Norwood operation

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Norwood operation

The Norwood surgery is a three-step surgical procedure typically used in children with hypoplastic left heart syndrome or double inlet left ventricle. The starting point is a severe underdevelopment of the left heart with stenosis / occlusion of the aortic and / or mitral valve and the underdevelopment of the initial part of the aorta (the large body artery or main artery ) with aortic coarctation behind the aortic arch .

  • Norwood Stage 1 (In the first few days or weeks of life)
    The trunk of the pulmonary artery (the pulmonary trunk ) is severed from the heart. The ductus arteriosus (the prenatal connection between the aorta and the pulmonary artery) is severed. The atrophied aorta is cut open in the entire arch up to the coarctation of the aorta and widened with the help of a patch and connected at the root to the trunk of the pulmonary artery. In order to supply venous blood to the lungs for oxygenation, a shunt (plastic tube) is implanted between a branch of the aorta and the pulmonary artery ( Blalock-Taussig anastomosis ). After that, the blood flow to the pulmonary arteries and the main artery is ensured, but the children have cyanosis because arterial and venous blood mix.
  • Norwood stage 2 (about two to three months later)
    The superior vena cava is severed and connected to the pulmonary artery on both sides. The shunt between the aorta and the pulmonary artery is removed. A patch is sewn into the right atrium, which initially prevents the blood from the inferior vena cava from flowing into the lungs. This condition is also called Glenn's anastomosis or Hemi-Fontan . This operation relieves the pressure on the right ventricle of the heart, as the oxygen-poor blood flows from the upper half of the body directly into the lungs. Mixed blood no longer flows in the lungs and only part of the oxygen-poor blood from the lower half of the body mixes with the oxygen-rich blood from the lungs in the body's circulation.
  • Norwood stage 3 (about two to three years later, is handled differently in individual clinics)
    The patch in the area of ​​the atrium is removed and the inferior vena cava connected to the pulmonary artery. A new patch is sewn laterally into the wall of the atrium (intracardial shunt). In the sense of an overflow valve (if the lungs cannot take in all of the blood), a small hole is punched in the patch ( fenestration ). It either closes itself over time or is later closed with a small umbrella when the circulation is stable and it is hemodynamically effective. The circuits are now separated. Mixed blood no longer flows. The oxygen-poor blood flows directly into the pulmonary artery via the lower and upper vena cava. The oxygen-rich blood is pumped into the aorta from the right ventricle. This operation is also carried out (in individual clinics without the use of the heart-lung machine ) with an extracardiac shunt (half-shell on the antechamber). The term used frequently for this is TCPC = "Total cavo-pulmonary connection". Steps 2 and 3 correspond to Fontan's operation .