A PATENT INTERNAL MAMMARY ARTERY GRAFT DECREASES THE RISK OF REOPERATIVE CORONARY-ARTERY BYPASS-SURGERY

In order to evaluate the potential risks of a patent internal mammary artery bypass at reoperative coronary artery bypass grafting, we have reviewed the records of 233 consecutive patients undergoing reoperativ e coronary artery bypass grafting between 1 January 1991 and 31 Decemb er 1993, including 209 patients having an occluded mammary graft or no mammary graft (Group I) and 24 patients having a patent mammary graft (Group II). With regard to preoperative patient characteristics, the only significant differences between the groups were: Group II patient s had a higher preoperative left ventricular ejection fraction than di d Group I patients (63.7% +/- 8.9% vs 52.1% +/- 10.1%, p < 0.001); and Group II patients had received fewer grafts per patient than had pati ents in Group I (2.2 +/- 1.1 vs 3.6 +/- 1.4 grafts per patient, p < 0. 001). There were no entry injuries to the grafts or to the heart in ei ther of the groups. No perioperative mortality was encountered in Grou p II, while 11 patients died in Group I (p < 0.05). Group II had a sig nificantly higher incidence of reexploration for post-operative bleedi ng, whereas Group I had a significantly higher incidence of low postop erative cardiac output. The incidence of all other perioperative compl ications did not differ between the groups. The results of this study support the use of mammary grafts even in patients who are likely to n eed repeat coronary artery bypass grafting and certainly does not disq ualify such patients from a 2nd operation.