Introduction Current data relating to esophageal motility evaluated by high resolution manometry(HRM) in presence of hiatal hernia(HH) is equivocal. This study was aimed to compare HRM variables in patients with HH before and after fundoplication and to evaluate diagnostic performance of HRM in detecting sliding HH.

Methods Sensitivity and specificity of HRM were assessed in 31 patients(20 females; mean age 48.2) with gastroesophageal reflux disease who were qualified for Nissen fundoplication and underwent preoperative HRM. Intraoperative diagnosis of HH was the gold standard. Area under curve(AUC) of receiver operating characteristic(ROC) reflecting diagnostic accuracy of HRM was also computed. Eleven patients(5 females; mean age 52.1) out of 31 were selected who underwent both: HRM before fundoplication(preoperative group) and at least 3 months after surgery(postoperative group). Manometric protocol included 10 consecutive swallows of 10 ml of water. Variables from pre and postoperative group were compared using paired Wilcoxon test.

Results 29 patients out of 31 were found to have HH during surgery while 14 patients had manometric criteria for HH(mean HH size was 2.44 cm). Sensitivity and specificity of HRM in detecting HH were 48% and 100% respectively. AUC under ROC curve for HRM was 0.74 indicating limited usefulness of this method; regarding threshold value of 0.8 for clinical practise. HRM profile of HH in preoperative group is characterised by significantly lower minimal basal esophagogastric junction(EGJ) pressure as well as integrated relaxation pressure(IRP) comparing to postoperative group without HH. IRP values were within normal range in both examined groups( < 15 mmHg). Although mean basal EGJ pressure was lower in preoperative than in postoperative group, the difference between groups didn’t reach statistical significance. Neither DCI nor IBP was affected by fundoplication. Data is shown in table.

Conclusion HRM is not reliable tool to diagnose HH. Due to poor sensitivity of HRM in detecting HH, manometric profile of patients with HH versus those without should be evaluated with caution. Surgical correction of HH contributes to higher EGJ relaxation pressure and improvement of antireflux barrier however neither bolus pressurisation nor DCI is affected by fundoplication.

Disclosure of Interest None Declared