EUS access device with electrosurgery-enhanced puncture

Abstract

To provide endoscopic ultrasound (EUS) access devices for accessing anatomical structures e.g., the pancreatico-biliary tree.SOLUTION: Provided is a device including a catheter that includes a lumen extending therethrough, and that is sized and shaped to extend through an endoscopic shaft to a target tissue within a living body. The device also includes a puncturing device sized and shaped to extend through the lumen of the catheter and distally out a distal end of the catheter. The device further includes at least one of the catheter and the puncturing device including an electrode formed thereon. The electrode is energizable from a handle of the device when the puncturing device is extended distally out the distal end of the catheter. The electrode is energized when the device punctures the target tissue.SELECTED DRAWING: Figure 1a

Description

[Technical field]

[0001] The present invention relates to an endoscopic ultrasound (EUS) access device for accessing biological structures such as the pancreaticobiliary system. [Background technology]

[0002] Endoscopic ultrasound (EUS) access procedures are used, for example, under ultrasound guidance, to access anatomy such as the pancreaticobiliary system and pancreatic pseudocysts. Pancreaticobiliary access procedures, such as procedures to insert stents to bypass blockages, differ from other types of access procedures in that the target anatomy is quite narrow. Many EUS access devices have insufficient maneuverability for biliary procedures, and even if they have sufficient maneuverability, they may face other challenges. For example, devices with long, narrow sharps can easily form an initial puncture hole, but there is a risk that the sharps will overextend, for example, to the other side of the bile duct or other non-target tissue.

[0003] Additionally, if the access cannula is placed along the outer diameter of the sharp during the initial puncture, a long sharp may not be able to carry the access cannula distally within the puncture hole a sufficient distance to maintain access to the bile duct after the sharp is removed. Alternatively, a device with a thicker, shorter sharp may reduce the risk of an inadvertent puncture, but may make the initial puncture more difficult, for example, by increasing the force required to puncture the target tissue. In yet another example, a blunt access cannula may not be able to follow the sharp tip into the puncture hole. Summary of the Invention

[0004] The present invention relates to a device including a catheter including a lumen extending therethrough and configured to extend through an endoscope shaft to a target tissue within a living body, and a piercer configured to pass through the lumen of the catheter and extend distally from a distal end of the catheter, at least one of the catheter and the piercer including an electrode formed thereon, the electrode being capable of being energized from a handle of the device such that the electrode is energized as the device pierces the target tissue when the piercer extends distally from the distal end of the catheter.

[0005] In one embodiment, the distal end of the catheter is biased to assume a J-shaped curve when unconstrained. In one embodiment, the distal end is rotatable about the longitudinal axis of the catheter to direct the distal opening of the distal end in a desired direction within the target tissue.

[0006] In one embodiment, as the piercer pierces the target tissue, the distal end of the catheter follows the piercer into the target tissue. In one embodiment, the device further includes an electrosurgical sheath longitudinally slidable along the exterior of the catheter, the electrosurgical sheath having an electrosurgical tip for dilating an access hole formed by the puncture in the target tissue.

[0007] In one embodiment, the distal end of the catheter is straightened when the piercer extends into the distal end of the catheter. In one embodiment, the electrodes are formed at the distal end of the catheter.

[0008] In one embodiment, the proximal section of the catheter between the distal end of the catheter and the distal end of the handle is formed from a non-conductive material and further includes electrical leads connecting the electrodes to the handle. In one embodiment, the device further includes an electrode formed on the distal end of the piercer.

[0009] In one embodiment, the electrode is formed at the distal end of the piercer. In one embodiment, the device further includes an insulating layer extending along the piercer from the proximal end of the electrode to the proximal end of the piercer.

