Arteriovenous malformation

An arteriovenous malformation ( AVM) is a congenital malformation of blood vessels, are directly connected to veins in the arteries, without intervening capillaries. AVM belong to the vascular anomalies. In older literature, the AVM is often considered one of the angioma, however, is not a tumor-like growth.

Anatomy

The vascular malformation consists of a network of direct connections between the hepatic arteries and the veins blutabführenden, with an exact delimitation in the area of ​​AVM no longer is often possible. Due to the increased blood flow within the AVM, the blood vessels are dilated. Due to the optical structure of a malformation AVM AVM is also described as glomeruli, just below the skin surface may be visible as a spiral wire braid. The center of the seemingly tangled blood vessels is referred to in medicine as a nidus (Latin for "nest" ) or shunt ( English for " short connection").

Histologically, the structure of the blood vessels in the AVM is different from the "healthy" blood vessels. Within the AVM some layers of the wall of the arteries / veins are extremely thin or absent. The blood vessels of the AVM are therefore more prone to rupture, which can lead to ( internal ) bleeding.

The size of an AVM is variable, the extent of the AVM may change with time both increase and decrease.

In the area of ​​arteriovenous malformation and aneurysms may be present.

Demarcation

Arteriovenous malformations are arteriovenous fistulas as direct connections between arteries and veins. Arteriovenous fistulas are usually but not innate and can be caused by damage to the arteries and veins lie close together or generated artificially to treat diseases.

Localization

Arteriovenous malformations can occur throughout the body and have different symptoms and effects.

  • Cerebral AVM in or on the brain can cause a stroke and are therefore the most risky type
  • Cranial AVM on the skull
  • Spinal AVM in the spinal canal and spinal cord can cause paralysis
  • Pulmonary AVM within the lung can cause cyanosis and abscesses, see also Osler
  • AVM within muscle tissue can cause hypotonia and joint pain
  • AVM in the eye and retina, see Bonnet- Dechaume -Blanc syndrome
  • AVM in the extremities
Artery Arthralgia Bonnet–Dechaume–Blanc syndrome Medical guideline
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