2.1 Clinical data
2.1.1 Patient selection
Clinical data was collected from 53 patients with symptomatic carotid artery dissection between January 2013 and June 2018 at the Second Affiliated Hospital of Chongqing Medical University, Xinqiao Hospital Affiliated to Army Medical University, Chongqing Three Gorges Central Hospital, and Chongqing Fifth People's Hospital. Among them, 41 were male and 12 were female. The ratio of males to females was 3.42:1, and the ages ranged from 19 to 67 years. The average age of the operation group was 50.96 ± 8.3 years whereas the average age of the non-operation group was (48.8 ± 12.3) years. All the patients underwent blood biochemical tests. As a result, some patients underwent autoimmune related tests and thyroid function-related examinations. All the patients underwent whole brain digital subtraction angiography before surgery, and some patients performed high-resolution magnetic resonance imaging, computed tomography angiography (CTA), or cervical vascular ultrasound. Carotid artery dissection was diagnosed by cerebral angiography, and the location and nature of the lesion were analyzed. Among the 53 patients who participated in the study, 45 had a single extracranial internal carotid artery dissection, four had bilateral extracranial internal carotid artery dissection, one had intracranial artery dissection, one had middle cerebral artery dissection, and three had vertebral artery dissection. The main manifestations of the lesions were post-dissection stenosis in 50 cases and dissecting aneurysm in three cases. Among them, 24 patients received antithrombotic therapy as decided by the treating physician and could either include anti-platelet therapy or anticoagulation using warfarin with an INR goal of 2–3. but the effect was poor (invalid condition or progress). Endovascular stent angioplasty was performed on the operation group and 29 patients only received anti-platelet therapy or anticoagulation treatment for the non-operation group. The MRS scores of surgical and non-surgical patients were recorded after three months.
2.1.2 Inclusion criteria
a) Symptomatic carotid artery dissection with lumen stenosis or aneurysm formation (NIH Stroke Scale score (> 1 point) confirmed by cerebral angiography (DSA); b) Invalid drug treatment, continued progression of the disease, or imaging examination indicated aggravation of the lesion (the control group did not undergo surgical treatment as a non-parallel control group).
2.1.3 Exclusion criteria:
a) Sensitivity to contrast media; b) Intolerance to dual antiplatelet drugs (aspirin and clopidogrel); c) Hematological diseases or severe bleeding tendency; d) Active bleeding three weeks before the operation e) Obvious tortuosity or ripple of diseased vessels leading to difficulty in operation; f) Severe cardiac, pulmonary, and renal diseases; g) Concurrent with other vascular dissections.
2.2 Method
2.2.1 Antithrombotic regimen
Patients received dual antiplatelet therapy (aspirin 100 mg and clopidogrel 75 mg) daily for at least 5 days. Patients who could not receive dual antiplatelet therapy for that period were loaded with oral aspirin 300 mg and clopidogrel 300 mg on the day of the procedure. Dual antiplatelet therapy was continued for at least 3 months after the procedure beyond which only a single antiplatelet agent (aspirin 100 mg or clopidogrel 75 mg daily) was continued.
2.2.2 Surgical treatment
Procedures were performed with patients under monitored anaesthesia care. Intravenous heparin was given during the procedure to maintain an activated clotting time between 250 and 300s. A trans-femoral arterial approach was used, and an 8 French sheath was positioned in the common carotid artery. Microcatheter access distal to the lesion was obtained in all cases and angiography was performed to confirm intraluminal position. The use of distal embolic protection was operator dependent and was used when the severity of the stenosis did not preclude passage of the protection device, part of patients was not placed due to the location of the lesion is located in the Carotid siphon or higher. Pre-stent angioplasty was done in selected cases when it was deemed necessary to improve lumen diameter for the safe passage of the stent delivery system. Stent implantation was performed per standard protocols.
2.2.3 Image analysis
All images (CTA/MRA/DSA) were reviewed. The DSA images were analyzed to record the characteristics of the dissected vessel for the location, degree of stenosis (defined by the NASCET Criteria), type of stenosis (smooth or irregular), presence or absence of intimal flap, false lumen, presence of thrombus and/or distal emboli and presence and characteristics of dissecting aneurysm[6-8].
2.2.4 Postoperative management
Post the operation, ECG, blood oxygen, and blood pressure were monitored for two days to observe the pulsation of the lower limb artery[9-12]. The blood pressure was controlled by urapidil or nicardipine for three days after operation and was 20-30% lower than the baseline blood pressure. Further, the related symptoms of nervous system were observed. The occurrence of any recurrent stroke, TIA, cardiovascular event, or death was recorded.
2.2.5 Follow-up time
The average follow-up time was 21.8 months in the operation group and 17.5 months in the non-operation group. The second average follow-up time was 34.2 months and 25 months in the non-operation group[6,8,11].
2.2.6 Clinical outcome analysis
The preoperative and postoperative mRS scores, long-term follow-up mRS scores, and recurrence rates of stroke (ischemic or hemorrhagic) were recorded in the operation and non-operation groups. The perioperative complications and the success rate of the operation were counted. According to the NIHSS score at admission, the patients were divided into < 4 points, > 4 points, and < 10 points subgroups respectively.
2.2.7 Statistical analysis
SPSS20.0 software (IBM Corp, Armonk, NY, USA) was used for statistical analysis. The measurement data were expressed as mean±sd, and the comparison between groups was performed by a one-way analysis of variance. P<0.05 was set for statistically significant.