Patent Description:
The pancreas and biliary system together form an important part of the digestive system. The pancreas and liver produce digestive fluids (pancreatic juice and bile) which help in the process of digestion (i.e., the breakdown of foods into parts which can be absorbed easily and used by the body). These digestive fluids are passed through the pancreatic duct and ducts of the biliary system prior to exiting into the intestine. Blockage of any of these ducts by, for example, a cancer, gallstone or scarring, may result in the duct becoming backed up and filled with fluid, requiring drainage.

<CIT> relates to a system for endoscopic ultrasound guided drainage which includes an access sheath extending longitudinally from a proximal end to a distal end and an access lumen extending therethrough from the proximal end to the distal end, a stylet slidably received within the access lumen, the stylet extending longitudinally from a proximal end to distal end and including a channel extending therethrough, the channel configured to receive a fluid therethrough, and a dilating sheath extending longitudinally from a proximal end to a distal end and including a dilating lumen extending therethrough. The dilating lumen is sized and shaped to slidably receive the access sheath.

<CIT> relates to a catheter which includes a flexible elongated catheter body that defines a needle-receiving, or probe-receiving, lumen, a retractable tissue-penetrable needle, or probe, and an electrode mounted on the distal portion of the catheter body. The needle provides a fluid passage for introducing fluid into tissue to permit the introduction of sclerotic agents for enhancing electrocoagulation of the tissue, heat-responsive drugs for improving the bonding to tissue surfaces, or vaso-constrictor drugs. The probe can also have a passage for fluid. The electrode can provide bipolar electro-coagulation of tissue in combination with an additional electrode mounted on the catheter body, or alternatively, the electrode can be employed in combination with either the needle or probe to establish a bipolar electro-coagulation path through tissue. The needle, or probe, in combination with an external electrode can be used to provide unipolar electro-coagulation, or ablation. In certain instances, the electrode can be used to provide a mapping function inside cardiac chambers.

<CIT> relates to a retractable safety penetrating instrument which includes a cannula and a needle disposed within the cannula and supported in a manner to automatically move proximally from an extended position wherein a sharp distal end of the needle protrudes from the cannula to a retracted position wherein the sharp distal end of the needle is protected in response to distal movement of the retractable safety penetrating instrument upon penetration into a cavity in the body. A retracting mechanism moves the needle proximally, is normally locked in a position preventing proximal movement of the needle and is released by distal movement of an operating member to trigger retraction of the needle.

All examples and embodiments not falling under the scope of the independent claim do not form part of the invention.

The present disclosure relates to a system for endoscopic ultrasound guided drainage comprising an access sheath including an elongated tube extending longitudinally from a proximal end to a distal end and including an access lumen extending therethrough from the proximal end to the distal end and a flexible tip coupled to the distal end of the elongated tube, the flexible tip biased to a curved configuration, a sharp slidably received within the access lumen, the sharp extending longitudinally from a proximal end to distal end and including a channel extending therethrough, the channel configured to receive a fluid therethrough, and a dilating sheath extending longitudinally from a proximal end to a distal end and including a dilating lumen extending therethrough, the dilating lumen sized and shaped to slidably receive the access sheath.

In an embodiment, the curved configuration of the flexible tip is a J-shape.

In an embodiment, the flexible tip is formed of a flexible polymeric material which permits the curved distal portion to be moved to a straightened configuration when the sharp is received therein.

In an embodiment, the access sheath is formed of a polymer coated metal coil to allow torque transmission in both the clockwise and counter clockwise direction.

In an embodiment, the access sheath includes laser cut sections for increased flexibility.

In an embodiment, the system includes a handle assembly coupled to a proximal end of each of the sharp, access sheath and dilating sheath.

In an embodiment, the handle assembly includes an actuator for moving the dilating sheath longitudinally relative to the access sheath.

In an embodiment, the handle assembly includes a generator connection coupled to the actuator.

In an embodiment, the dilating sheath including an insulated coil conductor at a distal end thereof configured to cauterize tissue.

In an embodiment, a distal portion of the sharp has a multi-facet puncture tip including holes to allow fluid to flow therethrough.

