Respiratory mucosal damage after brush biopsy--an experimental study in rabbits

Bronchial brushing is one of the main methods of obtaining bronchial mucosal material for cytologic examination. In 37 rabbits, the tracheal respiratory mucosa, brush biopsy damage and post-biopsy wound-healing were studied. In the majority of animals, the brush had penetrated the basement membrane but in animals with undamaged basement membrane there was, within one to two days, a covering cell layer, probably regenerated from the intact epithelium and from basal cells. Deep, wound areas were covered during the first two to three days after damage by granulation tissue protruding into the tracheal lumen. After rejection of the granulation tissue, ulceration was covered by epithelium within three days and a normal ciliated epithelium restored within three weeks.