Acute In-Stent Thrombosis after Carotid Angioplasty and Stenting: A Case Report and Literature Review.

Background: Based on the results of a recent randomized controlled trial, carotid artery stenting (CAS) was regarded as a relatively safe, less invasive treatment of internal carotid artery stenosis. However, cerebral thromboembolic events are the most common complications of CAS. Especially acute stent thrombosis following CAS will be fatal without prompt diagnosis and revascularization.

Case report: We report a case of acute stent thrombosis in whom carotid revascularization was performed successfully via arterial thrombolysis and balloon postdilation. A 79-year-old man with hypertension was hospitalized for an episode of transient ischemic attack. Computed tomography angiography revealed subtotal occlusion in the left carotid artery. Aspirin (100 mg) and clopidogrel (75 mg) were administered daily for 5 days before the procedure. CAS was performed under local anesthesia. The first postprocedural angiogram showed the stent looked good. However, a repeat angiogram showed in-stent thrombosis 2 min after withdrawal of the cerebral protection filter. Interestingly, the patient presented no neurologic deficit. After an additional 2,000 U of heparin had been administered intravenously, a microcatheter (SL-14; Boston Scientific, USA) was positioned to the in-stent thrombosis. Next, a total dose of 10 mg of recombinant tissue plasminogen activator was injected into the thrombus via the microcatheter within 10 min, which led to partial recanalization with antegrade flow. However, complete occlusion of the lesion occurred 5 min later. Under the guidance of angiography roadmap, a protection filter (Emboshield NAV6; Abbott Vascular, USA) was deployed at the distal part of the stent and redilation of the stent was performed with a 5 × 30 mm balloon (Viatrac 14 Plus; Abbott Vascular) at 14 atm. Finally, carotid revascularization was performed successfully, proven by postprocedural angiogram.

Conclusion: Acute carotid stent thrombosis (ACST) can have devastating effects on the survival of the patient. For ACST when the stent does not fully adhere to the blood vessel, a mechanical approach should be a feasible solution to the problem.