Safety and efficacy of radiofrequency ablation in the management of unresectable bile duct and pancreatic cancer: a novel palliation technique

Radiofrequency ablation for pancreatobiliary disease: an updated review

Endoscopic radiofrequency ablation (RFA) has emerged as a minimally invasive treatment option in cases of malignant biliary obstruction, pancreatic cancer, and other pancreatic cystic neoplasms. Intraductal biliary RFA is safe, effective, and confers a survival advantage over stenting alone, where it should be used an adjunct to biliary stenting. Endoscopic ultrasound-guided RFA can also provide pancreatic cyst resolution in patients who are not ideal operative candidates. The aim of this review is to describe the endoscopic applications and associated outcomes of RFA.

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.

Double bare metal stent deployment combined with intraductal radiofrequency ablation for malignant distal biliary obstruction: a prospective pilot study

Although uncovered self-expandable metal stents (SEMSs) possess certain advantages such as averting cystic duct obstruction and stent migration, they are susceptible to ingrowth occlusion. The combination of the double bare stent (DBS) and endobiliary radiofrequency ablation (RFA) may reduce ingrowth. Hence, this study aimed to examine the utility of this method for the treatment of unresectable malignant distal biliary obstruction (MDBO). This prospective, single-center, pilot study enrolled 51 patients who met the eligibility criteria between February 2020 and January 2022. The study outcomes included technical success, clinical success, recurrent biliary obstruction (RBO), and other adverse events (AE) besides RBO associated with DBS placement with RFA for MDBO. The technical success rate was 98.0% (50/51). Clinical success was achieved in all patients in whom technical success was achieved. The rates of early and late AEs were 5.9% (3/51) and 8.0% (4/50), respectively. The incidence rate of RBO was 38.0% (19/50). Sludge occlusion, ingrowth occlusion, and overgrowth occlusion occurred in 26.0% (13/50), 8.0% (4/50), and 2.0% (1/50) of patients, respectively (the main cause of RBO was undeterminable in 1 patient). The median time to RBO was 241 days. DBS with RFA showed good technical feasibility, good long-term outcomes, acceptable AE rates, and most importantly, a low ingrowth occlusion rate when employed for the treatment of MDBO.

Endoscopic palliation of malignant biliary obstruction

Malignant biliary obstruction often presents with challenges requiring the endoscopist to assess the location of the lesion, the staging of the disease, the eventual resectability and patient preferences in term of biliary decompression. This review will focus on the different modalities available in order to offer the most appropriate palliation, such as conventional endoscopic retrograde cholangiopancreatography, endoscopic ultrasound guided biliary drainage as well as ablative therapies including photodynamic therapy or radiofrequency ablation.

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.

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.

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.

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.

[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.

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.

The combination of endoluminal radiofrequency ablation and metal stent implantation for the treatment of malignant biliary stenosis - Randomized study

PURPOSE

To analyse whether endobiliary radiofrequency ablation prior metal stent insertion in malignant biliary stenosis show improved survival or stent patency.

METHODS

76 patients with histologically proven malignant biliary stenosis have been enrolled in a prospective, randomized study. In control arm, 40 patients underwent self-expandable metal stent insertion. In experimental arm, the endoluminal ablation with a bipolar radiofrequency catheter was performed immediately before stent insertion. A subgroup analysis of cholangiocarcinoma was performed (22 vs 21 patients). The objective of the study was to determine the rate of complications, duration of the stent patency and the survival of patients (Kaplan-Meier analysis).

RESULTS

No major complications related to the stent insertion and the endoluminal ablation were found. The mean primary stent patency was 5.2 (95% CI 0.7-12.8) vs 4.8 months (95% CI 0.8-18.2) months (p = 0.79) in control and experimental group, respectively, in the subgroup analysis with cholangiocarcinoma 4.5 (95% CI 0.8-10.3) and 9.6 (95% CI 5.2-11.2) months (p = 0.029). The median survival since the insertion of the stent was 6.8 (95 %CI 3.0-10.6) vs 5.2 (95 %CI 2.4-7.9) months (p = 0.495) and since the initial drainage 9.8 (95 %CI 6.9-12.7) vs 9.1 (95 %CI 5.4-12.7) months (p = 0.720) in the control and experimental arm.

