Arteriovenous Malformation (AVM)

At a Glance

Arteriovenous Malformation (AVM) is a vascular structure where arteries and veins are abnormally connected and intertwined without passing through capillaries.

Lesions can occur in various parts of the body and are relatively common in the brain and spinal cord, with symptoms varying depending on the location of the lesion and the vascular condition.

How the Disease Works

The exact cause is generally unknown, and while most are present congenitally, they can also be discovered after birth or at a later stage.

Rapid blood flow that bypasses capillaries can reduce oxygen supply to surrounding tissues and place strain on blood vessels, which can lead to risks of tissue damage or vascular rupture.

Patterns Vary by Person

The risk of symptoms and complications may vary from person to person depending on the location and size of the lesion, risk of bleeding, presence of symptoms, and overall health status.

Broad framework of diagnosis and management

There may be almost no symptoms, but headache, seizures, pain, vision problems, muscle weakness, difficulty with movement or speech, dizziness, confusion, or loss of consciousness may occur, and if a blood vessel ruptures, bleeding and brain damage can occur.

During the diagnostic process, symptoms and medical history are reviewed and a physical examination is performed, and imaging tests such as CT, MRI, ultrasound, or angiography may be conducted as necessary.

Current stage of treatment

The mere fact that a vascular malformation is visible on imaging cannot be used to determine an individual's risk of bleeding or the need for treatment; the anatomical characteristics of the lesion and the symptoms must be interpreted together.

Management is determined by combining observation, identification of warning signs, symptom control, intervention, or assessment of surgical possibility, tailored to the characteristics of the lesion and the individual's health status.

Treatment selection is determined by comprehensively considering the location and size of the lesion, symptoms, overall health status, and bleeding risk; surgery for brain or spinal cord lesions requires a careful comparison of expected benefits and risks.

How to read clinical trials

Observational studies related to arteriovenous malformations are registered in clinical trial registries, but study registration alone cannot determine treatment efficacy, safety, or whether the intervention constitutes standard of care.

Points to verify in clinical encounters

In clinical practice, it is important to verify the location and size of the lesion, history of prior bleeding or seizures, required imaging studies, expected benefits and risks of observation versus intervention, and the local emergency medical system or healthcare providers available for immediate use in case of emergency symptoms.