INFLUENCE OF SURGERY ON DEGLUTITIVE UPPER ESOPHAGEAL SPHINCTER MECHANICS IN ZENKERS DIVERTICULUM

Background/Aims-To evaluate the role of upper oesophageal sphincter (U OS) compliance in dysphagia, the functional consequences of surgery we re evaluated in eight patients with pharyngeal diverticula. The study examined the hypotheses that hypopharyngeal intrabolus pressure is an indicator of UOS compliance and that UOS opening and intrabolus pressu re are normalised by surgery. Methods-In eight patients and nine healt hy controls, we measured the timing of swallow events, UOS relaxation, maximal UOS dimensions, intrabolus pressure, and trans-sphincteric bo lus flow rates by simultaneous videoradiography and pharyngeal manomet ry. Results-Bolus flow rates were not changed by surgery. Surgery sign ificantly increased UOS opening (p = 0 . 0001) and reduced hypopharyng eal intrabolus pressure (p = 0 . 0001). The slope of the relation betw een sphincter area and intrabolus pressure was steeper in patients tha n controls and was normalised by surgery. Surgery had minor effects on basal UOS tone and timing of swallow events. Conclusions-Upper oesoph ageal sphincter compliance is poor in Zenker's diverticulum and is nor malised by surgery. Hypopharyngeal intrabolus pressure, which correlat es with resistance to trans-sphincteric bolus flow, is a useful indica tor of UOS compliance. Intrabolus pressure may be a predictor of outco me after myotomy in pharyngeal dysphagia. Cricopharyngeal myotomy is a mandatory component of surgery for Zenker's diverticulum.