Introduction
Peroral endoscopic myotomy (POEM) may result in a distended distal esophagus, referred to as a blown-out myotomy (BOM). It has been suggested that BOM may have functional and symptomatic consequences. The aim of this study was to investigate the prevalence, risk factors and associated symptoms of BOM after achalasia treatment using a clinical trial dataset (POEMA trial).
Aims & Methods
We analyzed data of newly diagnosed symptomatic achalasia patients (based on an Eckardt greater than 3) in our center who participated in a previous randomized controlled trial in which they were randomly allocated to undergo treatment with POEM or pneumatic dilation (PD). Follow-up was planned at 3 months, 1, 2 and 5 years after treatment and included an esophagram, endoscopy, HRM and symptom questionnaires. We defined a BOM as a >50% increase in esophageal diameter at its widest point in the distal esophagus between the lower esophageal sphincter and 5 cm above.
Results
In total 74 patients were treated in our center, of which 5-year follow-up data was available in 55 patients (32 (58%) patients randomized to POEM, 23 (42%) PD). During the 5-year follow-up a part of the patients received retreatment which resulted in 15 (27%) patients that were treated with PD only and 40 (73%) patients treated with POEM or PD + POEM. In the group initially treated with POEM the incidence of BOM increased from 11.5% (4/38) at three months, 21.1% (8/38) at 1-year, 27.8% (10/36) at 2-years and 31.3% (10/32). A BOM was seen in none of the patients treated with PD alone and 32.5% of the patients ever treated with POEM at 5-year follow-up (p=0.011). There were no differences in baseline LES-resting pressure (25.8 (21.8-34.0) mmHg vs 36.0 (26.4-46.3) mmHg, p=0.168) and baseline IRP-4 (24.7 (17.8-36.5) mmHg vs 31.0 (21.7-38.7) mmHg, p=0.240) between patients ever treated with POEM with or without a BOM. Achalasia subtype type did seem to be a risk factor for the occurrence of a BOM in our cohort, as BOM occurred in 25% (2/8) of type 1, 27% (7/26) of type II and 67% (4/6) of type III achalasia (p=0.152). Patients that developed a BOM had higher total Eckardt score and Eckardt regurgitation component compared to patients that underwent POEM without BOM development (3 (2.75-3.25) vs 2 (1.75-3) p=0.032) and (1 (0.75-1 vs 0 (0-1) p=0.041). The barium column surface (barium height * width) was not significantly different at 1 minute (12.2 (8.4-19.1) cm2 vs 10.5 (3.0-17.6) cm2, p=0.345) or at 5 minutes (10.8 (2.7-18.9) cm2 vs 7.2 (0-12.8) cm2, p=0.197) in patients with or without a BOM. In addition, at 5-year follow-up no significant difference was seen in IRP-4 (13.4 (9.1-18.8) mmHg vs 12.1 (8.5-16.7) mmHg, p=0.377) and LES-resting rate (18.1 (14.3-26.0) mmHg vs 22.3 (13.7-29.8) mmHg, p=0.642) in patients with or without a BOM. POEM patients more often report reflux symptoms (based on GERDQ > 8) when a BOM is present compared to when no BOM is present (85% (11/13) vs 46% (2/16), p=0.023)). BOM did not have an effect on presence of reflux esophagitis (54% (7/13) vs 41% (11/27), p=0.329) or PPI use (54% (7/13) vs 44% (12/27), p=0.413). Acid exposure time (measured at 1-year follow-up) was significantly higher in patients with a BOM compared to no BOM ((24.5% (8-47)) vs 6% (1.2-18.7), p=0.027).
Conclusion
a BOM was seen in one third of patients treated with POEM regardless of achalasia subtype, resulting in a higher acid exposure, more reflux symptoms and symptoms of regurgitation.
Disclosure
PF received consultancy fees from Olympus and Cook Endoscopy.
JEP received research funding from National Institutes of Health National Institute of Diabetes and Digestive and Kidney Disease, and declares the following financial relationships with a commercial interest: consulting for Medtronic, ethicon, diversatek, Ironwood, Phathom, and Neurogastrx; patent held or filed (FLIP-AI) for Medtronic; and speaking and teaching for Medtronic and ethicon.
AJB received research funding from Nutricia, Dr Falk Pharma, Thelial, SST and Bayer and received speaker or consulting fees from Laborie, Medtronic, Dr Falk Pharma, Alimentiv, Sanofi/Regeneron, and AstraZeneca.
All other authors declare no competing interests.