Vascular conditions
Vascular malformations
Vascular malformations are abnormal collections or connections of blood vessels or lymphatic channels. They are present from birth, although many do not cause problems until later in life. Depending on their type, size and location, they may cause pain, swelling, bleeding or difficulty using the affected area.
Dr Ryan McConnell assesses and treats adults with vascular malformations of the body and limbs in Sydney, using image-guided techniques such as sclerotherapy and embolisation.
Understanding the condition
What is a vascular malformation?
A vascular malformation is a developmental abnormality in the formation of blood vessels or lymphatic channels. Unlike some birthmarks, such as infantile haemangiomas, vascular malformations do not shrink with time. They usually grow in proportion with the body and may enlarge or become symptomatic during hormonal changes such as puberty and pregnancy, or after injury or infection.
Vascular malformations are not cancerous. Research has shown that many are linked to genetic changes in the cells lining the vessels, and this understanding is leading to new targeted medicines for some types.
Classification
Types of vascular malformation
Vascular malformations are grouped by the type of vessel involved and by how quickly blood flows through them.
Low-flow malformations
Low-flow malformations make up the large majority of vascular malformations. They include:
- Venous malformations — the most common type treated by interventional radiologists. They often appear as a soft, compressible swelling, sometimes with a bluish tinge, that may become larger when the area is lowered or during exertion. Episodes of pain and tenderness can occur when small clots form within the malformation.
- Lymphatic malformations — collections of abnormal lymphatic channels or fluid-filled cysts. They are described as macrocystic (larger cysts), microcystic (very small channels) or mixed. They can become swollen with infection or bleeding into the cysts.
- Capillary malformations — such as port-wine stains, which involve the small vessels of the skin. These are usually managed by dermatologists, often with laser treatment.
High-flow malformations
Arteriovenous malformations (AVMs) are abnormal connections between arteries and veins that bypass the normal small vessels. The central tangle of abnormal vessels where these connections occur is called the nidus. Because blood flows through them quickly, AVMs can feel warm, pulsate or produce a "buzzing" sensation, and may cause bleeding, pain, skin changes or ulceration. AVMs are less common than low-flow malformations and are often more complex to treat.
Dr McConnell treats malformations of the body and limbs. AVMs of the brain and spinal cord are managed by neurosurgical and neurointerventional teams.
Symptoms
Symptoms of vascular malformations
Symptoms vary widely. Some malformations cause no problems, while others can affect daily life.
Symptoms may include:
- a visible lump, swelling or discolouration of the skin
- pain or aching, which may be worse with activity, standing or at certain times of the month
- episodes of painful swelling caused by clotting within the malformation
- bleeding, skin breakdown or ulceration
- reduced movement or function of a limb or joint
- swelling, leakage of fluid or recurrent infection, particularly with lymphatic malformations
Assessment
How are vascular malformations diagnosed?
Assessment usually involves a review of your symptoms and examination, together with imaging such as:
- ultrasound with Doppler, to assess the vessels and how quickly blood flows through them
- MRI, to show the full extent of the malformation and its relationship to surrounding muscles, nerves and organs
- CT angiography or catheter angiography, which may be used for high-flow malformations or when treatment is being planned
Correct classification is important because the type of malformation determines the treatment options.
Treatment
Treatment options for vascular malformations
Not every vascular malformation needs treatment. The decision depends on your symptoms, the type and location of the malformation, and the potential benefits and risks of treatment. Management may include:
- observation and supportive measures, such as compression garments and pain relief
- image-guided procedures, such as sclerotherapy or embolisation
- targeted medication for selected complex malformations, usually coordinated through a specialist team
- surgery for selected malformations, sometimes combined with image-guided treatment
Complex malformations are often managed by a team that may include interventional radiologists, vascular, plastic or general surgeons, dermatologists and other specialists.
Low-flow malformations
Sclerotherapy for venous and lymphatic malformations
Sclerotherapy is the main image-guided treatment for low-flow malformations. Using ultrasound and X-ray guidance, a fine needle is placed directly into the malformation and a medication (sclerosant) is injected. The sclerosant irritates the lining of the abnormal channels, causing them to scar and shrink over time. The choice of sclerosant depends on the type of malformation and its appearance on imaging.
Suggested image
Ultrasound image during sclerotherapy, showing the needle placed within a venous malformation.
High-flow malformations
Embolisation for arteriovenous malformations
Embolisation is used to treat high-flow malformations. The nidus may be reached through a catheter in an artery or vein, or by direct needle puncture. An embolic agent is then delivered to block the abnormal connections.
Vascular malformations often require more than one treatment session to control symptoms. Whether you need to stay in hospital overnight depends on the type of treatment and your individual circumstances.
An arteriovenous malformation: a feeding artery (red) connects directly to a tangle of abnormal vessels (the nidus), which drains into a vein (blue). Right: a catheter in the feeding artery delivers embolic material to block the nidus.
Risks & considerations
Risks of sclerotherapy and embolisation
Swelling, bruising and discomfort in the treated area are common for several days after treatment. Other potential risks depend on the location of the malformation and the agent used.
Your individual risks will be discussed with you before any procedure.
Potential risks include:
- skin blistering, discolouration or ulceration
- injury to nearby nerves or other structures
- non-target embolisation, where the agent affects normal vessels or tissue
- infection or bleeding
- complications at the puncture or catheter access site
- reaction to the medications or contrast used
- recurrence or regrowth of the malformation
FAQs
Frequently asked questions about vascular malformations
What causes vascular malformations?
Is a vascular malformation dangerous?
What is the difference between a venous malformation and an AVM?
Can vascular malformations be cured?
What is the life expectancy with a venous malformation?
Do I need a referral?
Vascular malformations
Discuss a vascular malformation with Dr Ryan McConnell
If you have been diagnosed with, or are being investigated for, a vascular malformation, Dr McConnell can review your imaging and history to help determine whether an image-guided treatment may be appropriate.