Stent insertion device and method

Abstract

The present invention generally relates to an apparatus for placing a stent at a desired location in the human body. In particular, but not exclusively, the apparatus is configured to place a stent in the ureter or other passageway or space in the human body. The present invention may be embodied as an apparatus for inserting a stent into a body structure of a target, the apparatus comprising a stent guidewire, a first moving means configured to move the stent guidewire towards the body structure of the target, a stent pusher disposed around the stent guidewire, and a second moving means configured to move the stent pusher relative to the stent guidewire independently of the stent guidewire.

Description

FIELD OF THEINVENTION

[0001]

[0001] The present invention relates generally to a device for placing a stent at a desired location in the human body. In particular, but not exclusively, the device is configured to place a stent in the ureter or other passageway or space in the human body. BACKGROUND OF THEINVENTION

[0002]

[0002] A stent is a tubular structure that is placed within the human body to restore patency to passageways, thereby allowing bodily fluids to flow. In other applications, stents are used to promote cross-sectional expansion of passageways within the body. In yet further applications, stents may be used prophylactically to prevent blockages.

[0003]

[0003] A common site for stent placement is in the ureter. The ureter must remain patent to allow urine to drain from the kidney into the bladder. Blockage of the ureter often presents with symptoms including pain, fever and vomiting. Progression of the blockage can lead to infection and serious kidney damage.

[0004]

[0004] The ureter may become blocked or partially obstructed by an internal obstruction, such as a ureteral stone. Alternatively, an external object, such as a tumor, lymph node, or fibrosis, may compress the ureter. In other situations, the ureter may become kinked or its wall may thicken. Ureteral stents may be placed to prevent blockages caused by procedures such as kidney stone lithotripsy.

[0005]

[0005] Ureteral stents generally take the form of a hollow tube made from flexible plastic. Stents used for adult subjects are usually about 45cm in length, with a straight section about 22cm to 30cm long and a coiled section at each end. The coiled sections hold the stent in place. The coil at one end is located in the renal pelvis and the other end is located in the bladder.

[0006]

[0006] Ureteral stent insertion is often performed under general anesthesia. A cystoscopy is first performed to inject a contrast agent into the ureter. Fluoroscopy provides real-time images and outlines the urinary system from the kidney to the bladder. A guidewire is inserted into the ureter and the end advanced into the renal pelvis. A stent is placed over the wire and is held generally linear by the wire as it is advanced toward the renal pelvis with a pusher. Once the terminal end of the stent is positioned within the renal pelvis, the guidewire is withdrawn, allowing each end of the stent to assume its normal coiled configuration.

[0007]

[0007] Existing methods of ureteral stent insertion present several problems.

[0008]

[0008] A significant problem is that ureteral stent insertion cannot be performed in an emergency department or general clinical setting, given that a specialized urologist is required and specialized equipment is usually only available in the operating room. Ureteral stent insertion is usually beyond the skill of non-specialized medical personnel. Expertise and experience are required first to operate specialized equipment in the context of a complex multi-step process. Further expertise and experience are required to ensure that the stent is advanced enough so that the distal coiled portion is located within the renal pelvis, but that the guidewire or stent is advanced to such an extent that it does not injure the renal pelvic tissue and that the stent is not completely lost within the ureter. Thus, stent insertion is often delayed up to an entire day, given the need to convene the necessary specialist team, including a urologist, and to coordinate access to the imaging equipment set. During that time, the subject may be in significant pain and at risk of renal pelvic injury resulting from ureteral obstruction.

[0009]

[0009] A further problem is that ureteral stents can be difficult to properly insert, even in expert hands. Precise manipulation of the guidewire and stent pusher requires a high level of manual dexterity. Even with fluoroscopic guidance, the subject may suffer some renal pelvic injury due to the wire or stent being advanced too far into the kidney.

[0010]

[0010] It is an aspect of the present invention to provide an improvement over prior art devices and methods for inserting stents, particularly ureteral stents. It is a further aspect of the present invention to provide a useful alternative to prior art devices and methods for inserting stents, particularly ureteral stents.

