Endoscopic radiofrequency ablation for ingrowth occlusion after bilateral metal stent placement for malignant hilar biliary obstruction: a prospective pilot study

Published:October 08, 2022DOI:

      Background and Aims

      Endoscopic biliary radiofrequency ablation (RFA) may be an option for the treatment of ingrowth occlusion after self-expandable metal stent (SEMS) deployment; however, its utility remains uncertain. This study aimed to examine the feasibility of RFA for the palliation of ingrowth after bilateral SEMS placement in patients with malignant hilar biliary obstruction.


      This prospective, single-center, pilot study enrolled 30 patients who met the eligibility criteria between April 2020 and March 2022. Study outcomes were technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events (AEs) besides RBO associated with RFA for ingrowth occlusion. Furthermore, factors predictive of clinical success were evaluated.


      Technical and clinical success rates were 93.3% (28/30) and 71.4% (20/28), respectively. The rates of early and late AEs were 6.7% (2/30) and 10.0% (2/20), respectively. The incidence rate of RBO after RFA was 45.0% (9/20), and the median time to RBO was 163 days. Multivariate analysis of the factors affecting clinical success revealed a positive association between the recanalization diameter on the ingrown part within the SEMS (odds ratio, 1.13; 95% confidence interval, 1.01-1.26; P = .038). The calculated optimal cutoff for the ratio of the recanalization diameter to the SEMS diameter for predicting clinical success was 51.1%.


      Endoscopic biliary RFA elicited promising results, with good long-term stent patency and without the requirement of any additional stent placement, for the palliation of ingrowth occlusion after bilateral SEMS placement. However, the clinical success rate was insufficient, necessitating improvements in the future. (Clinical trial registration number: UMIN000040154.)


