Methylene blue aided cholangioscopy for the detection of neoplastic biliary lesions

Introduction: Patients with biliary malignancies do have a poor prognosis. Aim of the current feasibility study was to investigate the value of methylene blue aided cholangioscopy for the early detection of neoplastic biliary lesions.

Methods: Patients with suspected biliary lesions (ultrasonography or MRT) or long standing primary sclerosing cholangitis (PSC) were scheduled for ERCP with subsequent cholangioscopy (FCP-9P) using the mother and baby technique. The intra- and extrahepatic biliary tree was inspected with cholangioscopy and subsequently stained with 20ml of methylene blue at a final concentration of 0.1% through the working channel of the cholangioscope. Visible mucosal abnormalities were graded after staining and targeted biopsies were performed.

Results: In 11 patients methylene blue aided cholangioscopy after endoscopic sphincterotomy could be performed. Intraluminal, circumscript inflammation was readily visible in a subset of patients with PSC (n=4). In patients with suspected lesions methylene blue aided cholangioscopy could exclude malignancies in 5 cases. In two patients irregular and unstained areas could be diagnosed at the hilus and in the right hepatic biliary duct. Targeted biopsies revealed neoplasia confirming Klatskin formation.

Conclusions: Methylene blue aided cholangioscopy is a newly discovered diagnostic tool that may be helpful for diagnosing neoplastic biliary lesions. The procedure is safe and well tolerated. Direct observation of intraluminal mucosa in conjunction with methylene blue staining allows to highlight subtle mucosal changes and offers the possibility for targeted biopsies.