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

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.