The second category of vascular anomalies is the vascular malformation. These growths are detectable at birth and have reached most of their growth in relation to the size of the patient at birth. In other words, their growth is commensurate with the growth of the child. The sub-classification of these lesions is dependent on the type of blood vessel involved and the amount of blood flow. For example, a venous malformation consists of veins; a venule malformation is called a portwine malformation, and a growth with arteries and veins is an arterial-venous malformation (AVM).
Treatment for venous malformation: The management of these lesions often requires several modalities. The first modality often used is intralesional injection to promote collapse of the lesion. This method requires sedation of the child while a solution is injected into the vessels of the growth. If this is successful, subsequent surgical excision can be safely performed.
Treatment for arterial-venous malformation: These lesions have a higher blood flow making surgical extirpation more difficult. This requires a procedure usually performed by an interventional radiologist to place a small tube thru the larger blood vessel in the groin to the blood vessel feeding the mass. Small particles are then injected to promote collapse of the mass. Once this is done, surgical removal can be performed.
Treatment for portwine malformation: These lesions may be seen as a midline pink area of the skin at birth. They often regress, but occasionally require treatment. The lesion may also be seen in other areas of the body and is a result of a deficiency in the nerves that regulate blood flow to that area of the skin. Early treatment with lasers may prevent more difficult treatment in the future. Maintenance treatment is often required. If the malformation is located in a certain distribution of the face involving the 5th cranial nerve, an evaluation for Sturge-Weber syndrome should be done.
The third category for vascular malformations involves the lymphatic system called a lymphatic malformation. This lesion is a sponge-like collection of abnormal channels and spaces that contain clear fluid. The incidence in babies is unknown; however, they are not uncommon. Other terms for LMs are cystic hygroma and lymphangioma.
Lymphatic channels sprout from veins in early embryonic life. Protein-rich fluid normally filters out of blood-filled capillaries into tissues throughout the body. The lymphatic system serves to transport this fluid back into the venous system. In the gastrointestinal tract, lymph is thicker, containing absorbed fat. This fluid is called chyle.
Although the precise cause is unknown, LMs are believed to be caused by an error in the formation of these tiny, thin-walled sacs and tubes in the embryonic period. No known food, medication, or activity during pregnancy can cause an LM.
When do LMs occur?
LMs arise during the formation of the primitive lymphatic system from the venous system before five to six weeks of embryonic life.