Device, system, and method for access cannula advancement

Abstract

To provide an access device, a system and a method for accessing an ultrasonic endoscope inspection (EUS) anatomy (for example, the pancreaticobiliary duct).SOLUTION: A device includes an access cannula 102, a puncturing element, and a handle 110. The access cannula 102 includes a lumen extending therethrough. The access cannula 102 is sized and shaped to extend through an endoscopic shaft to a target tissue within a living body. The puncturing element is sized and shaped to extend through the lumen of the access cannula 102 and exit a distal end of the access cannula 102. The handle 110 includes a handle body and a mechanism for advancing the access cannula 102 from a proximal position relative to the puncturing element, where a puncturing tip 106 of the puncturing element is exposed distal to a distal end of the access cannula 102, to a distal position relative to the puncturing element, where the distal end of the access cannula 102 covers the puncturing tip 106 of the puncturing element.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an endoscopic ultrasound (EUS) access device, system, and method for accessing an anatomical structure (e.g., the pancreaticobiliary duct).

Background Art

[0002] Endoscopic ultrasound (EUS) access procedures, in other words, access procedures that work under ultrasonic guidance, can be used to access anatomical structures such as the pancreaticobiliary duct or the liver. For example, pancreaticobiliary access procedures, such as procedures for inserting a stent and traversing an occlusion to penetrate the bile duct, may differ from other types of access procedures when the target biological structure is extremely small. Many EUS access devices cannot be adequately operated in such procedures, and even when they can be adequately operated, they may be exposed to multiple other difficulties. For example, a long, thin, sharp portion can easily create an initial puncture hole, but if it is too sharp, there is a risk that the sharp portion will penetrate through the entire thickness of the bile duct and exit outside the duct into non-target tissue, creating an unwanted opening in the bile duct.

[0003] Furthermore, if the access cannula is not inserted deep enough into the anatomical structure before the sharp portion is withdrawn, the access cannula can be left outside the structure after the sharp portion is withdrawn. Therefore, it is important for the clinician to reach the exact depth of the puncture. Since it is difficult for the clinician to identify the transition point between the sharp portion and the access cannula to confirm that the access cannula has been inserted to the exact depth of the structure according to EUS and / or fluoroscopy, it is sometimes difficult for the clinician to evaluate the depth of penetration.

Summary of the Invention

[0004] The present disclosure relates to a device including an access cannula, a piercing element, and a handle. The access cannula includes a lumen extending therethrough. The access cannula is sized and shaped to extend through an endoscopic shaft to a target tissue within a living body. The piercing element is sized and shaped to extend distally through the lumen of the access cannula to outside the distal end of the access cannula. The handle includes a handle body and a mechanism for advancing the access cannula from a proximal position relative to the piercing element, where a piercing tip of the piercing element is exposed distally beyond the distal end of the access cannula, to a distal position relative to the piercing element, where the distal end of the access cannula protects the piercing tip of the piercing element.

[0005] In an embodiment, at the proximal position, the piercing tip extends a first predetermined distance relative to the distal end of the access cannula, and when the advancing mechanism is actuated, the access cannula advances at least the first predetermined distance relative to the piercing element.

[0006] In an embodiment, the device further includes a rotary hub fixed to the access cannula and coupled to a proximal end of the handle body, the rotary hub being rotatable relative to the handle body and slidable relative to the handle body by a second predetermined distance, and a cap fixed to the piercing element and connectable to the rotary hub, wherein when the cap and the rotary hub are connected, the piercing tip extends the first predetermined distance relative to the distal end of the access cannula.

[0007] In an embodiment, the proximal end of the handle includes an end cap into which a distal portion of the rotary hub is inserted to couple the rotary hub to the handle, the end cap having a pedestal on which a first spring is disposed.

[0008] In an embodiment, the rotating hub includes a first proximal flange and a second distal flange, the second distal flange includes a shaft extending between the first proximal flange and the second distal flange, and the shaft has a washer and a second spring that is slidable thereon and constrained between the first and second flanges.

[0009] In an embodiment, the end cap further includes, at its proximal end, a deformable tab that allows insertion of the washer therein and resists pulling the washer out therefrom. When the rotating hub is inserted into the end cap, the washer is disposed against the first spring at the distal end and the deformable tab at the proximal end.

