Drug locally used for tracheal stenosis is:

Mitomycin C is a mitomycin that is used as a chemotherapeutic agent by viue of its antitumour activity. It is given intravenously to treat upper gastro-intestinal cancers (e.g. esophageal carcinome), anal cancers, and breast, as well as by bladder instillation for superficial bladder tumors. It causes delayed bone marrow toxicity and therefore it is usually administered at 6-weekly intervals. Prolonged use may result in permanent bone-marrow damage. It may also cause lung fibrosis and renal damage. Mitomycin C is highly toxic drug used only in resistant cancers of stomach, cervix, colon, rectum, bladder, etc. It is transformed intracellularly to a form which acts as an alkylating agent and kills cells in G1-M phases. Bone marrow and g.i.t. are the primary targets of toxicity. ESSENTIALS OF MEDICAL PHARMACOLOGY, en.wikipedia.org K.D.TRIPATHI SIXTH EDITION PAGE NO:827