Miniscopes.

Various miniscopes are available for cholangioscopy and pancreatoscopy, differing in the size of the external diameter and the instrumentation channel, the angulation system and the optical performance. For the per-oral route, the devices are inserted through a carrier duodenoscope. Ultra-thin instruments can be introduced into the biliopancreatic tract without the need for endoscopic sphincterotomy. Larger and steerable miniscopes are required for target biopsies and the approach to proximal lesions. Percutaneous cholangioscopy is more invasive and should be restricted to cases with a difficult anatomy or intrahepatic biliary disease. These techniques can be useful for the diagnosis of lesions that cannot be differentiated by indirect imaging methods. However, further studies are needed to evaluate their impact on clinical outcome. Controlled trials indicate that cholangioscopic lithotripsy is an effective and rapid alternative to other therapeutic methods for difficult bile duct stones. Mini-endoscopy is restricted to specific centres because of the high costs of the instruments, limited indications and the need for special endoscopic expertise.