In an embodiment, the access sheath is fluoroscopically visible.

The present disclosure also relates to a system for endoscopic drainage comprising an access sheath extending longitudinally from a proximal end to a distal end and including an access lumen extending therethrough from the proximal end to the distal end, a sharp slidably received within the access lumen, the sharp extending longitudinally from a proximal end to distal tip and including a channel extending therethrough, the channel configured to receive a fluid therethrough, a dilating sheath extending longitudinally from a proximal end to a distal end and including a dilating lumen extending therethrough, the dilating lumen sized and shaped to slidably receive the access sheath, and a handle assembly including a sharp attachment mechanism coupled to a proximal end thereof, the sharp exiting the handle assembly via a proximal opening therein such that a proximal end of the sharp is coupled to the sharp attachment mechanism.

In an embodiment, the sharp attachment mechanism includes an injection port for injecting fluid into the channel of the sharp.

In an embodiment, the handle assembly includes an access sheath rotation knob at a proximal end thereof.

In an embodiment, the attachment mechanism is coupled to the handle assembly by one of a press fit, mechanical lock or friction fit.

The present disclosure also relates to a method for endoscopic ultrasound guided drainage comprising inserting an access sheath and a sharp through a working channel of an endoscope into a target duct within a body, the sharp extending through a lumen of the access sheath such that a distal tip of the sharp extends distally past a distal end of the access sheath so that the distal tip punctures the target duct, rotating the access sheath via a rotation knob at a proximal end thereof to adjust the direction of the sharp, injecting a contrast media through a channel of the sharp into the target duct to visually verify that the target duct is filled with fluids, and advancing a dilating sheath distally over the access sheath and into the target duct to dilate the target duct.

In an embodiment, the method further includes removing the sharp from the access sheath so that a distal portion of the access sheath reverts to a curved configuration.

In an embodiment, the method further includes dilating a puncture point in a surface of the target duct via an electrode of the dilating sheath.

In an embodiment, the electrode is an coil conductor.

In an embodiment, the method further includes cauterizing a surface of the target duct via a ceramic dilating sheath tip.

The present disclosure may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present disclosure is directed to endoscopic medical devices and, in particular, relate to endoscopic ultrasound (EUS) guided drainage. Exemplary embodiments describe a EUS guided drainage systems comprising a sharp for injecting a fluid into a fluid-filled duct, an access sheath through which the sharp is inserted and a dilating sheath for dilating the fluid-filled duct to facilitate drainage. It will be understood by those of skill in the art that the system and method of the present disclosure may be used to drain, for example, a bile duct, a pancreatic duct, cysts, gallbladder, etc. It should be noted that the terms "proximal" and "distal" as used herein are intended to refer to a direction toward (proximal) and away from (distal) a user of the device.

As shown in <FIG>, a system <NUM> according to an exemplary embodiment of the present disclosure comprises a sharp <NUM> for puncturing a fluid-filled tract and injecting a fluid (e.g., contrast media) thereinto and an access sheath <NUM> for providing access into the fluid-filled tract. The system <NUM> further comprises a dilating sheath <NUM> for dilating the tract to facilitate drainage. The system <NUM> is sized and shaped to be passed through a working channel of an endoscope to be visualized under ultrasound guidance. The system <NUM> may further comprise a handle assembly <NUM>, which remains outside of a living body while the sharp <NUM> and the access sheath <NUM> are inserted therein (e.g., along a tortuous path through a natural body lumen accessed via a naturally occurring body orifice). The handle assembly <NUM> permits the sharp <NUM> to be removed therefrom while the access sheath <NUM> remains in the target duct. The handle assembly <NUM> also includes an actuator for advancing the access sheath <NUM> beyond the dilating sheath <NUM> and another actuator for advancing the dilating sheath <NUM> over the access sheath <NUM> and into the target duct.

