title: An Experimental Evaluation of Device/Arterial Wall Compliance Mismatch for Four Stent-Graft Devices and a Multi-layer Flow Modulator Device for the Treatment of Abdominal Aortic Aneurysms.
abstract: OBJECTIVE
  To investigate experimentally the arterial wall/device compliance mismatch of four stent-graft devices and a multilayer flow modulator within the supra- and infrarenal locations for the treatment of abdominal aortic aneurysms (AAA).
  
  
  METHODS
  Five devices (MFM, EndurantII, Excluder, Zenith, and Fortron) were tested under physiological flow conditions within a flow simulator system comprising of a patient-specific thin-walled flexible AAA perfusion model with replicated intraluminal thrombus, supported by the spinal column. Devices were submitted to circumferential force tests and implanted in the perfusion model for circumferential arterial pressure/diameter measurements. Parameters, including radial resistive force, supra-/infrarenal compliance, pulsatile arterial energy loss (PAEL), pulse wave velocity (PWV), and wave reflection coefficient (Γ), were computed to characterise the devices' performance.
  
  
  RESULTS
  The Zenith and EndurantII devices had the highest radial resistive force (up to 3 N/cm), while the Fortron device had the lowest (0.11 N/cm). Supra- and infrarenal compliance varied between 6.9-5.1 × 10(-4)/mmHg and 4.8-5.4 × 10(-4)/mmHg, respectively. Two devices (EndurantII and Excluder) significantly decreased infrarenal compliance by 13-26% (p < .001). Four devices increased the PAEL by 13-44% (p < .006). The PWV ranged from 10.9 m/s (MFM; p = .164) to 15.1 m/s (EndurantII; p < .001). There was an increase of 8-238% (p < .001) in the reflection coefficient for all devices.
  
  
  CONCLUSIONS
  Commercially available endovascular devices lower the aortic wall compliance after implantation. The MFM was found to be the most compliant in the suprarenal region, while the Fortron device was the most compliant in the infrarenal region. Choosing the most compliant devices for treating AAAs produces positive gains in the aortic elastic recoil, thus minimising the device related complications.
authors.affiliation: Galway Medical Technologies Centre (GMedTech), Department of Mechanical and Industrial Engineering, Galway Mayo Institute of Technology, Galway, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Morris
authors.affiliation: Galway Medical Technologies Centre (GMedTech), Department of Mechanical and Industrial Engineering, Galway Mayo Institute of Technology, Galway, Ireland.
authors.forename: F
authors.initials: F
authors.lastname: Stefanov
authors.affiliation: Galway Clinic, Royal College of Surgeons of Ireland Affiliated Hospital, Doughiska, Galway, Ireland.
authors.forename: N
authors.initials: N
authors.lastname: Hynes
authors.affiliation: Cardiovascular and Thoracic Surgery, Arizona Heart Foundation, Phoenix, AZ, USA.
authors.forename: E B
authors.initials: EB
authors.lastname: Diethrich
authors.affiliation: Galway Clinic, Royal College of Surgeons of Ireland Affiliated Hospital, Doughiska, Galway, Ireland; Western Vascular Institute, Department of Vascular and Endovascular Surgery, University Hospital Galway, National University of Ireland, Galway, Ireland. Electronic address: sherif.sultan@hse.ie.
authors.forename: S
authors.initials: S
authors.lastname: Sultan
mesh_terms: D001012:Aorta, Abdominal / Q000503:physiopathology / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000503:physiopathology / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D003187:Compliance; D006439:Hemodynamics; D006801:Humans; D008422:Materials Testing; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D011475:Prosthesis Failure; D063177:Pulse Wave Analysis; D012039:Regional Blood Flow; D015607:Stents; D013314:Stress, Mechanical; D059289:Vascular Stiffness
keywords: Abdominal aortic aneurysm; Compliance; Endograft; Endovascular aortic repair; Multilayer flow modulator