Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety

Role of Endoscopic Ultrasound in the Management of Pancreatic Cancer

Pancreatic cancer is one of the common causes of cancer-associated mortality with a dismal overall prognosis which has remained virtually unchanged over decades. In the present era, the management of patients with pancreatic cancer involves a multi-disciplinary team of radiologists, gastroenterologists, surgical oncologists, medical oncologists, radiation oncologists and other specialists. The advancement of interventional endoscopy has made a significant impact in the management of pancreatic cancers. Since the inception of endoscopic ultrasound, it has evolved over the last few decades in the management of pancreatic malignancies and its role in staging and tissue acquisition is well established. There is an emerging role of endoscopic ultrasound in the treatment and palliation of unresectable pancreatic cancer. The aim of this article is to review the role of endoscopic ultrasound in diagnostic and therapeutic interventions in the current era.

Ablation Therapy of the Biliary Tree: Status and Comprehensive Review

Malignant biliary obstruction is typically referred to endoscopists for palliation. A curative resection is indeed rarely an option in this condition. Photodynamic therapy and radiofrequency ablation are 2 modalities that can be offered in those patients. Many studies have demonstrated improved stent patency and survival after ablation. Photodynamic therapy is unfortunately very expensive and is associated with photosensitivity; however, it transmits to the entire biliary tree. Radiofrequency ablation is more affordable and easier to apply but requires contact with the tumor to be efficient. This review explores both modalities in terms of their safety and efficacy for bile duct cancer palliation.

Advancements in Microwave Ablation Techniques for Managing Pancreatic Lesions

Thermal ablation, including microwave ablation, has become increasingly important in the management of many solid tumors, including primary and metastatic tumors of the liver, kidney, and lung. However, its adoption to treat pancreatic lesions has been slowed due to concerns about potential adverse events. The success of radiofrequency ablation (RFA) in inoperable pancreatic cancers paved the way for its use in pancreatic neuroendocrine tumors and pancreatic cystic neoplasms (PCLs). In the last decade, other thermal ablation techniques, like microwave ablation, have emerged as alternatives to RFA. Microwaves, with frequencies ranging from 900 to 2450 MHz, generate heat by rapidly oscillating water molecules. Microwave ablation's advantage lies in its ability to achieve higher intra-lesion temperatures and uniform heating compared with RFA. Microwave ablation's application in pancreatic cancer and pancreatic neuroendocrine tumors has demonstrated promise with similar technical success to RFA. Yet, concern for peri-procedure complications, as well as a dearth of studies comparing RFA and microwave ablation, emphasize the need for further research. No studies have evaluated microwave ablation in PCLs. We herein review thermal ablation's potential to treat pancreatic lesions.

Long-term Outcomes of Endoscopic Intraductal Radiofrequency Ablation for Ampullary Adenoma with Intraductal Extension after Endoscopic Snare Papillectomy

Background/Aims

There are limitations in treating ampullary adenomas with intraductal extension using conventional endoscopic modalities. Endoscopic intraductal radiofrequency ablation (ID-RFA) may be useful for treating intraductal (common bile duct [CBD] and/or pancreatic duct [PD]) extensions of ampullary adenomas, but long-term data are lacking. We thus evaluated the long-term outcomes of endoscopic ID-RFA for managing ampullary adenomas with intraductal extension.

Methods

Prospectively collected endoscopic ID-RFA database at Asan Medical Center was reviewed to identify consecutive patients with ampullary adenoma who underwent ID-RFA for intraductal extension between January 2018 and August 2021. Technical success, short-term and long-term clinical success, and adverse events were evaluated.

Results

A total of 29 patients (14 CBD, 1 PD, and 14 CBD and PD) were analyzed. All patients had undergone endoscopic snare papillectomy prior to ID-RFA. A median of one session of ID-RFA (range, 1 to 3) for residual or relapsed intraductal extension of ampullary adenoma were successfully performed (technical success=100%). Both biliary and pancreatic stenting were routinely performed after ID-RFA to prevent ductal stricture. After a median follow-up of 776 days (interquartile range, 470 to 984 days), the short-term and long-term clinical success rates were 93% and 76%, respectively. Seven patients experienced procedural adverse events and three patients developed ductal strictures.

Conclusions

Endoscopic ID-RFA showed good long-term outcomes in treating residual or relapsed ampullary adenomas with intraductal extension. Repeated ID-RFA may be considered as an option for managing recurrence. Further studies are needed to standardize the procedure.

Contemporary advances in the endoscopic management of cholangiocarcinoma: a review of accomplished milestones and prospective opportunities

INTRODUCTION

Cholangiocarcinoma, a primary malignancy of epithelial cells of the bile ducts, has been shown to have increasing incidence rates globally. Many of the current advances aim to improve the accuracy of differentiation between benign biliary strictures and cholangiocarcinoma, which include endoscopic techniques, devices, image processing, and the use of genomic sequencing in acquired specimens.

