Does the positive intracavernous papaverine test always indicate a normal penile vascular system?

A positive intracavernous papaverine test has been presumed to determine normal erectile hemodynamics. Recently, positive erectile responses to intracorporeal injection tests were reported in patients with penile arterial insufficiency.

This hypothesis was assessed by obtaining hemodynamic data using color Doppler ultrasonography in 417 patients with erectile dysfunction aged between 20 and 73 years (mean 43.06 +/- 13.66). A normal penile vascular system was found in 95 patients (22.79%), veno-occlusive dysfunction in 76 (18.22%), arteriogenic erectile dysfunction (ED) in 113 (27.10%) and mixed-type ED in 133 (31.89%).

A positive erection response was achieved in 176 patients with combined intracavernosal injection of 60 mg papaverine and self-manual genital stimulation (CIS) test, while a negative response was observed in the remaining 241 (57.79%). Color Doppler ultrasonography combined with pharmacological erection has proved a normal penile vascular system in 94 (53.41%) and penile arterial insufficiency in 82 (46.59%) patients of those who gave a positive response to the CIS test. Also, a positive CIS test response was observed in all patients with unilateral arterial insufficiency (n = 31) and in 51 patients (62.19%) out of 82 with bilateral arterial insufficiency.

A positive intracavernous papaverine test indicates veno-occlusive dysfunction competence but does not necessarily signify a normal penile arterial system. The CIS test should be combined with color Doppler ultrasonography in order to determine the vascular component of ED, since the differentiation is not possible between slight penile arterial insufficiency and psychogenic or neurogenic impotence with the CIS test.