Development of bioabsorbable braided vascular scaffolds for the intracranial circulation

Jamshidi, Mehdi

Development of bioabsorbable braided vascular scaffolds for the intracranial circulation

dc.contributor.advisor	Mitha, Alim Pyarali A.
dc.contributor.advisor	Sundararaj, Uttandaraman
dc.contributor.author	Jamshidi, Mehdi
dc.contributor.committeemember	Ronsky, Janet L.
dc.contributor.committeemember	Di Martino, Elena S.
dc.date	2019-11
dc.date.accessioned	2019-06-05T20:20:41Z
dc.date.available	2019-06-05T20:20:41Z
dc.date.issued	2019-05-29
dc.description.abstract	An intracranial (or brain) aneurysm is a life-threatening disease that affects more than 3% of the population. The treatment techniques of cerebral aneurysms have significantly improved in the past decade, transitioning from open surgical procedures to less invasive endovascular procedures. A disruptive technology in aneurysm treatment was the advent of the metal flow-diverting stent, which made it relatively easy to treat the most complicated of brain aneurysms, and avoiding the need for a high-risk open surgical procedure. Despite these improvements, metal stents are still associated with major complications, mostly due to their thrombogenicity as well as their long-term implications. Although the need for a stent to treat aneurysms is only temporary, due to progressive neointima formation over the stent structure, they cannot be removed. This requires patients to remain on lifelong anti-platelet medications, which can cause other health problems. Bioabsorbable stents have been postulated as a way to overcome the long-term disadvantages of metal stents. Commercial bioabsorbable stents have been developed for coronary artery diseases, although the design of coronary stents is different than for intracranial aneurysms. Coronary stents are mostly balloon expandable, and can acquire good wall apposition simply by balloon inflation. Stents used for intracranial applications, on the other hand, are required to be flexible and self-expandable, and they should revert to at least close to their original diameter after deployment from the catheter. The challenges for the design of bioabsorbable flow-diverting stents for the treatment of intracranial aneurysms lies in differences with the deployment mechanism, the poor mechanical properties of bioabsorbable polymers, and their inability to show shape memory behavior. In this study, we designed and fabricated bioabsorbable flow-diverting stents for the treatment of aneurysms. Information acquired from existing stents, as well as the three initial iterations of our design, are reviewed and discussed. The mechanical properties and safety profile of our stents were studied in vitro, and the safety and efficacy were also studied in vivo with pilot animal experiments. The bioabsorbable flow-diverting stent that we developed demonstrated mechanical properties similar to existing intracranial stents. They further showed low potential for hemolysis and thrombus formation on the stent struts, as well as neointimal layer formation and persistent side branch patency in animal models at 1 month follow-up. The performance of the stent in terms of flow-diverting capabilities was also demonstrated in acute small and large animal models of intracranial aneurysms.	en_US
dc.identifier.citation	Jamshidi, M. (2019). Development of bioabsorbable braided vascular scaffolds for the intracranial circulation (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/36621
dc.identifier.uri	http://hdl.handle.net/1880/110472
dc.language.iso	eng	en_US
dc.publisher.faculty	Schulich School of Engineering	en_US
dc.publisher.institution	University of Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.	en_US
dc.subject	Intracranial aneurysm, Flow-diverting stent, Bioabsorbable stent	en_US
dc.subject.classification	Engineering--Biomedical	en_US
dc.title	Development of bioabsorbable braided vascular scaffolds for the intracranial circulation	en_US
dc.type	doctoral thesis	en_US
thesis.degree.discipline	Engineering – Biomedical	en_US
thesis.degree.grantor	University of Calgary	en_US
thesis.degree.name	Doctor of Philosophy (PhD)	en_US
ucalgary.item.requestcopy	true