Editing Pathophysiology of Erectile Dysfunction (section)

==== Vascular ====

* '''Arteriogenic'''
** '''<span style="color:#ff0000">Most common underlying mechanism of organic ED</span>'''
** '''<span style="color:#ff0000">Risk factors:</span>'''
**# '''<span style="color:#ff0000">Age</span>'''
**# '''<span style="color:#ff0000">Diabetes mellitus</span>'''
**# '''<span style="color:#ff0000">Dyslipidemia</span>'''
**# '''<span style="color:#ff0000">Hypertension</span>'''
**# '''<span style="color:#ff0000">Obesity</span>'''
**# '''<span style="color:#ff0000">Metabolic syndrome</span>'''
**# '''<span style="color:#ff0000">Sedentary lifestyle</span>'''
**# '''<span style="color:#ff0000">Smoking</span>'''
**# '''<span style="color:#ff0000">Blunt perineal or pelvic trauma</span>'''
**# '''<span style="color:#ff0000">Pelvic irradiation</span>'''
** '''Atherosclerotic or traumatic arterial occlusive disease''' can decrease perfusion pressure and arterial flow to the sinusoidal spaces, increasing time to maximal erection and decreasing the rigidity of the erect penis
***In most patients with arteriogenic ED secondary to atherosclerosis, the impaired penile perfusion is a component of the generalized atherosclerotic process.
** Lesions in the pudendal arteries are much more common in ED men than in the general population of similar age.
** Cardiovascular disease is associated with ED. Because the size of the penile artery is smaller compared with coronary arteries, the same level of endothelial dysfunction causes a more significant reduction of blood flow in erectile tissues compared with that in coronary circulation
*** '''The degree of ED strongly correlates with severity of cardiovascular disease;''' recent studies suggest that '''ED may be considered a sentinel marker in men with occult cardiovascular disease'''
*** Remains controversial whether a diagnosis of ED alone should initiate a more thorough cardiovascular evaluation§
** '''In hypertension, the increased blood pressure itself does not impair erectile function; rather, the associated arterial biochemical and structural changes are thought to be the causes; a narrowed lumen or increased wall/lumen ratio in the arteries contributes to increased peripheral vascular resistance in hypertension.'''
** Cigarette smoking may induce vasoconstriction and penile venous leakage because of its contractile effect on the cavernous smooth muscle; second-hand smoke exposure is associated with a small, statistically insignificant increase in risk of ED
** High body weight, BMI, and total body fat percentage are independently associated with greater prevalence of moderate to severe and complete ED.
** Long-distance cycling is also a risk factor for vasculogenic and neurogenic-ED. ED does not commonly occur in men who engage in recreational bicycle riding
* '''Cavernous (venogenic)'''
** '''Veno-occlusive dysfunction''' (failure of adequate venous occlusion)
*** '''Has been proposed as one of the most common causes of vasculogenic impotence'''
*** '''May result from various pathophysiologic processes, including:'''
**** '''Degenerative tunical changes'''
**** '''Fibroelastic structural alterations'''
**** '''Insufficient trabecular smooth muscle relaxation'''
**** '''Venous shunts'''
** Degenerative changes (e.g., Peyronie disease, old age, and diabetes) or traumatic injury to the tunica albuginea (e.g., penile fracture) can impair the compression of the subtunical and emissary veins.