Progressive pulmonary vascular disease after surgery in a case of patent ductus arteriosus with pulmonary hypertension.

In a 15-month-old girl with patent ductus arteriosus (PDA) with pulmonary hypertension, division of the PDA was undertaken, but she died of heart failure 7 months post-operatively. Morphometric study of biopsy and autopsy lungs showed that medial hypertrophy and pulmonary intimal lesions developed markedly after surgery. Severe pulmonary hypertension and hypoxemia were present preoperatively. The pulmonary hypertension remaining postoperatively and aggravated pulmonary hypoxemia are thought to have caused postoperative constriction of the pulmonary vessels and to bring about unusual medial hypertrophy. Since it is known that marked hypertrophy of the media can easily cause vasospasms, it is thought that, in the present case, the smooth muscle cells of the media became necrotic, which brought about damage to endothelial cells. Such damage, in turn, led to the development of occlusive pulmonary vascular disease.