The minimally invasive surgical approach to achalasia: a new standard of care?

Achalasia is a rare primary motor disorder of the esophagus, characterized by the triad of esophageal aperistalsis, failure of the lower esophageal sphincter (LES) to completely relax with swallowing, and a hypertensive or sometimes normal pressure LES. The pathophysiology of achalasia results in progressive dysphagia and intermittent regurgitation as well as esophageal dilatation. The exact etiology of achalasia is uncertain, although the pathology has been distinguished in recent literature by the absence of post-inhibitory neurons in Auerbach’s myenteric plexus. Although the incidence of esophageal achalasia is low, occurring in 0.5 to 1 of 100,000 individuals in Western countries, achalasia represents the most frequent esophageal motility disorder. Ernest Heller, a pioneer in the surgical treatment of achalasia, is credited with the first performance of concomitant posterior and anterior cardiomyotomies in 1914. This surgical approach was modified by Groeneveldt in 1918, and by Zaaijer in 1923 to a single anterior cardiomyotomy. The largest experience with cardiomyotomy is in Brazil due to the prevalence of Chagas’s disease, which may progress to a motility disorder similar to achalasia. The treatment for achalasia lends itself well to a minimally invasive approach. The laparoscopic approach enables precise division of the esophageal and cardiac muscle fibers by offering a magnified view of the esophagus and gastroesophageal junction. Laparoscopic cardiomyotomy studies by Hunter and Ancona demonstrate outcomes comparable to conventional open cardiomyotomy. Thoracoscopic esophageal myotomy also provides good results in the treatment of achalasia. It is important to note that none of the current surgical or endoscopic treatments addresses the etiology of the disease itself; these procedures are merely palliative in nature. A full discussion of the diagnostic studies for achalasia, medical and endoscopic treatment, and open cardiomyotomy is presented in the companion article. Briefly, manometry can identify the poorly contractile esophagus and incompletely relaxing LES of achalasia. Achalasia patients also have tertiary, low-amplitude, simultaneous contractions. Vigorous achalasia is characterized by forceful contractions, as in diffuse esophageal spasm, combined with a contracted LES. A barium swallow study may complement the manometric findings by revealing a dilated, often tortuous, “sigmoid-shaped” esophagus tapering to a narrow “bird’s beak” proximal to the gastroesophageal junction. Esophageal endoscopy typically demonstrates a dilated esophagus that tapers distally and often reveals the presence of retained food or esophagitis. Yeast esophagitis should be aggressively treated preoperatively to avoid the catastrophic sequellae of fungal mediastinitis should a mucosal injury occur during esophageal myotomy. Importantly, the LES in achalasia yields to the endoscope to allow it to “pop” into the stomach. This endoscopic characteristic distinguishes achalasia from an esophageal stricture or “pseudoachalasia.” Pseudoachalasia, a condition in which a tumor exerts a mass effect on the distal esophagus, mimics the fluoroscopic and clinical findings of achalasia. If pseudoachalasia is suspected, a computed tomography scan should be performed to check for malignancy.