As shown in <FIG>, a sharp <NUM> extends along a longitudinal axis from a proximal end <NUM> to a distal end <NUM> and includes a channel <NUM> extending therethrough. The sharp <NUM> may be formed from Nitinol, Stainless Steel or any variety of bio-compatible metals with a similar stiffness. In an alternate embodiment, the sharp <NUM> may be formed of plastic or another suitable polymer. In an embodiment, the sharp <NUM> may be formed with a flexbile design such as, for example, a coil or a spiral cut design. The sharp <NUM> may be configured as a hypotube with a multi-facet distal tip <NUM> at a distal end thereof for puncturing the target duct. The tip <NUM> according to this embodiment include holes <NUM> open to the channel <NUM> to allow fluid injection (e.g. contrast media) from the proximal end through the channel <NUM> to exit the distal end of the device. In an exemplary embodiment, the tip <NUM> may be attached to the hypotube via welding, bonding, or mechanical fastening such as threads. In an alternate embodiment, the hypotube <NUM> and tip <NUM> may be formed of a plastic or any other suitable polymer. In this embodiment, the plastic tip <NUM> may be constructed from one or two components. In the single body design, the tip <NUM> may be constructed, for example, through molding. In the double component design, a distal tapered portion <NUM> may be attached to a base tube <NUM>, as seen in <FIG>, via adhesive, melting or heat shrink application. The channel <NUM> extends from the proximal end <NUM> of the sharp <NUM> along the longitudinal axis thereof to a distal end <NUM> extending through the tip <NUM>. In another exemplary embodiment, the puncture sharp <NUM> may be formed as a hypotube with either a sharpened wall or beveled edge along the circumference of the distal leading edge to promote puncture and allow a large opening for fluid injection. In this embodiment, the channel <NUM> extends from a proximal portion <NUM> of the sharp <NUM> and is open at the distal end <NUM> of the sharp <NUM>. A fluid such as, for example, contrast media, may be injected into the target duct via the channel <NUM> to verify that the target duct is filled with fluid (e.g., digestive fluid).

As shown in <FIG>, the access sheath <NUM> includes a hollow tube <NUM> and a flexible tip <NUM>. The hollow tube <NUM> extends longitudinally from a proximal end <NUM> to a distal end <NUM> and includes a lumen <NUM> extending therethrough. The lumen <NUM> is sized and shaped so that the sharp <NUM> can slight through. In particular, an inner diameter of the lumen <NUM> in this embodiment substantially corresponds to an outer diameter of the sharp <NUM> so that when the sharp <NUM> is received therein it completely fills the lumen <NUM> of the hollow tube <NUM>. Flexible tip <NUM> extends from a proximal end <NUM> to a distal end <NUM> and includes a lumen <NUM> extending therethrough. Similar to the hollow tube lumen <NUM>, the flexible tip lumen <NUM> is sized and shaped to slidably receive the sharp <NUM> therein and may have an inner diameter substantially equal to the inner diameter of the hollow tube <NUM>. In particular, an inner diameter of the flexible tip lumen <NUM> in this embodiment substantially corresponds to an outer diameter of the sharp <NUM> so that when the sharp <NUM> is received therein it completely fills the lumen <NUM> of the flexible tip <NUM> to facilitate puncturing the target duct when the access sheath <NUM>, with the sharp <NUM> received therein, is inserted into the target duct. Furthermore, the flexible tip <NUM> of this embodiment may be biased to assume, when not constrained, a desired a curvature along a distal portion <NUM> thereof to direct the inserted sharp <NUM> and a guidewire toward a target site. In one exemplary embodiment, the distal portion <NUM> of the flexible tip <NUM> is biased toward a J configuration (i.e., a curve in which the distal portion <NUM> arcs away from an axis of more proximal portions of the sheath <NUM> along an arc of <NUM>° or less) for directing a guidewire in another desired direction. The distal end <NUM> of the flexible tip <NUM> may have a taper or a rounded edge to minimize initial puncture forces and ensure the flexible tip <NUM> follows the sharp tip <NUM> into the target area. The proximal end <NUM> of the flexible tip <NUM> is coupled to the distal end <NUM> of the hollow tube <NUM> such that the hollow tube lumen <NUM> is aligned with and open to the lumen <NUM> of the flexible tip <NUM>.

