A Rare Case of Coronary Stent Fracture in a Patient with Kawasaki’s Disease

Abstract

Stent fracture is a rare complication of coronary stents, occurring primarily in first-generation drug-eluting stents compared to second-generation stents. We present herein a rare case of stent fracture in a patient with Kawasaki’s disease that was managed with superimposed stent placement, along with adjunctive intravascular ultrasound imaging.

Case

A Caucasian female with Kawasaki’s disease and familial dyslipidemia presented initially at the age of 21 years to an outside hospital with chest pain. Laboratory analysis was remarkable for positive cardiac enzymes. Electrocardiogram demonstrated ST depressions in the anterior leads. Coronary angiography revealed ectatic coronary arteries with mid left anterior descending coronary artery (LAD) 80% stenosis (Figure 1) that was determined to be the culprit lesion for her symptoms. Percutaneous coronary intervention was performed using a Cypher 3.5 x 18 mm stent (Cordis Corporation) and post-dilated to 4.0 mm after intravascular ultrasound (IVUS) imaging with good angiographic result (Figure 2) and discharged home the following day.

Four years later, the patient presented with progressive angina and dyspnea on exertion. An exercise nuclear stress test demonstrated reproducible exertional angina with moderate anterior ischemia. Subsequent coronary angiography revealed a type V stent fracture in the mid LAD with transsection of the stent and displacement of the two stent fragments, with 80% stenosis within the gap (Figure 3). IVUS imaging confirmed the fluoroscopic findings of stent fracture and displacement (Figure 4). After pre-dilation, a Taxus Liberte 3.5 x 38 mm stent (Boston Scientific) was deployed, including the stent fragments and the gap, and post-dilated to 4.0 mm with adjunctive IVUS imaging (Figure 5). The patient was discharged home the following day on dual antiplatelet therapy and has been in follow-up for two years without recurrence of symptoms.

Discussion

Stent fracture is a rare complication of PCI with stents, and occurs in 1% to 8% of patients.¹ The incidence of stent fracture has been reported to be almost five times higher in first-generation DES compared to second-generation DES.² Meanwhile, the prevalence of stent fracture in bare metal stents is unknown. Consequences of stent fracture include in-stent restenosis, stent thrombosis, coronary aneurysm, or sudden cardiac death.³ Stent fracture has been associated with excessive tortuosity or angulation of vessels, right coronary artery stents, overlapping stents, and long stents.⁴ Additional technical factors include inappropriate handling, high-pressure deployment, stenting in calcified segments, and manufacturing flaws, including use of stents with greater predisposition to stent fracture.

Stent fracture has been classified into 5 grades: I (single-strut fracture), II (≥2 strut fracture), III (≥2 strut fracture with deformation), IV (fracture with transsection but without gap), and V (fracture with transsection and gap between stent segments).⁵

Stent visibility is limited on conventional fluoroscopic imaging, further decreased by patient body habitus, stent platform, and stent thickness.³ Earlier generation stainless-steel stents have a strut thickness of up to 0.0055 inches, yielding good fluoroscopic visibility compared to newer generation cobalt-chromium stents with strut thickness as low as 0.0032 inches, which reduces fluoroscopic visibility. However, technological advances in software for acquisition of enhanced images in the catheterization laboratory allow improved visibility of stent struts⁶ and detection of stent fracture.⁷ Additionally, stent fracture is readily detectable with the use of adjunctive imaging techniques such as computed tomography8, intravascular ultrasound9 and optical coherence tomography.¹⁰

We describe herein a rare case of stent fracture in a patient with Kawasaki’s disease, confirmed using intravascular ultrasound, and managed successfully using a superimposed newer-generation DES.

Dr. Jon George may be contacted at georgej@deborah.org.

References

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Disclosure: Dr. George reports he is a consultant for Boston Scientific.