[0011] The discussion of documents, acts, materials, devices, articles and the like in this specification is solely for the purpose of providing a context for the present invention. No suggestion or implied that any of these matters formed part of the prior art or were common general knowledge in the art to which this invention pertains prior to the priority date of each claim in this application. Summary of the Invention

[0012] In a first, but not necessarily in its broadest aspect, the present invention provides an apparatus for inserting a stent into a body structure of a subject, the apparatus comprising: A stent guidewire; a first moving means configured to move the stent guidewire towards the body structure of the target; a stent pusher disposed around the stent guidewire; a second moving means configured to move the stent pusher relative to the stent guidewire independently of the stent guidewire; The present invention provides an apparatus comprising:

[0013] In one embodiment of the first aspect, the device is configured such that the stent guidewire and the stent pusher are movable together in an interdependent manner.

[0014] In one embodiment of the first aspect, the first and / or second moving means are configured such that the stent guidewire and the stent pusher are movable together in an interdependent manner.

[0015]

[0015] In one embodiment of the first aspect, the device is configured to alternately (i) move the stent pusher relative to the stent guidewire independently of the stent guidewire, and (ii) move the stent guidewire and the stent pusher in an interdependent manner.

[0016]

[0016] In one embodiment of the first aspect, the first and / or second moving means are configured to alternately (i) move the stent pusher relative to the stent guidewire independently of the stent guidewire, and (ii) move the stent guidewire and the stent pusher in an interdependent manner.

[0017]

[0017] In one embodiment of the first aspect, the device includes a mechanism configured to alternately lock and unlock the first and second moving means relative to each other so that (i) the stent pusher is movable relative to the stent guidewire independently of the stent guidewire, and (ii) the stent guidewire and stent pusher are movable in a mutually dependent manner.

[0018] In one embodiment of the first aspect, the first and second movement means are independently lockable to prevent movement in a certain direction.

[0019]

[0019] In one embodiment of the first aspect, the first and / or second moving means are movable, and movement of the first moving means causes movement of the stent guidewire toward the body structure, and movement of the second moving means causes movement of the stent pusher along the stent guidewire.

[0020]

[0020] In one embodiment of the first aspect, the device comprises a mechanism configured to alternately lock and unlock the first and second moving means relative to each other so that (i) the stent pusher is movable relative to the stent guidewire independently of the stent guidewire, and (ii) the stent guidewire and stent pusher are movable in a mutually dependent manner, wherein when unlocked, the mechanism allows the first and second moving means to move independently of each other, and when locked, prevents the first and second moving means from moving independently of each other.

[0021] In one embodiment of the first aspect, the first and / or second moving means are rotationally moveable.

[0022]

[0022] In one embodiment of the first aspect, the first and / or second moving means are rotationally movable around the rotation axis, the first and / or second moving means have an outward facing surface that circumscribes the rotation axis, and the stent guidewire and / or stent pusher are wound on the outward facing surface of the first and / or second moving means.

[0023] In one embodiment of the first aspect, the first and / or second moving means is a structure having a circular cross section, and the stent guidewire and / or the stent pusher are wound around the outside of the structure.

[0024] In one embodiment of the first aspect, the structure having a circular cross-section is a wheel, a spool, a reel, a bobbin, a drum, or a functional equivalent thereof.

[0025] In one embodiment of the first aspect, the rotation axes of the first and second moving means are coincident.

[0026] In one embodiment of the first aspect, the apparatus is configured such that the first and / or second moving means are movable manually or by a mechanism comprising a motor, a biasing means or a spring.

[0027] In one embodiment of the first aspect, the device is configured to limit an insertion distance of a stent guidewire and / or a stent pusher movable by the first and / or second moving means.

[0028] In one embodiment of the first aspect, the device is configured such that the limit on the insertion distance of the stent guidewire and / or the stent pusher movable by the first and / or second moving means is adjustable.