CONCLUSION

Endobiliary radiofrequency ablation prior metal stent insertion showed increased patency rate only in patients with cholangiocarcinoma, on the other hand, no improvement in survival was demonstrated in this randomized clinical study.

Role of radio-ablative technique for optimizing the survival of patients with locally advanced pancreatic adenocarcinoma (Review)

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common and frequently diagnosed malignant tumor of the pancreas with few treatment options and poor life expectancy. Despite the advances in the surgical field, 40% of the patients are diagnosed with locally advanced disease which is not suitable for surgery. Radio-frequency ablation (RFA) has been described as a new ‘weapon’ in the multimodal treatment of PDAC, representing a cytoreductive procedure which must be completed with radiotherapy or chemo-radiotherapy. A systematic research was carried out utilizing the PubMed database in regards to this subject, to evaluate the role of RFA in PDAC management. Abstracts, letters-to-the-editor and non-English language manuscripts were excluded. The literature showed that RFA can be used in open and laparoscopic surgery but it is also feasible for endoscopic ultrasound (EUS-guided RFA) or percutaneous approach. Even though we found optimistic and encouraging reports on overall survival (OS), randomized studies are still required to corroborate these findings. Our review research underline that surgical resection remains the only radical treatment option, RFA being a safe and feasible technique reserved for unresectable, non-metastatic pancreatic tumors. Its combination with oncological treatment can improve the OS of these patients.

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.

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.

Endoscopic palliation of biliary obstruction

Advanced pancreaticobiliary malignancy tends to be uncurable at presentation and causes significant morbidity for patients. Palliation for malignant biliary obstruction should be minimally invasive, cost-effective, and aim to improve quality of life of patients. Strategies of endoscopic palliation of malignant biliary obstruction can differ based on sites and degree of biliary obstruction with complex decisions of optimal stent type and placement that involve conscientious planning by a multidisciplinary team.

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.

Endoscopic Palliation for Biliary and Pancreatic Malignancies: Recent Advances

Malignancies of the pancreatobiliary system are usually unresectable at the time of diagnosis. As a consequence, a majority of these cases are candidates for palliative care. With advances in chemotherapeutic agents and multidisciplinary care, the survival rate in pancreatobiliary malignancies has improved. Therefore, there is a need to provide an effective and long-lasting palliative care for these patients. Endoscopic palliation is preferred to surgery as the former is associated with equal efficacy and reduced morbidity. The main role of endoscopic palliation in the vast majority of pancreatobiliary malignancies includes biliary and enteral stenting for malignant obstructive jaundice and gastric outlet obstruction, respectively. Recent advances in endoscopic palliation appear promising in imparting long-lasting relief of symptoms. Use of radiofrequency ablation and photodynamic therapy in malignant biliary obstruction has been shown to improve the survival rates as well as the patency of biliary stents. The emergence of endoscopic ultrasound (EUS) as a therapeutic tool has enhanced the capability of minimally invasive palliation in pancreatobiliary cancers. EUS is a valuable alternative to endoscopic retrograde cholangiopancreatography for the palliation of obstructive jaundice. More recently, EUS is emerging as an effective primary modality for biliary and gastric bypass.

Unexpected outcome following radiofrequency ablation of a malignant biliary stricture

We present a case of a 60-year-old woman with extrahepatic cholangiocarcinoma and recurrent malignant biliary strictures status post placement of two overlapping distal bile duct uncovered self-expandable metal stents (SEMSs) who presented with biliary obstruction due to tumor/tissue ingrowth. She subsequently underwent radiofrequency ablation (RFA) through SEMS to improve biliary stent patency. Post-RFA, thermal injury was observed in the periampullary mucosa. She later developed acute pancreatitis. This is the first case of RFA-induced acute pancreatitis with endoscopic evidence of thermal injury. It should be noted that RFA-induced acute pancreatitis is a potential adverse effect as RFA through SEMS is being used more widely.

