Impact of Radiofrequency Ablation on Malignant Biliary Strictures: Results of a Collaborative Registry

Intraductal ablation therapy for malignant biliary obstruction

BACKGROUND

Malignant biliary obstruction is usually attributed to the enlargement of tumors within or adjacent to the biliary tract, leading to blockage or compression of the bile ducts. Common causes include pancreatic head cancer, bile duct cancer, gallbladder cancer, liver cancer, and metastatic diseases. Most cases have an insidious onset, lack effective early screening methods, and 70% of patients cannot undergo surgical resection, with a 5-year survival rate of about 30%. Therefore, relieving biliary tree obstruction is crucial. Biliary stents often mitigate the obstruction but can be hindered by tumor progression, endothelial hyperplasia, and bile sludge. As a result, new treatment approaches are constantly being explored to improve outcomes for patients with malignant biliary obstruction.

CURRENT SITUATION

One promising technique that has emerged in recent years is radiofrequency ablation (RFA). This innovative method utilizes high-frequency radio waves to generate heat and selectively target tumor cells through localized heating while preserving surrounding healthy tissue. RFA aims to slow tumor growth and enhance biliary stent durability. Studies on endoscopic RFA for malignant biliary obstruction are encouraging. Integrating it with palliative care may better manage symptoms and extend patient quality of life.

CONCLUSION

In conclusion, while malignant biliary obstruction remains a complex medical challenge with limited treatment options available for some patients, ongoing research into innovative techniques like radiofrequency ablation offers hope for better outcomes in the future. It is crucial for healthcare professionals to stay informed about these advancements and continue exploring new ways to enhance patient care in this difficult clinical scenario.

Endoluminal radiofrequency ablation with stenting versus stenting alone in patients with malignant biliary obstruction: a meta-analysis of randomized trials

BACKGROUND

Endoluminal radiofrequency ablation (RFA) is a palliative treatment for patients suffering from malignant biliary obstruction (MBO). We aimed to conduct a meta-analysis to evaluate the impact of RFA on stent patency, patient survival, and adverse events.

METHODS

Major databases were searched through December 2023 for patients who had undergone stenting with or without RFA for extrahepatic MBO. A random-effects model was used for analysis, with results expressed as relative risk ratios (RRs) with 95%CIs.

RESULTS

Nine RCTs involving 750 subjects with MBO (374 RFA plus stent vs. 376 stent only) were included. Meta-analysis revealed similar risks of stent patency at 3 months (RR 1.01, 95%CI 0.92-1.11; I 2 = 4%) for RFA plus stenting vs. stent only. Meta-analysis showed improved survival at 6 months (RR 0.84, 95%CI 0.73-0.96; I 2 = 21%; P = 0.01) for RFA plus stenting vs. stent only. Subgroup analysis comparing plastic vs. uncovered metal stents showed that stent patency was unaffected at 3 months (RR 1.06, 95%CI 0.91-1.23; I 2 = 17%). Subgroup analysis showed that patients with cholangiocarcinoma experienced an overall survival benefit with RFA plus stenting vs. stenting alone (P < 0.001); however, stent patency remained unaffected (P = 0.08). An increased incidence of cholecystitis was noted with RFA plus stenting vs. stenting alone (5.1% [95%CI 3.1%-7.8%] vs. 0.3% [95%CI 0.01%-1.5%], respectively).

CONCLUSION

Combining endoluminal RFA and stenting may improve overall survival in patients with MBO. RFA did not significantly impact stent patency.

Radiofrequency ablation via catheter and transpapillary access in patients with cholangiocarcinoma (ACTICCA-2 trial) - a multicenter, randomized, controlled, open-label investigator-initiated trial

BACKGROUND

Despite the recent advances in cancer treatment, the therapeutic options for patients with biliary tract cancer are still very limited and the prognosis very poor. More than 50% of newly diagnosed patients with biliary tract cancer are not amenable to curative surgical treatment and thus treated with palliative systemic treatment. Malignant bile duct obstructions in patients with perihilar and/or ductal cholangiocarcinoma (CCA) represents one of the most important challenges in the management of these patients, owning to the risk represented by developing life-threatening cholangitis which, in turn, limits the use of systemic treatment. For this reason, endoscopic stenting and/or bile duct decompression is the mainstay of treatment of these patients. Data on efficacy and safety of adding radiofrequency ablation (RFA) to biliary stenting is not conclusive. The aim of this multicenter, randomized trial is to evaluate the effect of intraductal RFA prior to bile duct stenting in patients with unresectable perihilar or ductal CCA undergoing palliative systemic therapy.

METHODS/DESIGN

ACTICCA-2 is a multicenter, randomized, controlled, open-label, investigator-initiated trial. 120 patients with perihilar or ductal CCA with indication for biliary stenting and systemic therapy will be randomized 1:1 to receive either RFA plus bile duct stenting (interventional arm) or bile duct stenting alone (control arm). Patients will be stratified by trial site and tumor location (perihilar vs. ductal). Both arms receive palliative systemic treatment according to the local standard of care determined by a multidisciplinary tumorboard. The primary endpoint is time to first biliary event, which is determined by an increase of bilirubin to > 5 mg/dl and/or the occurrence of cholangitis leading to premature stent replacement and/or disruption of chemotherapy. Secondary endpoints include overall survival, safety according to NCI CTCAE v5, quality of life assessed by questionnaires (EORTC QLQ-C30 and QLQ-BIL21), clinical event rate at 6 months after RFA and total days of over-night stays in hospital. Follow-up for the primary endpoint will be 6 months, while survival assessment will be continued until end of study (maximum follow-up 30 month). All patients who are randomized and who underwent endoscopic stenting will be used for the primary endpoint analysis which will be conducted using a cause-specific Cox proportional hazards model with a frailty for trial site and fixed effects for the treatment group, tumor location, and stent material.

DISCUSSION

ACTICCA-2 is a multicenter, randomized, controlled trial to assess efficacy and safety of adding biliary RFA to bile duct stenting in patients with CCA receiving palliative systemic treatment.

TRIAL REGISTRATION

The study is registered with ClinicalTrials.gov (NCT06175845) and approved by the local ethics committee in Hamburg, Germany (2024-101232-BO-ff). This manuscript reflects protocol version 1 as of January 9th, 2024.

