Venous malformation

Venous malformation is most common vascular malformation among all congenital vascular malformation.  Venous malformation or venous predominant CVM was the most common type of CVM (53 %). Among the VM patients, the lower extremity was the most frequently affected site (42 %), followed by head and neck (26 %), upper extremity (16 %), trunk (9 %), and multiple site involvement (6 %).

 It remain asymptomatic for long duration . Symptoms depends on local infiltration & surrounding structure involvement. Symptomatic venous malformation has to be treated to reduced symptoms & local aggression of the lesion. For any line of treatment , first we have to consider that vascular malformation intima has mesodermal characteristics, if this inner lining is not destroyed completely then it will recur. (find out reference) . Surgical excision is useful only for localised and limited lesions. Aggressive excision can lead to significant loss of motor function, cosmetic problems, nerve damage, or massive bleeding in patients with extensive involvement(2). Glue & pv particles , block the lumen of vascular malformation. It leads to hypoxia to the endothelial cell. This hypoxia leads to neovascularization & recanalisation due to release of ………..factor from intimal cell. Absolute ethanol is a very effective sclerosant used for vascular malformation. The exact mechanism by which ethanol acts as an in vivo sclerosant is to denude the endothelial cell from the vascular wall and precipitate its protoplasm then cause fractures to the level of the internal elastic lamina. Platelet aggregation on the denuded surface then embolizes the vessel from the periphery to the center . Ethanol is believed to preferentially displace water molecules at the membrane surface, thereby penetrating the lipid bilayer and compromising the structural integrity of the cell membrane . This triggers necrosis and apoptosis of the treated tissue, inducing intravascular thrombosis and intense inflammatory response.(7) 

  For planning of treatment its very important to evaluate angiographic pattern of venous malformation. The three main venographic patterns—cavitary, spongiform, and dysmorphic—serve as the best lesion descriptors and can be translated into the interpretation of other imaging modalities.(5) These patterns is further subdivided into the following four types based on patterns of venous drainage 

 type I, isolated malformations without venous drainage; 

type II, malformations that drain into normal veins;

 type III, malformations that drain into dysplastic veins; and

 type IV, malformations consisting primarily of venous ectasia[5,6]

This figure represents different phlebography pattern of venous malformation.[5). 

Drawings show vascular malformation subtypes based on patterns of venous drainage. (Reprinted from Orthopedics Clinics of North America, Vol. 37, Legiehn GM, Heran MKS. Classification, diagnosis, and interventional radiologic management of vascular malformations, Pages 435–474, Copyright 2006, with permission from Elsevier)

A, Type I, consist of isolated malformations without venous drainage.

B, Type II, drain into normal veins.

C, Type III, drain into dysplastic veins.

D, Type IV, primarily consist of venous ectasia.

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