A POSITIVE INTRACAVERNOUS INJECTION TEST IMPLIES NORMAL VENOOCCLUSIVEBUT NOT NECESSARILY NORMAL ARTERIAL FUNCTION - A HEMODYNAMIC-STUDY

During impotence evaluations a positive intracavernous injection test has been presumed to signify normal erectile hemodynamics. This premis e was tested by obtaining hemodynamic data in 80 patients 17 to 65 yea rs old with positive injection tests: patients achieved maximal circum ference responses and equilibrium intracavernous pressures of 80 mm. H g or more (range 80 to 136) sustained for 30 minutes or longer. Corpor eal veno-occlusive testing revealed that flow-to-maintain (0.5 to 3 ml . per minute) and pressure decay (0 to 47 mm. Hg) values as well as ph armaco-cavernosography findings (absent or minimal contrast medium in venous structures in 92% of the cases) were all consistent with low ou tflow erection states. Arterial testing revealed right and/or left cav ernous systolic arterial blood pressures always at 80 mm. Hg or more, consistent with a prerequisite cavernous artery pressure value for a p ositive injection test. Systemic-cavernous systolic arterial blood pre ssure gradients were 0 to 24 mm. Hg, 25 to 34 mm. Hg and 35 mm. Hg or more in 47 (59%), 18 (22%) and 15 (19%) patients, respectively. Large systemic-cavernous pressure gradients suggested the presence of arteri al occlusive disease. In 8 patients with positive injection tests and gradients of 35 mm. Hg or more pharmaco-arteriography revealed hemodyn amically significant arterial occlusions. In conclusion, hemodynamic d ata in selected patients with positive injection tests revealed low ou tflow erection states, threshold cavernous artery pressures and dispar ities in systemic-cavernous systolic pressure gradients that suggested arterial disease in 19% of the cases. The erectile response in a posi tive test is equal to or greater than a threshold response, not always the maximum response as determined by the systemic blood pressure. A positive intracavernous injection test did not necessarily signify nor mal erectile hemodynamics.