Gel immersion endoscopy-facilitated endoscopic mucosal resection of a superficial nonampullary duodenal epithelial tumor: a novel approach

Video

Video 1

Gel immersion endoscopy-facilitated endoscopic mucosal resection of a superficial nonampullary duodenal epithelial tumor.

Endoscopic resection of superficial nonampullary duodenal epithelial tumors (SNADETs) is considered highly difficult because of the technical challenges posed by the complex anatomic features of the duodenum.1, 2, 3 Underwater endoscopic mucosal resection (UEMR), a water immersion method, results in high resection and low adverse event rates.1, 2, 3 However, continuously maintaining water in the lumen is difficult.

A novel gelatinous liquid was developed to secure the visual field during endoscopy (Fig. 1). This gelatinous liquid is composed of xanthan gum, locust bean gum, and glycerin. The viscoelastic properties of the liquid enable continuous filling of the lumen and prevent mixing with fresh blood or feces, resulting in a favorable space for endoscopic visualization and treatment. In addition, the viscosity of the gelatinous liquid slows bleeding and leads to easy hemostasis. Yano et al⁴ reported that using gelatinous liquid during endoscopy resulted in a favorable visual field; they named this method gel immersion endoscopy. Moreover, Miyamoto et al⁵ reported that gel immersion endoscopy was useful in endoscopic ultrasonography observation. Although it is mainly used for the hemostasis of GI bleeding and EUS observation, its use in endoscopic mucosal resection has not been reported previously.

Figure 1.

Gelatinous liquid.

In these cases, we completely resected an SNADET using gelatinous liquid to fill the lumen and secure a favorable visual field. We have named this novel method gel immersion endoscopic resection (GIER).

Superficial 7- and 5-mm elevated lesions in the opposite side of the superior duodenal angle were resected using GIER (Figs. 2A and 3A). Butylscopolamine was administered as an antispasmodic agent. First, we gently immersed the lesions in gelatinous liquid using a syringe to secure a favorable visual field (Figs. 2B and 3B). We injected 90 mL of gelatinous liquid for the former lesion and 60 mL for the latter lesion. Similar to UEMR, endoscopic ultrasonography revealed that the lesions floated in the gelatinous liquid–filled lumen, whereas the muscular layer remained flat (Fig. 4). The lesions were captured easily using a 10-mm snare under gelatinous liquid immersion, resulting in en bloc resection (Figs. 2C and D, 3C and D). The current was passed using a high-frequency generator (VIO300D; Erbe Elektromedizin, Tübingen, Germany). VIO300D was used with the following settings: dry-cut mode (effect 4, 40 W) for mucosal resection. Prophylactic clip closure was performed after resection. The former lesion was pathologically diagnosed as intramucosal cancer with negative margins (Fig. 5A and B), and the latter lesion was diagnosed as adenoma with negative margins (Fig. 6A and B).

Figure 2.

Case 1 (the former lesion). A, Superficial 7-mm elevated lesions in the opposite side of the superior duodenal angle. B, The lesion was immersed in gelatinous liquid to secure a favorable visual field. C, The resection site showed no residual lesion. D, The specimen size was 9 mm × 9 mm, and tumor size was 7 mm × 7 mm.

Figure 3.

Case 2 (the latter lesion). A, Superficial 5-mm elevated lesions in the opposite side of the superior duodenal angle. B, The lesion was immersed in gelatinous liquid to secure a favorable visual field. C, The resection site showed no residual lesion. D, The specimen size was 10 mm × 9 mm, and tumor size was 5 mm × 5 mm.

Figure 4.

Endoscopic ultrasonography image of the lesions floating in the gelatinous liquid–filled lumen, whereas the muscular layer remained flat (arrows).

Figure 5.

Pathological findings of case 1 (the former lesion). A, Pathologically diagnosed intramucosal cancer with negative margins (H&E, orig. mag. ×100). B, Pathologically diagnosed intramucosal cancer with negative margins (H&E, orig. mag. ×400).

Figure 6.

Pathological findings of case 1 (the latter lesion). A, Pathologically diagnosed adenoma with negative margins (H&E, orig. mag. ×40). B, Pathologically diagnosed adenoma with negative margins (H&E, orig. mag. ×100).

Case 2 had a superficial 10-mm elevated and depressed lesion in the second part of the duodenum (Fig. 7A and B). We injected 200 mL of gelatinous liquid (Fig. 7C). The lesion was easy to capture using a 15-mm snare under gelatinous liquid immersion, resulting in en bloc resection (Fig. 7D, E, and F). The specimen size was 26 mm × 16 mm (Fig. 7E and F). The diathermy setting was used and prophylactic clip closure was performed similar to that performed for case 1. The lesion was pathologically diagnosed as adenoma with negative margins (Fig. 8A and B). This case suggested that GIER could resect lesions measuring over 20 mm.

Figure 7.

Case 2. A, B, Superficial 10-mm elevated and depressed lesion in the second part of the duodenum. C, The lesion was immersed in gelatinous liquid to secure a favorable visual field. D, The resection site showed no residual lesion. E, F, The specimen size was 26 mm × 16 mm, and tumor size was 10 mm × 8 mm.

Figure 8.

Pathological findings of case 2. A, Pathologically diagnosed adenoma with negative margins (H&E, orig. mag. ×40). B, Pathologically diagnosed adenoma with negative margins (H&E, orig. mag. ×100).

Although we have proposed GIER as a novel replacement method for UEMR, it has a drawback with regard to cost-effectiveness. The gelatinous liquid costs 2000 yen per 200 mL, which is more expensive than water.

In conclusion, gelatinous liquid enables continuous filling of the lumen and secures a favorable visual field. These characteristics result in an easy and safe procedure. Therefore, we highly recommend GIER for high-difficulty lesions such as SNADETs (Video 1, available online at www.VideoGIE.org).

Disclosure

All authors disclosed no financial relationships.

Supplementary data

Video 1

Gel immersion endoscopy-facilitated endoscopic mucosal resection of a superficial nonampullary duodenal epithelial tumor.