Arteriellvenösa

Arteriellvenösa refers to the direct connection between an artery and a vein, bypassing the usual capillary network. This abnormal communication is known as an arteriovenous fistula (AVF) when it is acquired, or an arteriovenous malformation (AVM) when it is congenital. Normally, oxygenated blood flows from arteries to capillaries, where gas and nutrient exchange occurs with tissues, and then returns to veins. In an AVF or AVM, blood shunts directly from the high-pressure arterial system into the low-pressure venous system. This can lead to several consequences. The affected veins experience increased blood flow and pressure, which can cause them to dilate and become tortuous, potentially leading to venous insufficiency, thrombosis, or rupture. The tissues downstream from the fistula may receive less blood flow due to the diversion of arterial blood, potentially causing ischemia. Symptoms vary depending on the location and size of the AVF or AVM, and can include visible bulging veins, pain, swelling, temperature changes, or even signs of heart failure if the shunt is large enough to significantly increase the workload on the heart. Diagnosis often involves imaging techniques such as Doppler ultrasound, CT angiography, or MRI angiography. Treatment aims to close or redirect the abnormal connection and can range from minimally invasive embolization procedures to surgical intervention.