title: Clinical Results and Mechanical Properties of the Carotid CGUARD Double-Layered Embolic Prevention Stent.
abstract: To report early clinical outcomes with a novel double-layer stent for the internal carotid artery (ICA) and the in vitro investigation of the stent's mechanical properties.
  
  
  
  A prospective single-center study enrolled 30 consecutive patients (mean age 73.1±6.3 years; 21 men) with symptomatic (n=25) or high-grade (n=5) ICA stenosis treated with the new double-layer carotid CGUARD Embolic Prevention System (EPS) stent, which has an inner open-cell nitinol design with an outer closed-cell polyethylene terephthalate layer. The average stenosis of the treated arteries was 84.1%±7.9% with a mean lesion length of 16.6±2.1 mm. In the laboratory, 8×40-mm stents where tested in vitro with respect to their radial force during expansion, the bending stiffness of the stent system and the expanded stent, as well as the collapse pressure in a thin and flexible sheath. The wall adaptation was assessed using fluoroscopy after stent release in step and curved vessel models.
  
  
  
  The stent was successfully implanted in all patients. No peri- or postprocedural complications occurred; no minor or major stroke was observed in the 6-month follow-up. The bending stiffness of the expanded stent was 63.1 N·mm2and (not unexpectedly) was clearly lower than that of the stent system (601.5 N·mm2). The normalized radial force during expansion of the stent to 7.0 mm, consistent with in vivo sizing, was relatively high (0.056 N/mm), which correlates well with the collapse pressure of 0.17 bars. Vessel wall adaptation was harmonic and caused no straightening of the vessel after clinical application.
  
  
  
  Because of its structure, the novel CGUARD EPS stent is characterized by a high flexibility combined with a high radial force and very good plaque coverage. These first clinical results demonstrate a very safe implantation behavior without any stroke up to 6 months after the procedure.
authors.affiliation: 1 Institute of Diagnostic and Interventional Radiology/Neuroradiology, Westkuestenklinikum Heide-Academic Teaching Hospital of the Universities of Kiel, Luebeck, and Hamburg, Heide, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wissgott
authors.affiliation: 2 Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Schmidt
authors.affiliation: 2 Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Brandt-Wunderlich
authors.affiliation: 2 Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Behrens
authors.affiliation: 1 Institute of Diagnostic and Interventional Radiology/Neuroradiology, Westkuestenklinikum Heide-Academic Teaching Hospital of the Universities of Kiel, Luebeck, and Hamburg, Heide, Germany.
authors.forename: Reimer
authors.initials: R
authors.lastname: Andresen
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000503:physiopathology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D057505:Embolic Protection Devices; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008422:Materials Testing; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
keywords: carotid artery stent; closed-cell design; double-layer stent; embolic filter; in vitro testing; internal carotid artery; mechanical behavior; nitinol; open-cell design; radial force; stenosis; stent