With the development of endoscopic technology, endoscopic retrograde cholangiopancreatography (ERCP) has been widely used in the diagnosis and treatment of extrahepatic cholangiocarcinoma.In patients with extrahepatic cholangiocarcinoma, cytological brushing performed concurrently with ERCP had a lower pathologically positive rate and increased the times of ERCPs, increased the risk of postoperative complications at the same time.The present study aims to compare the efficacy and safety outcomes of Spyglass+RFA Versus Cytobrush+RFA for Extrahepatic Cholangiocarcinoma.

Endoscopic retrograde cholangiopancreatography (ERCP) has been used as the primary method for the diagnosis of biliary strictures and the treatment of extrahepatic cholangiocarcinoma. However, the accurate visual diagnosis of malignant biliary strictures and assessment of the extent of a lesion are not possible by ERCP, and treatment of extrahepatic cholangiocarcinoma by ERCP procedures is sometimes difficult. In patients with extrahepatic cholangiocarcinoma, cytological brushing performed concurrently with ERCP had a lower pathologically positive rate and increased the times of ERCPs, increased the risk of postoperative complications at the same time. Spyglass enables direct visualization of the biliary tract and the sampling of suspicious lesions, together with radiofrequency ablation.Endoscopic radiofrequency ablation (RFA) is an emerging technique for the palliation of inoperable malignant biliary strictures (MBSs). In a dozen published studies, this novel approach has shown better safety and feasibility, as well as improvement in overall survival (OS). The present study aims to compare the efficacy and safety outcomes of Spyglass+RFA Versus Cytobrush+RFA for Extrahepatic Cholangiocarcinoma.

Inclusion Criteria:

• Age >18 years ;
• Patients with high suspicion of extrahepatic cholangiocarcinoma such as unexplained bile duct stenosis or elevated CA19-9 were found according to relevant imaging studies or symptoms;
• Willing to abide by the research procedures and sign the informed consent.

Exclusion Criteria:

• Myocardial infarction within 3 months;
• Renal insufficiency (Scr>177 umol/L);
• Serious cardiovascular and cerebrovascular or respiratory diseases before surgery;
• Preoperative shock manifestations, such as hypotension ( Systolic blood pressure <90mmHg) or increased heart rate (>120 beats/min);
• Pregnancy and lactation;
• Allergic to NSAIDs; Other clinical observation trials or those who have participated in other clinical trials within 60 days;
• Cases deemed inappropriate by the investigator (such as those with clear contraindications to ERCP).