BACKGROUND AND AIMS: Zenker's peroral endoscopic myotomy (Z-POEM) has demonstrated excellent technical and clinical success. However, the remnant mucosal flap can result in symptom recurrence. In addition, mucosal closure can be technically challenging. This study introduces Open Z-POEM (OZ-POEM), a modified approach that allows additional mucosotomy by eliminating mucosal closure. METHODS: This is a retrospective observational study, in which patients with Zenker's diverticulum who underwent OZ-POEM were included from December 2022 to May 2024. The primary outcome was clinical success (Kothari-Haber Score <
3). The secondary outcomes included technical success, recurrence, and adverse events. RESULTS: A total of 53 patients (mean age 74±10 years, 69.8% males) underwent OZ-POEM in two centers (USA and India), with a mean diverticulum size of 26±14 mm. OZ-POEM was technically successful in all patients, with a mean procedure time of 19±6 minutes. There was a significant decrease in the median (IQR) Kothari-Haber score from 7 (5-8) to 1 (0-1) (p <
0.01) after a median follow-up of 23.5 weeks. Two patients (3.8%) experienced symptomatic recurrence after a median of 28.5 weeks, requiring re-intervention. One patient (1.9%) had a late ulcer resolved with medical therapy, and another (1.9%) an early leak treated with vacuum therapy, with all asymptomatic at follow-up. CONCLUSIONS: OZ-POEM is a novel, feasible, and safe procedure with a short procedure time, eliminating the need for incision site closure. The incorporation of extensive mucosotomy is the likely reason behind the very low recurrence rate (3.8%)
however, prospective comparative studies are necessary to support these findings.