Radiofrequency assisted pancreaticoduodenectomy for palliative surgical resection of locally advanced pancreatic adenocarcinoma

Background

Despite careful patient selection and preoperative investigations curative resection rate (R0) in pancreaticoduodenectomy ranges from 15% to 87%. Here we describe a new palliative approach for pancreaticoduodenectomy using a radiofrequency energy device to ablate tumor in situ in patients undergoing R1/R2 resections for locally advanced pancreatic ductal adenocarcinoma where vascular reconstruction was not feasible.

Results

There was neither postoperative mortality nor significant morbidity. Each time the ablation lasted less than 15 minutes. Following radiofrequency ablation it was observed that the tumor remnant attached to the vessel had shrunk significantly. In four patients this allowed easier separation and dissection of the ablated tumor from the adherent vessel leading to R1 resection. In the other two patients, the ablated tumor did not separate from vessel due to true tumor invasion and patients had an R2 resection. The ablated remnant part of the tumor was left in situ.

Conclusion

Whenever pancreaticoduodenectomy with R0 resection cannot be achieved, this new palliative procedure could be considered in order to facilitate resection and enable maximum destruction in remnant tumors.

Method

Six patients with suspected tumor infiltration and where vascular reconstruction was not warranted underwent radiofrequency-assisted pancreaticoduodenectomy for locally advanced pancreatic ductal adenocarcinoma. Radiofrequency was applied across the tumor vertically 5–10 mm from the edge of the mesenteric and portal veins. Following ablation, the duodenum and the head of pancreas were removed after knife excision along the ablated line. The remaining ablated tissue was left in situ attached to the vessel.

Irreversible electroporation of locally advanced solid pseudopapillary carcinoma of the pancreas: A case report

Introduction

Solid pseudopapillary Carcinoma (SPC) is a rare pancreatic Tumor with variable, usually low, malignancy potential. Howewer, several SPC are associated with aggressive behavior, local vascular infiltration, organ invasion, distant metastasis, and can be unresectable. Irreversible Electroporation (IRE) is an emerging non-thermal ablation technique for the treatment of locally advanced pancreatic carcinoma. We report the results of four year disease-free follow-up in a case of locally advanced unresectable SPC treated with IRE.

Presentation of case

A 24-year female patient with SPC of the pancreas underwent IRE during laparotomy under general anesthesia with intubation. Computed Tomography (CT) showed complete tumor thrombosis of splenic vein, encasement of celiac artery and mesenteric vein. Six insertions of 3–4 electrodes per insertion were performed. One month-CT-control showed shrinkage of the tumor. 6 months-post-treatment imaging showed complete regression of the mass, patent Splenic/mesenteric veins, absence of local recurrence or distant metastasis. Post treatment CTs at 12-18-24-30-36-42-48 months follow-up confirmed absence of local or distant recurrence.

Discussion

Surgery is the first choice curative treatment of SPC. Howewer aggressive surgery (duodeno-pancreasectomy) in unresectable cases, may have a high risk of recurrences, morbidities and death, and bring concerns about endocrine and exocrine insufficiency in a young patient. In these cases, IRE could be a safe and effective alternative treatment and could realize, in selected cases, the condition for a radical surgery, and a bridge to R-0 resection.

Conclusions

IRE could represent an effective alternative therapy to surgery in local advanced, unresectable SPC.

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Solid pseudopapillary Carcinoma (SPC) is a rare pancreatic Tumor with possible local vascular infiltration, distant metastasis, and can be unresectable.

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Irreversible Electroporation (IRE) is a non-thermal ablation technique for locally advanced pancreatic neoplasms.

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There is no case of SPC treated with IRE reported in the literature.

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IRE could be a safe and effective alternative treatment and could be a bridge to R-0 resection.

Percutaneous intraductal radiofrequency ablation in the management of unresectable Bismuth types III and IV hilar cholangiocarcinoma

Purpose

To assess the feasibility and safety of percutaneous intraductal radiofrequency ablation (RFA) for unresectable Bismuth types III and IV hilar cholangiocarcinoma.

