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.