System and method for affecting tissue structure movement

Abstract

The present invention relates generally to medical devices and procedures for placing medical devices between adjacent tissue structures. In particular, the present invention relates to endoscopic systems and methods for preventing or minimizing movement between tissue walls to facilitate placement of a stent therebetween.

Description

[0001] (division of 201880021646.4)

[0002] Cross Reference to Related Applications

[0003] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application Serial No. 62 / 476,995, filed March 27, 2017, the entire contents of which are incorporated herein by reference for all purposes. TECHNICAL FIELD

[0004] The present invention relates generally to the field of devices and procedures for placing medical devices between adjacent tissue structures. In particular, the present invention relates to endoscopic systems and methods for preventing or minimizing movement between tissue walls to facilitate placement of a stent therebetween. BACKGROUND

[0005] While endoscopic imaging modalities, such as fluoroscopy and endoscopic ultrasound (EUS) allow for direct visualization of anatomy beyond the tissue in front of the endoscope, the inability to control (e.g., stabilize, fixate, anchor, etc.) these distal anatomical structures during an endoscopic procedure presents a challenge. For example, medical procedures, such as gastrojejunostomy, hepatocholecystostomy, and cholecystic drainage require placement of a catheter (e.g., stent, etc.) within appropriate portions of the proximal and distal tissue walls. The tendency to lose control of the distal tissue wall during a transmural stent deployment procedure presents a significant technical challenge to medical professionals, particularly when direct visual images of the distal tissue wall are not available. Failure to properly position a fluid catheter within appropriate portions of the tissue walls can result in serious medical complications.

[0006] By minimizing or preventing movement of the proximal and distal tissue walls away from each other during a transmural stent placement procedure, various advantageous medical outcomes can be achieved by the systems and / or methods of the present invention. SUMMARY

[0007] In one aspect, the present invention relates to a system comprising a needle comprising a proximal end, a sharp distal end, and a lumen extending therebetween. An elongated member can be slidably disposed within the lumen, wherein a distal portion of the elongated member is configured to move between a first configuration when disposed within the lumen and a second configuration when disposed distally beyond the sharp distal end. The distal portion of the elongated member can be substantially linear in the first configuration and substantially non-linear in the second configuration. The second configuration can comprise a loop, a spiral, and a figure-8. The distal portion can split along a longitudinal axis of the elongated member to define first and second branches. The first and second branches can be substantially collinear with the elongated member in the first configuration. The first and second branches can form a Y-shape, a T-shape, or a W-shape in the second configuration. Alternatively, the first and second branches form a substantially spherical or elliptical structure in the second configuration.

[0008] In one aspect, the present invention relates to a system comprising a needle comprising a proximal end, a sharp distal end, and a lumen extending therebetween. An elongated member can be slidably disposed within the lumen. The elongated member can comprise a control rod, and a sheath slidably disposed about the control rod, wherein a distal portion of the elongated member is configured to move between a first configuration when disposed within the lumen and a second configuration when disposed distally beyond the sharp distal end. A distal portion of the sheath can comprise at least one slit formed therein, wherein a distal end of the control rod is attached to a distal end of the sheath. The distal portion of the sheath can move from the second configuration to the first configuration by advancing the sheath distally over the control rod. Alternatively, the distal portion of the sheath can move from the first configuration to the second configuration by retracting the control rod proximally through the sheath. Alternatively, the distal portion of the sheath can move from the first configuration to the second configuration by advancing the sheath distally over the control rod. The distal portion of the sheath can move from the second configuration to the first configuration by advancing the control rod distally through the sheath. Alternatively, the distal portion of the sheath can move from the second configuration to the first configuration by retracting the sheath proximally over the control rod. The distal portion of the sheath can form a basket in the second configuration.

