Toward stroke‐free coronary surgery: The role of the anaortic off‐pump bypass technique

Abstract

Surgical coronary revascularization remains the preferred strategy in a significant portion of patients with coronary artery disease due to superior long‐term outcomes. However, there is a significant risk of perioperative neurologic injury that has influenced guideline recommendations. These complications occur in 1%–5% of patients, ranging from overt neurologic deficits with permanent disability, to subtle cerebral defects noted on neuroimaging that may result in slow cognitive and functional decline. The primary mechanism by which these events occur is thromboembolism from manipulation of the ascending aorta. This occurs during cardiopulmonary bypass, aortic cross‐clamping, and partial occlusion clamping (side clamp). Elderly patients and patients with aortic atheroma are, therefore, at significantly increased risk. Initial surgical techniques addressed this by aggressively debriding or replacing the ascending aorta during coronary artery bypass grafting (CABG). Strategies then moved toward minimizing aortic manipulation through pump‐assisted beating heart surgery and off‐pump surgery with partial occlusion clamping or proximal anastomosis devices. Finally, anaortic off‐pump CABG aims to avoid all manipulation of the ascending aorta through advanced off‐pump grafting techniques combined with in situ and composite grafts. This has been demonstrated to result in the greatest reduction in risk. Establishing successful anaortic off‐pump CABG programs requires subspecialization and focused interest groups dedicated to advancing CABG outcomes.

Total-arterial, anaortic, off-pump coronary artery surgery: Why, when, and how

“…The main cause of perioperative stroke remains emboli, and the main source of emboli stems from the aortic manipulation associated with cannulation, "sandblasting" from the aortic cannula inflow jet, crossclamping, and proximal anastomoses that are inherent to the on-pump, arrested heart CABG technique. 17 Perioperative and delayed stroke have been shown to have a highly significant impact on mortality, with a meta-regression analysis showing that minimizing aortic manipulation, rather than intrinsic patient characteristics, had a protective effect on neurologic outcomes. 18 A network meta-analysis performed by our group in 2017 identified that stepwise reduction and ultimately elimination of aortic manipulation resulted in superior neurologic outcome (and also superior early mortality, renal failure, bleeding, atrial fibrillation, and shorter length of intensive care) (Figure 1).…”

“…The main cause of perioperative stroke remains emboli, and the main source of emboli stems from the aortic manipulation associated with cannulation, “sandblasting” from the aortic cannula inflow jet, crossclamping, and proximal anastomoses that are inherent to the on-pump, arrested heart CABG technique. 17 Perioperative and delayed stroke have been shown to have a highly significant impact on mortality, with a meta-regression analysis showing that minimizing aortic manipulation, rather than intrinsic patient characteristics, had a protective effect on neurologic outcomes. 18 …”

Embolization during cardiac surgery; to prevent or intercept

“…Operative mortality is increased 12-fold in patients with stroke. 8,9 Off-pump and anaortic techniques reduce embolization in patients undergoing CABG and may protect against stroke. 9 What is clear is that embolization is the underlying mechanism of stroke in a significant proportion of cardiac surgical patients.…”

“…Stroke rates of ~1% are noted after cardiac surgery but may be much higher depending on the procedure and patient characteristics, especially severe aortic atherosclerosis. Operative mortality is increased 12‐fold in patients with stroke 8,9 . Off‐pump and anaortic techniques reduce embolization in patients undergoing CABG and may protect against stroke 9,10 .…”

“…Operative mortality is increased 12‐fold in patients with stroke 8,9 . Off‐pump and anaortic techniques reduce embolization in patients undergoing CABG and may protect against stroke 9,10 . Controversy exists as to whether such techniques should be employed routinely, or in the setting of known or suspected aortic atherosclerosis.…”