Safety and Efficacy of TEVAR Combined with Long Bare-metal Stents in the Intervention of ATBAD (SAFE-COVER)

Safety and Efficacy of TEVAR Combined with Long Bare-metal Stents in the Intervention of ATBAD: a Prospective and Cohort Study

The primary objective of this study is to evaluate the safety and efficacy of the TEVAR combined with extended bare-metal stenting (distal landing zone ≥2 cm below renal arteries) in patients with acute complicated type B aortic dissection (ATBAD).

Additionally, to prevent postoperative true lumen hypoperfusion in residual thoracoabdominal aortic dissection (visceral zone, infrarenal aorta, and iliac arteries) and persistent ischemic manifestations in visceral and lower extremity arteries post-endovascular repair, extended bare-metal stents are deployed to maintain adequate distal true lumen patency. This strategy ensures perfusion to visceral branches and lower limbs while preparing for future complete endovascular aortic repair.

Study Overview

• Status: Not yet recruiting
• Conditions: Aortic Dissection Type B
• Intervention / Treatment: Device: Hybrid TEVAR combined with long bare-metal stent intervention

Detailed Description

Stanford type B aortic dissection (TBAD) accounts for 25-40% of all aortic dissections, characterized by acute onset, rapid progression, and high mortality, representing a critical cardiovascular emergency. While thoracic endovascular aortic repair (TEVAR) remains the standard intervention for TBAD, its benefits on true lumen remodeling and false lumen thrombosis are primarily limited to the stent-graft covered segment. Distal to the stent-graft, persistent re-entry tears in thoracoabdominal arteries convert preoperative exit sites into new entry points. Although TEVAR improves true lumen perfusion distal to the stent-graft, remodeling efficacy remains suboptimal, particularly in cases with preoperative true lumen collapse where post-TEVAR true lumen dimensions remain critically compressed by large false lumen volumes. Currently deployed stent-grafts typically measure 15-20 cm in length. Conventional TEVAR requires ≥1.5 cm proximal healthy aortic segment as landing zone to prevent retrograde type A dissection (RTAD) and ensure stability. For patients with inadequate proximal landing zones (<1.5 cm), advanced techniques including branched stent-grafts, fenestrations, and parallel grafting have enabled TEVAR implementation even with ≤0.5 cm landing zones, facilitated by evolving device technologies and operator expertise. The "TEVAR+bare-stent" hybrid approach theoretically enhances aortic remodeling through reduced radial force. However, standard TEVAR typically deploys single stent-grafts at the proximal descending aortic tear. Extended stent-graft coverage beyond celiac axis level risks visceral artery occlusion, making maintenance of distal organ and limb perfusion an enduring challenge. Moreover, residual distal thoracoabdominal dissection carries risks of false lumen aneurysmal degeneration and rupture, particularly >5 years post-TEVAR. Secondary interventions for chronic residual dissections are complicated by intimal calcification from prolonged false lumen hypertension, combined with chronic hypoxia and inflammation that compromise aortic wall integrity. Persistent false lumen expansion and rupture in residual thoracoabdominal dissection are observed in 23-35% of conventional TEVAR cases, particularly affecting young-to-middle-aged patients with suboptimal blood pressure control beyond 5-year follow-up. Technical challenges in secondary visceral branch reconstruction further compromise long-term quality of life. Therefore, post-endovascular true lumen remodeling in thoracoabdominal segments warrants particular attention, as aortic remodeling constitutes a crucial determinant of therapeutic success beyond procedural technique alone.

This study aims to validate the feasibility and safety of proximal stent-graft plus extended distal bare-metal stenting in thoracoabdominal aorta, compare its efficacy with conventional TEVAR, and characterize its impacts on aortic remodeling and subsequent visceral/distal arterial reconstruction. We anticipate this research will provide critical clinical evidence for managing residual thoracoabdominal dissection after acute TBAD repair.

