Oesophageal manometry
What is oesophageal manometry?
Oesophageal manometry is a procedure for determining how well the muscle of the oesophagus contracts and functions when diseases of the muscle are suspected.
When is oesophageal manometry used?
Oesophageal manometry is used primarily in three situations. The first is to evaluate the cause of reflux (regurgitation) of stomach acid and contents back into the oesophagus (gastro-oesophageal reflux disease or GORD). The second is to determine the cause of problems with swallowing food. The third is when there is chest pain that may be coming from the oesophagus.
How is oesophageal manometry performed?
At the start of the oesophageal manometry procedure, one nostril is anaesthetised with a numbing lubricant. A flexible plastic tube approximately one quarter of a centimeter in diameter is then passed through the anesthetized nostril, down the back of the throat, and into the oesophagus as the patient swallows. Once inside the oesophagus, the tube allows the pressures generated by the oesophageal muscle to be measured when the muscle is at rest and during swallows. It also has sensors to determine how well food is propelled into the stomach. The procedure takes 20 to 30 minutes.
What are the side-effects of oesophageal manometry?
Although oesophageal manometry can be uncomfortable, the procedure is minimally painful because the nostril through which the tube is inserted is anaesthetised. Once the tube is in place, patients talk and breathe normally. The side-effects of oesophageal manometry are minor and can include mild sore throat, nose-bleed, and, uncommonly, sinus problems due to irritation and blockage of the ducts leading from the sinuses and into the nose. Occasionally, during insertion, the tube may enter the larynx (voice box) and cause coughing. When this happens, the problem can be is recognised immediately, and the tube is rapidly removed. Care must be used in passing the tube in patients who are unable to easily swallow on command because without a swallow to relax the upper oesophageal sphincter the tube often doesn't enter the oesophagus but instead enters the larynx.
How is oesophageal manometry used?
The oesophagus is a muscular tube that connects the throat with the stomach. When food is propelled by a swallow from the mouth into the oesophagus, a wave of muscular contraction starts behind the food in the upper oesophagus and travels down the entire length of the oesophagus (referred to as the body of the oesophagus) propelling the food in front of it down the oesophagus and into the stomach. At the upper and lower ends of the oesophagus are two short areas of specialized muscle called the upper and lower oesophageal sphincters. At rest (that is, when there has been no swallow) the muscle of the sphincters is active and generates pressure that prevents anything from passing through them. As a result, material within the oesophagus cannot back up into the throat, and stomach acid and contents cannot back up into the oesophagus. When a swallow occurs, the sphincters relax for a few seconds to allow food to pass.
The most common use for oesophageal manometry is to evaluate the lower oesophageal sphincter in patients who have gastro-oesophageal reflux disease (GORD). Manometry often can identify weakness in the lower oesophageal sphincter that allows stomach acid and contents to back up into the oesophagus.
Manometry can diagnose several oesophageal conditions that result in food sticking after it is swallowed. For example, achalasia is a condition in which the muscle of the lower oesophageal sphincter does not relax with each swallow. As a result, food is trapped within the oesophagus. Abnormal function of the muscle of the body of the oesophagus also may result in food sticking. For instance, there may be failure to develop the wave of muscular contraction (as can occur in patients with scleroderma) or the entire oesophageal muscle may contract at one time (as in an oesophageal spasm). Manometry reveals an absence of the wave in the first case and the contraction of the muscle everywhere in the oesophagus at the same time, or spasm, in the second case.
The abnormal functioning of the oesophageal muscle also may cause episodes of severe chest pain that can mimic heart pain (angina). Such pain may occur if the oesophageal muscle goes into spasm or contracts too strongly. In either case, oesophageal manometry can identify the muscular abnormality.
What limitations are there to the use of oesophageal manometry?
There are several situations in which oesophageal manometry may not demonstrate the oesophageal abnormality that is responsible for a patient's problem. For example, many patients with GORD have transient (coming and going infrequently) but prolonged relaxation (minutes rather than seconds) of the lower sphincter as the cause of their reflux. Such relaxations may be missed in the short period during which the manometric study is being conducted. Similarly, if a patient is having infrequent episodes of chest pain due to oesophageal spasm, for example, every few days or weeks, the spasm may not be seen during a short manometric study. There have been attempts to get around these problems by using portable equipment and prolonged manometry for two or more days; however, prolonged manometry is not commonly performed.
Are there alternatives to oesophageal manometry?
There are no good alternatives to oesophageal manometry. However, special radiological studies using x-rays and swallowed barium (video- fluoroscopic swallowing study) are available. These studies can provide complementary information, for example, by identifying anatomical abnormalities such as narrowing of the oesophagus that also can cause food to stick.
Please download this useful document:
