Background: Transcatheter atrial septal defect (ASD) closure in the dog was first reported in 2005.
Objectives: Describe the technique and both short- and mid-term outcome of transcatheter ASD closure with the Amplatzer atrial septal occluder (ASO).
Animals: Thirteen client-owned dogs with ASD.
Methods: Records of the initial 13 dogs in which transcatheter ASD closure was attempted at Texas A&M University were reviewed.
Results: All dogs had hemodynamically relevant septum secundum ASD. Two dogs had concurrent congenital abnormalities. ASOs were deployed in 13 dogs and released in 12. Eleven were released by a right jugular approach and 1 by a transatrial approach through a right lateral thoracotomy. Transthoracic echocardiographic estimates of ASD size were 14.0 + or - 5.4 mm (mean + or - 1 standard deviation) with a range of 7-22 mm. Accidental right atrial release occurred in 1 dog and embolization after release occurred in 2 dogs. Transcatheter ASD closure was successful in 10 dogs. Transthoracic color Doppler echocardiography the day after ASD closure indicated complete occlusion in 5 dogs, trivial to mild residual shunting in 4 dogs, and moderate residual shunting in 1 dog. Follow-up echocardiograms (mean of 12.4 + or - 7.4 months postprocedure) were available for 9 dogs. There was no residual ASD shunting in 6 dogs. In 3 of the 5 dogs with postoperative residual shunting it was judged to be decreased and hemodynamically unimportant relative to the dogs' postoperative evaluations. The mean length of event-free survival in the 10 dogs that underwent successful transcatheter ASD closure was 22.2 + or - 10.2 months.