Devices, systems, and methods for access cannula advancement

Abstract

An apparatus includes an access cannula (102), a piercing element, a handle (200). The access cannula (102) includes a lumen extending therethrough. The access cannula (102) is sized and shaped to extend through an endoscope shaft (240) to a target tissue within a living body. The piercing element is sized and shaped to extend through the lumen of the access cannula (102) and to project distally from a distal end of the access cannula (102). The handle (200) includes a handle body and a mechanism for advancing the access cannula (102) from a proximal position relative to the piercing element, in which a piercing tip (106) of the piercing element is exposed distally of a distal end of the access cannula (102), to a distal position relative to the piercing element, in which the distal end of the access cannula (102) covers the piercing tip (106) of the piercing element.

Description

[0001] Inventors: Lamin N. Tchelie; Christopher A. Benning; and Gregory Thomas Hughes

[0002] CLAIM

[0003] This disclosure claims priority to U.S. Provisional Patent Application Serial No. 62 / 987,740, filed March 10, 2020; the disclosure of which is incorporated herein by reference. TECHNICAL FIELD

[0004] The present disclosure relates to endoscopic ultrasound (EUS) access devices, systems, and methods for accessing an anatomical structure, such as the pancreaticobiliary tree. BACKGROUND

[0005] Endoscopic ultrasound (EUS) access procedures, i.e., access procedures performed under ultrasound guidance, can be used to access anatomical structures, such as the pancreaticobiliary tree or the liver. Pancreaticobiliary access procedures, such as procedures to penetrate a bile duct to insert a stent and bypass an obstruction, can be different from other types of access procedures because the target anatomical structure is very narrow. Many EUS access devices are not sufficiently flexible for such procedures, and even when sufficiently flexible, other difficulties can be encountered. For example, an elongate sharp can easily form an initial puncture hole, but there is a risk that the sharp is extended too far such that the sharp penetrates through the entire thickness of the bile duct to access other non-target tissue from the bile duct, creating an unwanted opening in the bile duct.

[0006] Furthermore, if the access cannula is not inserted far enough into the anatomical structure before the sharp is removed, the access cannula can be left outside the structure after the sharp is withdrawn. Thus, it is important for the clinician to obtain the correct puncture depth. It is sometimes difficult for the clinician to assess the penetration depth because the clinician can have difficulty determining the transition point between the sharp and the access cannula under EUS and / or fluoroscopy to confirm that the access cannula has been inserted into the structure to the appropriate depth. SUMMARY

[0007] The present disclosure relates to a device comprising an access cannula, a puncture element, and a handle. The access cannula comprises a lumen extending therethrough. The access cannula is sized and shaped to extend through an endoscope shaft to a target tissue within a living body. The puncture element is sized and shaped to extend through the lumen of the access cannula and to project distally beyond a distal end of the access cannula. The handle comprises a handle body and a mechanism for advancing the access cannula from a proximal position relative to the puncture element to a distal position relative to the puncture element, wherein in the proximal position relative to the puncture element, a puncture tip of the puncture element is exposed distally of the distal end of the access cannula, and in the distal position relative to the puncture element, the distal end of the access cannula covers the puncture tip of the puncture element.

[0008] In one embodiment, at the proximal position, the piercing tip extends a first predetermined distance relative to a distal end of the access cannula, and when the advancement mechanism is actuated, the access cannula is advanced relative to the piercing element at least the first predetermined distance.

[0009] In one embodiment, the device further comprises a rotating hub fixed to the access cannula and coupled to a proximal end of the handle body, the rotating hub being rotatable relative to the handle body and slidable relative to the handle body a second predetermined distance, and a cap fixed to the piercing element and couplable to the rotating hub, wherein when the cap and the rotating hub are coupled, the piercing tip extends the first predetermined distance relative to a distal end of the access cannula.

[0010] In one embodiment, the proximal end of the handle comprises an end cap into which a distal portion of the rotating hub is inserted to couple the rotating hub to the handle, the end cap having a seat against which the first spring is positioned.

[0011] In one embodiment, the rotating hub comprises a first proximal flange and a second distal flange between which the shaft extends, the shaft having a washer and a second spring slidable thereon and constrained between the first and second flanges.

[0012] In one embodiment, the end cap further comprises a deformable tab at its proximal end, the tab allowing insertion of the washer therein and preventing retraction of the washer, such that when the rotating hub is inserted into the end cap, the washer is positioned against the first spring at a distal end and against the deformable tab at a proximal end.

[0013] In one embodiment, the cap has a distal portion sized and shaped to cover a proximal portion of the rotating hub and two wings attached thereto, each wing having a tab extending radially inward from a distal end of the wing.

