2.1 Research content
2.1.1Research objects and sources
patients with carotid stenosis who underwent carotid endarterectomy in the Department of Vascular Surgery, Second Affiliated Hospital of Nanchang University, from January 2013 to June 2017, and there are 89 patients with complete case data.
2.1.2 Inclusion criteria
(1) unilateral or bilateral carotid atherosclerotic stenosis;
(2) symptomatic carotid stenosis >50%;
(3) Asymptomatic carotid stenosis >70%;
(4) Subjects and their families volunteered and signed the informed consent form.
2.1.3Exclusion criteria
- intracranial hemorrhage within 3 months, fresh brain infarction within 2 weeks;
(2) uncontrollable hypertension;
(3)serious tendency to hemorrhage;
(4) complete occlusion of the diseased lateral carotid artery;
(5) intracranial aneurysm which can not be treated in advance or concurrently;
(6) carotid bifurcation position is high or the common arteries are narrow below the clavicle plane.
2.2 Research methods
2.2.1 Preoperative examination
(1)After admission, the patients’ blood pressure, pulse and body temperaturewas monitored according to the routinely nursing of vascular surgery.
(2)Improve the examination of blood routine, urine routine, stool routine, blood type, liver and kidney function, blood sugar, coagulation function, etc.,and rule out severe liver and kidney dysfunction and hemorrhagic disease with bleeding disorders.
(3)Preoperative chest X-ray examination and electrocardiogram examination excludes patients with severe cardiopulmonary disease.
(4)Preoperative examinations were performed such as carotid ultrasound, CT angiography or digital subtraction angiography, cranial magnetic resonance imaging, magnetic carotid plaque analysis, craniocerebral perfusion, etc., learn more about the location, extent of carotid stenosis and the charactor of carotid plaques, etc.
2.2.2 Preoperative preparation
(1)Understand the patient's medical history, confirm the diagnosis, and eliminate the surgical contraindications.
(2)Before operation examinate imaging datas of patients like carotid ultrasound, CTA and magnetic resonance , to determine the location and extent of carotid stenosis, stenosis, plaque stability, etc., to guide surgical treatment.
(3)Preoperative oral aspirin or Plavix antiplatelet therapy, oral statin to stabilize plaque, reduce blood lipid treatment, strict control of hypertension, diabetes, hyperlipidemia.
(4)Control risk factors, adjust blood sugar, control blood pressure; quit smoking before surgery, exercise deep breathing, improve breathing function, practice defecating in bed and so on.
(5)Preoperative blood preparation, cross-matching blood to prevent intraoperative bleeding.
(6) Cessation of oral aspirin treatment one day before surgery.
2.2.3 surgical methods
(1)All patients underwent valgus endarterectomy and intravenous anesthesia with endotracheal intubation. The patients were supine, the scapula was high, the head was biased to the opposite side of the surgery field, and a cricoid cushion is placed under the head. The front area of the neck is exposed.
(2)Made oblique vertical incision along the anterior border of the sternocleidomastoid muscle, and then cut the skin, subcutaneous and platysma muscles in proper order, and did longitudinally separation along the anterior border of the sternocleidomastoid muscle, and pull the sternocleidomastoid muscle to the outside. After the carotid sheath was exposed, opened the carotid sheath, and the common carotid artery, internal carotid artery and external carotid artery were exposed freely to avoid injury to the nearby vagus nerve and hypoglossal nerve. In the relatively normal position without hardened plaque, the superior thyroid artery, external carotid artery, internal carotid artery, common carotid artery were blocked respectively. 1% lidocaine closed the carotid sinus and peripheral nerves, after systemic venous heparinization (0.5~1.0mg/ml), made longitudinally incision of the common carotid artery and internal carotid artery wall, stripped carotid intima and plaque, carefully removed the plaque and endometrial tissue from the wall until the vessel wall was smooth and after the distal endometrium was trimmed, it was fixed by suture. The arterial wall was sutured continuously using 5-0 non-invasive vascular suture, and the occlusion forceps of the external carotid artery, common carotid artery, internal carotid artery and superior thyroid artery were sequentially opened.
(3)The blocking time was 20-36 minutes, with an average of 26 minutes. Only one case was treated with a diverter tube and a patch. None of the ramaining cases used drainage tube or patch suture. After the occlusion forceps were removed, 125 ml of mannitol was used to reduce intracranial pressure. Protamine was injected to deheparinized and the ACT index was monitored. The incision was sutured layer by layer after strict hemostasis, and draining tube was placed in the neck region to drainage . Surgical process is showen in the chart.