The flexible tip <NUM> may be formed of a polymer that is sufficiently flexible so that when the sharp <NUM> is received therein, the distal portion of the flexible tip122 is straightened. Once the sharp <NUM> is extended distally therefrom, however, the flexible tip <NUM> is permitted to revert to its curved configuration. The curved configuration is maintained when a distal floppy end of the guidewire is within the flexible tip <NUM>. The hollow tube <NUM> and the flexible tip <NUM> are formed of different materials. In an exemplary embodiment, the access sheath <NUM> is formed of braid reinforced polyamide. In another embodiment, the access sheath <NUM> is formed of multiple polymeric layers such as multilayer braid constructions. In a further embodiment, the access sheath <NUM> is insulated or coated along its length or at portions thereof. For example, the hollow tube <NUM> may be formed of PTFE, ETFE, or other polymer coated single-wire or dual-wire-counter-wound metal coils that allow transmission of torque in both clockwise and counter clockwise direction in <NUM>-to-<NUM> ratio. The torque transmission permits the user to rotate and direct the guidewire with the formed tip toward a target site and the coating allows for compatibility with electrosurgical activation as will be discussed in more detail below. The coating also reduces friction and promotes electrosurgical compatibility with the metal used to form the hollow tube <NUM>. It will be understood that insulation or coating is only required on portions of the access sheath <NUM> that could come into contact with the operator or patient. In another exemplary embodiment, the hollow tube <NUM> is formed as a parylene or a similar polymer coated solid or laser cut hypotube <NUM> that allows transmission of torque in both the clockwise and counter-clockwise directions in a <NUM>-to-<NUM> ratio. In an embodiment, the solid hypotube <NUM> is made of Nitinol and has an inner diameter of <NUM> +/- <NUM> (<NUM> +/-<NUM> inches) and an outer diameter of <NUM> +/- <NUM> (<NUM> +/- <NUM> inches). In another embodiment, the hypotube <NUM> has laser cut sections that increase flexibility in the hypotube. An exemplary laser cut design can be seen in <FIG> with cuts <NUM> tapered over the length of the device. The cuts <NUM> are concentrated in certain areas where increased flexibility is needed due to aspects of the procedure and the tortuosity of the path along which the scope extends. The parylene coating reduces friction and promotes electrosurgical compatibility with the metal used to form the hollow tube <NUM>. The access sheath <NUM> assembly including the hollow tube <NUM> and the flexible tip <NUM> is fluoroscopy and EUS compatible. For example, the flexible tip <NUM> polymer may be loaded with Bismuth or Tungsten. In another example, marker bands may be added to the flexible tip <NUM> to facilitate visual determination of the position and orientation of the device. In a further example, echogenic features may be added to the hollow tube <NUM> to enhance ultrasonic imaging of the device as would be understood by those skilled in the art.

The dilating sheath <NUM> similarly extends longitudinally from a proximal end <NUM> to a distal end <NUM> and includes a lumen <NUM> extending therethrough and a distal portion <NUM>. The lumen <NUM> is sized and shaped to slidably receive the access sheath <NUM> therein so that the dilating sheath <NUM> may be advanced over the access sheath <NUM> to the target duct to dilate the obstructed duct, thereby facilitating drainage thereof. The dilating sheath <NUM> may be a cold dilator such as, for example, a sohendra type dilator and/or a balloon dilator. Alternatively, the dilating sheath <NUM> may be a hot dilator such as, for example, a cystome or needleknife, which includes electrosurgical capabilities. For example, the dilating sheath <NUM> may include an electrode <NUM> extending along the distal portion <NUM> (immediately adjacent the distal end <NUM>) thereof for cauterizing tissue. In particular, the dilating sheath <NUM> may be configured to utilize electrosurgical dissection to facilitate dilation or to burn a lesion as the dilating sheath <NUM> is inserted into the target duct. For example, the electrode may be an insulated coil conductor that is exposed at a distal end to supply cut/cautery energy. In another example, the distal portion <NUM> of the dilating sheath may be formed as a a tip (not shown) made from ceramic or another material with either a wire wrapped around the base or a gold-based painted on pattern extending to the distal end <NUM> of the sheath. It will be understood that the pattern may, in other examples, be any suitable material such as platinum, silver, titanium, stainless steel, niobium, titanium nitride, tungsten, copper or graphite-based inks. The tip may be configured as a cone, dome or any of a variety of configurations facilitating insertion into the target duct. In another embodiment, using "cold" dilation, the dilating sheath <NUM> may have a balloon (not shown) attached to the distal end <NUM>. The balloon may be used in conjunction with previous tip designs or by itself. The balloon may be connected to a pump that inflates/deflates the balloon once it is in position. Once the dilating sheath <NUM> has been advanced over the access sheath <NUM> and inserted into the target duct, the dilating sheath <NUM> may be actuated to dilate or expand the target duct. For example, the dilating sheath <NUM> may have one or more stepped diameters at discrete distances from the distal end or one or more additional sheaths that may be independently actuated to expand the path to the target duct. The dilating sheath <NUM> may be fluoroscopically and EUS compatible. That is, the properties of the tip and the electrode provide visibility which aids with dilation of the access region.

