High-resolution Manometry in Patients with Gastroesophageal Reflux Disease Before and After Fundoplication

BACKGROUND/AIMS: The study aimed to determine pre- and post-fundoplication esophagogastric junction (EGJ) pressure and esophageal peristalsis by high-resolution manometry (HRM) in patients with gastroesophageal reflux disease (GERD). METHODS: Pre-operative and post-operative HRM data from 25 patients with GERD were analyzed using ManoView version 2.0.1. with updated software for Chicago classification and pressure topography. The study involved swallowing water boluses of 10 mL in the upright position. RESULTS: Significant increase of mean basal EGJ pressure and minimal basal EGJ pressure was found in post-operative as compared with preoperative patients (P < 0.05 and P < 0.001, respectively). Integrated relaxation pressure (IRP) reached higher values in post-operative patients than in pre-operative patients (P < 0.001). Intra-bolus pressure (IBP) was significantly higher (P < 0.05) and contractile front velocity (CFV) was slower (P < 0.01) in post-operative patients than in pre-operative patients. Moreover significant increase of distal contractile integral (DCI) was found in post-operative patients (P < 0.05). Hiatal hernia was detected by HRM in 11 pre-operative patients. Fifteen out of 25 post-operative patients complained of dysphagia. CONCLUSIONS: Fundoplication restores the antireflux barrier by reinforcing EGJ basal pressures, repairing hiatal hernias, and enhances peristaltic function of the esophagus by increasing DCI. However slight IRP elevation found in post-fundoplication patients may result in bolus pressurization and motility disorders.

Unreliability of Breath Methane as a Candidate Indicator of Functional Bowel Disorders

BACKGROUND/AIMS: The aim of this study was to examine the reproducibility of methane and hydrogen in exhaled air breath after a per-oral load of lactulose. METHODS: Methane was present in the exhaled breath of 21 of 50 healthy subjects recruited by advertisement. Three methane breath tests were performed in 12 women (aged 23.6+/-0.5 years, mean+/-SEM) after they consumed 10 g of lactulose dissolved in 300 ml of water. Short- and medium-term reproducibilities were assessed by paired examinations taken 3 and 17 days (median) apart, respectively. RESULTS: High values of coefficients of variation for paired examinations (CV(p)) indicated a poor short-term reproducibility of parameters characterizing either the methane or hydrogen excretion in breath air: CV(p) values of the maximum net increments over baseline in methane (max CH4_net), and in hydrogen (max H2_net), were 34% and 41%, respectively. Moreover, the reproducibility consistently deteriorated with increasing time gap between repeat measurements (CV(p): 60% for max CH4_net and 64% for max H2_net). CONCLUSIONS: The low reproducibility of parameters characterizing quantitative methane breath excretion suggests that caution is necessary when judging the clinical usefulness of the methane breath test after a per-oral lactulose load for the purpose of diagnosing and classifying functional bowel disorders.