Surgical technique
Following median sternotomy and thymus removal, an autologous pericardial patch was harvested and fixed in glutaraldehyde. Figure 1 summarizes surgical technique applied in our center. The brachiocephalic artery (BCA) was then cannulated using a Gore-Tex tube, and accomplished bicaval venous cannulation. On initiating cardiopulmonary bypass (CPB), core cooling was commenced. We tightened the clamps on the pulmonary arteries to maximize body perfusion via the ductus arteriosus, while continuing the preparatory dissection as necessary. When the rectal temperature reached 28°C, circulatory arrest in the lower part of the body was begun by clamping the BCA at its origin. The CPB flow rate was lowered to 25–35mL/Kg/min to ensure continuous ACP via the BCA. We clamped the left subclavian artery and left common carotid artery to optimize intracerebral perfusion pressure. At that point, our target was a right radial artery blood pressure of >50mmHg, and a bilateral near-infrared spectroscopy value of >50%. Anesthesia was induced using an intravenous midazolam injection, with electrolyte and acid-base balances managed using the alpha-stat approach. We first clamped the descending aorta followed by the ascending aorta. At that point, we perfused the coronary arteries with blood at 32°C with a rate of 150ml/m2/min. We divided the ascending aorta just prior to the BCA’s origin, then ligated and divided the ductus arteriosus, resecting as much ductal tissue as possible. The hypoplastic aortic arch was longitudinally opened, and all four ends exposed. Next, we enlarged the arch using the autologous pericardial patch as an aortic tube according to z-score normal size. Then, we performed end-to-end anastomosis on the descending aorta to restore the continuity of the arch and descending aorta. The heart had thus far been kept beating during the procedure. At this point, we induced cardioplegia using a potassium-enriched solution to arrest the heart. Next, we removed the clamp from the ascending aorta, re-established the continuity of the ascending aorta to aortic arch and respecting its good concavity shape. We then provoked retrograde purging of the aorta and we gradually increased the CPB flow rate, removing the clamp from the BCA. The CPB was then resumed, with the flow rate calculated to ensure systemic patient perfusion. Before proceeding to rewarming, we carefully checked for any hemorrhaging. Next, we performed a possible additional repair during the rewarming period, such as VSD closure. We weaned the CPB when the rectal temperature reached 36.5°C. We administered hemostatic products to ensure good hemostasis. The sternum was initially left open if necessary. Nowadays, sternum is usually closed immediately