As shown in <FIG>, the handle assembly <NUM> includes a grip portion <NUM> extending from a proximal end <NUM> to a distal end <NUM> and an extension portion <NUM> coupled to the distal end <NUM> of the grip portion <NUM> and couplable to the proximal end <NUM> of the dilating sheath <NUM>. The access sheath <NUM> may be received within and coupled to the grip portion <NUM> such that the access sheath <NUM> extends through the lumen <NUM> of the dilating sheath <NUM>. The sharp <NUM> extends through the grip portion <NUM> and the extension portion <NUM> with the proximal end of the sharp <NUM> extending proximally of the proximal end <NUM> of the grip portion and the length of the sharp <NUM> extending through the lumen <NUM> of the access sheath <NUM>. Since the proximal end <NUM> of the sharp <NUM> extends proximally from the grip portion <NUM>, the sharp <NUM> may be removed from the access sheath <NUM> by simply pulling the sharp <NUM> proximally relative to the handle assembly <NUM>. The distal end <NUM> of the sharp <NUM> extends distally past the distal end <NUM> of the access sheath <NUM> so that the tapered tip <NUM> may puncture the target duct once the system <NUM> has been inserted into the body. The handle assembly <NUM> also includes an actuator <NUM> which moves the dilating sheath <NUM> longitudinally relative to the access sheath <NUM>. In particular, the actuator <NUM> may include a tab that is moved distally and proximally with respect to the grip portion <NUM> of the handle assembly <NUM> to advance and retract, respectively, the dilating sheath <NUM> over the access sheath <NUM>. The handle assembly <NUM> may include an access sheath lock <NUM>' which locks how far the access sheath <NUM> extends beyond the dilating sheath <NUM>. The handle may also include a dilating sheath lock (not shown) which locks the dilating sheath <NUM> in a specific location. In use, the access sheath lock may be unlocked while the access sheath/style assembly is through into the target tissue beyond the dilating sheath tip, then the dilating sheath <NUM> is unlocked and the dilating sheath <NUM> is advanced over the access sheath <NUM>. As noted above, in embodiments in which the dilating sheath <NUM> includes an electrode, an active wire (not shown) is used to provide a current to the electrode. In a preferred embodiment, the active wire is long enough to run the length of the device in the extended position (before any cautery or puncture activation) and the contracted position (puncture and cautery activated). In the current embodiment, the wire may be coiled around the access sheath <NUM> in the handle assembly <NUM>. Coiling the wire prevents it from kinking during handle actuation and while permitting the wire to have a length sufficient for both the extended and contracted handle configurations. In an alternate embodiment, the handle assembly <NUM> may include a generator connection <NUM> located at a proximal portion thereof. The generator connection <NUM> may be attached to the actuator <NUM> and may move with the actuator during actuation. Thus, in this embodiment, slack management of the active wire <NUM> would not be required. The handle assembly <NUM> further includes an access sheath rotation knob <NUM> located at a proximal end thereof. The rotation knob <NUM> is coupled to the proximal end of the access sheath <NUM> via an access sheath hub (not shown) at the handle and is rotatable, allowing transmission of torque in both the clockwise and counter clockwise direction in a <NUM>-to-<NUM> ratio.

