Definition and Overview
Vascular malformation is a broad term used to refer to abnormalities that affect the vascular system including lymph vessels, arteries, and veins.
The malformation is congenital and therefore begins at the time the child is born. However, it usually doesn’t manifest prominently until the baby has entered into childhood. It develops as the person ages, so it progresses slowly, though there are times when the growth is quite fast.
There are different types of malformations. These include:
Port-wine stain or capillary malformations – As the name suggests, the abnormality is detected in the capillaries, which are the smallest blood vessels in the body. They are as thin as a strand of hair but are branching out. They are present in all tissues in the body. Like a stain, they can appear as a discoloration on the surface of the skin. Their size can range from small-scattered islands to big ones covering a large area. They are normally found in the neck and face. These malformations are often confused with capillary lesions that are noticeable in neonates. The major difference is that the latter can disappear by the time the child reaches a year old. Thus, almost always it doesn’t need any treatment.
Lymphatic malformations – These are abnormalities found in the lymph vessels, which are valve structures that deliver excess fluid from the body’s tissues into the circulatory system (or the bloodstream). When they are malformed, they can cause fluid buildup, causing the dilation or the swelling of the vessels. In turn, lumps in the lymph areas become more visible.
Venous Malformations – These are malformations that affect the veins, which are blood vessels responsible for carrying blood back to the heart, where it receives oxygen that will be distributed to cells and tissues. It is the most common among the types and appears in many different forms, from superficial lesions to a lumpy mass.
Arteriovenous Malformation – This malformation can occur in the network that connects the veins and arteries, which are responsible for delivering blood from the heart to different areas of the body.
Causes of Condition
The causes of vascular malformation are yet to be established. The main belief is that it has something to do with the genes as the malformation can occur as these vessels develop during conception.
However, there are risk factors depending on the specific condition the child is diagnosed with. For instance, children who may have Sturge-Weber syndrome may be at risk of having capillary malformations. Although the syndrome is congenital, it is not familial (or passed on). Aside from a birthmark (port-wine stain), the child may also have neurological issues.
Another condition that is often associated with vascular malformation is HHT or hereditary hemorrhagic telangiectasia. As it name implies, this can lead to bleeding. HHT is caused by any of the three genes called SMAD4, ACVRL1, and ENG. When these genes mutate, they can cause arteriovenous malformations, in which the blood flows from the arteries directly into the veins. The high pressure of blood can strain the vessels and irritate the tissues, which may then result in bleeding.
A child with Parkes-Weber syndrome, meanwhile, may develop lymphatic and capillary malformations. The person may develop a bigger limb, especially the leg, which happens because the bones and tissues in the area seem to overgrow. Aside from port-wine stains, they may also have small fistulas in between the veins and arteries that can disrupt the flow of blood. This condition can be caused by a mutated gene known as RASA1, but usually it is sporadic, which means it occurs without any verifiable cause.
- Presence of lumps or mass under the skin
- Appearance of a knotted part of the skin, which may be caused by dilated large blood vessels
- Lesions that look like birthmarks
- Red, maroon, or bluish discoloration on the surface of the skin (the color may indicate the depth of malformation)
- Swelling of a limb
- Heart problems
Because there are many different types of malformations that can occur in various areas of the body, the specific symptoms can also be varied. For instance, if it occurs in a blood vessel of the brain, it may result in neurological problems such as disorientation, blurry visions, or a headache. When it is near or within the heart, a symptom can be a heart attack or organ failure. A person may also develop glaucoma if the malformation is in the eyelids.
Often the symptoms will start to appear as the child grows older. They are also usually slow in development, but they can speed up in certain cases, such as when the person has been injured (e.g., an accident) or develops a hormonal imbalance. Certain medications may also alter the development of these malformations.
Who to See and Types of Treatment Available
Since the malformations may appear as early as childhood, pediatricians are trained to assess, diagnose, treat, and manage these conditions. However, they work alongside other specialists such as surgeons or radiologists to perform certain tests and treatments.
Imaging exams such as CT scans and ultrasound can be used to detect vascular abnormalities, their severity, shape, size, and other specific details to their profile. The data will be one of the bases for creating the treatment programme.
There’s no one-size-fits-all approach to treatment, and more often than not, an invasive surgery isn’t always the answer, although it may be helpful to remove any lump that may be growing in soft tissues or bones. It is also necessary if the bleeding is happening internally. Nevertheless, it may not completely remove the problematic vessel, or the condition may simply reappear later. One of the techniques used is embolization, in which the malformed arterial feeder is cut off without harming the regular artery by using a small pencil-thin tube that is then filled with glue or beads to shut it off. The procedure is non-invasive, so it doesn’t require general anesthesia.
Other options are:
- Laser therapy
- Removal of localized overgrowth
- Ablation using radiofrequency
Compression garments or stockings
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Laakso A, Dashti R, Juvela S, Niemelä M, Hernesniemi J. Natural history of arteriovenous malformations: presentation, risk of hemorrhage and mortality. Acta Neurochir Suppl. 2010;107:65-69. PMID 19953373. www.ncbi.nlm.nih.gov/pubmed/19953373
Spagnuolo E. Surgical management of cerebral arteriovenous malformations. In: Quinones-Hinojosa A, ed. Schmidek and Sweet Operative Neurosurgical Techniques. 6th ed. Phildelphia, PA: Elsevier Saunders; 2012:chap 83.