Medical therapies for achalasia are limited but new procedures are improving management. A gastroenterologist highlights new guidelines.
In December 2019, the American Society for Gastrointestinal Endoscopy (ASGE) released the first set of comprehensive guidelines for the management of achalasia. Published in the February 2020 issue of Gastrointestinal Endoscopy, the ASGE Standards of Practice Guideline provides evidence-based recommendations for treatment of achalasia based on updated evaluations of effectiveness, adverse effects, and cost of the 4 current treatment approaches.
Guidelines on therapy for achalasia have been attempted previously but have not been successfully created due to low quality evidence and lack of randomized trials.
Historically poorly characterized
Achalasia is a well-established cause of difficulty swallowing with an estimated incidence of approximately 3 cases per 100 000 people. It occurs when the myenteric plexus, responsible for relaxing the esophagogastric junction (EGJ), degenerates along with a loss of organized peristalsis in the esophageal body.
For years, the disease was poorly characterized, and thus tailored approaches were not possible. The mainstays of therapy consisted of either a Heller myotomy to cut the lower esophageal sphincter (LES) muscle with fundoplication to reduce the risk of post-surgical reflux or a pneumatic (high pressure) balloon dilation to rupture the muscle. Botulinum toxin injection is also used and helps to relax the LES but does not provide long-lasting results.
Unfortunately, medical therapies remain limited, but additional procedures have been developed, including the per-oral endoscopic myotomy (POEM). In POEM, a submucosal tunnel is created with an upper endoscope in order to dissect out the longitudinal and circumferential muscle fibers. Once the anatomy is fully dissected, the myotomy can occur which allows for treatment of both the hypertensive LES and the muscles of the esophageal body, if there is comorbid esophageal spasm.
Diagnosis of achalasia, breakdown of subtypes
The standard approach to diagnosing achalasia is by high-resolution esophageal manometry that demonstrates incomplete relaxation at the EGJ along with a lack of organized peristalsis.
There are 3 subtypes of achalasia:
Type I: Also thought of as classical achalasia where there is a lack of peristalsis throughout the esophagus
Type II: The entire body of the esophagus becomes pressurized simultaneously
Type III: There are high amplitude spastic contractions in the esophagus
Treatments based on subtype
Type I: Heller myotomy and pneumatic dilation appear to be equally effective. There have not been head-to-head trials between POEM and pneumatic dilation, but POEM appears to be as effective as Heller myotomy.
Type II: Responds equally well to Heller myotomy and pneumatic dilation
Type III: POEM has demonstrated superior efficacy over other modalities in this patient subtype and should be offered preferentially
As mentioned, effects of botulinum toxin injection are short-lived. For this reason, use is recommended only in patients who are not candidates for definitive therapies because of medical comorbidities or anatomy.
If Heller Myotomy or POEM fail
Patients who have persistent or recurrent symptoms of achalasia with objective findings of incomplete LES relaxation should undergo a second attempt at treatment. Even after a Heller, they are still candidates for POEM or pneumatic dilation.
POEM and reflux
The LES is disrupted with a tunneled myotomy in POEM, but there is often not a concomitant fundoplication performed. This theoretically puts the patient at risk for gastroesophageal reflux which can lead to esophageal stricture formation or even esophageal cancer. The current guidelines recommend performing some form of postprocedural assessment, either objective testing for esophageal acid exposure, long-term acid suppressive therapy (with a proton pump inhibitor), or surveillance upper endoscopy.
These guideline recommendations have had a noticeable effect on the practice of gastroenterology, as providers benefit by having a roadmap to therapy of spastic esophageal disorders and patients can rest assured that their treatment decisions are evidence-based. Guideline support also helps to increase payer coverage for services, which can often be limited for new technologies and techniques (in the case of POEM). While treatment of this condition has greatly improved in recent years, regaining function in late- or end-stage disease remains an elusive goal. Future devices, procedures and techniques will focus on helping this population of patients, along with minimizing the reflux that is a current side effect of LES disruption.