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INTRODUCTION Clinically, some patients suffered from heartburn, regurgitation, dysphagia, bleeding or chest pain. The motility disorders of esophagus frequently were the cause of the symptoms. In order to solve the problems, a clear understanding of pathophysiologic mechanism of swallowing and determination of the precise functional abnormality of symptoms are essential for the choice of treatment. PHYSIOLOGY OF DEGLUTITION The human esophagus is a muscular tube whose major function is transport of food from the mouth to the stomach. It is founded by a tonically contracted circular muscle sphincter at each end. The upper esophageal sphincter (UES) and the proximal esophagus belong to striated muscle portion, while the distal esophagus belongs to smooth muscle portion. The striated muscle in the proximal esophagus receives direct input to motor end plates and that the cell bodies are located in nucleus ambiguous (NA). In contrast, the smooth muscle portion, like that of the rest of the gastrointestinal tract, has indirect neural input into the muscles through the myenteric plexus. The ganglia originate in the dorsal motor nucleus (DMN) of the vagus nerve.
The traditionally swallowing or deglutition has been divided into three stages in the oral (voluntary) stage, the pharyngeal (involuntary) stage, and the esophageal stage. These three are closely coordinated and continuing processes that are regulated through the swallowing center in the medulla. The normal subjects have the good relaxation of UES and LES and good esophageal peristalsis. But some of the abnormal contractions such as non-peristaltic contraction, simultaneous contraction, nontransmitted contraction, retrograde contraction, will be found in esophageal motility disorder patients. METHODOLOGY FOR ASSESSING MOTOR DYSFUNCTION : The specific methods for assessing motor dysfunction of the esophagus and pharyngoesophageal function are :
The manometry is used most commonly. The provocative esophageal function test, such as acid perfusion test and edrophonium test, has greatest role in differentiating esophageal from cardiac pain. SYMPTOMS OF MOTILITY DISORDERS OF ESOPHAGUSThe main symptoms of esophageal motility disorders are :
According to the type of esophageal muscles involved, we divided the diseases with esophageal motor disorders into two groups :
The esophagogram or UGI series is frequently used in radiology for motor disorders of esophagus. In esophagogram, achalasia had characteristics of 'Bird Beak' configuration and may divide into 3 stages,
Stage I -- minimal -- esophageal diameter of less than 4 cm. Most patients with vigorous achalasia have stage I disease. In diffuse esophageal spasm the esophagogram may have curling or corkscrew shape or appearance of pseudo- diverticulosis. The motor disorder due to gastroesophageal reflux may have esophageal hiatal hernia and esophagitis in UGI series examination. For the Zenker's diverticulum or epiphrenic diverticulum, esophagogram will demonstrate a protruding barium shadow outside the esophageal wall. NON-CARDIAC CHEST PAIN : TREATMENT :For secondary esophageal motility disorders the treatment should be conservatively and medically to relieve the symptom at the beginning. For the primary esophageal motility disorders the possible therapies were as the following table : POSSIBLE THERAPIES FOR PRIMARY ESOPH. MOTILITY DISORDERSI. Medical : 1. Nitrates : Nitroglycerin, isorbide 2. Anticholinergics : Dicyclomine 3. Psychotropic drugs : Diazepam 4. Calcium blocker : Nifedipine 5. Smooth m. relaxant : Hydralazine 6. Static dilatation : 50 French 7. Pneumatic dilatation II. Surgical : Esophagomyotomy If surgery was selected, the operative procedures will be performed for specific location of disease. The procedures and operative results will be summarized in the following table SURGERY FOR ESOPHAGEAL MOTILITY DISORDERS
CONCLUSION : The GER or with hiatal hernia, achalasia, DES, nutcracker esophagus, and hypertensive LES are the common primary motility disorders of the esophagus. All of them have manometric characteristics and can be treated medically and surgically. Different surgeries are recommended after failure of medical treatment. Surgeries will be esophagomyotomy for cricopharyngeal dysfunction, excision or with myotomy for diverticulum, long esophagomyotomy for DES or nutcracker esophagus or hypertensive LES, modified Heller's myotomy for achalasia, anti-reflux operation for GER and scleroderma. Some surgical experiences for treatment of motor disorders of esophagus in Division of Thoracic Surgery of Taipei VGH will be presented and discussed.
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