Results

Percutaneous intraductal RFA combined with metal stent placement was successful in all patients without any technical problems; the technical success rate was 100%. Chemotherapy was administered to two patients. After treatment, serum direct bilirubin levels were notably decreased. Six patients died during the follow-up period. Median stent patency from the time of the first RFA and survival from the time of diagnosis were 100 days (95% confidence interval (CI), 85–115 days) and 5.3 months (95% CI, 2.5–8.1 months), respectively. No acute pancreatitis, bile duct bleeding and perforation, bile leakage, or other severe complications occurred. Four cases of procedure-related cholangitis, three cases of postoperative abdominal pain, and five cases of asymptomatic transient increase in serum amylase were observed. One patient who presented with stent blockage 252 days' post-procedure underwent repeat ablation.

Materials and Methods

Between September 2013 and May 2015, nine patients with unresectable Bismuth types III and IV hilar cholangiocarcinoma who were treated with percutaneous intraductal RFA combined with metal stent placement after the percutaneous transhepatic cholangial drainage were included in the retrospective analysis. Procedure-related complications, stent patency, and survival after treatment were investigated.

Conclusion

Percutaneous intraductal RFA combined with metal stent placement is a technically safe and feasible therapeutic option for the palliative treatment of unresectable Bismuth types III and IV hilar cholangiocarcinoma. Its long-term efficacy and safety is promising, but needs further study via randomized and prospective trials that include a greater number of patients.

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 ultrasound-guided radiofrequency ablation in gastroenterology: New horizons in search

Radiofrequency ablation (RFA) has been widely used for the treatment of various solid organ malignancies. Over the last decade, endosonographers have gradually shifted the application of RFA from porcine models to humans to treat a spectrum of diseases. RFA is performed in patients with pancreatic carcinoma who are not candidates for surgery. In this paper, we will discuss various indications for RFA, its procedural details and complications. At present, endoscopic ultrasound-guided RFA is gradually incorporated into the management of various diseases and opens a new avenue for disease treatment.

Successful endoscopic treatment of an intraductal papillary neoplasm of the bile duct

We present a case of a 76-year-old man with right upper quadrant abdominal pain and weight loss, who was found to have an intraductal papillary neoplasm of the bile duct (IPNB) of the pancreaticobiliary subtype, deemed curatively resectable. The patient declined surgery and opted for endoscopic therapy. He underwent two sessions of endoscopic retrograde cholangiopancreatography (ERCP)-guided radiofrequency ablation (RFA). Ten months later, no evidence of recurrence was identified on repeat ERCP. To our knowledge, this is the first reported case of successful use of RFA as a primary treatment modality for resectable IPNB.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

The safety and efficacy of percutaneous intraductal radiofrequency ablation in unresectable malignant biliary obstruction: A single-institution experience

Background

Patients with unresectable malignant biliary obstruction have limited life expectancy because of limited stent patency and tumor progression. The aim of our study was to retrospectively evaluate the safety and efficacy of combining intraductal RFA with biliary metal stent placement for patients with malignant biliary obstruction.

Methods

Patients who received percutaneous intraductal RFA and biliary stent placement for malignant biliary obstruction between 2013 and 2015 were identified. Outcomes were stent patency, technique and clinical success rate, overall survival (OS) and complication rates. Kaplan-Meier and Cox regression analyses were used to examine the association of various factors with stent patency and OS. Complications and laboratory abnormalities were recorded.

Results

Fifty patients were treated with percutaneous RFA and stent placement. The rates of technical success and clinical success were 98% and 92%, respectively. The median stent patency was 7.0 (95% confidence interval [CI]: 5.3, 8.7) months and OS was 5.0 (95% CI: 4.0, 6.0) months. On univariable analysis, previously cholangitis was an independent poor prognosis factor for recurrent biliary obstruction. OS was improved in patients who received more than one intervention compared to those who received only one intervention (log-rank P = 0.007), and in those treated without versus those treated with sequential chemotherapy (log-rank P = 0.017). On multivariable analysis, the occurrence of more than one intervention (P = 0.019) had independent prognostic significance for OS.

