Factors associated with systemic to pulmonary arterial collateral flow in single ventricle patients with superior cavopulmonary connections.

OBJECTIVE: Systemic to pulmonary arterial collateral flow (CollF) is common in single ventricle patients with superior cavopulmonary connections (SCPC), although associations with CollF are not well understood. We previously described a method to quantify CollF by cardiac MRI (CMR). We sought to identify factors associated with CollF in a large cross section of patients with SCPC.

METHODS: A retrospective observational cohort study of events from birth to study CMR was performed for all patients with SCPC who had CollF quantified by CMR.

RESULTS: CollF was quantified in 96 patients at a median age of 2.6 (IQR 1.9-3.1) years and 2.1 (1.4-2.7) years after SCPC and measured 1.6±0.7 L/min/m(2) (33±11% of aortic flow and 48±16% of pulmonary venous flow). Significantly higher amounts of indices of CollF were associated with: duration of chest tubes (p≤0.05 for all), intensive care unit and hospital length of stay (p≤0.04 for all), higher O2 saturation at Stage 2 discharge (p=0.04 for CollF/aortic), female sex (p≤0.007 for CollF/aortic and CollF/pulmonary venous), and history of a Blalock-Taussig shunt (p<0.04 for CollF and CollF/aortic). Multivariable models were constructed to identify factors independently associated with CollF measures and included: female sex (p≤0.006 for all), O2 saturation at Stage 2 discharge (p=0.013 for CollF/aortic) and total chest tube days (p=0.001 for all). These models explained 20-22% of the variance in the outcomes.

CONCLUSIONS: These data support hypotheses that perioperative morbidity and pleural inflammation play a role in CollF development and that CollF affects pulmonary blood flow.