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