[0009] In another aspect, the present application is directed to a method comprising advancing a needle having a sharp distal end and a lumen running from a proximal end to the distal end through a tissue wall of a first body lumen and a tissue wall of a second body lumen adjacent to the first body lumen, and advancing an elongate member distally through the lumen of the needle such that a distal portion of the elongate member moves to a second configuration in which it is in contact with a portion of the tissue wall of the second body lumen to affect a position of the second body lumen relative to the first body lumen. The method can further comprise withdrawing the needle over the elongate member and advancing a stent delivery system over the elongate member such that a distal end of the stent delivery system forms opposing holes in the tissue walls of the first and second body lumens. The method can further comprise deploying a stent from the stent delivery system between the first and second body lumens. The method can further comprise retracting the elongate member distally through the stent delivery system and removing the stent delivery system. BRIEF DESCRIPTION OF DRAWINGS

[0010] Non-limiting embodiments of the present application are described by way of example with reference to the accompanying drawings. In the drawings, each identical or nearly identical component that is illustrated in various figures is typically represented with a single numeral. For purposes of clarity, not every component is called out in every drawing where it appears. In the drawings:

[0011] Figures 1A to 1G Perspective views of a system in a delivery Figure 1A ) and deployed Figures 1B to 1G ) configurations according to embodiments of the present application are provided.

[0012] Figures 2A to 2E Perspective views of a system in a delivery Figure 2A ) and deployed Figures 2B to 2E ) configurations according to embodiments of the present application are provided.

[0013] Figures 3A to 3C Perspective views of a system in a delivery Figures 3A to 3B ) and deployed Figure 3C ) configurations according to one embodiment of the present application are provided.

[0014] Figures 4A to 4F A perspective view of a stent deployment procedure using a system according to one embodiment of the present application is provided.

[0015] Figures 5A to 5C A perspective view of stent deployment using a system according to one embodiment of the present application is provided. Figure 2E A perspective view of stent deployment using a system according to one embodiment of the present application is provided. DETAILED DESCRIPTION

[0016] The present application is not limited to the particular embodiments described. The terminology used in the context of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting as to the scope of the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0017] Although embodiments of the present application are described with specific reference to certain procedures, such as gastrojejunostomy, the systems and methods described herein can be used to position a fluid conduit between various adjacent tissue walls, organs, blood vessels, and / or body cavities.

[0018] As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", or "includes" and / or "including" when used herein, specify the presence of stated features, regions, steps, elements and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and / or groups thereof.

[0019] As used herein, the term "distal" refers to the end of the device that is farthest from a medical professional when the device is introduced into a patient, while the term "proximal" refers to the end of the device that is closest to the medical professional when the device is introduced into a patient.

[0020] In various embodiments described herein and in other embodiments, the present application relates to a system that prevents or minimizes movement between tissue walls during a transmural medical procedure where direct visual images and / or control of the distal tissue wall is difficult or impossible to obtain.

[0021] Reference is made to Figure 1AIn one embodiment, a system 100 of the present application can include a tissue-penetrating element 110 (e.g., needle, etc.) including a proximal end (not shown), a sharp distal end 114, and a lumen 116 extending therebetween. An elongate member 120 (e.g., rail, guidewire, etc.) including a proximal end (not shown) and a distal end 124 can be slidably disposed within the lumen 116 of the tissue-penetrating element 110. A distal portion 125 of the elongate member 120 can be split (e.g., separated) along its longitudinal axis to define first and second branches 125a, 125b (e.g., tines, prongs, branches, forks, arms, etc.). The first and second branches 125a, 125b can be substantially co-linear with the longitudinal axis of the elongate member 120 when disposed within the lumen 116 of the tissue-penetrating element 110. At least the distal portion 125 of the elongate member 120 can include various shape memory materials (e.g., metals, alloys, polymers, etc.) as known in the art configured to move between a first configuration when disposed within the lumen 116 of the tissue-penetrating element 110 and a second configuration when disposed in a position distally beyond the sharp distal end 114 of the tissue-penetrating element 110. The distal portion 125 of the elongate member 120 is not limited to two branches, but can include any number of branches (e.g., three or more branches).

