Surgical repair technique
Median sternotomy and cardiopulmonary bypass (CPB) was performed to all patients. The thymus was totally excised and the pericardium was harvested. Straight tip 8Fr (2.7 mm) arterial cannula (RMI, Edwards Lifesciences LLC, Irvine, CA) was inserted into the distal ascending aorta and advanced into the innominate artery for antegrade selective cerebral perfusion (ASCP) during the aortic arch repair. No additional ductal aortic cannulation was performed. Distal perfusion was maintained through the arterial duct by snaring both pulmonary artery branches and keeping the heart filled during cooling. Near-infrared spectroscopy (NIRS) monitoring was performed. Usually, it took about 10-15 minutes to reach the desired core temperature. The Alfa-stat strategy was used in acid-base management for cerebral protection. Aortic arch repair was performed first in all patients. Aortic arch vessels, duct and descending aorta were dissected free. During moderate hypothermia (26°C), aortic clamp was inserted between the innominate and left carotic artery to maintain selective cerebral and coronary flow. The flow rate was adjusted at about 50 ml/kg per min. The mean blood pressure of the right radial artery was sustained at about 40-50 mmHg, and the mean hematocrit level was sustained at around 30 %. Yasargil neurovascular clips were used to close the left carotid and left subclavian arteries. The descending aorta was clamped as far distally as possible with a side clamp. Arterial duct was ligated and resected from the aortic end. The aortic arch was incised until proximal aortic clamp. After all ductal tissue was resected, distal descending aorta was anastomosed to the aortic arch to form a native posterior wall. Distal descending aorta was incised anteriorly and a pericardial patch was sutured to augment the anterior wall of the aortic arch. When the suture line approaches to the aortic clamp, innominate artery was snared over the aortic cannula and ASCP was commenced. At the same time, tepid blood cardioplegia was given. Aortic clamp was moved to the proximal ascending aorta and arch incision was extended to the midportion of the ascending aorta. Remaining of the pericardial patch was sutured to cover the rest of the aortic incision. After de-airing of the aorta, clamps were removed, aortic cannula moved into the aortic arch and whole body perfusion was started. During rewarming pulmonary artery banding or intracardiac repairs were performed.