Conclusion

Percutaneous RFA and stent placement is a technically safe and feasible therapeutic option for the palliative treatment of malignant biliary obstruction. The long-term efficacy and safety of the procedure is promising, but further study is required via randomized and prospective trials.

Comparison of intraluminal radiofrequency ablation and stents vs. stents alone in the management of malignant biliary obstruction

PURPOSE

To retrospectively evaluate the added benefit of adding intraluminal radiofrequency ablation (RFA) to biliary metal stent placement for patients with malignant biliary obstruction (MBO).

METHODS

From November 2013 to December 2015, 89 patients with MBO who had undergone percutaneous intraluminal RFA and stent placement (RFA-stent group, n = 50) or stent placement only (stent group, n = 39) were included. Outcomes were compared according to the type of tumour: cholangiocarcinoma or non-cholangiocarcinoma.

RESULTS

Primary and secondary stent patency (PSP, SSP) were significantly higher for the RFA-stent group than the stent group (PSP: 7.0 months vs. 5.0 months, p = 0.006; SSP: 10.0 months vs. 5.6 months, p < 0.001), with overall survival being comparable (5.0 months vs. 4.7 months, p = 0.068). In subgroup analysis, RFA-stent showed significant PSP benefits compared to stent alone in patients with cholangiocarcinoma (7.4 months vs. 4.3 months; p = 0.009), but with comparable outcomes in patients with non-cholangiocarcinoma (6.3 months vs. 5.2 months; p = 0.266). The SSP was improved in both subgroups (cholangiocarcinoma, 12.6 months vs. 5.0 months, p < 0.001; non-cholangiocarcinoma, 10.3 months vs. 5.5 months, p = 0.013). Technical success and clinical success were not significantly different between the two groups. The rate of complication was higher for the RFA-stent group, but tolerable when compared to the stent group.

CONCLUSIONS

Although survival was comparable between the groups, RFA-stent confers therapeutic benefits to patients with MBO in terms of stent patency compared to stent placement alone, especially in those with cholangiocarcinoma.

Endoscopy-guided ablation of pancreatic lesions: Technical possibilities and clinical outlook

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP)-guided ablation procedures are emerging as a minimally invasive therapeutic alternative to radiological and surgical treatments for locally advanced pancreatic cancer (LAPC), pancreatic neuroendocrine tumours (PNETs), and pancreatic cystic lesions (PCLs). The advantages of treatment under endoscopic control are the real-time imaging guidance and the possibility to reach a deep target like the pancreas. Currently, radiofrequency probes specifically designed for ERCP or EUS ablation are available as well as hybrid cryotherm probe combining radiofrequency with cryotechnology. To date, many reports and case series have confirmed the safety and feasibility of that kind of ablation technique in the pancreatic setting. Moreover, EUS-guided fine-needle injection is emerging as a method to deliver ablative and anti-tumoral agents inside the tumuor. Ethanol injection has been proposed mostly for the treatment of PCLs and for symptomatic functioning PNETs, and the use of gemcitabine and paclitaxel is also interesting in this setting. EUS-guided injection of chemical or biological agents including mixed lymphocyte culture, oncolytic viruses, and immature dendritic cells has been investigated for the treatment of LAPC. Data on the long-term efficacy of these approaches, and large prospective randomized studies are needed to confirm the real clinical benefits of these techniques for the management of pancreatic lesions.

Safety and effectiveness of endobiliary radiofrequency ablation according to the different power and target temperature in a swine model

BACKGROUND AND AIM

Endobiliary radiofrequency ablation (EB-RFA) is a new endoscopic palliation and adjunctive tool. Although EB-RFA is performed worldwide, a possibility of iatrogenic thermal injury leading to perforation or bleeding still remains. Therefore, we aimed to assess the effects of thermal and coagulation injury after in vivo EB-RFA using a new catheter with a temperature sensor in a swine model.

