Timing of Penile Color Flow Duplex Ultrasonography Using a PGE1

Choi, Seong; Jeong, Yeon Tae; Kim, Jong Min; Rhew, Hyun Yul

Abstract

Duplex ultrasonography (USG) is an accepted method to assess noninvasively arterial inflow to the penis. Optimal pharmacological agents as well as timing of the scan and stimulation during the scan continue to be debated. Between August 1994 and May 1996, 24 normal males (control group) and 45 impotent patients (impotence group) underwent penile doppler sonography, and their records were reviewed. Scans were performed at 1, 3, 5, 10, 15, 20 and 30 minutes after intracavernous injection of PGE1 (10 pg) in all subjects. Any subject not having a full erection at 15 minutes performed private self-stimulation for at least 5 minutes before the 30 minute scan. If we define normal arterial inflow as a peak systolic velocity (PSV) of 30 cm. per second or greater in the best artery, 46% of control group and 55% of impotence group achieved this velocity until 5 minutes. One (4%) of control group and three (6%) of impotence group achieved maximum velocity at 1 or 3 minutes but continually PSV of 30 cm. per second or greater after 5 minutes, so any subject may not have had an incorrect diagnosis. When we calculated maximum velocity in the best artery in relation to percentage tumescence, maximum velocity were recorded most often at 10% tumescence (46% of control group and 51% of impotence group). If we define normal arterial inflow as PSV of 30 cm. per second or greater in best artery, the cumulative percentage of patients who achieved this velocity at 1, 3, 5, 10, 15, 20 and 30 minutes were 4, 34, 46, 88, 96, 96 and 100% in control group and 6, 28, 55, 90, 92, 94 and 96% in impotence group. In conclusion, we support delaying the initial scan until 5 minutes, performing the additional scans until 30 minutes and self-stimulation when necessary. We believe all efforts should be made to have studies performed in the setting of least anxiety to the patient.