Achalasia is a motility disorder of the oesophagus, of unknown cause, which results in degeneration of the myenteric nerve plexus of the oesophageal wall resulting in deranged oesophageal peristalsis and loss of lower oesophageal sphincter function.
The diagnosis of achalasia is typically suspected in a patient with dysphagia to both solids and liquids with associated regurgitation of undigested food. The following are the diagnostic modalities often employed in achalasia.
Most patients presenting with dysphagia require esophagogastroduodenoscopy (EGD) primarily to rule out a mechanical obstruction due to cancer that can mimic achalasia both clinically and manometrically.
Esophageal dilation with a gradual taper down to the gastroesophageal junction giving a “bird’s beak” appearance is the classic description of achalasia on barium esophagram. Timed barium esophagogram (TBE) is an objective way to determine esophageal emptying
It is the gold standard for the diagnosis of achalasia. It functions to assess esophageal pressures along the length of a flexible catheter inserted into the esophagus. High resolution manometry can display pressure data as esophageal topography plots.
Endoluminal Functional Lumen Imaging Probe (EndoFLIP)
EndoFLIP works on the principle of impedence planimetry and allows the measurement of gastroesophageal junction(GEJ) distensibility in real time. This may be a better parameter than LES pressure to evaluate the efficacy of treatment.
It can be managed but not cured. There are 5 major treatment modalities
Oral pharmacologic therapies are considered the least effective treatment option for achalasia. The clinical response to these agents is short lived and their side effect profile is unfavorable. The two most commonly employed medications are calcium channel blockers and long-acting nitrates.
Botulinum toxin is a useful treatment strategy for patients who are unable to tolerate more invasive therapies, such as pneumatic dilatation or surgical myotomy. The technique involves injecting up to 100 units of toxin with a sclero-needle just proximal to the squamo–columnar junction evenly distributed over four quadrants. The response rate in the first month of treatment is high at 80%–90%; however, the therapeutic effect wanes rapidly over time such that ∼50% of patients are symptomatic at 1 year. Thus, repeat treatments every 6–12 months are often required.
Pneumatic Dilation (PD)
Surgical myotomy, a technique involving the division of the circular muscle fibers of the LES, was initially performed via an open thoracotomy and laparotomy approach.
But,with time, old open approach was replaced with more minimally invasive techniques; first with thoracoscopy which was subsequently replaced with Laparoscopic Heller Myotomy (LHM) because of improved morbidity and faster recovery time. Now, LHM is accepted as the standard of surgical management for AC.
“End-stage” achalasia, characterized by a dilated and tortuous esophagus (megaesophagus or sigmoid esophagus), is often unresponsive to conventional treatments for achalasia. Although PD is ineffective, surgical myotomy should still be considered the initial treatment before consideration of the more morbid esophagectomy.
Advances in treatment for achalasia
Peroral endoscopic myotomy: Peroral endoscopic myotomy (POEM) is a novel endoscopic procedure that uses the oral cavity as a natural orifice entry point to perform myotomy of the LES. After tunneling an endoscope down the esophagus toward the esophageal gastric junction, a surgeon performs the myotomy by cutting only the inner, circular LES muscles through a submucosal tunnel created in the proximal esophageal mucosa.
POEM differs from laparoscopic surgery, which involves complete division of both circular and longitudinal LES muscle layers. The dysfunctional muscle fibers that prevent the LES from opening are cut in order to allow food to enter the stomach more easily.