Background: We use the left internal thoracic artery (LITA) even when flow is very low. In this study, we investigated midterm outcome of coronary artery bypass graft surgery with low free-flow LITA.
Methods: One hundred patients undergoing coronary artery bypass graft surgery using LITA with a free flow of less than 20 mL/min were reviewed. The mean follow-up duration was 47.4 months, ranging from 1 to 65 months. Graft angiography was performed postoperatively. The diameter of the LITA was assessed angiographically. Cumulative graft patency, cardiac-related event-free rate, and actuarial survival rate were calculated by the Kaplan-Meier method.
Results: An early postoperative Doppler study showed that the diastolic-to-systolic ratio in the LITA was 1.76 +/- 0.33. A 1-month postoperative angiography revealed LITA string sign in 2 patients. One had a percutaneous coronary intervention, whereas string sign was not detected in the second patient, and LITA patency showed a marked improvement in 1-year postoperative angiogram. One month postoperatively the LITA diameter was 1.6 +/- 0.4 mm, and significantly enlarged in the second angiogram (1.9 +/- 0.4 mm, p = 0.0003). There was a significant correlation between the diameter of the LITA and the left anterior descending coronary artery (r = 0.889, p = 0.0001). The cumulative graft patency rate at 1 and 4 years was 99.0% and 94.3%, respectively. The cardiac-related event-free rate at 1 and 5 years was 97.0% and 93.3%, respectively. The actuarial survival rate at 5 years was 97.1%.
Conclusions: Even with a very low LITA free flow, graft function improves with LITA growth, if there was no mechanical damage that impedes recovery.