Surgical Endoscopy

, Volume 33, Issue 7, pp 2267–2273 | Cite as

Underwater polypectomy without submucosal injection for colorectal lesions ≤ 20 mm in size—a multicenter retrospective observational study

  • A. W. YenEmail author
  • A. Amato
  • S. Cadoni
  • S. Friedland
  • Y. H. Hsieh
  • J. W. Leung
  • M. Liggi
  • J. Sul
  • F. W. Leung



Underwater polypectomy (UWP) of large (≥ 20 mm) colorectal lesions is well described, but reports of UWP for lesions ≤ 20 mm in size, which account for > 95% of polyps encountered in routine clinical practice, are limited. We assessed the feasibility of UWP in routine practice across various sites for colorectal lesions ≤ 20 mm in size.


A multicenter retrospective study was performed on pooled data from nine colonoscopists at 3 U.S., 1 Taiwanese and 2 Italian sites. Outcomes related to UWP on lesions ≤ 20 mm in size were analyzed.


In 117 patients, UWP netted 169 lesions. Polypectomy by hot (HSP, 54%) or cold (CSP, 41%) snare, and cold forceps (CFP, 5%) were performed successfully without endoscopic evidence of residual neoplasia or immediate clinically significant adverse events. The majority (74.6%) were tubular adenomas; 60.9% were from the proximal colon. Histopathologic margins were positive in 4 and unavailable in 26 CSP and 24 HSP specimens. The remainder had negative resection margins on pathologic reports.


UWP for colorectal lesions ≤ 20 mm in routine practice across multiple sites confirms the feasibility and acceptability of this technique. Improvement of resection outcomes by UWP in routine practice deserves further evaluation in a randomized controlled trial.


Polypectomy Underwater Water exchange colonoscopy 



Underwater polypectomy


Water exchange


Hot snare polypectomy


Cold snare polypectomy


Cold forceps polypectomy


Standard deviation


Randomized controlled trial



The project described was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant Number UL1 TR001860. (AWY). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This material is the result of work that was supported by resources from the VA Northern California Health Care System, Sacramento, California, Palo Alto VA, Palo Alto, California, and VA Greater Los Angeles Health System, Los Angeles, California. The contents reported/presented within do not represent the views of the Department of Veterans Affairs or the United States Government.

Compliance with ethical standards


Drs. Yen, Amato, Cadoni, Friedland, Hsieh, J. Leung, Liggi, Sul and F. Leung have no conflicts of interest or financial ties to disclose.