[0014] In one embodiment, when the cap is advanced over the rotating hub, the tabs extending from the wings lock onto the first flange of the rotating hub such that the cap and the rotating hub are fixed to each other, wherein depressing a proximal portion of the wings causes the distal ends to be stretched such that the wings unlock from the first flange.

[0015] In one embodiment, the advancement mechanism is loaded by locking the wings onto the first flange, thereby pushing the washer into the end cap a third predetermined distance and compressing the first and second springs, and releasing the cap to push the washer proximally back against the deformable tab and the rotating hub a third distance while the second spring remains compressed between the washer and the second flange.

[0016] In one embodiment, the loaded advancement mechanism is unloaded by unlocking the wings from the first flange, causing the second spring to push the second flange of the rotating hub distally relative to the cap.

[0017] In one embodiment, the device further comprises a cap fixed to the piercing element; and a rotating hub fixed to the access cannula. The rotating hub connected to the cap proximal end of the handle automatically loads the advancement mechanism.

[0018] In one embodiment, the advancement mechanism is unloaded by unlocking the cap from the rotating hub.

[0019] In one embodiment, the device further comprises a cap fixed to the piercing element; and a rotating hub fixed to the access cannula, the rotating hub having a living hinge that prevents longitudinal movement of the rotating hub relative to the handle body in an extended position, the living hinge depressible into a depressed position by a mechanism in the cap such that the rotating hub is longitudinally movable relative to the handle body.

[0020] In one embodiment, the device further comprises a spring loaded against the rotating hub when the living hinge is in the extended position, wherein depressing the living hinge unloads the spring and moves the rotating hub a predetermined distance relative to the handle body. The present disclosure is also directed to a device comprising: an access cannula comprising a lumen extending therethrough, the access cannula sized and shaped to extend through a scope shaft to a target tissue within a living body; a piercing element sized and shaped to extend through the lumen of the access cannula and distally out of a distal end of the access cannula; and a handle comprising a handle body, a rotating hub fixed to the access cannula, and a cap fixed to the piercing element, the handle comprising a mechanism for advancing the rotating hub relative to the handle body from a proximal position to a distal position while the cap remains substantially stationary relative to the handle body.

[0021] The present disclosure is also directed to a system comprising: a scope comprising a scope shaft; an access cannula comprising a lumen extending therethrough, the access cannula sized and shaped to extend through the scope shaft to a target tissue within a living body; a piercing element sized and shaped to extend through the lumen of the access cannula and distally out of a distal end of the access cannula; and a handle comprising a handle body, a rotating hub fixed to the access cannula, and a cap fixed to the piercing element, the handle comprising a mechanism for advancing the rotating hub relative to the handle body from a proximal position to a distal position while the cap remains substantially stationary relative to the handle body.

[0022] Further, the present disclosure is directed to a method. The method includes advancing an access cannula through an endoscope shaft to a target tissue in a living body, the access cannula including a lumen extending therethrough; advancing a piercing element through the lumen of the access cannula such that a piercing tip of the piercing element extends distally beyond a distal end of the access cannula, a cap being secured to a proximal end of the piercing element; connecting the cap to a proximal end of a handle; and actuating a mechanism in the handle to advance the access cannula from a proximal position relative to the piercing element to a distal position relative to the piercing element, wherein in the proximal position the piercing tip is exposed distally of the distal end of the access cannula, and in the distal position the distal end of the access cannula covers the piercing tip of the piercing element.

[0023] In one embodiment, in the proximal position the piercing tip extends a first predetermined distance relative to the distal end of the access cannula, and when the advancement mechanism is actuated the access cannula is advanced at least the first predetermined distance relative to the piercing element.

[0024] In one embodiment, the proximal end of the handle includes a rotary hub connected to the handle body, the rotary hub being secured to the access cannula, rotatable relative to the handle body and slidable relative to the handle a second predetermined distance.

[0025] In one embodiment, the cap is connected to the rotary hub and the connection automatically loads the advancement mechanism.

[0026] In one embodiment, the method further includes unloading the advancement mechanism by unlocking the cap from the rotary hub. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A distal aspect of an endoscopic access device in a piercing configuration is shown in accordance with various example embodiments described herein.

[0028] Figure 2 An enlarged view of a distal end of the endoscopic access device shown in Figure 1

[0029] Figure 3 A distal aspect of the endoscopic access device shown in Figure 1

[0030] Figure 4 A handle of the endoscopic access device of Figure 1 for controlling an access procedure in accordance with a first example embodiment.