[0022] Referring to Figure 1B In one embodiment, the first and second branches 125a, 125b can move or deflect substantially perpendicular to the longitudinal axis of the elongate member 120 to form a "T-shape" when in the second configuration. Referring to Figure 1C In one embodiment, the first and second branches 125a, 125b can move or deflect substantially tangentially to the longitudinal axis of the elongate member 120 to form a "Y-shape" when in the second configuration. Referring to Figure 1D In one embodiment, the first and second branches 125a, 125b can bend back (back-bend) along / with or parallel to the longitudinal axis of the elongate member 120 to form a "W-shape" when in the second configuration. Referring to Figure 1E In one embodiment, the first and second branches 125a, 125b can curl back (curl back) along / with the longitudinal axis of the elongate member 120 to form a relatively substantially spherical (e.g., circular) shape when in the second configuration. Referring to Figure 1F In one embodiment, the first and second branches 125a, 125b can curl back along / with the longitudinal axis of the elongate member 120 to form a relatively substantially elliptical (e.g., oval, oblong, etc.) shape when in the second configuration. Referring to Figure 1GIn one embodiment, the first and second branches 125a, 125b can be curled back along / with the longitudinal axis of the elongated member 120 to form opposing substantially oval shapes that are spaced apart (e.g., separated) from the longitudinal axis of the elongated member in the second configuration. While the distal portion 125 of the elongated member 120 is depicted as forming a substantially symmetrical structure, in various embodiments, the first and second branches 125a, 125b can form Figures 1B to 1G any combination of the second configuration depicted or other configurations not depicted. In various embodiments, when in the second configuration, the first and second branches 125a, 125b move (e.g., deflect, bend, twist, compress, etc.) independently of one another when placed in contact with the inner surface of a tissue wall, as discussed below.

[0023] Reference is made to Figure 2A In one embodiment, a system 200 of the present application can include a tissue-penetrating element 210 (e.g., needle, etc.) including a proximal end (not shown), a sharp distal end 214, and a lumen 216 extending therebetween. An elongated member 220 (e.g., rail, guidewire, etc.) including a proximal end (not shown) and a distal end 224 can be slidably disposed within the lumen 216 of the tissue-penetrating element 210. At least a distal portion 225 of the elongated member 220 can include various shape memory materials (e.g., metals, alloys, polymers, etc.) as known in the art configured to move between a first configuration when disposed within the lumen 216 of the tissue-penetrating element 210 and a second configuration when disposed (advanced) distally beyond the sharp distal end 214 of the tissue-penetrating element 210. Reference is made to Figure 2B In one embodiment, the distal portion 225 of the elongated member 220 can form a "loop" or "cuff" when in the second configuration. Reference is made to Figure 2C In one embodiment, the distal portion 225 of the elongated member 220 can be bent about 180 degrees relative to the longitudinal axis of the elongated member 220 to form a "reverse coil" or "reverse helix" around a portion of the elongated member 220 when in the second configuration. Reference is made to Figure 2D In one embodiment, the distal portion 225 of the elongated member 220 can form the shape of an "8," a "lariat," or a "screwdriver" when in the second configuration. Reference is made to Figure 2E In one embodiment, the distal portion 225 of the elongated member 220 can be bent to form a "crossbar" extending across the longitudinal axis of the elongated member 220 when in the second configuration.

[0024] The various second configurations of the distal portion 125, 225 can provide a number of additional benefits to further immobilize the distal tissue wall when the elongated member 120, 220 is retracted proximally. As non-limiting examples, Figures 1B to 1DThe ends of the first and second prongs 125a, 125b depicted in any of the Figures 1B to 1G One or more of the branches 125a, 125b in any of the Figures 2B to 2E The distal portion 225 of the elongated member 220 of any of the Figures 1B to 1D A portion of the surface of the branches 125a, 125b of any of the Figures 1E to 1G One or both of the spherical or oval shapes of any of the

