Access to the thoracic aorta is best achieved by incising the parietal pleura overlying the aorta and retracting the lung anteriorly. Blunt dissection is used to develop a space between the esophagus and aorta to permit aortic cross-clamping above the diaphragm without damaging the intercostal vessels. When the aorta is collapsed, as in the hypotensive patient, palpation of the naso- or orogastric tube can aid in differentiating the esophagus from the aorta.
