The causes of erectile dysfunction (ED) can be divided into two general categories: organic erectile dysfunction and psychogenic.
Among the organic causes of erectile dysfunction are those conditions that physically impair the delivery of adequate blood flow to, or prevent maintenance of sufficient blood within, the erectile tissue of the penis. These organic causes of erectile dysfunction can further be divided into vascular and neurologic reasons.
As much as 90% of ED is accounted for by organic causes.
Vasculogenic ED consists of arterial insufficiency and venous leak syndrome. Arterial insufficiency is where insufficient arterial blood is pumped to the penis, and venous leak syndrome is where that arterial blood pumped to the penis following sexual stimulation is inadequately trapped in the erectile tissue of the penis for a sufficient period of time to permit a satisfactory erection. In either case, the vascular system responsible for either achieving or maintaining an erection is dysfunctional.
Vasculogenic ED can be caused by hypertension, diabetes and heart disease that atherosclerosis or congestive heart failure may impose. Any of these conditions can compromise the delivery of blood necessary to achieve an erection. As vascular injury develops in the larger arteries like the heart or the neck, the risk of heart attack and stroke increases. Indeed, erectile dysfunction often represents “the canary in the coal mine,” manifesting an early symptom of peripheral artery disease that may portend a more life-threatening condition.
Venous leak syndrome is caused by any condition that changes the architecture of the penile erectile tissue preventing compression of the small veins that return the erectile blood from the penis back into the general circulation resulting in loss of erection. Chronic conditions such as diabetes or the fibrotic changes that eventually develop in the elastic erectile tissue of the penis that fails to expand from sufficient arterial blood flow can also cause venous leak syndrome.
Indeed, the acute event of radical prostatectomy for prostate cancer will immediately cause lasting erectile dysfunction in as many as 60% of patients without preoperative ED. This is due to penile cavernosal nerve injury preventing the release of nitric oxide responsible for arterial dilation and increased penile arterial blood flow. This explains why medication like Viagra™ and Cialis™ are ineffective in treating ED caused by neurologic injury. If not mitigated by vasoactive penile injection rehabilitation, this acute neurologic event will lead to chronic penile architectural changes causing venous leak syndrome that often can’t be effectively treated by injections or any other non-surgical treatment options. Without release of nitric oxide from damaged penile cavernosal nerve endings, medication that delay its breakdown have no influence on penile blood flow. In these patients, only penile prosthesis (penile implant) placement will correct the ED.
Together, the vasculogenic sources of arterial insufficiency and venous leak syndrome, and the neurologic causes from prostate, pelvic surgery or other diseases affecting the peripheral nervous system such as advanced diabetes, represent organic erectile dysfunction.
As much as 90% of ED is accounted for by organic causes. The remaining 10% of ED is considered non-organic, or psychogenic. Anxiety, depression, fear, pain or medications used to treat psychological conditions can all result in psychogenic ED. In addition to a thorough medical history and physical examination, penile duplex ultrasonography may be required to distinguish between organic and psychogenic causes of one’s ED and identify definitively the most appropriate erectile dysfunction treatment option.
The general adult and prosthetic urology practice of Robert J. Cornell, MD, PA, is especially adept at achieving not only a definitive diagnosis of the type of ED you’re experiencing, but can offer a durable solution for each of these conditions regardless of the cause.
This physician is a Boston Scientific consultant but was not compensated for the creation of this article.