Doesmeasurement ofyield pressure atthecardia during endoscopy provide information onthefunction ofthelower oesophageal sphincter mechanism

SUMMARYWe describe atechnique formeasuring theyield pressure atthecardia during upper gastrointestinal endoscopy. Thetest wasapplied to47patients withmacroscopic oesophagitis and nine patients withachalasia. Controls were123patients fromtheroutine endoscopy list inwhomno abnormality wasfound and21healthy volunteers. Yield pressure wassimilar inbothcontrol groups, butwassignificantly higher inachalasia (pendoscopy provides information whichmayreflect thefunction ofthewhole antireflux mechanism, andnotjust thelower oesophageal sphincter.