AREAS COVERED

In this review, the authors explore the historical timeline of changes leading to modern management of cholangiocarcinoma, with special emphasis on endoscopic modalities and novel therapeutic interventions. The authors also expand on the strengths and shortcomings of endoscopic diagnostics and techniques in biliary drainage and finally discuss potential areas to focus for future research and development.

EXPERT OPINION

Despite the advances in diagnosis and management of cholangiocarcinoma, there remain multiple tasks that are still awaiting to be completed. Next-generation sequencing in the diagnosis of cholangiocarcinoma needs to be further tested, validated, and easily obtainable. Other innovative diagnostic modalities, such as the use of artificial intelligence in cholangioscopy, may provide an effective complementary modality to existing techniques. A consensus on biliary drainage needs to be defined and account for longevity and patient convenience.

EUS-RFA of the pancreas: where are we and future directions

Surgical resection remains the gold standard for pancreatic cancer, high-risk pancreatic neuroendocrine tumors (PNETs) and pancreatic cystic neoplasms (PCNs). However, a majority of pancreatic cancers are unresectable at the time of diagnosis. In addition, surgical resection of pancreatic lesions can be associated with morbidity and mortality. A less-invasive alternative therapeutic intervention to avoid short term and long-term adverse events is desirable, as is a minimally-invasive palliative therapy for unresectable or recurrent pancreatic cancers. Endoscopic ultrasound guided radiofrequency ablation (EUS-RFA) allows for selective tissue ablation with minimal injury to the surrounding tissue. EUS-RFA of pancreatic tumors has shown high clinical and technical success with acceptable side effects in pancreatic lesions, lymph nodes, and the celiac plexus. This paper will review the pathophysiology, available technology, safety and efficacy, and future directions of EUS-RFA.

Endoscopic Ultrasound-Guided Radiofrequency Ablation as an Future Alternative to Pancreatectomy for Pancreatic Metastases from Renal Cell Carcinoma: A Prospective Study

Simple Summary

Glandular metastases and more precisely pancreatic metastases (PM) from renal cell carcinoma (mRCC) are associated with a long survival. Focal treatment in order to control oligo-metastatic disease and avoid systemic therapy is a standard in RCC. However, pancreatic radiofrequency ablation remains a marginal and under evaluated technic. Standard treatment remains pancreatectomy with hazardous outcomes. We report here the largest series of endoscopic radiofrequency ablation (EUS-RFA) on PM for patient treated at Institut Paoli-Calmettes for a mRCC. Patients with progressive PM was treated under general anesthesia with an ultrasound guided endoscopic radiofrequency ablation procedure then followed by CT-scan. We prospectively included 12 patients, median age was 70.5 years old and median size and number of PM at inclusion was 17 mm and 1 respectively. All 26 procedures performed went as planned and no immediate complications were experienced. After 27.7 months of follow-up, the 6- and 12-month focal control rates were 84% and 73% respectively. Two severe complications occurred after EUS-RFA but were totally resolved after specific treatment. In total, EUS-RFA is feasible and displayed an excellent focal control and should be integrated in the arsenal to treat PM from mRCC in order to spare systemic therapy and/or pancreatic surgery.

Abstract

Background: Pancreatic metastases (PM) from renal cell carcinoma (RCC) are rare, are associated with favorable outcomes and are usually handled by surgery or VEGFR inhibitors, which both have side effects. Endoscopic Ultrasound (EUS)-guided radiofrequency ablation (RFA) is an innovative approach to treat focally deep metastases and could be a relevant technique to control PM from RCC. Methods: This monocentric, prospective study aimed to evaluate the safety and efficacy of EUS-RFA to treat PM. We included patients with confirmed and progressive PM from RCC. PM was ablated under general anesthesia with a linear EUS scope and a EUS-RFA 19-gauge needle electrode placed into the tumor. Results: Twelve patients from Paoli-Calmettes Institute were recruited between May 2017 and December 2019. Median age was 70.5 years (range 61–75), 50% were female, 100% were ECOG 0–1. At inclusion, mean PM size was 17 mm (range 3–35 mm); and all were progressive before EUS-RFA. Seven patients had EUS-RFA as the only treatment for RCC. We performed 26 EUS-RFA procedures and 21 PM was ablated. Median follow up was 27.7 months (range 6.4–57.1). For evaluable PM, the 6- and 12-month focal control rates were 84% and 73% respectively. One patient treated with TKI developed a paraduodenal abscess 2 months after EUS-RFA and another patient with biliary stent developed hepatic abscesses few days after EUS-RFA. No other severe side effects were experienced. Conclusions: in this series, which is the largest ever reported, we showed that EUS-RFA is feasible and yields an excellent local control rate for PM from mRCC. With manageable complications, it could be a valuable alternative to pancreatic surgery in well-selected patients.

