EXTENSIVE ENDARTERECTOMY OF THE LEFT ANTERIOR DESCENDING CORONARY-ARTERY COMBINED WITH CORONARY-ARTERY BYPASS-GRAFTING

Background: Complete revascularization of a diffusely diseased left an terior descending (LAD) coronary artery can be accomplished by extensi ve endarterectomy in conjunction with coronary artery bypass grafting (CABG). The present study was designed to assess the safety of the pro cedure, and which techniques lead to the best short- and long-term res ults. Methods: Between January 1990 and October 1994 106 patients unde rwent extensive open endarterectomy of the LAD coronary artery combine d with CABG at our institution. This group constituted 4.9% of all pat ients undergoing CABG during this period. The mean age of those studie d was 64.4+/-9.2 years and 92% were male. In 22 patients (21%) the pro cedure was a repeat CABG and 12% had had percutaneous transluminal cor onary angioplasty prior to the operation. Ninety-one per cent of the p atients were in Canadian Cardiovascular Society (CCS) angina class 3 o r 4, 91% had three-vessel disease and 36% had unstable angina at the t ime of surgery. The mean preoperative left ventricular ejection fracti on was 53.6+/-14.9% (range, 15-80%). The internal mammary artery (IMA) was used to bypass the LAD coronary artery in 40 patients (38%) and a saphenous vein graft (SVG) was used in 66 patients. In 25 of the IMA bypass group an additional venous patch was used (IMA + P). Results: T he overall mortality rate was 9.4% (10 patients), including seven imme diate postoperative deaths. When the IMA was used as a conduit the mor tality rate was only 5.0%. There were seven (6.6%) postoperative non-f atal myocardial infarctions. There was a low incidence of other postop erative complications, similar to that following CABG without endarter ectomy performed during the same period. Multivariate analysis identif ied emergency operation, two-vessel endarterectomy and female sex as i ndependent risk factors for mortality. Upon follow-up study of 94 hosp ital survivors (98%), at a mean of 26.5 months (range, 1-48 months), a ll endarterectomy patients were in CCS class 1 or 2. Seventy-eight pat ients (83%) had an excellent postoperative exercise tolerance and the left ventricular function was preserved. The 4-year survival rates wer e 88% and 96% and the cardiac event-free survival rates were 74% and 8 7% in the SVG and IMA groups respectively. Conclusions: Complete revas cularization of the diffusely diseased LAD coronary artery can be acco mplished by adjunctive open endarterectomy with a degree of operative risk (mortality 9% and incidence of non-fatal myocardial infarction 7% ). The immediate and medium-term results are improved when the IMA is used as a conduit, with or without additional venous patch. Independen t risk factors for mortality were two-vessel endarterectomy, female se x and emergency operation. The long-term results revealed an overall s urvival rate of 92% and a cardiac event-free survival rate of 79% at 4 years, as well as excellent functional results.