It is unusual for a single anomalous pulmonary venous connection from only one pulmonary lobe to result in a sufficient volume load to justify sur- gical repair. However, if there is >1 anomalous vein and a moderate or large left-to-right shunt, then surgical repair is associated with a reduction in RV size and PA pressure and can be useful.S4.1.2-5 7. Surgical repair of a scimitar vein includes direct reimplantation of the scimitar vein into the left atrium, side-to-side anastomosis of the scimitar vein to the left atrium and closure of its connec- tion to the inferior vena cava or intracaval baff- ling. This surgery can be technically challenging with a greater risk of postoperative vein throm- bosis than is associated with simpler anomalous pulmonary vein abnormalities.S4.1.2-10 4.1.3. Ventricular Septal Defect Recommendations for Ventricular Septal Defect Referenced studies that support recommendations are summarized in Online Data Supplement 28. 