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Published on: September 14, 2009
Persistent malapposition after implantation of sirolimus-eluting stent into intramural coronary hematoma: optical
Takahiro Sawada1, Junya Shite, Toshiro Shinke
1Department of Internal Medicine, Division of Cardiovascular and Respiratory Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
Insights
Sirolimus-eluting stents (SES) for intramural hematoma after percutaneous coronary intervention (PCI) may cause late stent malapposition due to vessel enlargement. Optical coherence tomography (OCT) aids in precise assessment.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Biomedical Engineering
Background:
- Anterior myocardial infarction (MI) in a 76-year-old male patient with severe left anterior descending (LAD) artery stenosis and left circumflex artery (LCX) occlusion.
- Initial successful percutaneous coronary intervention (PCI) on LAD segment 7.
- Attempted staged PCI on LCX using a distal protection system resulted in subintimal wire traversal, leading to significant dissection and intramural hematoma.
Observation:
- Implantation of three sirolimus-eluting stents (SES) to cover the intramural hematoma.
- Intravascular ultrasound (IVUS) at 2 weeks revealed stent malapposition and vessel enlargement, despite hematoma healing.
- Optical coherence tomography (OCT) provided clearer visualization of the malapposition.
Findings:
- Initial balloon dilatation achieved stent apposition, but recurrence of malapposition was observed at 6 months.
- The recurrent malapposition was characterized by thrombus-like tissue covering the stent struts.
- Persistent vessel enlargement, attributed to arterial wall injury and SES-mediated inhibition of neointimal hyperplasia, is suggested as the cause of late malapposition.
Implications:
- Sirolimus-eluting stents may contribute to late stent malapposition in the context of treating large intramural hematomas.
- Optical coherence tomography is a valuable tool for detailed assessment of stent strut apposition and vessel morphology.
- Understanding the mechanisms of late malapposition is crucial for optimizing PCI strategies in complex coronary lesions.
Abstract:
A 76-year-old man presented with an anterior myocardial infarction. Coronary angiography showed 99% stenosis in the left anterior descending artery and total occlusion in the left circumflex artery (LCX). After successful percutaneus coronary intervention (PCI) for segment 7, a staged PCI to the LCX with a distal protection system was attempted, but the wire entered the subintima, creating a large dissection and intramural hematoma. Three sirolimus-eluting stents (SES) were implanted to cover the entire hematoma, but 2 weeks later intravascular ultrasound revealed stent malapposition, with healing of the residual hematoma, and vessel enlargement. Optical coherence tomography (OCT) showed the malapposition more clearly. Balloon dilatation successfully achieved apposition of the SES to the vessel wall, but 6 months later it revealed recurrence of malapposition, with the struts covered by thrombus-like tissue. This case suggests that SES implantation treatment of a long intramural hematoma can potentially cause late malapposition because of persistent vessel enlargement related to arterial wall injury and inhibition of neointimal hyperplasia by the SES. OCT is useful in showing the precise condition of the stent struts.