Consensus statements on endoscopic radiofrequency ablation for malignant biliary strictures

Endoscopy-guided endobiliary radiofrequency ablation has emerged as a novel treatment for malignant biliary strictures in recent years. When combined with biliary stenting and systemic chemotherapy, it can effectively postpone local tumor progression, improve patient's quality of life, and prolong their survival, which is mainly indicated for patients with inoperable extrahepatic cholangiocarcinoma and ampullary cancer. Based on the existing clinical evidence, the Digestive Endoscopology Branch of Chinese Medical Association, the Digestive Endoscopy Professional Committee, Endoscopic Physicians Branch of Chinese Medical Doctor Association, and the National Clinical Research Center for Digestive Diseases (Shanghai) organized relevant experts to discuss the indications, contraindications, technical operation specifications, and prevention and treatment of the complications during endoscopy-guided endobiliary radiofrequency ablation. Consensus statements were established, trying to provide references for standard treatment of malignant biliary tumors in clinical practice.

Endoluminal radiofrequency ablation in patients with malignant biliary obstruction: a randomised trial

BACKGROUND

Endoluminal radiofrequency ablation (RFA) has been promoted as palliative treatment for patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC) in order to improve biliary drainage and eventually prolong survival. No high level evidence is, however, available on this technique.

DESIGN

In this randomised controlled study, we compared endoluminal RFA plus stenting with stenting alone (control group) in patients with malignant biliary obstruction; metal stents were primarily placed. Primary outcome was overall survival; secondary outcomes were stent patency, quality of life and adverse events. In a superiority design, survival was assumed to be doubled by RFA as compared with 6.4 months in the control group (n=280).

RESULTS

A total of 161 patients (male:female 90:71, mean age 71±9 years) were randomised before recruitment was terminated for futility after an interim analysis. Eighty-five patients had CCA (73 hilar, 12 distal) and 76 had pancreatic cancer. There was no difference in survival in both subgroups: for patients with CCA, median survival was 10.5 months (95% CI 6.7 to 18.3) in the RFA group vs 10.6 months (95% CI 9.0 to 24.8), p=0.58)) in the control group. In the subgroup with pancreatic cancer, median survival was 6.4 months (95% CI 4.3 to 9.7) for the RFA vs 7.7 months (95% CI 5.6 to 11.3), p=0.73) for the control group. No benefit was seen in the RFA group with regard to stent patency (at 12 months 40% vs 36% in CCA and 66% vs 65% in PDAC), and quality of life was unchanged by either treatment and comparable between the groups. Adverse events occurred in seven patients in each groups.

CONCLUSION

A combination of endoluminal RFA and stenting was not superior to stenting alone in prolonging survival or improving stent patency in patients with malignant biliary obstruction.

TRIAL REGISTRATION NUMBER

NCT03166436.

Impact of endobiliary radiofrequency ablation on survival of patients with unresectable cholangiocarcinoma: a narrative review

Cholangiocarcinoma (CCA) is a rare cancer originating from the biliary epithelium and accounts for about 3% of all gastrointestinal malignancies. Unfortunately, the majority of patients are not eligible for surgical resection at the time of diagnosis, because of the locally advanced stage or metastatic disease. The overall survival time of unresectable CCA is generally less than 1 year, despite current chemotherapy regimens. Biliary drainage is often required as a palliative treatment for patients with unresectable CCA. Recurrent jaundice and cholangitis tend to occur because of reobstruction of the biliary stents. This not only jeopardizes the efficacy of chemotherapy, but also causes significant morbidity and mortality. Effective control of tumor growth is crucial for prolonging stent patency and consequently patient survival. Recently, endobiliary radiofrequency ablation (ERFA) has been experimented as a treatment modality to reduce tumor mass, and delay tumor growth, extending stent patency. Ablation is accomplished by means of high-frequency alternating current which is released from the active electrode of an endobiliary probe placed in a biliary stricture. It has been shown that tumor necrosis releases intracellular particles which are highly immunogenic and activate antigen-presenting cells, enhancing local immunity directed against the tumor. This immunogenic response could potentially enhance tumor suppression and be responsible for improved survival of patients with unresectable CCA who undergo ERFA. Several studies have demonstrated that ERFA is associated with an increased median survival of approximately 6 months in patients with unresectable CCA. Furthermore, recent data support the hypothesis that ERFA could ameliorate the efficacy of chemotherapy administered to patients with unresectable CCA, without increasing the risk of complications. This narrative review discusses the results of the studies published in recent years and focuses on the impact that ERFA could have on overall survival of patients with unresectable cholangiocarcinoma.

Efficacy and Safety of Radiofrequency Ablation Plus Stent Versus Stent-alone Treatments for Malignant Biliary Strictures: A Systematic Review and Meta-analysis

BACKGROUND/AIMS

Malignant biliary strictures (MBS) are very aggressive and cannot be diagnosed in the early stages due to their asymptomatic nature. Stenting the stricture area of the biliary tree is palliative treatment but has poor survival time. Radiofrequency ablation plus stent (RFA+S) have been recently used to improve the survival and stent patency time in patients with MBS. In this systematic review and meta-analysis, we tried to evaluate the efficacy and safety of radiofrequency ablation.

MATERIALS AND METHODS

Study search up to December 2021 was performed in different medical databases such as PubMed, Web of Science, and Cochrane library, etc. We selected eligible studies reporting survival time, stent patency time, and adverse events in patients with MBS. We compare the outcomes of RFA+S and stent-alone treatment groups.

RESULTS

A total of 15 studies (6 randomized controlled trials and 9 observational studies) with 1815 patients were included for meta-analysis of which 701 patients were in RFA+S group and 1114 patients in the stent-alone group. Pooled mean difference of survival time was 2.88 months (95% CI: 1.78-3.97) and pooled mean difference of stent patency time was 2.11 months (95% CI: 0.91-3.30) and clinical success risk ratio was 1.05 (95% CI: 1.01-1.09). Risk ratios for adverse events are given; Bleeding 0.84 (95% CI: 0.34-2.11), abdominal pain 1.06 (95% CI: 0.79-1.40), pancreatitis 0.93 (95% CI: 0.43-2.01), cholangitis 1.07 (95% CI: 0.72-1.59), and stent dysfunction 0.87 (95% CI: 0.70-1.07).

CONCLUSIONS

Radiofrequency ablation is involved in increased survival and stent patency time for MBS patients. With the help of better techniques, adverse events can be limited.

