arteriovenoosista

Arteriovenoosista, also known as arteriovenous or AV, refers to a connection or shunt between an artery and a vein. Normally, arteries carry oxygenated blood away from the heart under high pressure, and veins carry deoxygenated blood back to the heart under lower pressure. An AV connection bypasses the capillary network, which is the normal site of exchange between blood and tissues. This can occur naturally or as a result of a medical condition or procedure.

Congenital arteriovenous malformations (AVMs) are abnormal tangles of blood vessels that can form during fetal development. These can occur in various parts of the body, including the brain, lungs, and limbs, and may cause symptoms depending on their location and size. Acquired AV fistulas, on the other hand, are often caused by trauma, such as penetrating injuries, or can be intentionally created for medical purposes. For example, an arteriovenous fistula is surgically created in the arm to provide access for hemodialysis in patients with kidney failure.

The presence of an AV connection can lead to several physiological changes. Blood flows from the high-pressure arterial system directly into the lower-pressure venous system, which can cause the affected veins to enlarge and thicken. This abnormal flow can also steal blood from surrounding tissues, potentially leading to ischemia or other complications. Symptoms vary widely and may include pain, swelling, changes in skin temperature or color, and in the case of cranial AVMs, neurological deficits or bleeding. Diagnosis typically involves imaging techniques such as ultrasound, CT angiography, or MRI. Treatment depends on the type, location, and symptoms of the AV connection and may range from observation to surgical intervention or endovascular embolization.