Using imaging-based analysis and clinical follow-up, this study will compare: (1) conventional TEVAR vs. (2) hybrid proximal stent-graft + extended distal bare-stent strategies in terms of morphological remodeling, adverse events, and long-term outcomes. The findings may elucidate differential impacts on aortic reconstruction and visceral/iliac revascularization, offering evidence-based guidance for managing distal dissection in acute TBAD.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Xunqiang Prof. Liu, M.D.; Phone Number: +8613888390126; Email: liuxunqiang1001@163.com
• Study Contact Backup: Name: Zheng Dr. Jia, Ph.D.; Phone Number: +8613669776843; Email: jiazhenghappy@163.com

Study Locations

• China
  • Yunnan
    • Kunming, Yunnan, China, 650051
      • Yan'an Affiliated Hospital of Kunming Medical University
      • Contact: Zheng Dr. Jia, Ph.D.; Phone Number: +8613669776843; Email: jiazhenghappy@163.com
      • Contact: Xunqiang Prof. Liu, M.D.
      • Contact: Zheng Dr. Jia, Ph.D.
      • Contact: Ruhong Prof. Li, M.D.
      • Contact: Enshuai Dr. Zhu, M.S.
      • Contact: Huanjun Prof. Chen, M.S.
      • Contact: Ying Dr. Yanf
      • Contact: Min Dr. Ji, M.S.
      • Contact: Chunxin Dr. Yang, M.S.
      • Contact: Jinhui Dr. Zhang, M.D.
      • Contact: Lei Dr. Cong, M.S.
      • Contact: Jiaqi Dr. Li, M.S.
      • Contact: Yan Dr. Wei, M.S.
      • Contact: Liqiong Dr. Zhang

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• ≧18 years old, ≦80 years old;
• Acute phase with a course of disease ≦14 days;
• CTA confirmed diagnosis of active dissection type B in accordance with the Stanford classification in the ESC guidelines, and requiring TEVAR surgery;
• For patients with acute non-type A and non-type B aortic dissection involving the left subclavian artery: current technologies (such as fenestration, single branch, chimney, etc.) can be used to solve the reconstruction of the left subclavian artery;
• The distal end of the dissection exceeds the renal artery plane;
• Signed informed consent (emergency waiver applicable), with primary intervention using CTAG devices. Adjunctive procedures may include LSA revascularization, percutaneous fenestration, aortic/peripheral stenting, surgical fenestration, or bypass grafting.
• Medical record completeness >90% with mandatory CTA data;
• Protocol compliance including follow-up adherence

Exclusion Criteria:

• Dissection termination above renal arteries;
• Major aortic surgery within 30 days prior (except LSA revascularization);
• Iliofemoral stenosis/angulation precluding endovascular access;
• Non-diagnostic CTA image quality;
• Indeterminate symptom onset time;
• Traumatic TBAD, intramural hematoma, or penetrating aortic ulcer;
• Complete thoracic aortic thrombosis pre-TEVAR;
• Re-intervention within 12 months post-TEVAR for non-aortic indications;
• Renal failure: Baseline serum creatinine >2.5 mg/dL (high-risk for contrast nephropathy);
• Known device material hypersensitivity;
• Systemic infection increasing endograft infection risk;
• Evidence of aortic infection;
• Connective tissue disorders (e.g., Marfan syndrome);
• Bowel necrosis from visceral ischemia;
• Participation in other device/drug trials within 1 year;
• Moribund status: ASA class 5 with <24h life expectancy;
• Refractory shock (SBP <90 mmHg);
• Pregnancy or lactation;
• Active substance abuse.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Carstor® 70-240mm, AnkuraTMⅡ60-200mm, WeFlow-TbranchTM and Fabulous® Device Surgical Implant; Subjects with acute type B aortic dissection were treated with an endovascular procedure using the Carstor® 70-240mm, AnkuraTMⅡ60-200mm, WeFlow-TbranchTM 160-240mm Thoracic Aortic Endoprosthesis and the Fabulous® 45-150mm long big bare stent via femoral artery access. (Permanent implant)

