Biventricular repair in children with complete atrioventricular septal defect and a small left ventricle

Biventricular repair of complete atrioventricular septal defect (CAVSD) with small left ventricle aims to restore the normal loading conditions of the left ventricle. This report retrospectively evaluates the outcome of biventricular repair in 19 children with CAVSD and a small left ventricle.

Our computer database was searched for all patients with CAVSD operated on between January 1988 and December 2005. Patients who underwent biventricular repair of CAVSD were considered for investigation if they had a preoperative left ventricle-to-right ventricle long axis ratio (LAR) of <1.1 as determined by cardiac catheterization.

There were 259 patients who underwent surgical correction of complete atrioventricular septal defect. Nineteen (10.3%) of 184 patients who underwent biventricular repair had small left ventricle based on LAR measurements. These children had no other associated congenital heart anomalies and had no previous surgery. Nine of these children had associated Trisomy 21. There were 10 (52.6%) males and 9 (47.4%) females, with age of 1-210 (122+/-67) days and weight of 2.5-9.0 (5.26+/-1.7) kg at surgery. Mean LAR was 0.76+/-0.14. Two patients (10.5%) died on the 8th and 11th postoperative day, respectively. Both had very small left ventricle (LAR of 0.45 and 0.60, respectively) and received ECMO support for postoperative low output syndrome and intractable pulmonary hypertension. A patient with an LAR of 0.62 who had ECMO support for postoperative myocardial failure underwent successful heart transplantation on the 21st postoperative day. The long-term survivors (89.5%) with LAR>0.65 had an uncomplicated postoperative course, had undergone regular follow-up (65+/-36 months) with echocardiographic assessment of the left ventricle, and had good left ventricular function. There was no early reoperation for residual ventricular septal defect, left AV valve regurgitation, or left ventricular outflow tract obstruction. Late reoperation was performed in three patients (17.4%) who underwent mitral valve repair for significant regurgitation in the 18th, 59th, and 87th month postoperatively.

Biventricular repair of CAVSD with small left ventricle in infants and children whose LAR is >0.65, although not without risks, improve patients' functional and clinical status even in long-term follow-up. Particular caution should be taken in patients with LAR of <0.65, since these are patients who may not be amenable to biventricular repair, but for whom univentricular palliation may be more suitable.