title: Aspirin and Clopidogrel Inhibit Aneurysm Healing after HydroCoil Implantation in External Carotid Artery Aneurysm Model.
abstract: OBJECTIVE
  To understand whether the use of antiplatelet agents leads to less intra-aneurismal tissue formation following coil implantation in a rat end-pouch external carotid artery (ECA) aneurysm model.
  
  
  METHODS
  End-pouch ECA aneurysms were created in adult rats and were then embedded with either platinum or HydroCoils. Rats were treated either with aspirin, clopidogrel, aspirin + clopidogrel, or saline for 2 weeks after coil implantation. At 2 weeks after coil implantation, rats were sacrificed and the aneurysm pouch was removed for histological and immunohistochemical analysis. A blinded single observer calculated the percentage of the organized area and the residual length of elastic lamina within the aneurysm. Student's t-test was used to compare data from image analysis between the different groups.
  
  
  RESULTS
  Within the platinum group, the organized tissue area was not affected by antiplatelet administration (aspirin versus saline, P = .83; clopidogrel versus saline, P = .46; aspirin + clopidogrel versus saline, P = .54). For the HydroCoil group, the organized tissue area was significantly reduced (aspirin versus saline, P = .02; clopidogrel versus saline, P = .04; aspirin + clopidogrel versus saline, P = .02) in rats treated with antiplatelet agents; however, no difference (aspirin versus clopidogrel, P = .8; aspirin versus aspirin + clopidogrel, P = .3; clopidogrel versus aspirin + clopidogrel, P = .5) was found among type or combination of antiplatelets administered. HydroCoil-treated aneurysms had a similar number of macrophages compared to the platinum group (P = .3819); however, the HydroCoil group had significant suppression of macrophages in the groups treated with combined antiplatelets (P = .02).
  
  
  CONCLUSIONS
  Following HydroCoil implantation, the area of organized tissue is diminished significantly in a rat end-pouch ECA aneurysm model treated with antiplatelets.
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Peiliang
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xi
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Gemmete
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Chaudhary
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: B Gregory
authors.initials: BG
authors.lastname: Thompson
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan. Electronic address: adityap@med.umich.edu.
authors.forename: Aditya S
authors.initials: AS
authors.lastname: Pandey
mesh_terms: D000783:Aneurysm / Q000473:pathology / Q000628:therapy*; D000818:Animals; D001241:Aspirin / Q000633:toxicity*; D002340:Carotid Artery Diseases / Q000473:pathology / Q000628:therapy*; D002342:Carotid Artery, External / Q000187:drug effects* / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects; D000077144:Clopidogrel; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D004867:Equipment Design; D008264:Macrophages / Q000187:drug effects / Q000473:pathology; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000633:toxicity*; D010984:Platinum; D017207:Rats, Sprague-Dawley; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000633:toxicity; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D010975:Platelet Aggregation Inhibitors; D010984:Platinum; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin
keywords: Antiplatelet medications; aspirin; clopidogrel; coiling; rat experimental aneurysms