Redo coronary artery bypass grafting in patients with patent bilateral internal thoracic artery grafts: Exceptions to a lifetime warranty.

Abstract

To undertake an in-depth review of patients undergoing redo coronary artery bypass grafting (CABG) despite patent bilateral internal thoracic artery (BITA) grafts. From January 1980 to July 2020, 91 of 8108 patients (1.1%) who underwent isolated redo CABG had patent BITAs. Mean age was 62 ± 8.7 years; 81 (89%) were male. Mean age at previous CABG was 52 ± 9.4 years, with reoperation occurring after a median of 10 years. Indications for reoperation, surgical strategies, and outcomes were analyzed. All patients had ischemic symptoms, most commonly unstable angina (65 [71%]). Anatomic drivers of reoperation included progression of native coronary atherosclerosis (63 [69%]), non-BITA graft failure (63 [69%]), and patent but diseased, atretic, or technically compromised internal thoracic artery grafts (ITAs) (34 [37%]; left: 12, right: 18, bilateral: 4). The left anterior descending artery (LAD) was previously bypassed with an ITA in 78 (86%). At reoperation, conduits used included saphenous vein (75 [82%]), radial artery (39 [43%]), and gastroepiploic artery (8 [8.8%]). Coronary targets included circumflex (58 [64%]), right coronary (54 [59%]), LAD (36 [40%]), and diagonal (28 [31%]) arteries. Operative mortality and median survival were 3.3% and 12 years, respectively. Patients with patent BITAs represent a small subset of redo CABG cases, with native coronary disease progression and non-ITA graft failure being the most common reoperation indications. Most patients undergo multivessel grafting, with less than one half needing or requiring a bypass to the LAD. Outcomes are good at centers with experienced surgeons.