Findings Published for Gore Conformable Stent Graft to Treat Acute Complicated Type B Dissection

August 11, 2015—In the Journal of Vascular Surgery, Richard P. Cambria, MD, et al published the results of a multicenter clinical trial of a conformable stent graft for the treatment of acute complicated type B dissection (2015;62:271–278). 

According to the investigators, this study was designed to determine the safety and efficacy of the conformable thoracic endoprosthesis device for patients with acute complicated type B aortic dissection, defined as malperfusion or rupture or both.

The study, which evaluated the Conformable TAG thoracic endoprosthesis (Gore & Associates), was first presented at the Late-Breaking Trials session of the Society for Vascular Surgery’s 2012 Vascular Annual Meeting in National Harbor, Maryland.

As summarized in the Journal of Vascular Surgery, this prospective, multicenter, nonrandomized single-arm study included 50 patients with complicated type B aortic dissection treated at 26 sites in the United States between January 2010 and January 2012. The primary safety endpoint was all-cause mortality through 30 days after treatment, and the primary efficacy endpoint was exclusion of the primary entry tear (core laboratory adjudicated) at 1-month follow-up. Secondary endpoints included false lumen thrombosis, dissection-based reintervention rate, and aortic rupture.

The investigators reported that all device implants were successfully completed. Six patients (12%) required additional device implantations ≤ 1 year from the index procedure. There was no conversion to open repair at 1 year. Exclusion of the primary entry tear at 30 days occurred in 97.5% of patients. 

All-cause mortality through 30 days was 8%. Survival was 88% at 1 year and 85% at 2 years. At 1 year after treatment, 35.1% of patients had experienced a decrease of ≥ 5 mm in overall diameter in the treated segment of the aorta. From pretreatment to the 36-month follow-up, the average minimum true lumen area increased by 206.3 mm², and the average maximum false lumen area decreased by 313.4 mm². 

Additionally, the 30-day stroke rate was 18%; none were fatal, and one permanent deficit occurred. Four patients (8%) experienced spinal cord ischemia of any severity but without any permanent or significant deficits. New aortic dissection (three retrograde, two de novo) occurred in five patients (10%). The secondary intervention rate was 18%.

The investigators concluded that treatment with the Conformable TAG thoracic endoprosthesis produced favorable perioperative and intermediate level clinical and anatomic outcomes. In particular, an operative mortality of 8% in this cohort is comparable to that noted in a SVS objective performance criteria publication. Late survival in this cohort compares favorably with historical data referable to complicated type B dissection, stated the investigators in the Journal of Vascular Surgery.