Background: Malignant hilar biliary obstruction (MHBO) can be treated by stent deployment under endoscopic retrograde cholangiopancreatography. In case of unresectable MHBO, uncovered self-expandable metal stent (UCSEMS) deployment might be recommended. However, endoscopic revision is challenging. To overcome this issue, we previously described a novel revision technique called the "molting technique," but its technical feasibility is still unclear.
Objective: The present study aimed to evaluate the technical feasibility of the molting technique in a prospective setting.
Design: A single-center prospective study.
Methods: Technical success was defined as successful endoscopic revision using the molting technique. If endoscopic revision using the molting technique in the hepatic bile duct failed on either side, the technique was considered a technical failure.
Results: A total of 20 patients were prospectively enrolled in this study. The technical success rate was 90% (18/20). The mean procedure time was 20.6 ± 8.5 min, and clinical success was obtained in 94.4% of patients (17/18). The mean duration of stent patency after endoscopic revision was 118.2 days. Finally, adverse events were observed in three patients (pancreatitis, n = 2, cholangitis, n = 1), all of whom were successfully treated conservatively.
Conclusion: In conclusion, the molting technique might be helpful as an option for endoscopic revision for multiple UCSEMS deployments for selected patients.
Trail registration: University Hospital Medical Information Network 000044572.
Keywords: ERCP; dilation; hilar biliary obstruction; malignant biliary obstruction; revision.
Novel technique to treat stent blocks Why was the study done? When cancer blocks the bile ducts near the liver (malignant hilar biliary obstruction), doctors often place a stent (a small tube) to keep the bile flowing. If surgery is not possible, uncovered metal stents (UCSEMS) are commonly used because they stay open longer than plastic ones. However, if the stent becomes blocked again, replacing or revising it with another endoscopic procedure can be difficult. We previously developed a new method called the “molting technique” to help with this, but we weren’t sure how well it would work. This study aimed to find out how safe and effective the molting technique is in real patients. What did the researchers do? We looked at whether the molting technique could successfully fix a blocked stent. If the technique failed on either side of the bile ducts in the liver, it was considered a failure. We also checked how well patients improved after the procedure and whether they had any complications. What did the researchers find? We included 20 patients who needed their stents fixed because cancer had grown into them. The molting technique was successful in 18 out of 20 patients (90%). On average, the procedure took about 21 minutes. Of the 18 successful cases, 17 patients (94.4%) showed clinical improvement. After the revision, the new stents remained open for an average of 118 days. Three patients had complications (2 had pancreatitis and 1 had cholangitis), but all recovered with medication. What do the findings mean? The molting technique may be a useful option for fixing blocked metal stents in the bile ducts. However, more research “especially larger, controlled studies” is needed to confirm these findings.
© The Author(s), 2025.