Pathophysiology of gastroesophageal reflux disease: how an antireflux procedure works (or does not work).

The pathophysiology of gastroesophageal reflux disease is complex and linked to an intricate valve mechanism at the level of the esophagogastric junction that must counteract a trans-diaphragmatic pressure gradient, which is constantly forcing gastric contents upwards. Surgical antireflux therapy is usually aimed towards reinforcement of this valve mechanism. The valve mechanism is made up by the intra-abdominal length of the esophagus; the diaphragmatic sphincter, the angle of His, and the lower esophageal sphincter: all these elements must be restored with an antireflux procedure. Hiatal approximation and fundoplication determine excellent outcomes in patients in whom the abnormal reflux is mostly due to the valve mechanism. In patients with altered intra-abdominal pressure due to obesity, a bariatric procedure such as a Roux-en-Y gastric bypass is probably more appropriate. For patients with an altered intra-thoracic pressure such as in idiopathic pulmonary fibrosis, a fundoplication has been shown to be beneficial in resolving symptoms and avoiding progression of the diseases.