ACG Clinical Guideline: Diagnosis and Management of Biliary Strictures

A biliary stricture is an abnormal narrowing in the ductal drainage system of the liver that can result in clinically and physiologically relevant obstruction to the flow of bile. The most common and ominous etiology is malignancy, underscoring the importance of a high index of suspicion in the evaluation of this condition. The goals of care in patients with a biliary stricture are confirming or excluding malignancy (diagnosis) and reestablishing flow of bile to the duodenum (drainage); the approach to diagnosis and drainage varies according to anatomic location (extrahepatic vs perihilar). For extrahepatic strictures, endoscopic ultrasound-guided tissue acquisition is highly accurate and has become the diagnostic mainstay. In contrast, the diagnosis of perihilar strictures remains a challenge. Similarly, the drainage of extrahepatic strictures tends to be more straightforward and safer and less controversial than that of perihilar strictures. Recent evidence has provided some clarity in multiple important areas pertaining to biliary strictures, whereas several remaining controversies require additional research. The goal of this guideline is to provide practicing clinicians with the most evidence-based guidance on the approach to patients with extrahepatic and perihilar strictures, focusing on diagnosis and drainage.

Impact of endobiliary radiofrequency ablation on biliary drainage in patients with malignant biliary strictures treated with uncovered self-expandable metal stents: a randomized controlled multicenter trial

BACKGROUND AND AIMS

Endobiliary radiofrequency ablation (RFA), usually combined with endoscopic stent insertion, is a simple procedure with the potential to improve stent patency and patient survival for malignant biliary obstruction. We conducted this randomized multicenter trial to evaluate the impact of RFA on stent patency.

METHODS

Eighty-six patients with malignant biliary obstruction and nonresectable tumors (pancreatic carcinoma, cholangiocarcinoma, or metastases) were included and randomly assigned to receive a self-expandable metal stent (SEMS) only (n = 44) or RFA followed by SEMS insertion (RFA+SEMS, n = 42). The primary outcome measure was stent patency after 3 and 6 months; secondary outcome measures were patient survival and early adverse events within 30 days.

RESULTS

Technical success rates for RFA and stent insertion were 100% and 98.8%, respectively. Stent patency after 3 and 6 months did not differ significantly between groups (RFA+SEMS group, 73.1% and 33.3%, respectively; SEMS-only group, 81.8% and 52.4%, respectively; P = .6). Similarly, the addition of RFA did not impact overall survival (hazard ratio, .72; P = .389 for RFA+SEMS). The adverse event rate in the RFA+SEMS group was 10.5% compared with 2.3% in the SEMS-only group, without a statistically significant difference (P = .18).

CONCLUSIONS

RFA as an addition to SEMS implantation had no positive impact on patency rate or survival. (Clinical trial registration number: DRKS00018993.).

Endoscopic management of benign and malignant hilar stricture

Management of hilar strictures pose a significant challenge for endoscopists. Several strategies have been demonstrated in the last decade beyond decompression, however, there remains controversy and minimal consensus in the literature. This review seeks to summarize the current literature and discuss emerging therapies, such as photodynamic therapy and radiofrequency ablation.

Endoscopic Management of Pancreatobiliary Malignancies

Pancreatobiliary malignancies have poor prognosis, and many patients are inoperable at the time of diagnosis. When surgical resection is impossible, systemic chemotherapy or radiotherapy is traditionally conducted with trial of immunotherapy or gene therapy lately. With the rapid development of endoscopic instruments and accessories in recent years, not only endoscopic early detection, characterization, and staging but also endoscopic palliative management of the pancreatobiliary malignancies is expanding the horizons. Endoscopic management is often preferred due to similar efficacy to surgical management with less morbidity. Here, we review the methodology and treatment outcome of various endoscopic management strategies in pancreatobiliary malignancies including endoscopic complication management, local palliative therapy, endoscopy-assisted therapy, and pain control utilizing endoscopic retrograde cholangiopancreatography or endoscopic ultrasound.

Endoscopic radiofrequency ablation may improve overall survival in patients with inoperable ampullary carcinoma

OBJECTIVES

Patients with advanced ampullary carcinoma (AC) who are unsuitable for surgery are most likely to have poor outcomes. The role of endoscopic radiofrequency ablation (RFA) in this population has not been fully defined. We aimed to assess the short- and long-term outcomes of RFA in a large cohort of AC patients.

METHODS

In this retrospective study, data of consecutive patients with pathologically proven AC who underwent successful endobiliary RFA and/or stent placement were collected. All patients did not undergo surgical resection. The primary outcome was overall survival (OS). The secondary outcomes included clinical success and adverse events.

RESULTS

A total of 85 patients, 50 in the RFA plus stenting group and 35 in the stenting alone group, were identified. The median OS was significantly longer in the RFA group than in the stenting alone group (16.9 vs. 9.8 months, P < 0.001). In multivariable Cox analysis, RFA (hazards ratio 0.408; 95% confidence interval 0.235-0.706; P = 0.001) was the only independent OS predictor. Eight patients with stage II tumors, exclusively from the RFA group, survived for more than 3 years. Clinical success was comparable between the two groups (96% vs. 100%, P = 0.231). Early adverse events between the two groups were similar (10% vs. 2.9%, P = 0.206); however, late biliary/pancreatic stenoses occurred in three RFA patients who were successfully managed with endoscopic interventions.

CONCLUSIONS

Endoscopic RFA appears to prolong patients' survival with acceptable safety; it may therefore be a feasible treatment option for patients with inoperable ampullary cancers.

