Predictors of increased postoperative length of stay after complete atrioventricular canal repair

The optimal timing of surgical repair for infants with complete atrioventricular canal defect remains controversial, as there are risks to both early and late repair. We address this debate by investigating the association of various risk factors, including age and weight at surgery, markers of failure to thrive, and pulmonary vascular disease, with postoperative length of stay following complete atrioventricular canal repair. Infants who underwent repair of complete atrioventricular canal were identified from our institutional Society of Thoracic Surgeons Congenital Heart Surgery Database. Additional clinical data were collected from the electronic medical record. Descriptive statistics were computed. Associations between postoperative length of stay and covariates of interest were evaluated using linear regression with bootstrap aggregation. From 2001 to 2020, 150 infants underwent isolated complete atrioventricular canal repair at our institution. Pre-operative failure to thrive and evidence of pulmonary disease were common. Surgical mortality was 2%. In univariable analysis, neither weight nor age at surgery were associated with mortality, postoperative length of stay, duration of mechanical ventilation, or post-operative severe valvular regurgitation. In multivariable analysis of demographic and preoperative clinical factors using bootstrap aggregation, increased postoperative length of stay was only significantly associated with previous pulmonary artery banding (33.9 day increase, p = 0.03) and preoperative use of supplemental oxygen (19.9 day increase, p = 0.03). Our analysis shows that previous pulmonary artery banding and preoperative use of supplemental oxygen were associated with increased postoperative length of stay after complete atrioventricular canal repair, whereas age and weight were not. These findings suggest operation prior to the onset of pulmonary involvement may be more important than reaching age or weight thresholds.