Newly developed endoscopic retrieval device: funnel-shaped overtube formed by air inflation-deflation

Techniques for endoscopic retrieval require further development. Traditional measures using nets, grasping forceps, and overtubes [1] are sometimes inadequate for retrieval of large, endoscopically resected specimens or sharp foreign bodies with a potential risk of perforation. Although new alternatives include plastic [2], laparoscopic [3], and commercially available bags [4], reliable retrieval of solid gastrointestinal mesenchymal tumors (GIMTs) during endoscopic full-thickness resection is still being investigated. Based on our previously published concept [5], we have developed a novel retrieval device, a funnel-shaped overtube formed by air inflation–deflation (Fuji Systems, Tokyo, Japan). We here report a successful animal experiment in which the device achieved retrieval of press-through package (PTP) sheets and simulated gastric GIMTs ([Video 1]).

Video 1 We described animal experiments in which the developed device was used successfully for retrieving a 4-cm press-through package sheet placed in the esophagus and a handmade 30-mm submucosal tumor model placed in the stomach.

First, a conical wrapping balloon was attached to the leading edge of a silicone overtube ([Fig. 1]). Next, the balloon was inflated with air and pushed forward, after which it was deflated to form a funnel shape, creating a space for retrieval of the relevant object. After the object had been wrapped up, the tip was closed by pulling a thread mounted on the overtube, thus encasing the object to enable retrieval via the mouth or anus, as relevant ([Fig. 2]). A 30-cm device for the esophagus and rectum and a 60-cm device for the stomach have been developed.

Fig. 1 Silicone overtubes in two sizes (60 cm and 35 cm) with conical wrapping balloons attached to their leading edges.

Fig. 2 a, b The balloon is inflated with air and pushed forward. c The balloon is deflated to form a funnel shape, creating a space for retrieving the relevant object. d The tip is closed by pulling the thread mounted on the overtube to wrap up the objects, thus encasing it to retrieve it via the mouth.

In vivo experiments were conducted on three dogs. A 4-cm PTP sheet was placed in the esophagus and a handmade 30-mm submucosal tumor model in the stomach. Using the retrieval device described above, the object was pulled into the balloon using grasping forceps and successfully extracted from the body without complications ([Fig. 3], [Fig. 4]).

Fig. 3 A 4-cm press-through package sheet is placed in the esophagus and pulled into the balloon using grasping forceps.

Fig. 4 a A handmade 30-mm submucosal tumor model is placed in the stomach. b The overtube is guided into the stomach via the endoscope. c The balloon is inflated and then deflated to form a funnel shape, creating a space to retrieve the relevant object. d The object is pulled into the balloon using grasping forceps.

This prototype of a device that we aim to make available commercially may be useful for retrieval of solid gastric tumors or foreign bodies.

Endoscopy_UCTN_Code_TTT_1AO_2AL

Competing interests

The authors declare that they have no conflict of interest.

Acknowledgments

We thank Akihiro Asai, Kazuaki Sato, Hidekazu Nakamura and Fumikazu Watanabe from Fuji Systems Co., Ltd. for their contribution to device mechanism design.
We thank Dr Trish Reynolds, MBBS, FRACP, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.

• References

• 1 Ikehara H, Saito Y, Uraoka T. et al. Specimen retrieval method using a sliding overtube for large colorectal neoplasm following endoscopic submucosal dissection. Endoscopy 2015; 47: E168-E169
• 2 Tanaka S, Toyonaga T, East J. et al. Endoscopic retrieval method using a small grip-seal plastic bag for large colorectal resection specimens after endoscopic submucosal dissection. Endoscopy 2010; 42: E186-E187
• 3 Jacques J, Taibi A, Charrissoux A. et al. Removal of large colorectal lesions resected by endoscopic submucosal dissection using a laparoscopic bag. Endoscopy 2018; 50: E1-E2
• 4 Inoue T, Shichijo S, Nakajima K. Novel protective retrieval device for a large rectal cancer specimen resected by endoscopic submucosal dissection. Dig Endosc 2021; 33: e129-e130
• 5 Kobayashi N, Mori H, Kobara H. et al. Funnel-shaped retrieval device for wrapping large colorectal resection specimens. Endoscopy 2017; 49: E217-E218

Publication History

Article published online:
23 March 2023