Intraductal endoscopic radiofrequency ablation for the treatment of hilar non-resectable malignant bile duct obstruction

AIM: To evaluate the safety and technical success of endoscopic radiofrequency ablation(RFA) for palliative treatment of malignant hilar bile duct obstruction. METHODS: In this study, a recently CE and FDA-approved endoscopic RFA catheter was first tested in an ex vivo pig liver model to study the effect of electrosurgical variables on the extent of the area of induced necrosis. Subsequently, a retrospective analysis was conducted of all patients treated with endoscopic RFA for malignant biliary obstruction at our center between February 2012 and April 2013. All patients received an additional plastic stent implantation into the biliary tree following RFA. RESULTS: In the pig model, ablation time of 60-90 seconds using the bipolar soft coagulation mode at 8-10 watts with an effect of 8 was found to be the most feasible setting. Twelve patients(5 females, 7 males; mean age, 70 years) underwent 19 endoscopic RFA(range, 1-5) sessions. Deployment of RFA was successful in all patients. Systemic chemotherapy was administered in four patients. We observed biliary bleeding 4-6 wk after the intervention in three cases and two of these patients died: in one patient, spontaneous hemobilia occurred, whereas bleeding started during stent extraction in the other. In the third patient, bleeding was stopped by insertion of a non-covered self-expanding metal stent. Another three patients developed cholangitis during follow-up. Seven patients died during follow-up and median survival was 6.4 mo(95%CI: 0.05-12.7) from the time of the first RFA. CONCLUSION: Endoscopic RFA is an easy to perform and technically highly successful procedure. However, hemobilia possibly associated with RFA occurred in three of our patients. Therefore, larger prospective studies are needed to further evaluate the safety and efficacy of this promising new method.

SEMS vs cSEMS in duodenal and small bowel obstruction:High risk of migration in the covered stent group

AIM:To compare clinical success and complications of uncovered self-expanding metal stents(SEMS)vs covered SEMS(cSEMS)in obstruction of the small bowel.METHODS:Technical success,complications and outcome of endoscopic SEMS or cSEMS placement in tumor related obstruction of the duodenum or jejunum were retrospectively assessed.The primary end points were rates of stent migration and overgrowth.Secondary end points were the effect of concomitant biliary drainage on migration rate and overall survival.The data was analyzed according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines.RESULTS:Thirty-two SEMS were implanted in 20 patients.In all patients,endoscopic stent implantation was successful.Stent migration was observed in 9 of16 cSEMS(56%)in comparison to 0/16 SEMS(0%)implantations(P=0.002).Stent overgrowth did not significantly differ between the two stent types(SEMS:3/16,19%;cSEMS:2/16,13%).One cSEMS dislodged and had to be recovered from the jejunum by way of laparotomy.Time until migration between SEMS and cSEMS in patients with and without concomitant biliary stents did not significantly differ(HR=1.530,95%CI0.731-6.306;P=0.556).The mean follow-up was 57±71 d(range:1-275 d).CONCLUSION:SEMS and cSEMS placement is safe in small bowel tumor obstruction.However,cSEMS is accompanied with a high rate of migration in comparison to uncovered SEMS.