Pericardium as a thoracic aortic patch: glutaraldehyde-fixed and fresh autologous pericardium

The repair of complex coarctation of the aorta often requires an aortic patch. Prosthetic patches lack growth potential and are associated with an increased incidence of aneurysm formation opposite the patch. We compared buffered glutaraldehyde-fixed patches, used in six animals (group 1), and untreated autologous pericardial aortic patches, used in five animals (group 2). Weanling pigs underwent pericardial patch replacement of a 1 X 2-cm diamond-shaped segment of the lateral wall of the descending thoracic aorta at the level of the aortic isthmus. Six months following patch aortoplasty, the animals were killed and the in situ patch dimensions were measured and compared to the measurements obtained at implantation. The increases in length, recorded as mean percentage change +/- SEM, were 34.7 +/- 3.7% for group 1 and 102.8 +/- 20.3% for group 2 animals; the increases in width were 91.4 +/- 31.7% for group 1 and 192.4 +/- 31.4% for group 2. The percentage changes for both length and width were significantly different between groups (P less than 0.05). Pull strength testing of standard-size patch samples demonstrated no significant difference in tensile breaking load between groups: group 1 = 959 +/- 277 g, group 2 = 795 +/- 86 g. Thoracic aortography revealed no evidence of stenosis or aneurysmal dilation in either group. Autologous pericardium is resilient, strong, and readily available and has expansile potential that makes it an ideal aortic patch material. We conclude that glutaraldehyde fixation does not provide additional strength and limits graft expansile potential when compared to untreated pericardium.