[0010] In one embodiment, the handle further includes a length adjustment section, a sharps hub, a puncture actuator for distally advancing the puncture tool and catheter out of a sheath of the device, an electrosurgical sled slidably mounted on the puncture actuator for advancing the sheath distally over the catheter to apply energy to the target tissue with electrodes formed on the sheath, a puncture actuator lock, an electrosurgical sled lock for locking the position of the sheath at a desired position relative to the catheter, and a first generator connection on the electrosurgical sled configured to connect to a source of electrical energy.

[0011] In one embodiment, the handle further includes at least one of a second generator connection provided on the puncture actuator configured to connect to a source of electrical energy and a third generator connection provided on the sharps hub configured to connect to a source of electrical energy.

[0012] The invention also relates to a system including a catheter including a lumen extending therethrough and sized and shaped to pass through an endoscope shaft to a target tissue in a living body; a piercer sized and shaped to pass through the lumen of the catheter and extend distally outwardly from a distal end of the catheter; at least one of the catheter and the piercer including an electrode formed thereon, the electrode being energizable from a handle of the device such that the electrode is energized as the device pierces the target tissue as the piercer extends distally outwardly from the distal end of the catheter; and an electrosurgical sheath longitudinally slidable along the outside of the catheter, the electrosurgical sheath having an electrosurgical tip for dilating an access hole formed by the piercer in the target tissue.

[0013] In one embodiment, the distal end is rotatable about the longitudinal axis of the catheter to direct the distal opening of the distal end in a desired direction within the target tissue. The present invention further relates to a method comprising the steps of extending a puncture tool through a lumen of a catheter, the catheter being sized and shaped to pass through an endoscope shaft and extend to a target tissue within a living body, at least one of the catheter and the puncture tool including an electrode formed thereon, extending the puncture tool through a lumen of the catheter, energizing the electrode, puncturing the target tissue with the puncture tool, advancing the catheter distally through an access hole formed by the puncture tool in the target tissue, and retracting the puncture tool proximally through the lumen past the distal end of the catheter.

[0014] In one embodiment, the method further comprises sliding an electrosurgical sheath over the outside of the catheter, the electrosurgical sheath having an electrosurgical tip, placing the electrosurgical tip in contact with tissue surrounding the access hole, and applying an electric current to dilate the access hole.

[0015] In one embodiment, the method further includes locking the electrosurgical sheath at a desired location relative to the catheter. In one embodiment, the method further includes rotating the distal end of the catheter about a longitudinal axis of the catheter to direct a distal opening of the distal end of the catheter in a desired direction within the target tissue.

[0016] In one embodiment, the electrode is formed on a distal end of the catheter. The method further includes energizing an electrode formed on the distal end of the piercer prior to piercing the target tissue with the piercer. [Brief description of the drawings]

[0017] [Figure 1a] 1 illustrates the distal end of an endoscopic access device. [Figure 1b]1 illustrates the distal end of an endoscopic access device. [Figure 2a] FIG. 1 illustrates an endoscopic access device with a long sharp tip. [Figure 2b] FIG. 1 illustrates an endoscopic access device with a short sharp tip. [Figure 2c] FIG. 13 shows an endoscopic access device with excessive misalignment between the sharp portion and the J-tip. [Diagram 3] FIG. 13 shows the distal tip of a microcatheter with an exposed metal end that can be energized for high temperature puncture in an EUS access procedure. [Figure 4] FIG. 13 illustrates a sharp with an exposed metal end that can be energized for high temperature puncture in an EUS access procedure. [Diagram 5] FIG. 1 illustrates a handle for controlling the EUS access procedure. [Figure 6] FIG. 1 illustrates a fine needle aspiration (FNA) needle with a blunt end that can be energized for high temperature puncture in an EUS access procedure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention may be further understood by reference to the following description and accompanying drawings, in which like elements are given the same reference numerals. An exemplary embodiment describes an EUS access device having a high temperature sharp and / or J-tip for effective puncture and J-tip placement with low puncture force and low risk of losing access to the target tissue. As used herein, the term "high temperature" refers to an element that is electrosurgically activated. When activated, the high temperature element is designed to pass electrical current through the target tissue while leaving the target tissue relatively unheated, such that the electrical resistance of the target tissue heats and boils the target tissue so that the target tissue is incised and dilated. As used herein, the term "low temperature" refers to an element that is not electrosurgically activated.

