Objective: Stenosis of extracardiac conduit after reconstruction of right ventricle outflow tract is a serious problem, and the purpose of this study was to identify the suitability of broadly pedicled autologous pericardial flap for the reconstruction of pulmonary artery trunk in adult dogs.
Methods: Eight mongrel dogs had replacement of a pulmonary artery trunk with extracardiac conduit, in which prosthetic vascular graft formed the posterior wall and pedicled (group P, n = 5) or free (group F, n = 3) autologous pericardium created the anterior wall. Six months after the operation, pressure gradient across the conduit were measured and put to death for pathological examinations.
Results: Pressure gradient across the conduit in groups F and P was 16.0 +/- 16.8 mmHg and 1.4 +/- 1.7 mmHg respectively. In the microscopic examination, flaps of group P had neo-intimal cells in the innermost layer, abundant cellular component with elastic fiber was seen within the middle layer, and collagen tissue within the outer layer. Conversely, the presence of calcification was shown within collagen fiber layer of all patches in group F. Sparse cellular component and the absence of neo-intimal cells were also observed in group F.
Conclusions: Broadly pedicled pericardial flap is more conceivable to prevent the development of conduit stenosis after right ventricle outflow tract reconstruction, if compared with free pericardial patches.