Functional diagnosis in surgery of the large airways

The main indications for surgery of the airways are (1) non-tumorous airway stenosis and (2) tumors of the large airways with and without relevant stenoses. The aim of the following study was to find out which degree of stenosis is an absolute indication for resection and to what extent the functional disturbances are reversible following surgery. We investigated various groups of patients (stenosis of the trachea, lobectomy with sleeve resection, extended pneumectomy with resection of the distal trachea, pneumectomy with resection of the bifurcation, resection of the main bronchus and lobectomy, rupture of the main bronchus) from 1978 to 1982, before and up to 3 years after surgery. Body-plethysmography (one second forced expiratory volume = FEV1; one second forced inspiratory volume = FIV1; Residual volume = RV; total lung capacity = TLC; airway resistance = Raw; specific airway conductance = sGaw), flow volume relation measurements (maximal inspiratory flow = Vmax insp; maximal expiratory flow = Vmax exp; and flow at various lung volumes), blood gas analysis and an endoscopic estimation of the tracheal diameter were performed. Tracheal resection with end-to-end anastomosis in patients with non-tumerous tracheal stenosis improved the tracheal diameter from 6.0 to 11.7 mm, the sGaw from 0.04 to 0.08 (cmH2O s)-1 and the severity of dyspnea significantly. There was no measurable change in airway caliber following administration of beta 2-adrenergics. The most sensitive parameters for describing the tracheal stenosis are the resistance and flow volume values. A tracheal diameter smaller than 6.5 mm corresponding to a sGaw smaller than 0.03 (cmH2O s)-1 procedured severe dyspnea, which is incompatibly with normal life.(ABSTRACT TRUNCATED AT 250 WORDS)