title: Response of Wallstents to dilation: therapeutic implications.
abstract: OBJECTIVE
  The authors document the degree of in vitro shortening of the Wallstent when expanded to different diameters and demonstrate the clinical importance of this property.
  
  
  METHODS
  Forty-two-, 68- and 94-mm size Wallstents were expanded within cylinders that were 6, 8, 10, and 12 mm in diameter, and their lengths were measured.
  
  
  RESULTS
  Progressive stent shortening occurred between diameters of 6 and 10 mm. Extreme shortening occurred at overdilation to 12 mm: At this diameter a 42-mm stent is 24.5 mm long (vs 46 mm at a 10-mm diameter), a 68-mm stent is 40 mm (vs 65 mm), and a 94-mm stent is 64 mm (vs 95 mm).
  
  
  CONCLUSIONS
  Specific knowledge of stent lengths at different diameters is required for proper stent choice and accurate deployment. Over-dilation to a 12-mm diameter is useful in correcting excessive stenting and resistant stent narrowings, but it can result in excessive shortening requiring additional stent placement.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Haskal
authors.forename: J M
authors.initials: JM
authors.lastname: LaBerge
authors.forename: R L
authors.initials: RL
authors.lastname: Gordon
authors.forename: J
authors.initials: J
authors.lastname: Gonzales
mesh_terms: D001696:Biomechanical Phenomena; D004106:Dilatation; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D011170:Portasystemic Shunt, Surgical / Q000295:instrumentation; D015607:Stents