[Experimental study of superior vena caval's reconstruction with ringed E-PTFE grafts].

For evaluating whether 2 types of expanded polytetrafluoroethylene, ringed E-PTFE graft can be utilized for venous reconstruction, especially, for superior vena caval reconstruction or not, the ringed E-PTFE grafts which had 10-15 micron fibril length and 30 micron fibril length were implanted between the innominate vein and the right atrium of the 20 dogs. The grafts were removed for histological and scanning electromicroscopic evaluation at intervals varying from one to twelve postoperative months. Overall patency rate was 62% and severe stenosis at the site of anastomosis was seen in 2 grafts. More than half of the graft showed mild to moderate intimal hyperplasia at the anastomotic sites and the early stage of thrombosis at the middle of the grafts. Mesenchymal cell infiltration was occurred in 46% of the grafts.