Coronary Artery Bypass Grafting Using an Arteriovenous I-Conduit: Benefits and Drawbacks

The Anaortic Technique with Bilateral Internal Thoracic Artery Grafting - Filling the Gap in Coronary Artery Bypass Surgery

Coronary artery bypass grafting (CABG) has consolidated its role as the most effective procedure for treating patients with advanced atherosclerotic coronary artery disease, reducing the long-term risk of myocardial infarction and death compared to other therapies and relieving angina. Despite the recognized benefits afforded by surgical myocardial revascularization, a subset of higher-risk patients bears a more elevated risk of perioperative stroke. Stroke remains the drawback of conventional CABG and has been strongly linked to aortic manipulation (cannulation, cross-clamping, and side-biting clamping for the performance of proximal aortic anastomoses) and the use of cardiopulmonary bypass. Adoption of off-pump CABG (OPCAB) is demonstrated to lower the risk of perioperative stroke, as well as reducing the risk of short-term mortality, renal failure, atrial fibrillation, bleeding, and length of intensive care unit stay. However, increased risk persists owing to the need for the tangential ascending aorta clamping to construct the proximal anastomosis. The concept of anaortic (aorta no-touch) OPCAB (anOPCAB) stems from eliminating ascending aorta manipulation, virtually abolishing the risk of embolism caused by aortic wall debris into the brain circulation. The adoption of anOPCAB has been shown to further decrease the risk of postoperative stroke, especially in higher-risk patients, entailing a step forward and a refinement of outcomes provided by the primeval OPCAB technique. Therefore, anOPCAB has been the recommended technique in patients with cerebrovascular disease and/or calcification or atheromatous plaque in the ascending aorta and should be preferred in patients with high-risk factors for neurological damage and stroke.

Clinical Validation of a Coronary Surgery Technique That Minimizes Aortic Manipulation

BACKGROUND

To minimize aortic manipulation and maximize use of arterial conduits are aims of modern coronary surgery.

METHODS

From March 2012 to October 2016, 890 consecutive patients with multivessel coronary disease underwent isolated coronary operations using both internal thoracic arteries (ITAs). In 205 (23%; mean age, 67.6 ± 9.2 years), the right ITA was proximally transected and used as a free graft, while its in situ stump was elongated with a saphenous vein graft. The new arteriovenous I conduit was directed to the inferolateral cardiac wall. Operative data and early outcomes of these patients (I group) were compared with the remaining 685 patients (control [C] group). Early and late outcomes were also compared in 184 pairs identified with propensity score matching.

RESULTS

Between the I and C groups there was no significant difference in expected operative risk (European System for Cardiac Operative Risk Evaluation II, p = 0.28), although diseased ascending aorta (p < 0.0001) and critical preoperative state (p = 0.027) were more frequent in the I group. Despite a higher number of coronary anastomoses (mean, 4 ± 0.9 vs 3.7 ± 1, p < 0.0001), cardiopulmonary bypass time was shorter in the I group both in overall (86.7 ± 23.7 vs 105.7 ± 34.2 minutes, p < 0.0001) and matched series (86.8 ± 24.1 vs 108.8 ± 31.9 minutes, p < 0.0001). In-hospital mortality (1% vs 1.9%, p = 0.54) and the rates of postoperative complications were similar. During the follow-up period, no intergroup difference was found in matched patients in the nonparametric estimates of freedom from all-cause death (p = 0.39) and major adverse cardiac and cerebrovascular events (p = 0.44).

CONCLUSIONS

Surgery using this arteriovenous I conduit is safe, minimizes aortic manipulation, shortens cardiopulmonary bypass time, and aids complete revascularization.