The study protocol was approved by the Ethics Committees of the Fifth People's Hospital of Chengdu, Chengdu, and the patient provided written informed consent.
The 69-year-old man was admitted to the Fifth People's Hospital of Chengdu, Chengdu, China for weakness of right limb, right central facial paralysis, and hemianalgesia for 2 days. The weakness of his right limb was aggravated, and barylalia was detected for a half of day. He had a history of hypertension for four years due to poor blood pressure control. After hospitalization, magnetic resonance imaging (MRI) showed multiple internal border zone infarcts in a rosary-like pattern along the left centrum semiovale. A computed tomography (CT) angiography showed severe stenosis at the beginning of the left internal carotid artery (LICA) (Figure 1). His platelet count was 107x109/L, and his coagulation function was normal. After multidisciplinary consultation, including Cardiology, Respiratory Medicine, Neurosurgery, and Anesthesiology, anesthesiologists believed that the risk of general anesthesia was greater due to poor lung function in the patient, resulting in left carotid stenting rather than endarterectomy for secondary prevention. Before the surgery, the patient took aspirin (100 mg) and clopidogrel (75 mg) for 5 days, and atorvastatin (20 mg) was routinely administered for 5 days. The National Institute of Health Stroke Scale (NIHSS) score of the patient was 5.
CAS was performed under local anesthesia. Heparin was administered intravenously at a dose of 5,000 U (100 U/kg) bolus immediately after femoral artery puncture and at a dose of 1,000 U/h during the procedure. Angiography revealed 90% stenosis in the left carotid artery according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. First, we positioned a distal protection device (spider FX; eV3 Inc., Plymouth, MN, USA), and the stenosis of the left internal carotid artery was then predilated with a 5 x 30 mm balloon (Viatrac 14 Plus; Abbott Vascular, Temecula, CA, USA). A 7 × 40 mm self-expandable carotid stent (Wallstent; Boston Scientific, Marlborough, MA, USA) was then placed by a 0.014-inch guidewire and an 8-F guide catheter. In addition, the CAS was performed without any complications (Figure 2), and the patient did not show any symptoms during the CAS procedure.
After the surgery, the patient continued to take aspirin 100 (mg), clopidogrel (75 mg), and atorvastatin (20 mg). One day after surgery, we assayed his platelet count and coagulation function as a routine procedure. His platelet count and coagulation function were both in the normal range. Additionally, the patient did not complain about any discomfort. Five days after surgery, the patient showed lethargy, gaze to the left-side, motor aphasia, and right hemiplegia, and the patient’s NIHSS score was 18. After 30 minutes, CT angiography showed acute stent thrombosis of the left internal carotid artery (Figure 3).
We performed thrombus aspiration via right percutaneous transfemoral access under local anesthesia. After the 8F guiding catheter (Boston Scientific, Marlborough, MA, USA) was placed, the angiography showed acute thrombosis at the proximal end of the stent without forward blood flow. The Synchro2 Microwire (Stryker, Kalamazoo, MI, USA) with a Rebar 18 microcatheter (ev3 Inc., Irvine, CA, USA) showed thrombosis in the M1 segment. We preferential opening of the MCA blood vessel was conducted through a 4 × 20 mm Solitaire FR (ev3 Inc., Irvine, CA, USA) stent with a thrombus approximately 2-3 cm long(Figure 5). A 6F Navien (ev3 Inc., Irvine, CA, USA) was used to enter the stent thrombus for thrombus aspiration, and a thrombus of approximately 4 cm in length was aspirated as well (Figure 5). After the angiography, the blood flow in the stent was partially restored, but the forward blood flow was still slow. A Spider distal protection device was positioned (ev3 Inc., Irvine, CA, USA), and a 5 × 30 mm balloon (Boston Scientific, Marlborough, MA, USA) was expanded twice by 12 atm. The angiography showed a significant improvement in the anterior blood flow, but there was some thrombus in the stent. Tirofiban (10 ml) was given through a Rebar 18 microcatheter (ev3 Inc., Irvine, CA, USA). The angiography then showed complete disappearance of the thrombus and complete recovery of forward blood flow (Figure 5). After surgery, the patient's NIHSS score was 12.
The postoperative CT showed severe cerebral edema and contrast agent leakage without hemorrhage. Two days after thrombus aspiration, the CT angiography showed complete recanalization of the stent, and most of the contrast agents were absorbed. Four days after the second surgery, however, the CT showed a slight hemorrhage in the basal ganglia and cerebral edema around the hemorrhage area. Regarding stent thrombosis, the patient continued to take aspirin, clopidogrel, and atorvastatin. Ten days after the second surgery, we found out that the patient is a CYP2C19*2 heterozygote. Thus, we gave the patient a triple dose of clopidogrel compared to the preoperative dose5. Two weeks after thrombus aspiration, the CT showed hemorrhage absorption. The patient was discharged from the hospital, but he was still taking aspirin, clopidogrel, and atorvastatin. The patient's NIHSS score was 8 during discharge. Three months after the dual-antiplatelet treatment(triple dose of clopidogrel), the patient was switched to a single-antiplatelet treatment. After 6 months of follow-up, the patient's NIHSS score was 3, and the patient’s modified Rankin scale (mRS) score was 1. In addition, there was no stent restenosis in the CT angiography at the 6-month follow-up (Figure 6).