MUCOCILIARY CLEARANCE FOLLOWING SEGMENTAL TRACHEAL REVERSAL

Ciliated tracheal epithelium is arranged in a polarized pattern orient ed according to the inferior-superior axis of the trachea and is respo nsible for the transport of mucus toward the larynx. In this study, ci liary beat orientation and the influence of external factors on mucoci liary clearance direction were studied in rabbit inverted cervical tra cheas. The animals displayed normal respiration postoperatively. After 16 weeks, airway clearance was studied by observation of the movement of silicone particles placed in the inverted segment and in normal pa rts of the ciliated epithelium. Cilia exhibited unidirectional and coo rdinated movement within inverted tracheal segments. As shown by the d irection of effective flow produced by beating cilia and by scanning e lectron microscopy, the cilia in the inverted segment beat in the oppo site direction from the cilia in the remainder of the trachea. This st udy demonstrated that ciliary orientation is irreversibly determined, but the reversal of ciliary beating within the cervical trachea had no adverse effects on the survival of the animals.