[0031] Figure 5 An exploded view of a proximal end of the handle of Figure 4

[0032] Figures 6-13 Figure 4 ​​​​Views of the proximal end of the handle at different stages of assembly and deployment of the entry cannula advancement mechanism.

[0033] Figure 14 A method for loading and deploying the entry cannula advancement mechanism is shown.

[0034] Figure 15 A partial exploded view of the proximal end of the handle for controlling the entry process is shown according to a second exemplary embodiment.

[0035] Figure 16 A view of the proximal end of the handle is shown. Figure 15 A rotating hub of the proximal end of the handle is shown.

[0036] Figure 17 A view of the proximal end of the handle is shown. Figure 15 A tip cap of the proximal end of the handle is shown.

[0037] Figure 18a A view of the entry cannula advancement mechanism is shown in an initial piercing configuration. Figure 1 A distal end of the endoscopic entry device is shown.

[0038] Figure 18b A view of the entry cannula advancement mechanism is shown in a post-piercing configuration. Figure 1 A distal end of the endoscopic entry device is shown. DETAILED DESCRIPTION

[0039] The present disclosure can be understood with reference to the following description and drawings in which like elements are referred to with the same reference numerals. Exemplary embodiments describe an endoscopic entry device having the following features: the entry cannula is advanced distally relative to the sharp piercing tip ("sharp") when the clinician is ready to remove the sharp, i.e., after the piercing is complete, to reduce the likelihood of under-penetration and failure to enter the piercing hole.

[0040] Figure 1 A distal aspect of an endoscopic entry device 100 according to various exemplary embodiments described herein is shown. The entry device 100 includes an entry cannula 102 having a flexible distal tip 104 that is biased to assume a J-shape (J-shaped tip) when unconstrained. A sharp 106 (i.e., a piercing element) having a pointed end is advanced through the lumen of the entry cannula 102 such that the flexible J-shaped tip 104 is straightened via the rigidity of the sharp 106 until the sharp 106 extends distally out the distal end of the J-shaped tip 104 to a predetermined distance such that the sharp 106 can be used to puncture a target tissue and the sharp 106 and J-shaped tip 104 can be advanced together into the target anatomy.

[0041] The distance 108 by which the distal tip of the sharp 106 protrudes distally beyond the distal end of the J-shaped tip 104 when the sharp 106 is inserted therein is referred to as the "setback", as shown in Figure 2The length of the sharp 106 and the length of the access cannula 102 are designed such that the setback 108 is the desired length for performing the initial puncture of the access procedure when the sharp 106 is fully inserted into the handle and the rotating hub 202 at the proximal end of the device 100 is in the proximal (loaded) position (to be explained in more detail below).

[0042] After advancing the J-tip 104 and the sharp 106 into the target anatomy as needed, the sharp 106 is withdrawn proximally from the J-tip 104, releasing the J-tip 104 to return to its curved J-shape, as shown in Figure 3 The guidewire can then be inserted through the lumen of the access cannula 102 and out the distal end of the J-tip 104 into the target anatomy in a desired direction determined based on the aiming of the curved tip of the J-tip 104. For example, prior to inserting the guidewire into the access cannula 102, the J-tip 104 can be rotated via the rotating hub 202 to point the distal opening of the J-tip 104 to a desired location within the target anatomy as will be appreciated by those skilled in the art.

[0043] In the case where the target anatomy is a bile duct, the J-tip 104 can be rotated such that the distal opening of the lumen of the access cannula 102 faces either upstream or downstream of the bile duct toward the bile duct outlet into the small intestine. When the J-tip 104 is oriented as desired, the guidewire is threaded through the access cannula 102 to exit the opening at the distal end of the J-tip 104 until it extends in the desired direction from the J-tip 104 along the bile duct for a desired value. At this point, a flexible electrosurgical sheath 110 having an electrosurgical tip 112 can be advanced over the access cannula 102 and the J-tip 104 to dilate a first hole through which the access cannula 102 exits the small intestine and a second hole through which the access cannula 102 enters the target bile duct. As will be appreciated by those skilled in the art, when the tip 112 is at and within the entrance of one or both of the first and second holes, the electrodes of the electrosurgical tip 112 can be activated to cut and widen the holes to facilitate access to the target anatomy for further procedures (e.g., placement of a stent to bypass an obstruction).

[0044] A sharp 106 is typically used to create an initial hole in the anatomy through which the wider diameter distal tip 104 of the access cannula 102 (J-tip) can be pushed, such that when the sharp 106 is removed, the J-tip 104 is securely inserted into the target location within the target anatomy through the puncture hole. However, various complications can arise when performing this procedure. For example, the physician viewing the puncture through ultrasound or fluoroscopy can not be able to discern the location of the tip of the access cannula 102. As a result, the access cannula 102 can not be inserted far enough into the anatomy to maintain access when the sharp 106 is removed. In another example, withdrawal of the sharp 106 can provide a proximal pulling force on the access cannula 102 that dislodges the J-tip 104 from the puncture hole.

