Radiofrequency Ablation for Malignant Biliary Obstruction

Study Overview
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Brief Summary
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Biliary obstruction is importantly influencing quality of life and survival of patients suffering from primary or secondary bile duct malignancies. The aim of this retrospective data analysis is to evaluate endoscopic radiofrequency ablation (RFA) with the HabibTM EndoHBP catheter for the treatment of malignant biliary obstruction. RFA procedures performed in Austria so far will be analyzed with regard to feasibility and safety of the technique. Therefore, the following parameters will be assessed: (among others) technical failures during the RFA procedure, complications during the RFA procedure, hospital stay, adverse events during hospital stay and until first clinical control after discharge (an expected average of 4 weeks after RFA procedure), 30-day and 90-day mortality. The results of this study should help to better understand important aspects of biliary RFA which may positively influence future applications of this method.

Detailed Description
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Introduction Biliary obstruction is the most relevant life limiting factor in patients suffering from primary or secondary bile duct malignancies. Underlying tumors, such as extrahepatic cholangiocarcinoma (CCa) of Klatskin type, pancreatic adenocarcinoma or metastases of colorectal cancer, are often diagnosed at an advanced stage when presenting with biliary obstruction. This mostly restricts treatment strategies to palliative management. Within this setting the prevention of biliary complications like jaundice, cholangitis or cholangiosepsis is one of the therapeutic key factors to extend survival and maintain quality of life [De Groen, Skipworth]. Endoscopic stenting of the biliary tract is an easy and safe approach to restore biliary drainage [Smith]. Self-expanding metal stents are preferred to plastic stents because of the lower risk of stent occlusion [Kaassis, Soderlund]. In addition to stenting endoscopic therapies that directly affect the local tumor mass, have been developed within the past years. First of all, photodynamic therapy using different photosensitizers has shown promising results for the reduction of tumor size and maintenance of biliary drainage [Ortner, Zoepf]. However, the patient management for this treatment involving peri-interventional photosensitivity remains cumbersome. Recently, an endoscopically applicable radiofrequency catheter for the biliary tract, the so called HabibTM EndoHBP catheter, was introduced into the market. It uses bipolar electrical energy for tissue coagulation and can be applied without any special patient preparation in the context of an endoscopic retrograde cholangiopancreatography (ERCP) examination. RFA is well known from transcutaneous applications, where it already proved to be effective as a treatment option for hepatocellular carcinoma or intrahepatic CCa [Minami]. The new HabibTM EndoHBP catheter was already evaluated ex vivo [Itoi] and showed promising results concerning safety and prevention of stent occlusion in the context of one small retrospective clinical study [Steel]. Primary objective Feasibility and safety of endoscopic radiofrequency ablation with the HabibTM EndoHBP catheter for the treatment of malignant biliary obstruction Study Design Retrospective analysis of prospectively gained clinical data Primary endpoint Technical failures during the RFA procedure Secondary endpoints Complications during the RFA procedure Hospital stay Adverse events during hospital stay and unil first clinical control after discharge (an expected average of 4 weeks after RFA procedure) 30-day and 90-day mortality Study Population All patients who underwent endoscopic radiofrequency ablation with the HabibTM EndoHBP as a treatment for malignant biliary obstruction between November 2010 and December 2012 in Austria. Methods Endoscopic examination report databases will be screened for radiofrequency ablation in the context of an endoscopic retrograde cholangiopancreatography to identify the mentioned study population. Examination reports, discharge letters and patient curves of the study patients will be screened to yield the following parameters: Demographics Sex Age at first RFA-intervention Underlying disease that led to malignant biliary obstruction Type of underlying disease Time from diagnosis to first RFA-intervention Previous treatment attempts (chemotherapy, radiation therapy, photodynamic therapy) Procedure related parameters Prior biliary stents (type, amount) Date of RFA procedure Amount of RFA-applications during the procedure (energy, time) Technical failure of the RFA catheter during the RFA procedure (defined as any technical problem that hinders the satisfactory application of RFA) Complications during the RFA procedure (defined as any adverse change from the subject's baseline condition, i.e. any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease which is considered to be clinically relevant by the physician, whether or not considered related to the medical device) Stenting after the procedure (type, amount) Post-interventional parameters Days of hospitalization after the RFA procedure Adverse events during hospital stay and until first clinical control after discharge (an expected average of 4 weeks after RFA procedure) defined as any adverse change from the subject's baseline condition, i.e. any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease which is considered to be clinically relevant by the physician, whether or not considered related to the medical device Survial status (dead/alive) at the time of the data collection (Cause of death) (Time between first RFA procedure and death) Data processing will be done after pseudonymization using continuous patient identification numbers. All parameters will be assessed descriptively. For scaled parameters (e.g. age) median and range will be calculated, for nominal parameters (e.g. type of underlying disease) the proportions of sub-items will be reported. Mortality will be assessed creating a Kaplan Meyer curve. 30-day and 90-day mortality will be extrapolated from this curve. All data processing will be done with SPSS 19.0. Risk/Benefit assessment Due to its retrospective design this study does not inherit any risk for the study patients. Expected impact and Outlook The results of this study may help to better understand the feasibility and safety profile of endoscopic radiofrequency ablation with the HabibTM EndoHBP catheter with potential effects on future applications.

Official Title
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Endoscopic Radiofrequency Ablation for Malignant Biliary Obstruction

Conditions
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Biliary Tract Neoplasms

Intervention / Treatment
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* Procedure: Endoscopic radiofrequency ablation
* Procedure: Endoscopic retrograde cholangiopancreatography (ERCP)
* Device: HabibTM EndoHPB catheter


Participation Criteria
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Eligibility Criteria
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All patients who underwent endoscopic radiofrequency ablation with the HabibTM EndoHBP as a treatment for malignant biliary obstruction in Austria between November 2010 and December 2012.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Malignant biliary obstruction<br>All patients who underwent endoscopic radiofrequency ablation with the HabibTM EndoHBP as a treatment for malignant biliary obstruction in Austria between November 2010 and December 2012. | Procedure: Endoscopic radiofrequency ablation<br>* Endoscopic radiofrequency ablation with the HabibTM EndoHBP catheter uses bipolar electrical energy for tissue coagulation and can be applied without any special patient preparation in the context of an endoscopic retrograde cholangiopancreatography (ERCP) examination to treat malignant biliary strictures.<br>Procedure: Endoscopic retrograde cholangiopancreatography (ERCP)<br>* ERCP is used to guide the RFA-catheter under radiological control to the location of the malignant stricture.<br>Device: HabibTM EndoHPB catheter<br>* Used to apply radiofrequency energy to the malignant biliary stricture (see also intervention endoscopic radiofrequency ablation)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of RFA-procedures with technical failures | The technical feasibility in this study will be specified as ratio of all technically successful RFA-applications to all examinations in which RFA-use was intended. A RFA-application will be classified as technically successful if it is possible to introduce the RFA-catheter into the biliary system, place it adequately accross the malignant stricture, apply RFA-energy and withdraw the RFA-catheter after RFA-application. | During the respective RFA-examination (an expected average of 1 hour) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients with interventional complications | Clinically relevant complications occuring during the use of RFA, defined as any adverse change from the subject's baseline condition, which is considered to be clinically relevant by the physician, whether or not considered related to the medical device (e.g. bleeding, perforation). | During the respective RFA-procedure (an expected average of 1 hour) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Malignant biliary obstruction, Endoscopic radiofrequency ablation, Therapeutic endoscopy