carotid endarterectomy

After 1967, Yasargil created an extracranial-cranial anastomosis for the treatment of cerebral ischemic disease. It has been popular for more than ten years, and the anastomotic approach has emerged in an endless stream, which is believed to prevent the development of transient cerebral ischemia and become a complete stroke. It can improve the loss of nerve function caused by ischemic cerebral infarction. Treatment of diseases: cerebral ischemic diseases Indication Carotid endarterectomy is available for: 1. There is a transient ischemic attack (TIA) symptom of the unilateral carotid artery system. Carotid angiography shows severe stenosis of the ipsilateral internal carotid artery (stenosis exceeds 50% of the original diameter, or residual diameter) Those with an inner diameter <2mm). 2. There is a symptom of TIA in the unilateral carotid artery system. Carotid angiography shows severe bilateral stenosis of the internal carotid artery. At least the carotid endarterectomy should be performed on the symptomatic side. The contralateral carotid endarterectomy should be performed after 4 weeks or no longer. 3. There is a symptom of TIA in the unilateral carotid artery system. Cerebral angiography shows severe stenosis of the ipsilateral internal carotid artery. The contralateral internal carotid artery is occluded. The surgical indication is the same as the unilateral internal carotid artery stenosis. Endometrial ablation. However, cerebral ischemia is easily caused by blocking carotid blood flow during surgery, and about 25% of patients need to use a shunt. 4. There is a symptom of TIA in the unilateral carotid artery system. Although the ipsilateral internal carotid artery stenosis is not serious, there is atherosclerotic plaque or ulceration. It is estimated that these lesions may be TIA or transient amaurosis. The cause of fugax), endometrial resection can prevent its recurrence. 5. There are symptoms of TIA in the vertebral-basal artery system, and carotid stenosis. The cerebral angiography shows that the posterior cerebral artery or more vertebral-basal artery arteries are supplied by the narrow internal carotid artery. Carotid endarterectomy It may improve the blood supply to the vertebral-basal artery and reduce the onset of TIA. 6. With or without TIA symptoms, but the usual vascular murmur suddenly disappeared, carotid angiography showed severe internal carotid artery stenosis, or thrombosis caused by complete occlusion, emergency carotid endarterectomy. 7. Asymptomatic severe internal carotid artery stenosis, or only vascular murmur, is the relative indication of endometrial ablation. Vascular murmurs indicate that arterial stenosis is more pronounced. Such patients have a greater risk of complete stroke and may consider prophylactic endometrial ablation. 8. Asymptomatic severe internal carotid artery stenosis, due to other diseases will undergo major surgery, in order to prevent cerebral ischemia or cerebral infarction due to blood pressure reduction during surgery, preventive carotid endarterectomy is feasible. Contraindications 1. Due to the occlusion of the internal carotid artery, the acute phase of cerebral infarction, endovascular revascularization may aggravate cerebral edema, and may turn the ischemic infarction into hemorrhagic infarction. 2. Chronic internal carotid artery occlusion, endometrial resection rate and long-term patency rate is very low. 3. There are serious systemic diseases that cannot tolerate the operator. Preoperative preparation These patients often have serious risk factors, especially cardiovascular diseases such as hypertension, coronary heart disease, myocardial infarction, heart failure, peripheral vascular disease, diabetes and lung disease. Therefore, the preparation of heart and lung function monitoring should be done before surgery. Surgical procedure Anesthesia and position general anesthesia. PaCO2 was maintained at a high level (4.7 to 5.3 kPa) during surgery. The EEG electrode is fixed to the scalp, and the electrode for ECG monitoring is placed on the chest to monitor the central venous pressure. If there is no contraindication to the heart, the systolic blood pressure is increased to 23 kPa (170 mmHg) when blocking carotid blood flow. The patient's position is supine, the head is biased to the opposite side, and the shoulder is raised to stretch the neck. Surgical procedure Incision It can be made oblique or transverse. The bifurcation of the common carotid artery and the external carotid artery is usually located 2 to 3 cm below the mandibular angle, but there are anatomical differences, which can be viewed on the carotid angiogram as a reference for the incision. Oblique incisions or "S" shaped incisions are well exposed, but the scars are larger after healing. The following mandibular plane is the midpoint, and the skin is cut along the anterior border of the sternocleidomastoid at 2 cm posterior to avoid injury to the mandibular branch of the facial nerve. However, the upper end of the incision may cut off the large ear nerves and leave the numb area of the ear. After the transverse incision healed, the scar was consistent with the skin pattern, which was more beautiful, but it was not as good as the oblique incision. The incision should be placed at the two horizontal fingers below the mandibular angle to avoid injury to the mandibular branch of the facial nerve. 2. Reveal the carotid artery After the skin is opened, the platysma is separated along the anterior border of the sternocleidomastoid muscle, and the anterior cervical nerve needs to be cut off. The sternocleidomastoid muscle is pulled to the outside, and the total facial vein is separated from the internal jugular vein and ligated and cut. There is a set of lymph nodes at the angle between the common vein and the internal jugular vein. If the operation is obstructed, it can be removed. The lower part is the carotid artery. When looking for the carotid artery, the finger movement of the finger is often used to guide the artery. However, in patients with carotid endarterectomy, this action should be extremely light, otherwise it can cause plaque or emboli in the lumen to cause cerebral embolism. On the inner side of the internal jugular vein is the carotid artery. The proximal segment of the common carotid artery is first separated, the arterial sheath is cut, the artery is separated from the surrounding tissue, and a thin strip is used to bypass the artery and a rubber tube is inserted to tighten the strip to control blood flow when the intima is removed. At this time, be careful not to hurt the adjacent vagus nerve. The distal side is separated until the bifurcation of the common carotid artery is revealed. Here, the external