Suitability and durability of multiple internal thoracic artery coronary artery bypasses

The authors evaluate operative and extended outcomes of coronary artery bypass surgery using the bilateral internal thoracic arteries (ITAs) as bypass grafts. The authors conclude that the procedure is viable and of long-term benefit to most patients.

Multiple ITA grafting was met with early enthusiasm by the surgical profession, but skepticism and controversy arose with reports of increased operative morbidity, insufficient graft blood flow, a high incidence of failure of the right ITA, and uncertainty about durability and long-term benefits.

To assess the actual incidence and impact of these complications and long-term results, the authors prospectively studied 500 consecutive patients with multiple ITA bypasses, constituting the closely observed and carefully documented experience of one surgeon over an 11-year period.

Operative mortality in the series of 500 patients was 1.8%, perioperative myocardial infarction (new Q wave) rate was 0.6%, and deep sternal wound infection occurred in 1%. Six patients (1.2%) had strokes, and nine patients (1.8%) were returned to the operating room to control bleeding. One hundred ninety-eight patients who had abnormal stress test results before surgery were retested within 3 months of surgery. Ninety-four percent of these were normal, 3% were nondiagnostic, and 3% were abnormal. After a mean follow-up of 7.1 years (mode, 7.2 years), 87.5% of patients in the sample were alive, and 93.2% of this group have experienced continuing good clinical results (New York Heart Association class I or II). Eighty-nine patients who underwent an angiogram had 90.8% patency rates of ITA bypasses and 84.5% patency of vein grafts. Only two patients required repeat operations.

The operative results did not support the contention that the coronary artery bypass using ITA procedure produces higher than acceptable mortality and morbidity rates. Multiple ITA bypasses can be performed without excessive morbidity, with low reoperation rates and long-term outcomes that should encourage skeptics to reconsider the procedure's clinical value.