In addition, this procedure requires an experienced endoscopist who is competent at performing both EUS-FNA and ERCP.29 A recent study30 using endobiliary

radiofrequency ablation followed by self-expandable metallic stent placement showed proven results in the management of malignant biliary strictures. However, the bipolar radiofrequency ablation probe is 8F (2.6 mm) in diameter with a relatively blunt tip that is unlikely to pass through the high-grade strictures described in our series. Another case series31 reported successful percutaneous recanalization of anastomotic biliary strictures with a radiofrequency guidewire, typically used in cardiology. This radiofrequency device is currently unavailable for an endoscopic approach. Although there are studies reporting the use of the Soehendra

stent retriever to dilate tight strictures safely, cases Protein Tyrosine Kinase inhibitor have also been reported Alectinib molecular weight in which this technique was unsuccessful.8, 9, 10 and 32 The current study demonstrates that the wire-guided needle-knife technique is a salvage approach, gaining success in 9 of 10 failed cases when using conventional methods. Most cholangiocarcinomas are adenocarcinomas with abundant fibrous stroma.33 The stricture usually presents as concentric or annular thickening of the tumor tissue (up to 1 cm), which may lead to complete obstruction of the lumen.34 Benign biliary or pancreatic strictures are usually surrounded by rich fibrosis tissue because of hypoxemia secondary to decreased blood supply and thickening of the duct walls causing complete or near-complete obstruction of the lumen. Because of the pathologic features of these strictures, electronic cut of stricture lesions with the needle-knife is potentially reasonable and safe. The needle-knife technique is performed as follows. First, using

the blend current allows the cutting current to cut the thickened wall of the stricture while the coagulation current helps prevent bleeding. Second, the monofilament cut wire is extended to a suitable length about 3 mm beyond the distal tip, which is long enough to cut the thickened wall of stricture along the axis. Third, the Gemcitabine mw needle-knife is pushed through the stricture slowly and with constant pressure. Fourth, firm back-tension is applied to the guidewire to keep it in the right direction. Finally, the direction of the needle-knife should be observed with the use of fluoroscopy to see whether there is free gas under the diaphragm or retroperitoneal air around the extrahepatic bile duct or kidney during needle-knife electrocautery. If any abnormality is detected, the procedure should be terminated immediately because of safety concerns. In our series mild adverse events related to needle-knife technique occurred in two cases: one was self-limited bleeding and another was bile duct perforation.