In 10 formalin-preserved adult male cadavers, dissection of the penile veins, arteries and nerves revealed information of clinical importance. The main venous drainage of the corpora cavernosa is via the cavernous veins, with additional drainage through the circumflex, deep dorsal, and crural veins. The arterial supply of the cavernous bodies varied remarkably, and the incidence of an accessory internal pudendal artery was high. The cavernous nerves, previously believed to be microscopic structures, were in fact identifiable grossly, and we were able to follow them from the region of the hilum of the penis to the prostate. The nature of these nerves was then confirmed by serial histologic sectioning. This detailed knowledge of the venous drainage and arterial and nervous supply of the penis, as well as of the relationships among the cavernous structures in the hilum of the penis, can elucidate the cause of erectile dysfunction and provide a valuable guide for surgical correction of vasculogenic and neurogenic impotence.

No abstract

We designed two animal experiments to elucidate the effect of obstruction of the internal pudendal artery on erectile function. In five dogs the internal pudendal or penile artery was acutely clamped unilaterally or bilaterally with a non-crushing vascular clamp. In eight dogs, the internal pudendal or penile artery was ligated, unilaterally or bilaterally, and occlusion was maintained for two months. In both models, electrodes were implanted around the cavernous nerves for electroerection. In unilateral occlusion, blood flow in the contralateral internal pudendal artery was recorded via an ultrasonic probe. In both unilateral and bilateral occlusion, intracavernous pressure in both corpora cavernosa was recorded through a 21-gauge butterfly needle connected to a Statham transducer. In the chronic model, selective pudendal angiography was done after the erection study was completed; the dogs were then sacrificed and the penile tissue was examined histologically under light microscopy. Unilateral acute clamping of the internal pudendal or penile artery caused a compensatory increase in arterial flow in the contralateral pudendal artery with only moderate impairment of intracavernous pressure on the ipsilateral side, but bilateral occlusion resulted in a marked reduction in the intracavernous pressure response to neurostimulation. In contrast, chronic obstruction of penile vessels had a minimal effect on erectile function due to the development of a rich network of collaterals around the penis. Histological evaluation revealed mild local changes in the cavernous tissue with characteristic compensatory enlargement of branches of the cavernous artery on the control side in cases of unilateral occlusion.

The diagnostic usefulness of nocturnal penile tumescence monitoring, penile-brachial index and intracorporeal injection of papaverine (60 mg. in 20 ml. normal saline) was compared in 43 impotent men. Intracorporeal pressure was measured with a pressure transducer. Based on turgidity, and the time of onset and duration of erection, we classified the impotence as psychogenic/neurogenic (normal vascular competence), mild or severe arteriogenic, or venogenic. The intracorporeal injection of papaverine was useful as a functional diagnostic test for impotence. The penile-brachial index, an indirect measurement of the flaccid penis, did not correlate well with the results of the papaverine test. A poor response to papaverine injection documents organic impotence and, under these circumstances, nocturnal penile tumescence monitoring is not necessary. We conclude that the intracorporeal injection of papaverine currently is the best screening technique for the differential diagnosis of vasculogenic impotence.

Intra-abdominal cryptorchidism and infertility are universal features of the prune belly syndrome but they usually are not seen with posterior urethral valves. To understand further the differences between these patients we reviewed testicular histology in 5 fetuses from each of 3 groups: prune belly syndrome, posterior urethral valves and normals. Spermatogonia were noted in all but the numbers were significantly reduced in those with the prune belly syndrome and posterior urethral valves compared to normals: 8.6 and 13.4 versus 31.2 per 10 high power fields, respectively. The fetuses with the prune belly syndrome also had marked Leydig cell hyperplasia in contrast to the other groups. These findings suggest that the testicular pathological condition in patients with the prune belly syndrome is caused by more than mechanical cryptorchidism.