Esophageal manometry is a diagnostic test used to assess the function of the esophagus, the muscular tube connecting the mouth to the stomach. It is often recommended when individuals experience symptoms such as difficulty swallowing, chest pain not related to heart issues, or regurgitation. This test helps pinpoint issues with the muscle movements and valves that are crucial for proper food transport.
What Esophageal Manometry Measures
The esophagus contains two sphincters: the upper esophageal sphincter (UES) at the top, and the lower esophageal sphincter (LES) at the junction with the stomach. The UES relaxes to allow food entry and contracts to prevent air intake. The LES relaxes to permit food passage into the stomach and contracts to prevent reflux.
Between these sphincters, the esophageal body propels food downward through peristalsis, a wave-like series of muscle contractions. This wave-like motion is essential for efficiently moving swallowed food and liquids into the stomach. Esophageal manometry uses a thin, flexible tube with pressure sensors to record the strength, speed, and coordination of these contractions and sphincter relaxation.
Decoding the Manometry Report
Manometry reports, particularly from high-resolution manometry (HRM), present data as color-coded pressure tracings or topographic maps. These visuals represent pressure changes along the esophagus, allowing identification of muscle activity patterns. Key measurements extracted from these tracings quantify esophageal function.
The Integrated Relaxation Pressure (IRP) assesses how well the lower esophageal sphincter relaxes during swallowing. A high IRP indicates inadequate LES relaxation, impeding food passage. The Distal Contractile Integral (DCI) quantifies the strength of peristaltic contractions in the esophageal body. Normal DCI values range from 450 to 8000 mmHg·s·cm; values outside this range indicate weak or excessively strong contractions.
The Contraction Front Velocity (CFV) measures the speed of the peristaltic wave. The Distal Latency (DL) indicates the time from UES relaxation to the esophageal contraction reaching strength in the lower esophagus. A short distal latency (less than 4.5 seconds) can suggest premature or spastic contractions. The report also details the resting pressures of both the UES and LES, providing insight into their baseline function. These numerical values, along with the visual patterns, help characterize the esophageal motor function.
Common Esophageal Conditions Revealed by Manometry
Esophageal manometry diagnoses specific motility disorders by identifying characteristic patterns of abnormal measurements. Achalasia is identified by a high Integrated Relaxation Pressure (IRP), indicating poor lower esophageal sphincter relaxation, coupled with absent or severely impaired peristalsis. Types of achalasia include Type I (no peristalsis), Type II (pan-esophageal pressurization), and Type III (premature or spastic contractions).
Esophagogastric Junction (EGJ) Outflow Obstruction shows an elevated IRP, similar to achalasia, but with preserved peristalsis. This suggests an LES blockage while the esophageal body still attempts to push food. Major motility disorders include Distal Esophageal Spasm, marked by premature contractions (short distal latency) and often high DCI, and Hypercontractile Esophagus (“jackhammer esophagus”), defined by excessively strong contractions with very high DCI values (above 8000 mmHg·s·cm). Absent Contractility is diagnosed when peristaltic contractions are entirely missing, often with a very low DCI.
Minor motility disorders, such as Ineffective Esophageal Motility (IEM), are characterized by frequent weak or failed swallows. This means a significant number of swallows have a low DCI (below 450 mmHg·s·cm), indicating insufficient contractile vigor. These distinct manometric signatures guide clinicians in identifying the underlying cause of a patient’s symptoms and inform treatment strategies.
Beyond the Report: Diagnosis and Next Steps
The esophageal manometry report provides valuable data, but it is one component of a broader diagnostic process. A gastroenterologist or motility specialist interprets these results alongside a patient’s symptoms and medical history. Manometry findings are often combined with information from other diagnostic tests.
For instance, an upper endoscopy might rule out structural issues or inflammation, while a barium swallow visualizes anatomy and food movement. Combining this information allows healthcare professionals to reach a definitive diagnosis and develop the most appropriate, tailored treatment plan.