[0025] Referring to Figures 3A to 3C In one embodiment, a system 300 of the present invention can include a tissue- penetrating element 310 (e.g., needle, etc.) including a proximal end (not shown), a sharp distal end 314, and a lumen 316 extending therebetween. An elongated member 320 can be slidably disposed within the lumen 316 of the tissue-penetrating element 310. The elongated member 320 can include a control rod 322 slidably disposed within a sheath 326. A distal end 324 of the control rod 322 can be attached to a distal end 327 of the sheath 326. A distal portion 325 of the sheath 326 can include one or more slits 329 formed therein and configured to move between a first configuration when disposed within the lumen 316 of the tissue-penetrating element 310 Figure 3A ) and a second configuration when disposed distally past the sharp distal end 314 of the tissue-penetrating element 310 Figure 3C ).

[0026] For example, at least the distal portion 325 of the sheath 326 can include various materials including, but not limited to, shape memory materials such as Nitinol, polyether ether ketone (PEEK), etc., in which one or more slits 329 are formed using, for example, laser cutting. The control rod 322 Figure 3B) advancing distally to advance the elongated member 320 through the lumen 316 of the tissue-penetrating element 310. In one embodiment, the distal portion 325 of the sheath 326 can be moved to the second configuration by advancing the sheath 326 distally over / along the control rod 322. Alternatively, the distal portion 325 of the sheath 326 can be moved to the second configuration by retracting the control rod 322 proximally through the sheath 326 Figure 3C ) / within the sheath 326. In either of the two embodiments, the one or more slits 329 can allow the distal portion 325 to form a "basket" comprising a series of arms or flaps configured to engage a distal tissue wall. In one embodiment, the distal portion 325 can include one or more hooks, barbs, prongs, etc. to achieve enhanced friction against a distal tissue wall. Although Figures 3A to 3C One embodiment is depicted in which the distal portion 325 includes 5 slits configured to form 5 arms when in the second configuration, in various embodiments, the distal portion can include any number of slits configured to form various second configurations.

[0027] In one embodiment, the elongated members 120, 220, 320 disclosed herein can be disposed within and delivered through a tissue-penetrating element 110, 210, 310 comprising a 19 or 21 -gauge needle for fine needle aspiration (FNA) or fine needle biopsy (FNB) procedures, as known in the art. Additionally or alternatively, the tissue-penetrating element 110, 210, 310 and / or the elongated member 120, 220, 320 can beneficially include a coating, such as a fluorinated polymer or p-xylylene, to provide electrical insulation and / or improved lubricity. To prevent coring of proximal or distal tissue walls, the distal portion 125, 225, 325 of the elongated member 120, 220, 320 can be configured to occlude the lumen 116, 216, 316 at or proximal to the sharp distal end 114, 214, 314 of the tissue-penetrating element 110, 210, 310.

[0028] In one embodiment, a system 100, 200, 300 of the present invention can be delivered through a working channel of an endoscope. Referring to Figure 4AIn use and by way of example, an ultrasonic endoscope 130 can be advanced through the esophagus into a first body lumen 140 (e.g., stomach). The distal end 132 of the endoscope 130 can include a camera 137, a light source 138, and an ultrasonic transducer 139. Using direct vision (e.g., light source 138 and camera 137), the distal end 132 of the endoscope 130 can be positioned adjacent to a tissue wall 142 (e.g., proximal tissue wall) of the first body lumen 140 that is in the vicinity of a tissue wall 152 (e.g., distal tissue wall) of a second body lumen 150 (e.g., duodenum or jejunum). The second body lumen 150 can then be imaged through the first tissue wall 142 by switching the endoscope 130 from direct vision to ultrasonic vision (e.g., turning off the light source 138 and turning on the ultrasonic transducer 139). The system 100 can then be advanced through the working channel 136 of the endoscope 130 such that the sharp distal end 114 of the tissue-penetrating element 110 penetrates the first and second tissue walls 142, 152 and extends into the second body lumen 150.

