different cutoff values for lowest normal PSV before injection-5 cm/second, 10 cm/second, and 15 cm/second-were tested. Thirteen patients had arteriogenic insufficiency based on post-ICI duplex sonography and clinical response. Results for our different cutoff PSV values of 5 cm/second, 10 cm/second, and 15 cm/second in diagnosing arteriogenic impotence were, respectively: sensitivity 29%, 96%, and 100%; specificity 100%, 92%, and 23%; negative predictive value 80%, 92%, and 100%; positive predictive value 100%, 81%, and 41%; and overall accuracy 79%, 93%, and 44%. In the flaccid state, there was a significant difference in mean PSV between the "normal" group (12.6 +/- 0.9 cm/second) and the arteriogenic impotence group (7.7 +/- 1.1 cm/second). Twenty-nine patients with a bilateral PSV of 10 cm/second or less before ICI had a normal clinical response. A cutoff PSV value of 10 cm/second in the flaccid state had the best accuracy in predicting arterial insufficiency. Duplex Doppler sonography is proposed as the initial test to evaluate the penile arterial supply and to determine whether patients are good candidates for therapy with ICI.