vm VS. avm
Vms do not have arterial involvement. If visible, they display blue on the skin, like a regular vein but more visible and complex. AVMs are high flow with arterial involvement. If visible, they display as a network of red vessels. AVMs also have "shunting." An artery sends blood at high pressure without intervening capillaries straight into a vein or veins; the artery becomes enlarged, and the veins become distended. If an AVM bleeds, the bleed is more serious than if a VM bleeds. VMs also respond to some types of treatment that work less well for AVMs, such as bleomycin injection or radiofrequency ablation.
Sclerotherapy uses some type of caustic agent to destroy the endothelial cells in AVM or VM vessels, such as alcohol. Embolization is similar but simply means closing off the malformation with a substance like Onyx or glue. It does not destroy anything; it's like putting a dam across a river. Sclerotherapy would be like poisoning the river and drying it up. Does that help?