Submucosal dissection of the septum or submucosal tunneling endoscopic septum division: should we wander the free path or follow the tunnel?

We read with great interest the article by Mittal et al. [1], in which they retrospectively studied the practice patterns, techniques, and outcomes of flexible endoscopic myotomy for Zenker’s diverticulum. In their study, they also provided a comparison between the traditional flexible endoscopic myotomy and submucosal dissection of the septum techniques, this being different from the Z-POEM technique. The mean size of the diverticulum was 2.7 cm (0.5 – 7 cm). Submucosal dissection of the septum was used in 24/161 (14.9 %). The technical success rate was the same in the traditional endoscopic myotomy and the submucosal dissection groups (97 % vs. 95.8 %), while the clinical success rate was higher for submucosal dissection of the septum (90.9 % vs. 75.2 %). However, in this study, the adverse events in the submucosal dissection group were higher compared with the traditional group (16.7 % vs. 6.6 %), which is surprising, given that experts in ESD and POEM performed the procedures. It appears possible that this may be because large diverticula were tackled with submucosal dissection of the septum, which might have led to more adverse events. It would be nice if the authors could clarify this for the benefit of readers as this may be giving a false picture of the submucosal dissection of the septum technique. This also suggests the tunneling technique, which allows a controlled and complete septotomy without increasing the chances of adverse events, may be safer, especially in large diverticula, as has been demonstrated in the study of Yang et al. [2].

Recently, preoral endoscopic septotomy (POES), which is essentially similar to submucosal dissection of the septum, has shown 100 % technical and 95 % clinical success with no adverse events; moreover, patients were discharged after 8 hours of observation, making this a daycare procedure [3]. Therefore, a small-sized diverticulum (< 2 cm) can be easily tackled with submucosal dissection of the septum (now named POES), while moderate- (3 – 5 cm) and large-sized (> 5 cm) diverticula will benefit from submucosal tunneling endoscopic septum division (ST-ESD/Z-POEM), which shows good efficacy and safety [2] [3].

Publication History

Article published online:
29 March 2021

• References

• 1 Mittal C, Diehl D, Draganov P. et al. Practice patterns, techniques, and outcomes of flexible endoscopic myotomy for Zenker’s diverticulum: a retrospective multicenter study. Endoscopy 2021; 53
• 2 Yang J, Novak S, Ujiki M. et al. An international study on the use of peroral endoscopic myotomy in the management of Zenker's diverticulum. Gastrointest Endosc 2020; 91: 163-168
• 3 Repici A, Spadaccini M, Belletrutti PJ. et al. Peroral endoscopic septotomy for short-septum Zenker's diverticulum. Endoscopy 2020; 52: 563-568