Use of the Scissor-Type Knife During the Peroral Endoscopy Myotomy Procedure for the Treatment of Achalasia.

Peroral endoscopic myotomy (POEM) is one of the first-line treatment modalities along with pneumatic dilation and Heller myotomy for patients with achalasia. Endoscopists, especially trainees during the learning phase, commonly face difficulty in tissue plane dissection and selective myotomy while working near the esophagogastric junction, with increased risks of inadvertent injury, unexpected bleeding, and inadequate myotomy. To minimize the technical difficulty and improve the safety of POEM, we describe a protocol for using a scissor-type knife for the main steps of POEM, including mucosal incision, submucosal tunneling, myotomy, and hemostasis. The standard techniques used with the scissor-type knife involve grasping the target tissue, and then dissection or coagulation. The confirmation of the cutting line after grasping improves the accuracy and reliability of dissection, which is particularly useful for the selective myotomy of the internal circular muscle. Meanwhile, the scissor-type knife provides enhanced hemostatic capability and enables hemostasis and pre-coagulation without the device exchange for hemostatic forceps. Evaluation of the clinical outcomes in three patients who successfully received POEM using the scissor-type knife revealed no perioperative adverse events. At the 3-month follow-up, all patients achieved clinical success with postoperative Eckardt scores ranging from 0 to 1. In conclusion, the use of a scissor-type knife could minimize the technical difficulty and improve the safety of the POEM procedures, which may be suitable for trainees during the learning phase.