Development of Radiofrequency Ablation Generator and Balloon-Based Catheter for Microendoluminal Thin-Layer Ablation Therapy Using the Rat Duodenum as a Model of Low-Impedance Tissue

Radiofrequency ablation (RFA) is a routinely used, safe, and effective method for the tissue destruction. Often, in case of its application in malignant conditions, the extent of tissue destruction is insufficient due to the size of the target lesion, as well as due to the risk of heat-induced damage to the surrounding organs. Nevertheless, there are conditions requiring superficial precise-depth ablation with preservation of deeper layers. These are represented, for example, by mucosal resurfacing in case of Barrett's esophagus or treatment of recurrent mucosal bleeding in case of chronic radiation proctitis. Recently, new indications for intraluminal RFA use emerged, especially in the pancreatobiliary tract. In the case of intraductal use of RFA (e.g., biliary and pancreatic tract), there are currently available rigid and needle tip catheters. An expandable balloon-based RFA catheter suitable for use in such small-diameter tubular organs could be of benefit due to possible increase of contact between the probe and the target tissue; however, to prevent excessive tissue damage, a compatible generator suitable for low-impedance catheter/tissue is essential. This project aimed to develop a radiofrequency ablation generator and bipolar balloon-based catheter optimized for the application in the conditions of low-impedance tissue and (micro)endoluminal environment. Subsequent evaluation of biological effect in vivo was performed using duodenal mucosa in Wistar rat representing conditions of endoluminal radiofrequency ablation of low-impedance tissue. Experiments confirming the safety and feasibility of RFA with our prototype devices were conducted.

Advances in the management of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary malignancy of the bile ducts with three anatomically and molecularly distinct entities: Intrahepatic CCA (iCCA), perihilar CCA (pCCA), and distal CCA. As a result of phenotypic and anatomic differences they differ significantly with respect to management. For each type of CCA there have been significant changes in management over the last several years which will be discussed in this review. Although resection remains the standard of care for all types of CCA, liver transplantation has been established as curative treatment for selected patients with pCCA and is being evaluated for iCCA with early success. With respect to systemic therapy capecitabine is now first line adjuvant therapy for all biliary tract malignancies after curative intent resection. Progress in exploiting the pathologic mutations and molecular abnormalities has also yielded regulatory approval of targeted therapy for CCA in patients with acquired alterations in the fibroblast growth factor receptor. There is also increased consensus in managing malignant biliary obstruction associated with CCA where pre-operative biliary stenting is not beneficial while self-expanding metal stents have been shown to be superior to plastic stents in patients who are not surgical candidates.

Advancements in Endoscopic Biliary Interventions by Gastroenterology

Endoscopic retrograde cholangiopancreatography (ERCP) is an endoscopic technique in which a specialized side-viewing endoscope is guided into the duodenum, allowing for instruments to access the biliary and pancreatic ducts. ERCP was initially developed as a diagnostic tool as computed tomography was in its infancy during that time. ERCP has evolved since its inception in the 1960s to becoming not only a valuable diagnostic resource but now an effective therapeutic intervention in the treatment of various biliary disorders. The most common biliary interventions performed by ERCP include the management of biliary obstructions for benign and malignant indications. Additionally, endoscopic ultrasound (EUS) has been increasingly utilized in diagnosing and intervening on pancreaticobiliary lesion. This article will discuss the various methods currently available for various endoscopic biliary interventions and future interventional techniques. For the management of biliary strictures, EUS can be utilized with fine need aspiration, while ERCP can be used for the placement of various stents and diagnostic modalities. Another example is radiofrequency ablation, which can be used for the treatment of hilar strictures. Achieving bile duct access can be challenging in patients with complicated clinical scenarios; other techniques that can be used for bile duct access include EUS-guided rendezvous approach, transluminal approach, Choleodochoduodenostomy, and hepatogastrostomy, along with gaining access in complicated anatomy such as in patients with Rou-en-Y anatomy. Another useful endoscopic tool is nonsurgical drainage of the gallbladder, which can be a suitable option when patients are not optimal surgical candidates. There has also been an increase in outpatient utilization of ERCP, which was previously seen as a predominantly inpatient procedure in the past. Possible future evolutions of biliary interventions include robotic manipulation of a duodenoscope and direct infusion of chemotherapeutic or immunomodulatory agents into the pancreaticobiliary tree. These advancements will depend on parallel advancements in other imaging and laboratory as well as breakthrough technology or techniques by other disciplines including interventional radiology and minimally invasive surgery.

