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Guilherme Mazui

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What is the Difference Between AVM and AVF?

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The main difference between an arteriovenous malformation (AVM) and an arteriovenous fistula (AVF) lies in their location and structure. Both AVMs and AVFs are abnormal connections between arteries and veins, but they differ in the following aspects:

  1. Location: AVMs are found within the tissue of the brain or spinal cord, while AVFs are found in the coverings of the brain or spinal cord, such as the dura mater or arachnoid.
  2. Structure: AVMs are characterized by a complex, tangled web of arteries and veins, whereas AVFs involve a direct, simple connection between an artery and a vein, bypassing the normal capillary bed.

Both AVMs and AVFs can cause serious problems, such as increased pressure in the venous system, leading to nervous system dysfunction, seizures, and hemorrhage. Diagnosis of these conditions typically involves imaging techniques like cerebral angiography, magnetic resonance angiography (MRA), and venography (MRV). Treatment options depend on the patient's age, overall health, and the size and location of the AVM or AVF, and may include surgical removal, endovascular embolization, or stereotactic radiosurgery.

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  • What is the Difference Between AVM and AVF?
  • Comparative Table: AVM vs AVF

    • Comparative Table: AVM vs AVF

    Here is a table comparing the differences between Arteriovenous Malformations (AVM) and Arteriovenous Fistulas (AVF):

    Feature AVM AVF
    Definition AVM is a vascular malformation that occurs within the tissue of the brain or spinal cord, where the capillaries that normally exchange blood between arteries and veins are bypassed, causing blood to flow quickly and directly from the arteries into the veins. AVF is an abnormal connection between an artery and a vein, which can occur anywhere in the body but is mostly found in the head, neck, spine, and liver.
    Formation AVMs are generally congenital, meaning they are present from birth. AVFs can be both congenital and acquired, such as through trauma.
    Structure AVMs consist of multiple tortuous feeding arteries, a nidus composed of tortuous vascular channels connecting arteries, and draining veins without a capillary network. AVFs have a direct and simple connection between an artery and a vein, bypassing the normal capillary bed.
    Blood Flow AVMs are classified as high-flow lesions due to the rapid blood flow within them. AVFs are also considered high-flow lesions because of the fast blood flow within the shunt.
    Symptoms AVMs may not show any signs or symptoms until they rupture, resulting in bleeding in the brain (hemorrhage). In people without hemorrhage, symptoms can include seizures, headaches, and neurological deficits. AVFs may cause symptoms such as high blood pressure, heart failure, and leg swelling, depending on the location of the fistula.
    Treatment Treatment for AVMs may include observation, surgery, endovascular embolization, or stereotactic radiosurgery. Treatment for AVFs may involve surgery to repair the abnormal connection or endovascular procedures to close the fistula.
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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.