[0029] Referring to Figure 4B The elongate member 120 can then be advanced distally past the sharp distal end of the tissue-penetrating element such that the distal portion 125 moves within the second body lumen 150 to the second configuration. The tissue-penetrating element can then be removed (e.g., withdrawn proximally) through the working channel 136 of the endoscope 130 along / over the elongate member 120. The elongate member 120 can then be retracted proximally to place the distal portion 125 in contact with the interior of the second distal tissue wall 152 and with sufficient force to minimize or prevent (e.g., anchor) movement of the distal tissue wall 162 relative to the proximal tissue wall 152.

[0030] Referring to Figure 4CWith the proximal and distal tissue walls 142, 152 sufficiently fixed with respect to one another, a stent delivery system 160 loaded with a stent 162 thereon can be advanced through the working channel 136 of the endoscope 130. The stent delivery system 160 can include a lumen 166 configured to slide over / along the elongate member 120. The distal end of the stent delivery system 160 can include a cutting element, such as an electrocautery surface, configured to create opposing openings (e.g., holes) through the first and second tissue walls 142, 152. In one embodiment, the distal portion 125 of the elongate member 120 can provide a firm / secure platform against which the electrocautery surface of the stent delivery system 160 can press when forming the opposing openings. The distal portion 125 can provide the additional benefit of establishing separation between the opposing tissue walls of the second body lumen 150 and the stent delivery system to prevent accidental cutting by the cutting element. In one embodiment, one (or both) of the oval portions of the distal portion 125 can be deflected away from the longitudinal axis of the elongate member 120 to provide holding pressure over a greater surface area of the distal tissue wall. Additionally or alternatively, the ability of the distal portion 125 to deflect away from the longitudinal axis of the elongate member 120 can provide space to allow: 1) the cutting element of the delivery system 160 to fully penetrate the second body lumen 150, 2) unobstructed deployment of the distal flange 166 of the stent 162 Figure 4D ), and / or 3) the introduction of additional cutting elements to further dilate (e.g., enlarge) the tissue openings without exerting excessive force on the opposing tissue walls of the second body lumen 150. Additionally, the oval shape can provide a degree of flexibility to the distal portion such that the stent delivery system 160 can be advanced into the second body lumen 150 a sufficient distance to deploy the distal flange without further pushing the distal portion 125 against the opposing tissue walls. The distal portion 125 of the elongate member 120 can include a soft and / or compliant surface or coating to prevent trauma to the opposing tissue walls in the event of contact therebetween.

[0031] With reference to Figure 4D , the exterior of the stent delivery system 160 can then be retracted proximally along the lumen 166, the elongate member 120, and the stent 162 to deploy the distal flange 165 of the stent 162 within the second body lumen 150. With reference to Figure 4E , the exterior of the stent delivery system 160 can be further retracted along the lumen 166, the elongate member 120, and the stent 162 to deploy the proximal flange 164 of the stent 162 within the first body lumen 140. With reference to Figure 4FWith the proximal and distal flanges 164, 165 properly deployed within the first and second body lumens 140, 150, the elongated member 120 can be proximally retracted with sufficient force such that the distal portion 125 moves from the second configuration to the first configuration for removal through the lumen 166 of the stent delivery system. The endoscope 130, the stent delivery system 160, and the elongated member 120 can then be removed from the patient. Figures 4D to 4F The stent configurations depicted are provided as non-limiting examples, and can include various different shapes, configurations, orientations, sizes, and / or materials as needed to provide a flow path between adjacent tissue walls. Additionally, the outer and / or inner surfaces of the stent can be fully or partially covered (e.g., across the saddle region between the proximal and distal flanges) to prevent fluid leakage between the tissue walls. Although Figures 4E to 4F The gap between the tissue walls of the first and second body lumens 140, 150 after placement of the stent is depicted, in other embodiments, the procedure can result in the tissue walls being apposed to one another along the saddle region with the proximal and distal flanges providing contact with the respective inner surfaces of each tissue wall.

