Systemic-to-pulmonary collaterals in pathological states: a review

Abnormal systemic-to-pulmonary-artery anastomoses can exist in many pathological conditions and result in a left-to-right shunt. Three such conditions are (a) congenital abnormalities, e.g., pulmonary vein atresia, (b) acquired states, e.g., chronic bronchiectasis, and (c) post-surgical states, e.g., a Mustard procedure for complete transposition. Regardless of the etiology, the anastomosis and resulting shunt produce increased oxygen saturation in the ipsilateral pulmonary artery. Four cases are presented, with emphasis on the angiographic and hemodynamic findings.