[0010] In an embodiment, the cap has a distal portion sized and shaped to cover the proximal portion of the rotating hub, and two wings attached thereto, each wing having a tab that extends radially inwardly of the distal end of the wing.

[0011] In an embodiment, when the cap is advanced over the rotating hub, the tab extending from the wing locks the first flange of the rotating hub, thereby fixing the cap and the rotating hub to each other. By expanding the distal end by pressing the proximal portion of the wing, the wing is released from the first flange.

[0012] In an embodiment, the advancing mechanism locks the wing to the first flange, thereby pushing the washer into the end cap by a third predetermined distance, compressing the first and second springs, and releasing the cap. In this state where the second spring remains compressed between the washer and the second flange, the first spring pushes the washer back proximally by a third distance against the deformable tab and the rotating hub, thereby loading the advancing mechanism.

[0013] In an embodiment, the loaded advancing mechanism is removed by releasing the wing from the first flange and forcibly moving the second flange of the rotary hub distally relative to the cap by the second spring.

[0014] In an embodiment, the device further includes a cap fixed to the piercing element and a rotary hub fixed to the access cannula. By connecting the cap to the rotary hub at the proximal end of the handle, the advancing mechanism is automatically loaded.

[0015] In an embodiment, the advancing mechanism is removed by releasing the cap from the rotary hub.

[0016] In an embodiment, the device further includes a cap fixed to the piercing element and a rotary hub fixed to the access cannula. The rotary hub has a living hinge that resists longitudinal movement of the rotary hub relative to the handle body in an extended position, and the living hinge can be pressed to a pressed position by a mechanism of the cap, whereby the rotary hub can move longitudinally relative to the handle body.

[0017] In an embodiment, when the living hinge is in the extended position, the device further includes a spring loaded against the rotary hub, and upon pressing of the living hinge, the spring is released to move the rotary hub a predetermined distance relative to the handle body. The present disclosure also relates to a device including an access cannula that includes a lumen extending therethrough, the access cannula being sized and shaped to extend through an endoscope shaft to a target tissue within a living body, a piercing element sized and shaped to extend distally out of a distal end of the access cannula through the lumen of the access cannula, a handle having a handle body, a rotary hub fixed to the access cannula, and a cap fixed to the piercing element, the handle including a mechanism for advancing the rotary 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.

[0018] The present disclosure also relates to a system including an endoscope including an endoscope shaft and an access cannula that includes a lumen extending therethrough, the access cannula being sized and shaped to extend through the endoscope shaft to a target tissue within a living body, a piercing element sized and shaped to extend distally out of a distal end of the access cannula through the lumen of the access cannula, a handle including a handle body, a rotary hub fixed to the access cannula, and a cap fixed to the piercing element, the handle including a mechanism for advancing the rotary 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.

[0019] Furthermore, the present invention relates 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 the puncture element through the lumen of the access cannula such that a puncture tip of the puncture element extends distally outside a distal end of the access cannula and a cap is fixed to a proximal end of the puncture 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 of the puncture element where the puncture tip is exposed distally of the distal end of the access cannula to a distal position of the puncture element where the distal end of the access cannula covers the puncture tip of the puncture element.

[0020] In an embodiment, at the proximal position, the puncture tip extends a first predetermined distance relative to the distal end of the access cannula, and when the advancing mechanism is actuated, the access cannula advances at least the first predetermined distance relative to the puncture element.

[0021] In an embodiment, the proximal end of the handle includes a rotary hub connected to a handle body, and the rotary hub fixed to the access cannula is rotatable relative to the handle body and slidable a second predetermined distance relative to the handle.

[0022] In an embodiment, the cap is connected to the rotary hub, and by this connection, the advancing mechanism is automatically loaded.

