Pulmonary vascular disease in total anomalous pulmonary venous drainage.

Pulmonary vascular disease (PVD) was assessed by a qualitative and quantitative histopathologic analysis of lung specimens of 40 patients (age at autopsy 5 days to 12 years, median 3 months) with total anomalous pulmonary venous drainage. A PVD index was derived by counting the number of vessels with each Heath-Edwards grade of PVD (PVD index = [0 (Normal) +1 (N grade 1) +2 (N grade 2)....+6 (N grade 6)]/number of vessels graded, where N = the number of patients) in randomly selected pulmonary resistance vessels 30-300 mu in diameter. Patients with pulmonary venous obstruction died earlier and had a higher PVD index as a group than patients with unobstructed venous drainage. A remarkable degree of advanced pulmonary vascular changes was found in the entire group, even young infants. Pulmonary vascular obstructive disease is an important factor in the pathophysiology of this lesion. Careful attention to the prevention and management of increased pulmonary vascular resistance in the postoperative period may improve survival.