Repair of complete atrioventricular septal defects in patients weighing less than 5 kg.

BACKGROUND: The aim of this study was to evaluate the impact of weight less than 5 kg at operation on mortality and morbidity in patients with atrioventricular septal defect (AVSDc) undergoing total correction.

METHODS: Between January 1990 and December 2002, 190 consecutive patients with AVSDc underwent total biventricular correction. They were divided into two groups: group I (n = 64 patients weighing < 5 kg) and group II (n = 126 patients weighing > 5 kg). Associated major cardiac malformations were found in 49 (25.8%) patients. Associated left atrioventricular valve (LAVV) malformations were found in 35 (18.4%) patients. The mean follow-up time was 4.1 +/- 2.9 years (range 2 months-10.7 years).

RESULTS: The in-hospital mortality in group I was 7.8% (5 patients) versus 8.7% (11 patients) in group II (p = 0.95). Major associated cardiac malformations (p < 0.001) and pulmonary hypertension (p = 0.006) were found to be strong predictors for poor postoperative survival. At discharge the mean LAVVR grade in group I was 1.45 +/- 1.2 versus 1.2 +/- 1 in group II (p = 0.13). The actuarial overall survival rates at 1, 3, 5, and 7 years were 96.5%, 92.5%, 91.5%, and 89% respectively and the actuarial overall reoperation free survival rates at 1, 3, 5, and 7 years were 95%, 87%, 84%, and 73%. Twenty-three patients underwent reoperation due to severe left atrioventricular valve regurgitation (LAVVR). Strong predictors for overall reoperation free survival were the operation year before 1995 (p < 0.001), postoperative LAVVR greater than or equal to 2 (p = 0.006), major associated cardiac malformations (p = 0.00034), associated LAVV malformations (p = 0.0044), and non or partial LAVV cleft closure (p = 0.012). The actuarial survival rates between patients weighing less than 5 kg versus patients weighing more than 5 kg were similar (p = 0.51); instead the overall reoperation free survival was significantly lower in patients weighing less than 5 kg (p = 0.022) according to the log-rank test. Weight less than 5 kg (p = 0.023, beta = -0.6) was one of the predictors for reoperation due to severe LAVVR in this series.

CONCLUSIONS: We may conclude that in the current era repair of AVSDc can be carried out successfully in patients less than 5 kg, however, weight less than 5 kg at initial complete repair seems to be a predictor for late reoperation due to LAVVR. Suture separation at the cleft site or between the leaflets of the newly created mitral valve and the patch remain the main causes of postoperative LAVVR in patients weighing less than 5 kg.