Percutaneous Intraductal Microwave Ablation of Malignant Biliary Strictures: Initial Experience

OBJECTIVE. Metallic stenting of malignant biliary strictures is the preferred method of palliation, because most patients present when the condition is inoperable. Most metallic stents, however, are occluded 6-8 months after deployment. Intraductal radiofrequency ablation has been used in previous studies to improve stent patency. The purpose of this study was to assess a single-center experience with percutaneous intraductal microwave ablation of malignant biliary strictures. MATERIALS AND METHODS. In this retrospective case series study, data on 12 patients with malignant biliary obstruction who underwent percutaneous intraductal microwave ablation followed by metallic stenting were evaluated. Ablation procedures were performed with generator frequencies of 902-928 MHz, power set at 6-10 W, and ablation time of 60-90 seconds in a temperature-controlled manner with target temperature set at 80°C. RESULTS. Causes of malignant biliary obstruction were pancreatic carcinoma in four patients, gastric antrum carcinoma in three, cholangiocarcinoma in two, metastasis in two, and gallbladder carcinoma in one patient. Percutaneous intraductal microwave ablation and metallic stenting were performed successfully in all patients. There was no procedural mortality or major complication. The most common minor complication was abdominal pain. Biliary decompression was achieved in all patients at the end of the first month. The mean follow-up time was 9.4 months. The median primary stent patency period was 231 days. There were two stent occlusions due to sludge formation, and two patients died during follow-up. CONCLUSION. Percutaneous intraductal microwave ablation of malignant biliary strictures is safe and feasible. Prospective randomized controlled studies with long-term results are warranted to determine the effectiveness of this technique in lengthening the stent patency period.