Behavior Of Fresh Autologous Pericardium In High And Low Pressure Vascular Lumen Of Dog

Objectives: Theoretically being non-antigenic and non-calcifying bioprosthesis, fresh autologous pericardium used as cardiovascular implants produces mixed results and little do we know the mechanism of its outcome in vivo. To evaluate the feasibility of the application in high and low pressure vascular lumen, we observed the behavior of autologous pericardium in thoracic aorta and pulmonary artery in dogs.Method: Self-control design was applied. Four groups included two experimental group: pulmonary patch group, thoracic aortic patch group and two control group: pericardium group and aorta wall group. The oval defects in thoracic aorta and main pulmonary were established and fresh autologous pericardium was transplanted as a patch in the descending aorta and main pulmonary artery which were hemi-clamped and the patches was used to close the defects created in the main pulmonary and descending aorta with a continuous running 7-0 prolene suture. The implants were recovered 3 months after operation to observe postoperative calcium content which was assessed by spectrophometry and macroscopic and ultrastructural change. Statistical comparison was performed with two-factor variance of analysis. Result: 1, Fresh implants showed no obvious aneurysmal and thrombotic change but slight conglutination with peripheral tissue. The flaps were smooth and thickening with flbrotic deposition on the luminal aspect and weredifficult to distinguish from arterial wall. An ingrowth of fibrous tissue from the periphery to the centre of the grafts. Without obvious fibrous deposition, some central position of the grafts was thicker than control pericardium. No false aneurysm in the suture line, thrombus and calcification was found. 2, Calcium content determination: To convert the original data to logarithm and then perform two factor variance of analysis. The result showed higher calcium content in pulmonary group (P<0.05) and low calcium content in thoracic aorta group which shows no significant difference from those of control pericardium group and aorta wall group. The two-factor variance of analysis showed no individual difference.3, Electron microscopy findings: New endothelial cells on the luminal surface of aorta and pulmonary patch are smooth and flat with the irregular shape. Having abundant cell organs and integral nuclei, the new endothelium cells are alive. But the cell configuration isdifferent from the control mesothelial cells in pericardium and epithelial cells in aorta that have the tiny villus. Collagen fibre and non-structural change are taken placed under the new endothelium. The coverage of new endothelium is more complete in aortic patch than in pulmonary patch. There is more collagen tissue on the surface of pulmonary patch. Conclusion: 5, The application of autologous pericardium patch isfeasible in high-pressure vessel lumen on thecondition of stable hemodynamics. 6, The application autologous pericardium patch isnot always safe. Many factors that influence theoutcome of the patch should be considered. 7, The new endothelial cells are alive which grow onthe luminal aspect of the patch. It may play a role intissue anti-calcification.8 The outcome of autologous pericardial patch shows a process of mutual blend with neighborhood vessel tissue.