Personalized Approach to the Role of Endoscopic Ultrasound in the Diagnosis and Management of Pancreaticobiliary Malignancies

Pancreaticobiliary malignancies arise from different areas within the pancreas and biliary tree. Endoscopic ultrasound (EUS) is a well-recognized diagnostic and therapeutic modality in the treatment of pancreaticobiliary diseases, and more specifically, pancreaticobiliary malignancies. Traditionally used for diagnostic purposes, EUS plays a critical role in tissue sampling and cancer staging. The emergence of the new field of interventional EUS has allowed EUS to also play a critical role in therapeutic management. Novel interventional EUS procedures such as EUS-guided gastrojejunostomy (EUS-GE), EUS-guided biliary drainage (EUS-BD), and EUS-guided gallbladder drainage (EUS-GLB) can be utilized to treat complications of pancreaticobiliary malignancies such as gastric outlet obstruction, obstructive jaundice, and cholecystitis. In addition, interventional EUS procedures can be utilized for the palliation of unresectable malignancies both for source control with EUS-radiofrequency ablation (EUS-RFA) and for the treatment of abdominal pain refractory to opioid medications with EUS-guided celiac axis neurolysis. However, patient selection remains a critical component in both diagnostic and therapeutic interventions and must be tailored to individual patient wishes, disease pathology, and overall prognosis.

Role of Intraductal RFA: A Novel Tool in the Palliative Care of Perihilar Cholangiocarcinoma

Background

Patients with irresectable perihilar cholangiocarcinoma (PHC) have a limited prognosis with median survival times still less than 1 year. In addition to the current standard first-line systemic chemotherapy (gemcitabine and a platinum derivate), endoscopic treatment aims to ensure adequate drainage of the biliary system by placing biliary plastic or metal stents. Local ablative procedures like intraluminal biliary brachytherapy (ILBT) or photodynamic therapy (PDT) are used to improve local tumor control and to optimize the stent patency.

Summary

Intraductal radiofrequency ablation (RFA) is another promising tool in the therapeutic armamentarium for the endoscopic management and tumor ablation of extrahepatic cholangiocarcinoma (eCCA). By applying thermal energy to the tissue through high-frequency alternating current, RFA induces coagulative necrosis and causes local destruction of the tumor. It is established as a first line percutaneous treatment of solid liver tumors, and since 2011 an endoscopic catheter is available that allows intraductal RFA in the biliary or pancreatic ducts. While the first pilot studies primarily evaluated this new method in patients with distal eCCA, there is now evidence accumulating also for PHC. Two retrospective and two prospective studies demonstrated a significantly improved overall survival and a longer stent patency with intraductal RFA, which overall had a favorable safety profile and was not associated with a significant increase in adverse events. However, prospective studies comparing the efficacy and safety of intraductal RFA, PDT, and/or ILBT are lacking.

Key Messages

Recent studies suggest that intraductal RFA is an effective and well-tolerated additional treatment option with regard to stent patency but also overall survival. Since RFA has fewer systemic side effects and requires less logistical effort when compared to ILBT and PDT, intraductal RFA should be considered as another safe and feasible adjuvant method for the palliative care of patients with advanced PHC. Since comparative studies are lacking, the choice of the local ablative method remains in each case an individual decision.

Endoscopic radiofrequency ablation plus a novel oral 5-fluorouracil compound versus radiofrequency ablation alone for unresectable extrahepatic cholangiocarcinoma

BACKGROUND AND AIMS

Endoscopic radiofrequency ablation (RFA) is a new ablative treatment for unresectable extrahepatic cholangiocarcinoma (EHCC). A novel 5-fluorouracil compound, S-1 (Taiho Pharmaceutical Co, Ltd, Tokushima Plant. Japan), has been widely used as a key drug with first-line or second-line chemotherapy for the treatment of advanced cholangiocarcinoma. The aim of this study was to evaluate the clinical efficacy and safety of endoscopic RFA combined with S-1 for the treatment of unresectable locally advanced EHCC.

METHODS

Patients with unresectable EHCC were prospectively randomized to 1 of 2 groups: the RFA + S-1 group and the RFA group. Median overall survival (OS), stent patency time, Karnofsky performance status (KPS) score, and adverse events rate were analyzed.

RESULTS

The median OS was longer in the RFA + S-1 group (n = 37) than that in the RFA group (n = 38) (16.0 months [95% confidence interval, 13.1-19.0] vs 11.0 months [95% confidence interval, 9.7-12.3]; P < .001). Stent patency time was significantly longer in the RFA + S-1 group than that in the RFA group (6.6 ± 1.5 vs 5.6 ± .1 months, P = .014). KPS scores at postoperative month 9 (51.6 ± 17.0 vs 40.4 ± 16.4, P = .012) and month 12 (35.2 ± 18.3 vs 23.9 ± 11.4, P = .014) were all higher in the RFA + S-1 group than those in the RFA group (P < .05). The incidence of ERCP-related adverse events was not significantly different between RFA+S-1 and RFA groups (8.1% vs 10.5%, P > .05).

