Sexual impotence caused by vascular disease: diagnosis with duplex sonography

We used duplex Doppler sonography to assess the hemodynamic function of the penis in patients with impotence to determine if there is arterial disease or if the veins are incompetent. The penis was scanned in the flaccid state, then again after erection was induced by intracorporal injection of papaverine. The diameter of each cavernosal artery was measured before and after injection and, by using Doppler sonography, the maximal systolic velocity in each cavernosal artery was measured. The Doppler gate was placed over the dorsal vein to detect any flow in that vein signifying venous leakage. The Doppler gate then was placed over the cavernosal veins in an attempt to detect cavernosal venous incompetence. Forty-five men with impotence were included in the study. In 39 patients, the cause of impotence was confirmed by other studies. The diameter of the cavernosal arteries and the increase in diameter of these arteries after induction of an erection were similar in all diagnostic groups. The peak systolic velocity, however, was decreased in patients with arterial insufficiency as compared with the velocity in normal subjects. In normal subjects, the mean peak velocity was 47 +/- 9 cm/sec; in patients with mild to moderate arterial insufficiency it was 35 +/- 16 cm/sec; in patients with severe arterial insufficiency it was 7 +/- 8 cm/sec. The difference in peak velocities between the right and left cavernosal arteries after papaverine injection (asymmetric arterial response) was significantly larger in patients with mild to moderate arterial insufficiency than in other diagnostic groups. Four patients with venous incompetence had detectable flow in the dorsal vein, but no flow could be detected with Doppler sonography in the cavernosal veins in any patients, including those who were proved to have significant cavernosal venous leaks. Our findings suggest that Doppler measurement of maximal systolic velocity in the cavernosal arteries after papaverine injection is an accurate indicator of arterial function. Asymmetric flow in the cavernosal arteries also suggests some degree of arterial insufficiency. Diameters of the cavernosal arteries and their increase after injection are not predictive of arterial patency. Doppler sonography cannot show cavernosal venous leakage, but in some cases it can show dorsal venous incompetence.