Abstract 14058: Intramural Ventricular Septal Defects After Repair of Conotruncal Anomalies Are Associated With Postoperative Morbidity

Abstract

Introduction: Intramural ventricular septal defects (VSDs) are tunnel-like communications between a great artery and right ventricular free wall trabeculations that can occur after repair of conotruncal anomalies. We sought to assess the prevalence of residual intramural VSDs and their impact on postoperative course. Methods: We reviewed all patients at our institution who underwent biventricular repair of a conotruncal anomaly involving VSD baffle to a great artery from the left ventricle from 1/1/11 to 6/30/13. Perioperative echocardiographic images were reviewed for residual intramural or non-intramural VSDs. The primary outcome was a composite of ECMO use, cardiac transplantation, or mortality. Secondary outcomes included hospital length of stay (LOS) and need for repeat catheter-based or surgical VSD closure. Results: Of 158 total subjects, 92 (58%) were male and diagnoses were tetralogy of Fallot (n=111), d-transposition of the great arteries (14), truncus arteriosus (13) and other (20). Median age at surgery was 51 days (IQR 6,107). Residual VSD was present in 111 subjects; 29 (26%) had an intramural defect, and 82 (74%) had non-intramural defects (71 peripatch defects, 6 small muscular defects, and 5 with both). Of the non-intramural VSDs, 79 (96%) were hemodynamically insignificant lesions (<2mm). Residual intramural VSDs were more likely than non-intramural VSDs to be greater than 2mm (48% vs 4%, p<0.001). There was no difference in weight, age at operation, or type of conotruncal anomaly based on type of residual VSD. The primary composite outcome was more prevalent in subjects with residual intramural defects compared to non-intramural defects (5/29 [17%] vs 4/82 [5%], p = 0.05). In addition, subjects with residual intramural VSDs had longer LOS (24 days [IQR 13,67] vs 11 days [IQR 5,23], p=0.002). The rates of repeat catheter-based or surgical closure were low overall but higher in subjects with intramural VSDs (8/29 [28%] vs 5/82 [6%], p=0.005). Conclusions: Intramural VSDs are common after repair of conotruncal anomalies and tend to be larger than non-intramural VSDs. Although most subjects still have favorable outcome, intramural VSDs are associated with greater postoperative morbidity, longer LOS, and need for reintervention.