Arteriovenous malformation

Arteriovenous malformations (AVM) are the defects in your vascular system. The vascular system includes veins, arteries, and capillaries. Veins help in carrying the blood back to the heart. Capillaries help in connecting the veins and arteries together. Arteries help in carrying blood away from the heart to other organs of the body. An AVM is a pile or tangle of arteries and veins. Pulmonary AVM consists of abnormal connections between the pulmonary arteries and pulmonary veins. This is also referred to as arteriovenous fistulae.

AVMs most commonly occur in the brain or spinal cords. Comparatively, brain AVMs are very rare and affect less than one percent of the population. AVM most commonly occurs in young adults, the deaths occurring in 10 to 15% of the patients.

Causes

Although the cause of AVM is not clear, some of the causes include:

  • Genetic pattern
  • Congenital (by birth)

Risk factors

  • Gender: AVM diseases are most common in males than in females
  • Family history: there may be inheritance of other medical conditions that predisposes the formation of AVM

Treatment

The main goal of the treatment is to prevent hemorrhage; the treatment would also focus on reducing the neurological complications such as seizures. Your doctor would determine the appropriate treatment based on your symptoms and diagnostic results.

Medications

Your doctor would prescribe medications to treat the symptoms such as headaches or seizures.

You must avoid activities that elevate your blood pressure and must avoid blood thinning agents such as warfarin.

Complications

Complications associated with AVM include:

  • Bleeding in the brain
  • Reduced oxygen supply to the brain tissue
  • Weakened blood vessels
  • Damage to the brain

Diagnosis

Your neurologist would review your symptoms and conduct a physical examination. Tests used for diagnosing AV malformations include:

  • Cerebral arteriography: this test reveals the location and characteristics of the arteries and veins, which is crucial in planning the treatment.
  • Computerized tomography (CT) scan: this test helps in giving a cross-sectional image of your brain.
  • Magnetic resonance imaging (MRI): This test helps in giving the detailed images of the brain

Brain tumor surgery is considered to be the gold standard treatment for the brain AVM. There are three types of surgical procedures:

Resection: if you have a rupture in the AVM, then conventional AVM brain surgery is opted for the removal of the AVM. Resection is performed when the AVM can be removed with little risk of hemorrhage or seizures. AVMs that are deep pose a higher risk of complications so; your doctor would recommend other treatment options.

  • Endovascular embolization : This procedure is less invasive than traditional type of surgery. The catheter is positioned in the arteries to the AVM, and an embolizing agent is injected to block the artery and reduce the flow into the AVM. This is a less invasive technique which is often performed before carrying out other surgical procedures to make the procedure safer by reducing the size of AVM or the bleeding.
  • Stereotactic radio surgery (SRS) : This procedure uses radiations to destroy the AVM. There is no incision required. The SRS beams are directed to damage the blood vessels and cause scarring. The scarred AVM blood vessels finally clot off one to three years of the treatment.

This treatment would be beneficial if the AVMs are small which are difficult for removing with a conventional surgery.

Do not get worried after being diagnosed with AVM, have little control over your health and improve quality of life just by following these simple steps:

  • Gain enough knowledge about your condition; it helps in decision-making, especially regarding your treatment options
  • Complications such as hemorrhage and stroke can cause emotional problems apart from physical problems. Cope with it and try hard to control your emotions.
  • Keep yourself close to family and friends, talk to them and get support during recovery
Which doctors are specialized in treating brain AVMs?
  • Vascular neurosurgeons: who are specialized in the removal of brain AVMs
  • Radiation therapists: who are specialized in the stereotactic radio surgery for treating the brain AVMs
  • Interventional neuroradiologists: who are specialized in the endovascular therapy of brain AVMs
  • Stroke neurologists: who are specialized in the medical management of brain AVMs

If you have an AVM in brain, it would not probably present any signs and symptoms until the AVM ruptures; the first sign includes hemorrhage.

If there is no hemorrhage the signs and symptoms would include:

  • Seizures
  • Headache
  • Muscle weakness or numbness in any part of the body

More serious signs and symptoms include:

  • Severe headache
  • Vision loss
  • Severe unsteadiness
  • Paralysis
  • Difficulty speaking
  • Confusion or inability to understand

These symptoms may begin at any age usually between ages 10 and 40. AVM can cause brain damage over time to time. After reaching middle age, brain AVM tend to remain stable and are less likely to cause any symptoms.

Pregnant women have worsened symptoms due to the alterations in blood volume and blood pressure.

Call your doctor immediately if you notice any signs and symptoms such as seizures, headaches or other symptoms. It is a medical emergency if the brain is bleeding.

Other Diseases

Arteriovenous fistula
Venous thromboembolism