[0023] In an embodiment, the method further includes removing the advancing mechanism by releasing the cap from the rotary hub. BRIEF DESCRIPTION OF THE DRAWINGS

[0024]

Figure 1

[0025]

Figure 2

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Figure 3

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Figure 4

[0028]

Figure 5

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Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

[0030]

Figure 14

[0031]

Figure 15

[0032]

Figure 16

[0033]

Figure 17

[0034]

Figure 18a

[0035]

Figure 18b

DETAILED DESCRIPTION OF THE INVENTION

[0036] The present disclosure will be understood by reference to the following description and the accompanying drawings, and like elements are denoted by the same reference numerals. In the exemplary embodiments, to reduce the possibility of improper puncture depth and loss of access to the puncture hole, when the clinician is preparing to withdraw the sharp puncture tip (the "sharp tip"), i.e., after the puncture is complete, an endoscope access device is described that has features for advancing an access cannula distally relative to the sharp tip.

[0037] Figure 1 shows a distal aspect of the endoscopic access device 100 in accordance with various exemplary embodiments described in this patent specification. The access device 100 includes an access cannula 102 having a flexible distal tip 104 that is biased to assume a J-shaped configuration (J-tip) when unconstrained. A sharp tip 106 having a pointed tip (i.e., a piercing element) travels through the lumen of the access cannula 102 until the sharp tip 106 extends distally outwardly beyond the distal end of the J-tip 104 by a predetermined distance. Thus, the flexible J-tip 104 is straightened by the rigidity of the sharp tip 106, whereby the sharp tip 106 is used for piercing the target tissue, and the sharp tip 106 and the J-tip 104 can travel together into the target biological structure.

[0038] When the sharp tip 106 is inserted therein, the distance 108 by which the distal tip of the sharp tip 106 projects distally beyond the distal end of the J-tip 104 is shown as a "setback" as shown in Figure 2. As will be described in further detail below, the lengths of the sharp tip 106 and the access cannula 102 are designed such that the setback 108 is a desirable length for performing the first puncture of the access procedure when the sharp tip 106 is fully inserted into the handle and the rotary hub 202 at the proximal end of the device 100 is in the proximal position (loaded).

[0039] After the J-tip 104 and the sharp tip 106 have traveled into the desired target biological structure, as shown in Figure 3, the sharp tip 106 is withdrawn proximally outwardly from the J-tip 104, freeing the J-tip 104 to return to its curved J-shaped configuration. A guide wire is inserted into the lumen of the access cannula 102 and exits outwardly from the distal end of the J-tip 104 and into the target biological structure along a desired direction determined based on the aiming of the curved end of the J-tip 104. For example, the J-tip 104 can be rotated by the rotary hub 202 to orient the distal opening of the J-tip 104 in a desired direction within the target biological structure, as will be understood by those skilled in the art, prior to insertion of the guide wire into the access cannula 102.

[0040] When the target biological structure is the bile duct, the J-shaped tip 104 may rotate, whereby the distal opening of the lumen of the access cannula 102 faces either upstream of the bile duct or downstream toward the outlet of the bile duct in the small intestine. When the J-shaped tip 104 is oriented as desired, the guide wire is passed through the access cannula 102 until it extends out of the distal end opening of the J-shaped tip 104 in the desired direction along the bile duct. At this point, the flexible electrosurgical sheath 110 together with the electrosurgical chip 112 can travel over the access cannula 102 and the J-shaped tip 104, the access cannula 102 widens the first hole as it exits the small intestine, and the access cannula 102 widens the second hole as it enters the target bile duct. As will be understood by those skilled in the art, the electrodes of the electrosurgical chip 112 can be activated when the chip is in or entering either or both of the first and second holes to open and widen the holes for smooth access to the target biological structure for further procedures (e.g., placing a stent to bypass an occlusion).

[0041] A sharp tip 106 is typically used to form a starting hole in the biological structure through which the wide-diameter distal tip 104 (J-shaped tip) of the access cannula 102 is pushed, such that when the sharp tip 106 is removed, the J-shaped tip 104 is firmly inserted through the puncture hole to the target position within the target biological structure. However, various complex situations can occur during the performance of this operation. For example, when the doctor views the puncture by ultrasound or fluoroscopy, the location of the tip of the access cannula 102 cannot be determined. As a result, the access cannula 102 may not be inserted deep enough into the biological structure to maintain access when the sharp tip 106 is removed. In another example, withdrawal of the sharp tip 106 can pull the access cannula 102 proximally, releasing the J-shaped tip 104 from the puncture hole.