[0045] Figure 4 A handle 200 of the endoscopic access device 100 for controlling the access procedure according to a first exemplary embodiment is shown. The proximal end of the handle 200 includes a rotation hub 202 and a removable sharp cover 204. The access cannula 102 of this embodiment is rigidly fixed to the rotation hub 202 and extends through the interior of the handle 200 and out of its distal end. The rotation hub 202 has a passage extending therethrough providing access from the proximal end of the rotation hub 202 to the lumen of the access cannula 102, particularly for insertion of the sharp 106 therein and extending through the length of the access cannula 102.

[0046] The sharp 106 of this embodiment is rigidly fixed to the sharp cover 204 such that distal advancement of the sharp cover 204 distally advances the sharp 106 relative to the access cannula 102 and proximal pulling of the sharp cover 204 proximally withdraws the sharp 106 relative to the access cannula 102. The sharp cover 204 is coupled to the proximal end of the handle 200 and the sharp 106 can extend to its most distal position when the sharp cover 204 is so coupled. When coupled, the sharp cover 204 is positioned radially about the rotation hub 202. The sharp cover 204 is removable from the handle 200 and the access cannula 102 when the sharp cover 204 is so coupled. Figure 4 is shown in a partially retracted position relative to the handle 200 and the access cannula 102. The proximal aspect of the handle 200 including the rotation hub 202 and the sharp cover 204 will be described in more detail below with respect to the access cannula advancement mechanism.

[0047] Handle 200 has a distal collar 206 that connects to a coupling at the proximal end of the endoscope shaft. Handle 200 includes a length adjuster 208 through which a user can adjust the length of handle 200 so that when connected to an endoscope, the length of electrosurgical sheath 110 will extend distally beyond the distal end of the endoscope by a desired distance (i.e., length adjustment can be used to achieve a desired extension of the device from the endoscope). Handle 200 also includes a puncture actuator 210 that is slidable on a base 214 of handle 200 so that when unlocked by a puncture actuator lock 212, access cannula 102 and sharp 106 are pushed distally out of electrosurgical sheath 110 so that J-shaped tip 104 and sharp 106 can penetrate target tissue to a desired depth.

[0048] Handle 200 also includes an electrosurgical sled 216 that is slidably mounted on puncture actuator 210, with sled 216 connected to electrosurgical sheath 110. Sheath 110 extends distally from sled 216 through handle 200 so that sheath 110 can be advanced distally from an initial proximal position on access cannula 102 to bring electrosurgical tip 112 at the distal end of sheath 110 into contact with target tissue so that the tissue can be treated by applying energy from tip 112 (e.g., cauterizing tissue around an opening formed through a gastrointestinal tract wall and an entrance into a target pancreaticobiliary lumen).

[0049] Handle 200 includes an end cap 220 and a generator connection 222 extending therefrom at which a power source can be coupled to device 100, specifically to electrosurgical sheath 110. Electrosurgical sled 216 is held in a desired position above puncture actuator 210 by an electrosurgical sled lock 218. Depressing sled lock 218 allows electrosurgical sled 216 to slide on puncture actuator 210.

[0050] Figure 5 An exploded view of the proximal end of handle 200 is shown, including an access cannula advancement mechanism to maintain the puncture depth of access cannula 102 during removal of sharp 106. Figures 6-13 Views of the proximal end of handle 200 are shown at different stages of assembly and deployment of the advancement mechanism. Handle 200 includes an end cap spring 264 and a rotation hub spring 262 for loading and deploying the advancement mechanism, as explained in more detail below.

[0051] End cap 220 has a distal end 226 that is connected to the proximal end of handle 200 and an open proximal end 224 for receiving a distal portion of rotation hub 202 therein. End cap 220 is cannulated so that rotation hub 202 and access cannula 102 can extend therethrough. Proximal end 224 of end cap 220 has two or more radially inwardly extending deformable tabs 228 that are configured to be deformed by a rotation hub 202 to secure rotation hub 202 in end cap 220. Figure 9It is seen more clearly that the grommet 260 is held in place within the end cap 220 when the proximal end of the handle 200 is assembled. The inner surface of the end cap 220 is sized to decrease in diameter from a larger diameter proximal portion to a reduced diameter distal portion, the reduction in size forming a seat 230 against which the end cap spring 264 is loaded, as will be further explained below.

