Lung biopsy with frozen section as a diagnostic aid in patients with congenital heart defects.

In eight patients with congenital heart defects and equivocal preoperative hemodynamic data, lung biopsy with frozen section was performed and quantitative morphometric analysis carried out to help select a palliative or corrective surgical procedure. During catheterization it had been possible in only six of the eight patients to enter the pulmonary artery and obtain pressure measurements; four patients had moderate to severe elevation of pulmonary vascular resistance whereas the other two had only mild elevation of pulmonary arterial pressure, but they were being considered for a Fontan procedure. The lung biopsy tissue was taken inflated and fixed inflated in hot glutaraldehyde. From cryostat sections arterial concentration was assessed relative to alveolar concentration, and the degree of arterial muscularity was assessed by wall thickness and extension of muscle; the more advanced Health-Edwards arterial changes were also evaluated. On the basis of the morphologic assessment, six of the eight patients underwent corrective surgery and two underwent a palliative procedure. Postoperative hemodynamic data available in four of the patients who underwent corrective surgery revealed either a significant reduction in pulmonary vascular resistance or return to a normal level of pulmonary arterial pressure, whereas no change has occurred in the one patient studied who underwent a palliative procedure. Assessment of pulmonary arterial development and structure on lung biopsy with frozen section proved helpful in deciding between a palliative and corrective surgical procedure.