Impact of regular additional endobiliary radiofrequency ablation on survival of patients with advanced extrahepatic cholangiocarcinoma under systemic chemotherapy

Prognosis of patients with advanced extrahepatic cholangiocarcinoma (eCCA) is poor. The current standard first-line treatment is systemic chemotherapy (CT) with gemcitabine and a platinum derivate. Additionally, endobiliary radiofrequency ablation (eRFA) can be applied to treat biliary obstructions. This study aimed to evaluate the additional benefit of scheduled regular eRFA in a real-life patient cohort with advanced extrahepatic cholangiocarcinoma under standard systemic CT. All patients with irresectable eCCA treated at University Hospital Bonn between 2010 and 2020 were eligible for inclusion. Patients were stratified according to treatment: standard CT (n = 26) vs. combination of eRFA with standard CT (n = 40). Overall survival (OS), progression free survival (PFS), feasibility and toxicity were retrospectively analyzed using univariate and multivariate approaches. Combined eRFA and CT resulted in significantly longer median OS (17.3 vs. 8.6 months, p = 0.004) and PFS (12.9 vs. 5.7 months, p = 0.045) compared to the CT only group. While groups did not differ regarding age, sex, tumor stage and chemotherapy treatment regimen, mean MELD was even higher (10.1 vs. 6.7, p = 0.015) in the eRFA + CT group. The survival benefit of concomitant eRFA was more evident in the subgroup with locally advanced tumors. Severe hematological toxicities (CTCAE grades 3 – 5) did not differ significantly between the groups. However, therapy-related cholangitis occurred more often in the combined treatment group (p = 0.031). Combination of eRFA and systemic CT was feasible, well-tolerated and could significantly prolong survival compared to standard CT alone. Thus, eRFA should be considered during therapeutic decision making in advanced eCCA.

Radiofrequency ablation in the management of primary hepatic and biliary tumors

In the United States, 80%-90% of primary hepatic tumors are hepatocellular carcinomas and 10%-15% are cholangiocarcinomas (CCA), both with high mortality rate, particularly CCA, which portends a worse prognosis. Traditional management with surgery has good outcomes in appropriately selected patients; however, novel ablative treatment options have emerged, such as radiofrequency ablation (RFA), which can improve the prognosis of both hepatic and biliary tumors. RFA is aimed to generate an area of necrosis within the targeted tissue by applying thermal therapy via an electrode, with a goal to completely eradicate the tumor while preserving surrounding healthy tissue. Role of RFA in management of hepatic and biliary tumors forms the focus of our current mini-review article.

Updated evidence on the clinical impact of endoscopic radiofrequency ablation in the treatment of malignant biliary obstruction

Endoscopic biliary radiofrequency ablation (RFA) was recently developed as a novel adjunctive procedure and a promising therapeutic option in patients with malignant biliary obstruction (MBO). RFA can achieve local tumor control, resulting in improved biliary stent patency and a potential survival benefit. However, the efficacy of biliary RFA remains controversial, and previous studies have shown conflicting results. At present, extrahepatic cholangiocarcinoma is considered the condition most effectively treated by biliary RFA, but there is limited research even on this point. Further, limitations of RFA associated with the devices used during the procedure are an important subject of discussion. In addition to further well-designed clinical trials, development of innovative devices is warranted to investigate and conclusively establish the usefulness of biliary RFA. In this review we summarize the updated evidence regarding the use of endoscopic biliary RFA for MBO and discuss issues that should be addressed in future studies.

Ablative therapies of the biliary tree

Cholangiocarcinoma, a malignancy of the epithelial cells in the intrahepatic or extrahepatic biliary tree, is often diagnosed at later stages. Median survival duration ranges from 3 to 9 months with a less than ten percent 5-year survival rate. Thus, often treatment strategies are aimed more towards palliation instead of cure. With the majority of patients presenting with unresectable disease at the time of diagnosis, surgical intervention is not feasible, making less invasive endoscopic therapies more suitable. Initially, biliary stents were utilized for biliary decompression to mitigate cholestatic symptoms and prevent cholangitis; however, this strategy did not prove to provide significant survival benefit. Therefore, efforts to treat the tumor burden itself in addition to maintaining biliary patency became a focus of innovation and research in the endoscopic field. This study has led to the advent of therapies such as photodynamic therapy, radiofrequency ablation, and intraluminal brachytherapy. These options combined with biliary stenting have shown to not only offer the benefit of biliary decompression, but also to potentially improve stent patency and survival. Further, there is an anti-tumor effect of each of these modalities, portending an additional benefit in this subset of patients. Despite numerous retrospective and prospective studies assessing these ablative therapies, there is still a paucity of appropriately powered randomized controlled trials, and further research has yet to be done in the field. This review details the current literature entailing endobiliary ablative strategies.

[Recent Updates on Endoscopic Retrograde Cholangiography-guided Intraductal Radiofrequency Ablation for Malignant Biliary Stricture]

Malignant biliary strictures are caused by pancreatobiliary cancer and other metastatic malignancies. Most of them are unresectable at diagnosis with a dismal prognosis. Various new ablation methods have been introduced. Of them, ERCP-guided intraductal radiofrequency ablation (ID-RFA) appears to be the most promising minimally invasive endoscopic treatment by delivering a high-frequency alternating current to the target tissue, leading to coagulative necrosis. Thus far, many studies have provided evidence that ERCP-guided ID-RFA is a safe, feasible, and effective treatment modality for stent patency and overall survival. Compared to other ablation treatments, ERCP-guided ID-RFA has several advantages, including ease of delivery, controlled application of thermal energy, low cost, and fewer systemic side effects with an acceptable safety profile. Therefore, ERCP-guided ID-RFA can be considered an adjunctive treatment for the palliation of unresectable malignant biliary strictures. On the other hand, the decision of local ablation treatment should be individualized by multidisciplinary team support due to the lack of comparative studies.

Endoscopic radiofrequency ablation for malignant biliary obstruction

Cholangiocarcinoma and pancreatic cancer are the most common causes of malignant biliary obstruction. The majority of patients are diagnosed at a late stage when surgical resection is rarely possible. In these cases, palliative chemotherapy and radiotherapy provide only limited benefit and are associated with poor survival. Radiofrequency ablation (RFA) is a procedure for locoregional control of tumours, whereby a high-frequency alternating current turned into thermal energy causes coagulative necrosis of the tissue surrounding the catheter. The subsequent release of debris and tumour antigens by necrotic cells can stimulate local and systemic immunity. The development of endoluminal RFA catheters has led to the emergence of endoscopically delivered RFA, a treatment mainly used for malignant biliary strictures to prolong survival and/or stent patency. Other indications include recanalisation of occluded biliary stents and treatment of intraductal ampullary adenoma or benign biliary strictures. This article presents a comprehensive review of endobiliary RFA, mainly focusing on its use in patients with malignant biliary obstruction. The available data suggest that biliary RFA may be a promising modality, having positive impacts on survival and stent patency and boasting a reasonable safety profile. However, further studies with better characterised and stratified patient populations are needed before the method becomes accepted within routine clinical practice.

