日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

The stage 1 Norwood procedure, using a modified Blalock–Taussig (BT) shunt under cardiopulmonary bypass has been the standard procedure for patients with hypoplastic left heart syndrome (HLHS), with Norwood et al. first reporting successful palliation in 1981. However, the surgical results were unsatisfactory in 1992. Of the patients with right atrial isomerism who underwent repair of total anomalous pulmonary venous connection under cardiopulmonary bypass in the neonatal or early infantile period, many patients with pulmonary atresia, who received a modified BT shunt had a poor clinical outcome due to unstable hemodynamics postoperatively. However, many patients with pulmonary stenosis or post pulmonary artery banding were relatively stable hemodynamically, and survived the procedure. We suggest that the decrease in diastolic blood pressure from blood steal by the BT shunt resulted in a decrease in coronary blood flow. The decrease in pulmonary vascular resistance in the early postoperative period reinforced the increased flow through the BT shunt and ameliorated unstable hemodynamics. We report a modified Norwood procedure using a conduit between the right ventricle and pulmonary artery (RV-PA Norwood procedure). This modification led to satisfactory results and stable postoperative hemodynamics with no operative deaths in seven consecutive patients with HLHS. This modification has now become an option for the stage 1 Norwood procedure. An early bidirectional Glenn procedure following the RV-PA Norwood procedure has markedly improved the prognosis of patients with HLHS.