The goal of this prospective, multicenter, randomized controlled clinical trial is to evaluate the safety and efficacy of the WeFlow-EndoSeal™ vAorta Vascular Plug System combined with thoracic endovascular aortic repair (TEVAR) in patients diagnosed with Stanford type B aortic dissection. The main questions it aims to answer are:

Does WeFlow-EndoSeal™ combined with TEVAR provide superior therapeutic efficacy versus standard TEVAR alone for Stanford type B aortic dissection? Does the combined intervention maintain a comparable safety profile relative to standard TEVAR alone? Researchers will compare the test arm (WeFlow-EndoSeal™ Aorta Vascular Plug System plus TEVAR) with the control arm (standard TEVAR alone), with subjects randomized at a 1:1 ratio, to see if the add-on device enhances treatment outcomes without elevating safety risks.

Participants will:

Be randomly assigned to either the test arm or the control arm with equal probability, free from subjective influence of investigators or participants Undergo the corresponding standardized endovascular procedure per their group allocation Complete protocol-specified clinical follow-ups and imaging assessments for efficacy and safety evaluation

Inclusion Criteria:

1. Patients aged 18 to 80 years old.
2. Patients are diagnosed with subacute or chronic Stanford Type B aortic dissection and are scheduled to undergo TEVAR.
3. Upon imaging evaluation, The the maximum diameter of the false lumen landing zone where the vascular plug is intended to be deployed shall be in the descending thoracic aorta is ≤ ■■ mm..
4. Patients have suitable access conditions evaluated by imaging, allowing the steerable catheter delivery systems to enter the false lumen via the iliac artery, infrarenal aorta, or at the level of the renal artery tear.
5. Patients are able to understand the purpose of the trial, participate in this study voluntarily, has signed the informed consent form personally or via their legal representative, and is willing to complete follow-up in accordance with the protocol requirements.

Exclusion Criteria:

1. Presence of persistent malperfusion of visceral arterial branches caused by dissection.
2. ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■.
3. Infectious aortic disease, Takayasu's arteritis, Marfan syndrome (or other connective tissue diseases).
4. Acute systemic infection.
5. History of myocardial infarction, TIA, or stroke within the past 3 months.
6. NYHA Class IV cardiac dysfunction (see Appendix 1 of the protocol) or LVEF < 30%.
7. Hematologic abnormalities, defined as: leukopenia (WBC < 3×10⁹/L), anemia (Hb < 90 g/L); coagulopathy, thrombocytopenia (PLT count < 50×10⁹/L).
8. Renal insufficiency with serum creatinine > 221 μmol/L (or 2.5 mg/dL) and/or end-stage renal disease requiring renal dialysis, as determined by the investigator after comprehensive assessment.
9. Severe hepatic insufficiency: alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 5× upper limit of normal; serum total bilirubin (STB) > 2× upper limit of normal.
10. Hypersensitivity to contrast media, materials of the Aorta Vascular Plug, or the delivery system.
11. Female subjects who are pregnant or breastfeeding.
12. Concurrent participation in another clinical trial of drugs or devices.
13. Patients with a life expectancy of less than 12 months (e.g., advanced malignant tumor).
14. Any other medical conditions or abnormalities that, in the investigator's opinion, render the subject ineligible for this study.

Intraoperative Angiography Exclusion Criteria

After completion of the stent-graft procedure (including implantation of stents for the proximal and/or distal tears as necessary), DSA angiography revealed:

1. Presence of other vascular lesions (e.g., coronary, renal, mesenteric arteries, etc.) requiring intervention, resulting in an impact on the postoperative medical regimen.
2. Proximal Type I endoleak or Type III endoleak.
3. Presence of a tear in the descending aorta above the upper margin of the celiac trunk ostium.