[0029]

[0029] In one embodiment of the first aspect, the stent guidewire and / or stent pusher include a locking member or mechanical mechanism configured to limit the insertion distance, the locking member or mechanical mechanism configured to limit the movement of the first and / or second moving means.

[0030] In one embodiment of the first aspect, the device comprises an output port, and the stent guidewire and stent pass through the output port.

[0031] In one embodiment of the first aspect, the output port communicates with the elongate structure, and a stent guidewire and a stent pass through the elongate structure.

[0032] In one embodiment of the first aspect, the elongate structure is configured to be introduced into the subject's body via a natural or artificially created body orifice.

[0033] In one embodiment of the first aspect, the elongate structure is configured to be passed through the male or female urethra into the bladder.

[0034]

[0034] In one embodiment of the first aspect, the elongated structure comprises an electro-optical imaging device and an illumination device configured to illuminate a field covered by the imaging device.

[0035]

[0035] In one embodiment of the first aspect, the apparatus comprises a wired or wireless interface configured to transmit image-encoded signals from the imaging device to an electronic device comprising a visual display screen.

[0036] In one embodiment of the first aspect, the electronic device comprising the visual display screen is separate or not integral with the apparatus.

[0037]

[0037] In one embodiment of the first aspect, the electronic device with a visual display screen is a mobile device, a smartphone, a tablet computer, a laptop computer, or a desktop computer.

[0038]

[0038] In one embodiment of the first aspect, the mobile device, smartphone, tablet computer, laptop computer, or desktop computer includes software instructions stored in memory for receiving and decoding image-encoded signals from an imaging device and displaying the encoded images on an electronic device having a visual display screen.

[0039]

[0039] One embodiment of the first aspect includes a stent disposed about the guidewire and operatively associated with the stent pusher.

[0040] In one embodiment of the first aspect, the stent is configured to be placed in a fluid conduit of a body.

[0041] In one embodiment of the first aspect, the fluid conducting body is a ureter.

[0042]

[0042] In one embodiment of the first aspect, the stent has a portion biased into a nonlinear configuration, the guidewire maintains the linear configuration of the portion, and withdrawing the guidewire from the stent enables the portion to assume the nonlinear configuration.

[0043] In one embodiment of the first aspect, the stent is a double J ureteral stent.

[0044] In one embodiment of the first aspect, the apparatus comprises a housing.

[0045] In one embodiment of the first aspect, the housing provides a handle or gripping surface.

[0046]

[0046] In one embodiment of the first aspect, the housing provides a holder for holding the mobile device.

[0047] In a second aspect, the present invention provides a method for inserting a stent into a body structure of a subject, comprising: Providing an apparatus according to any embodiment of the first aspect; Introducing a stent guidewire and a stent into a body of a subject; operating a first moving means to move the stent guidewire until a distal end is located in or about a subject's body structure requiring stent placement; and operating a second moving means for moving the stent pusher relative to the stent guidewire, independent of the stent guidewire, to push the stent until a distal end is located in or about the body structure requiring stenting. The present invention provides a method comprising:

[0048] In a third aspect, the present invention provides a method for inserting a stent into a body structure of a subject, comprising: Providing an apparatus of any embodiment of the first aspect, wherein a stent guidewire and a stent pusher are configured to be movable together in an interdependent manner; disposing a stent over the stent guidewire; Introducing a stent guidewire and a stent into a body of a subject; operating a first moving means to move the stent guidewire towards the subject's body structure in need of stenting until a distal end of the stent guidewire is located within or around the subject's body structure in need of stenting; and operating a second moving means for moving the stent pusher relative to the stent guidewire, independent of the stent guidewire, to push the stent until a distal end is located in or about the body structure requiring stenting. The present invention provides a method comprising:

[0049]

[0049] In one embodiment of the third aspect, the method includes operation of a first moving means to withdraw the stent guidewire from the stent while allowing the stent to remain in or around the body structure where stent placement is required. [Brief description of the drawings]