2.2.4 postoperative treatment
The patients were sent to the recovery room to wake up. After waking up, they were sent to the general ward or ICU for monitoring.They were given ECG and oxygen saturation monitoring, observed changes in patient consciousness, vital signs and wound drainage, strictly controlled blood pressure (100-130) / (70-90) mmHg, and use mannitol (125ml / time, twice a day for 3 days) to reduce intracranial pressure, postoperative aspirin combined with Plavix double antiplatelet therapy,parents were treated by oral Atto vastatin calcium tablets for hypolipidemic therapy and changed to oral aspirin antiplatelet therapy 6 months later.
2.2.5 Data collection
The clinical data of the subjects were retrospectively collected and collated; the general clinical data of the patients included age, gender, life history (whether smoking, drinking) combined with underlying diseases and risk factors (hypertension, diabetes, coronary atherosclerotic heart history, cerebral infarction, history of peripheral arterial disease). Before operation, CTA, craniocerebral MRI, carotid MRA and other examinations were preformed, improved mRS score was used 1 day before surgery;
Surgical treatment included intraoperative and perioperative complications; follow-up was performed through outpatient, inpatient, or telephone follow-up. Follow-up included complications, stroke, and symptom improvement and improved mRS score.
2.2.6 Determination of risk factors and complications
(1)Hypertension: systolic blood pressure is greater than or equal to 140mmHg and/or diastolic blood pressure is greater than or equal to 90mmHg,with previous history of hypertension and oral antihypertensive drugs.
(2)Diabetes: Symptoms of diabetes plus plasma glucose at any time is greater than or equal to 11.1 mmol/L, or FPG is greater than or equal to 7.0 mmol/L, or OGTT2h PG is greater than or equal to 11.1 mmol/L,with previous history of diabetes and treatment with insulin or oral hypoglycemic agents.
(3)Coronary atherosclerotic heart disease: coronary atherosclerosis causes stenosis or obstruction of the lumen, or (and) heart disease caused by myocardial ischemia or necrosis due to functional changes in the coronary artery (spasm), referred as Coronary heart disease, including acute coronary syndrome and chronic coronary disease.
(4)TIA: transient cerebral ischemic attack, including transient amaurosis, vision loss, visual field defect, or transient vertigo, unstable standing and other symptoms.
(5)Modified mRS score(Table 1) [10].
(6) Judgment of carotid stenosis: according to the North American Society of Carotid Surgery (NASCET) criteria [4]: mild (0-29%), moderate (30-69%), severe ( 70-99%). The calculation formula for the degree of stenosis:(1 - the narrowest diameter of the carotid artery / the diameter of the normal internal carotid artery at the distal end of the stenosis lesion) x 100%.
(7) Symptomatic carotid stenosis: A transient or persistent function defect of ipsilateral cerebral hemisphere or retina associated with stenotic vessel has occurred in the past 6 months. Symptoms include: numbness and weakness in the body and face, dysarthria, aphasia, visual field defect, and transient amaurosis.
(8)Hyperperfusion syndrome [11] is defined as beating pain in the forehead, ankle and eye socket with or without nausea and vomiting, orimaging failure to indicate unilateral focal seizure of cerebral infractionor focal nerve function defect.
(9)Follow-up endpoints: major cardiovascular and cerebrovascular events such as death, stroke or myocardial infarction.
(10)Judgment of cranial nerve injury: Cranial nerve injury was defined as 8, 9, 10, 11, 12 and sympathetic nerve injury. Mandibular branch paralysis often leads to distortion of commissure defined as facial nerve branch injury. Glossopharyngeal disorders are defined as uvula deviation and dysphagia. Assessment of damage of vagus nerve and its branch includes dysphagia, hoarseness, vocal cord paralysis, etc. accessorius injuries include sternocleidomastoid and trapezius muscle defects. Sublingual nerve injury is characterized by a shift of the tongue to one side.
- 3 statistical analysis
Statistical analysis was performed using SPSS23.0 statistical analysis software. The measurement data were expressed by mean and standard deviation (X±S), and the count data was expressed by the number of cases and percentage; the measurement data of non-normal distribution was measured by Wilcoxon rank sum test. Comparisons of counting data were made using chi-square test; survival analysis was performed with Kaplan-Meier method, and Cox proportional hazard regression model was used for multivariate analysis. Statistical significance was expressed as p< 0.05.
Table 1
score | Description |
0 | Completely asymptomatic |
1 | Despite symptoms, it has no obvious dysfunction and can complete all daily work and life. |
2 | Mild disability, unable to complete all pre-illness activities, but do not need help to take care of their daily affairs |
3 | Moderate disability, need some help, but can walk independently |
4 | Moderately and severely disabled, unable to walk independently, need help in daily life |
5 | Severe disability, bedridden, incontinence, complete dependence on others in daily life |
6 | Dead |