Aims: To investigate the implantation safety, anatomic performance and septal alignment of the Occlutech Figulla Flex occluder (FFO) device, an atrial septal defect (ASD) closure device with specific left-sided deployment characteristics and right-sided septal alignment properties. Methods and results: Between January 2011 and December 2013 we prospectively collected the change of orientation of the device to the septum during the release process and the feasibility of implantation of the FFO in 122 patients. The mean age was 10.7 years (+/- 10.2), weight 32.9 kg (+/- 20.3), and height 129.4 cm (+/- 30). Devices used were 9 (n=13), 10.5 (n=16), 12 (n=16), 15 (n=39), 18 (n=17), 21 (n=8), 24 (n=5), 27 (n=7) and 30 nun (n=3) in size. No additional implantation techniques were required. Before release, the mean angles of the left and right-sided discs were 29.2 degrees (+/- 9.9 degrees) and 43.4 degrees (+/- 9.2 degrees) to the body axis, and 18.7 (+/- 8.7 degrees) and 27.0 degrees (+/- 10 degrees) immediately thereafter. Thus, there was only a slight change in orientation of the left-sided (10.6 degrees +/- 7.5 degrees) and right-sided (16.3 degrees +/- 7.9 degrees) discs. Conclusions: The design of this occluder system results in an ideal septum alignment which increases its feasibility as well as patient safety during implantation.