Manometric Studies

The gastrointestinal tract is a long, muscular tube in which the coordinated relaxation and contraction of smooth muscle, expressed as peristalsis, actions of various sphincters, and accommodation to the bulk of ingested food and secretions play an important role in normal digestive function. Increasingly, abnormalities in gastrointestinal neuromuscular activity are recognized as being responsible for clinical disorders.

I. ESOPHAGEAL MOTILITY STUDIES.

The main purpose of the esophagus is to transport food and secretions to the stomach. It performs this task through a series of coordinated events that begins when a solid or liquid bolus is propelled to the back of the mouth and into the pharynx by the tongue. Thereafter, the process of swallowing becomes “automatic.” First, the upper esophageal sphincter (UES), which constricts the esophagus just below the pharynx, relaxes as the pharynx contracts and the bolus passes into the upper esophagus. Next, a primary peristaltic contraction propels the bolus down the esophagus but usually is insufficient to carry the bolus the entire length of the esophagus.

Secondary peristaltic contractions are initiated when the esophagus is distended by the bolus, and these contractions finish moving the bolus to the stomach. Finally, as the bolus reaches the mid-to-lower esophagus, the lower esophageal sphincter (LES) relaxes to allow the bolus to pass into the stomach. The tonic contraction of the LES, which relaxes during swallowing, normally presents an effective barrier against reflux of gastric contents into the esophagus.

A. Indications and contraindications.

Esophageal manometry is useful in diagnosing disorders of motility or a dysfunctional UES or LES (Table 8-1). Typically, patients with motility disorders complain of dysphagia, usually to both liquids and solids (see Chapter 20). Esophageal manometry also is useful in the evaluation of patients with noncardiac chest pain (see Chapter 21). Some of these patients can be shown to have esophageal spasm or a related motility disorder. Finally, esophageal manometry sometimes is used in the evaluation of patients with severe gastroesophageal reflux to document impairment of peristalsis or LES function (see Chapter 19). Patients with reflux symptoms usually do not require esophageal manometry, however.

Esophageal manometry should not be performed in a patient who is unwilling to cooperate in swallowing the tube or in a patient with severe mechanical esophageal obstruction.

B. Method of performing esophageal manometry.

Patients are asked to fast for 6 to 8 hours before the study. Usually no sedatives or topical anesthetics are given because these medications may interfere with esophageal motor function. If the patient is unable to swallow the tube, however, a small amount of topical anesthetic may be applied to the pharynx or, if the tube is to be passed through the nose, to the internal nares. Patients may return to their usual activities and diet after completion of the study.

The typical manometry tube has three recording probes (either perfused catheter tips or solid-state transducers) arranged linearly toward the distal end of the tube (Fig. 8-1

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