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Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) using a 22-gauge needle and a 0.018-inch guidewire is well suited for bile duct puncture and initial guidewire insertion [1] [2]; however, subsequent tract dilation and stent delivery remain technically challenging. Although dilation devices compatible with a 0.018-inch guidewire have been reported [3] [4], tract dilation carries a potential risk of bile leakage. Furthermore, because no catheter specifically designed for a 0.018-inch guidewire has been available, switching to a stiff guidewire generally requires multiple device exchanges. This additional step may prolong the procedure and increase the risk of bile leakage [5].

A novel uneven double-lumen cannula (UDLC; PIOLAX, Tokyo, Japan) features an ultra-tapered tip designed for a 0.018-inch guidewire and a side lumen for a 0.035-inch guidewire, with a maximum diameter of 6-Fr ([Fig. 1]). This design enables effective bile aspiration while allowing one-step insertion of an additional stiff guidewire without device exchange, thereby improving procedural safety and stability while minimizing tract dilation.

Fig. 1 A novel uneven double-lumen cannula (UDLC); PIOLAX, Tokyo, Japan) featuring an ultra-tapered tip designed for a 0.018-inch guidewire and a side lumen compatible with a 0.035-inch guidewire.

In the present case of EUS-HGS performed in a patient with hilar biliary obstruction and previously placed fully covered multi-hole metallic stents ([Fig. 2] and [Fig. 3]), a 0.018-inch guidewire (J-wire Premier Non-marker, J-Mit Co., Ltd, Kyoto, Japan) could not be advanced across the stents. Because of the short insertion length, a 0.018-inch guidewire alone was insufficient to provide adequate stability for stent delivery. Consequently, the novel UDLC was inserted over the 0.018-inch guidewire, enabling bile aspiration followed by insertion of an additional 0.035-inch stiff guidewire. Finally, a dedicated plastic stent (7-Fr, 10 cm, Through & Pass Type IT, Gadelius Medical, Tokyo, Japan) was successfully deployed without additional tract dilation ([Fig. 4]; [Video 1]).

Fig. 2 Initial drainage for hilar biliary obstruction caused by unresectable gallbladder cancer. a Cholangiography reveals a bismuth type IIIa stricture. b Fully covered multi-hole metallic stents are deployed in the right anterior and posterior branches.Fig. 3 Computed tomography findings before endoscopic ultrasonography-guided hepaticogastrostomy. a Markedly dilation of the intrahepatic bile duct in the left lobe. b Gallbladder cancer with invasion of the perihilar bile duct.Fig. 4 Endoscopic ultrasound-guided hepaticogastrostomy. a The intrahepatic bile duct (B3) is punctured with a 22-gauge needle, followed by a 0.018-inch guidewire. b The novel uneven double-lumen cannula is advanced smoothly, and bile aspiration is performed. c A 0.035-inch guidewire is inserted through the side lumen. d A 7-Fr dedicated plastic stent is successfully deployed.Download VideoEUS-guided hepaticogastrostomy using a novel uneven double-lumen cannula enabling bile aspiration and insertion of an additional stiff guidewire when advancement across pre-existing metallic stents is not feasible. EUS, endoscopic ultrasound.Video 1

To the best of our knowledge, this is the first report of EUS-HGS using the novel UDLC designed for a 0.018-inch guidewire. This device addresses the limitation associated with 22-gauge needle access during EUS-HGS.

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Article published online:
13 February 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).

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