[Objective evaluation of respiratory function of the larynx after partial laryngectomy of various range]

The aim of the study was to identify factors and their effect on the respiratory efficiency of the larynx after partial laryngectomy. The material consisted of 72 patients aged 30 to 71 years (mean 54.3 years) who underwent partial laryngectomy due to cancer, and 10 healthy volunteers aged 22 to 29 years (mean 24.5 years). Airflow was measured under normal conditions and upon application of external resistance. Methods included history taking and physical examination, spirometry, laryngovideoscopy (Lvs), and computed tomography (CT) of the larynx. Some airflow parameters were decreased prior to surgery in comparison to predicted values. In a majority of patients, surgery had a negative effect on all parameters of airflow. Reduction was greater for inspiratory than expiratory parameters. Analysis of the shape of flow-volume loops in patients after surgery showed that the mixed type prevailed. This is characterized by reduction of the inspiratory and expiratory parameters, with greater effect on the inspiratory phase. Morphologically, the mixed type corresponds to narrowing of various extent with flaccid wall stenosis. The flow-volume shape changed dynamically during the healing process of the larynx until normalization was observed. This process was independent of the type of surgery but depended on the size of the laryngeal lumen and wall stiffness. Significant differences were found when laryngeal lumen was measured using CT or Lvs, with Lvs being more accurate. Lung volume parameters remained unchanged, but a statistically significant relationship with lumen size was observed both in experimental and clinical investigations. The most useful parameters for estimating laryngeal airflow were: PIF, FIF50, FIV1, FIV1%/N FEV1 and % Rz/N PEF. Upper and lower values were established for PIF (1.4-2.0 L/s), FIF50 (0.7-1.9 L/s), FIV1 (0.7-1.6 L), FIV1%/N FEV1 (40-60%),% Rz/N PEF (20-40%) on the basis of which the decision to restore respiration through the larynx (decannulation) may be made. It can be concluded from the results that spirometry and Lvs are more accurate than CT for assessment of the respiratory function of the larynx after partial laryngectomy.