Cardiomyotomy in achalasia: which fibers do we cut?

Until now, it has not been quite clear which muscular fibers are cut when a cardiomyotomy for achalasia is carried out. In the present report, in a human achalasic gastroesophageal specimen, the mucosa of the stenotic segment was stripped off, allowing the fibers of the inner muscular coat to be seen. In addition, three cardiomyotomies at different sites were simulated. In achalasic specimens, the stenotic area is formed by the semicircular ('clasp') and oblique ('sling') muscular fibers. Different myotomies section these two muscular bands in distinct proportions. The stenotic segment in achalasia coincides topographically with the anatomic lower esophageal sphincter area. The site of cardiomyotomy is not irrelevant because this sphincter is not an annular muscle and the two muscular components of the sphincter can be sectioned in different ways. This may be important in post-operative results with regard to the relief of dysphagia and the appearance of gastroesophageal reflux.