Achalasia is absent or ineffective peristalsis of the distal esopha-gus, accompanied by failure of the esophageal sphincter to relax in response to swallowing. Narrowing of the esophagus just above the stomach results in a gradually increasing dilation of the esoph-agus in the upper chest. Achalasia may progress slowly and occurs most often in people 40 years of age or older.
The primary symptom of achalasia is difficulty in swallowing both liquids and solids. The patient has a sensation of food sticking in the lower portion of the esophagus. As the condition progresses, food is commonly regurgitated, either spontaneously or intention-ally by the patient to relieve the discomfort produced by prolonged distention of the esophagus by food that will not pass into the stomach. The patient may also complain of chest pain and heart-burn (pyrosis). Pain may or may not be associated with eating. There may be secondary pulmonary complications from aspiration of gastric contents.
X-ray studies show esophageal dilation above the narrowing at the gastroesophageal junction. Barium swallow, computed tomography (CT) of the esophagus, and endoscopy may be used for diagnosis; however, the diagnosis is confirmed by manometry, a process in which the esophageal pressure is measured by a radiologist or gas-troenterologist.
The patient should be instructed to eat slowly and to drink flu-ids with meals. As a temporary measure, calcium channel block-ers and nitrates have been used to decrease esophageal pressure and improve swallowing. Injection of botulinum toxin (Botox) to quadrants of the esophagus via endoscopy has been helpful because it inhibits the contraction of smooth muscle. Periodic injections are required to maintain remission. If these methods are unsuccessful, pneumatic (forceful) dilation or surgical sep-aration of the muscle fibers may be recommended (Streeter, 1999; Annese et al., 2000).
Achalasia may be treated conservatively by pneumatic dilation to stretch the narrowed area of the esophagus (Fig. 35-6). Pneu-matic dilation has a high success rate. Although perforation is a potential complication, its incidence is low. The procedure can be painful; therefore, moderate sedation in the form of an anal-gesic or tranquilizer, or both, is administered for the treatment. The patient is monitored for perforation. Complaints of abdom-inal tenderness and fever may be indications of perforation (see later discussion).
Achalasia may be treated surgically by esophagomyotomy (Fig. 35-7). The procedure usually is performed laparoscopically, either with a complete lower esophageal sphincter myotomy and an antireflux procedure (see later discussion of fundoplasty), or without an antireflux procedure. The esophageal muscle fibers are separated to relieve the lower esophageal stricture. Although pa-tients with a history of achalasia have a slightly higher incidence of esophageal cancer, long-term follow-up with esophagoscopy for early detection has not proved beneficial.