A new method for assessing neointimal coverage after drug-eluting stent implantation using three-dimensional optical coherence tomography

Abstract

Background

A novel 3-dimensional (3D) optical coherence tomography (OCT) method was developed for assessing volumetric neointimal formation and for evaluating the distribution of uncovered or malapposed struts in implanted drug-eluting stents (DES).

Methods

A total of 15 DESs (10 sirolimus-eluting stents [SES] and 5 zotarolimus-eluting stents [ZES]) were evaluated by frequency-domain OCT. Cross-sectional OCT images were collected at 0.2-mm intervals. The neointimal thickness within a whole stent was measured as a function of the circumferential arc length and longitudinal stent length. Computer-generated contour plots of the neointimal thickness were used to evaluate stent structure, and each stent strut was categorized as covered-apposed, uncovered-apposed, uncovered-malapposed, or side-branch.

Results

The degree of neointimal growth and the presence of any stent structure deformity were displayed on the contour maps (See the representative figures of SES). DES displayed varied patterns in the geographic distribution of the uncovered and malapposed struts. Notably, all SES had diffusely scattered uncovered struts, whereas only 40% of ZES displayed focally distributed uncovered struts.

Conclusion

This 3D volumetric OCT assessment of the coronary vascular wall provides a powerful new approach for evaluating and tracking neointimal hyperplastic events in implanted vascular stents.