Feasibility of balloon-based endobiliary radiofrequency ablation under cholangioscopy guidance in a swine model

Although endobiliary radiofrequency ablation (RFA) has demonstrated considerable potential for the treatment of biliary strictures, conventional catheter RFA has several limitations. This study aimed to evaluate the feasibility of a novel cholangioscopy (CS)-guided balloon-based RFA procedure in vivo using a swine model. CS-guided balloon-RFA was performed under endoscopic retrograde cholangiography guidance at target temperatures of 60 ℃ or 70 ℃, which were maintained for 60 s. We evaluated the technical feasibility, adverse events, and histological effects associated with the procedure. Twelve sites were ablated in seven miniature pigs. The CS-guided balloon-RFA procedure was technically successful in all cases without any hindrance. Mucosal changes could be detected during RFA, and the ablation area was identified on CS. Necropsy was performed in four pigs on the same day as the procedure: the tissue samples showed coagulative necrosis, and the entire internal circumference of the bile duct was uniformly ablated. The mean lengths of the ablation area in the samples ablated at 60 °C and 70 °C were 20.64 and 22.18 mm, respectively, while the mean depths were 3.46 and 5.07 mm, respectively. The other three pigs were reared and euthanized and autopsied 35 days after the procedure. The site to be ablated had replaced the granulation tissue and fibrotic changes. No adverse events were observed in any case. CS-guided balloon-RFA appears to be a promising option for treating biliary strictures. This preliminary study could pave the way for the evaluation of this procedure in future human clinical trials.

Endoscopic radiofrequency ablation plus plastic stent placement versus stent placement alone for unresectable extrahepatic biliary cancer: a multicenter randomized controlled trial

BACKGROUND AND AIMS

We sought to compare the efficacy and safety between endoscopic radiofrequency ablation (RFA) and stent placement alone in patients with unresectable extrahepatic biliary cancer (EBC).

METHODS

In this randomized controlled trial, patients with locally advanced or metastatic cholangiocarcinoma (CCA) or ampullary cancer who were unsuitable for surgery were recruited from 3 tertiary centers. Eligible patients were randomly assigned to RFA plus plastic stent placement (RFA group) or plastic stent placement alone (stent placement alone group) in a 1:1 ratio. Both groups underwent 2 scheduled interventions with an interval of approximately 3 months. The primary outcome was overall survival (OS).

RESULTS

Altogether, 174 participants completed the 2 index endoscopic interventions. No significant differences in baseline characteristics were noted between the 2 groups. The median OS was significantly higher in the RFA group (14.3 vs 9.2 months; hazard ratio, .488; 95% confidence interval, .351-.678; P < .001). A survival benefit was also shown in patients with CCA (13.3 vs 9.2 months; hazard ratio, .546; 95% confidence interval, .386-.771; P < .001). However, no significant between-group differences were found in jaundice control or stent patency duration. The postprocedural Karnofsky performance scores were significantly higher in the RFA group until 9 months (all P < .001). Adverse events were comparable between the 2 groups (27.6% vs 19.5%, P = .211), except for acute cholecystitis, which was more frequently observed in the RFA group (9 vs 0, P = .003).

CONCLUSIONS

Compared with stent placement alone, additional RFA may improve OS and quality of life of patients with inoperable primary EBC who do not undergo systemic treatments. (Clinical trial registration number: NCT01844245.).

Effect of endoscopic radiofrequency ablation on the survival of patients with inoperable malignant biliary strictures: A large cohort study

BACKGROUND AND AIMS

Endoscopic radiofrequency ablation (RFA) is an emerging technique for the palliation of inoperable malignant biliary strictures (MBSs). We aimed to systemically investigate the long-term outcome of RFA in a large cohort of patients.

METHODS

We recruited 883 patients with various MBSs who underwent endoscopic interventions at two large-volume centers; 124 patients underwent RFA and stenting, whereas 759 underwent stenting alone. To overcome selection bias, we performed 1:4 propensity score matching (PSM). The main outcome was overall survival (OS).

RESULTS

Following PSM, patients in the RFA group showed significantly longer OS (9.5 months; 95% CI: 7.7-11.3 months) than those in the stenting alone group (6.1 months; 95% CI: 5.6-6.6 months; P < .001). In stratified analyses, the improved OS was only demonstrated in the subgroup of extrahepatic cholangiocarcinoma (11.3 months 95% CI: 10.2-12.4 vs 6.9 months 95% CI: 6.0-7.8; P < .001), but not in the subgroups of gallbladder cancer, hepatocellular carcinoma, intrahepatic cholangiocarcinoma, pancreatic cancer, and other metastatic cancers (all P > .05). The survival benefits were noted only in the patients with non-metastatic cholangiocarcinoma (11.5 vs 7.4 months, P < .001).

CONCLUSIONS

The survival benefits of endoscopic RFA appear to be limited to patients with extrahepatic cholangiocarcinoma without distant metastasis.

The Safety of Radiofrequency Ablation Using a Novel Temperature-Controlled Probe for the Treatment of Residual Intraductal Lesions after Endoscopic Papillectomy

Background/Aims

Treatment of residual intraductal lesions after endoscopic papillectomy for ampullary adenomas is relatively difficult. Few studies have been conducted using intraductal radiofrequency ablation (RFA) in the treatment of such lesions, and no study has aimed to reduce the side effects of excessive heat caused by RFA. Recently, a temperature-controlled RFA probe was developed to avoid excessive heat. This study aimed to investigate the safety of this new RFA probe in the treatment of intraductal lesions of ampullary adenoma.

Methods

Patients who received RFA for residual intraductal lesions after endoscopic papillectomy between November 2017 and June 2019 were retrospectively reviewed. A novel temperature- controlled probe (ELRA) was used for intraductal RFA, and clinical data including adverse events were collected.

Results

Ten patients were included in this study. Intraductal adenomas showed low-grade dysplasia in eight patients and high-grade dysplasia in two patients. The median diameter of intraductal adenomas was 9 mm (range, 5 to 10 mm) in the common bile duct and 5 mm (range, 4 to 11 mm) in the pancreatic duct. Adverse events occurred in three patients (30.0%), of which two were mild pancreatitis and one was asymptomatic biliary stricture. Over a median follow-up period of 253 days, only one patient underwent additional surgery, as the remainder showed no adenomatous lesions on follow-up biopsies.

Conclusions

The new temperature-controlled RFA probe can be used with acceptable safety for the treatment of residual intraductal lesions after endoscopic papillectomy. Further evaluation through future prospective studies is needed.

