Objectives. To assess the contribution of a second injection of vasoactive medication into the corpus cavernosum during the duplex Doppler study for evaluation of young patients with vasculogenic erectile dysfunction (ED). Methods. Thirty-five patients, 23 to 50 years old (median age 43), clinically diagnosed as having venoocclusive ED underwent a color duplex Doppler study. The peak systolic velocity, end-diastolic velocity, resistance index, and arterial diameter measurements were obtained from both cavernosal arteries before and 2, 5, 10, and 20 minutes after an intracavernous injection of a vasoactive drug. All patients were reinjected with similar doses of the same medication, and all measurements were repeated. The erection duality was estimated 20 minutes after each injection. Results. The peak systolic velocity after the second injection was significantly higher statistically than after the first injection (P <0.02). No differences in end-diastolic velocity, resistance index, arterial diameter, or the evaluated side between the first and second injections were found. Conclusions. A single injection of vasoactive drugs can provide sufficient information on the arterial and veno-occlusive mechanism during color duplex Doppler evaluation of young patients with vasculogenic ED without compromising the quality of the evaluation. Limiting the number of injections to only one may prevent adverse reactions caused by the second injection and reduce the cost and duration of this test. UROLOGY 55: 927-930, 2000. (C) 2000, Elsevier Science Inc.
