The therapeutic endoscopic procedure per-oral endoscopic myotomy (POEM) is safe and has a high clinical success rate at 2 years in patients with the rare esophageal motility disorder achalasia, according to results of the longest follow-up study to date.

The research team said that achalasia is characterized by the loss of enteric neurons, which results in impaired relaxation of the lower esophageal sphincter and absence of esophageal peristalsis.

Current treatment options have included botulinum toxin injection, endoscopic pneumatic dilation, or laparoscopic Heller’s myotomy.

The newer procedure, called POEM, is based on a technique of submucosal endoscopy and endoscopic myotomy. However, while short-term studies have shown it to be safe and effective for achalasia, long-term data have been limited.

“As achalasia is a chronic disease with a risk of recurrence of symptoms after treatment, long-term efficacy, rather than short-term data, is important for decision making surrounding the optimal therapeutic modalities,” wrote the investigators, led by Saowanee Ngamruengphong, MD, of Johns Hopkins Hospital, Baltimore (Gastrointest Endosc. 2016. doi: 10.1016/j.gie.2016.09.017) .

The study involved 205 patients with achalasia from 10 centers in the United States, Europe, and Asia. Patients were included in the study if they had at least 2 years of follow-up data available.

Results showed that the overall clinical success – defined by a decrease in Eckardt score to 3 or lower – for the procedure was 91% at 2 years. The Eckardt score (maximum 12) is a composite measure of frequency of symptoms and severity of weight loss.

Overall, 18 patients (8.8%) were considered to have clinical failure (Eckardt score greater than 3) after POEM.

A history of prior pneumatic dilation was associated with long-term treatment failure (odds ratio, 3.41; 95% confidence interval, 1.25-9.23).

The researchers noted that the therapeutic success of POEM decreased over time as the clinical success rate of the procedure at 6 months’ follow-up had been 98%.

This is consistent with findings from other studies and also with other procedures such as Heller myotomy and pneumatic dilation.

“After POEM or other standard therapies, patients with achalasia require ongoing follow-up to assess recurrent symptoms with additional evaluation and treatment when indicated,” they wrote.

In terms of safety, the researchers reported procedure-related adverse events in 8.2% of patients, with one patient requiring surgical intervention.

Abnormal esophageal acid exposure and reflux esophagitis were also documented in 37.5% and 18% of patients, respectively.

Multivariate analysis revealed that full-thickness myotomy was independently associated with postoperative reflux esophagitis (adjusted OR, 3.99; 95% CI, 1.16-13.68; P = .002).

The authors noted that while reflux was common after POEM, almost all patients could be successfully treated with proton pump inhibitors.

“Prospective randomized studies comparing POEM and current standard therapy are awaited, but in the meantime, it can be considered an effective alternative option for patients with achalasia where expertise is available,” they concluded.