Difficulties in diagnosis and treatment of mega-oesophagus (a case report).KB Kapadia, RR Satoskar, AE Mody, PP Prabhudesai
Keywords: Aged, Aged, 80 and over, Case Report, Diagnosis, Differential, Esophageal Achalasia, diagnosis,surgery,Esophageal Neoplasms, diagnosis,Esophagitis, complications,Female, Hernia, Hiatal, diagnosis,Human, Scleroderma, Circumscribed, diagnosis,
Mega-oesophagus is a clinical rarity and a medical curiosity. Mega-oesophagus, also known as sigmoid oesophagus, represents the most severe form of achalasia cardia. The average incidence of achalasia cardia is 0.6 per 100,000 persons. In Brazil, there is an unusually large number of cases of mega-oesophagus occurring as a manifestation of Chaga's disease.
An 80 year old female patient weighing 28 kg presented with the complaints of nocturnal cough, wheezing and dyspnoea. She also had dysphagia and nocturnal regurgitation since 20 years. She was wrongly diagnosed before as having pulmonary tuberculosis. A plain chest X-ray showed widening of the mediastinum, an upper mediastinal air-fluid level, a paramediastinal double stripe and pneumonitis. Barium-swallow showed an enormously dilated sigmoid shaped oesophagus with a smooth narrowing at the oesophago-gastric junction. Oesophageal dilatation was attempted using a fibreoptic-scope and hydrostatic dilators. Two attempts of dilatation were made at an interval of 3 weeks, the dilatation balloon being inflated to a pressure of 300 mm Hg for I minute each time. As the dilatation failed, a cardiomyotomy with partial over-wrap of the fundus and gastrostomy were done. The patient had almost a complete relief of dysphagia post-operatively.
Mega-oesophagus occurs long after the development of obstruction to the oesophagus. In the early stages, the symptoms are intermittent with periods of complete relief interposed. Later they become constant, troublesome and unbearable. Most patients assume special eating habits by themselves. They try to force the food down by swallowing large quantities of water or air or executing the Valsalva's manouvre so as to increase the intrathoracic pressure until the lower oesophageal sphincter (LES) permits the food to pass into the stomach.
The patients seek medical advice mainly due to the complications of the disease rather than the cardinal symptoms of dysphagia, regurgitation and pain. Dysphagia is more to liquids and cold food. Regurgitation which is not preceded by nausea and vomiting occurs once in 2-3 days. Regurgitation during sleep is a rule rather than an exception. On awakening the patients find the pillow soiled with oesophageal contents. Pain is absent as there are no contractions in the oesophagus. In a significant number of patients, the respiratory symptoms bring them to the doctor., Chronic pulmonary inflammatory conditions like aspiration pneumonitis, bronchiectasis and pulmonary fibrosis are common in these patients due to aspiration in the recumbent position. Acute aspiration is rare except under anaesthesia, oversedation, alcoholism or unconsciousness. Weight loss is considerable and malnutrition severe. Haemorrhage and halitosis may be present.
Depending on the severity, achalasia could be;-(1) minimal-no dilatation but retention of food in the middle third. Peristalsis is normal in the upper third (striated muscle segment) but disorganised below it (smooth muscle segment); (2) mild-this stage termed as `compensation' has vigorous disorganised motor activity. Radiologically the dilation is less than 4 cm; (3) moderate -decompensation occurs as the oesophagus fails to contract. Uniform dilatation of the entire oesophagus with a tapered lower end resembles a sausage. Radiologically the diameter is 4-6 cm; or (4) severe-Oesophagus becomes tortuous (mega-oesophagus) and dilated giving an appearance of the oesophagus resting on the diaphragm. The oesophagus at this stage is completely paralysed. Its widest diameter is more than 6 cm.
Almost no other condition except megaoesophagus is characterised by a long standing oesophageal obstruction at the hiatus and gross motor abnormality of the entire oesophagus. The diagnosis is established from the history, manometric studies, radiology and oesophagoscopy.
A plain chest X-ray shows mediastinal widening, an air-fluid level at the arch of the aorta and a paramediastinal double stripe. The height of the air-fluid column above the cardia indicates the fluid column the LES can support. Pneumonitis or lung abscess may be seen. On barium swallow, there is absence of peristalsis, gross oesophageal dilation and failure of LES to relax.
Oesophagoscopy is hazardous and difficult due to the risk of perforation of the inflammed wall and aspiration. A rigid scope should be avoided; a Ba-swallow is mandatory before a flexible oesophagoscopy. On careful scopy, the cardia is tightly closed with radial mucosal folds around it giving a `rosette' appearance. A momentary resistance while passing through the cardia and absence of resistance while withdrawal is diagnostic of achalasia.
Mega-oesophagus needs to be differentiated from:
1. Oesophageal carcinoma-A carcinoma has an abnormal mucosal pattern, ulceration and less dilatation.
2. Stricture due to reflux oesophagitis -There is shortening and irregularity of the oesophagus with elevation of the cardia.
3. Scleroderma-The atrophic muscles do not react to inj. methacholipe whereas in achalasia they react with violent contractions:
4. Hiatus hernia-It is ruled out by scopy.
Although various modalities of treatment like bougienage, forceful dilatation (mechanical/hydrostatic/pneumatic) are available, mega-oesophagus should be treated by surgery alone.
Success of the treatment for mega-oesophagus depends on proper pre-operative preparation. (i) Total parenteral nutrition is required for severe malnutrition. (ii) The oesophagus must be completely emptied to prevent aspiration during anaesthesia. (iii) Pneumonitis should be treated. (iv) Oesophagitis must be controlled by doing a temporary gastrostomy.
The dependent pouch of the oesophagus diverts the pressure away from the cardia and hinders emptying. Thus the creation of a dependent oesophago-gastric junction is important. A traps-abdominal approach is preferred. A truncal vagotomy is done first. It reduces peptic oesophagitis, and straightens the oesophagus. (The sigmoid deformity is partly due to the tethering of the oesophagus by the vagus nerve). Thereafter, a cardiomyotomy is performed over a Foley's balloon. To maintain the separation of the myotomy and the oesophago-gastric junction in its place, the cut muscle is sutured to the diaphragmatic crura. The fundus is sutured over the anterior part of the oesophagus to recreate the oesophago-gastric angle. A pyloroplasty is done. A gastrostomy is done to maintain a straight pull on the stomach and thereby maintain the oesophagus below the diaphragm. Naso-gastric tube is avoided as it may injure the delicate oesophageal mucosa.
A fundic patch with fundoplication has been described. Excision of a longitudinal segment of the oesophagus with cardiomyotomy has been reported. A cardiomyotomy with Belsey Mark IV fundoplication using 2 horizontal mattress sutures on each side of the myotomy has also been described.
Potential problems related to the operation are: (1) leakage from mucosal injury, (2) dysphagia due to incomplete myotomy or reapproximation of the cut edges of the muscle if the mucosa is not freed from the muscle for atleast half of the circumference, (3) reflux oesophagitis due to a long myotomy and (4) hiatus hernia-if the hiatal opening has been damaged.
For achalasia the improvement rate after surgery is 92-94% with a 3% incidence of reflux and a 2% mortality.