Twist-in spring-skirt-like sphincterotome

A medical system for gaining access into a bodily lumen or stricture, the system comprising:

• an elongate catheter extending along a longitudinal axis from a proximal end to a distal end, the distal end having an outer diameter, and a lumen extending through the catheter;
• and
• a coiled engagement member comprising an elongate shaft and a coil fixedly attached to a distal end of the elongate shaft, the elongate shaft being movably disposed within the lumen of the catheter, the coil being disposed near the distal end of the catheter,
• wherein the elongate shaft has sufficient torsional rigidity to transmit rotational motion from a proximal end of the elongate shaft to the coil;
• wherein the coil comprises a wire that curves outwardly and proximally from the distal end of the elongate shaft to form a plurality of loops circumferentially disposed about the distal end of the elongate shaft and forming a spiral shape around the elongate shaft, the plurality of loops being configured to engage an inner tissue surface of a bodily lumen or stricture;
• wherein an end of the wire is attached to a proximal-most loop of the plurality of loops,
• wherein a diameter of an opening defined by the proximal-most loop is wider than the outer diameter of the distal end of the elongate catheter, and
• wherein the system comprises a first configuration in which the plurality of loops are disposed circumferentially about the distal end of the catheter, and a second configuration in which the plurality of loops are disposed distally of the distal end of the catheter.