[0050] [Figure 1] 1 shows an exploded view of a highly preferred apparatus of the present invention, the apparatus is not necessarily complete, but shows the components necessary for basic operation. [Figure 2A] FIG. 1 shows the marked cross section A-A'. [Figure 2B] A reproduction of FIG. 2A, but with internal components removed to more clearly show the structure of the plug. [Figure 3A] A particularly preferred device of the present invention is shown in side view. [Figure 3B] FIG. 3B is a rear view of the embodiment of FIG. 3A. [Figure 3C] Three successive views are shown demonstrating the operation of the latch mechanism. [Figure 4A]The radially movable tabs are shown each in a disengaged position such that they are unable to contact the locking member. The inset shows tab "T" moved to an engaged position such that it is able to contact the locking member. [Figure 4B] The radially movable tabs of FIG. 4A are shown in perspective view to more clearly show each of the orthogonally extending walls.

[0051]

[0058] Unless otherwise indicated, features in the drawings labeled with the same number are intended to be the same feature, or at least functionally similar feature, when used across different drawings.

[0052]

[0059] The drawings are not prepared to any particular scale or dimensions, and are not intended as completely accurate representations of the various embodiments.

[0053]

[0060] After reviewing this description, it will be apparent to those skilled in the art how the present invention may be implemented in various alternative embodiments and alternative applications. However, while various embodiments of the present invention are described herein, it is understood that these embodiments are presented by way of example only, and not limitation. Thus, this description of various alternative embodiments should not be construed as limiting the scope or breadth of the present invention. Furthermore, statements regarding advantages or other aspects apply not necessarily to all embodiments, but to specific exemplary embodiments, or indeed to any embodiment covered by the claims.

[0054]

[0061] Throughout the description and claims of this specification, the words "comprise" and variations of words such as "comprising" and "comprises" are not intended to exclude other additional elements, components, integers or steps.

[0055]

[0062] References throughout this specification to "one embodiment" or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" and "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may.

[0056]

[0063] As used herein, unless otherwise indicated, relative terms such as "proximal" and "distal" are used as points of reference when used with the devices of the present invention. Thus, the term "proximal" means closer to the device and "distal" means further from the device.

[0057]

[0064] As used herein, the terms "displace," "displacement," and similar terms, when used in reference to a guidewire or stent pusher, mean that the distal end of the guidewire or stent pusher is moved.

[0058]

[0065] When a structure or combination or arrangement of structures is described as being "configured" to perform a certain function, the configuration may be in terms of any one or more of the following: shape, size, orientation, material of manufacture, weight, flexibility, elasticity, deformability, resistance, rigidity, softness, roughness, smoothness, torsion, heat resistance, cold resistance, conductivity (thermal or electrical), resistance to conduction (thermal or electrical), or any other parameter apparent to one of ordinary skill in the art that seeks a required functional result. The term "configured" may also refer to non-physical parameters, such as the use of computer program instructions for a hardware item to provide a certain function.

[0059]

[0066] The present invention is anticipated based at least in part on the inventors' discovery that insertion of stents, particularly ureteral stents, is improved when a device capable of independently moving the guidewire and stent pusher is used. In some embodiments, the device is configured to move the guidewire and stent pusher together. Use of the device simplifies the process of stent insertion, as the clinician inserting the stent is not required to manually manipulate the wire and stent pusher independently or together. It is proposed that stent insertion, particularly ureteral stent insertion, is within the capabilities of a non-specialist clinician when the device is used.

[0060]

[0067] In other embodiments, the device is configured to allow the guidewire and / or stent to be moved distally only a certain amount before being stopped. The clinician is not required to use judgment regarding how far the guidewire and / or stent are advanced into the subject during a stent insertion procedure. Again, with regard to use of the present device, it is suggested that stent insertion, and in particular ureteral stent insertion, is within the capabilities of a non-specialist clinician.