[0042] Figure 4 shows the handle 200 of the endoscope access device 100 for controlling the access procedure according to the first exemplary embodiment. The proximal end of the handle 200 includes a rotary hub 202 and a removable sharp cap 204. The access cannula 102 of this embodiment is firmly fixed to the rotary hub 202 and extends through the interior of the handle 200 to the outside of its distal end. The rotary hub 202 has a channel that extends therethrough and provides access from the proximal end of the rotary hub 202 to the lumen of the access cannula 102, and is provided in particular for the sharp tip 106 that should be inserted therein and extend along the length of the access cannula 102.

[0043] The sharp tip 106 of this embodiment is firmly fixed to the sharp cap 204, whereby advancing the sharp cap 204 distally advances the sharp tip 106 distally relative to the access cannula 102, and pulling the sharp cap 204 proximally pulls the sharp tip 106 proximally relative to the access cannula 102. The sharp cap 204 is connected to the proximal end of the handle 200, and when the sharp cap 204 is connected, the sharp tip 106 can be extended to its most distal position. When connected, the sharp cap 204 is radially arranged around the rotary hub 202. The sharp cap 204 is shown in FIG. 4 in a partially withdrawn position relative to the handle 200 and the access cannula 102. The proximal aspect of the handle 200 including the rotary hub 202 and the sharp cap 204 will be described in more detail below with respect to the access cannula advancement mechanism.

[0044] The handle 200 has a distal collar 206 that is attached to a coupling at the proximal end of the endoscope shaft. The handle 200 includes a length adjustment section 208 such that when connected to the endoscope, the user can adjust the length of the handle 200, whereby the length of the electrosurgical sheath 110 extends distally beyond the distal end of the endoscope by a desired distance. (That is, the length adjustment section can be used to achieve a desired extension of the device outwardly of the endoscope). The handle 200 further includes a piercing actuator 210 that is slidable over the base 214 of the handle 200 and, when released by a piercing actuator lock 212, the access cannula 102 and the sharp tip 106 advance distally outwardly of the electrosurgical sheath 110, whereby the J-shaped tip 104 and the sharp tip 106 can penetrate the target tissue to a desired depth.

[0045] The handle 200 further includes an electrosurgical thread 216 that is slidably mounted over the piercing actuator 210 and the thread 216 is connected to the electrosurgical sheath 110. The sheath 110 extends distally from the thread 216 through the handle 200, whereby the sheath 110 advances distally from an initial proximal position over the access cannula 102 and contacts the electrosurgical tip 112 with the target tissue at the distal end of the sheath 110, whereby the tissue can be treated by application of energy from the tip 112. (For example, cauterizing around an opening formed through the wall of the gastrointestinal tract and an opening into the target pancreaticobiliary lumen).

[0046] The handle 200 includes a power connection 222 extending therefrom and a source of electrical energy can be connected to the device 100, specifically, to the electrosurgical sheath 110 and the end cap 220. The electrosurgical thread 216 is maintained at a desired position on the piercing actuator 210 by an electrosurgical thread lock 218. Pressing the thread lock 218 enables the electrosurgical thread 216 to slide over the piercing actuator 210.

[0047] FIG. 5 shows an exploded view of the proximal end of handle 200 including an access cannula advancement mechanism that maintains the depth of penetration for access cannula 102 during removal of the sharp tip 106. FIGS. 6 - 13 show views of the proximal end of handle 200 at various stages of assembly and placement of the advancement mechanism. Handle 200 includes an end cap spring 264 and a rotary hub spring 262 for loading and placement of the advancement mechanism, which will be described in more detail below.

[0048] End cap 220 has a distal end 226 that couples to the proximal end of handle 200 and a proximal end 224 of the opening for receiving the distal portion of rotary hub 202 therein. End cap 220 is inserted with the cannula such that rotary hub 202 and access cannula 102 may extend therethrough. The proximal end 224 of end cap 220 has two or more deformable tabs 228 that radially extend inwardly and hold washer 260 in place within end cap 220 as seen more clearly in FIG. 9 when the proximal end of handle 200 is assembled. The inner surface of end cap 220 decreases in size from a large diameter proximal portion to a small diameter distal portion, and the decrease in size forms a pedestal 230 into which end cap spring 264 is loaded, which will be further described below.