[0019] 1a-1b show an exemplary EUS access device 100 including a microcatheter 102 (i.e., access cannula) having a flexible distal tip 104 that assumes a J-shape (J-tip) in a normal position when unconstrained. A piercing element 106 having a pointed end (i.e., sharp) is advanced through the lumen of the microcatheter 102 such that the flexible J-tip 104 is straightened by the stiffness of the sharp 106 until the sharp 106 extends distally from the distal end of the J-tip a desired distance such that the sharp 106 can be used to pierce the target tissue so that the sharp 106 and J-tip 104 can be advanced together into the target anatomy.

[0020] When the sharp 106 is inserted into the J-tip 104, the distance 108 that the distal tip of the sharp 106 projects distally beyond the distal end of the J-tip 104 is referred to as the "setback." After the J-tip 104 and sharp 106 have been advanced as desired into the target anatomy, the sharp 106 is withdrawn proximally from the J-tip 104, releasing the J-tip 104 back to its curved J-shape, as shown in FIG. 1b. A guidewire is then inserted through the lumen of the microcatheter 102 and out the distal end of the J-tip 104 and into the target anatomy. Before, during, or after the guidewire is inserted into the microcatheter 102, the J-tip 104 may be rotated to orient the distal opening of the J-tip 104 in a desired direction within the target anatomy.

[0021] For example, if the target anatomy is a bile duct, the J-tip 104 may be rotated so that the distal opening of the lumen of the microcatheter 102 faces upstream of the bile duct or downstream toward the exit of the bile duct into the small intestine. When the J-tip 104 is oriented in the desired direction, a guidewire may be passed through the microcatheter 102, exit the opening at the distal end of the J-tip 104, and extend along the bile duct a desired distance in a desired direction out of the J-tip 104. At this point, a flexible electrosurgical sheath 110 having an electrosurgical tip 112 may be advanced over the microcatheter 102 and J-tip 104 to dilate the hole where the microcatheter 102 exits the small intestine and the hole where the microcatheter 102 enters the target bile duct. The electrosurgical tip may dilate the access hole (fistula) to, for example, 1.7 mm to 3.7 mm (5 to 11 French (Fr)). Electrodes on the electrosurgical tip may be activated when the tip is positioned at the entrance to and within the hole to dissect and dilate the hole for easier access to the target anatomy for further surgery (e.g., placing a stent therein to bypass the blockage).

[0022] The sharp 106 is generally used to create a starter hole in the anatomy so that the larger diameter J-tip 104 can be forced through the anatomy, and when the sharp 106 is removed, the J-tip 104 is firmly inserted through the puncture hole in the target anatomy. However, various problems can arise when performing this procedure.

[0023] For example, an access device 200 having a long, narrow sharp 201 can easily puncture tissue 203, i.e., reduce the puncture force required to create a hole, as shown in FIG. 2a. However, if there is a long setback between the distal tip of sharp 201 and the distal end of J-tip 202, the sharp must be pushed further into tissue 203 before J-tip 202 is firmly inserted into the puncture hole. Thus, when using a long, narrow sharp 201, there is a risk of pushing sharp 201 too far distally and inadvertently puncturing tissue 204 distal to the tissue 203 that was initially punctured. Conversely, if the long sharp 201 is not pushed in far enough to firmly anchor J-tip 202, there is a risk that J-tip 202 will retract and fall out of the puncture hole when sharp 201 is removed.

[0024] Alternatively, an access device 210 having a thicker, shorter sharp 211 may reduce the risk of inadvertently puncturing tissue 214 distal to the initially punctured tissue 213, or the risk of the J-tip 212 becoming dislodged from the puncture hole, as shown in Figure 2b. However, the force required to puncture the target tissue with a device including such a thicker sharp 211 is increased compared to the force required with a thinner, longer sharp.

