Lack of correlations between penile thermography and pelvic arteriography in 29 cases of erectile impotence

Current state of endovascular treatment for vasculogenic erectile dysfunction

Normal erectile function requires adequate penile arterial inflow, normal penile architecture and an intact venous capacitance system. Vascular disease is the dominant etiology of erectile dysfunction (ED) and current medical therapy increases penile blood flow. However, in a large proportion of patients, medical therapy is inadequate or contraindicated requiring the use of mechanical constrictive devices or implantation of a penile prosthesis. Rapid advances in endovascular intervention have allowed safe and effective treatment of small arteries in other vascular beds. A minimally invasive approach targeting penile arterial inflow disease may prove to be safe and effective. In this paper, we discuss the normal arterial blood supply to the penis, describe angiographic findings in patients with ED, and critically review the published data on endovascular and microsurgical approaches at reestablishing penile blood flow. Lastly, we offer a potential algorithm and procedural tips for endovascular intervention for ED.

Mechanisms of veno-occlusion within and outside the canine corpus cavernosum penis using a pressure-flow technique and cavernoso-venography

BACKGROUND

Physiological erection of the penis requires multiple mechanisms causing an increase in the arterial blood influx into, and decrease in the venous drainage out of the cavernous space.

METHODS

We investigated the extent and location of the venous occlusion that occurs with penile erection within (intrinsic mechanism) and outside (extrinsic mechanism) the corpus cavernosum penis, using 15 adult male mongrel dogs. Under controlled flows produced by a combination of aortic ligation and constant infusion of saline into the corpus cavernosum penis, or into the deep dorsal vein, pressures within the cavernous space or deep dorsal vein were measured before and after electrical stimulation of the pelvic splanchnic (pelvic nerve), the hypogastric, and pudendal nerve. An increase in pressure following nerve stimulations represented an increase in outflow resistance due to occlusion of the venous system. Pre-and post-stimulation radiologic evaluations were performed to determine the site(s) of venous occlusion.

RESULTS

Unilateral stimulation of the pelvic nerve caused leftward shift of the corporeal pressure-flow curve. Bilateral stimulation of the pudendal nerve caused a marked rise in deep dorsal vein pressure.

CONCLUSIONS

Both intrinsic and extrinsic venous occlusion mechanisms exist and that the former is activated primarily by unilateral stimulation of the pelvic nerve and the latter by bilateral stimulation of the pudendal nerve. The occlusion site for the extrinsic mechanism was localized to where the dorsal vein penetrates the muscles at the base of the pelvis, whereas the precise site for the intrinsic mechanism could not be determined.

Thermography as a diagnostic measure of vasculogenic impotence

There is no correlation between penile-brachial index (PBI) and thermography. While it has been shown to be of significant value in other areas of medicine, thermography is non-contributory to the diagnosis of vasculogenic impotence.

Comparison of neurothermography and contrast myelography

Eighty consecutive patients who first had an electronic infrared thermogram (neurothermogram) and a subsequent oil myelogram were studied retrospectively. All patients had cervical and/or lumbosacral radiculopathy for 90 days. Negative neurothermograms were predictive of negative myelograms in 93% of our series. Positive neurothermograms were predictive of positive myelograms in 71% of the patients. The neurothermogram is not a specific test for intraspinal axis lesions as a cause of radiculopathy. Proximal neuropathic lesions of other causes will also produce abnormalities of the sympathetic autonomic (peripheral) nervous system. The major pathophysiologic findings detected by neurothermograms are complimentary to the EMG, NCVS, and late response techniques. Neurothermography was successful in predicting the outcome of myelography in 82% of patients in this study.