Long-term results of mammary artery implants

Eighty out of eighty-six patients (93%) with mammary artery implants were followed postoperatively for an average of three and a half years. The immediate mortality rate was 7% (6 cases), and the late mortality was 6% (5 cases). All had angina preoperatively. Twenty-four had a history of myocardial infarction and thirty-one were on limited physical activity, because of the pain. After surgery, thirty-three (45%) became asymptomatic. The angina improved significantly in thirty-five (47%) and remained unchanged in six (8%). Improvement in ventricular repolarization on ECG was observed in 69% of the patients. Postoperative cineangiography was performed in twenty-three patients; thirteen with single and ten with double implants. Out of the total of thirty-three implants, four (12%) were obstructed and twenty-seven patent (82%); twenty were in two cases of double implant, only one implant could be satisfactorily studied effectively functioning (61%). No obstructions were seen in the single implants. Non functioning implants were found in five (38%) of the thirteen single implants and in two of the twenty double ones (10%). The highest incidence of obstruction or non-functioning implants occurred in the group that did not show improvement (43%). This rate fell to 40% in the group that had some improvement and to 29% in those that were completely asymptomatic. Twelve of the eighteen patent mammary implants (67%) on the anterior wall of the left ventricle and eight of nine (89%) on the lateroinferior wall, established collateral circulation to the coronaries. Indication for surgery was considered satisfactory for nineteen out of the twenty-three patients and poor in four. There were two cases of obstruction of the implant (7%) in the group where surgery was correctly indicated and three of the twenty-three (11%) patent implants were non-functioning. Clinical improvement of the angina occurred in 84% in the first group and 50% in the other. In conclusion, this technique of indirect revascularization of the myocardium is valid for patients with severe diffuse lesions of the coronaries with a collateral network and preserved myocardial contractility.