Is Deep Hypothermic Cardiac Arrest Mandatory in Aortic Arch Surgeries?

Aortic arch surgeries are complex and the choice of optimal cannulation technique remains debated. Central cannulation with deep hypothermic circulatory arrest (DHCA) is widely used for a bloodless operative field but carries risks of neurological injury and variable outcomes between patients. Consequently, centers explore alternative cannulation and cardiopulmonary bypass (CPB) strategies to improve outcomes while reducing morbidity and mortality.

The paper highlights concerns with DHCA, including neurological risks and the critical importance of ischemic time, often necessitating rapid surgery. It references monitoring strategies during DHCA (EEG, SSEP, NIRS, jugular bulb oxygen saturation) and pharmacologic neuroprotection. Cited literature addresses: effects of cooling on EEG and evoked potentials during DHCA; impact of arterial cannulation strategy on outcomes in aortic surgery (meta-analyses and comparative studies); cannulation strategies in acute type A dissection; approaches to circulation management and neuroprotection in intramural hematoma; and comparisons of axillary versus femoral cannulation. The accumulated evidence motivates exploring cannulation strategies that maintain antegrade cerebral and systemic perfusion without DHCA.

Case report of a 16-year-old male with traumatic aortic arch dissection located between the origins of the brachiocephalic and left common carotid arteries, causing stenosis of both. Operative strategy: right axillary artery exposed in the infraclavicular region; an 8-mm Dacron graft anastomosed end-to-side to the artery with continuous Prolene 6-0 sutures; arterial cannulation via the graft. A second arterial cannula placed in the right femoral artery (dual arterial cannulation). Median sternotomy performed. Venous drainage via a two-stage right atrial cannula. CPB initiated under mild hypothermia with flows divided between axillary and femoral cannulas. The three arch vessels were dissected and doubly looped to occlude flow. The heart was arrested with aortic root cardioplegia. Proximal aortic cross-clamp applied just before the brachiocephalic trunk origin; distal clamp at the distal end of the arch. The dissected arch segment was opened, revealing a circumferential intimal tear between the brachiocephalic and left common carotid arteries. The arch was divided into proximal and distal halves; in each, intima, media, and adventitia were buttressed together with Teflon felt using continuous Prolene sutures. The two halves were then re-anastomosed end-to-end with continuous suturing. Deairing was performed by applying an aortic cross-clamp proximal to the aortic root vent, followed by sequential opening of the proximal arch clamp, the distal arch clamp, and the arch vessels. CPB was weaned and decannulation completed per routine.

• Surgical repair of an aortic arch dissection using dual arterial cannulation (axillary and femoral) under mild hypothermia without DHCA was feasible.
• Continuous antegrade cerebral perfusion via axillary cannulation and distal perfusion via femoral cannulation provided a bloodless operative field without time constraints associated with DHCA.
• The patient had an uneventful postoperative course with no neurological deficits.
• Postoperative CT angiography demonstrated a normal-caliber arch with well-flowing branch vessels.

The case demonstrates that dual arterial cannulation can maintain continuous perfusion to the brain and distal organs during aortic arch repair, potentially avoiding the neurologic risks and strict time limitations inherent to DHCA. By providing antegrade cerebral flow through the axillary artery and systemic perfusion via the femoral artery, the technique preserves organ perfusion, may obviate the need for extensive neuromonitoring, and affords a clear operative field for precise anastomosis. The authors argue that, given the drawbacks of DHCA and variable neurologic outcomes, such alternative strategies deserve consideration to enhance safety and reduce morbidity in select aortic arch cases.

Cannulation strategy is pivotal to outcomes in aortic arch surgery. This report suggests that a dual cannulation approach (axillary plus femoral) can provide effective antegrade cerebral and systemic perfusion, enabling arch repair without DHCA and its associated risks, while maintaining an optimal surgical field. Broader adoption and evaluation of such techniques in varied clinical scenarios are encouraged to determine generalizability and optimal use.