[0052] The rotating hub 202 extends from a proximal end 232 that is connected to the sharp cap 204 to a distal end 234 that is in turn connected to the end cap 220. The rotating hub 202 includes a proximal portion 236 that is sized and shaped to be received within the distal portion 248 of the sharp cap 204. A first flange 238 having a flared conical shape extends distally from the proximal portion 236 for locking the sharp cap 204 thereto, as will be further explained below. A shaft 240 extends from the first flange 238 to a second flange 242, and a slotted distal portion 244 extends from the second flange 242 to the distal end 234 for locking the rotating hub 202 in a temporarily fixed position relative to the handle 200. The grooves of the distal portion 244 engage aspects of the interior of the handle 200 that provide resistance to rotation of the rotating hub 202, but can be overcome by sufficient force so that the rotating hub 202 can be incrementally rotated and temporarily locked in a position from which it is to be further rotated.

[0053] The sharp cap 204 has a proximal portion 246 that can be grasped by a surgical practitioner. The sharp 106 extends from the interior of the proximal portion 246 through a hollow distal portion 248 that extends over the proximal portion 236 of the rotating hub 202 when the sharp cap 204 is coupled to the proximal portion 236 of the rotating hub 202. A flange portion 254 having a larger diameter connects the proximal portion 246 and the distal portion 248, and two wings 250 are connected to the flange portion 254 for locking the sharp cap 204 to the rotating hub 202 and unlocking the sharp cap 204 from the rotating hub 202. The wings 250 extend from a proximal end to a distal end 256 and are attached to the flange portion 254 at an intermediate location thereon so that the proximal portion of each wing 250 can be depressed, i.e., pushed radially inward, to widen the distal portion. The distal portion of each wing 250 has a tab 252 that protrudes radially inward that locks over the first flange 238 of the rotating hub 202, as shown, to connect the sharp cap 204 to the rotating hub 202. Depressing the proximal end of the wings 250 widens the distal end to unlock the sharp cap 204 from the rotating hub 202, and simultaneously releases the rotating hub 202 to advance the J-shaped tip 104 over the distal end of the sharp 106 when the advancement mechanism is loaded. Figures 11-12

[0054] ​The advancement mechanism includes a washer 260 disposed around the shaft 240 of the rotating hub 202, i.e., between the first and second flanges 238, 242 and slidable relative thereto. A rotating hub spring 262 is also disposed between the first and second flanges 238, 242, specifically between the washer 260 and the second flange 242, such that the rotating hub spring 262 can be compressed by sliding the washer 260 distally on the shaft 260. An end cap spring 264 is positioned within the end cap 220 against the base 230. While the rotating hub spring 262 has a smaller diameter such that the rotating hub spring 262 is contained on the shaft 240 by the second flange 242, the end cap spring 264 has a larger diameter such that the second flange 242 can be inserted within the end cap spring 264 without interfering therewith. The end cap spring 264 can be compressed against the base 230 by the washer 260 in the following manner.

[0055] Figures 6-13 A view of the proximal end of the handle 200 is shown at different stages of assembly and deployment of the advancement mechanism. Figure 6 The arrangement of the washer 260 and the rotating hub spring 262 relative to the rotating hub 202 is shown, while Figure 7 The end cap spring 264 is shown arranged within the end cap 220 against the base 230. Figure 8 The rotating hub 202 is shown inserted into the end cap 220. Figure 9 A perspective view of the proximal end of the handle 200 is shown with the rotating hub 202 fully inserted into the end cap 220. The deformable tab 228 allows the washer 260 to be pressed into the end cap 220, but is shaped to retain the washer 260 within the end cap 220 even when a force is applied proximally to the washer 260, i.e., when the end cap spring 264 is compressed against the washer 260. Note that when the proximal end of the handle 200 is held in the orientation shown, the entry cannula advancement mechanism is not yet loaded. Figure 9 The entry cannula advancement mechanism is shown loaded and deployed in

[0056] Loading and deployment of the advancement mechanism is shown in Figures 10-13 and will be described using the method 300 shown in Figure 14 The advancement mechanism is loaded while coupling the sharps cap 204 to the rotating hub 202. In 305, the sharps 106 are introduced into the entry cannula 102 and advanced distally such that the sharps cap 204 is advanced distally onto the handle 200, specifically onto the rotating hub 202, until the distal end 256 of the wing 250 is adjacent to the washer 260, as shown in Figure 10 In this position, the distal tip of the sharps 106 is within the J-shaped tip 104, i.e., is not exposed distally of the J-shaped tip 104.

