In-stent radiofrequency ablation with uncovered metal stent placement for tumor ingrowth/overgrowth causing self-expandable metal stent occlusion in distal malignant biliary obstruction: multicenter propensity score–matched study

Post written by Namyoung Park, MD, from the Department of Gastroenterology, Kyung Hee University Hospital at Gangdong, Woo Hyun Paik, MD, PhD, from the Department of Internal Medicine and Liver Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, and Jae Hee Cho, MD, PhD, from the Department of Internal Medicine, Institute of Gastroenterology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.


Although both plastic stents and self-expandable metal stents (SEMSs) are frequently used to relieve malignant biliary obstruction (MBO), many studies have shown that the use of SEMSs is associated with better stent patency and a lower rate of adverse events.

However, tumors continue to grow after biliary stenting, leading to stent re-obstruction. In addition, as new cancer treatments show improved survival outcomes, the issue of stent re-obstruction has become more important. Therefore, local methods to prevent these issues are needed.


Several studies have demonstrated the safety and effectiveness of endobiliary radiofrequency ablation (RFA). We considered that this locoregional therapy could improve the time to recurrent biliary obstruction (TRBO) and investigated the efficacy and safety of in-stent RFA (IS-RFA).

To analyze the exact effect of IS-RFA, we enrolled patients who received uncovered SEMSs to treat the tumor ingrowth or overgrowth. The only difference between the 2 groups was whether RFA was performed.

In total, 48 patients with recurrent biliary obstruction because of tumor ingrowth or overgrowth after SEMS placement were enrolled in 3 tertiary hospitals. To alleviate the imbalance of the RFA and control groups, propensity score matching was performed.

The median TRBO was significantly longer in the RFA group (117 days vs 82.5 days; P = .029). The difference in overall survival between groups was insignificant (170 days vs 72 days; P = .902). No significant adverse events were reported after the second SEMS placement in either group. The RFA session was interrupted in 5 of 14 patients. In-stent contact caused all RFA interruption cases, but repeating RFA in the same session in most patients could overcome the interruption.

In the Cox regression analysis, IS-RFA was significantly associated with improved TRBO in both the univariable (hazard ratio [HR], 0.17; 95% confidence interval [CI], .03-.96; P = .045) and multivariable (HR, 0.11; 95% CI, .02-.74; P = .024) analyses.

In conclusion, we demonstrated that IS-RFA with an uncovered SEMS may reduce the recurrence of biliary obstruction when used to treat occluded SEMSs in distal MBO caused by pancreatobiliary cancer. Sufficient ablative energy could be delivered in most patients. The rate of postprocedural adverse events did not differ between the RFA and control groups, and no serious adverse events were reported.

As treatment for occluded SEMSs in pancreatobiliary cancer, IS-RFA with uncovered SEMSs is safe and feasible and may improve TRBO. Well-designed larger prospective studies are required to evaluate the efficacy of IS-RFA.


Graphical Abstract

Read the full article online.

The information presented in Endoscopedia reflects the opinions of the authors and does not represent the position of the American Society for Gastrointestinal Endoscopy (ASGE). ASGE expressly disclaims any warranties or guarantees, expressed or implied, and is not liable for damages of any kind in connection with the material, information, or procedures set forth.

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