Balloon atrial septostomy in complete transposition of great arteries in infancy.

The results of 26 completed balloon atrial septostomies in complete arterial transposition in infancy are described, and complications discussed. Of 7 deaths following this procedure, 3 were clearly or probably related to it or to its failure to produce an adequate septal defect, while 4 were unrelated. Atrial perforations occurred on 4 occasions. Necropsy information regarding the defects produced by the procedure is given. Anatomical features of the fossa ovalis appear to determine the size of the defect created. The effect of the procedure is illustrated by photographs of representative necropsy specimens. Apparently adequate initial defects do not guarantee satisfactory long-term palliation, and 4 of iI infants followed for more than 6 months after effective initial palliation have required surgical procedures to provide