[0025] In yet another example, the access device 220 has a J-tip 222 that abuts against the wall of the biological structure as the sharp portion 221 is advanced through the tissue 223, as shown in FIG. 2c, and may push the tissue 223 distally (i.e., tenting) when there is misalignment between the sharp portion 221 and the J-tip 222 and the J-tip 222 presses against the tissue wall. Tenting may occur if a blunt or less tapered J-tip is used. If a J-tip with a sharper end is used, there is a risk of damaging the surrounding tissue when the J-tip is rotated within the vessel to direct the guidewire.

[0026] Exemplary embodiments describe an EUS access device having one or more energized elements for high temperature puncture that addresses the above problems. An electrosurgical generator, such as an Erbe generator, can be used to apply RF cutting current to the device to facilitate passage of the puncture tip into tissue with low puncture force. The device is generally similar to the device described in Figures 1a-1b, with the following modifications:

[0027] FIG. 3 shows a microcatheter distal tip 300 (J-tip) (in a straight configuration) with an exposed metal end 302 that can be energized for hot puncture in an EUS access procedure. The metal end 302 is blunt to minimize trauma to the surrounding tissue as the J-tip 300 is rotated (in a curved configuration) within the vessel to orient the guidewire as desired. As will be appreciated by those skilled in the art, any sharp may be used for the distal tip 300. However, shorter sharps may be used without increasing the required puncture force. As noted above, increased puncture force is required to use a cold blunt J-tip with a short sharp. However, the hot blunt J-tip has been shown to puncture with a relatively low puncture force. In this embodiment, the hot blunt J-tip has a minimum setback of approximately 0.5 mm.

[0028] If the microcatheter is all metallic, the entire microcatheter except for the exposed metal end 302 is insulated to prevent heating or cutting of non-target tissue (i.e., tissue other than the target site). The exposed metal end 302 may be, for example, less than about 1 mm in length to minimize thermal damage to the target site during cutting. The exposed metal end 302 of the hot J-tip 300 may be wired to the handle and the remainder of the microcatheter may be formed of a different non-conductive material without the need for a separate electrically insulating coating.

[0029] 4 shows a sharp portion 400 with an exposed metal end 402 that may be energized for a hot puncture in an EUS access procedure. The exposed metal end 402 may be a short, pointed tip or may be relatively blunt. If the metal end 402 is sharp, the sharp portion 400 may be used for a cold puncture. However, if an attempted cold puncture is unsuccessful, the user has the option of energizing the exposed metal end 402 for a hot puncture.

[0030] Similar to the hot J-tip 300, the hot sharp 400 may have a flexible shaft of the same conductive material (e.g., metal) while the exposed metal end 402 is still insulated along its length (except for the exposed metal end 402). If the access cannula used with the sharp 400 is not intended to have a hot J-tip, the J-tip may be insulated to prevent the conduction of electricity from the sharp 400 through the J-tip. Alternatively, the J-tip may not be insulated and the access device may have both a hot sharp and a hot J-tip. In this case, only one of the J-tip or the sharp needs to be connected (by wire or otherwise) to an electrosurgical generator in order to effectively energize both tips.

[0031] The hot sharp cuts enough to allow the blunt cold J-tip to penetrate into the fistula, but energizing both tips may further reduce the puncture force. However, the selection of one or both of the J-tip and sharp to energize may vary depending on the nature of the treatment. For example, hot J-tips have been shown to create larger fistulas than cold J-tips. A larger fistula would not affect procedures such as stent implantation, given that the fistula needs to be enlarged further with an electrosurgical dilator prior to implanting the stent. However, for procedures where a smaller hole is desired (such as a rendezvous procedure), it may be preferable to use an energized sharp and a cold J-tip rather than energizing both the sharp and the J-tip.