      AE (adverse event), MHBO (malignant hilar biliary obstruction), PS (plastic stent), RBO (recurrent biliary obstruction), RFA (radiofrequency ablation), RI (reintervention), SEMS (self-expandable metal stent), SIS (stent-in-stent)
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        • Lee T.H.
        • Moon J.H.
        • Choi J.H.
        • 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
        • Dumonceau J.M.
        • Tringali A.
        • Papanikolaou I.S.
        • et al.
        Endoscopic biliary stenting: indications, choice of stents, and results: European Society of Gastrointestinal Endoscopy (ESGE) clinical guideline—updated October 2017.
        Endoscopy. 2018; 50: 910-930
        • Lee T.H.
        • Kim T.H.
        • Moon J.H.
        • et al.
        Bilateral versus unilateral placement of metal stents for inoperable high-grade malignant hilar biliary strictures: a multicenter, prospective, randomized study (with video).
        Gastrointest Endosc. 2017; 86: 817-827
        • Xia M.X.
        • Pan Y.L.
        • Cai X.B.
        • et al.
        Comparison of endoscopic bilateral metal stent drainage with plastic stents in the palliation of unresectable hilar biliary malignant strictures: large multicenter study.
        Dig Endosc. 2021; 33: 179-189
        • Lee T.H.
        • Moon J.H.
        • Park S.H.
        Biliary stenting for hilar malignant biliary obstruction.
        Dig Endosc. 2020; 32: 275-286
        • Kato H.
        • Matsumoto K.
        • Okada H.
        Recent advances regarding endoscopic biliary drainage for unresectable malignant hilar biliary obstruction.
        DEN Open. 2021; 2: e33
        • Inoue T.
        • Naitoh I.
        • Suzuki Y.
        • et al.
        Multi-center study of endoscopic revision after side-by-side metal stent placement for malignant hilar biliary obstruction.
        Dig Endosc. 2021; 33: 807-814
        • Lee T.H.
        • Jang S.I.
        • Moon J.H.
        • et al.
        Endoscopic revision efficacy after clinically successful bilateral metal stenting for advanced malignant hilar obstruction.
        J Gastroenterol Hepatol. 2020; 35: 2248-2255
        • Inoue T.
        • Yoneda M.
        Updated evidence on the clinical impact of endoscopic radiofrequency ablation in the treatment of malignant biliary obstruction.
        Dig Endosc. 2022; 34: 345-358
        • Inoue T.
        • Ibusuki M.
        • Kitano R.
        • et al.
        Endobiliary radiofrequency ablation combined with bilateral metal stent placement for malignant hilar biliary obstruction.
        Endoscopy. 2020; 52: 595-599
        • Kang H.
        • Han S.Y.
        • Cho J.H.
        • et al.
        Efficacy and safety of temperature-controlled intraductal radiofrequency ablation in advanced malignant hilar biliary obstruction: a pilot multicenter randomized comparative trial.
        J Hepatobiliary Pancreat Sci. 2022; (;29:469-78)
        • Pai M.
        • Valek V.
        • Tomas A.
        • et al.
        Percutaneous intraductal radiofrequency ablation for clearance of occluded metal stent in malignant biliary obstruction: feasibility and early results.
        Cardiovasc Intervent Radiol. 2014; 37: 235-240
        • Nayar M.K.
        • Oppong K.W.
        • Bekkali N.L.H.
        • et al.
        Novel temperature-controlled RFA probe for treatment of blocked metal biliary stents in patients with pancreaticobiliary cancers: initial experience.
        Endosc Int Open. 2018; 6: E513-E517
        • Inoue T.
        • Kitano R.
        • Yoneda M.
        Endobiliary radiofrequency ablation for ingrowth occlusion after bilateral metal stent placement in patients with malignant hilar biliary obstruction.
        Endosc Int Open. 2021; 9: E907-E908
        • Inoue T.
        • Kitano R.
        • Yoneda M.
        Troubleshooting of reinterventions after stent-by-stent placement for malignant hilar biliary obstruction (with videos).
        Hepatobiliary Pancreat Dis Int. 2022; (;21:500-2)
        • Isayama H.
        • Hamada T.
        • Yasuda I.
        • et al.
        Tokyo criteria 2014 for transpapillary biliary stenting.
        Dig Endosc. 2015; 27: 259-264
        • Cotton P.B.
        • Eisen G.M.
        • Aabakken L.
        • et al.
        A lexicon for endoscopic adverse events: report of an ASGE workshop.
        Gastrointest Endosc. 2010; 71: 446-454
        • Kanda Y.
        Investigation of the freely available easy-to-use software “EZR” for medical statistics.
        Bone Marrow Transplant. 2013; 48: 452-458
        • Tomoda T.
        • Kato H.
        • Kawamoto H.
        • et al.
        Usefulness of a newly designed plastic stent for endoscopic re-intervention in patients with malignant hilar biliary obstruction.
        Endoscopy. 2017; 49: 1087-1091
        • Okuno M.
        • Mukai T.
        • Iwashita T.
        • et al.
        Evaluation of endoscopic reintervention for self-expandable metallic stent obstruction after stent-in-stent placement for malignant hilar biliary obstruction.
        J Hepatobiliary Pancreat Sci. 2019; 26: 211-218
        • Inoue T.
        • Naitoh I.
        • Okumura F.
        • et al.
        Reintervention for stent occlusion after bilateral self-expandable metallic stent placement for malignant hilar biliary obstruction.
        Dig Endosc. 2016; 28: 731-737
        • Figueroa-Barojas P.
        • Bakhru M.R.
        • Habib N.A.
        • et al.
        Safety and efficacy of radiofrequency ablation in the management of unresectable bile duct and pancreatic cancer: a novel palliation technique.
        J Oncol. 2013; (;2013:910897.)
        • Wang F.
        • Li Q.
        • Zhang X.
        • et al.
        Endoscopic radiofrequency ablation for malignant biliary strictures.
        Exp Ther Med. 2016; 11: 2484-2488
        • Cho J.H.
        • Jeong S.
        • Kim E.J.
        • et al.
        Long-term results of temperature-controlled endobiliary radiofrequency ablation in a normal swine model.
        Gastrointest Endosc. 2018; 87: 1147-1150
        • Park J.S.
        • Jeong S.
        • Kobayashi M.
        • et al.
        Safety, efficacy, and removability of a fully covered multi-hole metal stent in a swine model of hilar biliary stricture: a feasibility study.
        Endosc Int Open. 2019; 7: E498-E503
        • Yoon W.J.
        • Kim Y.T.
        • Daglilar E.S.
        • et al.
        Evaluation of bipolar radiofrequency ablation for occluded self-expandable metal stents in the bile duct: in vivo and in vitro study.
        Endoscopy. 2015; 47: 1167-1170
        • Duan X.H.
        • Wang Y.L.
        • Han X.W.
        • et al.
        Intraductal radiofrequency ablation followed by locoregional tumor treatments for treating occluded biliary stents in non-resectable malignant biliary obstruction: a single-institution experience.
        PLoS One. 2015; 10e0134857
        • Kadayifci A.
        • Atar M.
        • Forcione D.G.
        • et al.
        Radiofrequency ablation for the management of occluded biliary metal stents.
        Endoscopy. 2016; 48: 1096-1101
        • Xia N.
        • Gong J.
        • Lu J.
        • et al.
        Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: a preliminary result.
        World J Gastroenterol. 2017; 23: 1851-1856
        • Inoue T.
        • Ito K.
        • Yoneda M.
        Novel balloon catheter-based endobiliary radiofrequency ablation system: ex-vivo experimental study.
        Dig Endosc. 2020; 32: 974-978
        • Inoue T.
        • Kutsumi H.
        • Ibusuki M.
        • et al.
        Feasibility of balloon-based endobiliary radiofrequency ablation under cholangioscopy guidance in a swine model.
        Sci Rep. 2021; 11: 14254