Embolization is the interventional radiological procedure in which abnormal vessels are closed off with various substances (e.g., alcohol, glue, coil). This technique is the main treatment for most fast-flow vascular anomalies (AVMs, AVFs, Hemangiomas).
Embolization can also be used to treat large venous channels of slow-flow vascular anomalies. Depending on the nature of the abnormality, various embolic agents can be used. Alcohol and glue (NBCA) are permanent embolic agents and both are commonly used to treat AVMs. Coils (metal wires) are also permanent embolic materials and are commonly used for AVFs (coils are available in a variety of sizes and configurations). Particles such as PVA (polyvinyl alcohol) and acrylic gelatin microspheres can also be used for AVMs depending on the nature of the anomaly. Another rarely used embolic agent is the detachable balloon that can be used to treat AVFs. Gelfoam is another agent, however it is not a permanent embolic agent and is generally used to temporarily occlude the abnormal vessels (e.g., bleeding or presurgical devascularization).
Treatment of vascular anomalies with embolization requires extremely careful technique in addition to selection of the appropriate embolic agent for the best therapeutic outcome and to minimize complications. Most patients require more than one procedure. No matter how careful the procedure is performed, complications such as tissue necrosis may be unavoidable in some cases. Patients should discuss the expected benefits and potential complications of the embolization procedure, as well as alternative treatment options in detail with the interventional radiologist before the procedure.