Tetra-side-by-side technique using a multi-hole self-expandable metal stent with a 5.9-Fr stent delivery system - clinical technical tips

Sep 30, 2026

Multiple stent placement may be required for high-grade hepatic hilar obstruction, where side-by-side (SBS) or stent-in-stent (SIS) strategies can be used after uncovered self-expandable metal stent deployment. However, tumor ingrowth can limit stent patency. A fully covered approach prevents ingrowth but may cause cystic duct or bile duct branch obstruction and does not support SIS. This report describes technical tips for the tetra-SBS method using a 5.9-Fr fine-gauge multi-hole self-expandable metal stent (MHCSEMS), and demonstrates successful insertion and deployment without adverse events in a clinical case.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Tetra-side-by-side technique overview

Rationale and device features

Clinical case and deployment steps

Outcome and conclusion

Article published online: 2026-01-08 Tetra-side-by-side technique using a multi-hole self-expandable metalstent with a 5.9-Fr stent delivery system Multiple stent deployment is sometimes necessary in cases of high-grade hepatic hilar obstruction. When uncovered selfexpandable metal stent deployment is performed, the side-by-side (SBS) orstent-in-stent (SIS) technique can be selected [1,2] . However, stent patency might be limited due to the common complication of tumor ingrowth. Alternatively, a fully covered SEMS (FCSEMS) has the benefit of preventing tumor ingrowth, but it does not allow SIS and carries the risk of cystic duct or bile duct branch obstruction. A multi-hole selfexpandable metal stent with a fine-gaugestent delivery system (MHCSEMS; HANAROSTENT Biliary Multi-hole Benefit; M.I. Tech Co., Ltd., Pyeongtaek, South Korea) that overcomes these limitations has become available ( ▶ Fig.1) . The stent prevents stent migration via small tissue ingrowth that occurs in the multiple small (1.8-mm) side holes along the covering membrane. The side holes also act to prevent cystic duct or bile branch obstruction. Because the stent delivery system is only 5.9Fr, the system can be advanced easily and smoothly. Here, we report technical tips for the tetra-SBS technique using an MHSEMS for hilar obstruction. A 77-year-old man underwent plasticstent deployment in the anterior and posterior bile ducts, and antegrade FCSEMS deployment in the left hepatic bile duct with hepaticogastrostomy following an unsuccessful left hepatic bile duct approach under endoscopic retrograde cholangiopancreatography guidance. Due to stent obstruction, endoscopic revision was attempted. First, the right-sided plastic stents and the FCSEMS were removed, and guidewires were deployed into the left, anterior, and posterior bile ducts ( ▶ Fig.2) . Hilar obstruction was observed on cholangiography. Astent delivery system was successfully inserted into the posterior bile duct ▶Fig. 1 The multi-hole self-expandable metal stent with a 5.9-Fr stent delivery system (MHCSEMS; HANAROSTENT Biliary Multi-hole Benefit; M.I. Tech Co., Ltd, Pyeongtaek, South Korea) . ▶Fig.2 Guidewires are deployed into the left, anterior, and posterior bile ducts. ▶Fig.4 Successful stent deployment using an MHCSEMS for the anterior bile duct. MHCSEMS, multi-hole self-expandable metal stent. ▶Fig.3 The MHCSEMS delivery system is inserted and deployed successfully. MHCSEMS, multi-hole self-expandable metal stent. ▶Fig.5 Successful stent deployment using an MHCSEMS for the left bile duct. MHCSEMS, multi-hole self-expandable metal stent. E34 Ogura Takeshi et al. Tetra-side-by-side technique using… Endoscopy 2026; 58: E34–E35 | © 2026. The Author(s) . Video 1 Tetra-side-by-side technique using a multi-hole self-expandable metal stent with a 5 . 9-Fr stent delivery system is performed. ( ▶ Fig.3), followed by successful stent deployment into the anterior bile duct ( ▶ Fig.4) . The fine-gauge stent delivery system was easily inserted into the left bile duct ( ▶ Fig.5 ; ▶Video 1) without any adverse events. In conclusion, the tetra-SBS technique using an MHCSEMS with a fine-gaugestent delivery system appears suitable for the insertion of a stent delivery system and prevents cystic or bile duct branch obstruction. Endoscopy_UCTN_Code_TTT_ 1AR_ 2AZ Conflict of Interest | The authors declare that they have no conflict of interest.
The authors | | --- | | Takeshi Ogura1,2, Jun Matsuno2 , Takafumi Kanadani2, Junichi Nakamura2, Hiroki Nishikawa2
1 Endoscopy Center, Osaka Medical and Pharmaceutical University Hospital, Osaka, Japan
2 2nd Department of Internal Medicine, Osaka Medical and Pharmaceutical University, Osaka, Japan
Corresponding author | Takeshi Ogura, MD, PhD, FJGES Endoscopy Center, Osaka Medical and Pharmaceutical University Hospital, 2-7 Daigakuchou, Takatsukishi, Osaka 569-8686, Japan oguratakeshi041 [1@yahoo.co.jp](1@yahoo.co.jp) Referen

FAQs

Why are multiple stents sometimes needed for hepatic hilar obstruction?

Multiple stent deployment may be necessary in cases of high-grade hepatic hilar obstruction to achieve adequate biliary drainage.

What are the limitations of uncovered SEMS and fully covered SEMS approaches?

Uncovered self-expandable metal stents can use SBS or SIS, but stent patency may be limited by tumor ingrowth. Fully covered SEMS prevent tumor ingrowth but cannot support SIS and carry risks of cystic duct or bile duct branch obstruction.

How does the multi-hole self-expandable metal stent (MHCSEMS) address those limitations?

The stent prevents migration through small tissue ingrowth in multiple side holes, and the side holes help prevent cystic duct or bile branch obstruction. Its 5.9-Fr fine-gauge delivery system enables smooth advancement into the bile ducts.

Sep 30, 2026

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