vMII for Measurement of Oesophageal Bolus Transport and Reflux

Recent work at St. Thomas' has validated an innovative new design of a multichannel intraluminal impedance (MII) catheter that is sensitive to variation in oesophageal volume in healthy volunteers and patients. This project will establish the clinical value of volume sensitive MII (vMII) compared to conventional MII acquired simultaneously by the same catheter (ROC analysis). Studies will assess: 1. The accuracy of volume measurements and correlation between symptoms and the volume of bolus retention in patients with dysphagia. 2. The accuracy of volume measurements and correlation between symptoms and reflux volume in patients with reflux disease. Follow up studies after appropriate treatment will assess whether symptomatic improvement is associated with a reduction in oesophageal volume retention/reflux. The vMII technique will be applied with high resolution manometry (HRM). These investigations are complementary in that vMII assesses the success or failure of bolus transport (or occurrence of reflux) and HRM can assess: 1. the oesophageal dysfunction that results in bolus escape 2. the abnormal events at the gastro-oesophageal junction (reflux barrier) that allow reflux to occur. with a reduction in oesophageal volume retention / reflux.