Endoscopic Biliary Radiofrequency Ablation of Malignant Distal Common Bile Duct Strictures

A Randomized Controlled Trial of Endoscopic Biliary Radiofrequency Ablation of Malignant Distal Common Bile Duct Strictures.

Malignant bile duct obstruction is a common sequela of pancreatic cancers or distal bile duct cancers, and its development can hinder the use of chemotherapy, decrease patient quality of life, and decrease survival. To relieve obstructive jaundice as a result of the obstruction, endoscopic stent placement is usually required. The use self-expandable metal stents (SEMSs) have been shown to result in a longer patency times as compared with plastic stents. However, despite improvements in materials and stent design, stent obstruction still occurs in 13% to 44% of the patients. Tumor in-growth is the most common mechanism of stent obstruction. Recently, the use of endoscopic biliary radiofrequency ablation (EBRFA) have been described in patients suffering from inoperable malignant distal common bile duct (CBD) obstruction. The procedure uses heat energy to cause local tumour tissue death, resulting in re-opening of the bile duct lumen. The procedure has the potential of reducing the rate of stent obstruction after SEMS and also prolonging survival. The safety profile appears to be comparable that of placement of SEMS alone without added complications (<10%). The aim of the current study is to compare the efficacy of EBRFA with the addition of SEMS to SEMS alone in a randomized controlled trial.We hypothesize that the application of EBRFA can reduce recurrent biliary obstruction after SEMS.

Endoscopic retrograde cholangiopancreatography (ERCP) would be performed under standard operating conditions to confirm the length of the biliary stricture, diameter, and position. An uncovered self expanding metallic stent (SEMS) would be inserted to bypass the site of narrowing (Niti-S biliary uncovered metallic stent; Taewoong Medical, Gimpo City, Korea)

Endoscopic retrograde cholangiopancreatography (ERCP) would be performed under standard operating conditions to confirm the length of the biliary stricture, diameter, and position. The radiofrequency ablation (EBRFA) catheter would be placed under fluoroscopic guidance across the biliary stricture. The Habib EndoHPB (EMcision UK, London, United Kingdom) radiofrequency ablation catheter with energy delivered by an RFA generator would be used to apply RFA to the entire length of the stricture, sequential applications would be applied to complete treatment throughout the length of the stricture without significant overlap of treated areas. Patients would undergo 2 sessions of EBRFA 2 weeks apart. A plastic stent would be inserted in between the 2 sessions. An uncovered SEMSs (Niti-S biliary uncovered metallic stent; Taewoong Medical, Gimpo City, Korea) would be placed after the second EBRFA.

The radiofrequency ablation (RFA) catheter would be placed under fluoroscopic guidance across the biliary stricture. The Habib EndoHPB (EMcision UK, London, United Kingdom) radiofrequency ablation catheter is a bipolar RFA probe that is 8F (2.6 mm), 1.8 m long, compatible with standard (3.2-mm working channel) side-viewing endoscopes, and passes over 0.035-inch guidewires. The catheter has 2 ring electrodes 8 mm apart with the distal electrode 5 mm from the leading edge, providing local coagulative necrosis over a 2.5-cm length. Depending on the length of the stricture, sequential applications would be applied to complete treatment throughout the length of the stricture without significant overlap of treated areas. An uncovered SEMSs (Niti-S biliary uncovered metallic stent; Taewoong Medical, Gimpo City, Korea) would be placed after 2 sessions of EBRFA.

Inclusion Criteria: Age ≥ 18 years old with informed consent Histologically (preferred) or radiologically confirmed distal malignant bile duct tumors Inoperability by staging, comorbidities or patient wishes Distal tumors 2cm away from the portal hilum Bilirubin > 50umol/L at diagnosis Exclusion Criteria: Periampullary tumours Multiple hepatic metastases with significant blockage of one or more liver segments (if no segment blockage, metastasis is not an exclusion criteria) Presence of main portal vein thrombosis Prior SEMS placement Prior Billroth II or roux-en Y reconstruction History of bleeding disorder or use of anticoagulation Child's B/C cirrhosis Pregnancy Performance status ECOG ≥3 (confined to bed / chair > 50% waking hours) Presence of other malignancy Presence of gastric outlet obstruction Life expectancy < 3months

Steel AW, Postgate AJ, Khorsandi S, Nicholls J, Jiao L, Vlavianos P, Habib N, Westaby D. Endoscopically applied radiofrequency ablation appears to be safe in the treatment of malignant biliary obstruction. Gastrointest Endosc. 2011 Jan;73(1):149-53. doi: 10.1016/j.gie.2010.09.031.