METHODS

Twelve mini pigs were divided into four groups according to power (33 mm 10 W electrode vs. 18 mm 7 W electrode) and RFA target temperature (75°C vs. 80°C). All mini pigs underwent endoscopic retrograde cholangiography and target temperature controlled EB-RFA for 120 s. Additional cholangiogram was taken immediately after RFA, and all pigs were sacrificed after 24 h to assess the macroscopic/microscopic RFA injury.

RESULTS

Microscopic maximal injury depth and ablation area of EB-RFA using a 33-mm 10 W RFA electrode were significantly deeper and larger than those of EB-RFA using an 18-mm 7 W electrode (median; 2.7 vs. 2.1 mm, P = 0.004, 48.9 vs. 36.2 mm² , P = 0.016). However, there were no significant differences in microscopic ablation parameters between two different RFA target temperatures (75°C vs. 80°C). In addition, a post-RFA cholangiogram and assessment of the resected specimen at 24 h after the RFA showed no adverse events such as perforation or bleeding.

CONCLUSIONS

EB-RFA using a temperature controlled RFA catheter successfully ablates the bile duct wall without adverse events in a swine model.

Endoscopic radiofrequency ablation combined with fully covered self-expandable metal stent for inoperable periampullary carcinoma in a liver transplant patient: A case report

RATIONALE

Postliver transplant periampullary carcinoma is an extremely uncommon disease.

PATIENT CONCERNS

Cutaneous jaundice in a patient who had received a liver transplant 4 years earlier.

DIAGNOSIS

Periampullary carcinoma.

INTERVENTIONS

Radiofrequency ablation plus fully covered self-expanding metal stents (FCSEMS).

OUTCOMES

The treatment of malignant neoplasm of the ampulla of Vater is the patient by radiofrequency ablation plus FCSEMS placement was successful. No complications occurred.

LESSONS

This is the first reported case of a liver transplant patient with inoperable periampullary carcinoma successfully treated by radiofrequency ablation plus FCSEMS placement. Our experience will be useful to other surgeons in managing similar patients in the future.

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.

Percutaneous Intraductal Radiofrequency Ablation for Extrahepatic Distal Cholangiocarcinoma: A Method for Prolonging Stent Patency and Achieving Better Functional Status and Quality of Life

PURPOSE

The clinical efficacy of intraductal radiofrequency ablation (RFA) with Habib™ EndoHPB catheter, a newly developed intervention for malignant extrahepatic biliary obstruction, remains uncertain. The aim of this study was to investigate the clinical efficacy of intraductal RFA.

METHODS

Data from 71 patients with extrahepatic distal cholangiocarcinoma were retrospectively analyzed. The study patients were divided into RFA and control groups. The RFA group had undergone percutaneous transhepatic intraductal RFA with a Habib™ EndoHPB catheter, followed by placement of covered or uncovered biliary self-expandable metallic stents (SEMs) whereas the control group had undergone percutaneous transhepatic covered or uncovered SEMs placement. Procedure-related complications, stent patency, patient survival, and postoperative serum bilirubin concentrations were compared between the two groups. The Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) questionnaire was administered to evaluate functional status, improvement in clinical manifestations, and quality of life.

RESULTS

The RFA group had a longer median stent patency than the control group (p = 0.001 for uncovered SEMs placement). Higher functional well-being, hepatobiliary-specific cancer subscale, Trial Outcome Index, and total FACT-Hep scores were observed during post-procedure follow-up in the RFA group. However, median survival did not differ significantly between the two groups (p > 0.05).

CONCLUSIONS

Prolongation of stent patency and better functional status and quality of life, which are all important clinical endpoints, were observed in patients treated with intraductal RFA. Prospective randomized controlled clinical trials are necessary to further investigate the clinical efficacy and long-term benefits of intraductal RFA.

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.

The endoscopist's role in the diagnosis and management of pancreatic cancer

Pancreatic cancer remains one of the most lethal malignancies with little improvement in survival over the past several decades in spite of advances in imaging, risk factor identification, surgical technique and chemotherapy. This disappointing outcome is mainly due to failures to make an early diagnosis. In fact, the majority of the patients present with inoperable advanced stages of the disease. Though some of the new tumor markers are promising, we are still in search of the one that has a high sensitivity and accuracy, yet is inexpensive and easy to obtain. The paradigm of management has shifted from up-front surgery followed by adjuvant chemotherapy to neoadjuvant chemoradiation followed by surgery, especially for borderline resectable cancers and even for some resectable cancers. In this article, we will critically assess the limitations of tumor markers and review the advancements in endoscopic techniques in the management of pancreatic cancer.

