Editor,—Rigby's editorial on transcatheter closure of atrial septal defects is a generally well written review,1 but several misconceptions pertaining to buttoned device are apparent.

Device delivery sheath—Rigby states that the buttoned device is delivered through a 6–8 F catheter. In each of the publications on this device,2-7 it is clearly stated that the device is delivered via an 8–9 F sheath.

Device retrieval—Rigby stated that the retrieval is difficult. The device can easily be retrieved transvenously7 with the help of the loading wire. To prevent inadvertent disconnection of the loading wire with the occluder, we use an additional snare. Even after release from the loading wire, the device can be retrieved by use of a simple snare. However, the device is damaged during the retrieval and cannot be reused.

Embolisation rate—The embolisation rate quoted by Rigby for the buttoned device was 10%, which is very high and we believe is unsupported by the data. In the first 180 implantations in the international trial,7 there …