Polytetrafluoroethylene graft for spontaneous coronary dissection: 7-year follow-up. Spontaneous coronary artery dissection remains an exceedingly rare cause of myocardial ischemia. The patients are usually young and female, and the dissection is frequently fatal. The use of polytetrafluoroethylene as an aortocoronary conduit is generally followed by early occlusion. We report a case of spontaneous right coronary dissection in which a polytetrafluoroethylene graft was placed that was observed to remain patent by angiography at least 72 months after operation. 