[0049] The rotating hub 202 extends from a proximal end 232 that connects to the sharp cap 204 and thus to a distal end 234 that connects to the end cap 220. The rotating hub 202 includes a proximal portion 236 having an outer diameter sized and shaped to be received within a distal portion 248 of the sharp cap 204. A first flange 238 having a flared conical shape extends distally from the proximal portion 236 to lock the sharp cap 204 thereto, as further described below. A shaft 240 extends from the first flange 238 to a second flange 242, and a grooved distal portion 244 extends from the second flange 242 to the distal end 234 to lock the rotating hub 202 in a position temporarily fixed relative to the handle 200. The plurality of grooves in the distal portion 244 engage aspects inside the handle 200 that resist rotation of the rotating hub 202, but can be overcome by sufficient force such that the rotating hub 202 may begin to rotate gradually and may remain temporarily locked in a position holding further rotation in reserve.

[0050] The sharp cap 204 has a proximal portion 246 that can be grasped by the operating physician. The sharp tip 106 extends from inside the proximal portion 246 through a hollow distal portion 248 that extends onto the proximal portion 236 of the rotary hub when the sharp cap 204 is connected to the rotary hub. A flange portion 254 having a large diameter connects the proximal portion 246 and the distal portion 248, and two wings 250 are connected to the flange portion 254 to lock the sharp cap 204 to the rotary hub 202 and to release the sharp cap 204 from the rotary hub 202. The wings 250 extend from a proximal end to a distal end 256 and are attached to the flange portion 254 at a central position thereon, whereby the proximal portions of the respective wings 250 are pressed, i.e., pushed radially inward, to spread the distal portions. The distal portions of the respective wings 250 have protrusions 252 that project radially inward and lock onto the first flange 238 of the rotary hub 202 to connect the sharp cap 204 to the rotary hub 202, as seen in FIGS. 11 and 12. When the advancing mechanism is loaded, by pressing the proximal ends of the wings 250 to spread the distal ends, the sharp cap 204 is released from the rotary hub 202, and at the same time, the rotary hub 202 is released to advance the J-shaped tip 104 at the distal end of the sharp tip 106.

[0051] The advancing mechanism includes a washer 260 disposed around the shaft 240 of the rotary hub 202, i.e., slidable therebetween with respect to the first flange 238 and the second flange 242. The rotary hub spring 262 is also disposed between the first flange 238 and the second flange 242, specifically, between the washer 260 and the second flange 242, whereby the rotary hub spring 262 can be compressed by sliding the washer 260 distally thereon along the shaft 260. The end cap spring 264 is disposed inside the end cap 220 with respect to the pedestal 230. The rotary hub spring 262 has a small diameter, whereby the rotary hub spring 262 is held on the shaft 240 by the second flange 242, while the end cap spring 264 has a large diameter, whereby the second flange 242 can be inserted into the end cap spring 264 without interfering therewith. The end cap spring 264 can be compressed by the washer 260 with respect to the pedestal 230, as will be described below.

[0052] Figures 6 - 13 show views of the proximal end of the handle 200 at various stages of assembly and placement of the advancing mechanism. Figure 6 shows the placement of the washer 260 and the rotary hub spring 262 with respect to the rotary hub 202, while Figure 7 shows the end cap spring 264 disposed inside the end cap 220 with respect to the pedestal 230. Figure 8 shows the rotary hub 202 inserted into the end cap 220. Figure 9 shows a perspective view of the proximal end of the handle 200 having the rotary 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 hold the washer 260 within the end cap 220 even when a proximal force is applied to the washer 260, i.e., when the end cap spring 264 is compressed against the washer 260. Note that the access cannula advancing mechanism is not yet loaded when the proximal end of the handle 200 is positioned as shown in Figure 9.

[0053] The loading and placement of the advancement mechanism are shown in FIGS. 10-13 and are described with Method 300 shown in FIG. 14. The advancement mechanism is loaded simultaneously with the connection of the sharp cap 204 to the rotating hub 202. As shown in FIG. 10, at 305, the sharp tip 106 is introduced into and advanced distally within the access cannula 102 until the distal end 256 of the wing 250 is adjacent to the washer 260, whereby the sharp cap 204 advances distally over the handle 200, specifically, over the rotating hub 202. At this position, the distal tip of the sharp tip 106 is present within the J-shaped tip 104, i.e., not exposed distally of the J-shaped tip 104.

