Radiologic demonstration of anomalous pulmonary venous connection and its clinical significance

1. As surgical techniques continue to improve, early diagnosis and early surgical intervention of APVCs become increasingly important. 2. For a thorough understanding of APVCs, normal development of the pulmonary veins and the embryological basis of these anomalies are briefly reviewed. 3. Radiologic signs and clinical implications of varying types of APVCs are illustrated. 4. TAPVCs are less frequent, but clinically more significant, than PAPVCs. 5. The symptomatology of TAPVC is directly related to (1) the degree of pulmonary venous obstruction, (2) the severity of CHF secondary to volume overload, and (3) the magnitude of pulmonary hypertension. Patients with PAPVC become symptomatic only when the left to right shunt is greater than 50%9 6. TAPVC to the LVV produces a pretracheal density on the lateral view prior to the appearance of snowman configuration on the postero-anterior view. TAPVC to the PV shows a combination of severe pulmonary edema and a normal-sized heart. 7. PAPVC may be diagnosed by visualization of the anomalous vein(s) in addition to the usual signs of an ASD (increased pulmonary blood flow plus right-sided cardiomegaly). 8. PAPVC is usually associated with an ASD. Scimitar syndrome is an exception to the rule. 9. The surgical repair of TAPV without obstruction is generally relatively simple because of the strong tendency for all of the pulmonary veins to converage into a common chamger. Emergency operation is the only hope for patients with TAPVC with obstruction. 10. The surgical treatment of PAPVC consists of reconstruction of the atrial septum; thus, the anomalous veins can be diverted into the left atrium. 11. Surgical correction of PAPVC prevents detrimental resection of the lung with normal pulmonary venous connection.