Palliative Measures with Ethanol Gallbladder Ablation and Endobiliary Radiofrequency Ablation Followed by Endoscopic Biliary Stent Placement in an Advanced Case of Common Bile Duct Cancer: A Case Report

Endobiliary radiofrequency ablation (RFA) is a procedure performed widely to induce locoregional tumor control by the transfer of thermal energy to the lesion and subsequent tumor necrosis. A 72-year-old male with a prior history of acute calculous cholangitis and perforated cholecystitis was admitted to the Kyungpook National University Hospital complaining of fever and nausea. He had an indwelling percutaneous transhepatic gallbladder drainage (PTGBD) catheter from the previous episode of perforated cholecystitis. An abdominal CT scan showed marked dilation of both the intrahepatic and extrahepatic bile ducts. Common bile duct cancer was confirmed histologically after an endobiliary biopsy. A surgical resection was considered to be the initial treatment option. During open surgery, multiple metastatic nodules were present in the small bowel mesentery and anterior abdominal wall. Resection of the tumor was not feasible, so endobiliary RFA was performed prior to biliary stenting. Cholecystectomy was required for the removal of the PTGBD catheter, but the surgical procedure could not be performed due to a cystic ductal invasion of the tumor. Instead, chemical ablation of the gallbladder (GB) with pure ethanol was performed to breakdown the GB mucosa. Palliative treatment for a biliary obstruction was achieved successfully using these procedures. In addition, a PTGBD catheter was removed successfully without significant side effects. As a result, an improvement in the patient's quality of life was accomplished.

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.

International consensus statements for endoscopic management of distal biliary stricture

Distal biliary strictures (DBS) are common and may be caused by both malignant and benign pathologies. While endoscopic procedures play a major role in their management, a comprehensive review of the subject is still lacking. Our consensus statements were formulated by a group of expert Asian pancreatico-biliary interventional endoscopists, following a proposal from the Digestive Endoscopy Society of Taiwan, the Thai Association for Gastrointestinal Endoscopy, and the Tokyo Conference of Asian Pancreato-biliary Interventional Endoscopy. Based on a literature review utilizing Medline, Cochrane library, and Embase databases, a total of 19 consensus statements on DBS were made on diagnosis, endoscopic drainage, benign biliary stricture, malignant biliary stricture, and management of recurrent biliary obstruction and other complications. Our consensus statements provide comprehensive guidance for the endoscopic management of DBS.

Nonsurgical Approaches to Treat Biliary Tract and Liver Tumors

Endoscopic and percutaneous therapies have been shown to prolong life and reduce morbidity for patients with unresectable advanced stages of primary hepatobiliary malignancies. This article reviews pertinent studies published within the last 5 years that involve locoregional techniques to manage hepatocellular carcinoma, perihilar and distal cholangiocarcinoma. A major emphasis is placed on photodynamic therapy, radiofrequency ablation, irreversible electroporation, and microwave ablation. Technical advances, combinational therapies, and postintervention outcomes are discussed. Despite widespread application, high-quality evidence does not show superiority of any particular locoregional technique for treating advanced hepatobiliary cancers.

Initial Experience of ERCP-Guided Radiofrequency Ablation as the Primary Therapy for Inoperable Ampullary Carcinomas

BACKGROUND

Endoscopic ablation of duodenal ampullary malignancy has not been fully assessed.

AIMS

The study aimed to evaluate the efficacy and safety of Endoscopic retrograde cholangiopancreatograpy (ERCP)-guided radiofrequency ablation (RFA) for inoperable ampullary cancer.

METHODS

Patients with inoperable ampullary cancer underwent ERCP-guided RFA from January 2012 to August 2017. RF energy (7-10 W) was delivered using bipolar RFA electrodes under endoscopic guidance. RFAs were repeated every 1-3 months until visible tumor was eliminated. All patients were followed up till June 2018, during which any biliary event was noted and managed endoscopically.

RESULTS

Twenty-three patients underwent a median of two RFA sessions (range 1-6) at a median interval of 56 (range 35-90) days. Among 18 (78.3%) patients who received endoscopic re-evaluations, nine patients showed no remaining lesion and nine showed more than 50% tumor size reduction. During a median follow-up duration of 517 days (range 60-1836 days), eight (34.8%) patients required endoscopic re-interventions. The re-intervention rate at 6 months after RFA was 36.8%. Twelve patients were alive, among whom six required no biliary stenting. The accumulative mean survival was 1081 (95% CI 757.8-1404.0) days. RFA-related adverse events occurred in four cases (7.7%) including mild pancreatitis (1), bleeding (1), and late distal biliary stenosis (2).

CONCLUSION

This pilot study shows that ERCP-guided RFA is safe to use and able to reduce tumor volume and re-interventions in patients with inoperable ampullary cancer.

Ablative therapies for hepatic and biliary tumors: endohepatology coming of age

Ablative therapies refer to minimally invasive procedures performed to destroy abnormal tissue that may arise with many conditions, and can be achieved clinically using chemical, thermal, and other techniques. In this review article, we explore the different ablative therapies used in the management of hepatic and biliary malignancies, namely hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), with a particular focus on radiofrequency ablation (RFA) and photodynamic therapy (PDT) techniques.

Endoscopic Radiofrequency Ablation Prolongs Survival of Patients with Unresectable Hilar Cholangiocellular Carcinoma - A Case-Control Study

The life expectancy of unresectable hilar cholangiocellular carcinomas (CCCs) is very limited and endoscopic radiofrequency ablation (ERFA) of the biliary tract may prolong survival. Our single-center-study retrospectively analysed all CCC cases, in whom ERFAs of the biliary tract were performed between 2012 and 2017 and compared these to historical control cases who received the standard treatment of sole stent application. ERFA was performed in 32 patients with malignant biliary strictures that were mainly caused by Bismuth III and IV hilar CCCs (66%). 14 of these patients received repeated ERFAs, for an overall performance of 54 ERFAs. Stents were applied after examination of all patients (100%). Adverse events occurred in 18.5% of examinations. Case-control analysis revealed that the survival time of cases with unresectable Bismuth type III and IV hilar CCCs (n = 20) treated with combined ERFA and stent application significantly increased compared to controls (n = 22) treated with sole stent application (342 +/- 57 vs. 221 +/- 26 days; p = 0.046). In conclusion, ERFA therapy significantly prolonged survival in patients with unresectable Bismuth type III and IV hilar CCC. As an effective and safe method, ERFA should be considered as a palliative treatment for all these patients.

Inoperable Biliary Tract and Primary Liver Tumors: Palliative Treatment Options

Primary liver tumors are most commonly hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Although surgical resection offers a chance for cure, these tumors generally present at a late, inoperable stage, necessitating an understanding of noncurative and palliative treatment options. These options include ablative therapies, including radiofrequency ablation; intra-arterial therapies, including transcatheter chemoembolization; biliary decompression; radiotherapy; systemic therapies, including traditional chemotherapeutic agents; and molecular therapies, such as sorafenib. Selection of nonoperative treatment depends on patient and tumor factors as well as institutional resources and expertise.

Endoscopic radiofrequency biliary ablation treatment: A comprehensive review

Radiofrequency ablation (RFA) functions by delivering thermal energy within tissue, the result of a high-frequency alternating current released from an active electrode, leading to coagulative necrosis and cellular death. Recently, a biliary catheter working on a guidewire has been developed and a number of studies have so far been carried out. The present article provides a comprehensive review of the literature on the results of the use of RFA for the clinical management of patients with unresectable malignant biliary strictures, benign biliary strictures, and residual adenomatous tissue in the bile duct after endoscopic papillectomy. Available data show that biliary RFA treatment is a promising adjuvant therapy in patients with unresectable malignant biliary obstruction. The procedure is safe, well tolerated and improves stent patency and survival, even though more studies are warranted. In patients with residual endobiliary adenomatous tissue after endoscopic papillectomy, a significant rate of neoplasia eradication after a single RFA session has been reported, thus favoring this treatment over surgical intervention. In these patients, as well as in those with benign biliary strictures, dedicated probes with a short electrode able to focus the RF current on the short stenosis are needed to expand RFA treatment for these indications.

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.

Endobiliary radiofrequency ablation for distal extrahepatic cholangiocarcinoma: A clinicopathological study

BACKGROUND

Most patients with distal extrahepatic cholangiocarcinoma have developed jaundice or cholangitis at the time of initial diagnosis, which can delay surgery. We aim to evaluate the actual EB-RFA ablation volume and validated the clinical feasibility of preoperative endobiliary radiofrequency ablation (EB-RFA) for resectable distal extrahepatic cholangiocarcinoma.

METHODS

The medical records of patients who underwent EB-RFA from July 2016 to June 2017 at a single tertiary academic medical center were reviewed. Inclusion criteria were patients with resectable distal extrahepatic cholangiocarcinoma who required preoperative biliary decompression. Clinical outcomes of EB-RFA were reviewed retrospectively and the surgical specimens were reevaluated.

RESULTS

Of the eight patients who required a delayed operation, preoperative EB-RFA was successfully performed without serious complications including peritonitis, hemobilia, or perforation. Although curative resection was attempted in all patients, one patient underwent open and closure due to hepatic metastasis. Seven patients underwent curative surgical resection and the histology revealed that median maximal ablation depth was 4.0 mm (range, 1-6) and median effective ablation length (histological ablation length/fluorosocopic ablation length) was 72.0% (range, 42.1-95.3).

CONCLUSIONS

EB-RFA partially ablated human cancer tissue and preoperative EB-RFA might be a safe and feasible in patients with distal extrahepatic cholangiocarcinoma who require a delayed operation. Ablation of the target lesion longer than the estimated length by fluoroscopy may improve the efficacy of EB-RFA.

New Indications for Endoscopic Radiofrequency Ablation

Radiofrequency ablation (RFA) is a well-established treatment for several benign, premalignant, and malignant disorders. Although the role of RFA has been clearly defined, new indications for luminal and extraluminal applications of endoscopic RFA-directed therapies have emerged. RFA has recently produced promising results in patients with a variety of gastrointestinal and hepatopancreatobiliary pathologies. For example, endoscopic RFA has been used to treat patients with gastric antral vascular ectasia, chronic radiation proctitis, malignant biliary strictures, and ampullary adenomas with intraductal extension. Furthermore, endoscopic ultrasound-guided RFA appears to be an effective, minimally invasive treatment for ablation of solid and cystic lesions-particularly in the pancreas. We review the newer indications for RFA and discuss potential limitations of endoscopic RFA.

Endoscopic Management of Pancreatobiliary Neoplasms

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are the mainstays of interventional endoscopic practice. EUS occupies a central role in the diagnosis of pancreatobiliary neoplasms and offers a platform for a wide range of direct tumor therapies. Initial steps have demonstrated the feasibility of such applications in animal models and pilot studies. Larger clinical trials and incorporation of EUS-based therapies into cooperative cancer studies might demonstrate an impact in the clinical prognosis of patients with pancreatic cancer. ERCP plays an important role in elucidating indeterminate biliary strictures and in treating patients with malignant biliary obstruction who are symptomatic or have borderline-resectable or unresectable disease. ERCP-directed ablative therapies enable neoadjuvant and palliative intervention in patients with malignant biliary obstruction, in particular perihilar cholangiocarcinoma. Additional comparative, multicenter studies are needed to better understand the safety and efficacy of endobiliary brachytherapy, photodynamic therapy, and radiofrequency ablation in patients with pancreatobiliary malignancies.

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.

Ex vivo human bile duct radiofrequency ablation with a bipolar catheter

BACKGROUND

Management of the primary and secondary tumors of the bile ducts still remains as a major clinical challenge. Radiofrequency (RF) ablation (RFA) of these tumors is feasible but the effect of RF energy on the human common bile duct (CBD) and surrounding tissues has not been investigated. This pilot study aimed to determine the relationship between RF energy and the depth of ablation in the normal human CBD.

METHODS

The study was performed on fresh ex vivo human biliary-pancreatic tissue which had been resected for a pancreatic cyst or mass. The study was conducted within 15 min after resection. A bipolar Habib RFA catheter was placed into the middle of the intact CBD, and three different (5, 7, 10 W) power settings were applied over a 90-s period by an RF generator. Gross and histological examinations were performed. The depth of coagulation necrosis in CBD and the effect of RFA on CBD wall and surrounding pancreas tissue were determined by microscopic examination.

RESULTS

The study included eight tissue samples. 5 W power was applied to three sites and RFA caused only focal epithelial necrosis limited to the CBD mucosa. 7 and 10 W were applied to five sites and coagulation necrosis occurred in all cases. Microscopically, necrosis was transmural, involved accessory bile duct glands, and extended to the surrounding pancreatic tissue in four of these cases. Macroscopically, RFA resulted in circumferential white-yellowish color change extending approximately 2 cm of the CBD.

CONCLUSION

Bipolar RF energy application with 5 W resulted in limited ablation on CBD wall. However, 7 and 10 W generated tissue necrosis which extended through the CBD wall and into surrounding pancreas tissue. Endoscopic biliary RFA is an effective technique for local biliary tissue ablation but the use of high energy may injure surrounding tissue.

Evaluation of the safety of endoscopic radiofrequency ablation for malignant biliary stricture using a digital peroral cholangioscope (with videos)

BACKGROUND AND AIM

The clinical impact of catheter-based radiofrequency ablation (RFA) under endoscopic retrograde cholangiopancreatography (ERCP) guidance has recently been reported; however, severe adverse events have also been noted. If tumor is not present in the biliary tract, severe adverse events such as perforation or bleeding as a result of vessel injury around the biliary tract may occur. In addition, the effectiveness of RFA may not be sufficient based solely on radiographic guidance. The aim of the present study was to evaluate the actual feasibility of intraductal RFA by peroral cholangioscope (POCS) evaluation before/after RFA.

METHODS

In this retrospective study carried out between July and September 2016, consecutive patients who underwent RFA for malignant biliary stricture and POCS evaluation before/after RFA were enrolled. Primary endpoint of this study was technical feasibility of RFA, which was evaluated by POCS. Secondary endpoints were rates and types of adverse event.

RESULTS

A total of 12 consecutive patients were retrospectively enrolled in this study. Stent placement using uncovered metal stents had been previously done in six patients before RFA. Tumor was seen in the biliary tract in all patients. RFA was technically successful in all patients, and clinical success was confirmed in all patients by POCS imaging. Adverse events were seen in only one patient. Median stent patency was 154 days.

CONCLUSIONS

RFA for malignant biliary stricture may be safe. To confirm the feasibility and efficacy of RFA, additional cases, prospective studies, and a comparison study between with and without endobiliary RFA are needed.

Radiofrequency ablation for management of malignant biliary obstruction: a single-center experience and review of the literature

BACKGROUND

Radiofrequency ablation (RFA) causes coagulative necrosis of tissue and may be beneficial prior to biliary stenting. We report our experience using RFA for malignant biliary obstruction and review the literature.

METHODS

Retrospective analysis of all patients undergoing RFA for malignant biliary obstruction over the last two years. Success, complications and re-intervention following RFA were assessed. Controls were age, sex and disease matched who had stenting alone.

RESULTS

31 patients were included and 15 patients underwent biliary RFA prior to stenting (median age 78 years, 8 females). 14 patients had pancreatic cancer, 13 cholangiocarcinoma (6 hilar lesions) and 4 malignant disease invading the bile duct. Adverse events included acute pancreatitis (n = 2) and bacteremia in (n = 1). Median duration of intervention free survival was 220 days in the RFA group compared to 106.5 days in controls (hazard ratio 2.4, 95% CI 1.1 - 5.3, p = 0.025). Multivariable Cox proportional hazard analysis showed survival was associated with RFA (hazard ratio 2.55, 95% CI 1.09-5.96, p = 0.026) but not age, site or type of malignancy.

CONCLUSION

Biliary RFA is a technically feasible with a low adverse event rate and is associated with increased survival. Multi-centre randomized controlled trials are required.

Endoscopic radiofrequency ablation may be preferable in the management of malignant biliary obstruction: A systematic review and meta-analysis

OBJECTIVE

Endoscopic biliary radiofrequency ablation (RFA) has been increasingly used to treat unresectable malignant biliary obstruction (MBO). We aimed to perform this systematic review and meta-analysis to evaluate the efficacy and safety for the treatment of malignant biliary obstruction (MBO) and its impact on patient's survival.

METHODS

A comprehensive search of the Cochrane Library, PubMed and EMBASE databases was conducted. A meta-analysis was performed by extracting the data from the included studies with regard to technical effectiveness, overall survival, adverse events and mortality of endoscopic RFA.

RESULTS

A total of nine studies comprising 263 patients with MBO were included in the analysis. There was a significant increase in the diameter of stricture (3.446 mm, 95% confidence interval [CI] 3.356-3.536 mm) after the endoscopic biliary RFA. The overall survival time was 9.62 months, with pooled 30-day, 90-day and 2-year mortality rates of 2% (95% CI 0.5-5.9%), 21% (95% CI 5-37%), and 48% (95% CI 37-59%), respectively. The pooled rate of adverse events was 17% (95% CI 10-25%), and most complications were mild and managed conservatively. Severe adverse events occurred in three patients (two deaths due to hemobilia and one with partial liver infarction).

CONCLUSIONS

Endoscopic biliary RFA is effective and generally safe in the management of unresectable biliary malignancies, and may improve patients' overall survival. Prospective, randomized controlled studies are required to further support the results.

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

Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with self-expanding metal stents (SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency (RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation (RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reports have also highlighted a potential curative role of RFA in small pancreatic tumours and benign conditions, such as ductal extension of ampullomas, intrahepatic adenomas or non-tumoural biliary strictures. These newest indications also deserve further examination in larger series of studies.

Radiofrequency ablation for pancreatobiliary disease

PURPOSE OF REVIEW

Radiofrequency ablation (RFA) has been recognized for its potential in palliative treatment for pancreatic cancer as well as malignant biliary strictures. The purpose of this review is to describe the technology, endoscopic technique, and reported outcomes of endoscopic RFA in the management of malignant biliary strictures and unresectable pancreatic cancer.

RECENT FINDINGS

Intraductal biliary RFA is safe and feasible and appears to confer a survival advantage. Pancreatic endoscopic ultrasound-guided RFA is a promising new technique and may result in either resolution of tumor or reduction in size.

SUMMARY

Intraductal biliary RFA and pancreatic endoscopic ultrasound-guided RFA are important modalities in malignant biliary obstruction and unresectable pancreatic cancer. Intraductal biliary RFA should be used as an adjunct to biliary stenting. Further trials are needed to determine if RFA leads to a benefit in pancreatic cancer treatment. Two prospective trials are currently underway to determine if intraductal biliary RFA indeed confers a survival advantage in malignant obstruction.