Evaluation of the lung function test in reversible glottis-dilating operations.

Our aim was to obtain an objective evaluation of the airway before and after reversible glottis-dilating operations using the lung function test. Bilateral abductor vocal cord paralysis remains mostly a complication of thyroid surgery. After thyroid surgery, the paralysis is potentially reversible, and the patient has a chance for recovery mostly in the first 6 months. According to these considerations, a reversible vocal cord laterofixation procedure was used instead of tracheostomy. The operations were performed endoscopically using high-frequency JET ventilation and the special endo-extralaryngeal suture technique by Lichtenberger. This technique was used in 92 cases. The pre- and postoperative data of reversible glottis-dilating techniques could be compared in 23 non-selected patients. Lung function tests that were performed were forced inspiratory volume (FIV1), forced expiratory volume (FEV1), peak inspiratory flow rate (PIF), peak expiratory flow rate (PEF) and resistance of the airways (Raw). For the evaluation of the functional results, we used the body-pletysmograph. Our aim was to obtain a quantitative evaluation of the results. These values allow us to compare the results achieved by using different glottis-dilating methods. The FEV1 (forced expiratory volume) improved 25%, and the FIV1 (forced inspiratory volume) improved 39% after the operations on average. PEF (peak expiratory flow rate) and PIF (peak inspiratory flow rate) improved 37 and 45% after glottis-dilating surgery on average. The Raw (resistence of airways) was 271.5% on average before the operations, and after reversible glottis-dilating operations decreased to a level of 200.6%.