[0054] At 310, the sharp tip cap 204 is pushed further distally over the rotating hub 202, whereby, as shown in FIG. 11, the distal end 256 of the wing 250 pushes the washer 260 distally. Several operations occur simultaneously during this step. The advancement of the sharp cap 204 relative to the rotating hub 202 pushes the distal tip of the sharp tip 106 out of the distal end of the access cannula 102, whereby the sharp tip 106 can be used to puncture the target biological structure during the access procedure. Further, due to this advancement, the protrusion 252 on the wing 250 is moved beyond the first flange 238 of the rotating hub 202 to lock the sharp cap 204 by the rotating hub 202. The position of the protrusion 252 on the wing 250 is set relative to the distal end 256 of the wing, whereby the washer 260 is held at a predetermined distance from the first flange 238 of the rotating hub 202. Due to the pressing of the washer 260, both the rotating hub spring 262 (relative to the second flange of the rotating hub 202) and the end cap spring 264 (relative to the pedestal 230 of the end cap 220) are compressed.

[0055] At 315, the sharp cap 204 is released, allowing the end cap spring 264 to push the washer 260 proximally back to its initial position relative to the tab 228 of the end cap 220, as shown in FIG. 12. However, due to the locked configuration of the sharp cap 204 and the rotary hub 202, both the sharp cap 204 and the rotary hub 202 are pushed proximally by the end cap spring 264. In this state, the rotary hub spring 262 is compressed and loaded. The operating physician can perform a puncture of the target biological structure by using the sharp tip 106 extended outside the access cannula 102. When the target biological structure is accessed to the appropriate depth, the physician prepares to withdraw the tip and proceeds to method 320.

[0056] At 320, the proximal end of the wing 250 of the sharp cap 204 is pressed, i.e., pushed radially inward, to move the distal end 256 of the wing 250, and more specifically the protrusion 252, radially outward to release the sharp cap 204 from the rotary hub 202 and allow the restoration of the rotary hub spring 262. As shown in FIG. 13, since the washer 260 is in its most proximal position and is not further forced proximally by the force of the spring 262, the restoration of the spring 262 instead applies a force to the second flange 242 of the rotary hub 202, forcing the rotary hub 202 distally relative to the sharp cap 204. This returns the sharp cap 204 and the rotary hub 202 to their initial positions, i.e., the positions shown in FIG. 10.

[0057] At this point, the J-shaped tip 104 of the access cannula 102 is being forced to move beyond the tip of the sharp tip 106 without changing the position of the sharp tip 106. During the access procedure, this operation further seats the access cannula 102 in the puncture hole created by the sharp tip 106. The sharp cap 204 is released from the rotary hub 202, and as a result, the sharp tip 106 is retracted proximally and the sharp cap 204 can be pulled proximally. When the J-shaped tip 104 returns to its J-shaped configuration and the sharp tip 106 is finally removed from the handle 200, the access cannula 102 can then be used for further aspects of the procedure, such as the insertion of a guide wire.

[0058] According to a second exemplary embodiment, FIG. 15 shows a partially exploded view of a distal end portion of a handle 400. The handle 400 is substantially similar to the handle 200 described above, except that the rotary hub 202, sharp cap 204, and end cap 220 described above are replaced by a rotary hub 402, sharp cap 404, and end cap 420. The access cannula 102, sharp tip 106, and electrosurgical sheath 110 described in FIGS. 1-3 can be used with the handle 400. The second embodiment includes a spring 470 that is loaded against the rotary hub 402 and can be released to force the rotary hub 402 distally.

[0059] The rotary hub 402, seen in more detail in FIG. 16, 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 such that its diameter substantially corresponds to the diameter inside the end cap 420, and the rotary hub 402 is formed to remain in a fixed position relative to the handle 400 unless a force is applied. However, the distal portion 430 and the end cap 420 are loosely fitted, such that the rotational force of the rotary hub 402 allows rotation of the hub 402 relative to the handle 400 and is translated into rotation of the access cannula 102 and its J-shaped tip 104.

