Vascular Malformation
While the arteries (arteries) in our body carry blood to the peripheral organs, the veins and the lymphatic system return the blood to the heart. Abnormal connections between these vessels or congenital clusters of veins and lymphatic vessels are generally referred to as vascular malformations. These are classified as high-flow and low-flow.
High-Flow Vascular Malformation Arteriovenous Malformation (AVM)
It is a vascular tangle formed by the abnormal connection between arteries and veins. Normally, the blood should travel through the arteries to the peripheral tissues, but due to these abnormal connections, it returns to the heart prematurely, which may lead to impaired perfusion of the distal organs, bleeding, pain, swelling, and organ dysfunction. Since AVMs have a very high flow rate, pulsation or vibration can be felt in superficially located ones. The area where the AVM is present is warm due to the increased blood flow.
Arteriovenous Malformation Symptoms:
The symptoms vary depending on the location of the lesion, its size, and whether bleeding is present, and therefore can manifest in many different ways. Sometimes, it causes pain that significantly reduces the quality of life.
In such vascular malformations, bleeding is one of the most serious complications. If the malformation is located in the brain, it can cause intracranial hemorrhage, which may result in death. Swelling, organ dysfunction, and deformities may occur; in addition, pressure on surrounding organs or nerves can lead to a wide range of symptoms.
Arteriovenous Malformation Treatment
Today, the treatment of arteriovenous malformation is embolization performed through angiography. The goal of angiographic treatment is to completely close off the abnormal vascular tissue between the artery and the vein, a procedure known as embolization. In some cases, this can be achieved with a single angiographic session, while in others, multiple sessions may be required.
Risks of AVM Embolization Treatment
There are two types of risks in angiographic treatment.
The first includes risks that may occur in any angiographic procedure, which are specific to the angiography itself.
The second involves risks associated with the embolization process. The most significant risk is the unintended blockage of normal vessels. Your doctor will explain these risks to you in detail. All AVMs located outside the brain can be completely treated with angiographic procedures.
Low-Flow Vascular Malformations
Venous Malformation: This is a congenital cluster of abnormal veins. In superficial cases, it is usually noticed in infancy due to discoloration and swelling. Deeply located ones may show no signs and are often detected later in life, around the ages of 20–30. These abnormal vessels grow in proportion to the child’s overall growth. Spontaneous regression is not possible. Because these are slow-flow lesions, clotting may occur, leading to pain and firmness. When they involve joint regions, they can interfere with normal growth.
How Is Venous Malformation Diagnosed?
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If the lesion is visible on the skin, diagnosis can be made based on its appearance alone.
Color Doppler ultrasonography is the first and primary diagnostic method. If Doppler ultrasound is insufficient or if it is necessary to assess the relationship of the vessels with joints and plan treatment, an MRI may be required.
How Is Venous Malformation Treated?
Unfortunately, this condition cannot be treated with medication. If it is very mild, treatment may not be necessary. However, in most cases, treatment is required due to pain and cosmetic concerns. Supportive treatments such as compression bandages and pain relief medications may be used.
Needle-based treatment (ablation or sclerotherapy) is an effective method that can be used in nearly all venous malformations. Sclerotherapy usually requires multiple sessions. Another treatment option is surgery. In some cases, a combination of both (sclerotherapy and surgery) may be necessary.
The choice of treatment depends on the type of malformation, the symptoms it causes, the patient’s age, and other factors. Surgery is highly effective if the entire malformation can be removed. However, if it cannot be completely excised, it may recur and grow over time.
Sclerotherapy is a simpler treatment method. It is performed under ultrasound guidance in an angiography suite. The procedure involves inserting a needle to visualize the venous connections, followed by the injection of a special medication. The goal is to destroy the abnormal vessels while preserving the normal ones, thereby relieving pain and improving appearance.
Although it is performed in an angiography room, this is not a full angiographic procedure—it is simpler. Depending on the density of the vascular structures, the procedure lasts about 15 to 30 minutes. Patients can usually go home immediately after the procedure, with no need for hospitalization.
To ensure comfort and eliminate pain or anxiety during the procedure, pain relievers and sedatives are administered intravenously. The procedure is therefore very comfortable and painless.
In the days following treatment, some patients may experience pain and firmness in the treated vessels, which typically lasts a few days, though some may not feel any discomfort at all. It may take two to three months to observe the full healing effect. It is generally not possible to completely eliminate the malformation in a single session; multiple treatment sessions may be necessary. The number of sessions required depends on the size and density of the vascular structures.
In cases of recurrence, sclerotherapy can be safely repeated.
Lymphatic Malformation
It belongs to the group of low-flow vascular malformations and is an anomaly of the lymphatic vessels. The lymphatic flow in the affected area is impaired.
How Is Lymphatic Malformation Diagnosed?
Lymphatic malformations usually present as swelling, most commonly in the neck region. The lesions are painless, non-compressible, and the skin over them remains intact without discoloration, temperature change, or palpable pulse.
Although Doppler ultrasonography is generally sufficient for diagnosis, magnetic resonance imaging (MRI) is the primary diagnostic method for determining the extent of the lesion, its relationship with surrounding soft tissues, and for treatment planning.
How Is Lymphatic Malformation Treated?
Interventional radiology treatments for lymphatic malformations vary depending on whether the malformation is microcystic or macrocystic.
In macrocystic lymphatic malformations, sclerotherapy is the first-line treatment.
How Is Sclerotherapy Performed?
In macrocystic lymphatic malformations, once the cyst is identified using ultrasonography, a thick needle is inserted into the cyst, and its contents are aspirated. Then, under fluoroscopic guidance, a contrast agent is injected to assess the cyst’s connection with surrounding vessels. Once it is confirmed to be safe, a sclerosing agent is injected into the cyst.
Depending on the size of the lesion and the amount of medication used during the procedure, sclerotherapy may be performed in a single session or over several sessions.
In microcystic lymphatic malformations, ablation therapy is preferred as the first-line treatment. Radiofrequency, laser, microwave, or cryoablation techniques can be applied.
Lymphatic malformations can also be treated surgically, in addition to interventional methods.