What is the best arterial cannulation site in a complicated patient with acute type A aortic dissection?

In the article by Totaro and Argano [1], the authors performed antegrade perfusion using an innovative technique to treat cerebral and peripheral malperfusion occurring during acute type A aortic dissection (AADA) repair. The technique consists of a double Y-shaped connector on the arterial line including the descending aortic cannulation and selected cannulation of epiaortic vessels. The authors are to be congratulated on their successful dissection repair with this technique. In light of this interesting report, one question has to be raised: what is the best arterial cannulation site in a complicated patient with AADA? Surgical repair of AADA continues to present a challenge for the cardiovascular surgeon and is still associated with an increased risk of perioperative mortality and morbidity due to potential malperfusion of visceral organs and the brain. To reduce these complications, several arterial inflow sites have been proposed for central and peripheral cannulation. Possible inflow sites for arterial cannulation are the femoral artery, the iliac artery, the brachial artery, the axillary and subclavian arteries, the carotid and innominate arteries, the ascending aorta, the transverse arch of the aorta, the descending aorta, and the apex of the left ventricle. The best arterial cannulation site during the conduct of cardiopulmonary bypass to repair AADA is not clearly defined and influenced by many factors and depends on the surgeon's experience. The most popular sites for cannulation are the femoral arteries or the axillary arteries. Satisfactory results have been published by these cannulation approaches [2, 3]. Femoral arterial cannulation remains the preferred approach for surgical repair in patients with AADA. However, it produces retrograde arterial perfusion. Retrograde perfusion may cause malperfusion with consequent neurologic injury or abdominal organ ischemia and may cause retrograde embolization from the atherosclerotic aortic wall. In contrast, the axillary artery is an alternative site for arterial cannulation that provides antegrade arterial perfusion during surgery for AADA. We have mostly used right axillary artery cannulation for arterial perfusion in all our patients. Maybe, the left axillary artery could be used by the authors as a primary site for cannulation in their complicated patient. In our practice, there were no complications related to this cannulation technique. Accordingly, we think that axillary cannulation is easy to establish and may safely be used for arterial inflow in AADA. Contrary to that described by Fusco et al., we also think that it is not safer to use femoral cannulation. Another access should be chosen in patients with AADA extending into the innominate artery or in emergency situations with highly unstable hemodynamics. Central cannulation can be another option in these situations but has been mainly reported as a bail-out technique when other cannulation options are not available [4–6]. However, direct cannulation of the dissected ascending aorta is a new surgical approach using a guide-wire technique such as Seldinger's method under direct-ultrasonographical examination. It has not been used widely owing to concerns over the fragility of the vessel. Transventricular cannulation of the ascending aorta is also another attractive procedure. The cannula was inserted through an apical ventriculotomy into the left ventricle and then through the aortic valve into the true lumen of the ascending aorta. As cardivascular surgeons, we must be adaptable to change and open to new predicaments.