[0060] The distal portion 430 of the rotary hub 402 is also longitudinally slidable relative to the end cap 420 and is converted into longitudinal advancement or retraction of the access cannula 102 relative to the components of the stationary device. The access cannula advancement mechanism for the handle 400, which is described in more detail below, slides the rotary hub 402 distally from its initial proximal position to a distal position while the sharp cap 404 remains in a fixed position, such that, similar to the advancement mechanism for the handle 200 described above, during the access procedure the access cannula 102 advances deeper into the target tissue beyond the sharp tip 106. The advancement mechanism can be actuated immediately prior to releasing the sharp cap 404 from the handle 400 to withdraw the sharp tip 106.

[0061] The rotary hub 402 has a flange portion 432 having a diameter larger than the diameter of the distal portion 430 and larger than the diameter of the inner surface of the end cap 420 to which the distal portion 430 is connected, whereby the flange 432 cannot advance distally beyond the proximal end of the inner surface of the end cap 420. The intermediate portion 434 of the rotary hub 402 extends distally from a first end 438 to a second end 440 and has two living hinges 436 that extend radially outward. The living hinges 436 are disposed on both sides of the intermediate portion 434.

[0062] The rotary hub 402 prevents distal movement of the rotary hub 402 relative thereto when the second end 440 of the hinge 436 is in a proximal (i.e., loaded) position adjacent to the proximal end of the end cap 420. As described below, the living hinge 436, although removed in FIG. 16, is biased as shown in FIG. 15 by one or two springs 470 pre-loaded to allow the rotary hub 402 to advance to its distal (i.e., released) position. The proximal portion 442 of the rotary hub 402 is received by the sharp cap 404 when the components are connected.

[0063] As can be seen in more detail in FIG. 17, the sharp cap 404 is substantially hollow and has a cylindrical interior that extends therethrough from a substantially closed proximal end 450 to an open distal end 452. The proximal end 450 has a hole for the sharp sheath 454 to extend therethrough, and the sharp sheath 454 is fixed to the cap 404 and the sharp tip 106, and has a proximal end proximal to the sharp cap 404 having a grip 456 for manually advancing and retracting the sharp cap 404 and the firmly fixed sharp tip 106 relative to the components of the stationary device. In preparation for puncturing the target tissue, to assemble the device, the sharp cap 404 slides over the rotary hub 402. In the assembled configuration, the distal end 452 is disposed over the living hinge 436 of the rotary hub 402.

[0064] The sharp cap 404 has a lock release 458 that extends through a diameter adjacent to its distal end 452. When the sharp cap 404 and the rotary hub 402 are assembled, the lock release 458 is disposed over the living hinge 436. By pressing the lock release 458, its interior presses against the living hinge 436, moving the second end 440 of the hinge 436 away from contact with the end cap 420 and allowing the rotary hub 402 to slide distally relative thereto.

[0065] The rotary hub 402 has a spring 470 that is coupled to the flange 432 and loaded against the sharp cap 404 when the components are assembled. When the lock release 458 is pressed, the hinge 436 is pressed and the spring 470 allows the rotary hub 402 and the access cannula 102 to be released and advanced distally a predetermined distance relative to the sharp tip 106 that remains in a fixed position. As a result, the distal J-shaped tip 104 is pushed over the sharp tip 106 and maintains access to the target biological structure when the sharp tip 106 is later removed.

[0066] FIG. 18a shows the distal end of the device according to either the first or second embodiment in the loaded position, with the sharp tip 106 extended in the piercing configuration. FIG. 18b shows the distal end of the device according to either the first or second embodiment in the removed position, with the access cannula advancing beyond the distal tip of the sharp tip 106.

[0067] In the third embodiment, rather than using the automatic spring-loading advancing mechanism described above, the device handle includes a slidable component that can be manually advanced to carry the access cannula over the tip of the sharp tip before removal of the sharp tip. The slidable component may be firmly fixed to a rotating hub, whereby sliding the slidable component longitudinally also moves the rotating hub longitudinally relative to the sharp tip. The slidable component is slidable between a proximal position where the sharp tip is exposed for piercing and a distal position where the sharp tip is covered. The slidable component is held in either of the two positions by friction or a fastener.

