title: Histomorphology of thrombus organization, neointima formation, and foreign body response in retrieved human aneurysms treated with hydrocoil devices.
abstract: Biological processes, such as thrombus organization, endothelialization, and foreign body response, that occur following embolization of intracranial aneurysms are poorly understood. We examined 13 human aneurysms (retrieved at autopsy 1-74 days postembolization) treated with hybrid hydrogel-platinum coil devices and platinum coils. The specimens were embedded in methyl methacrylate and ground sections were surface stained. Using light microscopy, thrombus organization in the sac, endothelialization of the neck, and foreign body response to the embolic devices were determined. The area percentages of the sac occupied by embolic devices and unorganized thrombus were quantified using image analysis. Thrombus organization increased over time, but was incomplete up to 74 days post-treatment. Neointima formation had started at 5 days upon dense fibrin depositions and progressed to form a new vessel wall at 74 days. The foreign body response to the hydrogel was characterized by mononuclear macrophages, while platinum coils were surrounded by multinuclear foreign body giant cells. Histometric aneurysm occlusion ranged from 89 to 100% and embolic devices occupied 31-64% of the aneurysm sac. These findings showed that the hydrogel-based devices occupied a large percentage of the aneurysm sac, provided a framework for thrombus organization to occur, and elicited less severe foreign body response than platinum coils.
authors.affiliation: Department of Neurology, Neuroscience Institute, Paracelsus Medical University, Christian Doppler Clinic, Ignaz Harrer Strasse 79, Salzburg A-5020, Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Killer
authors.affiliation: Department of Neurosurgery, Semmes-Murphey Neurologic and Spine Clinic, University of Tennessee, 6325 Humphreys Blvd, Memphis, Tennessee 38120.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Arthur
authors.affiliation: Mid South Imaging and Therapeutics, 6019 Walnut Grove Road, Memphis, Tennessee 38120.
authors.forename: John D
authors.initials: JD
authors.lastname: Barr
authors.affiliation: Department of Neurosurgery, Paracelsus Medical University, Christian Doppler Clinic, Ignaz Harrer Strasse 79, Salzburg A-5020, Austria.
authors.forename: Bernd
authors.initials: B
authors.lastname: Richling
authors.affiliation: MicroVention Terumo, 1311 Valencia, Tustin, California 92780.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Cruise
mesh_terms: D000783:Aneurysm / Q000628:therapy*; D001344:Autopsy; D003952:Diagnostic Imaging; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D005547:Foreign Bodies; D005549:Foreign-Body Reaction; D006801:Humans; D020100:Hydrogels / Q000009:adverse effects; D010984:Platinum / Q000009:adverse effects; D013927:Thrombosis / Q000473:pathology*; D017539:Tunica Intima / Q000473:pathology*
chemical_list: D020100:Hydrogels; D010984:Platinum