Method for fabrication of tracheal cannula, surgical procedure involved in its fixation and the post operative care of the animal were studied in an experiment on sheep. Two types of polyethylene tracheal cannula viz., ‘T’ and ‘L’ shaped were fabricated and surgically fitted in the trachea of sheep. The animal fitted with tracheal ‘T’ died after 2 days after surgery due to callous formation. Allowing air passage through cannula, restricting nasopharyngeal ventilation due to placement of one way air valve in the trachea resulted in drying of the tracheal seromucoid exudate due to prevailing high ambient temperature (40–42°C) and lower R.H. (23%). To avoid callous formation and to allow normal nasopharyngeal respiration a ‘L’ shaped cannula was fabricated and surgically fitted in trachea. Blocking nasopharyngeal end of the cannula by inflated balloon allowed normal breathing through cannula. Subsequently 5 animals were fitted with tracheal ‘L’ and all the animals recouped from the surgery.
