Intermittent tracheostomy in sheep

A modified tracheostomy was designed for respiratory function studies in sheep. Our primary objective was to prevent development of severe tracheal stenosis, which was observed with procedures designed for canine tracheostomy. Surgery consisted of an intercartilaginous tracheal slit, with apposition of tracheal mucosa to skin. This procedure produced no significant stenosis at postmortem evaluation in 19 sheep. In contrast, 5 of 20 sheep with excision of the ventral 1/3 of the third and fourth tracheal rings, had severe tracheal stenosis.