carotid artery is on the medial side, and the internal carotid artery is on the outside. The external carotid artery was first separated at least 2 cm, and the superior thyroid artery was separated from the inside. The fine band is also bypassed on the external carotid artery. The superior thyroid artery is very thin and can be controlled with only a temporary arterial clamp. When separating the internal carotid artery, it should be separated from the far side. The hypoglossal nerve is pulled inward and upward. The internal carotid artery is isolated on the lateral side of the hypoglossal nerve and its descending and internal jugular vein. The distal segment of the internal carotid artery should be separated at least 1 cm above the distal end of the arteriosclerotic plaque. The normal arteries are blue in color and soft in the wall; the plaques are yellow and hard. Separation of the lesion must be very gentle. The thin strip is bypassed in the normal part of the distal part of the internal carotid artery to control blood flow. 3. Determination of blood supply to the brain To determine whether the blood supply to the brain is sufficient when blocking blood flow, to determine whether the shunt should be placed to prevent cerebral ischemia. There are various methods: 1 blocking the blood flow of the common carotid artery and external carotid artery, and measuring the distal side of the internal carotid artery. The residual blood pressure, such as the mean arterial pressure is less than 50 ~ 60mmHg, that is, the shunt should be placed. 2 partial cerebral blood flow measurement (rCBF). Partial cerebral blood flow was measured after blocking blood flow. The normal rCBF was 50±10ml/(100g·min). If the blood flow was reduced to 20ml/(100·min), the shunt should be placed. It is cumbersome and expensive, and it cannot be continuously measured, so it is not commonly used. 3 EEG continuous tracing, rCBF fell below 20ml / (100g · min), EEG is significantly abnormal. This method is simple and non-invasive, can be continuously traced, but can not be quantified, and is not very reliable due to many factors such as anesthesia, PaCO2 level and the like. 4 Somatosensory evoked potential (SEP), which can reflect the level of cerebral blood perfusion, and the central conduction time (CCT) is prolonged during ischemia. The above methods should be comprehensively analyzed, and even within the tolerable range, there are still very few patients with cerebral ischemia. Generally, about 9% of the shunts need to be placed. 4. Place the shunt Before placement, heparin was injected with 5000 U, and the thin strips on the common carotid artery, external carotid artery and internal carotid artery were tightened, and the total neck and internal carotid artery wall were cut. The incision must exceed both ends of the plaque. Insert the distal end of the shunt tube (length 9cm, inner diameter > 3mm silicone tube) into the internal carotid artery, loosen the control band, and then quickly insert the shunt into the lumen of the vessel, then tighten the strap and tie the shunt to the artery. Inside the chamber, at this point the blood flows back from the shunt tube, rushing out of the debris that may be present and filling the lumen. The proximal end was inserted into the common carotid artery in the same manner, and the blood flow was injected into the internal carotid artery from the common carotid artery through a shunt. 5. Arterial plaque endarterectomy If the shunt tube is not needed, the artery wall can be cut, and the length of the incision should exceed the proximal and distal ends of the plaque. After the artery wall was cut, a yellow plaque was seen, and there was an interface with the muscle wall of the artery wall, which was separated by a small stripper. Start with the common carotid artery, separate from the internal carotid artery, cut off the proximal segment of the plaque and gradually separate it distally, and remove the plaque at the opening of the external carotid artery until the distal end of the plaque. Separation into the normal endometrium often adheres tightly to the muscular layer and cuts it off. After the endometrial ablation is completed, the lumen is flushed with heparin saline to prepare for suturing. 6. Suture the arterial wall The arterial wall incision was sutured with a 6-0 suture and sutured continuously from the distal side to the proximal side. When suturing to the last two needles, do not suture temporarily. First release the control band on the internal carotid artery, so that the reflux blood will rush out the air and possible blood clots and fragments, tighten the control band, and release the common carotid artery. The control belt rushes out of the air and blood clots, then tightens and quickly sews the last two stitches. If the shunt tube has been placed, it is sutured from both ends of the slit. When the last 3 to 4 needles are taken, the distal end of the shunt tube in the internal carotid artery is firstly tightened, and the proximal end of the common carotid artery is taken out. The control band is immediately tightened, and then the suture is quickly sutured and sewn to the last needle. Air and debris are discharged as described above. After the arterial wall is sutured, the control band of the external carotid artery is loosened, and then the control band on the common carotid artery is released, so that the blood can rush the possible air and debris into the external carotid artery, and finally the neck is released. The control zone on the artery restores blood supply to the brain. After surgery, it is generally not necessary to use heparin to neutralize heparin, because thrombus is easily formed within a few hours after surgery; but if hemostasis is difficult, heparin is required to neutralize heparin. 7. Arterioplasty (aterioplasty) Suture of the arterial wall after endarterectomy may cause arterial stenosis. A patch cut with a large saphenous vein can be used to fill the incision to enlarge the lumen. The patch was cut into a fusiform shape with a width of about 6 to 8 mm at the widest point, and was sutured continuously in the incision of the artery wall with a 6-0 nylon thread. 8. Suture incision Due to the use of heparin, hemostasis should be stopped before suturing and drainage should be placed. complication 1. Cerebral ischemic attack, which can be manifested as TIA or complete stroke. 2. Local hematoma, caused by anticoagulation and antiplatelet therapy, occurs mostly in obese patients with hypertension. Hematoma can be formed by incomplete or no drainage during surgery. If the amount of hematoma is large, the incision should be opened immediately to remove the hematoma. 3. Incision infection. 4. Mumps, carotid aneurysm formation, nerve damage, etc.