[0061]

[0068] It is further proposed that use of the device obviates the need for imaging equipment to visualize the path of the guidewire and / or stent to, through, or into a body structure in order to assume the required location. For example, if the stent is a ureteral stent, the clinician can advance the guidewire and distal end of the stent into the renal pelvis using only simple manipulation of the device without the need for fluoroscopic guidance.

[0062]

[0069] The device allows the guidewire and stent to be advanced together in a distal direction. As will be appreciated by those skilled in the art, the stent is moved relative to the wire using a pusher, as known in the art. The pusher is separate from the stent and functions to contact the proximal end of the stent, so that when the pusher is moved distally by the device, the stent is also moved distally. When the clinician is advancing the guidewire and stent to a desired location in the subject's body, such as the ureter, it is required that the guidewire and stent pusher (and therefore the stent) move together.

[0063]

[0070] The device allows for movement of the guidewire relative to the stent, the stent remains in place (by locking the stent pusher) at the desired destination in the subject's body (such as the ureter), and the guidewire is withdrawn from within the stent back into the device.

[0064]

[0071] The invention will now be explained in more detail with reference to the non-limiting examples shown in the drawings.

[0065]

[0072] First, referring to the exploded view of Figure 1, which shows a device (10) according to a preferred embodiment of the present invention, the device comprises a first spool (15) (which is a first moving means), a second spool (20) (which is a second moving means), and a housing (25).

[0066]

[0073] A guidewire (30) is secured to and wound around first spool (15). As will be described, guidewire (30) is seated within a channel (40) formed in the outer peripheral surface of first spool (15). The distal end of guidewire (30) is advanced distally upon counterclockwise (as shown) rotation of first spool (15).

[0067]

[0074] The first spool (15) is sized to fit within a circular bore (45) formed in the second spool (20) to allow the first spool (15) to rotate within the bore (45) while preventing any material misalignment of the rotational axes of the first spool (15) and second spool (20). The guidewire (30) is seated within the channel (40) and therefore does not contact the inner circumferential surface of the bore (45).

[0068]

[0075] The first spool (15) and the second spool (20) share a common axis of rotation (50) and are capable of rotating about the axis (50) relative to one another.

[0069]

[0076] Guidewire (30) extends from first spool (15) through a passageway (55) formed in second spool (20) to second spool (20). After exiting passageway (55), the guidewire enters passageway (55) formed in second spool (20). Note that passageway (55) forms a shallow angle with respect to a tangent formed with the inner peripheral surface of bore (45) to limit bending of guidewire (30) as it exits passageway (55) and transitions into channel (60).

[0070]

[0077] The guidewire (30) is wound around the second spool (20) and resides within the channel (60). At one point, the guidewire enters the lumen of a pusher (65) that is coaxial with the guidewire. The pusher (65) is fixed to the second spool (20). The distal end (66) of the pusher (65) is advanced distally upon counterclockwise (as shown) rotation of the second spool (20).

[0071]

[0078] The second spool (20) seats within the space (70) of the housing (25). The pusher (65) (containing the guidewire (30)) seats within the groove (60) and therefore does not contact the circumferential inner surface of the space (70).

[0072]

[0079] The first spool (15) and second spool (20) are capable of independent rotation relative to each other and relative to the housing (25), which is typically held by the clinician at the handle (75) and therefore remains stationary while the first spool (15) and / or second spool (20) are rotated.

[0073]

[0080] Pusher (65) (containing guidewire (30)) leaves second spool (20) through a passageway (not shown) formed in housing (25). The path of the passageway is indicated by dashed line (80).

[0074]

[0081] The pusher (65) (containing the guidewire (30)) passes from the passageway (80) into the lumen of an elongated structure in the form of a proboscis (85). The stent (90) also passes through the lumen of the proboscis (85). The proboscis (85) is depicted in cut-away form. In practice, the proboscis is long enough to allow its distal end to be close enough to the location within the body that will receive the stent. For example, if the device is for delivery of a ureteral stent, the proboscis must be long enough to pass through the ureter until the distal end of the proboscis (85) is within the bladder.

