Is a patent internal thoracic artery-to-left anterior descending artery still a risk factor in patients undergoing isolated redo coronary artery bypass grafting?

OBJECTIVE

To compare outcomes of redo coronary artery bypass grafting (CABG) in the setting of a patent internal thoracic artery (ITA) to left anterior descending artery (LAD) (group 1) versus those with a stenotic ITA-LAD or without ITA-LAD (group 2).

METHODS

From January 1990 to January 2023, 5616 patients underwent isolated redo CABG at the Cleveland Clinic-1792 in group 1 and 3824 in group 2-following institutional reoperative protocols. End points included ITA injury, major postoperative morbidities, and operative mortality. Mean age was 64 ± 9.0 years for group 1 and 66 ± 8.7 for group 2. Propensity-score matching yielded 1762 matched patient pairs.

RESULTS

Patent ITAs were injured in 1.8% (33/1792), with 32 of 33 (97%) LITAs. Eight (25%) adhered to the sternum, 6 (19%) adhered to the chest wall, and 1 (3%) crossed the midline. A single right ITA injury (3%) was adherent to the sternum. Twelve (36%) were managed by primary suturing and the remaining with complex reconstructions. Occurrence of major complications was similar between groups 1 and 2. Postoperative assist devices, including intra-aortic balloon pumps (7/1762 [0.40%] vs 6/1762 [0.34%], P = .78), were used infrequently. Operative mortality was 3.4% (57/1666) in group 1 and 3.2% (52/1626) in group 2 (P = .72) - 3.1% (1/32) among those with an injured patent ITA-LAD versus 3.4%(56/1634) without injury (P > .99).

CONCLUSIONS

Redo CABG with a patent ITA-LAD is technically demanding and carries risk of ITA injury. Graft adherence to the sternum or chest wall is a particular risk, often related to conduct of the primary operation. With careful planning, reoperation can be performed safely in select patients with effective operative strategies and techniques.