Uncovered Chimney Stent Graft for Renal Arteries With the Nellix Endovascular Aneurysm Sealing Technique

Abstract

Purpose: To describe the application of uncovered chimney stent grafts with the Nellix endovascular aneurysm sealing technique (ChEVAS) for juxtarenal abdominal aortic aneurysms (JAAAs).

Case report: Two patients with JAAA and multiple comorbidities were considered unfit for open surgery and were selected for an endovascular approach. Fenestrated and branched endografts were too expensive, and a chimney endovascular approach was considered inappropriate for the relatively high incidence of proximal type I endoleak and graft migration. ChEVAS was performed successfully with the novel addition of uncovered chimney stents to further reduce costs and possibly improve target vessel patency. JAAA exclusion and visceral vessel patency was confirmed at 18-month follow-up.

Conclusion: ChEVAS with bare chimney stents is technically less complex, potentially reduces access complications and procedural costs, and may improve long-term patency compared to alternative techniques. Results at 18 months seem promising, but strict follow-up is necessary as the long-term durability is unknown.

Keywords: aortic aneurysm; balloon-expandable stent; chimney technique; juxtarenal abdominal aortic aneurysms; sac-sealing endoprosthesis; stent-graft.