A study of the sequential morphologic changes after manual coronary endarterectomy.

Manual coronary endarterectomies heal in the long-term by a poorly understood process of myofibrointimal proliferation. A retrospective analysis of detailed cardiovascular pathologic examinations of 51 patients dying at varying intervals after endarterectomy provides insight into the sequence of this proliferative response. Twenty-one patients died within 7 days, 6 at 8 to 30 days, 3 at 31 days to 6 months, 4 at 6 months to 5 years, and 17 at more than 5 years after endarterectomy. The observations made suggest that the denuded arterial surface heals after the fibrin-platelet mural thrombus that covers it is organized and is replaced by fibrosis and myofibroblast proliferation. In unusual cases proliferation is exuberant, resulting in significant restenosis, an outcome in which recurrent atherosclerosis contributes to only a minor degree. This is the first series in which the sequential reparative changes at varying times after manual coronary endarterectomy have been studied.