A new model of tracheal stenosis in dogs using combined bronchoscopic electrocautery and ethanol injection.

PURPOSE: To establish a new animal model of tracheal stenosis in dogs that involves combined bronchoscopic electrocautery and ethanol injection.

MATERIALS AND

METHODS

Ten mongrel dogs were included in the study. With flexible bronchoscopic and fluoroscopic guidance, a combination of electrocautery (30 W) and ethanol injection (total volume 2 mL) was circumferentially applied to the trachea at the third thoracic vertebra level. Dogs were euthanized 4 weeks later and the stenosis diameter and histologic findings were evaluated.

RESULTS

All procedures were successful. Eight of the 10 dogs survived to 4 weeks, whereas two died from respiratory failure before the planned endpoint. For the eight full-term dogs, the mean percentage diameter stenosis (+/-SD) was 70.8%+/-9.3%, with a range of 56%-81%. Microscopic analysis showed that the maximum tracheal wall thickness was 2.48 mm+/-0.77. The degree of inflammatory cell infiltration varied, but cartilage destruction and mucosal ulceration were evident in all cases.

CONCLUSIONS

A new tracheal stenosis model was developed in dogs with use of combined bronchoscopic electrocautery and ethanol injection. This animal model is a technically simple, reliable, and tracheotomy-free model for the creation of tracheal stenosis.