Purposes: When placing stent grafts, deployment accuracy and birdbeaking due to inadequate conformability and device apposition along the inner curvature of the arch have been encountered. The new Conformable GORE® TAG® Thoracic Endoprosthesis (CTAG) is designed to have enhanced compression resistance and improved conformability in difficult anatomy. The present study compared the deployment accuracy and conformability of the CTAG Device with TAG Device.Method: Deployment accuracy and birdbeaking was compared of CTAG Device and TAG Device implantation for initial treatment of thoracic aortic aneurysm conducted by our department between March 2010 and March 2012. Deployment accuracy was defined as the distance between the actual and intended device implantation locations measured from DSA images.Results: Deployment accuracy at the time of implantation (mean ± SD) was significantly better for the CTAG Device compared to the TAG Device (2.2 ± 1.7 mm vs. 4.4 ± 3.0 mm, P <0.05). Also, while birdbeaking was seen in 8 of 20 cases (40%) for the TAG Device, it was only seen in 1 of 12 cases (8%) for the CTAG Device.Conclusion: The present study found enhanced deployment accuracy and conformability along the aortic arch using the CTAG Device compared to the previous-generation TAG Device.