CONCLUSIONS

For the treatment of locally advanced EHCC, endoscopic RFA combined with S-1 is associated with longer survival and stent patency and improved functional status than RFA alone. (Clinical trial registration number: NCT02592538.).

Efficacy and safety of palliative endobiliary radiofrequency ablation using a novel temperature-controlled catheter for malignant biliary stricture: a single-center prospective randomized phase II TRIAL

BACKGROUND

Endobiliary radiofrequency ablation (EB-RFA) has emerged as a palliative treatment for malignant biliary strictures (MBSs); however, concerns about complications related to thermal injury remain. In this study, we evaluated the efficacy and safety of EB-RFA with a novel catheter for MBS.

METHODS

Patients with inoperable cancer causing MBS were randomly assigned to either the radiofrequency ablation (RFA) group or the non-RFA group. The RFA group underwent EB-RFA at the stricture site with a temperature-controlled catheter (ELRA™; STARmed Co., Goyang, Korea) followed by deployment of a self-expanding metal stent (SEMS). For the non-RFA group, only SEMS placement was performed. The duration of stent patency, overall survival (OS), and 30-day complication rate were evaluated. This trial was registered at ClinicalTrials.gov (number NCT02646514).

RESULTS

A total of 48 patients were enrolled (24 in each group). During a median follow-up period of 135.0 days (RFA group) and 119.5 days (non-RFA group), the 90-day stent patency rate, median duration of stent patency, and median OS were not different between the groups (58.3% vs. 45.8% [P = 0.386], 132.0 days vs. 116.0 days [P = 0.440], and 244.0 days vs. 180.0 days [P = 0.281], respectively). In the RFA group, procedure-related complications including thermal injury-related complications, such as bile duct perforation or hemobilia, were not reported. The early complication (< 7 days) rates were not different between the groups (4.2% vs. 12.5%, P = 0.609), and there were no late complications (7-30 days) in both groups.

CONCLUSION

EB-RFA with a temperature-controlled catheter followed by SEMS placement for patients with inoperable MBS can be safe and feasible with acceptable biliary patency.

Photothermal Depletion of Cancer-Associated Fibroblasts Normalizes Tumor Stiffness in Desmoplastic Cholangiocarcinoma

Physical oncology recognizes tissue stiffness mediated by activation of cancer-associated fibroblasts (CAF) and extracellular matrix remodeling as an active modulator of tumorigenesis, treatment resistance, and clinical outcome. Cholangiocarcinoma (CCA) is a highly aggressive and chemoresistant desmoplastic cancer enriched in CAF. CCA's stroma mechanical properties are considered responsible for its chemoresistant character. To normalize tumor mechanics, we propose a physical strategy based on remotely light-activated nanohyperthermia to modulate the tumor microenvironment. In this study, we report the use of multifunctional iron oxide nanoflowers decorated with gold nanoparticles (GIONF) as efficient nanoheaters to achieve complete tumor regression following three sessions of mild hyperthermia. The preferential uptake of GIONF by CAF allowed targeting this cell population, which resulted in a significant early reduction of tumor stiffness followed by tumor regression. In conclusion, our study highlights a spatially and temporally controlled physical strategy, GIONF-mediated photothermal therapy to deplete CAF and normalize the tumor mechanics that may apply to desmoplastic cancer and CCA treatment.

Endoluminal radiofrequency ablation with SpyGlass™ in the management of cholangiocarcinoma

Most extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis and even in case of a resectable cancer, surgery is not an option for the elderly or patients with comorbidities (1). Current treatment alternatives in these scenarios are very limited. Biliary stenting with self-expanding metal stents (SEMS) is the mainstay palliative treatment for biliary obstruction (2). However, emerging experience with endoscopic RF ablation (RFA) in this setting has been reported in the literature.

Development of a biliary multi-hole self-expandable metallic stent for bile tract diseases: A case report

BACKGROUND

Uncovered stents used for malignant obstructions in the biliary tree, especially in the hilar area, are prone to obstruction by tumor ingrowths. In comparison, however, covered stents may block bile duct branches and are at risk of migration. We have developed a multi-hole self-expandable metallic stent (MHSEMS), with a hole in each cell, to prevent the obstruction of bile duct branches. In addition, the holes may prevent migration due to small ingrowths by reducing the tension of the membrane.

CASE SUMMARY

MHSEMS were placed in five patients with a malignant obstruction and one with post-endoscopic sphincterotomy bleeding. Each MHSEMS was successfully deployed in all cases. Patients showed no complications. Two cases were reviewed. Case 1: A 74-year-old male presented with jaundice and was diagnosed with a sigmoid colon cancer and giant liver metastases in the right liver lobe. A MHSEMS was placed in the left bile duct. The jaundice improved and peroral cholangioscopy was performed. Case 2: A 90-year-old female was admitted to hospital for jaundice and diagnosed with cholangiocarcinoma. A MHSEMS was placed in the left bile duct but after 8 months the stent became obstructed by tumor ingrowth. We treated the patient by ablation therapy. A silicone cover separated the internal bile duct from the surrounding tissue, protecting the latter from thermal injury during treatment by endobiliary ablation of the re-obstruction.

