Current status of endoscopic biliary drainage for unresectable malignant hilar biliary strictures

The management of jaundice and cholangitis is important for improving the prognosis and quality of life of patients with unresectable malignant hilar biliary strictures (UMHBS). In addition, effective chemotherapy, such as a combination of gemcitabine and cisplatin, requires the successful control of jaundice and cholangitis. However, endoscopic drainage for UMHBS is technical demanding, and continuing controversies exist in the selection of the most appropriate devices and techniques for stent deployment. Although metallic stents (MS) are superior to the usual plastic stents in terms of patency, an extensive comparison between MS and "inside stents", which are deployed above the sphincter of Oddi, is necessary. Which techniques are preferred remains as yet unresolved: for instance, whether to use a unilateral or bilateral drainage, or a stent-in-stent or side-by-side method for the deployment of bilateral MS, although a new cell design and thin delivery system for MS allowed us to accomplish successful deployments of bilateral MS. The development of techniques and devices for re-intervention after stent occlusion is also imperative. Further critical investigations of more effective devices and techniques, and increased randomized controlled trials are warranted to resolve these important issues.