A new device as an open stent graft for extended aortic repair: a multicentre early experience in Japan.

Objectives: Open stent grafting for extended aortic repair has been widely carried out around their world. We reported the effectiveness of a new device as an open stent graft for extended aortic repair.

Methods: A new device was used as an open stent graft in this study. The graft part of the device has a woven structure made of Nitinol wire, a superelastic/shape-memory alloy. The subjects of this study were patients aged 20-84 with aneurysms (n = 38) or aortic dissection (n = 22) in the thoracic aorta, including the distal aortic arch and the proximal descending aorta. This study was a multicentre, non-blinded study. The follow-up period was 36 months.

Results: Three subjects (5.0%) died during hospitalization due to multiorgan failure. Spinal cord injury (SCI) was observed in 4 subjects (6.7%): paraplegia in 1 and paraparesis in 3 subjects. The 3-year survival rate was 76.7% overall: 68.4% for the subjects diagnosed as having aortic aneurysms (the aortic aneurysm group) and 90.9% for those having aortic dissection (the aortic dissection group). For the aortic aneurysm group, thrombus formation in the aortic aneurysm was observed in 97% of the patients 6 months after operation, and in 100% 12 months after operation. Meanwhile, for the aortic dissection group, with regard to the false lumen of aortic dissection, thrombus formation was observed in 94% of the patients 6 months after operation, in 94% 12 months after operation and in 100% 24 months after operation. Expansion of the aortic aneurysm sac was observed in 2 subjects (6.1%). Among these 2 subjects, endoleak was observed in 1 subject, which was improved by additional thoracic endovascular aortic repair.

Conclusions: The safety and effectiveness of this investigational device was verified over a period up to 36 months after operation. A long-term follow-up would be necessary to further verify the effectiveness of the device in the future.