New techniques to evaluate esophageal function

Classical techniques like videofluoroscopy, stationary manometry and ambulatory 24-hour pH-metry are routinely used in the clinic to study patients with dysphagia, chest pain and reflux-related symptoms. Although many patients can be accurately diagnosed and their therapy successfully guided with these techniques, in many other patients, non-obstructive dysphagia or chest pain cannot be attributed to clear fluoroscopic or manometric abnormalities. Furthermore, ambulatory 24-hour pH-metry often shows a poor association between spontaneous acid reflux events and esophageal or extraesophageal symptoms, particularly in patients 'on' treatment. Non-obstructive dysphagia can be assessed with high-resolution manometry to detect segmental disturbances of peristalsis, increase in pressure gradient across the lower esophageal sphincter (LES) or abnormal axial movement of the LES during esophageal spasm. Impedance evaluation of bolus transit is a non-radiological method that can evaluate the functional relevance of manometric abnormalities. Patients with non-cardiac chest pain that do not respond to proton pump inhibitor therapy can be further assessed with intraluminal high-frequency ultrasound to detect sustained esophageal contractions of the longitudinal muscle layer. Impedance planimetry, with multimodal esophageal stimulation, may contribute to evaluate the sensitivity to mechanical, thermal and chemical stimuli. Finally, patients with persistent symptoms of gastroesophageal reflux in spite of adequate treatment with proton pump inhibitors may still have weakly acidic reflux and/or bile reflux associated with their symptoms. These types of refluxates can now be detected with combinations of pH-impedance or pH-Bilitec monitoring. This review will describe the available new techniques to evaluate patients with non-obstructive dysphagia, non-cardiac chest pain and persistent gastroesophageal reflux symptoms.