  1. 1.
    Zauber AG, Winawer SJ, O’Brien MJ et al (2012) Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths. N Engl J Med 366:687–696CrossRefGoogle Scholar
  2. 2.
    Leung FW, Amato A, Ell C, Friedland S, Harker JO, Hsieh YH, Leung JW, Mann SK, Paggi S, Pohl J, Radaelli F, Ramirez FC, Siao-Salera RM, Terruzzi V (2012) Water-aided colonoscopy: a systematic review. Gastrointest Endosc 76(3):657–666CrossRefGoogle Scholar
  3. 3.
    Cadoni S, Leung FW (2017) Water-assisted colonoscopy. Curr Treat Options Gastroenterol 15(1):135–154CrossRefGoogle Scholar
  4. 4.
    Binmoeller KF, Weilert F, Shah J et al (2012) “Underwater” EMR without submucosal injection for large sessile colorectal polyps (with video). Gastrointest Endosc 75(5):1086–1091CrossRefGoogle Scholar
  5. 5.
    Curcio G, Granata A, Ligresti D et al (2015) Underwater colorectal EMR: remodeling endoscopic mucosal resection. Gastrointest Endosc 81(5):1238–1242CrossRefGoogle Scholar
  6. 6.
    Uedo N, Nemeth A, Johansson GW et al (2015) Underwater endoscopic mucosal resection of large colorectal lesions. Endoscopy 47:172–174CrossRefGoogle Scholar
  7. 7.
    Schenck RJ, Jahann DA, Patrie JT et al (2017) Underwater endoscopic mucosal resection is associated with fewer recurrences and earlier curative resections compared to conventional endoscopic mucosal resection for large colorectal polyps. Surg Endosc. Google Scholar
  8. 8.
    Amato A, Radaelli F, Spinzi G (2016) Underwater endoscopic mucosal resection: the third way for en bloc resection of colonic lesions? United Eur Gastroenterol J 4(4):595–598CrossRefGoogle Scholar
  9. 9.
    Iishi H, Tatsuta M, Iseki K et al (2000) Endoscopic piecemeal resection with submucosal saline injection of large sessile colorectal polyps. Gastrointest Endosc 51:697–700CrossRefGoogle Scholar
  10. 10.
    Regula J, Wronska E, Polkowski M et al (2003) Argon plasma coagulation after piecemeal polypectomy of sessile colorectal adenomas: long-term follow-up study. Endoscopy 35:212–218CrossRefGoogle Scholar
  11. 11.
    Anderson JM, Goel GA, Cohen H et al (2013) Water infusion distention during colonoscopy is a safe alternative technique to facilitate polypectomy in a “difficult location”. J Interv Gastroenterol 3(4):137–140Google Scholar
  12. 12.
    Ocampo LH, Kunkel DC, Yen A et al (2013) Underwater hot and cold snare polypectomy can be safely executed during water exchange colonoscopy. J Interv Gastroenterol 3(3):104–106CrossRefGoogle Scholar
  13. 13.
    Siau K, Ishaq S, Cadoni S et al (2017) Feasibility and outcomes of underwater endoscopic mucosal resection for ≥ 10 mm colorectal polyps. Surg Endosc. Google Scholar
  14. 14.
    Hsieh YH, Leung FW (2015) A nonpolypoid colorectal neoplasm found during insertion phase of colonoscopy with water exchange: case report and literature review. J Interv Gastroenterol 5(1):38–40CrossRefGoogle Scholar
  15. 15.
    Wildi SM, Schoepfer AM, Vavricka SR et al (2012) Colorectal polypectomy during insertion and withdrawal or only during withdrawal? A randomized controlled trial. Endoscopy 44:1019–1023CrossRefGoogle Scholar
  16. 16.
    Lee CK, Shim JJ, Jang JY (2013) Cold snare polypectomy vs. cold forceps polypectomy using double-biopsy technique for removal of diminutive colorectal polyps: a prospective randomized study. Am J Gastroenterol 108(10):1593–1600CrossRefGoogle Scholar
  17. 17.
    Kim JS, Lee BI, Choi H et al (2015) Cold snare polypectomy versus cold forceps polypectomy for diminutive and small colorectal polyps: a randomized controlled trial. Gastrointest Endosc 81(3):741–747CrossRefGoogle Scholar
  18. 18.
    Singh N, Harrison M, Rex DK (2004) A survey of colonoscopic polypectomy practices among clinical gastroenterologists. Gastrointest Endosc 60(3):414–418CrossRefGoogle Scholar
  19. 19.
    Gómez V, Badillo RJ, Crook JE et al (2015) Diminutive colorectal polyp resection comparing hot and cold snare and cold biopsy forceps polypectomy. Results of a pilot randomized, single-center study (with videos). Endosc Int Open 3(1):E76–E80Google Scholar
  20. 20.
    Pohl H, Srivastava A, Bensen SP et al (2013) Incomplete polyp resection during colonoscopy-results of the complete adenoma resection (CARE) study. Gastroenterology 144(1):74–80.e1CrossRefGoogle Scholar
  21. 21.
    Jia H, Pan Y, Guo X et al (2017) Water exchange method significantly improves adenoma detection rate: a multicenter, randomized controlled trial. Am J Gastroenterol 112(4):568–576CrossRefGoogle Scholar
  22. 22.
    Hsieh YH, Tseng CW, Hu CT et al (2017) Prospective multicenter randomized controlled trial demonstrating water exchange (WE), but not water immersion (WI), significantly increases adenoma detection compared with air insufflation (AI) even in propofol sedated patients. GIE 86(1):192–201Google Scholar
  23. 23.
    Cadoni S, Falt P, Rondonotti E et al (2017) Water exchange for screening colonoscopy increases adenoma detection rate: a multicenter, double-blinded, randomized controlled trial. Endoscopy 49(5):456–467CrossRefGoogle Scholar

Copyright information

© This is a U.S. government work and its text is not subject to copyright protection in the United States; however, its text may be subject to foreign copyright protection 2018

Authors and Affiliations

  • A. W. Yen
    • 1
    • 2
    Email author
  • A. Amato
    • 3
  • S. Cadoni
    • 4
  • S. Friedland
    • 5
    • 6
  • Y. H. Hsieh
    • 7
    • 8
  • J. W. Leung
    • 1
    • 2
  • M. Liggi
    • 4
  • J. Sul
    • 9
    • 10
  • F. W. Leung
    • 10
    • 11
  1. 1.Division of GastroenterologySacramento VA Medical Center, VANCHCSMatherUSA
  2. 2.University of California Davis School of MedicineSacramentoUSA
  3. 3.Division of GastroenterologyValduce HospitalComoItaly
  4. 4.Digestive Endoscopy UnitS. Barbara HospitalIglesiasItaly
  5. 5.Division of GastroenterologyPalo Alto VAMCPalo AltoUSA
  6. 6.Stanford UniversityPalo AltoUSA
  7. 7.Division of GastroenterologyDalin Tzu Chi Hospital, Buddhist Tzu Chi Medical FoundationHualienTaiwan, Republic of China
  8. 8.Tzu Chi UniversityHualienTaiwan, Republic of China
  9. 9.Division of GastroenterologyWest Los Angeles VAMC, VAGLAHSLos AngelesUSA
  10. 10.David Geffen School of Medicine at UCLALos AngelesUSA
  11. 11.Division of GastroenterologyVAGLAHSNorth HillUSA

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