Arterioventrális

Arterioventrális refers to a connection or passage between an artery and a vein. This bypasses the typical capillary network, which is where the exchange of oxygen and nutrients from the blood to tissues and the removal of waste products occurs. Arterioventricular shunts, also known as arteriovenous fistulas when abnormal, can be congenital or acquired. Congenital arteriovenous malformations are present at birth and can range in severity. Acquired fistulas can result from trauma, surgery, or certain medical conditions. In some physiological contexts, such as in the skin, arterioventricular anastomoses (a type of shunt) play a role in thermoregulation, allowing blood to bypass the superficial capillaries to conserve heat or to dissipate heat by increasing blood flow near the surface. The presence of an arteriovenous shunt can lead to several physiological consequences. Blood flows from the higher pressure arterial system directly into the lower pressure venous system, causing the vein to dilate and its walls to thicken due to increased blood flow and pressure. This can also lead to reduced blood flow to the tissues downstream of the shunt. In some cases, particularly with large shunts, the heart may have to work harder to maintain adequate circulation, potentially leading to heart failure. Diagnosis typically involves imaging techniques such as ultrasound, CT angiography, or MR angiography. Treatment depends on the size, location, and symptoms associated with the shunt and may involve minimally invasive procedures like embolization or surgical intervention.