Biodegradable Materials Available for Transarterial Embolization

Purpose: To review all available novel biodegradable occlusion technologies for vascular embolization and compare their properties and preclinical data to provide a reference for interventional radiologists interested in this field

Materials and Methods: Over the past decade, there has been increased interest in the development of biodegradable embolic agents for transarterial embolization (TAE) procedures. The goal of degradable embolic agents is to provide effective embolization on a transient basis. These embolic agents are removed from the body after achieving the intended clinical outcome without interfering with the function of other organs. Removing these agents will potentially minimize long-term sequelae of permanent embolic agents such as alternations in histologic architecture, vascular capacitance, and injury to tissue caused by “on-” or “off-” target deposition.

Results: An ideal biodegradable embolic should have tailored degradation timeframes, have a variety of tightly calibrated particle size distributions, easily be suspendable in physiological solutions, have easy delivery through traditional microcatheters, have full biological compatibility, and have multimodal imageability. The degradation of microspheres can occur because of enzymatic reactions or hydrolysis. When new biomaterials are developed, their preclinical safety and efficacy are evaluated in accordance with the Vascular and Neurovascular Embolization Devices guidance document published by the Food and Drug Administration. In development and currently available degradable occlusion agents are Gelatin (Gelfoam), Starch (Embocept), polylactic-co-glycolic acid (PLGA, Occlusin 500), cellulose–chitosan (Resosphere), hydroxyethyl acrylate (HEA, Biosphere Medical), polycarbonate, and poly-methyl acrylate (Occlugel). In this exhibit, we will discuss their basic chemistry, and mechanism of degradation. We will also discuss data on safety, efficacy, and performance as well as the advantages and disadvantages of each agent.

Conclusions: The materials available for embolization have evolved rapidly in the past few decades from autologous blood clots and muscle tissues to microspheres and gels made up of complex polymers that can be modified for a wide array of functions. The clinical application and development of new agents will continue to expand as the field of endovascular intervention grows.