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

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.

Endoscopic radiofrequency ablation for ingrowth occlusion after bilateral metal stent placement for malignant hilar biliary obstruction: a prospective pilot study

BACKGROUND AND AIMS

Endoscopic biliary radiofrequency ablation (RFA) may be an option for the treatment of ingrowth occlusion after self-expandable metal stent (SEMS) deployment; however, its utility remains uncertain. This study aimed to examine the feasibility of RFA for the palliation of ingrowth after bilateral SEMS placement in patients with malignant hilar biliary obstruction.

METHODS

This prospective, single-center, pilot study enrolled 30 patients who met the eligibility criteria between April 2020 and March 2022. Study outcomes were technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events (AEs) besides RBO associated with RFA for ingrowth occlusion. Furthermore, factors predictive of clinical success were evaluated.

RESULTS

Technical and clinical success rates were 93.3% (28/30) and 71.4% (20/28), respectively. The rates of early and late AEs were 6.7% (2/30) and 10.0% (2/20), respectively. The incidence rate of RBO after RFA was 45.0% (9/20), and the median time to RBO was 163 days. Multivariate analysis of the factors affecting clinical success revealed a positive association between the recanalization diameter on the ingrown part within the SEMS (odds ratio, 1.13; 95% confidence interval, 1.01-1.26; P = .038). The calculated optimal cutoff for the ratio of the recanalization diameter to the SEMS diameter for predicting clinical success was 51.1%.

CONCLUSIONS

Endoscopic biliary RFA elicited promising results, with good long-term stent patency and without the requirement of any additional stent placement, for the palliation of ingrowth occlusion after bilateral SEMS placement. However, the clinical success rate was insufficient, necessitating improvements in the future. (Clinical trial registration number: UMIN000040154.).

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.

Personalized Endoscopy in Complex Malignant Hilar Biliary Strictures

Malignant hilar biliary obstruction (HBO) represents a complex clinical condition in terms of diagnosis, surgical and medical treatment, endoscopic approach, and palliation. The main etiology of malignant HBO is hilar cholangiocarcinoma that is considered an aggressive biliary tract's cancer and has still today a poor prognosis. Endoscopy plays a crucial role in malignant HBO from the diagnosis to the palliation. This technique allows the collection of cytological or histological samples, direct visualization of the suspect malignant tissue, and an echoendoscopic evaluation of the primary tumor and its locoregional staging. Because obstructive jaundice is the most common clinical presentation of malignant HBO, endoscopic biliary drainage, when indicated, is the preferred treatment over the percutaneous approach. Several endoscopic techniques are today available for both the diagnosis and the treatment of biliary obstruction. The choice among them can differ for each clinical scenario. In fact, a personalized endoscopic approach is mandatory in order to perform the proper procedure in the singular patient.

Usefulness of intraductal RFA in patients with malignant biliary obstruction

BACKGROUND/AIMS

Intraductal radiofrequency ablation (ID-RFA) is a novel therapy for unresectable malignant biliary obstructions. ID-RFA for perihilar lesions is associated with a high risk of adverse events. We aimed to evaluate the feasibility and efficacy of temperature-controlled ID-RFA for perihilar malignant biliary obstruction.

METHODS

Sixteen patients with pathologically proven perihilar cholangiocarcinoma were prospectively enrolled to evaluate the feasibility of hilar ID-RFA. Clinical efficacy and outcomes were subsequently evaluated in a multicenter retrospective cohort.

RESULTS

Nine of the 16 patients in the prospective cohort had Bismuth type IV and 7 had type IIIA perihilar cholangiocarcinoma. The median length of stricture was 34.5 mm. The median number of ID-RFA sessions was three, and all sessions were technically and functionally successful without severe adverse events. Clinical outcomes were assessed using a multicenter hilar ID-RFA cohort of 21 patients; the median stent patency and overall survival were 90 days (range: 35-483 days) and 147 days (range: 92-487 days), respectively. An approximate 16-month patency of the bile duct was maintained in one patient who had an intraductal growth pattern. In a comparison of the self-expandable metallic stent (SEMS) and plastic stent (PS) after hilar ID-RFA, no differences in stent patency (89 vs 90.5 days, respectively; P = .912) and adverse events (20.0% vs 10%, respectively; P = .739) were observed.

CONCLUSIONS

ID-RFA at 7 W for 120 seconds is safe and feasible in patients with advanced perihilar cholangiocarcinoma. After ID-RFA, SEMS and PS placement showed comparable patency and survival rates.

TRIAL REGISTRATION NUMBER

KCT0003223.

New Devices for Endoscopic Treatments in Gastroenterology: A Narrative Review

Endoscopy is in a period of continuous innovations in terms of image quality, endoscopes, post-processing software and lastly, application of Artificial Intelligence. Therapeutic boundaries have expanded, widening the grey zone between endoscopy and surgery, and increasing endoscopic approaches in clinical scenarios where, until a few years ago, surgery was the only option. New scopes and accessories have made it easier to access critical areas such as the biliary tree and the small bowel intestine. In the field of hepato-pancreato-biliary endoscopy (HPB), it is now possible to directly access the biliary ducts or cystic lesions though dedicated stents and scopes, rather than having to rely only on fluoroscopy and ultrasound, increasing the diagnostic and therapeutic options by applying a three-dimensional approach. This narrative review will give an overview of some of the most relevant emerging fields in luminal and HPB endoscopy, highlighting advantages and main limitations of the techniques, and providing considerations for future development.

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.

Novel swine biliary dilatation model with temperature-controlled endobiliary radiofrequency ablation: An effective tool for training in EUS-guided biliary drainage

Background and Objectives:

EUS-guided biliary drainage (EUS-BD) is used as a rescue method after failed endoscopic retrograde cholangiography. However, it is considered a technically challenging procedure. Phantoms and ex vivo biliary dilatation models have been used to enhance the learning of EUS-BD, but they provide a limited level of realism. The aim of this study was to develop a swine biliary dilatation model that uses temperature-controlled endobiliary radiofrequency ablation (EB-RFA) for training in EUS-BD.

Materials and Methods:

Target temperature-controlled (80°C at 7 or 10 W for 60–120 s) EB-RFA was performed on seven pigs. Two weeks after the EB-RFA, EUS examination was performed to confirm biliary dilatation, and EUS-BD was then attempted by performing a hepaticogastrostomy (HGS) or cholecystogastrostomy (CGS).

Results:

Twelve sessions of EB-RFA (11 at the distal common bile duct [CBD] and one at the proximal CBD) were successfully performed on the seven pigs. There were no immediate postprocedural adverse events. Two weeks after the procedures, clinical signs of jaundice were observed in all the pigs. EUS examination revealed massive intrahepatic and extrahepatic biliary dilatations in all the pigs, and EUS-BD was attempted in the same session. HGS was performed on six pigs. Technical success was achieved in five of the six pigs (83.3%). Technical failure in HGS occurred during the stent deployment, and CGS was successfully performed on one pig.

Conclusions:

Our study shows that EB-RFA is an effective minimally invasive method for creating biliary dilatation models. It may be considered suitable for training in EUS-BD.

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.