Radial forces of stents used in thoracic endovascular aortic repair and bare self-expanding nitinol stents measured ex vivo – Rapid rescue for obstruction of the innominate artery using bare self-expanding nitinol stents

Abstract

Purpose Our objective was to compare the radial forces of several stents ex vivo to identify stents suitable for rescue of the unexpected coverage of aortic arch branches in thoracic endovascular aortic repair. Methods We measured the radial forces of two types of self-expanding bare nitinol stents (E-luminexx and Epic) used singly or as double-walled pairs, and of three endoprostheses used in thoracic endovascular aortic repair (TEVAR, Gore c-TAG, Relay, and Valiant) by compressing the stent using an MTS Instron universal testing machine (model #5582). We also examined the compressive effects of the TEVAR endoprostheses and the bare nitinol stents on each other. Results The radial force was greater in the center than at the edge of each stent. In all stents tested, the radial force decreased incrementally with increasing stent diameter. The radial force at the center was two times greater when using two stents than with a single stent. In the compression test, only E-luminexx used as a pair was not compressed after compressing a Relay endoprosthesis by 12 mm. Conclusion Two E-luminexx stents are appropriate to restore the blood flow if a TEVAR endoprosthesis covers the innominate artery following innominate-carotid-left subclavian arterial bypass.

Effect of Retrievable Stent Size on Endovascular Treatment of Acute Ischemic Stroke: A Multicenter Study

“…The small size is also associated with a low stent-release force, 15 making the release of the stent smoother and safer with greater accuracy. On the other hand, the radial force decreases incrementally with increasing stent diameter, 16,17 so a small stent with a large radial force could maintain vessel wall stability during the procedure. These stent characteristics help to increase time efficiency and recanalization.…”

“…13,14 It has been reported that a difference in stent size potentially influences stent properties, including radial force, flexibility, and deliverability. [15][16][17] The radial force represents the supporting action of the stent on the vessel wall to prevent elastic retraction, while flexibility and deliverability exemplify the ability to pass through the occluded site. Several studies have found that a stent with a large radial force is suitable for proximal vessels and atherosclerotic modified vessels with hardened or calcified plaque, while a more flexible stent should be used in a tortuous or distant vessel.…”

Mechanical characterizations of braided composite stents made of helical polyethylene terephthalate strips and NiTi wires

“…The radial strength of the stent, i.e. , the capability to scaffold the stenotic lumen, is the first consideration of the stent conceptual design [ 18 , 19 ]. The BCS and BNS showed the same radial strength when the deformation is less than 20%.…”

Clinical Validation of the Impact of Branch Stent Extension on Hemodynamics in ISF-TEVAR Involving LSA Reconstruction

“…A mismatch between the main endograft and the branch stent and insufficient support of the branch stent during TEVAR will cause symptoms of arterial hemodynamics disorders ( 7 – 9 ). In parallel stent graft technology, the hemodynamic disturbance of the branch artery is usually attributed to insufficient support of the branch stent ( 10 ). To our knowledge, in clinical practice of ISF-TEVAR involving LSA reconstruction, the modification mode of the main stent and the connection between the main stent and the branch stent are not completely consistent with theoretical research.…”