stent malapposition
Incomplete contact between stent struts and the arterial wall, detected by intravascular imaging and associated with increased thrombosis risk.
Full Definition
Stent malapposition refers to the incomplete apposition of stent struts against the coronary artery wall, creating a separation between the device and vessel surface that can be detected and quantified using intravascular ultrasound or optical coherence tomography. This condition can occur acutely during implantation due to undersized stents, inadequate expansion, or vessel dissection, or develop chronically through positive vascular remodeling. Malapposition is clinically significant because it exposes metallic struts to flowing blood, increasing the risk of stent thrombosis and potentially compromising long-term patency. The condition is more common in patients with large vessel disease, bifurcation lesions, or when using oversized stents in irregular vessel segments.
Usage
Usage note: Distinguish from under-expansion; specify acute vs. late acquired when editing follow-up reports.
In Context
- "OCT imaging revealed focal stent malapposition in the proximal segment requiring post-dilatation." — Imaging assessment
- "Late acquired stent malapposition was identified as a potential mechanism for the thrombotic event." — Complication analysis