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.