Unveiling the unsealed and modified Zahnker's peroral endoscopic myotomy with open incision. The potential downside of Zahnker's diverticulum traditional treatment with flexible septotomy is high recurrence rate. To achieve complete septotomy, a novel technique called Zahnker's peroral endoscopic myotomy, or Z-POEM, was developed, inspired by the POEM technique for achalasia. Z-POEM has proven to be a safe treatment option with high technical and clinical success rates. Standard Z-POEM technique involves submucosal injection proximal or over the septum, mucosal incision, submucosal tunneling, septotomy or myotomy and closing the mucosotomy via trudoscope clips. The existing Z-POEM technique has its drawbacks, including a consistent recurrence rate, redundant mucosal enlarged diverticula, significant costs due to endoscopic clip usage, and extended procedural durations. To overcome the current limitations, a modified approach called OPEN-Z-POEM was taken. The objectives are to remove the remnant mucosal flap, which is correlated with clinical failure and recurrence, to eliminate the challenges of mucosal closure, and to decrease the length and cost of the procedure. Initially, similar to the modified over the septotomy, Z-POEM was modified over the septum. Submucosal injection is performed over the septum, specifically at the posterior aspect of the septum. After submucosal injection, a mucosal incision is made parallel to the septum axis. This is followed by submucosal dissection performed on the diverticular and esophageal sides. The submucosal dissection on the diverticular side is carried out to just distal to the base of the zincers diverticulum. The muscular layer of the septum is exposed and a myotomy is performed with a scissor-type knife. After the cut, the split between the Zanker's septum and esophageal septum is apparent. A complete myotomy of both diverticular and esophageal muscle is performed, until the base of the prior Zanker's diverticulum is at the same level as the esophagus proper. Afterwards, mucosotomy of the remnant flap is performed distally on the esophageal side to the base of the tunnel. Additionally, mucosotomy is extended at the proximal aspect of the initial mucosal incision, as the persistence of mucosal flap can lead to residual dysphagia. Also, mucosotomy can expose the muscular septum at the base of the diverticulum, allowing complete myotomy. In cases of large diverticula, where food stasis may result in submucosal fibrosis and adhesion of the mucosa to the muscle, the application of mucosal flap resection can effectively ensure the complete removal of the residual muscle tissue. Additionally, in case of a mucosal flap development, it is incised using a snare. Finally, the defect is left open and no clips are used for incision site closure. Leaving the defect open permits the extension of the mucosotomy and removal of any mucosal flaps, and potentially decreasing the recurrence rate. Also, the skip of endoscopic clip usage can substantially reduce the procedure cost and length. As submucosal tunneling is performed and the endoscopist is able to control any additional injury, the risk of perforation is minimal. To refine the open Z-point technique, some key enhancements were employed. Unified Knife A scissor-type knife can be used for all aspects, including the initial mucosal incision, submucosal dissection, myotomy, and mucosotomy. Extension of the myotomy. The myotomy on the esophageal side is extended by an additional 1-2 cm, aiming to prevent recurrence. Optimizing mucosotomy. The mucosotomies extend from the prior septum down to the base of the zincers diverticulum and from the prior septum to the base of the submucosal tunnel, approximately 1-2 cm distal to the exposed esophageal muscle. This aims to remove any residual mucosal flaps. Hemostatic gel application. To expedite healing and prevent bleeding, hemostatic gel is applied at the defect site. Out of 24 patients undergoing Open Z-POEM, technical success was achieved in all cases. The mean procedure duration was impressively short at less than 20 minutes. Clinical success defined by post-procedural Kothari-Haber score of less than 3 was observed in all patients. Median Kothari-Haber score dropped from 5 to 0 over a 4-week follow-up. Two adverse events were observed. One moderate A.E. due to recurrent dysphagia 3 weeks after the procedure due to an esophageal ulcer which resolved without patient therapy. The other one was graded as severe. An esophageal leak, potentially due to CPAP use, which was managed successfully with endoscopic vacuum therapy. In conclusion, we introduce a new modified and simplified Z-POEM approach called Open Z-POEM. Mucosotomy and removal of remnant mucosal flaps in Open Z-POEM could potentially reduce recurrence rate. This simplified method eliminates the challenges of mucosal closure and decreases the cost and length of the procedure. Further optimization, such as the use of scissor-type knife as a sole knife, further simplify and reduce the cost and length of the procedure.

Zahnker's diverticulum

peroral endoscopic myotomy

OPEN-Z-POEM approach

myotomy without endoscopic clips

reducing recurrence rates