Intraductal radiofrequency ablation can restore patency of occluded biliary self-expanding metal stents

Background: Endoscopic placement of self- expandable metallic stents (SEMS) is the mainstay of palliative measures for alleviating obstructive jaundice secondary to locally advanced and/or metastatic cholangiocarcinoma (cc). Although SEMS has longer patency as compared to plastic stents, they will occlude at a median of 120 days. Endobiliary application of RFA proved to be safe in pilot animal studies. The aim of the present study to test the safety and efficacy of iRFA to treat SEMS occlusion caused by tumor ingrowth and/or overgrowth in a cohort of patients (pts) with primary bile duct malignancy. Patients and methods: During May of 2010, 5 pts, all with cc, (m/f=2/3, mean age=65 y) were treated by iRFA because of occlusion of a previously inserted SEMS. There were 2 fully covered and 3 uncovered stent, with a median patency of 105 (17–240) days. The etiology of SEMS occlusion was tumor ingrowth in 2 pts and overgrowth in 3 pts. The 8 F through the scope RFA catheter was positioned at the occluded stent/bile duct segment(s) passing it over a 0.035-inch guidewire. The power was set according the length and the tightness of the stricture, but not exceeding 10 W. Energy was delivered in two minutes units with two minutes pause between sessions. A 7 F naso-biliary catheter was placed at the end of the procedure. Data expressed as median (range). Results: RFA applied at a median of 2 (1–3) locations for 2 (1–8) minutes using a median power of 8 (2–8) W delivering 960 (1320–3840)J energy for each locations. The number of RFA sessions was 2 (1–3) for each location. The overall energy delivered for a patient was 2880 (480–3840)J. After iRFA, diameter of bile duct stricture increased from a median of 2 to 4.7mm, the length of stricture reduced from 15 to 10.6mm, both p<0.05. The overall patency of SEMS after iRFA was 62 (9–236) days. In cases of tumor overgrowth patency of SEMS was 236 days as compared to 11 (9–62) days, which was observed in cases with stent occlusion due to tumor ingrowth. There was not clinically significant complication attributable to iRFA. Conclusion: In cases of primary cc., iRFA can be used safely to restore patency of occluded biliary SEMS due to tumor in- or overgrowth. It is likely, that SEMS occlusion caused by tumor overgrowth respond better to iRFA as compared to tumor ingrowth.