[0057] In 310, the sharps cap 204 is further advanced distally over the rotating hub 202 such that the distal end 256 of the wing 250 pushes the washer 260 distally, as shown in Figure 11The distal tip of the sharp 106 is pushed out into the distal end of the access cannula 102 so that the sharp 106 is available to puncture the target anatomy during the access procedure. This advancement also causes the tabs 252 on the wings 250 to pass over the first flange 238 of the rotating hub 202 to lock the sharp cover 204 with the rotating hub 202. The position of the tabs 252 on the wings 250 relative to the distal end 256 of the wings is configured so that the washer 260 is held a predetermined distance from the first flange 238 of the rotating hub 202. The pushing of the washer 260 compresses the rotating hub spring 262 (against the second flange 242 of the rotating hub 202) and the end cap spring 264 (against the base 230 of the end cap 220).

[0058] At 315, the sharp cover 204 is released, allowing the end cap spring 264 to push the washer 260 proximally back to its initial position against the tab 228 of the end cap 220, as shown in FIG. 4B. Figure 12 However, because of the locked configuration of the sharp cover 204 and the rotating hub 202, both the sharp cover 204 and the rotating hub 202 are pushed proximally by the end cap spring 264. In this state, the rotating hub spring 262 is compressed and loaded. The surgical physician can use the sharp 106 that protrudes from the access cannula 102 to perform the puncture of the target anatomy. When the target anatomy is accessed to a sufficient depth and the physician is ready to remove the sharp, the method proceeds to 320.

[0059] At 320, the proximal end of the wings 250 of the sharp cover 204 is depressed, i.e., pushed radially inward, to move the distal end 256 (more specifically, the tabs 252) of the wings 250 radially outward to release the sharp cover 204 from the rotating hub 202 and allow the rotating hub spring 262 to decompress. Because the washer 260 is in its proximal-most position, and because the spring 262 cannot push further proximally, the decompression of the spring 262 instead exerts a force to the second flange 242 of the rotating hub 202 and forces the rotating hub 202 to push distally relative to the sharp cover 204, as shown in FIG. 4C. Figure 13 This returns the sharp cover 204 and the rotating hub 202 to their initial positions, i.e., the positions shown in FIG. 4A. Figure 10

[0060] At this point, the J-shaped tip 104 of the access cannula 102 has been forced over the tip of the sharp 106 without changing the position of the sharp 106. This motion further secures the access cannula 102 to the puncture hole created by the sharp 106 during the access procedure. The sharp cover 204 is unlocked from the rotating hub 202, so the sharp cover 204 can be withdrawn proximally, thereby pulling the sharp 106 proximally. The J-shaped tip 104 reverts to its J-shaped configuration, and the sharp 106 is finally removed from the handle 200 so that the access cannula 102 is available for other aspects of the procedure, e.g., insertion of a guide wire. ​

[0061] Figure 15 A partially exploded view of the distal end of a handle 400 according to a second exemplary embodiment is shown. The handle 400 is substantially similar to the handle 200 described above, but with a rotating hub 402, a sharps cover 404, and an end cap 420 replacing the rotating hub 202, sharps cover 204, and end cap 220 described above. Figures 1-3 The access cannula 102, sharps 106, and electrosurgical sheath 110 described in can be used with the handle 400. The second embodiment includes a spring 470 that is loaded against the rotating hub 402 and can be released to urge the rotating hub 402 distally.

[0062] exist Figure 16 The rotating hub 402, shown in more detail in FIG, extends from a proximal end 426 to a distal end 428 and has a distal portion 430 that is slidably coupled to the inner surface of the end cap 420. The distal portion 430 is sized so that its diameter substantially corresponds to the diameter of the interior of the end cap 420, and in the absence of any applied force, the rotating hub 402 remains in a fixed position relative to the handle 400. However, the distal portion 430 and the end cap 420 are loosely enough fitted so that a rotational force on the rotating hub 402 allows the hub 402 to rotate relative to the handle 400 and translate into rotation of the access cannula 102 and its J-shaped tip 104.

[0063] The distal portion 430 of the rotating hub 402 can also slide longitudinally relative to the end cap 420, translating into longitudinal advancement or retraction of the access cannula 102 relative to the fixture components. The access cannula advancement mechanism for the handle 400, which will be explained in more detail below, slides the rotating hub 402 distally from an initial proximal position to a distal position while the sharps cover 404 remains in a fixed position, thereby advancing the access cannula 102 deeper into the target tissue past the sharps 106 during the access procedure, similar to the advancement mechanism described above for the handle 200. The advancement mechanism can be actuated just before releasing the sharps cover 404 from the handle 400 to withdraw the sharps 106.

