Single-ventricle palliation in children with atrioventricular septal defect and transposition of the great arteries: 45 years of experience

Abstract

Background: The association of atrioventricular septal defect and transposition of the great arteries is very rare. As a rule, these patients have unbalanced ventricles. However, there have been no studies describing the results of single-ventricle palliation in these children. Methods: All children who underwent surgery with a diagnosis of atrioventricular septal defect and transposition of the great arteries were included in the study. Data were obtained from medical records. Results: A total of 38 patients with atrioventricular septal defect and transposition of the great arteries underwent single-ventricle palliation at the study institution between 1971 and 2016. The mean follow-up was 12.4 years (median: 14.6 years, range 2–43.3 years). Most children had unbalanced atrioventricular septal defect (94.7%, 36/38). Survival was 67.6% (95% confidence interval [CI]: 50.0–80.2%) at 10 years and 57.8% (95% CI: 38.0–73.4%) at 20 years. By 10 years, 58.6% (95% CI: 40.8–72.7%) had progressed to Fontan completion, while 32.5% (95% CI: 18.2–47.6%) had died. In patients achieving Fontan completion, 20-year event-free survival was 73.3% (95% CI: 34.8–91.3%), while 5.0% (95% CI: 0.4–20.5%) had undergone cardiac transplantation and 21.7% (95% CI: 3.2–50.8%) had undergone takedown of the Fontan circulation. Freedom from atrioventricular valve surgery was 57.0% (95% CI: 37.2–72.7%) at 10 and 20 years. Conclusions: The association of atrioventricular septal defect and transposition of the great arteries is very rare, and most of these children have unbalanced ventricles. Single-ventricle palliation results in 25-year overall survival of 50%. However, in patients, who had Fontan completion, survival was 75% at 25 years after Fontan operation.

National outcomes of the Fontan operation with endocardial cushion defect

“…This combination of TGA and ECD is generally associated ventricular hypoplasia (95% of cases). 3 In our cohort, 42% patients with ECD had TGA/DORV. Also, ECD with conotruncal anomaly even in absence of ventricular hypoplasia may need single ventricle palliation when the relation of the ventricular septal defect to the outflow tracts is unfavorable for a biventricular repair.…”

“…While there is no direct information of the type of ventricular hypoplasia in our study, an associated diagnosis of HLHS in the ECD group (17%, 62/360 patients) in our study cohort indirectly suggests that left ventricular hypoplasia was at-least present seen in 17% of these patients undergoing a FO and is in agreement with prior studies. [7][8][9] Second, ECD can occur with conotruncal anomalies such as transposition of great arteries (TGA) 3 and DORV. This combination of TGA and ECD is generally associated ventricular hypoplasia (95% of cases).…”

“…Second, ECD can occur with conotruncal anomalies such as transposition of great arteries (TGA) 3 and DORV. This combination of TGA and ECD is generally associated ventricular hypoplasia (95% of cases) 3 . In our cohort, 42% patients with ECD had TGA/DORV.…”

“…The defects are either of an incomplete type (ostium primum atrial septal defect and transitional atrioventricular defect) or a complete atrioventricular canal defect type. While a biventricular repair is always desirable by septating at the atrial and ventricular level where appropriate, this is always not possible when there is ventricular hypoplasia, straddling of the AV valves, and complex associated conotruncal anomalies preventing septation at the ventricular level 2–4 . These patients will require a single ventricle palliation ultimately leading to a Fontan operation (FO).…”

“…While a biventricular repair is always desirable by septating at the atrial and ventricular level where appropriate, this is always not possible when there is ventricular hypoplasia, straddling of the AV valves, and complex associated conotruncal anomalies preventing septation at the ventricular level. [2][3][4] These patients will require a single ventricle palliation ultimately leading to a Fontan operation (FO). The traditional outcomes of the FO in these patients have been suboptimal due to abnormalities in the atrioventricular valves, presence of associated syndromes such as Down syndrome and Heterotaxy syndrome (HS).…”