Combined Vascular Malformations
As the name suggests, combined vascular malformations involve more than one type of vascular channel (ie, capillary, venous, arterial, lymphatic). They are sometimes associated with syndromes and will bear the names of physicians credited with the original descriptions of the disorder. They are often associated with overgrowth of both soft tissues and bone. There are two notable syndromes in this category:
Klippel-Trenaunay Syndrome is a combined capillary lymphaticovenous malformation (CLVM). It is a slow-flow anomaly, often associated with limb overgrowth. Less frequently, there may be undergrowth of an affected limb. The capillary malformations are numerous, and a red/purple stain appears over a specific geographic territory of the body. Prominent veins result from abnormal veins with absent valves, and hypertrophy (overgrowth of the limb) can range from minor to extreme. Clots may form in the massively dilated venous channels, which can migrate to the lungs. Any part of the trunk or extremity may be affected. Diagnosis often requires an MRI.
Management is often conservative for these lesions. The decision to intervene with sclerotherapy or surgery is dictated by the presence of symptoms and limited only to areas that are problematic.
As with many vascular malformations, elastic compressive stockings are recommended for a limb with venous insufficiency and swelling. These stockings help reduce the pooling of fluid in the involved extremity. Surgery to correct leg length discrepancy is sometimes considered for large differences. Consultation with an orthopaedic surgeon is required for this procedure.
Parkes Weber Syndrome
Parkes Weber Syndrome is a combined capillary arteriovenous malformation (CAVM); it is a fast-flow vascular anomaly. It can affect any extremity, and may result in limb overgrowth. There is commonly a geographic pink, flat, warm stain on the skin and deeper arteriovenous connections which can penetrate muscle.
Shunting of blood can be extensive through these anomalous connections, sometimes resulting in high output congestive heart failure. This may require intervention, but management is usually similar to the conservative measures employed in Klippel-Trenaunay Syndrome.
Surgery and/or embolization/sclerotherapy must be considered carefully. These interventions may trigger expansion of the AVM component of the lesion, as previously described.