Achalasia is a primary esophageal motility disorder characterized by impaired lower esophageal sphincter relaxation and absent peristalsis. Although no treatment is curative, interventions aim to reduce esophagogastric junction obstruction and improve symptoms. Pneumatic dilation, laparoscopic Heller myotomy and per-oral endoscopic myotomy (POEM) have comparable efficacy in type I and II achalasia, whereas POEM is preferred for type III. Long-term outcomes of both POEM and Heller myotomy demonstrate symptom control rates between 80–90%. Post-POEM gastroesophageal reflux (GERD) is common, with esophagitis reported in up to 65% of patients, though severe disease is less frequent and often improves over time. Regular surveillance is recommended to detect silent esophagitis and guide management. Our aim was to evaluate long-term clinical efficacy of POEM and GERD-related outcomes in a real-world cohort.

This retrospective single-center study included all patients undergoing POEM for achalasia at a tertiary Portuguese referral center between January 2017 and November 2023, with ≥24 months of follow-up. All procedures were performed by a single experienced endoscopist. The primary outcome was clinical success, defined as a post-POEM Eckardt score ≤3 without additional intervention. Secondary outcomes included perioperative adverse events (AEs), post-POEM GERD assessed through patient-reported symptoms, long-term proton pump inhibitor (PPI) therapy and endoscopic findings. AEs were classified according to the AGREE system. 

A total of 143 patients underwent technically successful POEM. Of these, 113 patients had ≥24 months of follow-up. Median age was 55 years (range 17–81), and 57 patients were female (50.4%). Achalasia types were: 72 type II, 28 type I and 13 type III. Only one significant post-procedure AE occurred (aspiration pneumonia requiring ICU admission, Grade IV). Clinical response at 1 year was 97.3% (n=110), with long-term clinical success in 88.5% (n=100) with a median follow-up of 44 months (range 21–96). Thirteen patients experienced symptomatic recurrence at a median of 24 months (range 0–48), four underwent re-POEM and two underwent endoscopic dilation with sustained success, while two are awaiting endoscopic retreatment. Higher pre-POEM Eckardt scores were significantly associated with recurrence (p=0.027), with a median of 9 points in the recurrence group versus 6 points in responders. No significant association was observed between clinical success and achalasia type, age, gender, previous treatment or myotomy approach.

Regarding GERD, 29 patients reported frequent or daily reflux symptoms at some point during follow-up, but only 15 (13%) remained symptomatic at last evaluation, all responding to PPI therapy. Long-term PPI therapy (>6 months) was required in 95 patients (84%), and 79 (70%) remained on daily PPI at last follow-up. First post-procedure endoscopy (median 7 months) was available for 85 patients: esophagitis was found in 42 (49%), including severe reflux esophagitis in 13% (10 LA-C, 1 LA-D) and ischemic ulcers in five patients. Last endoscopy (median 32 months, n=70) revealed esophagitis in 31, severe in only 1 patient (1.4%, LA-C). Eleven patients were on PPI at the time of last endoscopy, one twice daily. At least one patient had documented refractory reflux esophagitis (LA-B despite twice-daily PPI). No patient required additional endoscopic or surgical intervention for GERD. Reported symptomatic reflux was significantly associated with clinical failure (p=0.017), with 62% of patients with long-term failure reporting symptoms (without severe esophagitis in endoscopy) versus 21% of responders. No associations were found between symptoms or severe esophagitis and age, gender, achalasia type, diabetes, alcohol use, smoking, BMI or myotomy approach.

POEM is a safe and highly effective treatment for achalasia, achieving excellent long-term clinical success. Post-POEM GERD is common but usually manageable with long-term PPI therapy, and no patient in our cohort required additional interventions. Higher reported reflux symptoms among patients with clinical failure may reflect overlapping symptomatology between uncontrolled achalasia and GERD, highlighting the importance of monitoring and managing reflux symptoms during follow-up.