Device: Hybrid TEVAR combined with long bare-metal stent intervention; - Primary TEVAR: Primary TEVAR: Employ Carstor® 70-240mm, AnkuraTMⅡ60-200mm, WeFlow-TbranchTM 160-240mm endograft deployed with ≥2cm proximal landing zone coverage. Concurrent bare-stenting: Post-TEVAR femoral access deployment of Fabulous® (45-150mm) long bare-metal stent with: Proximal overlap ≥3cm with TEVAR graft. Distal extension 2-6cm below renal artery plane. Maximum distal limit: above iliac bifurcation. - Intraprocedural angiography with spinal reference mapping guides precise stent positioning relative to visceral arteries and infrarenal aorta.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
30-day all-cause mortality	30-day all-cause mortality	30 days post-intervention
Ratio of increase in aortic true lumen (%)	Ratio of increase in aortic true lumen(%) including three parameters: Diameter measurement (unit: mm): The total aortic diameter was obtained based on the 2020 SVS/STS reporting standards, and then the specific values of the true lumen diameter and false lumen diameter were obtained as a percentage of the straight line between the two lumens.; Area measurement (unit: mm2): The aortic false lumen area = the true and false lumen area - the true lumen area on the same measurement plane.; The change ratio (%) of true lumen diameter (mm) and area (mm2): Definition: Postoperative true lumen diameter increase ratio: (postoperative - preoperative) / preoperative*100% True lumen diameter increase ratio after follow-up: (current follow-up - last follow-up) / last follow-up*100% Postoperative true lumen area increase ratio: (postoperative - preoperative) / preoperative*100% True lumen area increase ratio after follow-up: (current follow-up - last follow-up) / last follow-up area*100%	1 month, 6 months, 12 months after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Aortic rupture incidence	Aortic rupture incidence	1 month, 6 months, 12 months after surgery
Device-related complications	endoleak, spinal ischemia, organ failure; Classification and incidence rates	1 month, 6 months, 12 months after surgery
False lumen thrombosis grading	Complete: No contrast enhancement; Partial: Partial contrast flow with thrombus; Patent: Full contrast opacification	1 month, 6 months, 12 months after surgery

Collaborators and Investigators

• Sponsor: Yan'an Affiliated Hospital of Kunming Medical University
• Investigators: Principal Investigator: Xunqiang Prof. Liu, M.D., Yan'an Affiliated Hospital of Kunming Medical University

Publications and helpful links

General Publications

• Nienaber CA, Kische S, Zeller T, Rehders TC, Schneider H, Lorenzen B, Bunger C, Ince H. Provisional extension to induce complete attachment after stent-graft placement in type B aortic dissection: the PETTICOAT concept. J Endovasc Ther. 2006 Dec;13(6):738-46. doi: 10.1583/06-1923.1.
• Rong D, Ge Y, Liu J, Liu X, Guo W. Combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair for complicated type B aortic dissections. Cochrane Database Syst Rev. 2019 Oct 30;2019(10):CD013149. doi: 10.1002/14651858.CD013149.pub2.
• Fattori R, Montgomery D, Lovato L, Kische S, Di Eusanio M, Ince H, Eagle KA, Isselbacher EM, Nienaber CA. Survival after endovascular therapy in patients with type B aortic dissection: a report from the International Registry of Acute Aortic Dissection (IRAD). JACC Cardiovasc Interv. 2013 Aug;6(8):876-82. doi: 10.1016/j.jcin.2013.05.003.

Study record dates

Study Major Dates

• Study Start (Estimated): March 31, 2025
• Primary Completion (Estimated): March 31, 2027
• Study Completion (Estimated): March 31, 2027

Study Registration Dates

• First Submitted: March 15, 2025
• First Submitted That Met QC Criteria: March 21, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 21, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: TEVAR; Extension; ATBAD; Long bare metal scaffolding devices
• Additional Relevant MeSH Terms: Dissection, Blood Vessel; Acute Aortic Syndrome; Vascular Diseases; Cardiovascular Diseases; Aortic Diseases; Aneurysm; Aortic Dissection
• Other Study ID Numbers: YAYY-2025-001; 82460098 (Other Grant/Funding Number: National Natural Science Foundation of China)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No