The ultrastructure of human male urethral stricture.

Biopsy material was examined from 20 urethral strictures at the time of urethroplasty, using ultramicroscopic methods not hitherto applied to the study of the pathogenesis of stricture. Abundant smooth muscle and elastic tissue was found in the post-inflammatory strictures. The scar tissue from post-traumatic strictures merely showed dense collagen. An anatomical basis for the well known difference between the fibrous and the resilent stricture is demonstrated, and the role of smooth muscle in the development and behaviour of strictures is discussed.