[0064] The rotating hub 402 has a flange portion 432 having a diameter that is larger than the diameter of the distal portion 430, and therefore larger than the diameter of the inner surface of the end cap 420 where the distal portion 430 is coupled to the end cap 420, so that the flange 432 does not advance distally beyond the proximal end of the inner surface of the end cap 420. The middle portion 434 of the rotating hub 402 has two living hinges 436 that extend distally and radially outwardly from a first end 438 to a second end 440. The living hinges 436 are disposed on opposite sides of the middle portion 434.

[0065] When the rotating hub 402 is in its proximal (i.e., loaded) position, the second end 440 of the living hinge 436 abuts the proximal end of the end cap 420, thereby preventing distal movement of the rotating hub 402 relative thereto. The living hinge 436 is depressed to allow the pre-loaded single or dual spring 470 (as shown but omitted in Figure 15 Figure 16 the proximal portion 442 of the rotating hub 402 is received in the sharps cap 404.

[0066] The sharps cap 404, seen in greater detail in Figure 17 , is essentially hollow, having a cylindrical interior extending therethrough from a substantially closed proximal end 450 to an open distal end 452. The proximal end 450 has an aperture for the sharps sheath 454 to extend therethrough, the sharps sheath 454 being fixed to both the cap 404 and the sharps 106, and having a handle 456 proximate the proximal end of the sharps cap 404 for manual advancement and retraction of the sharps cap 404 and the sharps 106 rigidly fixed relative to the securement assembly. The sharps cap 404 slides over the rotating hub 402 to assemble the device in preparation for piercing a target tissue. In the assembled configuration, the distal end 452 is positioned over the living hinge 436 of the rotating hub 402.

[0067] The sharps cap 404 has a lock release 458 extending through its diameter and proximate its distal end 452. When the sharps cap 404 and the rotating hub 402 are assembled, the lock release 458 is positioned over the living hinge 436. Depressing the lock release 458 causes its interior to depress the living hinge 436, causing the second end 440 of the hinge 436 to disengage contact with the end cap 420 and allow the rotating hub 402 to slide distally relative thereto.

[0068] The rotating hub 402 has a spring 470 connected to the flange 432 and loaded against the sharps cap 404 when the components are assembled. When the lock release 458 is depressed, the hinge 436 is depressed and the spring 470 is allowed to unload and advance the rotating hub 402 distally relative to the sharps 106, which remains in a fixed position, and into the cannula 102 a predetermined distance. Thus, the distal J-shaped tip 104 is advanced over the sharps 106 and remains into the target anatomy upon subsequent removal of the sharps 106.

[0069] Figure 18a A distal end of the device is shown according to the first or second embodiment when the device is in a loaded position and the sharps 106 extend in a piercing configuration. Figure 18b A distal end of the device is shown according to the first or second embodiment when the device is in an unloaded position and the cannula is advanced over the distal tip of the sharps 106.

[0070] ​In a third embodiment, the device handle includes a sliding component that can be manually advanced to bring the access cannula over the sharp tip prior to sharp removal, rather than using an automatic spring-loaded advancement mechanism as described above. The sliding component can be rigidly fixed to the rotating hub, such that longitudinal sliding of the sliding component also moves the rotating hub longitudinally relative to the sharp. The sliding component can be slidable between a proximal position in which the sharp is exposed for puncture, and a distal position in which the sharp is covered. The sliding component is retained in either of the two positions by friction or a snap.

[0071] In a fourth embodiment, the device handle includes a rack and pinion device. The handle includes a rack connected to the access cannula. A pinion is connected to the rack and has a shaft extending through its center and through both sides of the handle, with a position fixed to the shaft but allowed to rotate relative thereto. An advancement hub is located at one of the two ends of the shaft, and turning the advancement hub rotates the pinion, which engages the rack and advances the access cannula proximally or distally depending on the direction of rotation.

[0072] In a fifth embodiment, a dual position lever attached to the rotating hub is used to implement the distal / proximal motion described in the previous embodiments.

[0073] Those skilled in the art will appreciate that changes can be made to the above-described embodiments without departing from the inventive concept thereof. It will also be appreciated that structural features and methods associated with one of the embodiments can be incorporated into other embodiments. It is therefore understood that the application is not limited to the particular embodiments disclosed, but is capable of modification by those skilled in the art without departing from the scope of the present application as defined by the appended claims.

