A cause of dysphagia
 |
| 1. What is this radiological investigation? |
| 2. What diagnostic features does it show? |
 |
|
This is a barium swallow showing the typical 'rat tail' appearance of achalasia of the cardia. Achalasia of the cardia is a functional failure of relaxation of the lower oesophageal sphincter. Histological examination shows degeneration of the ganglion cells in the myenteric plexus and changes within the Vagus nerves. Lymphocytic infiltration is often seen with fibrosis occurring in chromic cases. The aetiology is unknown although infection with a neurotropic virus affecting the autonomic nervous system has been suggested. Chagas' disease due to infection with Trypanosoma cruzi, seen in South America, results in damage to the myenteric plexus and causing similar oesophageal appearances. Achalasia is a disease of middle age with equal preponderance in either sex. The commonest clinical presentation is with insidious onset of dysphagia with patients often having symptoms for several years before seeking medical advice. This is in contrast to the symptoms of oesophageal cancer where the symptoms progress over weeks and months. Dysphagia occurs with both solids and fluids often helping in differentiating it from mechanical obstruction where symptoms occur with solids before fluids. Other presenting symptoms include weight loss, regurgitation and chest complaints, particularly nocturnal cough and wheeze. Approximately 10% of patients develop the more serious respiratory complications of aspiration pneumonia, lung abscess and bronchiectasis. About 5% of patients with long standing disease develop squamous carcinoma of the oesophagus. This is thought to result from prolonged exposure to carcinogens in food. A chest x-ray is usually normal in the early stages of the disease. In the later stages, widening of the mediastinum, a mediastinal air-fluid level or absence of the gastric fundal gas shadow is often seen. In the early stages of the disease, a barium swallow may show a reduction in the peristaltic waves. With time, the oesophagus becomes dilated with food residue often identified. The 'rat tail' tapering of the oesophagus is typical. Endoscopy is essential to exclude a submucosal carcinoma of the cardia producing the radiological picture of 'pseudoachalasia'. In long standing cases oesophagitis and oesophageal candidiasis may be seen at endoscopy. The gastro-oesophageal sphincter is typically tightly closed but relaxes suddenly if gentle pressure is applied with the endoscope. Manometric studies, if performed, show absence of the primary peristaltic wave with simultaneous non-propulsive 'tertiary contractions' The differential diagnosis is:
Definitive treatment aims to disrupt the circular muscle of the lower oesophageal sphincter by either surgery or pneumatic balloon dilatation. Oesophageal peristalsis cannot be restored and swallowing therefore never returns completely to normal. Oesophageal balloon dilatation has replaced the use of older mechanical and hydrostatic devices. It is performed in an endoscopy suite under intravenous sedation. Oesophageal lavage may be required before the procedure if there is a large amount of food residue in the oesophagus. A guide wire is advanced into the stomach and the balloon positioned under fluroscopic control. The above picture shows the radiological markers used to position the balloon which is then inflated to about 300 mmHg for three minutes and then removed. The most significant complication is perforation that can occur in up to 5% of procedures. Most perforations can be managed conservatively. Good results from balloon dilatation are obtained in most patients with 60% of patients dysphagia free at 5 years. Dysphagia recurs in about 20% who require further and often repeated dilatations. Cardiomyotomy entails surgical division of the lower oesophageal sphincter and was first described by Heller in 1914. Goenveldt in 1918 modified the early double myotomy on both the anterior and posterior aspects of the oesophagus to a single anterior incision. It can be performed by either an abdominal or thoracic approach with the muscle being split down to the mucosa. Mortality rates of less than 1% and success rates of over 85% have been recorded. There is however a high incidence (up to 10%) of oesophageal reflux post-operatively progressing in a number of cases to peptic stricture. The use of an antireflux procedure at the time of the myotomy is occasionally recommended by some surgeons. Endoscopic cardiomyotomy has recently been described. Recent paperBanerjee S, Clements D, Smith P M. Achalasia of the cardia. Hospital Update 1993; 9: 480-488. Hunter J G, Richardson W S. Surgical management of achalasia. Surg Clin N Am 1997: 77: 993-1115.
|
Last modified: