How we arrived here: understanding the BVS bioresorbable coronary scaffold today
The special article by Patrick W. Serruys and Yoshinobu Onuma on the impact of implantation techniques for the BVS bioresorbable coronary scaffold deserves a word of introduction.
The reader should not feel discouraged by a technical title, that uses several acronyms (Dmax or PSP 1-2-3), whose meaning was unknown until recently. Instead, this article is a unique essay, providing a detailed account of the journey of this truly novel technology, including both the happy milestones as well as the bumps along the way. The content of the article is unusual: it reads like an editorial, but there is more. It reads like a review, but there is more. As such, it provides detailed narratives following how our thinking has evolved with each new discovery, how key decisions were made at the crossroads and how these decisions have had an impact on present outcomes.
“Insider” views on the process of innovation and development are almost never publicly available. Disclosure of essential source documents are essential in understanding how findings and events were linked to each other. The article provides unique illustrations, whereby detailed imaging helps us understand the previously unknown mechanisms and timelines of the bioresorption processes.
Enhanced publication of this exceptional and unusual piece is justified by the importance and novelty of the material. I trust that you will enjoy reading this unique and thoughtful historical account of the many years of research and clinical evaluation that have gone into bioresorbable technologies since their inception, provided by two of the most acknowledged actors and privileged witnesses in this domain.
This special EEP/Editorial is published in association with 2 articles of specific interest on this subject:
- “Predilation, sizing and post-dilation scoring in patients undergoing everolimus-eluting bioresorbable scaffold implantation for prediction of cardiac adverse events: development and internal validation of the PSP score” by Luiz Ortega-Paz et al.
- “Five-year follow-up of underexpanded and overexpanded bioresorbable scaffolds: self-correction and impact on shear stress” by Ryo Torii et al. - Interventional Flashlight - a new EuroIntervention section.
Figure 11. Post-procedural shear stress in underexpanded and overexpanded scaffold and its long-term evolution (at five years). The wall shear stress simulations in a case of an underexpanded (left) and overexpanded scaffold (right), combining three-dimensional angiography and optical coherence tomography. In the case of underexpansion (left), post-implantation lumen showed a step down and step up at the proximal and distal edges of the bioresorbable scaffold. The proximal underexpanded part of the device causes relatively high shear stress of >5 Pa on top of the proximal struts, whereas the part of the scaffold normally expanded exhibits low shear stress of 0.5-1.0 Pa between the struts. The high shear stress initially observed in the proximal part of the scaffold was, at five years, no longer present as a result of dynamic remodelling and lumen enlargement. In the overexpanded scaffold case (right), the inter-strut shear stress was very low (<1 Pa). At five years, the very low shear stress was no longer observed69. In both cases at five years, the lumen exhibited a smooth endoluminal surface, and accordingly the shear stress distribution became more homogenous and physiological 56,70,71. Pa: pascal unit of shear stress.