Transcaval repair of sinus venosus defect. Using a butterfly-shaped patch.

We describe an operative technique used in 30 patients from 1982 to 1995, in which sinus venosus atrial septal defect with anomalous pulmonary venous connection is repaired through longitudinal incision confined to the vena cava. A single oval patch is folded like the wings of a butterfly: the posterior wing is used to separate superior vena caval and pulmonary venous blood, and the anterior wing is used to enlarge the terminal cava. This approach avoids both sinus node dysfunction and superior vena caval or pulmonary venous obstruction. Operative findings suggest that the sinus venosus defect is a malformation involving abnormal confluence of sinus venosus, anomalous right superior pulmonary, and right common cardinal veins. Further, the sinus venosus contributes more to the formation of the right atrium, displacing the crista terminalis downward and forward and separating the atrial component of the right atrium from the terminal cava.