CONCLUSION

A MHSEMS is a new choice of stent for biliary tract diseases.

Radiofrequency and malignant biliary strictures: An update

Malignant biliary strictures are usually linked to different types of tumors, mainly cholangiocarcinoma, pancreatic and hepatocellular carcinomas. Palliative measures are usually adopted in patients with nonresectable or borderline resectable biliary disease. Stent placement is a well-known and established treatment in patients with unresectable malignancy. Intraductal radiofrequency ablation (RFA) represents a procedure that involves the use of a biliary catheter device, via an endoscopic approach. Indications for biliary RFA described in literature are: Palliative treatment of malignant biliary strictures, avoiding stent occlusion, ablating ingrowth of blocked metal stents, prolonging stent patency, ablating residual adenomatous tissue after endoscopic ampullectomy. In this mini-review we addressed focus on technical success defined as deployment of the RF catheter, virtually succeeded in all patients included in the studies. About efficacy, three main outcome measures have been contemplated: Biliary decompression and stent patency, survival. Existing studies suggest a beneficial effect on survival and stent patency with RFA, but current impression is limited because most of studies have been performed using a retrospective design, on diminutive and dissimilar cohorts of patients.

Endobiliary Radiofrequency Ablation in the Percutaneous Management of Refractory Benign Bilioenteric Anastomosis Strictures

OBJECTIVE

The purpose of this study is to evaluate the safety and efficacy of endobiliary radiofrequency ablation (RFA) in the percutaneous management of benign bilioenteric anastomosis strictures that are refractory to balloon dilatation and long-term drainage.

MATERIALS AND METHODS

Twenty-one patients (11 men) with a mean age of 47.9 years (range, 26-73 years) underwent percutaneous balloon dilatation and long-term drainage for benign bilioenteric anastomosis strictures. Endobiliary RFA was performed in six patients (four men; mean age, 53.1 years; range, 43-63 years) whose strictures did not respond to balloon dilatation and long-term drainage.

RESULTS

Presenting symptoms were jaundice (n = 21), pain (n = 19), pruritus (n = 17), and cholangitis (n = 15). The symptoms appeared 1384 days (range, 4-7592 days) after surgery. The technical success rate was 100%. The overall clinical success rate was 95.2% (20/21) with a mean follow-up of 67.3 months (range, 9-148 months) after catheter removal. In 15 patients, associated biliary stones were removed. Two patients with recurrent strictures were successfully retreated. Endobiliary RFA was successful and catheter removal could be achieved in all six patients (100%) whose disease did not respond to multiple balloon dilatation sessions and long-term drainage. The mean symptom-free period after endobiliary RFA and catheter removal was 430 days (range, 270-575 days). One patient with refractory disease (4.7%), for whom endobiliary RFA was not performed, underwent surgery. There were no major complications.

CONCLUSION

Endobiliary ablation may be used safely and effectively in the percutaneous management of benign bilioenteric anastomosis strictures that are refractory to balloon dilatation and long-term drainage, with promising results.

Efficacy and safety of endobiliary radiofrequency ablation for the eradication of residual neoplasia after endoscopic papillectomy: a multicenter prospective study

BACKGROUND AND AIMS

Endobiliary dysplasia may persist after endoscopic papillectomy. Intraductal radiofrequency ablation (ID-RFA) is a potential alternative to complementary surgery. The aim of this study was to evaluate the efficacy and safety of ID-RFA for the treatment of adenomatous intraductal residue after endoscopic papillectomy.

METHODS

A prospective open-label multicenter study included patients with histologically proven endobiliary adenoma remnant (ductal extent <20 mm) after endoscopic papillectomy for ampullary tumor. RFA (effect 8, power 10 W, 30 seconds) was performed during ERCP. Biliary ± pancreatic stent was placed at the end of the procedure. Endpoints were (1) the rate of residual neoplasia (ie, low-grade dysplasia [LGD], high-grade dysplasia [HGD], or invasive carcinoma) at 6 and 12 months, (2) rate of surgery, and (3) adverse events.

RESULTS

Twenty patients (67 ± 11 years of age, 12 men) were included. The endobiliary adenoma was in LGD in 15 patients and HGD in 5 patients. All underwent 1 successful ID-RFA session with biliary stent placement and recovered uneventfully. Five (25%) received a pancreatic stent. The rates of residual neoplasia were 15% and 30% at 6 and 12 months, respectively. Only 2 patients (10%) were referred for surgery. Eight patients (40%) experienced at least 1 adverse event between ID-RFA and 12 months of follow-up. No major adverse event occurred. HGD at inclusion was associated with higher dysplasia recurrence at 12 months (P = .01).

