Surgical management of atrio ventricular septal defects with normal caryotype

Atrio ventricular septal defects (AVSD) with normal caryotype represent in average 25% of AVSD. They constitute a more complex group of patients characterized by frequent left sided heart obstructive lesions, raising the problem of the appropriate indications between biventricular and univentricular procedures.

Sixty-nine consecutive patients, who had AVSD with normal caryotype underwent surgery. According to the anatomical complexity there were 22 intermediate AVSD, 36 complete AVSD and 11 complex AVSD. Associated lesions were present in 68% of the patients including left sided heart anomalies in 57%. According to the size of the left ventricle (LV) evaluated on the LV/RV end diastolic diameter ratio calculated at 2D echocardiogram: right ventricular (RV) dominance was found in 29%; with border line LV in 13 patients and truly hypoplastic LV in 7 patients. Biventricular repair was always favored in case of border line LV and precluded when the LV/RV ratio was less than 0.33.

There were 57 biventricular repairs with 10 years actuarial survival of 70 +/- 8% and respectively, 100% in the complex AVSD, 86% in the intermediate AVSD and 51% in the complete AVSD (P = 0.006). The risk factors for biventricular repair were the association to a subaortic stenosis (P = 0.01) and the severity of the mitral valve lesions (P = 0.03) that led to 38% reoperation. There were 12 univentricular palliation with 10 years survival of 66 +/- 14%. The risk factor for univentricular palliation was the association to a severe pre-operative mitral regurgitation (P = 0.005).

Biventricular repair should be precluded in patients presenting with subaortic stenosis. Severe mitral valve anomalies lead to elevated mortality and morbidity with frequent reoperations. Univentricular repair might have larger indications and cardiac transplantation might be considered in patients with truly hypoplastic LV presenting with severe pre-operative AV valve regurgitation.