Introduction

Definition of vascular malformations

Vascular malfunctions are malformations in the blood vessels. They are quite rare, affecting around 1% of births all around the world with the most common form affecting 1 in every 5,000 to 10,000 births. Commonly found in children at birth, this condition can develop in various parts of the body. It tends to go away later in life during childhood or adulthood.¹

Types of vascular malformations

Subtypes and variations  

• Capillary Malformations - small parts of the enlarged capillaries that are formed in the brain. Most of the time it does not cause additional problems but sometimes, there is a chance of causing a haemorrhage
• Venous Malformations - The most common type of vascular malformation and it is formed in the vein. These veins transport blood back to the heart to carry oxygen
• Lymphatic Malformations - These lymphatic channels produce a fluid-containing cyst and they form in the soft tissues of the face, armpit and neck areas
• Arteriovenous Malformations - This is when the arteries and veins tangle incorrectly, so instead of connecting to the capillaries, these arteries transport blood to the veins through the tangle. It can have an effect on the brain and spine
• Cavernous Malformations - These are when the capillaries are tightly packed in the brain, called caverns, causing the blood flow to slow down^1,2

What are the causes of vascular malformations?

In most cases of vascular malformation, it is commonly caused by a localised development that is abnormal in the vascular channels, formed in utero. These are typically found at birth. 

In less common cases, an injury can also be the cause, where there is damage to the blood vessels and over time form into a vascular malformation. Though the cause of vascular malformation is yet to be fully understood, some malformations are caused by a genetic mutation (change) present in the local tissues only or less commonly when it is inherited. For example, arteriovenous malformation in the lungs is caused by a mutation in the HHT gene.^1,2 

Symptoms of vascular malformations and risk factors

Location-specific symptoms  

• Cutaneous symptoms - affecting the hair, nails, sweat and oil glands
• Musculoskeletal symptoms - fatigue, stiffness, problems in movement, pain, bending a joint
• Neurological symptoms - weakness, difficulty in walking and swallowing food, tremors
• Gastrointestinal symptoms - bleeding, anaemia, lymph fluid leak 
• Cosmetic disfigurement
• Haemorrhage
• Thrombosis
• Strokes
• Aneurysms^1,3

Risk factors  

Some risk factors include:^1,3,4

• Blue rubber bleb venus syndrome - venous malformation in the digestive system and the intestines, causing you to have dark blue, red or black coloured bumps on the skin
• Hereditary haemorrhagic telangiectasia - tangles of the capillaries 
• CLOVES - causes arteriovenous malformations in the spine. Can also cause scoliosis
• Parkes-Weber syndrome - causes arteriovenous malformations in your arms and legs
• Klippel-Trenaunay syndrome - causes venous and lymphatic malformations

How are vascular malformations diagnosed?  

Clinical evaluation

Vascular malformation does not always show symptoms, so your doctor may only discover the condition after conducting the tests, to check for a different issue.^1,5

Imaging studies

Your doctor will use imaging tests, especially to look at the blood flow and to check for vascular malformations. These tests include:^1,5

• Ultrasonography
• Magnetic Resonance Angiogram
• Computed Tomography Angiogram
• X-rays

What are the treatment options?  

Depending on the severity of the condition, the treatment will be different too.

Conservative management

Treatments for vascular malformation normally minimise the symptoms and reduce potential complications. Malformations that do not cause complications or additional problems, may not require treatment and will need to be observed over time and to reduce inflammation with the help of compression garments.⁶

Interventional procedures

Vascular malformations that affect the blood vessels, treatments may involve closing off and or surgically removing the blood vessels that are affected. The treatments used for these conditions are often minimally invasive techniques, including:^5,6

• Sclerotherapy
• Laser therapy
• Radiosurgery
• Catheter embolisation

Prognosis and outcomes  

Vascular malformation, which may look like a birthmark, can affect the appearance and self-confidence of an individual, which can lead to depression and anxiety. However, most malformations can be treated easily and do respond well to the treatments.

The more serious vascular malformations, such as arteriovenous malformations in the brain can cause serious complications that can be life-threatening when not treated properly.^1,6

Summary

Vascular malformation is a condition that affects the blood vessels and it is mainly found at birth as a birthmark. Many factors can worsen the blood vessels causing its changes, such as accidents, and hormonal changes. Your local GP and the healthcare team can treat vascular malformations that resemble a birthmark, though there is a chance these can come back. In more severe cases arteriovenous malformations in the brain or the spine can cause bleeding, becoming dangerous. It is important to talk with your local GP if you notice any abnormalities or changes in your symptoms, as it is important to treat the disorder timely and properly.