The handle assembly <NUM> includes a sharp attachment mechanism <NUM> which allows the sharp <NUM> to be easily attached to, and removed from, the handle assembly <NUM>. The sharp <NUM> extends proximally from a proximal end of the handle assembly <NUM>, with a proximal end <NUM> thereof coupled to the sharp attachment mechanism <NUM>. The sharp attachment mechanism <NUM> also allows for fluid to be injected into the sharp channel <NUM> through an injection port <NUM>. It is noted that in an exemplary embodiment, the injection port <NUM> may be added to the access sheath <NUM> to allow injection through the access sheath lumen. A first exemplary sharp attachment mechanism <NUM> uses a "top hat" design as seen in <FIG>. This "top hat" mechanism <NUM> utilizes a mechanical side lock <NUM> to attach the sharp <NUM> to the handle assembly <NUM>. When side lock <NUM> is depressed, an inner lumen (not shown) of the lock <NUM> aligns with a handle top feature <NUM>, unlocking the sharp <NUM> from the handle assembly <NUM>. The "top hat" attachment mechanism <NUM> also engages an inner portion of the rotation knob <NUM> via the side lock <NUM> to facilitate rotation of the access sheath <NUM>. Another exemplary embodiment of the sharp attachment mechanism <NUM> uses a "press fit" design as seen in <FIG>. The "press fit" attachment <NUM> uses friction fit to attach the sharp <NUM> to the handle assembly <NUM>. The <NUM>-degree component <NUM> uses a friction fit to hold the sharp within a lumen <NUM> of the access sheath rotation knob <NUM>. Similar to the "top hap" design <NUM>, the <NUM>-degree component <NUM> of the "press fit" design <NUM> includes a side port <NUM> for injection of fluid into the sharp channel <NUM>. Another exemplary attachment mechanism <NUM> uses a "harp" design as seen in <FIG>. This design utilizes a mechanical lock to attach the sharp <NUM> to the handle <NUM>. The "harp" attachment <NUM> includes two side wings <NUM> which may be pressed simultaneously inward so that a clamp <NUM> that holds the sharp <NUM> to the handle <NUM> is released, allowing the sharp <NUM> to be retracted into the handle assembly <NUM>. The "harp" attachment <NUM> includes an injection port <NUM> at its proximal end. A further exemplary embodiment of the sharp attachment mechanism <NUM> uses a "snap cap" design as seen in <FIG>. The "snap cap" attachment <NUM> includes a press fit lock to attach the sharp <NUM> to the handle <NUM>. The attachment includes a proximal half portion <NUM> and a distal half portion188, with the distal half portion <NUM> secured in the handle assembly <NUM>. The proximal half portion <NUM> is removably attached to the distal half portion <NUM> via a locking slot <NUM> extending about the diameter of the bottom half portion <NUM>. The proximal half portion <NUM> includes a coil portion <NUM> that moves over the distal half portion <NUM> of the design and sits in the locking slot <NUM> when the two components are attached. Similar to the "top hat" and "harp" attachments <NUM>, <NUM>, the "snap cap" attachment <NUM> includes an injection port at its proximal end <NUM>.

