Embolization Agents—Which One Should Be Used When? Part 1: Large-Vessel Embolization

The first clinical transcatheter embolization procedure was reported in 1972, utilizing autologous clot as the embolic agent. Since then, embolization procedures have become progressively more sophisticated and the number, variety, and complexity of embolic agents has exponentially increased. Hence, one of the most difficult decisions an operator must make before any given embolization procedure is what embolic agent to use.

A systematic approach can be used to determine the best agent for most clinical scenarios encountered. The first decision that must be made by the operator is whether or not a vessel can safely be sacrificed without putting the downstream organ(s) at significant risk. Once it is decided that the vessel can be sacrificed, to determine the best embolic agent to use, the operator should answer three questions:

Is the vessel to be embolized large or small? How long is the vessel to be occluded? Is the tissue supplied by the vessel to remain viable after the embolization?

After these three questions are answered, the decision regarding which embolic agent to use is simplified.

The purpose of this article is threefold: to provide a brief historical perspective on embolization procedures, to describe a systematic algorithm applicable to most clinical situations requiring embolization, and to give a brief description of the commonly used embolic agents.

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