Abstract
Background It is common practice to interrupt all alternative sources of pulmonary blood flow (''competitive flow'') at the time of a bidirectional superior cavopulmonary anastomosis (BCPA), although the merits of this have not been systematically studied. Methods and Results We reviewed the early and medium-term clinical and hemodynamic findings in 108 consecutive patients 3 weeks to 25 years old (median, 1.9 years) undergoing BCPA at one of three institutions.
Preoperatively, pulmonary blood flow was dependent on antegrade ventricular flow (n=50), systemic-to-pulmonary shunts (n=33), or mixed sources (n=25). Postoperatively, competitive sources of pulmonary blood flow were left patent in 43 of 108 patients (40%).
There were four early (3.7%) and four late deaths, none related to persistence of competitive flow. After BCPA, patients with competitive how had significantly higher systemic oxygen saturations at 1 hour (85% versus 79%), 24 hours (84% versus 78%), and at hospital discharge (84% versus 78%) and required a shorter period of artificial ventilation (median, 9 versus 24 hours) and intensive care (median, 2 versus 4 days).
Oxygen saturations at late follow-up (median, 2.8 years; range, 1 to 7) did not differ (83% versus 82%). No patient developed pulmonary arteriovenous malformations.
Conclusions Competitive flow is well tolerated in the short and medium term after BCPA, and early postoperative systemic oxygen saturations are improved. The long-term influence of competitive flow on pulmonary arterial growth, arteriovenous malformation development, acid ventricular function warrants investigation.