Control of experimental traumatic hepatic hemorrhage by transcatheter embolization

Advances in Biomaterials and Technologies for Vascular Embolization

Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape-memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.

Transcatheter embolization using degradable crosslinked hydrogels

Therapeutic embolization is the selective transcatheter blockage of blood vessels or diseased vascular structures. The majority of current embolization materials in clinical use are permanent. There are clinical situations however, in which temporary embolization is desired. Degradable hydroxyethyl acrylate (HEA) microspheres have been synthesized. Canine renal arteries and rabbit central auricular arteries were embolized with HEA microspheres, and compared with degradable human serum albumin (HSA) microspheres, and permanent microspheres. HSA and HEA microspheres both achieved temporary occlusions. HSA and HEA microspheres were recanalizated at 1 and 3 weeks, respectively, while arteries occluded with permanent microspheres did not recanalize. All embolic microspheres led to tissue infarction, with the short-term HSA microspheres providing the least damage, and the permanent microspheres leading to extensive damage. Advantages of temporary embolization were not convincingly demonstrated since temporary occlusions still led to tissue infarction.