Carotid body aneurysm: It is a chemoreceptor tumor that grows at the bifurcation of carotid artery, immediately adjacent to or encircling the carotid artery. Due to the special location of these tumors, the anatomy of the lesion is complex and the tumor is rich in blood flow. Therefore, carotid body aneurysm resection is sometimes difficult. The surgery may damage the nerves, and sometimes the carotid artery block or carotid atherectomy reconstruction to control massive bleeding may also cause insufficient blood supply to the brain, resulting in hemiparesis or death is not uncommon. The etiology of the disease is unknown, but two types are found clinically: 1. familial type, which accounts for about 6.5% of the total number of cases and is mostly bilateral. 2. 2. The epidemic type, which is mostly unilateral in onset. This disease is mostly benign, but there are a few malignant changes, and malignant tumors account for about 5-9%. Shamblin classifies carotid body aneurysms into 3 grades: Grade I: the aneurysm is confined to the bifurcation of carotid artery and has no adhesion with the wall of internal and external carotid artery; Grade II: the aneurysm extends below the bifurcation of carotid artery, partially wraps the vessels at the bifurcation of carotid artery and adheres to the wall of internal and external carotid artery; Grade III: the aneurysm completely wraps the bifurcation of carotid artery and the carotid artery above and below it and adheres closely to the carotid artery. Therefore, it is necessary to clarify the grading of the tumor and its relationship with the carotid artery and surrounding tissues before surgery. Carotid body aneurysms are less common, but not uncommon. A neck mass is often misdiagnosed as an enlarged lymph node, with a clinical misdiagnosis rate of up to 36.9% being reported. Although Fontaine’s sign can help diagnose the disease, clinical diagnosis is mainly based on imaging methods, such as ultrasound, DSA, CT, and MRI. doppler ultrasound can detect the neck mass and its blood supply status, and understand the relationship between the mass and the carotid artery, which is helpful for diagnosis. dsa carotid angiography It can not only observe the changes of carotid artery, discover the tumor, determine the blood supply status of the tumor and clarify the relationship between the location of the tumor and carotid artery, but also observe the traffic condition of the arteries between the two sides of the brain. Carotid CT scan can understand the size of carotid body aneurysm, the scope of influence and the relationship between the tumor and the surrounding tissue structure. Spiral CT three-dimensional imaging technology can even clearly show the three-dimensional image of carotid body aneurysm, carotid artery and its branches, which is very valuable for determining the diagnosis and making surgical plan. The only effective treatment for carotid body aneurysm is surgical resection. The surgical options are aneurysm resection, partial resection of the aneurysm and carotid artery, anastomosis or bridging of the common carotid artery of the internal carotid artery, and aneurysm + external carotid artery resection. Carotid body aneurysm resection is indicated for most patients. In cases of Shamblin type III or large carotid aneurysms where the bifurcation of the carotid artery must be removed at the same time, an end-to-side anastomosis between the common carotid artery and the internal carotid artery should be performed first with an autologous saphenous vein or PTFE artificial vessel to ensure the blood supply to the brain. Adequate preoperative preparation is necessary. Preoperative, intraoperative and postoperative attention should be paid to: 1. Adequate knowledge of the disease should be gained, and surgery should be performed only after a clear diagnosis and adequate preoperative and psychological preparation, otherwise the surgery is often terminated midway, causing difficulties for further treatment. 2.Surgical operation should be gentle and avoid squeezing the tumor, because some tumors have endocrine function. 3.Patience and care should be taken when ligating the arterial branches supplying blood to the tumor to reduce bleeding and avoid damaging the carotid artery wall. 4.Arterial diversion tubes should be prepared to prevent cerebral ischemia during the arterial reconstruction. 5. The patient’s consciousness, physical activity and hoarseness should be closely observed after surgery, and further treatment should be given if necessary.