Claims

1. A device for accessing the pancreaticobiliary tree, comprising: an access cannula including a lumen extending therethrough, the access cannula being sized and shaped to extend through the endoscope shaft to target tissue within a living body; a puncture element sized and shaped to extend through the lumen of the access cannula and project distally from the distal end of the access cannula; and a handle comprising a handle body and an advancement mechanism for advancing the access cannula from a proximal position relative to the puncture element, wherein the puncture tip of the puncture element is exposed distal to the distal end of the access cannula, to a distal position relative to the puncture element, wherein the distal end of the access cannula covers the puncture tip of the puncture element; a rotating hub fixed to the access cannula and connected to a proximal end of the handle body, the rotating hub being rotatable relative to the handle body and slidable a second predetermined distance relative to the handle body; and a cap secured to the puncturing element and coupleable to the rotating hub, wherein the puncturing tip extends a first predetermined distance relative to the distal end of the access cannula when the cap and the rotating hub are coupled; wherein the proximal end of the handle includes an end cap into which the distal portion of the rotating hub is inserted to connect the rotating hub to the handle, the end cap having a base against which the first spring is positioned; and The rotating hub includes a first proximal flange and a second distal flange with a shaft extending therebetween, the shaft having a washer and a second spring slidable thereon and constrained between the first proximal flange and the second distal flange.

2. The device according to claim 1, wherein In the proximal position, the puncture tip extends a first predetermined distance relative to the distal end of the access cannula, and when the advancement mechanism is actuated, the access cannula is advanced relative to the puncture element by at least the first predetermined distance.

3. The device according to claim 1, wherein The end cap further includes a deformable tab at a proximal end thereof that allows the gasket to be inserted therein and prevents the gasket from being retracted therefrom, such that when the rotating hub is inserted into the end cap, the gasket is positioned against the first spring at a distal end and against the deformable tab at a proximal end.

4. The device according to claim 3, characterized in that The cover has a distal portion sized and shaped to cover a proximal portion of the rotating hub and two wings attached thereto, each wing having a tab extending radially inward from a distal end of the wing.

5. The device according to claim 4, wherein When the cover is advanced on the rotating hub, the tabs extending from the wings lock onto the first proximal flange of the rotating hub, securing the cover and the rotating hub to each other, wherein depressing the proximal portion of the wing extends the distal end of the wing, unlocking the wing from the first proximal flange.

6. The device according to claim 5, characterized in that The advancement mechanism is loaded by locking the wings against the first proximal flange, thereby pushing the washer into the end cap a third predetermined distance and compressing the first and second springs, and then releasing the cap to allow the first spring to push the washer back proximally a third distance against the deformable tab and the rotating hub while the second spring remains compressed between the washer and the second distal flange.

7. The device according to claim 6, wherein The loaded advancement mechanism is unloaded by unlocking the wings from the first proximal flange, causing the second spring to push the second distal flange of the rotating hub distally relative to the cover.

8. The apparatus according to claim 1, further comprising: The cap is connected to the rotating hub at the proximal end of the handle to automatically load the advancement mechanism.

9. The device according to claim 8, wherein The propulsion mechanism is unloaded by unlocking the cover from the rotating hub.

10. The apparatus according to claim 1, further comprising: The rotating hub has a living hinge that resists longitudinal movement of the rotating hub relative to the handle body in an extended position and can be depressed to a depressed position by a mechanism in the cover so that the rotating hub can move longitudinally relative to the handle body.

11. The apparatus of claim 10, further comprising: A spring is loaded against the rotating hub when the living hinge is in an extended position, wherein depressing the living hinge unloads the spring and moves the rotating hub a predetermined distance relative to the handle body.

12. A system for accessing the pancreaticobiliary tree, comprising: an endoscope comprising an endoscope shaft; an access cannula including a lumen extending therethrough, the access cannula being sized and shaped to extend through the endoscope shaft to a target tissue in vivo; a puncture element sized and shaped to extend through the lumen of the access cannula and project distally from the distal end of the access cannula; and a handle comprising a handle body, a rotating hub secured to the access cannula, and a cap secured to the puncturing element, the handle including a mechanism for advancing the rotating hub from a proximal position to a distal position relative to the handle body while the cap remains substantially stationary relative to the handle body; a rotating hub fixed to the access cannula and connected to a proximal end of the handle body, the rotating hub being rotatable relative to the handle body and slidable a second predetermined distance relative to the handle body; and a cap secured to the puncture element and coupleable to the rotating hub, wherein the puncture tip of the puncture element extends a first predetermined distance relative to the distal end of the access cannula when the cap and the rotating hub are coupled, wherein the proximal end of the handle includes an end cap into which the distal portion of the rotating hub is inserted to connect the rotating hub to the handle, the end cap having a base against which the first spring is positioned; and The rotating hub includes a first proximal flange and a second distal flange with a shaft extending therebetween, the shaft having a washer and a second spring slidable thereon and constrained between the first proximal flange and the second distal flange.

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