[0032] Although the systems 100, 200, 300 disclosed herein are configured to minimize or prevent the proximal and distal tissue walls from moving away from one another during the medical procedure, rather than moving either tissue wall toward the other, in one embodiment, the elongated member 120, 220, 320 can be proximally retracted with sufficient force such that the distal portion 125, 225, 325 pulls the distal tissue wall over the stent delivery system 160 to deploy the distal flange within the second body lumen 150.

[0033] Referring to Figures 5A to 5C In one embodiment, Figure 2E The distal portion 225 of the elongated member 220 can include a first dimension Dl (e.g., width), a second dimension D2 (e.g., height), and a third dimension D3 (e.g., thickness) relative to a longitudinal axis of the elongated member 220. As a non-limiting example, the first dimension Dl can be about 1.00 inch, the second dimension D2 can be about 0.78 inch, and the third dimension D3 can be about 0.33 inch. In various embodiments, the first, second, and third dimensions Dl-D3 of the distal portion 225 can provide a space within which the distal flange 165 of the stent 162 can be deployed (e.g., within the second body lumen, as outlined above) while the distal portion 225 of the elongated member remains in contact with the tissue walls of the second body lumen throughout the stent deployment procedure.

[0034] In various embodiments, the elongate members 120, 220, 320 disclosed herein can include sufficient flexibility and strength to repeatedly slide into and out of a tissue-penetrating element or other medical device (e.g., a retracting catheter, etc.) without causing damage / fracture and while maintaining the ability to move to a second configuration within a second body lumen (e.g., to provide the necessary retention strength). Additionally, any of the elongate members 120, 220, 320 disclosed herein can include a suitable coating for slidable movement within a tissue-penetrating element or other medical device. In various embodiments, such a coating can also impart dielectric strength to all or a portion of the elongate member.

[0035] The medical devices of the present application are not limited to endoscopes and can include a variety of medical devices for accessing body passageways, including, for example, catheters, bronchoscopes, ureteroscopes, duodenoscopes, colonoscopes, arthroscopes, cystoscopes, hysteroscopes, etc. Ultimately, while embodiments of the present application have been described for use with endoscopes, the systems of the present application can be positioned within a patient's body in the absence of an accompanying medical device.

[0036] In accordance with the present application, all devices and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices and methods of this application have been described in terms of preferred embodiments, it will be apparent to those with ordinary skill in the art that variations in substitutions and modifications can be made in the device and / or method and in the steps of the methods described herein or in the sequence of steps without departing from the concept, spirit and scope of the application. All such similar substitutes and modifications are intended to be within the spirit and scope of the application as defined by the claims appended hereto.

Claims

1. A system for affecting movement of a tissue structure, comprising: an elongated member longitudinally slidable through a lumen and laterally slidable through a proximal wall of a body lumen, the elongated member including a distal portion configured to move between a first configuration when disposed within the lumen and a second, expanded configuration when disposed distally beyond a distal end of the lumen and distally through the proximal wall of the body lumen; and a cutting element, wherein, in the second configuration, the distal portion of the elongated member: provides a platform within the body lumen against which the cutting element is pressed when cutting through the proximal wall of the body lumen; and is dimensioned to extend transverse to an axis of the body lumen to form a space within the body lumen between a proximal wall of the body lumen and a distal wall of the body lumen, the distal portion of the elongated member being disposed within the space to shield the distal wall of the body lumen from other instruments entering the body lumen through the proximal wall of the body lumen.

2. The system of claim 1, wherein the elongated member is a guidewire.

3. The system of claim 1, wherein the distal portion of the elongated member in the second configuration is dimensioned to form a space to allow the cutting element to extend through the proximal wall of the body lumen into the body lumen without cutting into or applying excessive force on the distal wall of the body lumen opposite the proximal wall.

