IDDF2022-ABS-0277 Post poem acid reflux – not everything is what it seems!

Background

Incidence of Gastroesophageal reflux (GER) after Peroral Endoscopic Myotomy (POEM) for achalasia cardia ranges from 40–60%, which can be attributed to true acid reflux or other acidification patterns. Identification of acidification pattern require a manual review of a 24-hour pH study as automated analysis overestimates the acid exposure time (AET). Post POEM, Ineffective motility (IEM) on esophageal manometry with acid fermentation on twenty-hour pH study is most commonly seen. IEM is also a common manometric abnormality in patients with GERD. This study aims to determine the true incidence of reflux in Post POEM patients and correlating acidification patterns observed in GERD patients with IEM.

Methods

Prospective observational study of 99 patients with 39 Post POEM, 40 GER with IEM and 20 GER with normal Esophageal motility (NEM) patients were included over 12 months. All patients were subjected to a GERD-Q questionnaire, esophago-gastroscopy, esophageal manometry and 24-hour pH study. All pH tracings were analysed manually by two investigators blinded to the other findings and the mean value of parameters studied were taken. Acid reflux with normal clearance (AR), acid reflux with delayed clearance (ARD), acid fermentation (AF), Stasis of ingested food (SF) and unclassified (UC) were the most common pattern noted in manual analysis.

Results

The mean age was 41 years in post-POEM patients (25 males), the mean age was 40.7 years in GER-IEM group (24 males), and 43.3 years in the GER-NEM group (12 males). Post POEM 56.4% patients had AET >6% on automated analysis in comparison to 30.7% on manual analysis. The predominant acidification pattern in post-POEM patients was AF (43.6%) followed by ARD (23%), AR (10.3%), SF (7.7%) and UC (15.4%). Most common acidification pattern in GER-IEM group was ARD (65%), AR (27.5%) and AF (7.5%). In the GER-NEM group, the predominant pattern was AR (65%), ARD (25%) and AF (10%).

Conclusions

Reflux symptoms after POEM are rarely due to true acidic reflux and commonly due to acid fermentation on manual analysis. The acidification pattern in GERD with IEM is different as compared to the pattern observed in post-POEM patients with IEM.