Myointimal hyperplasia in vein collars for ePTFE grafts.

OBJECTIVE To understand the cause of intermediate ePTFE graft failure when a venous boot is used. This might give insight into the improvement in patency that results from the use of a venous boot. DESIGN A histological and radiological study of failed and failing grafts. METHODS A review of patients operated upon in St Mary's Hospital under the care of a single consultant. RESULTS Four anastomoses were retrieved following irretrievable occlusion and found to have myointimal hyperplasia at the function between the ePTFE graft and collar. The artery was relatively spared. In a further six patients these results have been corroborated by angiography. CONCLUSIONS Myointimal hyperplasia occurs at the interface between ePTFE and vein collar and the recipient artery is relatively spared. This manipulation of the site of myointimal hyperplasia may result in improved patency rates.