[0075]

[0082] The proboscis (85) is typically rigid or semi-rigid to allow the clinician to change the position of the end of the proboscis (85). For example, if the device is for the insertion of a ureteral stent, the clinician can change the angle of the proboscis (85) until the end of the proboscis (85) is pointed toward the opening of the ureter where the stenting will occur. Alternatively, the proboscis (85) may be flexible but "steerable" using mechanisms known to those skilled in the art.

[0076]

[0083] The proboscis (85) may include a termination plug (86) that fits snugly into the proboscis (85). Further details of the structure and its arrangement relative to other components of the device can be seen in Figure 2A, which is a cross-sectional view through line A-A' of Figure 1. Figure 2B shows the termination plug (86) alone to more clearly demonstrate the structure.

[0077]

[0084] Termination plug (86) has a first axial space (87) that receives a video camera with integrated LED light (88) that allows visualization of the internal anatomical structures of the subject's body. Power input and signal output wires (not shown) for the camera and light (88) pass through the rear of the termination plug and through the proboscis (85) lumen to a power source (not shown) and electronics (not shown) held in a cavity within the device case just prior to the proximal end of proboscis (85).

[0078]

[0085] End plug 86 has a second axial space 89 that accommodates guidewire 30 and stent 90 (before the stent is deployed). In the cross-sectional view of Figure 2A, stent pusher 65 is not visible because it is located behind stent 90.

[0079]

[0086] The end plug has third and fourth axial spaces (91a, 91b) that allow the passage of flushing fluid from inside the proboscis (85) lumen to the exterior area proximal to the camera and light (88). As discussed below, flushing fluid may be used to clear out any suspended solids that interfere with the camera's vision.

[0080]

[0087] If the device is being used for ureteral stenting, the camera and light (88) are used by the clinician to visualize the inner surface of the bladder and locate the ureteral opening. Once located, the distal end of the proboscis is approximated to the ureteral opening to allow for the insertion of a stent (90) held within the proboscis (85). A guidewire (30) is inserted through the stent (90) while within the proboscis (85).

[0081]

[0088] Urine in the bladder may be cloudy with insoluble suspended matter, such as blood, casts, crystals, tissue debris, microbial colonies, etc. Therefore, some means of flushing such matter from the camera (88) lens to improve visibility is desirable. To that end, the device (10) may include a port (100) for passing a flushing fluid through the proboscis (85) lumen. The fluid will proceed through the device (10) via the port (100) under gravity or by some active transport means to the end of the lumen (85) where it will exit primarily via the third and fourth axial spaces (91a, 91b). As will be appreciated, the fluid used for flushing must be biocompatible, with sterile normal saline being generally preferred.

[0082]

[0089] The first spool (15), the second spool (20) and the housing (25) are typically maintained in relative mutual position by some additional components (not shown). For example, the housing (25) may be provided with tabs extending onto the forwardly presented faces of the first spool (15) and the second spool (20) (as shown). The tabs prevent disengagement of the components (15), (20), and (25) of the device (10) while allowing rotation of the first spool (15) and the second spool (20). As another example, additional housing parts are provided that complement the housing (25) and fit onto the forwardly presented faces of the housing (25) (as shown). Again, the additional housing parts do not substantially impede rotation of the first spool (15) and the second spool (20).

[0083]

[0090] In the preferred embodiment of the drawings, the first spool (15) and the second spool (20) are maintained in a coaxial rotational relationship with one another due to the close fitting characteristics of the components. Other alternatives are available, such as the use of an axis extending through the centers of the first spool (15) and the second spool (20).