Endoscopic versus Percutaneous Biliary Drainage in Palliation of Advanced Malignant Hilar Obstruction: A Meta-Analysis and Systematic Review

Background. Palliation in advanced unresectable hilar malignancies can be achieved by endoscopic (EBD) or percutaneous transhepatic biliary drainage (PTBD). It is unclear if one approach is superior to the other in this group of patients. Aims. Compare clinical outcomes of EBD versus PTBD. Methods. (i) Study Selection Criterion. Studies using PTBD and EBD for palliation of advanced unresectable hilar malignancies. (ii) Data Collection and Extraction. Articles were searched in Medline, PubMed, and Ovid journals. (iii) Statistical Method. Fixed and random effects models were used to calculate the pooled proportions. Results. Initial search identified 786 reference articles, in which 62 articles were selected and reviewed. Data was extracted from nine studies (N = 546) that met the inclusion criterion. The pooled odds ratio for successful biliary drainage in PTBD versus EBD was 2.53 (95% CI = 1.57 to 4.08). Odds ratio for overall adverse effects in PTBD versus EBD groups was 0.81 (95% CI = 0.52 to 1.26). Odds ratio for 30-day mortality rate in PTBD group versus EBD group was 0.84 (95% CI = 0.37 to 1.91). Conclusions. In patients with advanced unresectable hilar malignancies, palliation with PTBD seems to be superior to EBD. PTBD is comparable to EBD in regard to overall adverse effects and 30-day mortality.

Malignant biliary obstruction: From palliation to treatment

Malignant obstruction of the bile duct from cholangiocarcinoma, pancreatic adenocarcinoma, or other tumors is a common problem which may cause debilitating symptoms and increase the risk of subsequent surgery. The optimal treatment - including the decision whether to treat prior to resection - depends on the type of malignancy, as well as the stage of disease. Preoperative biliary drainage is generally discouraged due to the risk of infectious complications, though some situations may benefit. Patients who require neoadjuvant therapy will require decompression for the prolonged period until attempted surgical cure. For pancreatic cancer patients, self-expanding metallic stents are superior to plastic stents for achieving lasting decompression without stent occlusion. For cholangiocarcinoma patients, treatment with percutaneous methods or nasobiliary drainage may be superior to endoscopic stent placement, with less risk of infectious complications or failure. For patients of either malignancy who have advanced disease with palliative goals only, the choice of stent for endoscopic decompression depends on estimated survival, with plastic stents favored for survival of < 4 mo. New endoscopic techniques may actually extend stent patency and patient survival for these patients by achieving local control of the obstructing tumor. Both photodynamic therapy and radiofrequency ablation may play a role in extending survival of patients with malignant biliary obstruction.

Ablation Strategies for Locally Advanced Pancreatic Cancer

With the advent of novel and somewhat effective chemotherapy against pancreas cancer, several groups developed a new interest on locally advanced pancreatic cancer (LAPC). Unresectable tumors constitute up to 80% of pancreatic cancer (PC) at the time of diagnosis and are associated with a 5-year overall survival of less than 5%. To control those tumors locally, with perhaps improved patients survival, significant advances were made over the last 2 decades in the development of ablation methods including cryoablation, radiofrequency ablation, microwave ablation, high intensity focused ultrasound and irreversible electroporation (IRE). Many suggested a call for caution for possible severe or lethal complications in using such techniques on the pancreas. Most fears were on the heating or freezing of the pancreas, while non-thermal ablation (IRE) could offer safer approaches. The multimodal therapies along with high-resolution imaging guidance have created some enthusiasm toward ablation for LAPC. The impact of ablation techniques on primarily non-resectable PC remains, however, unclear.