PT - JOURNAL ARTICLE AU - Elaine V Robertson AU - Mohammad H Derakhshan AU - Angela A Wirz AU - David R Mitchell AU - James J Going AU - Andrew W Kelman AU - Stuart A Ballantyne AU - Kenneth E L McColl TI - Hiatus hernia in healthy volunteers is associated with intrasphincteric reflux and cardiac mucosal lengthening without traditional reflux AID - 10.1136/gutjnl-2016-311553 DP - 2017 Jul 01 TA - Gut PG - 1208--1215 VI - 66 IP - 7 4099 - http://gut.bmj.com/content/66/7/1208.short 4100 - http://gut.bmj.com/content/66/7/1208.full SO - Gut2017 Jul 01; 66 AB - Background and aims Hiatus hernia (HH) is a key mediator of gastro-oesophageal reflux disease but little is known about its significance in the general population. We studied the structure and function of the gastro-oesophageal junction in healthy volunteers with and without HH.Methods We compared 15 volunteers with HH, detected by endoscopy or MRI scan, but without gastro-oesophageal reflux disease with 15 controls matched for age, gender and body weight. Jumbo biopsies were taken across the squamocolumnar junction (SCJ). High-resolution pH metry (12 sensors) and manometry (36 sensors) were performed upright and supine, before and after a meal. The SCJ was marked with an endoscopically placed clip and visualised fluoroscopically.Results Cardiac mucosa was longer in volunteers with HH (3.5 vs 2.5 mm, p=0.01). There was no excessive acid reflux 5 cm above the upper border of the lower oesophageal sphincter (LOS) in either group but those with HH had short segment reflux 11 mm above the pH transition point after the meal when supine (pH<4 for 5.5% vs 0.3% of time, p=0.01). The SCJ and pH transition point were proximally displaced within the gastro-oesophageal junction in those with HH versus controls (p<0.05). The pH transition point was proximal to the peak LOS pressure point in HH subjects but distal to it in controls after the meal (p<0.05). When supine, the postprandial pH transition point crossed the SCJ in those with HH (p=0.03).Conclusions Healthy volunteers with HH have increased intrasphincteric reflux and lengthening of cardiac mucosa in the absence of traditional transsphincteric reflux.