title: Gas generation and clot formation during electrolytic detachment of Guglielmi detachable coils: in vitro observations and animal experiment.
abstract: OBJECTIVE
  Recent reports describe a high rate of thromboembolic events related to Guglielmi detachable coil (GDC) use in the treatment of cerebral aneurysms. The purpose of this study was to investigate electrolysis-related changes of blood as a potential cause of thromboembolic complications associated with GDC use.
  
  
  METHODS
  For in vitro observations, 15 GDCs (10 conventional coils and five insulated coils) were experimentally detached under microscopic observation. Three coils were detached in normal saline, five in human serum, and seven in heparinized human blood. For animal experiments, two coils were detached in two canine normal common carotid arteries with systemic heparinization. Immediately after detachment, the arteries were exposed, and clot formations were observed.
  
  
  RESULTS
  Significant amounts of gas bubbles were observed in all in vitro observations; more were seen in conventional coils, which required longer detachment times, than in insulated coils. Gas generation started with the growth of tiny bubbles into larger ones. In insulated coils, gas was generated only at the detachment zone, and no difference between saline, serum, and blood environments was observed. During detachment within heparinized blood, clot formations of 2-3-mm diameter were observed at the detachment zones of insulated coils. Animal experiments showed clot formation at the detachment zone, and bubble entrapments around the clots were also found.
  
  
  CONCLUSIONS
  The electrolytic detachment mechanism of the platinum coil can generate gas bubbles during the application of electric current. In association with electrothrombosis, this phenomenon may be a potential cause of thromboembolic complications during the treatment of cerebral aneurysms by use of GDCs.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Korea.
authors.forename: Moon Hee
authors.initials: MH
authors.lastname: Han
authors.forename: O-Ki
authors.initials: OK
authors.lastname: Kwon
authors.forename: Chang Jin
authors.initials: CJ
authors.lastname: Yoon
authors.forename: Bae Joo
authors.initials: BJ
authors.lastname: Kwon
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Cha
authors.forename: Kee-Hyun
authors.initials: KH
authors.lastname: Chang
mesh_terms: D000818:Animals; D001769:Blood; D002339:Carotid Arteries / Q000473:pathology; D004285:Dogs; D004572:Electrolysis / Q000009:adverse effects*; D004618:Embolism, Air / Q000209:etiology*; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D066298:In Vitro Techniques; D020766:Intracranial Embolism / Q000209:etiology*; D018570:Risk Assessment; D012965:Sodium Chloride
chemical_list: D012965:Sodium Chloride