Fibrous bands in conducting pulmonary arteries.

Fibrous bands have been described in the elastic (conducting) pulmonary arteries in 38 cases at necropsy, which represents a necropsy incidence of 14.4%. The fibrous bands are considered to represent one of the end results of episodes of pulmonary embolism. The formation of the bands is described and their significance is discussed in relation to their haemodynamic effects. Most of these bands are the result of clinically silent emboli.