The primary esophageal motility disorders are characterized by abnormalities that interfere with swallowing and the transit of food through the esophagus, producing symptoms of dysphagia and chest pain. The disorder is considered primary when the cause of the patient's symptoms and altered motility cannot be attributed to other systemic diseases (e.g., diabetes mellitus, scleroderma, amyloidosis, or neuromuscular disorders that affect striated muscle). One classic disorder is achalasia, which is characterized by failure of the lower esophageal sphincter to relax. There are several other nonspecific esophageal motility disorders, including diffuse esophageal spasm (DES), nutcracker esophagus, hypercontracting esophagus, and other abnormalities of the lower esophageal sphincter. Whether these represent true disorders, a continuum of disease, or merely abnormal motility patterns that are associated with but are not the physiologic causes of symptoms remains a controversy (Table 24-1).
Table 24-1. Classification of Primary Esophageal Motility Abnormalities |Favorite Table|Download (.pdf)
Table 24-1. Classification of Primary Esophageal Motility Abnormalities
Decreased and simultaneous contractions in distal esophagus
Incomplete LES relaxation (residual pressure >8 mm Hg)
Elevated resting LES pressure (>45 mm Hg)
Increased baseline esophageal pressure
Abnormal motility patterns (nonspecific esophageal dysmotility)
Diffuse esophageal spasm
Simultaneous contractions (>20% wet swallows)
Repetitive contractions (>3 peaks)
Prolonged duration contractions (6 s)
Increased distal peristaltic amplitude (mean value >180 mm Hg)
Hypertensive peristalsis (nutcracker esophagus)
Increased distal peristaltic duration (mean value >6 s)
Resting LES pressure >45 mm Hg
Associated with incomplete relaxation (residual pressure >8 mm Hg)
Increased nontransmitted peristalsis (mean value ≥ 30%)
Low distal peristaltic amplitude (<30 mm Hg)
Resting LES pressure < 10 mm Hg
Triple peaked contractions
Isolated incomplete LES relaxation (8 mm Hg)
Lack of a meaningful classification system adds to this confusion. Current systems classify the disorder based on aberrant esophageal motility patterns documented on manometric studies in the context of dysphagia and pain that cannot be explained by other thoracic or cardiac disease. These systems fall short because the causes of most motility abnormalities are unknown. Patients can have abnormal manometric tracings and be perfectly healthy. Conversely, therapies may correct the abnormal tracing, but symptoms do not improve. Strategies for managing esophageal dysmotility disorders include conservative management, treatment with drugs and other agents, and surgery. In the sections that follow, we review current knowledge about the pathophysiology of the primary esophageal motility disorders and recent advances in diagnosis and treatment.
The normal human esophagus has two sphincters that control the passage of food and prevent gastric acid reflux from the stomach. These are the upper esophageal sphincter (UES) and the lower esophageal sphincter (LES). The LES is adversely affected in many of the primary esophageal motility disorders. The normal LES is located in the distal esophagus just above the gastroesophageal (GE) junction. It has a ...