According to a method using the system <NUM> according to an exemplary embodiment of the present disclosure, the system <NUM> is inserted through a working channel of an endoscope via, for example, ultrasound guidance to a target duct within the body. In an insertion configuration, the access sheath <NUM> according to an exemplary embodiment is fully housed within the dilating sheath <NUM> to protect an interior surface of a working channel of an endoscope or other insertion device through which the system <NUM> is inserted from the sharp distal tip <NUM> of the sharp <NUM>. Upon insertion through the endoscope, the dilating sheath <NUM> may be in a proximal position so that the dilating sheath <NUM> does not extend distally over the portion of the access sheath <NUM> being inserted into the target duct. At this point, the distal end <NUM> of the sharp <NUM> extends distally past the distal end <NUM> of the access sheath <NUM>. The access sheath <NUM> and sharp <NUM> is then advanced distally to penetrate the target duct. Once the sharp <NUM> and the access sheath <NUM> have been inserted into the target duct, contrast media (e.g., radiopaque dye) may be inserted, via the injection port <NUM>, through the channel <NUM> of the sharp <NUM>, out of the holes <NUM> of the sharp tip <NUM> into the target duct so that a user of the system <NUM> may visually verify that the duct has been filled with fluid and requires drainage. The sharp <NUM> may then be removed from the access sheath <NUM> by drawing the sharp <NUM> proximally relative to the access sheath <NUM> so that only the access sheath <NUM> remains in the target duct. Upon removal of the sharp <NUM>, the flexible tip <NUM> of the access sheath <NUM> is freed to revert to the curved configuration to either anchor the access sheath <NUM> in the target duct or to direct a guidewire therethrough in a desired direction. If the access sheath <NUM> is in the target duct, a guidewire may be inserted through the lumen <NUM> of the access sheath <NUM> and into the target duct. As would be understood by those skilled in the art, a tip of the guidewire passed through the access sheath <NUM> will be directed in a direction corresponding to a curvature of the distal portion <NUM> of the access sheath <NUM> to contact an interior surface of the target duct. Rotation of the handle may then be used to manipulate the position of the j-shape, thus allowing the operator to advance the guidewire in a chosen direction. It will be understood that direction may or may not be set before guidewire advancement. As would be understood by those skilled in the art, prior to inserting the guide wire into the access sheath <NUM>, the access sheath <NUM> may be rotated by manipulating the access sheath rotation knob <NUM> to direct the curved flexible tip <NUM> toward a desired direction.

Once the access sheath <NUM> has been anchored in the target duct, the dilating sheath <NUM> may be advanced over the access sheath <NUM> into the target duct. At this point, the generator connection <NUM> may be connected to a surgical generator such as, for example, a high-frequency (HF), alternating current (AC) surgical generator to provide an active current to the wire <NUM>. As described above, the dilating sheath <NUM> is advanced by moving the actuator <NUM> distally with respect to the grip portion <NUM> of the handle assembly <NUM>. The distal end <NUM> of the dilating sheath <NUM> is configured to facilitate insertion of the dilating sheath <NUM> into the target duct and to be advanced to a site at which the duct is blocked. In one embodiment, an electrode at the distal end <NUM> is activated to electrosurgically dissect and/or cauterize a surface tissue of the target duct to facilitate insertion therein. Insertion of the dilating sheath <NUM> over the site of the blockage enlarges the portion of the duct surround the obstruction to permit drainage of the target duct. It will be understood by those of skill in the art that the dilating sheath <NUM> may dilate the target duct in any of a number of ways. In one previously described example, the dilating sheath <NUM> includes an expansible balloon activated to expand the target duct. It will be understood by those of skill in the art that a user may also implement further treatment of the blocked duct. In particular, a stent may be implanted in the duct at the location of the blockage to maintain the duct in an enlarged configuration to ensure continued drainage thereof.

Claim 1:
A system for endoscopic ultrasound guided drainage, comprising:
an access sheath (<NUM>) including an elongated tube (<NUM>) extending longitudinally from a proximal end (<NUM>) to a distal end (<NUM>) and including an access lumen (<NUM>) extending therethrough from the proximal end to the distal end and a flexible tip (<NUM>) coupled to the distal end of the elongated tube, the flexible tip biased toward a curved configuration;
a sharp (<NUM>) slidably received within the access lumen, the sharp extending longitudinally from a proximal end (<NUM>) to a distal end (<NUM>) and including a fluid channel (<NUM>) extending therethrough to at least one opening (<NUM>) in a distal end of the sharp, the sharp being configured so that, when the sharp is received within the distal end of the access sheath, the flexible tip of the access sheath is straightened; and
a dilating sheath (<NUM>) extending longitudinally from a proximal end to a distal end and including a dilating lumen (<NUM>) extending therethrough, the dilating lumen sized and shaped to slidably receive the access sheath,
wherein the elongated tube (<NUM>) and the flexible tip (<NUM>) are formed of different materials.