Stent-in-stent deployment for malignant hilar obstruction using multi-hole stent can prevent tumor ingrowth during 6-month cholangioscopic follow-up

Malignant hilar biliary obstruction (MHBO) can be treated by bilateral uncovered self-expandable metal stent (SEMS) deployment using a stent-in-stent (SIS) technique [1]. Recently, patient survival has been prolonged as a result of recent improvements in systemic chemotherapy, including immune checkpoint inhibitors; therefore, prolonged stent patency is necessary. As there is a risk of tumor ingrowth with an uncovered SEMS, stent patency might not be good. A fully covered SEMS (FCSEMS) can prevent tumor ingrowth, and stent patency might therefore be longer than with an uncovered SEMS. However, because an FCSEMS can obstruct a bile duct branch, FCSEMS deployment for MHBO using the SIS technique may not be feasible. Recently, an FCSEMS with side holes (HANAROSTENT Biliary Multi-hole NEO; M.I. Tech Co., Ltd, Pyeongtaek, South Korea) has become available (MHSEMS) ([Fig. 1]). This stent was designed to prevent stent migration through small tissue ingrowths that form in the multiple small (1.8 mm) side holes along the covering membrane [2] [3]. In addition, through this hole, SIS deployment can be performed ([Fig. 2]). We present a case of successful SIS deployment using the new MHSEMS and describe cholangioscopic findings on long-term follow-up.

Fig. 1 The fully covered self-expandable metal stent with side holes (HANAROSTENT Biliary Multi-hole NEO; M.I. Tech Co., Ltd, Pyeongtaek, South Korea).

Fig. 2 The fully covered self-expandable metal stent with side holes was designed to prevent stent migration through small tissue ingrowths that form in the multiple small (1.8 mm) side holes along the covering membrane; stent-in-stent deployment can also be performed through these holes.

A 55-year-old man was admitted to our hospital due to unresectable MHBO. Before systemic chemotherapy, biliary drainage was attempted. After successful biliary cannulation and contrast medium injection, bile duct obstruction was observed. First, the stent delivery system for an MHSEMS was inserted into the left bile duct and successfully deployed. Next, the guidewire was inserted into the right hepatic bile duct. Finally, an MHSEMS was deployed at the right hepatic bile duct using the SIS technique ([Fig. 3]).

Fig. 3 A fully covered self-expandable metal stent with side holes was deployed at the right hepatic bile duct using the stent-in-stent technique.

Recurrent biliary obstruction was seen 6 months later. An endoscopic retrograde cholangiopancreatography catheter was inserted into the stents, and contrast medium was injected. Although neither bile stent was obstructed, lower bile duct stenosis was observed. A cholangioscope was inserted to evaluate the condition of the stents. Tumor ingrowth had been completely prevented ([Fig. 4]), but lower bile duct obstruction was observed and considered to be due to lateral tumor spread ([Fig. 5], [Video 1]). Therefore, an FCSEMS was deployed for the lower biliary stricture. After this reintervention, recurrent biliary obstruction was not observed until the patient’s death (4 months later).

Fig. 4 Tumor ingrowth was completely prevented.

Fig. 5 Lower bile duct obstruction was observed and considered to be due to lateral tumor spread.

Bile duct obstruction by the fully covered self-expandable metal stent with side holes was not observed.Video 1

In conclusion, the SIS technique using an MHSEMS for MHBO may achieve longer stent patency by preventing tumor ingrowth. A randomized trial comparing uncovered SEMS and MHSEMS is needed.

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Conflict of Interest

The authors declare that they have no conflict of interest.

• References

• 1 Lee TH, Moon JH, Choi JH. et al. Prospective comparison of endoscopic bilateral stent-in-stent versus stent-by-stent deployment for inoperable advanced malignant hilar biliary stricture. Gastrointest Endosc 2019; 90: 222-230
• 2 Kobayashi M. Development of a biliary multi-hole self-expandable metallic stent for bile tract diseases: a case report. World J Clin Cases 2019; 7: 1323-1328
• 3 Kulpatcharapong S, Piyachaturawat P, Mekaroonkamol P. et al. Efficacy of multi-hole self-expandable metal stent compared to fully covered and uncovered self-expandable metal stents in patients with unresectable malignant distal biliary obstruction: a propensity analysis. Surg Endosc 2024; 38: 212-221

Publication History

Article published online:
05 February 2025