Hemodynamic characterization of a functional erection - Arterial and corporeal veno-occlusive function in patients with a positive intracavernosal injection test

Objectives: To characterize hemodynamically a functional/rigid erection and study the hypothesis that a positive intracavernosal injection test indica tes normal arterial and corporeal veno-occlusive function. Methods: 33 pati ents (mean age 39.5 +/- 9 years), who developed rigid erection during pharm acocavernosometry, included in the present study. The presence of axial rig idity was determined at steady state equilibrium intracavernosal pressure, by absence of buckling to axial force of 1 kg, applied to the erect penis a nd sustained for greater than or equal to 15 min. Arterial and veno-occlusi ve hemodynamic parameters were analyzed. Results: Flow-to-maintain at intra cavernosal pressure 150 mm Hg and mean pressure decay values ranged between 0.5-13 ml/min and 5-85 mm Hg, respectively. Flow-to-maintain values >5 ml/ min were noticed in 8 patients (24.24%), while pressure decay values >45 mm Hg in 13 patients (39.39%). Pharmacocavernosography revealed moderate opac ification of venous structures in 7 cases (21.21%). Abnormal systemic-caver nosal systolic arterial pressure gradients in both cavernosal arteries were noticed in 9 patients (27.27%). All patients with flow-to-maintain values >5 ml/min had normal arterial function. Conclusions: A functional/rigid ere ctile response may coexist with arterial insufficiency or corporeal veno-oc clusive dysfunction. Presence of normal or borderline arterial inflow may c ompensate minimal or moderate veno-occlusive dysfunction, resulting in a fu nctional - but not normal - erection. Such information is critical when the intracavernosal injection lest is used For diagnostic purposes.