Marsupialisation of a tunnel flap for a false oesophageal lumen post peroral endoscopic myotomy

A 68-year-old woman with type 2 achalasia, chronic oesophageal stasis, a thickened mucosal layer, and an Eckardt score of 8 underwent an uncomplicated peroral endoscopic myotomy (POEM; [ Fig. 1 ]). One-month post-POEM, she developed recurrent dysphagia, regurgitation and aspiration. Repeat gastroscopy revealed dehiscence of the oesophageal mucosotomy (tunnel orifice) and formation of a long false lumen ([ Video 1 ]). This was consistent with the original submucosal tunnel, with its wall being a mucosal flap and a healed post-myotomy muscularis propria layer. Fig. 1 Achalasia changes with food contamination and aperistalsis in a . Peroral endoscopic myotomy performed in b , with clip closure following the POEM procedure in c . POEM, peroral endoscopic myotomy. Download Video Mucosotomy dehiscence is found 1 month following a POEM procedure. Marsupialisation of the tunnel mucosal flap is performed with resolution of the patient’s symptoms. POEM, peroral endoscopic myotomy.Video 1 A nasojejunal feeding tube was endoscopically placed for feeding ([ Fig. 2 ]). A computed tomographic scan with oral contrast showed minimal passage of contrast into the distal third of the oesophagus and no mediastinal leak ([ Fig. 3 ]). Despite a conservative approach, repeat gastroscopy after a further 4 weeks demonstrated a persistent false lumen, a dilated proximal oesophagus containing food debris and oesophageal candidiasis ([ Fig. 4 ]). Fig. 2 Formation of a false lumen from the open POEM tract (blue arrow) in a and insertion of a nasojejunal feeding tube in b . POEM, peroral endoscopic myotomy. Fig. 3 A sagittal CT scan with oral contrast showing no mediastinal leak with a dilated oesophagus (red arrow). CT, computed tomography. Fig. 4 A false lumen with a Jagwire passing into the open POEM tract in a and insertion of the Jagwire through the POEM tract into the stomach in b . POEM, peroral endoscopic myotomy. Three months post-POEM procedure, we proceeded with endoscopic marsupialisation of the false lumen. The tunnel was completely epithelialised. There was a small fistula back into the oesophagus at the level of the gastro-oesophageal junction (GOJ). A 0.035-inch Jagwire was placed into the false lumen, through the distal opening and into the stomach ([ Fig. 5 ]). An endoscopic knife was used to dissect the mucosal flap, using the wire as a guide down to the GOJ. Redundant mucosal tissue at the site of the incision was then resected with the EMR technique using a 10 mm hot snare. Repeat gastroscopy 7 months post-POEM showed a healthy appearing scar without evidence of a false lumen. The lower oesophageal sphincter opened easily ([ Video 1 ]). Reassuringly, the patient’s symptoms had resolved following this, with an Eckardt score of 0. Fig. 5 Marsupialisation of the tunnel flap in a and histology of the resection mucosal flap in b , showing dense fibrosis in submucosa with no definite muscularis propria seen. Dehiscence of a submucosal tunnel mucosotomy site leading to a false lumen is a rare complication of POEM [ 1 ] [ 2 ] [ 3 ]. Symptom recurrence post-POEM warrants further endoscopic evaluation. Herein, we have demonstrated a novel technique of guidewire-assisted marsupialisation and eliminated the false lumen and the associated symptoms. Endoscopy_UCTN_Code_TTT_1AQ_2AD_3AZ Publication History Article published online: 15 January 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany