Intraductal endoscopic radiofrequency ablation for the treatment of hilar non-resectable malignant bile duct obstruction

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.

Assessment of safety and adverse events in endoscopic radiofrequency ablation for malignant biliary obstruction

Background

Endoscopic radiofrequency ablation (RFA) is used for the treatment of unresectable malignant biliary obstruction (MBO). The postoperative adverse events associated with RFA treatment have gained importance.

Objective

To investigate the early adverse events and their risk factors associated with RFA for the treatment of MBO.

Design

Observational retrospective study.

Methods

We collected data from patients diagnosed with MBO and treated with endoscopic RFA at our hospital between January 2010 and June 2022. Based on the collected data, the patients were divided into two groups: the adverse event group and the nonadverse event group. Early postoperative adverse events were recorded, and risk factors were assessed.

Results

One hundred and twenty patients with MBO underwent endoscopic RFA, with 20 developing adverse events (16.6%; 20/120). Among these, 13 patients (10.8%) developed biliary infection after RFA treatment, while 7 (5.8%) developed acute pancreatitis, and no bleeding or perforation occurred. Type 2 diabetes mellitus, bile duct stricture length >2.5 cm, segmental RFA, and the proportion of patients receiving single stent drainage were all significantly greater in the adverse event group compared to the nonadverse event group (p < 0.05). The results of the logistic regression analysis showed that type 2 diabetes, segmental RFA, and single stent drainage were the three independent risk factors for getting a biliary infection after RFA therapy.

Conclusion

Unresectable MBO combined with type 2 diabetes mellitus, segmental RFA, and postoperative single stent drainage can be the risk factors for adverse events after RFA. More attention should be paid to patients with multiple risk factors and preventive measures should be taken.

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.

Emerging Technologies in Endoscopy for Gastrointestinal Neoplasms: A Comprehensive Overview

Gastrointestinal neoplasms are a growing global health concern, requiring prompt identification and treatment. Endoscopic procedures have revolutionized the detection and treatment of gastrointestinal tumors by providing accurate, minimally invasive methods. Early-stage malignancies can be treated with endoscopic excision, leading to improved outcomes and increased survival rates. Precancerous lesions, like adenomatous polyps, can be prevented by removing them, reducing cancer occurrence and death rates. Advanced techniques like chromoendoscopy, narrow-band imaging, and confocal laser endomicroscopy improve the ability to see the mucosa surface and diagnose conditions. Artificial Intelligence (AI) applications in endoscopy can enhance diagnostic accuracy and predict histology outcomes. However, challenges remain in accurately defining lesions and ensuring precise diagnosis and treatment selection. Molecular imaging approaches and therapeutic modalities like photodynamic therapy and endoscopic ultrasonography-guided therapies hold potential but require further study and clinical confirmation. This study examines the future prospects and obstacles in endoscopic procedures for the timely identification and treatment of gastrointestinal cancers. The focus is on developing technology, limits, and prospective effects on clinical practice.

Local Control of Distal Cholangiocarcinoma With Radiofrequency Ablation at Endoscopic Retrograde Cholangiopancreatography

Distal cholangiocarcinoma (CCA) can pose diagnostic and therapeutic challenges, often leading to a poor prognosis. While curative resection is viable for a minority in the early stage, we report a case of successful endoscopic therapy. A 79-year-old patient, diagnosed with early-stage extrahepatic CCA, opted out of surgery and chemotherapy. Instead, he pursued a treatment strategy involving serial radiofrequency ablation with stent exchange at endoscopic retrograde cholangiopancreatography. The patient achieved remission, showcasing the potential for local control of distal CCA through radiofrequency ablation and covered self-expanding metal stents. This alternative becomes particularly relevant for patients unsuitable for surgery or chemotherapy and those who decline it.

Impact of temperature-controlled endobiliary radiofrequency ablation for inoperable hilar cholangiocarcinoma: A propensity score-matched analysis

Background and study aims Endobiliary radiofrequency ablation (RFA) can be an effective palliative treatment, but few studies have evaluated its outcomes for malignant obstruction in the hilar bile duct, which has a thin wall and complex duct-vascular contacts. We evaluated the efficacy and safety of temperature-controlled endobiliary RFA, which can reduce the risk of unintentional thermal injury by maintaining the temperature of the ablation segment, in the treatment of inoperable hilar cholangiocarcinoma (CCA). Patients and methods After propensity score matching, 64 patients with inoperable hilar CCA were categorized to the RFA + stent group (endobiliary RFA with stenting; n=32) or stent-only group (stenting only; n=32). The evaluated outcomes were the median time to recurrent biliary obstruction (RBO), overall survival (OS), and adverse events (AEs). Results Technical success was achieved in all patients. The clinical success rate was 93.8% in the RFA + stent group and 87.5% in the stent-only group ( P =0.672). The median time to RBO was 242 days in the RFA + stent group and 168 days in the stent-only group ( P =0.031). The median OS showed a non-significant tendency to be higher in the RFA + stent group (337 versus 296 days; P =0.260). Overall AE rates were comparable between the two groups (12.5% vs 9.4%, P =1.000). Conclusions Temperature-controlled endobiliary RFA resulted in favorable stent patency without increasing the rate of AEs but it did not significantly increase OS in patients with inoperable hilar CCA (Clinical trial registration number: KCT0008576).

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.

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.

Is endoscopic radiofrequency ablation plus stent placement superior to stent placement alone for the treatment of malignant biliary obstruction? A systematic review and meta-analysis

OBJECTIVE

Malignant biliary obstruction (MBO) is a rare disease with a poor prognosis. Recent studies have shown that endoscopic radiofrequency ablation (ERFA) may improve survival. We conducted a systematic review and meta-analysis of the efficacy of ERFA in combination with biliary stent placement for the treatment of MBO.

METHODS

The study was registered in INPLASY (number 202340096). The PubMed, Cochrane Library, Web of Science, and Embase databases were searched from inception to April 2023. We selected studies comparing the efficacy of ERFA plus stent placement with stent placement alone. The primary outcomes were pooled hazard ratios (HRs) for overall survival and stent patency; the secondary outcomes were the odds ratios (ORs) for adverse events.

RESULTS

Eleven studies (four randomized controlled trials and seven observational studies) were included in the meta-analysis. Pooled analysis showed a difference in survival time between the two groups (HR 0.65, 95% confidence interval [CI] 0.58-0.73, I2 = 40%). However, there were no differences in the duration of stent patency or the incidence of adverse events (HR 1.04, 95% CI 0.84-1.29, I2 = 46%; OR 1.41, 95% CI 1.02-1.96, I2 = 29%).

CONCLUSIONS

ERFA has a significant survival benefit for MBO, but does not increase the risk of adverse events.

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.

Recent Updates on Local Ablative Therapy Combined with Chemotherapy for Extrahepatic Cholangiocarcinoma: Photodynamic Therapy and Radiofrequency Ablation

Although chemotherapy constitutes of the first-line standard therapy for unresectable extrahepatic cholangiocarcinoma, the treatment outcomes are unsatisfactory. In recent years, local ablative therapy, which is delivered to the cholangiocarcinoma lesion via the percutaneous or endoscopic approach, has garnered attention for the treatment of unresectable, extrahepatic cholangiocarcinoma. Local ablative therapy, such as photodynamic therapy and radiofrequency ablation, can achieve local tumor control. A synergistic effect may also be expected when local ablative therapy is combined with chemotherapy. However, it is a long way from being entrenched as an established therapeutic technique, and several unresolved problems persist, including the paucity of evidence comparing photodynamic therapy and radiofrequency ablation. Clinical application of photodynamic therapy and radiofrequency ablation requires sound comprehension and assimilation of the available evidence to truly benefit each individual patient. In this study, we reviewed the current status, issues, and future prospects of photodynamic therapy and radiofrequency ablation for extrahepatic cholangiocarcinoma, with a special focus on their combination with chemotherapy.

Efficacy and safety of percutaneous endobilliary radiofrequency ablation with a novel temperature-controlled catheter in malignant biliary strictures

Purpose

The purpose of this study is to evaluate the efficacy and safety of temperature-controlled endobilliary radio-frequency ablation (EB-RFA) followed by metal stent placement for nonresectable malignant biliary strictures.

Material and methods

From May 2017 to March 2021, 18 patients with malignant biliary obstruction who had undergone percutaneous EB-RFA and stent placement (n = 9) or stent placement only (n = 9) were included in this retrospective study. Outcomes were stent patency, technical and clinical success, overall survival, and 30-day complication rate. Kaplan-Meier and Cox regression analyses were performed to examine the relationship of EB-RFA with stent patency and overall survival.

Results

The clinical and technical success rate for each group was 100%. The median stent patency was 128 days (95% CI: 122.2-133.8) in the EB-RFA group and 86 days (95% CI: 1.2-170.7) in the control group. It was significantly longer in the study group (p = 0.012). The mean overall survival was 267.7 ± 68.5 days (95% CI: 133.3-402.2) in the study group and 239.6 ± 33.9 days (95% CI: 173.1-306.2) in the control group. Log-rank test showed there was not a statistically significant difference in overall survival rates (p = 0.302). There were no major complications and no statistically significant difference in cholangitis rates (p = 0.620).

Conclusions

Percutaneous temperature-controlled EB-RFA combined with biliary stent placement for malignant biliary obstruction can be safe and feasible, and effectively increase stent patency.

Role of ERCP in Malignant Hilar Biliary Obstruction

Malignant hilar biliary obstruction (MHO), an aggressive perihilar biliary obstruction caused by cholangiocarcinoma, gallbladder cancer, or other metastatic malignancies, has a poor prognosis. Surgical resection is the only curative treatment method for biliary malignancies. However, most of the patients with MHO cannot undergo surgeries on presentation because of an advanced inoperable state or a poor performance state due to old age or comorbid diseases. Therefore, palliative biliary drainage is mandatory to improve symptomatic jaundice and quality of life. Among drainage methods, endoscopic biliary drainage is the current standard for the palliation of unresectable advanced MHO. The development of stents and various accessories and advances in endoscopic techniques including endoscopic ultrasonography have facilitated primary endoscopic intervention in difficult high-grade hilar strictures. However, some issues are still under debate, such as palliation methods, appropriate stents, the number of stents, deployment methods, and additional local ablation therapies. Therefore, this review presents currently optimal endoscopic palliation methods for advanced MHO based on the reported literature.

Comparing palliative treatment options for cholangiocarcinoma: photodynamic therapy vs. radiofrequency ablation

Referral to an endoscopist is often done once curative resection is no longer an option for cholangiocarcinoma management. In such cases, palliation has become the main objective of the treatment. Photodynamic therapy and radiofrequency ablation can be performed to achieve palliation, with both procedures associated with improved stent patency and survival. Despite the greatly increased cost and association with photosensitivity, photodynamic therapy allows transmission to the entire biliary tree. In contrast, radiofrequency ablation is cheaper and faster to apply, but requires intraductal contact. This paper reviews both modalities and compares their efficacy and safety for bile duct cancer palliation.

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.

Comparison of Intraductal RFA Plus Stent versus Stent-Only Treatment for Unresectable Perihilar Cholangiocarcinoma—A Systematic Review and Meta-Analysis

Simple Summary

In patients with unresectable perihilar cholangiocarcinoma, adequate biliary drainage is essential. Stent patency remains a challenge in these complex patients, as both plastic and metal stent occlusion may occur, necessitating additional drainage procedures. Radiofrequency ablation (RFA) is a promising local treatment that has already proven its usefulness in other malignancies, such as hepatocellular carcinoma. In this meta-analysis and systematic review, we aimed to compare intraductal RFA with stent placement to stent placement alone in patients with unresectable perihilar cholangiocarcinoma. We found that RFA + stent treatment showed a significantly longer overall survival, in comparison to stent-only treatment. Further research is necessary in order to validate these findings to support the implementation of this promising strategy in clinical practice.

Abstract

Background: One of the cornerstones of palliative treatment for unresectable perihilar cholangiocarcinoma is biliary stent placement in order to restore biliary drainage. In this review, the potential added value of RFA with stent placement in comparison to stent placement alone in patients with unresectable perihilar cholangiocarcinoma is analyzed. Methods: We performed a comprehensive online search for relevant articles in November 2021 (PROSPERO ID: CRD42021288180). The primary endpoint was difference in overall survival. Secondary endpoints included overall survival, stent patency and complications. Only studies comparing survival after RFA + stent placement with stent placement alone were included in the meta-analysis. Non-comparative studies or comparative studies describing stent patency only were included in the systematic review. Results: A total of nine studies, including 217 patients with pCCA who underwent RFA + stent placement and 294 patients who underwent stent-only treatment, met the inclusion criteria for the primary endpoint analysis. Direct comparison between the two treatment groups showed a significantly longer overall survival for RFA + stent treatment, with a pooled HR of 0.65 [95% CI, 0.50–0.84, I² = 38%]. When all eligible studies were included, RFA + stent treatment revealed an overall survival of 9.5 months [95% CI, 6.3–12.6], whereas survival for stent-only treatment was 7.0 months [95% CI, 5.7–8.2]. Due to the heterogeneity of the data, no pooled data analysis could be performed on stent patency or complications. Conclusions: RFA + stent placement displays promising potential to prolong survival. However, further research incorporating confounding factors like use of palliative chemotherapy is necessary in order to validate these findings.

Local palliative therapies for unresectable malignant biliary obstruction: radiofrequency ablation combined with stent or biliary stent alone? An updated meta-analysis of nineteen trials

BACKGROUND

Recently, there has been a burgeoning interest in radiofrequency ablation combined with stent (RFA + Stent) for unresectable malignant biliary obstruction (MBO). This study aimed to perform a meta-analysis to evaluate the efficacy and safety of RFA + Stent compared with biliary stent alone.

METHODS

We searched PubMed, Cochrane Library, Embase, and Web of Science databases from their inception dates to June 20, 2021, for studies that compared RFA + Stent and stent alone for unresectable MBO. The main outcomes were survival, patency, and adverse effects. All meta-analyses were calculated using the random-effects model.

RESULTS

A total of 19 studies involving 1946 patients were included in this study. Compared with stent alone, RFA + Stent was significantly associated with better overall survival (HR 0.55; 95% CI 0.48, 0.63; P < 0.00001), longer mean survival time (SMD 2.20; 95% CI 1.17, 3.22; P < 0.0001), longer mean stent patency time (SMD 1.37; 95% CI 0.47, 2.26; P = 0.003), higher stent patency at 6 months (OR 2.82; 95% CI 1.54, 5.18; P = 0.0008). The two interventions had similar incidence of postoperative abdominal pain (OR 1.29; 95% CI 0.94, 1.78; P = 0.11), mild bleeding (OR 1.28; 95% CI 0.65, 2.54; P = 0.48), cholangitis (OR 1.09; 95% CI 0.76, 1.55; P = 0.65), pancreatitis (OR 1.39; 95% CI 0.82, 2.38; P = 0.22). Furthermore, the serum bilirubin levels and stricture diameter after operations were significantly alleviated than before operations, but the degree of alleviation between the two groups were not significantly different (all P > 0.05).

CONCLUSION

Although the alleviation of serum bilirubin and stricture diameter did not differ between the two interventions, RFA + Stent can significantly improve the survival and stent patency with comparable procedure-related adverse events than stent alone. Thus, RFA + Stent should be recommended as an attractive alternative to biliary stent alone for patients with unresectable MBO.

Endobiliary Radiofrequency Ablation for Malignant Biliary Obstruction over 32-Month Follow-Up

Hilar cholangiocellular carcinoma (CCC) is a malignant neoplasm of epithelial origin occurring at the confluence of the right and left hepatic bile ducts. Typically, these tumors are small, poorly differentiated, exhibit aggressive biologic behavior with non-specific symptoms and tend to obstruct the intrahepatic bile ducts. Surgery is the only available curative option. Unfortunately, in less than half of the patients a complete resection is possible with poor survival rate in unresectable cases. In this report, we present the case of a 58-year-old woman with a history of unresectable hilar cholangiocarcinoma. Initially she was treated with intraductal dilatation of malignancy and placement of a plastic stent and chemotherapy (Gemcitabin® and Platinol®). Two years later she underwent a second-line chemotherapy with Gemcitabin® and Oxyplatin® because of tumor progression. Despite a second line chemotherapy and placement of an uncovered self-expandible metal stent (ucSEMS) that was extended later on by stent-in stent technique, there was tumor progression which led to a complex course with relapsing obstructive cholangiosepsis and cholestasis. Because of tumor ingrowth, endobiliary radiofrequency ablation of the malignant stenosis was performed in repeated sessions. This case illustrates that radiofrequency ablation of solitary malignant biliary obstruction is feasible, safe and allows an improvement of quality of life in non-operable patients.

Photodynamic Therapy (PDT), Radiofrequency Ablation (RFA) With Biliary Stents in Palliative Treatment of Unresectable Extrahepatic Cholangiocarcinoma: A Systematic Review and Meta-analysis

BACKGROUND AND AIM

Extrahepatic unresectable cholangiocarcinoma carries a dismal prognosis. In addition to biliary drainage by stent placement; photodynamic therapy (PDT) and radiofrequency ablation (RFA) have been tried to prolong survival. In this meta-analysis, we appraise the current known data on the use of PDT, RFA in the palliative treatment of extrahepatic unresectable cholangiocarcinoma.

METHODS

We searched multiple databases from inception through July 2020 to identify studies that reported on PDT and RFA. Pooled rates of survival, stent patency, 30-, 90-day mortality, and adverse events were calculated. Study heterogeneity was assessed using I2% and 95% prediction interval.

RESULTS

A total of 55 studies (2146 patients) were included. A total of 1149 patients underwent treatment with PDT (33 studies), 545 with RFA (22 studies), and 452 patients with stent-only strategy. The pooled survival rate with PDT, RFA, and stent-only groups was 11.9 [95% confidence interval (CI): 10.7-13.1] months, 8.1 (95% CI: 6.4-9.9) months, and 6.7 (95% CI: 4.9-8.4) months, respectively. The pooled time of stent patency with PDT, RFA, and stent-only groups was 6.1 (95% CI: 4.2-8) months, 5.5 (95% CI: 4.2-6.7) months, and 4.7 (95% CI: 2.6-6.7) months, respectively. The pooled rate of 30-day mortality with PDT was 3.3% (95% CI: 1.6%-6.7%), with RFA was 7% (95% CI: 4.1%-11.7%) and with stent-only was 4.9% (95% CI: 1.7%-13.1%). The pooled rate of 90-day mortality with PDT was 10.4% (95% CI: 5.4%-19.2%) and with RFA was 16.3% (95% CI: 8.7%-28.6%).

CONCLUSION

PDT seemed to demonstrate better overall survival and 30-day mortality rates than RFA and/or stent-only palliation.

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.

Efficacy and safety of temperature-controlled intraductal radiofrequency ablation in advanced malignant hilar biliary obstruction: A pilot multicenter randomized comparative trial

PURPOSE

We aimed to evaluate the efficacy and safety of temperature-controlled intraductal radiofrequency ablation (ID-RFA) for advanced malignant hilar biliary obstruction (MHBO).

METHODS

Patients were randomly assigned to RFA group (ID-RFA and bilateral plastic stent [PS]) or non-RFA group (bilateral PS) at a 1:1 ratio. Exchange to self-expanding metal stent (SEMS) was performed after 3 months or when premature PS occlusion occurred. Total event-free stent patency, overall survival (OS), and adverse events (AEs) were analyzed.

RESULTS

A total of 30 patients from three hospitals were enrolled. Stent patency and OS did not differ between the two groups (178 days vs 122 days, P = .154; 230 days vs 144 days, P = .643; respectively). In patients with each stricture length ≥11 mm on both sides, stent patency was longer in the RFA group than in the non-RFA group (175 days vs 121 days, P = .028). More patients received elective exchange to SEMS without PS occlusion in the RFA group than in the non-RFA group (69.2% vs 23.1%, P = .018). AE rates did not differ between the two groups.

CONCLUSIONS

Temperature-controlled ID-RFA for advanced MHBO was safe and feasible. It could prevent premature PS occlusion within 3 months.

[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.

[A Recent Update on Endoscopic Drainage of Advanced Malignant Hilar Obstruction]

Malignant hilar obstruction (MHO) is considered an aggressive perihilar obstruction caused by cholangiocarcinoma, gallbladder cancer, or metastatic malignancies and has a poor prognosis. Although surgical resection is the only curative treatment method, the majority of patients with MHO do not undergo surgery due to an advanced inoperable state at presentation. Currently, effective biliary drainage provides the necessary palliation for symptomatic improvement. Among the drainage methods, percutaneous access may be preferred, especially for advanced MHO because of the technical difficulty involved with other techniques. Recently, primary endoscopic palliation using plastic or metal stents has been shown to have higher technical feasibility and clinical success without increasing adverse events even in patients with high-degree MHO. The development of various accessories, endoscopic ultrasonography, and advances in techniques have facilitated primary endoscopic intervention. However, some aspects continue to be debated such as the palliation methods, appropriate stents, the number of stents, the deployment methods, and additional local ablation therapies. Therefore, this review discusses the current optimal endoscopic treatment methods for advanced MHO based on reported literature.

Interventional Treatment for Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common type of primary liver malignancy. The latest classification includes intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma, with the latter one further categorized into perihilar and distal cholangiocarcinoma. Although surgical resection is the preferred treatment for CCA, less than half of the patients are actually eligible for radical surgical resection. Interventional treatment, such as intra-arterial therapies, ablation, and brachytherapy (iodine-125 seed implantation), has become an acceptable palliative treatment for patients with unresectable CCA. For these patients, interventional treatment is helpful for locoregional control, symptom relief, and improving quality of life. Herein, in a timely and topical manner, we will review these advances and highlight future directions of research in this article.

Feasibility and Safety of Endoluminal Radiofrequency Ablation as a Rescue Treatment for Bilateral Metal Stent Obstruction Due to Tumor Ingrowth in the Hilum: A Pilot Study

Background. Radiofrequency ablation (RFA) is a palliative method known for its application in the endoscopic treatment of malignant bile duct obstruction. It may be a useful rescue method for metal stent malfunction caused by tumor ingrowth. This study aimed to examine the feasibility and safety of endoluminal RFA for occluded bilateral hilar metal stents due to tumor ingrowth in patients with malignant hilar bile duct obstruction. Methods: From March 2016 to June 2018, 11 patients with unresectable malignant hilar bile duct stricture with occluded bilateral hilar metal stents due to tumor ingrowth were enrolled. Endoluminal RFA was performed through a novel temperature-controlled catheter at a setting of 7 W power for 120 s with a target temperature of 80 °C via endoscopic retrograde cholangiopancreatography (ERCP). The patients’ demographics, clinical outcomes, and adverse events were investigated. Results: The median age was 64 (interquartile range, 54–72) years. All RFA procedures were successful. Clinical success was achieved in eight patients (72.7%). During the follow-up, eight patients (72.7%) showed stent dysfunction, and the median patency after RFA was 50 days (95% confidence interval (CI): 34–not available (NA)). All stent dysfunctions were successfully managed with ERCP. Ten patients died, and the median overall survival was 289 days (95% CI, 107–NA) from RFA to death. There was one case of mild abdominal pain after the procedure without serious adverse events. Conclusions: As a rescue therapy for occluded bilateral hilar metal stents due to tumor ingrowth, endoluminal RFA seemed to be safe and useful in selected patients.

Survival Benefit of Intraductal Radiofrequency Ablation for Malignant Biliary Obstruction: A Systematic Review with Meta-Analysis

BACKGROUND/AIMS

Cholangiocarcinoma (CCA) is a rare but aggressive disease with a poor survival. Recent trials have shown improved survival with intraductal radiofrequency ablation (RFA) therapy. We performed a systematic review with meta-analysis to determine the survival benefit of endoscopic RFA for unresectable extrahepatic CCA with malignant biliary obstruction (MBO).

METHODS

A systematic search from 1970 to 2020 was performed in MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials. gov. We selected eligible studies reporting relative risks, hazard ratios (HRs), or odds ratios, adjusted by controlling for confounding factors of survival rate and stent patency duration, among patients with extrahepatic CCA with MBO treated with RFA with stent insertion or stent insertion only.

RESULTS

A total of eight trials (three randomized and five nonrandomized) with a total of 420 patients were included in the metaanalysis. Pooled overall survival analysis favored RFA treatment with stent insertion (HR, 0.47; 95% confidence interval [CI], 0.34- 0.64; I2=47%; p=0.09); however, no significant difference was found in the duration of stent patency between the groups (HR, 0.79; 95% CI, 0.57-1.09; I2=7%; p=0.36).

CONCLUSION

RFA therapy with stent insertion may confer a survival benefit compared with stent insertion only in patients with CCA and MBO.

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 radiofrequency ablation in patients with unresectable malignant biliary strictures

INTRODUCTION

previous studies have shown that endoscopic radiofrequency ablation in unresectable biliary duct tumors prolongs survival.

METHODS

this was an observational study of patients with an unresectable malignant stricture. The aim was to evaluate survival, stent patency and adverse events of radiofrequency compared with a matched control group.

RESULTS

the study included 40 patients, 12 with radiofrequency. There were no differences between baseline parameters in both groups. The survival time was longer in the radiofrequency group with no statistically significant difference (217 vs 129 days, log-rank 0.31). There was no difference in stent permeability or adverse events.

