The broadly based pericardial flap. A tissue for atrial wall replacement that grows.

The repair of many congenital heart anomalies would be facilitated by a tissue replacement for the atrial wall or pulmonary artery which would grow with the child. Such a tissue has not previously been identified. In 12 puppies a broadly based flap of pericardium was sutured over the right atrial free wall. The atrial wall was excised from beneath the flap. In four animals the flap was then cut away from its pericardial attachments superiorly, inferiorly, and along the phrenic nerve, leaving an autogenous pericardial patch. In the other eight animals the flap was left intact, allowing retention of neural and vascular supply. The animals were put to death 263 +/- 23 days later. In four animals having a pericardial patch, the area of the patch did not increase (94% of original size, NS) despite an increase in body surface area (BSA) to 169% (p less than 0.05) of original BSA. In eight animals with a pericardial flap, the area of the flap increased to 214% (p less than 0.01) of the original size with an increase in BSA to 199% (p less than 0.01) of original BSA. The flap size index (size/BSA) increased to 109% of the original index while the patch size index decreased to 54% of the original, a significant difference (p less than 0.01). The broadly based pericardial flap grew in a manner parallel to BSA increase in these puppies.