CONCLUSIONS

ID-RFA of residual endobiliary dysplasia after endoscopic papillectomy can be offered as an alternative to surgery, with a 70% chance of dysplasia eradication at 12 months after a single session and a good safety profile. Patient follow-up remains warranted after ID-RFA. (Clinical trial registration number: NCT02825524.).

PHOTOSTENT-02: porfimer sodium photodynamic therapy plus stenting versus stenting alone in patients with locally advanced or metastatic biliary tract cancer

Background

Endobiliary stenting is standard practice for palliation of obstructive jaundice due to biliary tract cancer (BTC). Photodynamic therapy (PDT) may also improve biliary drainage and previous small studies suggested survival benefit.

Aims

To assess the difference in outcome between patients with BTC undergoing palliative stenting plus PDT versus stenting alone.

Methods

92 patients with confirmed locally advanced or metastatic BTC, ECOG performance status 0-3 and adequate biliary drainage were randomised (46 per group) to receive porfimer sodium PDT plus stenting or stenting alone. The primary end point was overall survival (OS). Toxicity and progression-free survival (PFS) were secondary end points. Treatment arms were well balanced for baseline factors and prior therapy.

Results

No significant differences in grade 3-4 toxicities and no grade 3-4 adverse events due to PDT were observed. Thirteen (28%) PDT patients and 24 (52%) stent alone patients received subsequent palliative chemotherapy. After a median follow-up of 8.4 months, OS and PFS were worse in patients receiving PDT compared with stent alone group (OS median 6.2 vs 9.8 months (HR 1.56, 95% CI 1.00 to 2.43, p=0.048) and PFS median 3.4 vs 4.3 months (HR 1.43, 95% CI: 0.93 to 2.18, p=0.10), respectively).

Conclusion

In patients with locally advanced or metastatic BTC, PDT was associated with worse outcome than stenting alone, explained only in part by the differences in chemotherapy treatments. We conclude that optimal stenting remains the treatment of choice for malignant biliary obstruction and the use of PDT for this indication cannot be recommended outside of clinical trials.

Trial registration number

ISRCTN 87712758; EudraCT 2005-001173-96; UKCRN ID: 1461.

Endoscopic management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare but clinically important cholestatic liver disease. Histopathologically and cholangiographically, PSC is characterized by intra- and/or extra-hepatic bile duct inflammation and fibro-obliteration, which ultimately leads to biliary cirrhosis and related sequelae, including development of hepatobiliary and colorectal carcinomata. PSC can be diagnosed at essentially any age and carries a median survival of 15-20 years, regardless of age at diagnosis, and is a foremost risk factor for cholangiocarcinoma. Given the chronic and progressive nature of PSC, its inherent association with both neoplastic and non-neoplastic biliary tract complications, and the lack of effective pharmacotherapies, alimentary and biliary tract endoscopy plays a major role in the care of patients with PSC. Areas covered: Here, we provide a narrative review on endoscopic management of PSC, including established and evolving applications to the diagnosis and treatment of both its benign and malignant complications. Expert commentary: Due to the rarity of PSC and the considerable patient-years required to rigorously study major endpoints, there remains a paucity of high-quality evidence regarding its management. As the advanced endoscopic repertoire expands, so has the interest in developing best practices in PSC, which we discuss herein.

Novel temperature-controlled RFA probe for treatment of blocked metal biliary stents in patients with pancreaticobiliary cancers: initial experience

BACKGROUND AND STUDY AIMS

 Radiofrequency ablation (RFA) is used to treat blocked biliary stents in patients with pancreaticobiliary (PB) tumors with varying results. We report our experience with a novel temperature-controlled probe for treatment of blocked metal stents.

PATIENTS AND METHODS

 Patients with histologically proven PB cancers and a blocked biliary stents were treated using ELRATM electrode (Taewoong Medical) under fluoroscopic guidance. Demographics, clinical outcome, stricture diameter improvements, complications and mortality at 30 days were prospectively recorded.

RESULTS

 Nine procedures were performed on seven patients (4 male, 3 female); mean age 65.33 (range 56 - 82 years). Mean stricture diameter prior to RFA was 1.13 mm (SD ± 0.54) and 4.42 mm (SD ± 1.54) following RFA ( P  < 0.0001). Five of seven patients (71 %) required additional stents to ensure optimal drainage. There were no procedure-related complications. Mean follow-up was 193.55 days (range 31 - 540) and three of nine patients (33 %) died due to terminal cancer.

CONCLUSION

These are the first reported data on use of a temperature-controlled RFA catheter in humans to treat blocked metal biliary stents. The device is safe but further randomized trials are required to establish the efficacy and survival benefits of this probe.