CONCLUSION

the radiofrequency group had a three-month increase in survival, which did not reach statistical significance.

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.

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.

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.

Intraductal temperature-controlled radiofrequency ablation in malignant hilar obstruction: a preliminary study in animals and initial human experience

Background and study aims  Intraductal radiofrequency ablation (ID-RFA) is a recently developed method widely used for treatment of malignant extrahepatic biliary tract obstructions. However, its safety in hilar application has yet to be clearly demonstrated. The aim of this study was to evaluate the safety of ID-RFA in the treatment of malignant hilar obstruction. Patients and methods  Endoscopic retrograde cholangiography followed by temperature-controlled ID-RFA at the hilar area using different probe lengths (11, 18, and 22 mm) and settings (7 or 10 W for 60 - 120 s) was performed in six mini-pigs. In addition, patients with malignant hilar obstruction who underwent palliative ID-RFA were retrospectively evaluated. Results  In the animal study using different ID-RFA settings , post-ID-RFA fluoroscopic radiocontrast leakage and microscopic bile duct perforation with hepatic abscess were observed in four of the six mini-pigs. Only two of the them, in which an 11-mm ID-RFA probe at a target temperature of 80 °C, power of 7 W, and duration of 60 s was used, underwent successful ID-RFA without any immediate adverse events (AEs). Clinically, ID-RFA was performed using the 11-mm probe with the setting of 80 °C, 7 W, and 60 - 120 s for malignant hilar obstruction, and total of 11 patients underwent successful ID-RFA without AEs. Conclusions  Our study suggests that ID-RFA performed using a short-length probe with settings of 80 °C, 7 W and 60 - 120 s is a safe and feasible palliative treatment for malignant hilar obstruction.

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.

The safety of newly developed automatic temperature-controlled endobiliary radiofrequency ablation system for malignant biliary strictures: A prospective multicenter study

BACKGROUND AND AIMS

Catheter-based endobiliary radiofrequency ablation (RFA) is an endoscopic local treatment for patients with malignant biliary stricture (MBS). However, excessive heating of the bile duct by the current RFA system can induce serious complications. Recently, a new RFA system with automatic temperature control was developed. In the present study, we examined the safety of the new RFA system in patients undergoing endobiliary RFA for extrahepatic MBS.

METHODS

This prospective, multicenter study enrolled patients with unresectable or inoperable extrahepatic (> 2 cm from the hilum) MBS. Endobiliary RFA was performed using a newly developed RFA catheter (ELRA™, STARmed, Goyang, Korea) at a setting of 7 or 10 W for 120 s and with a target temperature of 80°C. A self-expandable metallic stent was inserted after endobiliary RFA. The rate of procedure-related adverse events was assessed.

RESULTS

The 30 patients were enrolled in this study. Cholangiocarcinoma was diagnosed in 19 patients, pancreatic cancer was found in 9, and gallbladder cancers were recorded in 2. The mean stricture length was 22.1 ± 6.6 mm. Post-procedural adverse events occurred in three patients (10.0%; 2 mild pancreatitis and 1 cholangitis) without hemobilia and bile duct perforation. The pancreatitis and cholangitis resolved with conservative treatment. The cumulative duration of stent patency and survival were 236 and 383 days, respectively.

CONCLUSIONS

Automatic temperature-controlled endobiliary RFA using a newly developed catheter was safely applied in patents with extrahepatic MBS. Further prospective studies are needed to confirm the efficacy of endobiliary RFA for MBS.

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.

Endoscopic Retrograde Cholangiopancreatography-Guided Ablation for Cholangiocarcinoma

Most patients with perihilar cholangiocarcinoma present with surgically unresectable disease owing to the insidious nature of this malignancy. Relief of malignant perihilar biliary obstruction is a key aspect of cholangiocarcinoma. Although palliative stenting using uncovered metal stents has been advocated in patients with unresectable malignant perihilar biliary strictures, several endoscopic retrograde cholangiopancreatography-guided ablative modalities have emerged. Palliative photodynamic therapy, radiofrequency ablation, and intraluminal brachytherapy have been associated with improved stent patency and survival, although the ideal treatment approach remains unclear. This article reviews the published evidence for using each of these endobiliary ablative modalities in this difficult-to-treat patient population.