Repair of complete atrioventricular septal defects: Results with maintenance of the coronary sinus on the right atrial side

Background: This study was undertaken to determine that maintaining coronary sinus on the right atrial side during the surgical repair of complete atrioventricular septal defect (AVSD) does not increase the risk of postoperative complete heart block. Methods: This is a retrospective study of 51 consecutive patients who underwent biventricular repair of complete AVSD from September 2000 to January 2005. Electrocardiograms and operative data were analyzed. Results: The mean age was 13.3 months (4 to 60). In all the 51 patients, except 13 cases, repair was performed using the two-patch technique. All atrial septal defects were closed using the patch technique with the coronary sinus maintained on the right atrial side in 48 (94%) cases. The cleft in the neomitral valve was closed in all patients. Associated lesions were repaired in four patients (7.8%); coarctation of aorta in two patients; multiple ventricular septal defects (VSD) with coronary sinus type-total anomalous pulmonary venous drainage and right-sided diaphragmatic eventration in one patient; and tetralogy of Fallot in one patient. There were five deaths (9.8%) in a series. The mean hospital stay was 11.8 days. During the same hospitalization, reintervention was required in two cases: one for residual VSD and the other for a severely dysplastic regurgitant mitral valve. Mean follow-up was 11.3 months. One patient required reoperation for residual VSD, residual atrial septal defect, and moderate mitral regurgitation 5 months after the initial repair. Except for first-degree heart block documented in nine cases and right bundle branch block in two cases, all patients remained in sinus rhythm on follow-up electrocardiography as preoperatively documented. No patient required prolonged cardiac pacing in the postoperative period. Conclusion: We believe that maintenance of the coronary sinus on the right side can be safely accomplished in the majority of complete AVSD repair as long as careful attention is paid to the anatomy of the conduction system. This technique did not increase the risk of postoperative heart block and permanent pacemaker insertion was not required.