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. 2025 Oct 10;6(1):e70221.
doi: 10.1002/deo2.70221. eCollection 2026 Apr.

Gel-immersion Endoscopic Submucosal Dissection for Superficial Colorectal Neoplasms: A Retrospective Study Comparing Conventional Endoscopic Submucosal Dissection

Kenji Yamauchi  1 , Tomoki Inaba  1 , Takeshi Morimoto  2 , Hugh Shunsuke Colvin  1 , Akira Nakanishi  1 , Shigenao Ishikawa  1 , Masaki Wato  1
Affiliations

Gel-immersion Endoscopic Submucosal Dissection for Superficial Colorectal Neoplasms: A Retrospective Study Comparing Conventional Endoscopic Submucosal Dissection

Kenji Yamauchi et al. DEN Open. .

Abstract

Objectives: Gel-immersion endoscopy offers benefits such as buoyancy, traction, and a clear visual field without gas insufflation. While some case reports have described colorectal gel-immersion endoscopic submucosal dissection (Gi-ESD), there have been no consecutive case series. This study aimed to clarify the usefulness of Gi-ESD.

Methods: This single-center retrospective cohort study included consecutive patients with colorectal neoplasms who underwent ESD. Gi-ESD was defined as mucosal incision and submucosal dissection performed under clear gel. The primary outcomes were en bloc and histologic R0 resection rates, whereas the secondary outcomes were procedure time, dissection speed, and adverse events.

Results: Among 260 ESD cases, 29 and 231 were in the Gi-ESD and conventional ESD groups, respectively. Gel was used for submerged or poorly accessible lesions. The Gi-ESD group had a significantly larger tumor diameter (25 mm vs. 18 mm, p = 0.001), a higher rate of lesions in the cecum or ascending colon (55.2% vs. 31.2%, p = 0.01), and more lesions with ESD difficulty factors (24.1% vs. 9.5%, p < 0.05). There were no significant differences in the en bloc resection (100% vs. 99.1%), histologic R0 resection (96.6% vs. 88.7%), or adverse events. In the propensity score-matched cohort, the histologic R0 resection rate was significantly higher in the Gi-ESD group (100% vs. 82.6%, p = 0.045). Procedure time was significantly longer in the Gi-ESD group (45 vs. 29.5 min, p = 0.006), with no significant difference in dissection speed (14.9 vs. 19.2 mm2/min, p = 0.19).

Conclusion: Gi-ESD may be an alternative approach for treating submerged gravity-side or poorly approached colorectal lesions.

Keywords: colon neoplasms; endoscopic mucosal resection; endoscopic surgery; gravitation; immersion.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

FIGURE 1
FIGURE 1
(a) Laterally spreading granular tumor (LST‐G) with a diameter of 50 mm was located on the ascending colon. (b) The downward side of the lesion was easily submerged. (c) Mucosal incision under the gel. (d) Creation of a submucosal pocket under the gel. (e) Opening the gravity side of the pocket using buoyancy traction. (f) Opening the remaining upward side under CO2 insufflation using gravity traction. (g) Mucosal defect without perforation. (h) En bloc R0 resection.
FIGURE 2
FIGURE 2
Study flowchart. ESD, endoscopic submucosal dissection.
See this image and copyright information in PMC

References

    1. Iacopini F., Saito Y., Bella A., et al., “Colorectal Endoscopic Submucosal Dissection: Predictors and Neoplasm‐related Gradients of Difficulty,” Endoscopy International Open 5 (2017): E839–846. - PMC - PubMed
    1. Yano T., Nemoto D., Ono K., et al., “Gel Immersion Endoscopy: A Novel Method to Secure the Visual Field During Endoscopy in Bleeding Patients (With videos),” Gastrointestinal Endoscopy 83 (2016): 809–811. - PubMed
    1. Yano T., Takezawa T., Hashimoto K., et al., “Gel Immersion Endoscopy: Innovation in Securing the Visual Field—Clinical Experience With 265 Consecutive Procedures,” Endoscopy International Open 9 (2021): E1123–1127. - PMC - PubMed
    1. Maruyama T., Murakami T., Akazawa Y., Shibuya T., and Nagahara A., “A Case of Improved Visibility With Gel Immersion in the Presence of Ongoing Bleeding During Colorectal Endoscopic Submucosal Dissection,” VideoGIE 6 (2021): 478–480. - PMC - PubMed
    1. Ashizawa H., Hotta K., Imai K., et al., “Efficacy and Safety of Gel Immersion Endoscopic Mucosal Resection for Non‐pedunculated Colorectal Polyps,” Life 13 (2023): 711. - PMC - PubMed

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