1.Brief history: Female, 52 years old, visited the gynecology department because of “incomplete menstruation”, and during hospitalization, chest X-ray indicated dilatation of the thoracic aorta, and CTA indicated thoracic aortic aneurysm, so she was transferred to the vascular surgery department. During the course of the disease, there was no chest pain, chest tightness and other discomfort, and there was a history of hypertension for many years. The patient was a middle-aged female, and the examination suggested aneurysmal dilatation of the beginning of the descending aorta and involvement of the left subclavian artery, with the proximal end of the aneurysm about 1 cm from the left common carotid artery, and the maximum diameter of the aneurysm was measured to be about 6.5 cm. Due to the short neck of the aneurysm, it was not possible to perform conventional endoluminal repair with a simple overlapping stent. The patient was found to have a high degree of atrioventricular block on routine preoperative examination, and a pacemaker was implanted with the assistance of a cardiology consultation, followed by surgery. During the operation, a 6-mm diameter ePTFE artificial vessel was taken under endotracheal anesthesia to perform a right common carotid artery-left common carotid artery bypass, followed by endoluminal repair of the thoracic aortic aneurysm. Intraoperative imaging showed a pseudoaneurysm in the aortic isthmus with a diameter of 6 cm and a length of about 8 cm, the aneurysm was biased to the left, the left subclavian artery was pushed upward to the left, the left vertebral artery was poorly visualized, and the right vertebral artery was thickened. A 30-mm diameter overlapping stent was placed near the left edge of the cephalic trunk to cover the aortic arch and descending aorta. The final angiogram showed good stent morphology, patency of the carotid-cervical bypass, and no obvious II endoleak caused by left subclavian artery regurgitation. After postoperative treatment with symptomatic management, recovery was good. 4. Case review: The difficulty of this case is that the tumor has involved the beginning of the left subclavian artery and the proximal end of the tumor is about 1 cm away from the left common carotid artery, so we mainly focused on the following points during the treatment: (1) The choice of surgical approach. The traditional open surgical treatment can be chosen in this case, but open surgery has disadvantages such as large trauma and many complications. Preoperatively, after careful measurement, it was possible to obtain a proximal anchorage zone of sufficient length by closing the left common carotid artery, so we decided to use hybrid surgical treatment. (2) Extension of the proximal anchorage zone and prevention of endoleaks. Since the aneurysm had involved the beginning of the left subclavian artery, and the proximal end of the aneurysm was less than 1 cm away from the left common carotid artery, and the angiography suggested that the proximal end of the aneurysm was about 2 cm away from the cephalic trunk, we considered performing a right common carotid artery-left common carotid artery-left vertebral artery bypass and proximal ligation of the left subclavian artery to extend the proximal anchorage zone and avoid the occurrence of II endoleak. (3) Intraoperatively, it was found that due to the pushing of the aneurysm, the left subclavian artery could not be free at the posterior side of the proximal left clavicle. Considering that the angiography suggested that the left vertebral artery was not clearly visualized and the right vertebral artery was the dominant artery, it was decided that the left subclavian artery bypass would not be performed temporarily, and the decision to perform proximal embolization of the left subclavian artery and bypass surgery would be made after surgery according to the presence or absence of endoleaks and symptoms of vertebral artery steal. In this case, no endoleaks or obvious symptoms of vertebral artery theft were found in the postoperative follow-up, so no further surgical treatment was performed.