Stage I Modified Norwood Procedure

Abstract

Two approaches can be taken in the Stage I modified Norwood procedure: (1) For an extremely hyperplastic ascending aorta, its diameter is only 2–3 mm, that is, much smaller than the aortic sinus. The classic Norwood ascending aorta formation method is likely to cause sinotubular junction stenosis, resulting in poor coronary artery perfusion. Using the modified approach, the ascending aorta, which has developed extremely poorly, is transversely divided at its junction with the aortic arch and directly end-to-side anastomosed to the neoaorta. (2) The innominate to pulmonary arterial shunt (Blalock–Taussig shunt) is replaced by a right ventricle to pulmonary arterial shunt (Sano Shunt). It offers the advantage of avoiding diastolic “stolen blood” from the ascending aorta of the Blalock–Taussig shunt to ensure that the new ascending aorta fills in diastole, which is conducive to coronary perfusion and cardiac function recovery. The disadvantage of this shunt is that a right ventricular incision may damage ventricular contractile function. A Gore-Tex artificial blood vessel with a diameter of about 5–6 mm may be selected to connect the pulmonary artery and the right ventricle; other artificial materials or allogeneic blood vessels are also available and can be placed on either side of the neoaorta.