Long-term results of temperature-controlled endobiliary radiofrequency ablation in a normal swine model

BACKGROUND AND AIMS

Endobiliary radiofrequency ablation (EB-RFA) is a new adjunctive method for biliary drainage restoration. However, a concern remains about long-term adverse events of this procedure, such as biliary stricture, perforation, and hemorrhage. Therefore, we aimed to assess the long-term effects of in vivo EB-RFA in a swine model.

METHODS

Six mini-pigs were divided into 2 groups: 10-W/33-mm EB-RFA and 7-W/18-mm EB-RFA. Endoscopic retrograde cholangiography-guided temperature controlled EB-RFA (80°C, 7-10 W, 120 seconds) was performed. After 28 days all mini-pigs underwent follow-up ERC and were killed to assess the long-term effects of EB-RFA.

RESULTS

All mini-pigs developed biliary stricture (median length, 10.5 mm; range, 6-15) with jaundice (total bilirubin, 5.84 mg/dL; range, 4.3-9.2) and purulent bile at 1 month after EB-RFA. A significant difference was found in the length of stricture on cholangiogram between the 10 W/33-mm and 7 W/18-mm EB-RFA groups (median, 14 vs 6 mm; P = .034); however, no differences were found in the width of the stricture and laboratory findings. Histologic examination revealed marked thickening of bile duct with severe damage of whole layers replaced with reactive myofibroblastic proliferation, dense collagen laydown, chronic and acute inflammation, and fat necrosis. However, long-term adverse events, such as perforation or hemorrhage, were not found.

CONCLUSIONS

As a long-term result of EB-RFA, segmental biliary stricture with cholangitis develops in proportion to the power/length of the RFA electrode. Therefore, biliary stents should be placed to maintain biliary drainage after EB-RFA.

Therapy of Pancreatic Neuroendocrine Tumors: Fine Needle Intervention including Ethanol and Radiofrequency Ablation

Pancreatic neuroendocrine tumors (PNETs) are increasingly being detected, though usually as incidental findings. Majority of the PNETs are non-functional and surgical resection is the standard of care for most of them. However, in patients with small PNETs localized within the pancreas, who are unfit or unwilling for surgery, alternate methods of treatment are needed. Direct methods of ablation of PNETs, using either ethanol injection or radiofrequency ablation (RFA), are emerging as effective methods. The limited literature available as case reports or case series on endoscopic ultrasound (EUS)-guided local ablation using either ethanol or RFA has demonstrated safety and efficacy along with short- to medium-term sustained relief. Long-term benefits with these local ablative therapies are awaited. Comparative studies are needed to show which of these two competing technologies is superior. Finally, comparative trials of EUS-guided ablation with surgical resection in terms of efficacy and safety will ensure their place in the management algorithm.

Endoscopic ultrasonography-guided tumor ablation

Real-time guidance of needle advancement has transformed endoscopic ultrasound (EUS) from a diagnostic to an interventional procedure. EUS-guided fine-needle puncture has application in various interventional procedures (drainage of pseudocyst, biliary intervention, and injection of drugs). Celiac plexus or ganglion neurolysis for pain control is the major current EUS-guided fine-needle injection procedure. Feasibility and safety to accurately position needle devices and/or inject under real-time EUS imaging with precise delivery of interventional agent have expanded the use of EUS to ablate tumors. These include radiofrequency ablation, or delivery of fiducial markers, potential antitumor agents, or radioactive seeds, in the cancer mass. Minimally invasive EUS-guided antitumor therapy is primarily used for pancreatic cancer because of better anatomic access (vs other imaging modality) and the dismal prognosis (despite improvements in surgery and chemoradiation). Also, the response to parenteral chemotherapy in pancreatic cancer is poor because of suboptimal drug delivery resulting from hypovascularity and abundant desmoplasia. Other targets for EUS-guided tumor ablation are pancreatic neuroendocrine tumor and pancreatic cyst lesion, which are less aggressive and curable by resection. However, patients non-eligible for surgery may benefit from local EUS-guided ablation.

Biliary strictures: endoscopic assessment and management

The diagnosis of biliary strictures can be challenging. Endoscopy has an established role in the diagnosis and therapy of biliary strictures. However, the diagnostic yield from conventional endoscopic retrograde cholangiopancreatography tissue sampling is modest. Improvements in existing technologies as well as the implementation of novel technologies and techniques have the potential to improve the diagnostic performance of endoscopy and expand its therapeutic role. Recent studies have enabled greater clarity about the role of preoperative biliary drainage and the choice of stents in this setting as well as the utility of metal stents in benign and malignant disease.

Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result

AIM

To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction.

METHODS

We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter.

RESULTS

Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients’ stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d.

CONCLUSION

This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach.