The cricothyroid muscle after cricothyroidotomy. A porcine experimental study.

Cricothyroidotomy in elective use or emergency situations has been discussed by several authors during recent years. The main complication reported has been subglottic stenosis. We have used this method for several years and among our patients there has been no case of stenosis. The major complication in our material has been voice dysfunction. Some of the patients had a change in voice quality consistent with dysfunction in the cricothyroid muscles (diminished voice range and a lowered pitch). The aim of this study was to investigate whether cricothyroidotomy and insertion of a tracheostomy tube caused physiological or morphological changes in the cricothyroid muscle, by direct injury or secondary to a peripheral nerve lesion. In the six animals that were cricothyroidotomized during 7-9 days and examined after 9-15 weeks, we found neither changes in the EMG nor in the muscle morphology indicating injury to the muscle or its peripheral nerve supply.