.
The procedure was clinically successful and relieved chest pain in most patients, reported Mouen A. Khashab, MD, director of therapeutic endoscopy at Johns Hopkins Hospital in Baltimore.
POEM was introduced in 2008 as a less invasive alternative to laparoscopic Heller myotomy. During the procedure, submucosal tunneling is performed through the lower esophageal sphincter to the gastric cardia, thereby weakening the lower esophageal sphincter to allow passage of food.
POEM is clinically successful in 80%-90% of patients with achalasia. Although the procedure is regarded as safe and effective for achalasia, it has not been thoroughly researched for treatment of other esophageal motility disorders, including junction outflow obstruction (EGJOO), jackhammer esophagus (JE), or esophagogastric distal esophageal spasm (DES). EGJOO is similar to achalasia, but with peristalsis and a mean integrated relaxation pressure (IRP) greater than 15 mm Hg. Both JE and DES are spastic esophageal disorders. Patients with JE exhibit extreme esophageal hypercontractility, whereas patients with DES have a normal mean IRP and at least 20% premature contractions.
“The role POEM plays in management of these disorders is not clear, mainly due to scarcity of studies on this topic,” the authors wrote in Endoscopy International Open. “A previous multicenter study investigated the role of POEM in 73 patients with spastic esophageal disorders. However, the vast majority of patients (n = 54) in that study had type III (spastic) achalasia.” Since therapies such as botulinum toxin injections and calcium channel blockers are ineffective for many patients with nonachalasia esophageal motility disorders, “POEM is potentially an ideal treatment.”
The international, multicenter study involved 11 treatment centers and 50 patients. Patients with JE (n = 18), EGJOO (n = 15), and DES (n = 17) were included, each diagnosed according to the Chicago classification of esophageal motility disorders. Patients with type III achalasia were excluded.
Outcomes included technical success (completion of myotomy) and clinical success (Eckardt score at least 3 and symptom improvement). Prior to the procedure, the mean Eckardt score was 6.9 and chest pain was reported by almost three-quarters of the patients (72%).
Technical success was achieved in all patients. Myotomy thickness varied between cases; approximately half had a selective inner circular myotomy (48%), slightly less had a full-thickness myotomy (44%), and several were undefined (8%). Mean esophageal myotomy length was 12.5 cm and mean gastric myotomy length was 2.5 cm. Mean procedure time was approximately 90 minutes. Median duration of hospital stay was 2 days.
Nine adverse events (AEs) occurred in 8 patients, including submucosal hematoma, aspiration pneumonia, inadvertent mucosotomy, postprocedure pain, esophageal leak, bleed, and symptomatic capno-thorax/peritoneum.
“Although AEs occurred in 18% of patients,” the authors noted, “55.6% were rated as mild and 44.4% as moderate with no severe events. Most AEs can be managed intraprocedurally.”
Median follow-up time was approximately 8 months, during which 42 patients (87.5%) achieved clinical success, with many dramatically improved; over half of the patients (52%) had Eckardt scores of 0 or 1. From the group of patients who had chest pain prior to the procedure, 87% had resolution of chest pain. Although reflux developed in almost a quarter of the patients (22.2%), this was successfully managed with proton pump inhibitors in all instances. Most patients (82.9%) who underwent postoperative manometry had resolution of preoperative abnormalities.
Subgroup analysis was also performed. Clinical success was achieved in 94.1% of patients with DES, 93.3% of patients with EGJOO, and 75.0% with JE. Collectively, the spastic disorders (DES/JE) had a lower numerical response than EGJOO. However, the authors noted that “the difference was not statistically significant (P = .41), likely a type II error due to the relatively small number of included patients.” In all subgroups, postprocedural mean Eckardt scores decreased to less than 2. Patients with EGJOO were most likely to achieve Eckardt scores of 0 or 1. AEs were similar between subgroups.
“Remarkably, chest pain improved in more than 85% of patients,” the authors wrote. “Chest pain is frequently the major presenting symptom in these disorders and is difficult to treat.”
“It is important to mention that a long esophageal myotomy is essential to ensure that proximal esophageal spasms are effectively covered and treated,” the authors wrote. “Mean length of esophageal myotomy in patients with DES and JE in the current study was about 14 cm, which is more than twice the length of a typical endoscopic or surgical myotomy performed in achalasia patients.”
Even with the need for an extended myotomy, “results from the current study along with published data suggest POEM as an effective technique” for nonachalasia esophageal motility disorders, the authors concluded.
Since retrospective studies are inherently limited by design, the authors encouraged randomized trials to clarify the primary role of POEM in the management of nonachalasia esophageal motility disorders.
The authors reported compensation from Olympus, Boston Scientific, and Cook Medical.
SOURCE: Khashab MA et al. Endosc Int Open. 2018 Aug 10. doi: 10.1055/a-0625-6288.