Constrictive perivenous mesh prosthesis for preservation of vein integrity. Experimental results and application for coronary bypass grafting.

Saphenous veins undergo dramatic morphologic changes when used as coronary bypass grafts, and careful preparation of the graft alone is inadequate in preventing these changes. In this study, the use of a constrictive mesh for vein graft was evaluated. Fourteen sheep were subjected to a 5 cm resection of the carotid artery. Six sheep (Group A) received a jugular vein interposition graft, and the other eight sheep (Group B) received a jugular vein graft on which the constrictive mesh had been applied. The diameter of grafts in Group A was 14 +/- 1 mm compared with 7 +/- 0.5 mm for Group B (p = 0.05). The animals were put to death 4 months later. Scanning electron microscopy showed a disruption of the endothelial lining in Group A and a normal endothelium in Group B. Microscopy showed a statistical difference between Groups A and B regarding regularity and thickness of the intimal hyperplasia. Group B showed a moderate and regular intimal thickening and increased vasa vasorum. This indicates that distention and subsequent damage of the vein graft may be minimized by use of a constrictive mesh. Saphenous grafts surrounded by this constrictive mesh were inserted in four patients. Vein diameters were, respectively, 5, 4.3, 3.5, and 3.5 mm before meshing. After insertion in the mesh, vein diameters were 4.3, 3.5, 2.8, and 2.5 mm, respectively. Angiography performed 2 months later showed patent grafts of regular caliber.