The Aortic Surgery Cerebral Protection Evaluation (ACE) Randomized CardioLink-3 Trial

A Randomized Controlled Trial of Axillary vs. Innominate Artery Cannulation for Antegrade Cerebral Protection in Aortic Surgery: The ACE Randomized Trial

The ACE trial is a multicentre, randomized controlled trial comparing axillary vs. innominate artery cannulation for established antegrade cerebral perfusion in patients having aortic surgery (thoracic and aortic arch) requiring deep hypothermic circulatory arrest using a non-inferiority trial design.

Surgery on the thoracic aorta often requires a brief period of deep hypothermic circulatory arrest (DHCA). The most feared complication of aortic surgery is neurological injury, which can range from mild cognitive impairment to more severe injuries such as stroke. Due to the significant morbidity and mortality associated with post-operative stroke and neurological dysfunction, cerebral protection techniques have evolved extensively. A recommended approach to cerebral protection during DHCA is to deliver blood to the brain in an antegrade fashion via the arterial system, so called antegrade cerebral perfusion (ACP). Axillary artery cannulation, a form of ACP, has become the preferred method of neuroprotection for aortic operations requiring DHCA. However, axillary artery cannulation requires more surgical time and presents potential complications such as brachial plexus injury, seromas, and limb ischemia. The present study aims to determine whether a less common alternative strategy, innominate artery cannulation, offers similar neuroprotection compared to axillary artery cannulation and reduces operative times. A total of 110 patients undergoing elective aortic surgery will be randomly assigned to one of the two strategies. The primary outcome will be the number of patients with new ischemic lesions found on post-operative diffusion weighted MRI (DW-MRI) and total operative time.

antegrade cerebral perfusion, innominate artery cannulation, axillary artery cannulation, aortic surgery, deep hypothermic circulatory arrest

The right axillary artery will be exposed via an infraclavicular incision and a Dacron graft sewn to it in an end to side fashion after 5000 units of IV heparin. Following median sternotomy and full systemic heparinization, CPB will be initiated and the patient cooled. The base of the innominate artery will be clamped, and antegrade cerebral perfusion will be provided via the axillary artery. Following completion of the distal open aortic anastomosis, the clamp on the innominate artery will be removed, CPB via the aorta will be resumed and the patient will be rewarmed. After completion of surgery and weaning from CPB, the axillary artery graft will then be removed, the artery repaired and the skin will be closed.

After median sternotomy, systemic heparinization, cannulation of the ascending aorta and right atrium, CPB and systemic cooling will be initiated. The ascending aorta, proximal arch and the base of the innominate artery will be mobilized. Purse-string sutures are placed on the anterior wall of the proximal innominate artery and a pediatric venous cannula inserted using a J wire and sequential dilatation. Circulatory arrest with ACP is provided by clamping the base of the innominate artery and connecting the afferent limb of the CPB circuit to the innominate cannula. Once the distal aortic anastomosis is completed, ACP is discontinued, and full CPB via the aortic graft is resumed. Rewarming and the remaining surgery are then completed.

The primary safety endpoint of this trial is the proportion of patients with new severe ischemic lesions found on post-operative DW-MRI compared with pre-operative MRI.

The primary efficacy endpoint of this trial is the difference in total operative time between the innominate artery cannulation group and the axillary artery cannulation group.

Post-operative sepsis, delirium, seizure, encephalopathy, atrial fibrillation, post-operative myocardial infarction, re-operation

Inclusion Criteria: Age ≥ 18 years. Elective aortic arch operation. Planned open distal anastamosis with deep hypothermic circulatory arrest. Exclusion Criteria: Patients undergoing surgery for aortic dissection or urgent/emergent operation. Patients undergoing surgery for total aortic arch replacement. Patients who are unable to undergo MRI scan (such as due to claustrophobia). Use of an investigational drug or device at the time of enrolment Participation in another clinical trial which interferes with performance of the study procedures or assessment of the outcomes

Chen CH, Peterson MD, Mazer CD, Hibino M, Beaudin AE, Chu MWA, Dagenais F, Teoh H, Quan A, Dickson J, Verma S, Smith EE. Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE CardioLink-3 Randomized Trial. Stroke. 2023 Jan;54(1):67-77. doi: 10.1161/STROKEAHA.122.041612. Epub 2022 Oct 31.

Peterson MD, Garg V, Mazer CD, Chu MWA, Bozinovski J, Dagenais F, MacArthur RGG, Ouzounian M, Quan A, Juni P, Bhatt DL, Marotta TR, Dickson J, Teoh H, Zuo F, Smith EE, Verma S; ACE CardioLink-3 Trial Working Group. A randomized trial comparing axillary versus innominate artery cannulation for aortic arch surgery. J Thorac Cardiovasc Surg. 2022 Nov;164(5):1426-1438.e2. doi: 10.1016/j.jtcvs.2020.10.152. Epub 2020 Dec 1.

Garg V, Peterson MD, Chu MW, Ouzounian M, MacArthur RG, Bozinovski J, El-Hamamsy I, Victor Chu F, Garg A, Hall J, Thorpe KE, Dhingra N, Teoh H, Marotta TR, Latter DA, Quan A, Mamdani M, Juni P, David Mazer C, Verma S. Axillary versus innominate artery cannulation for antegrade cerebral perfusion in aortic surgery: design of the Aortic Surgery Cerebral Protection Evaluation (ACE) CardioLink-3 randomised trial. BMJ Open. 2017 Jun 10;7(6):e014491. doi: 10.1136/bmjopen-2016-014491.