Gel Immersion Endoscopic Submucosal Dissection Using a Scissor-type Knife for Superficial Non-ampullary Duodenal Epithelial Tumors

Abstract

Objectives: This study aimed to compare the short-term therapeutic outcomes between conventional endoscopic submucosal dissection (C-ESD) and gel immersion ESD (GI-ESD) for superficial non-ampullary duodenal epithelial tumors (SNADETs).

Methods: A retrospective analysis was conducted on patients with SNADETs who underwent C-ESD or GI-ESD between June 2016 and May 2024. To reduce proficiency bias, the first 50 cases per endoscopist were excluded. C-ESD was performed using a scissor-type knife under CO₂ insufflation, while GI-ESD was performed using the same knife under gel immersion. Primary outcomes included en bloc and R0 resection rates; secondary outcomes were resection time, adverse events, and inflammatory response.

Results: Overall, 51 C-ESD and 49 GI-ESD procedures were analyzed. Both groups achieved 100% en bloc resection. R0 resection rates were comparable (C-ESD: 92.6%, GI-ESD: 90.2%, p = 0.661). Muscle layer exposure was significantly lower in the GI-ESD group (1.9%) than in the C-ESD group (16.7%, p = 0.032). The mean white blood cell count was also significantly lower in the GI-ESD group (p = 0.038). The incidence of adverse events in the C-ESD and GI-ESD groups was 5.6% and 1.9%, respectively (p = 0.627). However, no cases of perforation or aspiration were observed in the GI-ESD group.

Conclusions: GI-ESD is a safe and effective alternative to conventional ESD for SNADETs, offering comparable resection outcomes and low risk of adverse events with a reduced risk of muscle layer exposure.

Keywords: adverse event | endoscopic submucosal dissection | gel immersion | scissor‐type knife | superficial non‐ampullary duodenal epithelial tumor.

FIGURE 1

GI‐ESD using a Clutch Cutter for a SNADET: (a) A superficial elevated lesion on the lateral wall of the descending portion. (b) Magnifying blue laser imaging (M‐BLI) shows an irregular microstructure. (c) Submucosal dissection was performed using the pocket‐creation method. (d) ESD was performed without complications. (e) Complete closure was achieved with the underwater clip closure method using 18 reopenable clips. (f) En‐bloc resection was achieved (well‐differentiated adenocarcinoma, 45 mm, pTis, Ly0, V0). SNADET, superficial non‐ampullary duodenal epithelial tumor; ESD, endoscopic submucosal dissection.

FIGURE 2

Shema of conventional endoscopic submucosal dissection (C‐ESD) and gel immersion ESD (GI‐ESD): (a) To approach a lesion on the descending portion, the endoscope must be forced into a curved position with CO₂ insufflation during C‐ESD. (b) GI‐ESD allows the scope to be maintained in a straight position when approaching the lesion due to deflation of the stomach. (c) During C‐ESD, the narrow submucosal space after the mucosal incision makes it difficult for the endoscope to enter the submucosal layer. (d) During GI‐ESD, the submucosal space is widened because the tumor floats into the lumen due to the buoyancy effect. (e) It is difficult to secure a clear visual field when intraoperative bleeding occurs during C‐ESD. (f) Gel immersion maintains a clear visual field because bleeding does not immediately diffuse due to the high viscosity.

FIGURE 3

Definition of muscle exposure after endoscopic submucosal dissection (ESD): (a) Muscle layer exposure, positive. The coagulated muscle layer in the mucosal defect is visible. (b) Muscle layer exposure is negative. The muscle layer is not visible in the mucosal defect.

FIGURE 4

Flowchart of the study population.

FIGURE 5

Inflammatory response after C‐ESD and GI‐ESD: (a) white blood cell (WBC) count and (b) C‐reactive protein (CRP) level. C‐ESD, conventional endoscopic submucosal dissection; GI‐ESD, gel immersion endoscopic submucosal dissection.