Further Evidence of Venous Outflow Restriction During Erection

Abstract

To elucidate the effect of venous outflow restriction during erection, we studied eight dogs during artificial saline perfusion of the penis with and without neurostimulation to induce erection. With the infrarenal aorta clamped temporarily, saline infusion rates of 0.9 and 1.9 ml/min raised the mean intracorporeal pressure to 34 and 42 cm H2O, respectively, before stabilisation or return to baseline. When cavernous nerve stimulation was initiated, the mean intracorporeal pressure rose to 124 and 184 cm H2O (with infusion rates of 0.9 and 1.9 ml/min respectively) to induce full erection. Our results show that venous outflow restriction takes place during erection and that it is necessary not only to induce full erection but also to maintain it. Evaluation of venous competence is therefore essential during the investigation of impotence.

Possible Role for Acetylcholine as a Neurotransmitter in Canine Penile Erection

“…A significant reduc tion in arterial flow delayed the time required for the intracavernous pressure to attain maximal levels. The venous study during neurostimulation showed reduced cavernous outflow restriction after atropine, indicating less complete cavernous smooth muscle relaxation [ 15] than during neurostimulation without previous musca rinic blockade.…”

The Rationale for Pharmacologic Cavernosography

“…The non-opacification of the cavernous veins as a result of closed venous channels cannot be explained after this pressure drop merely by the passive squeezing of the emissary veins within the tunica albuginea 12 or by a passive compression of venous lacunae between the cavernous sinusoids and the tunica albuginea. 13 Our findings suggest an active venous occlusion mechanism which further histologic and elec tron microscopic studies are needed to identify.…”

Perineal floor efficiency in sexually potent and impotent men

“…Indeed, some electromyographic studies 1 appear to exclude any determinant role of both the ischiocavernous muscle (ICM) and bulbocavernous muscle (BMC) in the erection of the penis in younger men, supporting the idea that the vascular phase 2,3 and the characteristics of the human tunica albuginea 4 are able to guarantee enough intracavernous pressure for penetration. On the other hand, there is a considerable body of evidence in the literature that demonstrates an active role of the ICM in the initiation and maintenance of erection in humans 5±8 and in large mammals.…”