title: Cellular responses of bioabsorbable polymeric material and Guglielmi detachable coil in experimental aneurysms.
abstract: OBJECTIVE
  Acceleration of healing mechanisms is a promising approach to improve current limitations of endovascular aneurysm therapy with the use of platinum coils. We evaluated a new endovascular therapeutic, bioabsorbable polymeric material (BPM), which may promote cellular reaction in the aneurysms.
  
  
  METHODS
  Four different concentrations of lactide/glycolic acid copolymer [poly(D-L-lactic-co-glycolic acid)] (PLGA), 85/15, 75/25, 65/35, and 50/50, were used as BPMs. Sixteen experimental aneurysms were created in 8 swine. Eight-millimeter-long spiral-shaped BPMs were surgically implanted in the aneurysms without tight packing (n=3 for each BPM). Guglielmi detachable coils (GDCs) were used as control (n=4). The animals were killed 14 days after embolization, and angiographic, histological, and immunohistochemical analyses were performed.
  
  
  RESULTS
  Despite loose packing of aneurysms with BPMs, faster BPMs such as 50/50 or 65/35 PLGA demonstrated more mature collagen formation and fibrosis in the sac and neck of the aneurysm. One aneurysm treated with 65/35 PLGA, 1 treated with 75/25 PLGA, and all 3 treated with 85/15 PLGA showed a neck remnant on angiography. There was a linear relationship between collagen levels and polymer degradation properties (r=-0.9513).
  
  
  CONCLUSIONS
  This preliminary animal study indicates that acceleration of aneurysm healing with the use of BPM is feasible. This concept can be applied to decrease and perhaps prevent aneurysmal recanalization after endovascular treatment of cerebral aneurysms.
authors.affiliation: Division of Interventional Neuroradiology, Department of Radiological Sciences, Molecular Biology Institute, University of California at Los Angeles 90095, USA. ymurayama@mednet.ucla.edu
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Murayama
authors.forename: Fernando
authors.initials: F
authors.lastname: Viñuela
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tateshima
authors.forename: Nestor R
authors.initials: NR
authors.lastname: Gonzalez
authors.forename: Joon K
authors.initials: JK
authors.lastname: Song
authors.forename: Haleh
authors.initials: H
authors.lastname: Mahdavieh
authors.forename: Luisa
authors.initials: L
authors.lastname: Iruela-Arispe
mesh_terms: D020341:Absorbable Implants / Q000009:adverse effects; D000783:Aneurysm / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D000792:Angiography; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D001807:Blood Vessel Prosthesis / Q000009:adverse effects; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods; D002340:Carotid Artery Diseases / Q000150:complications / Q000473:pathology / Q000601:surgery*; D017536:Carotid Artery, Common / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D024042:Collagen Type I / Q000378:metabolism; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000295:instrumentation / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D005355:Fibrosis / Q000209:etiology; D005549:Foreign-Body Reaction / Q000209:etiology; D007150:Immunohistochemistry; D020007:Implants, Experimental / Q000009:adverse effects; D019344:Lactic Acid / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D011100:Polyglycolic Acid / Q000737:chemistry / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology; D013552:Swine; D013927:Thrombosis / Q000209:etiology; D014945:Wound Healing / Q000187:drug effects
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid