The esophagus is a muscular tube that carries food from the mouth to the stomach. The stomach makes acid, which participates in the digestion of food. There is a valve between the esophagus and stomach that normally prevents acid and other stomach contents from being refluxed back into the esophagus. However, many people in the United States have a weak valve, and acid can reflux back onto the lining of the esophagus eventually resulting in Barrett's esophagus.
Normally, the esophagus is lined by a white tissue that is similar to the skin on the forearm, whereas the stomach is lined by a red, mucus-secreting tissue that is resistant to acid. When acid is refluxed onto the white lining of the esophagus, it can cause pain, which can be felt as heartburn or indigestion. If the acid reflux is not treated effectively, it can cause damage to the white lining of the esophagus.
After enough damage, the normal white esophageal lining can become replaced with a red lining that is called "Barrett's esophagus". This red lining secretes mucus and is therefore more resistant to acid than the normal white lining. However, the red lining of Barrett's esophagus is abnormal and differs from the normal red lining of the stomach. In a minority of patients (approximately 5-10%), a subpopulation of cells within the red lining (Barrett's esophagus) can progress to become a cancer.
The premalignant lining of Barrett's esophagus can be seen at endoscopy and diagnosed by endoscopic biopsy. Therefore, it is recommended that patients who have chronic heartburn or indigestion undergo endoscopy with biopsy to determine whether or not they have developed Barrett's esophagus.
Barrett's esophagus had no cure, short of surgical removal of the esophagus, which is a serious operation, until the use of the HALO360 Ablation System (see in treatment section). Most physicians have recommended treating GERD with acid-blocking drugs, since this is sometimes associated with improvement in the extent of the Barrett's tissue. However, this approach has not been proven to reduce the risk of cancer. Treating reflux with a surgical procedure for GERD also does not seem to cure Barrett's esophagus.