What are vascular malformations? Types, diagnosis, and care explained

Vascular malformations are a group of conditions that can affect veins, arteries, capillaries, and lymphatic vessels. They are best understood as types of birthmarks.

Dr Ian McCafferty, a consultant diagnostic and interventional radiologist, provides an expert insight into the types, signs, and the latest approaches in the diagnosis and treatment of vascular malformations.

What are vascular malformations?

Vascular malformations are structural abnormalities in the body’s blood and lymphatic vessels that result from abnormal development of the vascular system during pregnancy. 

There are several types; broadly speaking we split them into low flow (fluid moving slowly) and high flow malformations (fluid moving fast). They include the following:

Low flow vascular malformations:

• Low flow Venous malformations (LFVM): these are abnormal veins that can appear as blueish, soft swellings. Most have large blood spaces but others can be quite solid.
• Low flow Lymphatic malformations (LRLM): abnormal lymphatic channels that often present as either macrocystic or microcystic fluid-filled masses and can lead to fluid accumulation and swelling
• Capillary malformations: also known as port-wine stains, these are flat, red, or purple discolorations of the skin caused by dilated capillaries. 

High Flow vascular malformations:

• Arteriovenous malformations (AVMS): these are birthmarks where arteries are directly connected to veins without the usual capillary network. They are fast flowing and often increase in size and cause bleeding.

Vascular malformations are benign non-cancerous lesions which don’t spread to other parts of the body. However, they can cause local complications, including pain, swelling, bleeding, infection, and impaired organ function due to growth. 

How are vascular malformations diagnosed?

A thorough medical history and physical examination by a specialist are the first steps. The healthcare professional will check for visible or palpable malformations, and ask about any pain, swelling or bleeding. 

Imaging studies are then performed to confirm the type and extent of the malformation:

• Ultrasound with Doppler imaging: a test that uses sound waves to create images of blood flow and vessel structure. 
• MRI: a scan that uses radio waves to generate detailed images of the body’s internal structures, including the organs, bones, muscles, and blood vessels. 
• CT scan: a scan that uses X-rays to produce cross-sectional images of bones, blood vessels, and soft tissues.
• Angiography: a specialised procedure that involves injecting contrast dye into the blood vessels to visualise their structure and flow patterns. 

Accurate diagnosis not only identifies the type of vascular malformation but also helps in determining the most appropriate treatment strategy.

What are the treatment options for vascular malformations?

The approach to treating vascular malformations is determined by their type, size, location, and associated symptoms.

While some malformations may not require immediate treatment, others may need intervention to prevent complications or improve quality of life. Common treatment approaches include:

Observation

Observation may be recommended for small, asymptomatic malformations to track any changes over time without immediate intervention.

Medications

Certain drugs, such as sirolimus, may be prescribed to manage symptoms or slow the growth of specific types of vascular malformations, particularly lymphatic ones. 

Sclerotherapy

Sclerotherapy is a minimally invasive procedure that involves injecting a special solution directly into the malformation to shrink the abnormal vessels. It’s often used for treating venous or lymphatic malformations.

Bleomycin Electrosclerotherapy (BEST)

BEST is a new treatment that is showing fantastic early results. Previously bleomycin sclerotherapy had been a second line treatment which worked well but required numerous treatment sessions to achieve benefit. BEST which involves the use of an electrical current passed through the tissues after bleomycin had been administered has been shown to increase the uptake of the drug within the cells by 700%. This allows for less treatment sessions and a reduction of bleomycin dose with less side effects.

Laser therapy

Laser therapy is a minimally invasive procedure that directly targets the malformation with focused light energy. Specific wavelengths of light are then absorbed by the haemoglobin, generating heat that destroys the abnormal vessel. 

Embolisation

Embolisation is a minimally invasive procedure that involves inserting a catheter into the affected blood vessels and delivering substances to seal them off. It’s often used for arteriovenous malformations. 

Surgery

Surgical removal may be performed in cases where the malformation causes functional impairment or cosmetic concerns. Surgery can be complex, especially for extensive or deep malformations, and is often combined with other treatments for optimal results.

Can vascular malformations grow or change over time?

Yes, vascular malformations may grow or change over time. They usually grow proportionally with the individual, but they can also grow in some cases due to hormonal changes, trauma, or infection. In addition, life stages such as puberty, pregnancy, or the menopause can exacerbate the condition.

Regular follow-up with a specialist is essential to monitor these changes and adjust the treatment plan accordingly. Early intervention can prevent the progression of symptoms and improve outcomes.

If you are concerned about a possible vascular malformation, consult with Dr McCafferty via his Top Doctors profile.