Pathophysiology of erectile dysfunction

Pathophysiology of erectile dysfunction

Given the complexity of the system, it is not surprising that a wide variety
of diverse disorders may result in erectiledysfunction (Table 1). Often, the
cause is multifactorial, but vasculogenic causes are the most commonly
implicated.

VASCULOGENIC CAUSES

Arterial insufficiency

Because the development and maintenance of a rigid erection depend on
achieving a high intracavernosal pressure, it is notsurprising that
disorders affecting the peripheral arterial blood flow are strongly associated
with erectile dysfunction (Table 2).The most common cause is atheroma
involving either the common or internal iliac arteries or their more distal
branches(Figure 28). The risk factors for this are similar to those for
coronary artery disease (including smoking, hypertension,hyperlipidemia,
diabetes mellitus and obesity). Narrowing or occlusion of the internal pudendal
arteries reduces perfusionpressure to the corpora, resulting in a failure to
achieve full rigidity. In the absence of such pressure, the normal
veno-occlusive mechanisms cannot operate and, thus, the problem is
compounded by secondary venous leakage. Obliterativedisease of the aorta may
also result in erectile dysfunction.

Venous leakage

In the presence of a normal arterial inflow, normal veno-occlusive mechanisms
should slow egress of blood from the corporato a virtual trickle during full
erection. Failure to do so results in a flaccid erection and leakage of blood,
either into the deepdorsal vein

Table 1 Risk factors for erectile dysfunction

Age_

Vascular factors

myocardial infarction

coronary artery bypass surgery

cerebral vascular accident

peripheral vascular disease

hypertension

hyperlipidemia

smokingMetabolic diseases

diabetes mellitus

renal failure

thyrotoxicosis

hypothyroidism

depression

alcoholism

chronic liver disease

adrenal disorders

hypogonadism