Reply to Ishaq et al.

We appreciate the interest of Ishaq et al. in our study on the impact of prior treatment on the outcomes of Zenker’s peroral endoscopic myotomy (Z-POEM) [1].

The adverse event rate in our study was comparable with the pooled 11 % rate reported for flexible endoscopic septum division (FESD) [2]. Furthermore, the first meta-analysis on Z-POEM data reported an adverse event rate of 6 % [3]. Most mucosotomies can be closed intraprocedurally with through-the-scope clips. These are largely inconsequential and not regarded as true adverse events by many experts. As with any new procedure, the rate of adverse events is expected to improve as endoscopists gain experience with the procedure. The authors commented on the perforation risk owing to the absence of longitudinal muscle and serosal layers. We disagree with this suggestion. We now have more than 10 years of experience with esophageal POEM, during which time the risks of leakage, perforation, and infection have been extremely low, despite full-thickness myotomy. The principle of third-space endoscopy relies on breaching the muscle layer followed by secure mucosal closure.

We agree that a longer duration of follow-up is warranted. The premise of Z-POEM is that it theoretically decreases the risk of symptom recurrence as it permits complete visualization and dissection of the septum. Long-term follow-up of patients is needed to validate this premise. The rate of recurrence after standard flexible endoscopic diverticulotomy is significant, being as high as 35 % during mid- to long-term follow-up [4].

Overall, we have been performing Z-POEM for the last 4 years and the results have been consistently good. Recurrence is uncommon and, with experience, mucosotomies and leakage become rare. Traditionally, Z-POEM is performed using a proximal incision approach. Recently, most operators have changed to an over-the-septum approach. This latter approach provides a wider working space that renders mucosal closure much easier. We suspect the leakage rate will also decrease as this approach becomes more widely used. We remain optimistic that Z-POEM is here to stay, while acknowledging that randomized trials are needed to compare its efficacy and safety with other standard techniques.

Publication History

Article published online:
24 June 2021

• References

• 1 Sanaei O, Ichkhanian Y, Mondragón OVH. et al. Impact of prior treatment on feasibility and outcomes of Zenkerʼs peroral endoscopic myotomy (Z-POEM). Endoscopy 2020;
• 2 Ishaq S, Hassan C, Antonello A. et al. Flexible endoscopic treatment for Zenker’s diverticulum: a systematic review and meta-analysis. Gastrointest Endosc 2016; 83: 1076-1089.e5
• 3 Kamal F, Khan MA, Lee-Smith W. et al. Peroral endoscopic myotomy is a safe and feasible option in management of esophageal diverticula: systematic review and meta-analysis. Dig Dis Sci 2020;
• 4 Yuan Y, Zhao YF, Hu Y. et al. Surgical treatment of Zenker’s diverticulum. Dig. Surg 2013; 30: 207-218