Zenker's diverticulum: advancing beyond the tunnel

Background and Aims: Zenker's diverticulum (ZD) is attributed to a poorly compliant cricopharyngeus muscle, and the mainstay of treatment is a cricopharyngeal myotomy. We present a video series summarizing endoscopic treatment options for ZD and related conditions. Methods: We review the rationale and key technique for various endoscopic treatment modalities for ZD, cricopharyngeal bar, and other esophageal diverticula. Results: Standard flexible endoscopic cricopharyngeal myotomy involves the division of the common wall or septum of the ZD, aiming for complete transection of the cricopharyngeus. However, recurrence rates are high, likely owing to incomplete myotomy. Zenker's peroral endoscopic myotomy (Z-POEM) uses a proximal submucosal tunnel to provide direct visualization of the cricopharyngeus and septum, allowing confirmation of complete myotomy. We demonstrate an over-the-septum modification to simplify the technique. Submucosal fibrosis, commonly seen in patients with prior treatment, limits submucosal dissection. We present a hybrid technique to overcome this, whereby a traditional septotomy is performed until submucosal tissue is visualized. The intact mucosal flap after Z-POEM in a large ZD may contribute to residual dysphagia. We propose Z-POEM with mucosotomy for large ZD. Finally, we demonstrate modifications for treatment of other esophageal diseases, including cricopharyngeal bar and non-Zenker's esophageal diverticula. Conclusion: Endoscopic treatment options for ZD and related conditions are rapidly expanding. With careful tailoring to individual patient characteristics, our expanding arsenal of options allows effective and safe treatment of a broad spectrum of patients.