DYSPHAGIA AFTER PHARYNGOLARYNGEAL CANCER-SURGERY .1. PATHOPHYSIOLOGY OF POSTSURGICAL DEGLUTITION

Eighty-one patients were examined after laryngopharyngeal cancer surge ry with a sequential computer manometry system using 4-channel-pressur e probes, The general swallowing coordination is neither a matter of t he oropharyngeal pressure thrust nor of the pharyngeal transit time, b ut mainly depends on swallowing initiation. The points of interest are both the pharyngeal inlet and outlet. The topographic correlates are the base of the tongue and the upper esophageal sphincter (UES). Resec tions of the base of the tongue lead to a decrease of volume available for pressure generation, thus reducing the tongue driving force. The swallowing reflex is uncoordinated resulting in dyskinesia of the UES. Compensation may be achieved with a stronger oropharyngeal thrust and /or repeated swallows. Distal resections alter the pharyngoesophageal segment so that a functional obstruction results, combined with lower pressure amplitudes in the hypopharynx, reducing the pressure gradient necessary for bolus flow. This increasing resistance can be overcome by higher propulsive forces in the base of the tongue region. In case of additional lingual defects, deglutition is subject to decompensatio n, highlighting the major role of the tongue as a pressure generator f or bolus passage.