PATHOPHYSIOLOGIC BASIS FOR OPERATION ON ZENKERS DIVERTICULUM

An increased resistance to bolus flow through the upper esophageal sph incter has in the past been considered the main cause of increased pha ryngeal contraction and the subsequent development of Zenker's diverti culum (ZD). Our study was designed to elucidate the pathophysiologic c haracteristics of the swallowing mechanism and its possible role in th e development of ZD. Fourteen patients with radiologically proved ZD a nd a matched control group of healthy volunteers with no gastrointesti nal symptoms were investigated with esophageal manometry using the sta tion pull-through technique. Although the mean amplitude of pharyngeal contraction was higher in the ZD group, there was no difference in th e duration of contraction. The resting tone of the upper esophageal sp hincter zone in patients with ZD was found to be lower than normal, bu t the closing pressure was higher and its duration longer. Though pres ent in 2 patients, pharyngosphincteric incoordination was not the main feature in the ZD group. Sphincteroesophageal incoordination was note d in 9 patients, however. The mean amplitude of the upper esophageal c ontraction was higher and the duration longer in the ZD group. There w as no upper esophageal peristalsis in 3 patients. An operation for the repair of ZD should therefore be undertaken only after careful interp retation of the manometric features of each patient.