[0084]

[0091] The device (10) may be configured such that the first spool (15) and / or the second spool (20) are manually rotatable. To facilitate manual rotation, the first spool (15) and / or the second spool (20) may be provided with one or more holes or recesses for receiving fingers or thumbs of a hand or other part. Alternatively, the first spool (15) and / or the second spool (20) may be provided with one or more protrusions for facilitating engagement with fingers or thumbs of a hand or other part. In another alternative, a crank may be provided for turning the first spool (15) and / or the second spool (20).

[0085]

[0092] As an alternative to manual rotation, the device may include a small electric motor configured to rotate the first spool 15 and / or the second spool 20. The motor may transmit the rotational motion of its shaft to the spools 15, 20 via a gear arrangement. The motor may be a stepper motor configured to rotate the spools 15, 20 in a controlled manner to limit the chance of damaging the body anatomical structures as the stent guidewire 30 and stent 90 are advanced.

[0086]

[0093] The first spool (15) and the second spool (20) may be independently rotatable, in which case no modification of the illustrated embodiment would be required, for example, if the guidewire (30) is to be withdrawn from within the stent (90).

[0087]

[0094] In some situations, it may be desirable to lock the first spool (15) and the second spool (20) together. Such action is required, for example, when the guidewire (30) and the stent (90) are advanced together into the body to place the stent (90) at a desired location in the body. The spools (15) and (20) may be locked together by a simple U-shaped pin, the first leg of which is inserted into an aperture formed in the first spool (15) and the second leg of which is inserted into an aperture formed in the second spool (20). The pin may be removed to allow independent rotation of the spools (15) and (20).

[0088]

[0095] The device 10 may be configured to prevent further rotation of the first spool 15 and / or second spool 20 once a predetermined length of the stent guidewire 30 or stent 90 has been advanced into the body. For example, if the device 10 is for the insertion of a ureteral stent, the rotation of the first spool 15 and second spool 20 may be stopped after a length of the stent guidewire 30 or stent 90 has exited the device 10 that matches the expected or known length of the target ureter. The use of some type of locking mechanism may prevent insertion of too much of the stent 90 into the ureter (or other body structure), thereby avoiding tissue damage or over-insertion into the ureter, and thus preventing the coiled end from becoming anchored in the bladder.

[0089]

[0096] The locking mechanism may be embodied as a simple mechanical device. For example, a first locking member may extend from the housing (25) and a second locking member may extend from the spools (15)(20), where the first and second locking members collide when the spools (15)(20) rotate a predetermined amount. One of the locking members may be movable and lockable in place to adjust the length of the guidewire (30) and stent (90) exiting the device (10). Such adjustment may be required according to the subject's anatomical characteristics, such as ureteral length.

[0090]

[0097] When the spools 15, 20 are rotated by a stepper motor, the stepper motor may function to limit rotation according to data entered by the clinician, and thus the length of the guidewire 30 and stent 90 introduced into the subject. As will be appreciated, the stepper motor requires command by a microprocessor that may be integral to the device 10 or located remotely.

[0091]

[0098] Further locking mechanisms may be electronic in nature and function to monitor the length of the stent 90 or stent pusher 65 or guidewire 30 advanced from the device 10. For example, the device 10 may include rollers configured to output a digital or analog signal regarding the number of revolutions the rollers have turned. The stent 90 or stent pusher 65 or guidewire 30 advanced from the device 10 turns the rollers and thus a calculation or inference can be made regarding the length advanced. Once a predetermined length has been achieved, a locking mechanism (such as a solenoid actuated clamp) may be activated or an audible warning signal may be given. Again, a microcontroller is required to enable these functions.

[0092]

[0099] The length of the extended guidewire (30) can vary, but in a preferred embodiment, the proximal end of the stent (90) will extend the same distance, i.e., to the end of the proboscis (85). The stent (90) will be advanced the same distance from its starting position, regardless of any limitations on the rotation of the first spool. Thus, by way of example only, if the guidewire (30) is advanced 30 cm, the stent (90) will be advanced another 30 cm (60 cm total). As another example, if the guidewire (30) is advanced only 15 cm, the stent (90) will be advanced an additional 45 cm (60 cm total). In any event, at the end of the stent insertion process, the proximal end of the stent (90) will be flush with the end of the proboscis (85).

