title: In vitro studies for stent-assisted coiling of terminus aneurysms by straight-on intra-aneurysmal stent deployment.
abstract: OBJECTIVE
  Deployment of a Neuroform microstent (NFM; Boston Scientific/Target, Freemont, California, USA) within acutely angled geometry may result in substantial deformations. This in vitro study was conducted to validate a novel alternative technique, consisting of intentional deployment of a NFM straight on into a terminus aneurysm, by assessing the mechanics, feasibility, and stability of the coils.
  
  
  METHODS
  Silicon models of wide-neck terminus aneurysms were constructed. Straight-on deployment of a NFM from the afferent vessel into the aneurysm was compared with conventional cross-neck deployment at a right angle position followed by Guglielmi detachable coil embolization simulation. The supporting forces of the two different methods of deployment were compared by the use of side-wall eccentric and en-face compression tests.
  
  
  RESULTS
  Straight-on deployment of a NFM at a wide-neck terminus aneurysm was a relatively simple technique compared with cross-neck right angle deployment. Good stability of the coil mass was consistently achieved with adequate preservation of the parent vessel lumen. A larger residual neck space at the side without the stent and much coil mass protruding into the parent vessel were observed in cross-neck stent deployment. Compression tests revealed a larger supporting force of the NFM with straight-on deployment compared with the side-wall radial force (P < 0.05). A potential problem with this technique is the possible inability or difficulty in retrieving a partially deployed coil.
  
  
  CONCLUSIONS
  Stent-assisted coiling of wide-neck terminus aneurysms with straight-on deployment of NFM consistently achieved a stable NFM-coil complex. The NFM also had a better supporting force in a straight position. Some technical difficulties may be encountered during subsequent coiling. This alternative technique to conventional cross-neck bridging appears to be another strategy for wide-neck terminus aneurysm coiling.
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taiwan, Republic of China. Electronic address: hsusw@adm.cgmh.org.tw.
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Hsu
authors.forename: John C
authors.initials: JC
authors.lastname: Chaloupka
authors.forename: Mitsuyuki
authors.initials: M
authors.lastname: Fujitsuka
mesh_terms: D001807:Blood Vessel Prosthesis; D004867:Equipment Design; D005240:Feasibility Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008422:Materials Testing; D055595:Mechanical Phenomena; D019635:Neurosurgical Procedures / Q000379:methods; D012825:Silicon; D015607:Stents
chemical_list: D012825:Silicon
keywords: GDC; Guglielmi detachable coil; Intracranial aneurysm; Model; NFM; Neuroform microstent