POMTEVAR trial is a multicenter, open-label and prospective random controlled study. Approximately 158 patients will be randomly allocated to thoracic endovascular repair (TEVAR) alone group or TEVAR plus methylprednisolone group and managed with respective treatment strategies. All study patients will be followed up in the outpatient clinic and undergo CT scans after 3 months from randomization. The primary objective is to test the hypothesis that PIS is lower in TEVAR plus methylprednisolone group than that in TEVAR alone group. The secondary objective is to test the hypothesis that changes of postoperative inflammatory indicators, incidence of postoperative acute renal failure and postoperative delirium, postoperative pain score are lower in TEVAR plus methylprednisolone group than that in TEVAR alone. In addition, 3-month all-cause death, 3-month major adverse cardiovascular events, 3-month aorta-related adverse events and 3-month aortic remodeling are compared between groups.

POMTEVAR trial is a multicenter, open-label and prospective random controlled study. Approximately 158 patients will be randomly allocated to thoracic endovascular repair (TEVAR) alone group or TEVAR plus methylprednisolone group and managed with respective treatment strategies. All study patients will be followed up in the outpatient clinic and undergo CT scans after 3 months from randomization.

The primary objective is to test the hypothesis that PIS is lower in TEVAR plus methylprednisolone group than that in TEVAR alone group. The secondary objective is to test the hypothesis that changes of postoperative inflammatory indicators, incidence of postoperative acute renal failure and postoperative delirium, postoperative pain score are lower in TEVAR plus methylprednisolone group than that in TEVAR alone. In addition, 3-month all-cause death, 3-month major adverse cardiovascular events, 3-month aorta-related adverse events and 3-month aortic remodeling are compared between groups.

TEVAR plus glucocorticoids group: Patients receive a single preoperative dose of 500 mg of methylprednisolone diluted in 250 mL of physiological saline 2 hours before TEVAR as a 30-minute infusion.

TEVAR alone group: Patients receive a single preoperative dose of 250 mL of physiological saline 2 hours before TEVAR as a 30-minute infusion.

TEVAR steps:According to the preoperative imaging, the potential risk location of the aortic dissection or rupture and the extent of lesion involvement are evaluated, and the appropriate anchoring zone is selected to ensure a sufficient anchorage area of more than 15 mm. If the distance between the potential accident site and the left subclavian artery (LSA) is less than 15 mm, LSA will be covered to obtain sufficient anchoring area. LSA revascularization will be performed by chimney technique or hybrid operation, depending on the choice of the surgeon. The left femoral artery is punctured or cut, the 5F artery sheath is inserted, and the pigtail catheter is inserted into the ascending aorta along the sheath. Next, the aortic covered stent was implanted reverse through the femoral artery under the guidance of the wire. When the stent was released, rapid pacing or intravenous antihypertensive drugs was used to ensure that the blood pressure was lower than 90 mmHg. After stent implantation, re-angiography to confirm the stent location and blood flow, which will indicate whether the operation was successful or not. After all above, the patients will be observed in hospital for at least 3 days. Controls of the blood pressure and heart rate and relief of the symptoms will meet the discharge criteria.

Inclusion Criteria:

1. Age >18 years;
2. Be confirmed as Stanford type B aortic dissection by aorta computed tomography;
3. From onset to first clinical attach <90 days;
4. The subject or legal guardian understands the nature of the study and agrees to its provisions on a written informed consent form;
5. Availability for the appropriate follow-up visits during the follow-up period;
6. Capability to follow all study requirements.

Exclusion Criteria:

1. Laboratory examination in the last 3 months suggested severe renal dysfunction (serum creatinine >176.8umol/L or estimated creatinine clearance eGFR <30ml/min;
2. Laboratory examination in the last 3 months suggested severe liver dysfunction (ALT> 2x Max or TBIL> 2x Max);
3. Diabetics with poor glycemic control: fasting blood glucose ≥13.9mmol/L or hBA1c ≥8.5%;
4. Severe hypokalemia (Serum potassium ion concentration was less than 2.5mmol/L);
5. HIV positive, hepatitis B or C positive;
6. Immune inflammatory diseases (except skin and respiratory diseases that can be treated locally);
7. Glaucoma;
8. Gastric or duodenal ulcer;
9. Active infection (persisting body temperature >38℃; etiological evidence or imaging evidence);
10. On immunosuppressive therapy;
11. Patients with malignant tumor whose life expectancy is less than 1 year;
12. Genetic diseases, including Turner syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Loeys-Dietz syndrome and other connective tissue diseases;
13. Rheumatic immune diseases, including multiple arteritis, giant cell arteritis, polyarteritis nodosum, etc;
14. Pregnant women;
15. Severe mental illness;
16. Poor compliance, difficult to cooperate with follow-up;
17. Participate in another investigationdrug or medical device study or another investigationstudy of an approved drug or medical device within 30 days prior to the first visit of the current study;
18. Any conditions or laboratory findings that the investigator considers inappropriate for inclusion.