Underwater endoscopic mucosal resection using a detachable snare for a pedunculated lesion located in the greater curvature of the upper gastric body

The usefulness of underwater endoscopic mucosal resection (UEMR) has been shown for colorectal and duodenal lesions [1] [2] as well as gastric lesions, especially those located in the greater curvature of the gastric body [3] [4]. As it is difficult to approach and dissect such gastric lesions using endoscopic submucosal dissection, UEMR is sometimes chosen as an alternative treatment.

A 56-year-old woman was referred to our hospital for detailed investigation of a gastric lesion. Esophagogastroduodenoscopy revealed a 20-mm pedunculated lesion in the greater curvature of the upper gastric body. The lesion was reddish with a diffuse depression on the surface ([Fig. 1 a, b]). Narrow-band imaging revealed a regular surface pattern without a clear demarcation line ([Fig. 1 c]). As the patient desired endoscopic resection in order to obtain an accurate diagnosis, we attempted polypectomy. When the stomach was filled with air, it was difficult to approach the lesion and recognize the base of the stalk ([Fig. 2 a]). However, when the lumen was filled with normal saline instead, water immersion enabled the lesion to float, and we could identify the base ([Fig. 2 b]). Moreover, we could compress the lesion stalk using a detachable snare (Endoloop; Olympus Corp., Ltd, Tokyo, Japan) while fully visualizing the stalk ([Fig. 3 a]). We achieved en bloc resection using a 25-mm snare (SnareMaster Plus; Olympus Corp.) ([Fig. 3 b]). The procedure was completed within 10 minutes without adverse events ([Fig. 3 c], [Video 1]). Pathological analysis of the resected specimen showed collections of dilated ducts similar to multicyst formation in the submucosa ([Fig. 3 d]), and the dilated ducts were compartmentalized in smooth muscle fibers. These findings were compatible with a hamartomatous inverted polyp [5]. When a detachable snare is used to excise a pedunculated lesion located in the greater curvature of the upper gastric body, UEMR can be effective.

Fig. 1 Endoscopic views. a Esophagogastroduodenoscopy revealed a 20-mm pedunculated lesion located in the greater curvature of the upper gastric body. b The lesion was reddish with a diffuse depression on the surface. c Narrow-band imaging showed a regular surface pattern without a clear demarcation line.

Fig. 2 Endoscopic views. a When the stomach was filled with air, it was difficult to approach the lesion and recognize the base of the stalk. b Water immersion enabled the lesion to float, and we were able to identify the base.

Fig. 3 Resection of the lesion. a We were able to compress the lesion stalk using a detachable snare, with full visualization of the stalk. b Snaring the base of the lesion using a 25-mm snare. c No apparent residual tumor was seen around the resected lesion. d Histological image of the resected specimen.

Video 1 Underwater endoscopic mucosal resection was performed as an alternative treatment for a pedunculated lesion located in the greater curvature of the upper gastric body.

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Competing interests

The authors declare that they have no conflict of interest.

Acknowledgments

We thank Jane Charbonneau, DVM, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.

• References

• 1 Uedo N, Nemeth A, Johansson GW. et al. Underwater endoscopic mucosal resection of large colorectal lesions. Endoscopy 2015; 47: 172-174
• 2 Yamasaki Y, Uedo N, Takeuchi Y. et al. Underwater endoscopic mucosal resection for superficial nonampullary duodenal adenomas. Endoscopy 2018; 50: 154-158
• 3 Yamamoto S, Takeuchi Y, Uedo N. et al. Underwater endoscopic mucosal resection for gastric neoplasms. Endosc Int Open 2022; 10: E1155-E1158
• 4 Iwagami H, Kanesaka T, Ishihara R. et al. Underwater endoscopic mucosal resection for remaining early gastric cancer after endoscopic submucosal dissection. Endoscopy 2019; 51: E229-E230
• 5 Aoki M, Yoshida M, Saikawa Y. et al. Diagnosis and treatment of a gastric hamartomatous inverted polyp: report of a case. Surg Today 2004; 34: 532-536

Publication History

Article published online:
09 March 2023