Abstract 19579: An Experimental Evaluation of the Compliance Mismatch Effects for Four Stent-graft Devices and a Multi-layer Flow Modulator (MFM) Device for the Treatment of Abdominal Aortic Aneurysms

Abstract

Purpose: To experimentally investigate the arterial wall/device compliance mismatch of four stent-graft devices and a multi-layer flow modulator within the supra- and infra-renal locations for the treatment of Abdominal Aortic Aneurysms (AAA). Methods: Five devices were tested under physiologically flow conditions within a flow simulator system comprising of a patient-specific thin-walled flexible AAA model with replicated intraluminal thrombus (ILT) supported by the spinal column. Arterial pressure/diameter measurements were monitored and recorded at the supra- and infra-renal regions and various hemodynamic indicators were obtained to assess the effects of compliance mismatch. Results: At the suprarenal region, all devices except the Excluder™, significantly decreased the compliance by 10 - 21% (p<0.002) and increased the stiffness values by 5 - 21% (p<0.001). At the infrarenal region, three devices (Endurant™ and Excluder™) significantly decreased the compliance by 13 - 26% (p<0.001), while the other three devices (MFM™, Zenith™ and Fortron™) did not significantly change the aortic compliance (p>0.057). There was a variation of 10.9 - 16.0 m/s in pulse wave velocities with an increase of 8 - 238% (p<0.001) in the reflection coefficient for all devices. The Excluder™ and Endurant TM devices doubled the infrarenal unstented median elastic modulus value (p<0.001). Conclusions: Commercially available endovascular devices lower the arterial wall compliance and increase the wall stiffness at the stent/arterial wall interface by varying amounts. The Excluder™ was found to be the most compliant in the surprarenal region, while the MFM™ device was the most compliant in the infrarenal region.