Abstract
Background
Carotid artery stenting (CAS) is a reasonable alternative to carotid endarterectomy, especially in patients at high risk for surgery. Carotid stent thrombosis can cause thrombembolic events, but fortunately, it is a very rare complication. We present two cases of carotid stent thrombosis and their long-term follow-up.
Case reports
One patient had severe bilateral carotid stenosis and the other had contralateral carotid occlusion. Both patients were on correct antithrombotic treatment and received balloon expandable stents (bare metal stent and drug-eluting stent). During CAS, large thrombus formed within the stent followed by rapid hemodynamic and neurological alteration. We gave a bolus thrombolytic in the clot, followed by continuous intra-arterial infusion. In one case, we performed additional angioplasty. Repeated angiography showed complete resolution of the thrombus, followed by progressive improvement in the neurological state. At discharge, the patients had no neurological deficits. CT scans revealed no acute ischemic lesions.
One patient had in-stent restenosis 3 years later, which was treated with an additional self-expandable stent.
The last follow-up was done 4 and 9 years, respectively, from the initial CAS complication. Both patients did not experience any neurological events after the last procedure.
Conclusions
Carotid stent thrombosis is a rare but potentially fatal complication following CAS. Rapid invasive diagnosis and reperfusion should be done to limit cerebral ischemia. The possible causes must be sighted and reperfusion must be started. Despite an initial dramatic course, a rapid reperfusion ensures a complete neurological recovery and a good prognosis in the long term.
1
Introduction
Carotid artery stenting (CAS) is a reasonable alternative to carotid endarterectomy, especially in high-risk surgical candidates. Thrombembolic events are the most frequent complication of CAS. Carotid stent thrombosis can cause thrombembolic events, but fortunately, it is a very rare complication. It has a major impact on immediate survival if the flow is not promptly reestablished. We present two cases of carotid stent thrombosis and their long-term follow-up.
2
Case 1
A 65-year-old male patient, who is diabetic and is a heavy smoker, with a recent transient ischemic attack (TIA) involving the right internal carotid artery (RICA), was referred to our clinic for evaluation. Bilateral internal carotid stenosis (80% on the left and 90% on the right) was diagnosed. On admission, he underwent successful CAS on RICA.
He returned 3 months later for angioplasty on the left internal carotid artery (LICA) ( Fig. 1 ).
Unfractioned heparin was administered to reach an ACT of 350 s. The short lesion on the LICA was predilated. No protection device was available at that time. After implanting an 11-mm-long ID Inflow stent (Inflow Dynamics, München, Germany) crimped on an Omnipass 4/15-mm balloon (Cordis Corporation, Warren, NJ), a significant residual stenosis was present. Therefore, we performed postdilation within the stent with a 5/10-mm-long balloon at 12 atm (Ultra-thin Diamond, Boston Scientific, Meditech, Watertown, MA). A control angiogram showed a large clot occluding the stent and a distal dissection ( Fig. 2 ). By that time, the patient complained of contralateral hemiplegia and became rapidly unconscious and hemodynamically unstable. He was intubated and started on fluids and inotropic agents. We decided to give a bolus of 100,000 IU streptokinase in the thrombus. After clot dissolution, the vessel perfusion was regained and we gave an additional 50,000 IU bolus of streptokinase ( Fig. 3 ) followed by 10,000 IU/h thereafter for 6 h through a catheter placed at the origin of the vessel. Complete clot dissolution was observed at the end of the procedure. He regained consciousness and slowly weaned of inotropes. Ultrasound (US) did not reveal any residual thrombosis or stenosis. The patient was discharged 3 days later without any neurological deficit.
Three years later, duplex US revealed significant in-stent restenosis (ISR). Because the patient was asymptomatic, we decided not to take any further actions, but after 4 months, he experienced an episode of TIA involving the LICA territory. We implanted a 6/17-mm Carotid Wallstent (Boston Scientific Ireland Ltd., Galway, Ireland), under AngioGuard (Cordis Corp., Miami, FL) protection. Postdilation was done with a 5/20-mm balloon Omnipass (Cordis Corporation). The filter was occluded at the end of the procedure, but the rest of the procedure was uneventful ( Fig. 4 ).
Nine years after the first carotid stenting, the patient is neurologically asymptomatic and duplex US shows no restenosis on both stents ( Fig. 5 ).
