Systematic Reviews
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Oct 16, 2022; 14(10): 608-615
Published online Oct 16, 2022. doi: 10.4253/wjge.v14.i10.608
Water-jet vs traditional triangular tip knife in peroral endoscopic myotomy for esophageal dysmotility: A systemic review and meta-analysis
Yuliya Belopolsky, Srinivas R Puli
Yuliya Belopolsky, Srinivas R Puli, Division of Gastroenterology and Hepatology, University of Illinois College of Medicine at Peoria, Peoria, IL 61605, United States
Author contributions: Belopolsky Y and Puli SR contributed equally and substantially to the conception and design of the work, analysis, acquisition, interpretation of data for the work, and drafting the work and revising for important intellectual content; Belopolsky Y and Puli SR agree to be accountable for all aspects of work in ensuring questions related to accuracy and integrity of any part of the work are appropriately investigated and resolved; all authors wrote, read and approved the final manuscript.
Conflict-of-interest statement: There is no conflict of interest from any of all authors.
PRISMA 2009 Checklist statement: All authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Yuliya Belopolsky, MD, Academic Fellow, Division of Gastroenterology and Hepatology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL 61605, United States.
Received: April 6, 2022
Peer-review started: April 6, 2022
First decision: May 31, 2022
Revised: July 3, 2022
Accepted: September 6, 2022
Article in press: September 6, 2022
Published online: October 16, 2022

Peroral endoscopic myotomy is an increasingly used less invasive modality to treat esophageal dysmotility. Recently, triangular tip knife with integrated water jet function has been introduced to mitigate multiple instrument exchanges.


To compare traditional triangular tip knife and water jet knife in terms of procedural success, duration, instrument exchanges, coagulation forceps use, and adverse events.


We conducted a systemic review and meta-analysis with two authors independently in electronic databases (PubMed, Embase, and Cochrane Library) from inception through May 2021. In addition, we conducted a relevant search by Reference Citation Analysis (RCA) ( A fixed-effects model was used to calculate weighted mean, odds ratio (OR), and confidence intervals (CI).


We included 7 studies involving 558 patients. Triangular knife and water jet knife were similar in odds of procedural success with ratio of 4.78 (95%CI = 0.22-102.47) and odds of clinical success with ratio of 0.93 (95%CI = 0.29-2.97), respectively. Water jet knife had fewer instrument exchanges compared to triangular knife (2.21, 95%CI = 1.98-2.45 vs 11.9, 95%CI = 11.15-12.70) and usage of coagulation forceps (1.75, 95%CI = 1.52-1.97 vs 2.63, 95%CI = 2.37-2.89). Adverse events were higher in triangular knife group (OR: 2.30, 95%CI = 1.35-3.95).


Peroral endoscopic myotomy using water jet knife is comparable in terms of procedural success to triangular tip knife. Water jet knife also required shorter procedural duration, less instrument exchanges, coagulation devices, and overall adverse events.

Keywords: Gastroenterology, Endoscopy gastrointestinal, Esophageal motility disorders, Water jet knife, Dysmotility

Core Tip: Peroral endoscopic myotomy (POEM) has gained traction due to its novel technique of preserving the mucosal layer while working in the submucosa and minimizing risk of leakage of contents into the mediastinum. It hails comparable efficacy and safety data to the standard surgical therapy of laparoscopic Heller myotomy in short term follow up studies. The major steps of POEM are similar among centers, including small mucosal incision, submucosal tunneling, myotomy, and mucosal closure. Within these individual steps, many tools and variations exist to achieve the result. Recently, an innovative water-jet integrated triangular tip knife (WJ) has been devised in order to improve procedural time with less instrument changes, as well as minimize adverse events. There have been several studies comparing the conventional triangular tip knife and WJ and suggesting that WJ can achieve similar clinical and procedural success rate, but with lower adverse effects, instrument changes, and intra-procedural coagulation devices. This is the first meta-analysis to compare the two instruments.