The effect of tracheostomy on posterior cricoarytenoid muscle

It has been reported previously that the amount of electromyographic (EMG) potential of the posterior cricoarytenoid (PCA) decreases after prolonged tracheostomy. It is, therefore, reasonable to assume that a significant alteration of the biochemical characteristics of this muscle would also occur. In addition to histochemical analysis, endoscopic and EMG data were recorded to give a direct comparison in each subject. Seven male beagles were used for this study. Four were trnchcostomized and three served as controls. They were examined immediately before and after surgery and again after 4 weeks by EMG and endoscopic techniques. Histochemical staining was performed on each subject. All three modalities failed to demonstrate a substantial difference between the controls and the experimental dogs.