A biliary access sheath may include an elongate proximal tube portion having a fixed outer diameter and permanently attached to a distal tube portion having an outer diameter that may be constricted and expanded. The distal portion may be configured as a self-expanding tube similar to a self-expanding stent construction, being constrained during introduction into a proximal portion of the biliary tree, and released to anchor the distal sheath portion therein. In another aspect, a method for introducing an intra-ductal endoscope may use a biliary access sheath as herein described.
