The noninvasive diagnosis of vasculogenic impotence

One hundred eleven impotent men and 25 potent men were prospectively evaluated with a standardized exercise treadmill test (SETT) used to noninvasively define their pelvic hemodynamics. Fifty-six men had vasculogenic impotence, whereas the remaining 55 had erectile dysfunction resulting from undetermined causes (31), psychogenic factors (10), or other identifiable reasons (14). Arteriography was performed on 40 (71%) of the patients with vasculogenic impotence without false positive results, as well as in 11 (44%) of the potent control patients and in six (11%) of the patients with nonvasculogenic impotence without false negative results, confirming the validity of the SETT. The distinction between vasculogenic and nonvasculogenic impotence can be accurately made with the SETT. Patients with vasculogenic impotence had a resting penile-brachial index (PBI) equal to 0.60 ± 0.022 (mean ± SEM) and a PBI after exercise equal to 0.45 ± 0.019 with a fall in the mean PBI of -0.15 (p < 0.001). Patients with nonvasculogenic impotence had a resting PBI equal to 0.80 ± 0.024 and a PBI after exercise equal to 0.88 ± 0.019 with a rise in mean PBI of 0.08 (p < 0.001). This response was not significantly different between the control group and the nonvasculogenic impotence patients. The addition of PBI determinations after treadmill exercise revealed that 18% of the patients with vasculogenic impotence would have been incorrectly diagnosed, because their resting PBI was greater than the traditional standard of 0.70. Furthermore, 18% of the patients with nonvasculogenic impotence would have been incorrectly diagnosed as having vasculogenic impotence because their resting PBI was less than 0.70. The determination of the PBI before and after SETT is a previously undescribed technique that increases accuracy in the noninvasive diagnosis of vasculogenic impotence.