| 释义 |
lower esophageal ring
lower esophageal ring[‚lō·ər i‚saf·ə‚jē·əl ′riŋ] (medicine) Schatzki's ring Lower Esophageal Ring
Lower Esophageal Ring DefinitionLower esophageal ring is a condition in which there is a ring of tissue inside the lower part of the esophagus (the tube connecting the throat with the stomach). This tissue causes narrowing and partial blockage of the esophagus. Lower esophageal ring can also refer to the ring itself.DescriptionLower esophageal ring (also called Schatzki's ring and B-ring) affects about 10-14% of the population. Normally, the lower part of the esophagus, near where the esophagus meets the stomach, has an inside diameter of 1.5-2 inches. The diameter of this part of the esophagus is less when lower esophageal ring is present, and diameters as small as one-eighth inch have been seen. When the inside diameter is less than about three-fourths of an inch, intermittent difficulty with swallowing can result. About 96% of people with lower esophageal ring have no symptoms.Causes and symptomsCausesLower esophageal ring seems to result from infoldings of tissue near the bottom of the esophagus, but the underlying cause is unknown. Although some specialists speculate they are due to a congenital defect, most people do not develop symptoms until they reach their forties or later. Although lower esophageal ring is generally associated with hiatal hernia, and sometimes with heartburn, the cause/effect relationship is unclear.SymptomsIntermittent difficulty swallowing solid food is the primary symptom of this condition. The degree of difficulty in swallowing is directly related to the degree the esophagus is narrowed. Certain foods, especially tough or fibrous foods like meat, are more likely to cause swallowing difficulties.DiagnosisGastroenterologists and internists are best equipped to diagnose and treat lower esophageal ring. The diagnosis is based on the patient's history of swallowing difficulties and a barium x ray of the upper gastrointestinal tract. For a barium x ray, the patient swallows a liquid containing barium, a sub-stance that is opaque to x rays. Subsequent x-ray photography reveals the shape of the esophagus and any narrow regions present.The presence of a lower esophageal ring can also be shown with a test called an esophagoscopy. This procedure visualizes the inside of the esophagus with an inserted, thin, flexible tube. However, this test is less sensitive for lower esophageal ring and costs about five times as much as barium x ray. However, if the findings of a barium x ray are not definitive, esophagoscopy should be done. Biopsies can then be done on questionable areas.TreatmentDietary changeSwallowing difficulties due to lower esophageal ring can often be relieved by chewing food more thoroughly. Soft foods and liquids may also be recommended.DilationLower esophageal rings can be corrected by passing a bougie (a cylindrical, mercury-filled dilator) through the esophagus. This procedure, called bougienage, is effective most of the time, but may need to be repeated every few years. Complications and adverse reactions are extremely rare.SurgeryIf bougienage is unsuccessful, lower esophageal ring tissue can be surgically removed.PrognosisThe probability of a favorable outcome is high. Swallowing difficulties can be alleviated in almost every case, and the rate of complications from bougienage or surgery is less than 1%.PreventionSince the cause of lower esophageal ring is not known, there are no definitive preventive measures. Nevertheless, anyone with lower esophageal ring who also suffers from heartburn would be wise to prevent or treat the heartburn. It is possible that the stomach acid in the esophagus associated with heartburn contributes to esophageal ring.ResourcesOrganizationsThe American College of Gastroenterology (ACG). P.O. Box 3099, Alexandria, VA 22302. (800) 432-2876. http://www.healthtouch.com.American Gastroenterological Association (AGA). 7910 Woodmont Ave., 7th Floor, Bethesda, MD 20814. (310) 654-2055. 〈aga001@aol.com〉 http://www.gastro.org/index.html.American Society for Gastrointestinal Endoscopy. 13 Elm St., Manchester, MA 01944. (508) 526-8330. 〈http://www.asge.org/doc/201〉.National Digestive Diseases Information Clearinghouse. 2 Information Way, Bethesda, MD 20892-3570. (800) 891-5389. http://www.niddk.nih.gov/health/digest/nddic.htm.Key termsBougie — A mercury-filled dilator in the shape of a cylinder or tapered cylinder. Bougies come in a range of different sizes.Bougienage — The procedure of dilating tubal organs, like the esophagus, with a bougie or bougies.Congenital — Existing at birth.Dysphagia — Difficulty swallowing.Esophagoscopy (also esophagoendoscopy) — Examination of the inside of the esophagus using a flexible tube that transmits video images.Esophagus — The tube connecting the throat to the stomach, which is about ten inches long in adults. It is coated with mucus and surrounded by muscles, and pushes food to the stomach by sequential waves of contraction. It functions to transport food from the throat to the stomach and to keep the contents of the stomach in the stomach.Heartburn — A burning sensation in the chest that can extend to the neck, throat, and face, caused by the movement of stomach acid into the esophagus.Hiatal hernia — A condition where part of the stomach extends through the diaphragm into the chest cavity. |