Knocking stent release technique to deploy lumen-apposing metal stents during endoscopic ultrasound-guided gallbladder drainage

Sep 30, 2026

Uploaded by moss~

Knocking stent release technique is proposed for deploying lumen-apposing metal stents (LAMS) during endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) in patients unsuitable for surgical resection. The paper explains why smaller target lesion diameters may lead to reduced anchoring force with 10–15 mm LAMS compared with 20 mm devices, increasing the risk of stent dislocation when using scope-pulling deployment. Procedural steps include duodenal identification, water-filling delivery advancement with electrocautery dilation, sequential distal and proximal flange release, and controlled scope right-angle rotation and clockwise turning to visualize and safely “knock” the stent delivery system out without adverse events.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Knocking stent release technique for EUS-GBD

Rationale and risk of stent dislocation

Procedural steps and scope positioning

Conclusion

Article published online: 2026-01-08 Knocking stent release technique to deploy lumen-apposing metalstents during endoscopic ultrasound-guided gallbladder drainage Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumenapposing metal stent (LAMS; Hot AXIOS, Boston Scientific, Tokyo, Japan) can be performed in patients with contraindications for surgical resection [1–4] . EUSGBD can be performed either from the stomach or the duodenum. Although no randomized trial has compared the optimal drainage route, a recent meta-analysis suggests that the duodenal approach may be safer. Compared with the drainage of walled-off necrosis or a pancreatic pseudocyst, the diameter of the target lesion is usually smaller in EUSGBD. Therefore, a 10- or 15-mm-diameter LAMS is generally selected. However, compared with a 20-mm-diameter LAMS, the anchoring force may be lower. As a result, if stent deployment is performed using the scope-pulling technique, stent dislocation may occur as a complication ( ▶ Fig.1) . To overcome this adverse event, we usually deploy the LAMS using the “knocking stent release technique.”Technical tips for the knocking stent release technique are presented. An echoendoscope was inserted into the duodenum, and the gallbladder was identified. To prevent double mucosal penetration, the delivery system was advanced to the duodenal wall using the water-filling technique. Then, the delivery system insertion with electrocautery dilation was performed, with successful insertion into the gallbladder. Subsequently, the distal flange was released, and the delivery system was pulled back to the proximal gallbladder wall. Finally, the proximal flange was released using the intra-scope channel release technique ( ▶ Fig.2) . Next, if the stent release was performed by pulling the echoendoscope, stent dislocation can occur; therefore, first, the right angle of the echoendoscope was applied ( ▶ Fig.3), and the scope was then rotated clockwise ▶Fig. 1 If stent deployment is performed using the scope-pulling technique, stent dislocation may occur as a complication. ▶Fig.2 The proximal flange is released using the intra-scope channel release technique. ▶Fig.3 The right angle of the echoendoscope is applied. ( ▶ Fig.4) . By doing so, the LAMS was partially visualized. Finally, the stent delivery system was knocking, and the stent was finally extracted from the echoendoscope without any adverse events ( ▶ Fig.5 ; ▶Video 1) . In conclusion, the knocking stent release technique to deploy a LAMS during EUSGBD might be useful. Endoscopy_UCTN_Code_TTT_ 1AS_ 2AH Contributors ʼ Statement Takeshi Ogura: Writing – original draft, Writing – review & editing. Junichi Nakamura: Writing – review & editing. Takafumi Kanadani: Writing – review & editing. Kimi Bessho: Writing – review & editing. Hiroki Nishikawa: Writing – review & editing. Ogura Takeshi et al. Knocking stent release… Endoscopy 2026; 58: E21–E22 | © 2026. The Author(s) . E21 ▶Fig.4 The scope is rotated clockwise. ▶Fig.5 The stent delivery system is knocking, and the stent is extracted from the echoendoscope. Conflict of Interest The authors declare that they have no conflict of interest. The authors Takeshi Ogura1,2,3, Junichi Nakamura1,3, Takafumi Kanadani1,3, Kimi Bessho1,3, Hiroki Nishikawa3 1 Pancreatobiliary Advanced Medical Center, Osaka Medical and Pharmaceutical University Hospital, Osaka, Japan 2 Endoscopy Center, Osaka Medical and Pharmaceutical University Hospital, Osaka, Japan 3 2nd Department of Internal Medicine, Osaka Medical and Pharmaceutical University, Osaka, Japan Corresponding author Takeshi Ogura, MD, PhD, FJGESPancreatobiliary Advanced Medical Center, Osaka Medical and Pharmaceutical University Hospital, 2-7 Daigakuchou, Takatsukishi, Osaka 569-8686, Japan oguratakeshi041 [1@yahoo.co.jp](1@yahoo.co.jp) Video 1 The stent delivery system is knocking, and the stent is extracted from the echoendoscope.

FAQs

Why can stent dislocation occur during EUS-GBD with the scope-pulling technique?

Because smaller lesion diameters in EUS-GBD often lead to selecting 10–15 mm LAMS, which may provide lower anchoring force than 20 mm LAMS; this can increase the risk of stent dislocation when stent deployment is done by scope pulling.

What are the key steps of the “knocking stent release technique”?

An echoendoscope is placed in the duodenum and the gallbladder is identified. The delivery system is advanced using the water-filling technique to prevent double mucosal penetration, followed by electrocautery dilation insertion into the gallbladder. Then the distal flange is released, the system is pulled back to the proximal wall, and the proximal flange is released via the intra-scope channel. Finally, the stent delivery system is knocked and the stent is extracted from the echoendoscope under controlled scope rotation.

How does the technique reduce the risk of dislocation when releasing the stent?

It avoids stent release driven by pulling the echoendoscope; instead, the echoendoscope right angle is applied and the scope is rotated clockwise for partial visualization, allowing safe “knocking” deployment without adverse events.

Sep 30, 2026

Uploaded by moss~