The physiology of the bidirectional cavopulmonary connection.

This article reviews the indications for the bidirectional cavopulmonary connection and demonstrates its efficacy in reducing mortality for the Fontan procedure. The indications for adding an additional source of pulmonary blood flow to the bidirectional cavopulmonary connection are discussed, but this issue remains controversial. Also unclear is whether the bidirectional cavopulmonary connection promotes symmetric growth of the pulmonary arteries, or whether growth of the left pulmonary artery is disadvantaged. Finally, systemic venous collateralization is a well-recognized sequel after cavopulmonary connection. The clinical implications of this collateralization are reviewed.