Diagnosis of vasculogenic impotence: Combination of penile xenon-133 washout and papaverine tests

The present study evaluates both penile xenon-133 washout (XWT) and papaverine tests (PT) in the diagnosis of vasculogenie impotence. XWT was accomplished by subcutaneous injection of xenon-133 (1-2 mCi in 0.1 mL saline solution) into the dorsal coronal prepuce. Abnormal XWT was suggested in patients whose clearance time (T 1 2) was longer than 7.5 minutes and whose penile blood flow rate (Q) was less than 6 mL/100 g tissue/min. PT was done by intracavernous injection of papaverine (60 mg in 20 mL normal saline). Abnormal PT was indicated in patients whose onset of full erection was more than ten minutes after papaverine injection and whose duration of erection was less than one hour. Ten young and 11 older normal volunteers were examined with XWT only; all showed normal results. A total of 60 impotent patients were examined with both XWT and PT and were classified into four groups: in 2 patients (3.3 %) both XWT and PT were normal (group 1); in 8 (13.3 %) XWT was abnormal and PT normal (group II); in 14 (23.3 %) XWT was normal and PT abnormal (group III); and in 36 (60 %) both XWT and PT were abnormal (group IV). On further examination with bilateral hypogastrie arteriography in 10 XWT-abnormal patients and on surgical correction of abnormal curvature in 5 XWT-abnormal patients, all (100%) were proved to have penile arterial insufficiency. Erection cavernosography performed in 15 PT-abnormal patients confirmed penile venous insufficiency in 80 percent. We conclude both XWT and PT are simple and effective for evaluation of the penile arterial blood flow and venous competence, respectively. In addition, combination of XWT and PT would be essential for a more reliable diagnosis of vasculogenic impotence.