[0032] In an alternative embodiment, a hot, blunt stylet may be used in place of the sharp. The stylet has a blunt distal end as opposed to a sharp that has a pointed distal end. In this embodiment, the stylet and J-tip may have a very short setback (e.g., 2 mm) to ensure that when the stylet tip is threaded into the canal, the access cannula is also threaded into the canal. This embodiment allows for smaller tissues to be targeted because there is less risk of the tip extending to the other side of the canal and inadvertently puncturing the other side.

[0033] The above embodiments may be performed endoscopically, using a device having a handle for controlling endoscopic surgery. FIG. 5 shows a handle 500 for controlling an EUS access procedure. The handle 500 extends from a proximal sharps hub 502 to a distal collar 504 that attaches to a coupling on the proximal end of an endoscope shaft. The sharps hub 502 is connected to the sharps such that the sharps hub 502 can be pulled to extract the sharps from the device. The sharps hub 502 includes a generator connection 520 through which a source of electrical energy is connected to the device. The handle 500 includes a length adjustment 506 that allows a user to adjust the length of the handle 500 such that when coupled to an endoscope, the length of the electrosurgical sheath extends distally a desired distance beyond the distal end of the endoscope (i.e., the length adjustment may be used to achieve extension of the device from the endoscope). The handle 500 further includes a puncture actuator 508 that is slidable on the base 512 of the handle 500 such that when unlocked by the puncture actuator lock 510, the J-tip and sharp can be advanced distally from a sheath (e.g., the electrosurgical sheath 110 shown in FIG. 1) so that the J-tip and sharp can penetrate the target tissue to a desired depth. The puncture actuator 508 includes a generator connection 522 through which a source of electrical energy is connected to the device.

[0034] The handle 500 further includes an electrosled 514 slidably mounted on the puncture actuator 508 for distally advancing a sheath over the J-tip to bring an electrosurgical tip (electrosurgical tip 112 shown in FIG. 1 ) at the distal end of the sheath into contact with target tissue for application of energy from the tip to treat the tissue (e.g., dissect and dilate tissue surrounding an opening made through the wall of the gastrointestinal tract and an access opening into the target pancreaticobiliary system). The electrosurgical sled 514 includes a generator connection 516 through which a source of electrical energy is connected to the device. The electrosurgical sled 514 is maintained in a desired position on the puncture actuator 508 by an electrosurgical sled lock 518. Similar to the puncture actuator lock 510, the electrosurgical sled lock 518 includes a protrusion that engages a geared surface on the base 512 until a corresponding lock is depressed to disengage the base 512 and allow the puncture actuator 508 or electrosurgical sled 514 to slide over the base 512.

[0035] The generator connection 516 forms a coupling for electrical energy transmitted to the electrosurgical sled 514. The generator connections 520, 522 apply energy to each of the metal end 402 of the sharp and the metal end 302 of the J-tip microcatheter, respectively, in the manner described above. The base 512 may include a depth indicator thereon to provide greater control of the sharp / J-tip penetration depth and electrosurgical sheath length. As described above, the ideal depth of penetration may vary for different procedures and different sharp / J-tip configurations. Thus, the handle 500 has precise penetration depth control that is adaptable to a variety of access devices having different penetration depths.

[0036] FIG. 6 shows a fine needle aspiration (FNA) needle 600 with a blunt end 602 that can be energized for high temperature puncture in EUS access procedures. The FNA needle 600 has a lumen for a guidewire to extend therethrough. In contrast to sharp needles, blunt needles facilitate guidewire directionality with less risk of slicing the guidewire. Despite being blunt, the blunt end 602 is capable of puncturing anatomy when energized.

[0037] Each of the energized puncture elements may be activated by an electrosurgical plug extending from or incorporated into the endoscope handle. The hot tip element may be activated at any time during an endoscopic procedure. Thus, for example, a clinician may begin a procedure with a cold sharp tip and, if a cold puncture is not achieved, activate the hot tip to achieve the hot puncture.

