Midterm Results of the Use of Low Profile Multibranched Thoracoabdominal Aortic Stent Grafts

Ramanan, Bala; Fernandez, Charlene C.; Sobel, Julia D.; Gasper, Warren J.; Vartanian, Shant M.; Reilly, Linda M.; Chuter, Timothy A.M.; Hiramoto, Jade S.

doi:10.1016/j.jvs.2015.06.013

Cited by 2 publications

(1 citation statement)

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“…Table 3 shows the diameter of the stress-free stent configuration, the DEDL and the crimped diameter for the three device designs under consideration. The crimp diameter is based on the use of a standard commercially available 22F delivery system (Ramanan et al 2015 ). In all cases, the crimped device is deployed at section 6 of the subject-specific aortic model, where the vessel area is 184 mm 2 at the diastolic pressure of 73 mmHg and 247 mm 2 at the peak systolic pressure of 117 mmHg.…”

Section: Model Developmentmentioning

confidence: 99%

Influence of shape-memory stent grafts on local aortic compliance

Concannon

Moerman

Hynes

et al. 2021

Biomech Model Mechanobiol

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The effect of repair techniques on the biomechanics of the aorta is poorly understood, resulting in significant levels of postoperative complications for patients worldwide. This study presents a computational analysis of the influence of Nitinol-based devices on the biomechanical performance of a healthy patient-specific human aorta. Simulations reveal that Nitinol stent-grafts stretch the artery wall so that collagen is stretched to a straightened high-stiffness configuration. The high-compliance regime (HCR) associated with low diastolic lumen pressure is eliminated, and the artery operates in a low-compliance regime (LCR) throughout the entire cardiac cycle. The slope of the lumen pressure–area curve for the LCR post-implantation is almost identical to that of the native vessel during systole. This negligible change from the native LCR slope occurs because the stent-graft increases its diameter from the crimped configuration during deployment so that it reaches a low-stiffness unloading plateau. The effective radial stiffness of the implant along this unloading plateau is negligible compared to the stiffness of the artery wall. Provided the Nitinol device unloads sufficiently during deployment to the unloading plateau, the degree of oversizing has a negligible effect on the pressure–area response of the vessel, as each device exerts approximately the same radial force, the slope of which is negligible compared to the LCR slope of the native artery. We show that 10% oversizing based on the observed diastolic diameter in the mid descending thoracic aorta results in a complete loss of contact between the device and the wall during systole, which could lead to an endoleak and stent migration. 20% oversizing reaches the Dacron enforced area limit (DEAL) during the pulse pressure and results in an effective zero-compliance in the later portion of systole.

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Section: Model Developmentmentioning

confidence: 99%