Color-coded duplex sonography in impotence: significance of different flow parameters in patients and controls

The use of color-coded duplex sonography of the cavernous arteries in the assessment of arteriogenic impotence was evaluated in 70 consecutive men referred for erectile dysfunction. Controls were 16 of the men with an unequivocal nocturnal penile tumescence and rigidity. After intracavernous injection of prostaglandin E1, peak flow velocity was 26.8 +/- 12.5 cm/s in patients and 37.2 +/- 13.0 cm/s in controls (p less than 0.05). 50% of the patients, but none of the controls, had peak flow velocities of less than 20 cm/s in at least 1 cavernous artery. However, within the range of 20-40 cm/s, there was marked overlap between groups. The mean flow velocity and resistance index did not improve the discriminative value of peak flow velocity. Peak flow velocity after intracavernous injection of vasoactive drug enables the discrimination between impotent patients and controls. In a single patient, however, particularly one with a flow velocity of 20-40 cm/s, definition of arteriogenic impotence remains difficult.