Evaluation of vasculogenic impotence using dynamic penile washout test.

Two control volunteers and 8 impotent patients entered this study for evaluation of arterial function and venous competence of the corpus cavernosum. The skin and corporeal xenon-133 (Xe-133) penile washout tests were conducted on each person before and 5 and 60 minutes after an intracavernous injection of prostaglandin E1. The half-time clearance (T 1/2) and blood flow (Q) were used for evaluation. The parameters of the skin washout test obtained from impotent patients changed from T 1/2 = 14.3 +/- 6.2 minutes, Q = 3.75 +/- 2.56 ml/100g tissue/minute preinjection to T 1/2 = 5.23 +/- 1.78, Q = 9.96 +/- 2.69 at 5 minutes post-injection and T 1/2 = 3.89 +/- 0.86, Q = 12.9 +/- 3.0 at 60 minutes post-injection, p less than 0.01; while the corporeal washout test changed from T 1/2 = 84.6 +/- 107.1 minutes, Q = 2.91 +/- 3.17 ml/100g tissue/minute to T 1/2 = 41.2 +/- 99.6, Q = 10.6 +/- 9.7 and T 1/2 = 13.9 +/- 16.2, Q = 7.78 +/- 6.35, p less than 0.05, respectively. The flow ratio (post-injection/pre-injection) was 1.01-6.04 at 5 minutes and 1.39-8.01 at 60 minutes later in the skin washout test, and 1.07-72.2 at 5 minutes and 0.60-45.7 at 60 minutes in the corporeal washout test. However, the individual variations were considerable. This study suggests that the Xe-133 penile washout test after an intracavernous injection may help in demonstrating the hemodynamics of the cavernosal arteries and dorsal arteries, and in evaluating the severity of penile vascular impairment. Moreover, the flow ratio may reflect vascular compliance; the higher the ratio, the better the compliance.(ABSTRACT TRUNCATED AT 250 WORDS)