4. The system of claim 1, further comprising a stent, wherein the distal portion of the elongated member is dimensioned to form a space within the body lumen for at least a portion of the stent to expand.

5. The system of claim 4, wherein the stent has a distal flange, and the distal portion of the elongated member is dimensioned to form a space for the distal flange of the stent to deploy unimpeded.

6. The system of claim 4, further comprising a stent delivery system having a cutting element, wherein the distal portion of the elongated member is dimensioned to form a space to allow the cutting element to extend through the proximal wall of the body lumen into the body lumen without cutting into the distal wall of the body lumen opposite the proximal wall.

7. The system of claim 6, wherein the distal portion of the elongated member is dimensioned to remain in contact with the body lumen during deployment of the stent.

8. A system for affecting movement of a tissue structure, comprising: an elongated member; and a stent, wherein: the elongated member has a distal portion distal of the stent configured to move between a first configuration when disposed within a lumen and a second configuration when disposed distally beyond a distal end of the lumen and distally through a proximal wall of a body lumen; and in the second configuration, the distal portion of the elongated member provides a space for at least a portion of the stent to deploy within the body lumen while the distal portion of the elongated member is disposed within the body lumen.

9. The system of claim 8, further comprising a stent delivery system having a cutting element, wherein the distal portion of the elongated member is dimensioned to form a space to allow the cutting element to extend through the proximal wall of the body lumen into the body lumen without cutting into a distal wall of the body lumen opposite the proximal wall of the body lumen. ​ 10. The system of claim 8, further comprising a stent delivery system having a cutting element, the distal portion of the elongated member providing a platform against which the cutting element of the stent delivery system is pressed.

11. The system of claim 8, wherein in the second configuration, the distal portion of the elongated member extends transversely to the proximal portion of the elongated member.

12. The system of claim 8, wherein the distal portion of the elongated member provides a space between the proximal wall of the body lumen and a distal wall of the body lumen opposite the proximal wall of the body lumen to shield the distal wall of the body lumen from other instruments entering the body lumen through the proximal wall of the body lumen.

13. A system for affecting movement of a tissue structure, comprising: an elongated member longitudinally slidable through a lumen and laterally slidable through a proximal tissue wall and through a proximal wall of a body lumen; and a stent, wherein: the elongated member includes a distal portion configured to move between a first configuration when disposed within the lumen and an expanded second configuration when disposed distally beyond a distal end of the lumen and through the proximal wall of the body lumen; wherein, in the second configuration, the distal portion of the elongated member is configured and positioned to minimize movement of the proximal wall of the body lumen relative to the proximal tissue wall when the stent is deployed within the body lumen, thereby separating the proximal wall of the body lumen from a distal wall of the body lumen so that the stent is deployed relative to the body lumen while the distal portion of the elongated member is disposed within the body lumen.

14. The system of claim 13, further comprising a tissue-penetrating element having a sharp distal end configured to penetrate the proximal wall of the body lumen and a lumen defined through the tissue-penetrating element through which the elongated member extends.

15. The system of claim 13, wherein, in the second configuration, the distal portion of the elongated member is configured to increase a holding pressure on a surface of the proximal wall of the body lumen.

16. The system of claim 15, wherein, in the second configuration, the distal portion of the elongated member is configured to gradually increase the holding pressure as the elongated member is retracted proximally.

17. The system of claim 13, wherein the distal portion of the elongated member is configured to enhance friction against the proximal wall of the body lumen.

18. The system of claim 13, further comprising a stent delivery system having the stent and a cutting element, wherein, in the second configuration, the distal portion of the elongated member minimizes movement of the proximal wall of the body lumen relative to the proximal tissue wall to facilitate advancement of the cutting element and the stent through the proximal wall of the body lumen.

19. The system of claim 18, wherein, in the second configuration, the distal portion of the elongated member provides a space between the proximal wall of the body lumen and the distal wall of the body lumen opposite the proximal wall of the body lumen to prevent the cutting element from inadvertently cutting the distal wall of the body lumen. ​

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