Endoscopic Radiofrequency Ablation Combined with Metal Stent Placement for Malignant Biliary Stricture

Summary

This protocol details endoscopic RFA combined with metal stent placement for unresectable malignant biliary strictures, aiming to standardize the minimally invasive procedure and guide its clinical application to improve biliary patency and patient outcomes.

Abstract

Malignant biliary strictures (MBS) are a challenging clinical issue with limited therapeutic options for unresectable cases. This protocol establishes a standardized minimally invasive approach of endoscopically-guided biliary radiofrequency ablation (RFA) combined with self-expandable metal stent (SEMS) placement via endoscopic retrograde cholangiopancreatography (ERCP) for MBS. The core workflow includes preoperative preparation, endoscopic exploration and cholangiography, direct cholangioscopic assessment, targeted RFA of the stenotic segment, SEMS deployment, and postoperative management and follow-up. Key procedural parameters are defined: bipolar RFA at 8 W for 90–120 s, and placement of a covered SEMS (CSEMS) with 1 cm extension beyond the stenosis margins. Clinical application in a representative case achieved rapid resolution of jaundice (70% reduction in total bilirubin at 5 days post-procedure) and technical success with unobstructed biliary patency at 1 month. The procedure has a favorable safety profile, with no major acute complications observed in the case. This standardized protocol provides a reproducible method for clinical practitioners, and the combined technique offers a valuable palliative option for unresectable MBS by prolonging stent patency and alleviating biliary obstruction symptoms. Further multicenter trials are needed to validate its long-term efficacy in larger patient cohorts.

Introduction

Malignant biliary strictures (MBS) are caused by primary or secondary tumors and are characterized by insidious onset and rapid progression, resulting in most patients being diagnosed at an advanced, unresectable stage¹. Surgical resection remains the only curative treatment option but is feasible in only 10%–40% of patients with cholangiocarcinoma, with a median survival of less than 24 months². Systemic therapies, including chemotherapy, radiotherapy, and immunotherapy, frequently demonstrate limited efficacy because of the complex tumor microenvironment and high genetic heterogeneity of biliopancreatic malignanc....

Protocol

All procedures were performed in accordance with the 1964 Declaration of Helsinki and its later amendments. Written informed consent was obtained from the patient before all interventions. The reagents and the equipment used are listed in the Table of Materials.

1. Preoperative preparation

1. Patient position: Position the patient in the left lateral or prone decubitus position, with the head tilted to the right to facilitate endoscopic insertion.
2. Anesthesia method: Administer deep intravenous sedation with endotracheal intubation general anesthesia to ensure analgesia, amnesia, and muscl....

Results

This protocol integrates ERCP, cholangioscopic direct assessment, targeted RFA, and CSEMS placement into a complete diagnosis-ablation-drainage workflow, establishing a standardized minimally invasive treatment model for unresectable MBS.

The technique achieved technical success and favorable short-term clinical outcomes in the representative case, with clear procedural and clinical metrics that validate the reproducibility and efficacy of the method. Below is a detailed analysis of the proced.......

Discussion

This protocol details a standardized ERCP-guided RFA combined with CSEMS placement technique for unresectable MBS, with a focus on procedural reproducibility, key technical steps, and clinical safety. The representative case validates the technical feasibility and short-term efficacy of the method, and the following discussion addresses critical procedural steps, troubleshooting strategies, technical limitations, and the clinical significance of the technique, aligned with the methods-focused requirements of a JoVE publi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Biliary radiofrequency ablation catheter:Habib EndoHPB bipolar electrode	Boston Scientific	M00500070	The working area is composed of two stainless steel electrodes with a length of 8mm and an interval of 8mm, with a total length of 180cm and a diameter of 8fr, suitable for 0.035 guidewire.
Biliary self-expanding metal stents	Micro-Tech Medical (Nanjing)	BDS-Z-6/80-3/1800-A	Cemented stent, diameter 6mm,Length: 80 cm
Disposable Sphincterotome	Olympus	KD-V411M-0725
duodenoscope	Olympus	TJF-260V
guidewire	Olympus	G-260-2545S/G-260-3545S	0.035/0.025 inch hydrophilic guidewire
radio frequency generator	ERBE Elektromedizin GmbH	VIO 200
Single-use Video Pancreaticobiliary Scope:eyeMax	Micro-Tech Medical (Nanjing) Co., Ltd	CDS22001