[0068] In the fourth embodiment, the device handle includes an arrangement of a rack and a pinion gear. The handle includes a rack attached to the access cannula. The gear is connected to the rack and has a shaft that extends through the center and both sides of the handle, being positionally fixed but allowed to rotate relative thereto. The advancing hub is present at one of the two ends of the shaft, and rotation of the advancing hub causes the gear to rotate, which meshes with the rack and pushes the access cannula proximally or distally depending on the direction of rotation.

[0069] In the fifth embodiment, two-position levers attached to the rotating hub are used to effect the distal / proximal movement described in the previous embodiment.

[0070] It will be understood by those skilled in the art that changes may be made to the above-described embodiments without departing from the concept of the invention of the present application. Furthermore, it should be understood that structural features and methods relating to one embodiment may be incorporated into other embodiments. As a result, it is also understood that this invention is not limited to the specific embodiments disclosed, but rather that modifications are protected within the scope of the invention as defined by the appended claims.

Claims

1. an access cannula including a lumen extending therethrough, the access cannula sized and shaped to extend through an endoscope shaft to a target tissue within a living body; a piercing element sized and shaped to extend distally through the lumen of the access cannula and out of the distal end of the access cannula; a handle including a handle body and a mechanism for advancing the access cannula from a proximal position relative to the puncture element where a puncture tip of the puncture element is exposed distally from a distal end of the access cannula to a distal position relative to the puncture element where the distal end of the access cannula protects the puncture tip of the puncture element; a rotation hub secured to the access cannula and coupled to a proximal end of the handle body, the rotation hub being rotatable relative to the handle body and slidable a first predetermined distance relative to the handle body, the rotation hub including a proximal first flange and a distal second flange with a shaft extending therebetween, the shaft having a slidable washer and a slidable first spring, the first spring being captured between the washer and the second flange; An apparatus comprising:

2. 10. The device of claim 1, further comprising a cap secured to the puncture element and connectable to the rotation hub, the puncture tip extending a second predetermined distance relative to the distal end of the access cannula when the cap and the rotation hub are connected.

3. 3. The device of claim 2, wherein the cap further includes a deformable tab at a proximal end thereof that allows insertion of the washer therein and resists withdrawal of the washer therefrom, and wherein when the rotating hub is inserted into the cap, the washer is positioned against a second spring at a distal end and against the deformable tab at a proximal end.

4. 4. The device of claim 3, wherein the cap has a distal portion sized and shaped to cover a proximal portion of the rotation hub and two wings attached thereto, each wing having a tab extending radially inwardly from a distal end of the wing.

5. 5. The device of claim 4, wherein the tabs extending from the wings engage the first flange of the rotation hub, thereby securing the deformable tabs and the rotation hub to one another, and wherein the wings are released from the first flange by spreading the distal ends of the wings apart by compressing the proximal portions of the wings.

6. 6. The device of claim 5, wherein the mechanism locks the wing onto the first flange, thereby forcing the washer into the cap a third predetermined distance and compressing the first and second springs, and releasing the cap causes the first spring to push the washer back proximally against the cap and rotating hub a third predetermined distance while the second spring remains compressed between the washer and the second flange, thereby loading the mechanism.

7. 7. The device of claim 6, wherein the loaded mechanism is removed by releasing the wings from the first flange and forcing the second flange of the rotating hub distally relative to the cap with the second spring.

8. The device of claim 1 , further comprising a cap secured to the piercing element, the mechanism being automatically primed by coupling the cap to the rotation hub at the proximal end of the handle body.

9. a cap secured to the piercing element; 2. The device of claim 1, wherein the rotation hub has a living hinge that, in an extended position, resists longitudinal movement of the rotation hub relative to the handle body, the living hinge being pressable into a pressed position by a feature on the cap, thereby allowing the rotation hub to move longitudinally relative to the handle body.

10. 2. The device of claim 1, further comprising an end cap at the proximal end of the handle body into which a distal portion of the rotation hub is inserted to connect the rotation hub to the handle body, the end cap having a seat in which the first spring is positioned.

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