Abstract
Biodegradable polymers open the way to treatment of heart disease using transient implants (bioresorbable vascular scaffolds, BVSs) that overcome the most serious complication associated with permanent metal stents—late stent thrombosis. Here, we address the long-standing paradox that the clinically approved BVS maintains its radial strength even after 9 mo of hydrolysis, which induces a ∼40% decrease in the poly l-lactide molecular weight (Mn). X-ray microdiffraction evidence of nonuniform hydrolysis in the scaffold reveals that regions subjected to tensile stress during crimping develop a microstructure that provides strength and resists hydrolysis. These beneficial morphological changes occur where they are needed most—where stress is localized when a radial load is placed on the scaffold. We hypothesize that the observed decrease in Mn reflects the majority of the material, which is undeformed during crimping. Thus, the global measures of degradation may be decoupled from the localized, degradation-resistant regions that confer the ability to support the artery for the first several months after implantation.
Publisher
Proceedings of the National Academy of Sciences
Reference39 articles.
1. WHO (2010) Global Atlas on Cardiovascular Disease Prevention and Control (WHO, Geneva).
2. National Center for Health Statistics (2017) Health, United States, 2016: With chartbook on long-term trends in health (US Department of Health and Human Services, Washington, DC), DHHS Publ No 2017-1232, pp 18, 128–131.
3. Coronary Revascularization Trends in the United States, 2001-2008
4. Current Status of Bioresorbable Scaffolds in the Treatment of Coronary Artery Disease
5. Causes, assessment, and treatment of stent thrombosis—intravascular imaging insights
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