الفهرس 
Embryology of the OesophagusOnly 14 pages are availabe for public view
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Abstract
The cause of achalasia is unknown. There is loss of nerve cells in the Auerbach’s plexus between the two muscle layers of the esophageal wall and in the lower esophageal sphincter. This defect results in loss of peristalsis, and failure of the lower esophageal sphincter to relax. These changes result in failure of esophageal emptying and retention of solid and liquid foods in the esophagus.
Dysphagia, regurgitation, heart burn and chest pain are the most annoying symptoms in patients with achalasia. Regurgitation, especially at night when the patient is recumbent, can result in aspiration of fluid into the lungs causing bronchitis and pneumonia.
Once the diagnosis is established, a decision regarding therapy is in order. Some patients with early achalasia and mild symptoms may elect to delay treatment or try medical (drug) treatment. Such treatment with calcium channel blocker drugs may help by transiently relaxing the closed sphincter but this response is usually short-lived and not reliable for long-term use.
The standard medical treatment option is dilation of the tight sphincter with balloon dilators. These instruments are intended to over-stretch the sphincter to the point that the muscle fibers lose their ability to contract tightly and thereby allow the esophagus to empty more efficiently. This form of therapy provides good to excellent improvement in 70 to 90% of patients. The main risk of this treatment is perforation or full-thickness tear of the esophagus that occurs in 2 to 5% of patients. If this occurs a surgical operation usually is needed to close the tear.
Another treatment for achalasia used for the past 10 years is the injection of Botulinum toxin (Botox) into the esophageal sphincter. It prevents the release of a chemical (acetylcholine) from the nerves in the lower esophageal sphincter resulting in relaxation and reduction of the high sphincter pressure. Improvement of the patient’s swallowing and regurgitation in about 80% of cases. Its only significant drawback is a limited duration of relief.
In the past years, when balloon dilations had failed on two occasions, an operation called a Heller myotomy was recommended. This surgical procedure gave good to excellent results and can be done either through transthoracic or transabdominal approach. Currently laparoscopic myotomy can be performed, As more experience has been gained this procedure has become the preferred technique. Current long-term improvement is being confirmed in over 80% of cases. If the sphincter muscle is rendered too weak by myotomy, there is a risk for acid in the stomach to reflux into the esophagus and cause esophagitis or a stricture. Surgeons may attempt to reduce this risk by performing an antireflux operation at the time of the myotomy. Even if this problem occurs the acid reflux can be adequately treated by acid suppressing drugs.
It can be concluded that laparoscopic myotomy is considered the best option for treating patients with achalasia among all therapeutic method because it shows the best long-term results, particularly in young patient, and this laparoscopic procedure is considered to be minimally invasive. Pneumatic dilatation should be seen as the second-line therapeutic option. This method also shows good long-term results, but has a higher complication rate. Botulinum toxin injection should only be considered for selected patients as in elderly patients, patients with severe comorbidity.