[0038] Those skilled in the art will appreciate that modifications may be made to the above-described embodiments without departing from the inventive concept. It should further be understood that structural elements and methods associated with one of the embodiments may be incorporated into other embodiments. It is therefore understood that the invention is not limited to the specific embodiments disclosed, but rather, modifications are within the scope of the invention as defined by the appended claims.

Claims

1. a catheter including a lumen extending therethrough and sized and shaped to pass through the endoscope shaft and extend to a target tissue within the body; a puncture tool sized and shaped to pass through the lumen of the catheter and extend distally from the distal end of the catheter; at least one of the catheter and the piercer includes an electrode formed thereon, the electrode being configured to be energized from a handle of the device when the piercer pierces the target tissue as the piercer extends distally from a distal end of the catheter; 13. An apparatus comprising:

2. The device of claim 1 , wherein the distal end of the catheter is biased to assume a J-shaped curve when unconstrained.

3. The device of claim 1 or 2, wherein the distal end of the catheter is rotatable about a longitudinal axis of the catheter to direct a distal opening of the distal end in a desired direction within the target tissue.

4. The device according to any one of claims 1 to 3, wherein the distal end of the catheter is configured to follow the piercer into the target tissue when the piercer pierces the target tissue.

5. 5. The apparatus of claim 4, further comprising an electrosurgical sheath longitudinally slidable along the outside of the catheter, the electrosurgical sheath having an electrosurgical tip for dilating an access hole created by the puncture in the target tissue.

6. The apparatus of any one of claims 1 to 5, wherein the distal end of the catheter is straightened when the piercer is extended into the distal end of the catheter.

7. The device according to any one of claims 1 to 6, wherein the electrode is formed at a distal end of the catheter.

8. 8. The device of claim 7, wherein a proximal portion of the catheter between the distal end of the catheter and the distal end of the handle is formed of a non-conductive material and further includes a conductor connecting the electrode to the handle.

9. The device of claim 7 further comprising an electrode formed on a distal end of the piercer.

10. The device according to any one of claims 1 to 9, wherein the electrode is formed at a distal end of the piercer.

11. The device of claim 10 , further comprising an insulating layer extending along the piercer from the proximal end of the electrode to the proximal end of the piercer.

12. The handle is A length adjustment part; A sharp portion hub; a puncture actuator for advancing the puncture tool and the catheter distally out of a sheath of the device; an electrosurgical sled slidably mounted on the puncture actuator for advancing the sheath distally over the catheter to apply energy to the target tissue using electrodes formed on the sheath; A puncture actuator lock; an electrosurgical thread lock for locking the position of the sheath in a desired position relative to the catheter; a first generator connection on the electrosurgical sled configured to connect to a source of electrical energy; The apparatus of any one of claims 1 to 11, further comprising:

13. 13. The device of claim 12, wherein the handle further comprises at least one of a second generator connection on the puncture actuator configured to connect to a source of electrical energy and a third generator connection on the sharps hub configured to connect to a source of electrical energy.

14. a catheter including a lumen extending therethrough and sized and shaped to pass through the endoscope shaft and extend to a target tissue within a living body; a puncture tool sized and shaped to pass through the lumen of the catheter and extend distally from the distal end of the catheter; at least one of the catheter and the puncture tool includes an electrode formed thereon, the electrode being configured to be energized from a handle of the device when the puncture tool punctures the target tissue when the puncture tool is extended distally from the distal end of the catheter; an electrosurgical sheath longitudinally slidable along the outside of the catheter, the electrosurgical sheath having an electrosurgical tip for dilating an access hole created by the puncture in the target tissue; Including, the system.

15. 15. The system of claim 14, wherein the distal end is configured to be rotatable about a longitudinal axis of the catheter to direct a distal opening of the distal end in a desired direction within the target tissue.

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