[0093]

[0100] In some embodiments, the device 10 comprises means for connecting a video camera in the proboscis 85 to a screen capable of displaying the video stream captured by the camera. Preferably, the display screen is provided by a mobile device, such as a smartphone (Android™, iOS™, etc.) or a tablet computing device (Windows™, Linux™, Android™, iOS™, etc.). The device 10 can therefore provide an interface for connecting the mobile device to the device 10. The interface may be a wired interface (such as a USB interface) or a wireless interface (such as a Bluetooth™ or WiFi™ interface).

[0094]

[0101] Where the operation of the apparatus requires a microprocessor for operation, the microprocessor may be provided by the mobile device Data exchange between the apparatus and the mobile device may be achieved by wired or wireless means as detailed above.

[0095]

[0102] If the operation of the device requires data input (e.g., input of ureteral length), the mobile device may act as a user interface. If the operation of the device involves data output (e.g., length of the stent advanced by the device), data exchange between the device and the mobile device may be accomplished by wired or wireless means as detailed above.

[0096]

[0103] Use of a mobile device in combination with the apparatus typically requires that the device has application software installed on the device. The software is typically configured to facilitate connectivity and data exchange between the mobile device and the apparatus. The application software may be further configured to retrieve subject data from the remote database that allows for subject identification, or details of previously measured ureteral length, or estimated ureteral length. The application software may be configured to allow new subjects to be added to the remote database by a clinician.

[0097]

[0104] The clinician may further be enabled by the application software to add information to a new or existing subject entry in the remote database, such as required follow-up actions, including stent removal. Such entries may have a date component, such as the date of stent removal. The application software (or another item of software) may be configured to output a message on the date recorded in the database, such as a push notification, email or SMS text message, as a reminder that a follow-up action is required. Although not common, it is possible that the presence of a ureteral stent in a subject may be forgotten.

[0098]

[0105] The application software may enable the entry of subject contact details in a remote database. The subject contact details, such as a mobile phone number, email address, or messaging app address, to name a few, may enable electronic contact. The application software (or another item of software) may deliver educational materials or appointment reminders to the subject's device.

[0099]

[0106] The application software may be configured to obtain informed consent from a client in connection with a proposed stent insertion procedure. The application software may be configured to firstly output information required for informed consent and secondly accept as input from the subject a confirmation that the subject understands the information and agrees to the stent insertion procedure. Such input / output may be by way of a graphic user interface.

[0100]

[0107] The device 10 may provide a means for holding a mobile device on or about the device 10. Typically, the holding means is positioned such that the display screen of the mobile device faces away from the proboscis 85 and is easily viewable by the clinician as the clinician advances the proboscis into the subject. Suitable holding means include brackets, pockets, recesses, clamps, one side of a hook-and-loop fastener attachment means, magnets, pressure sensitive adhesives, and the like.

[0101]

[0108] Having now described the device, attention is now directed to its operation, which will be described with reference to a preferred application, which is ureteral stent insertion.

[0102]

[0109] The device 10 is depicted in the state required to begin a ureteral cannulation procedure. The guidewire 30 is completely within the proboscis 85, with its distal end at the distal end of the proboscis 85. The distal end of the stent 90 has been retracted a distance from the distal end of the guidewire 30, thereby exposing the distal portion of the guidewire 30. The distance may be predetermined and may be greater than about 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 cm. In some embodiments, the distance is in the range of about 20 cm to about 30 cm.

[0103]

[0110] The clinician inserts the prosthesis (85) into the subject's ureter and advances the distal end into the bladder. Under visual control (i.e., with the assistance of a video camera at the distal end of the prosthesis (85)), the clinician visualizes the opening of the affected ureter and manipulates the prosthesis so that the distal end of the prosthesis is adjacent to and oriented toward the opening of the ureter. The first spool (15) and the second spool (20) are joined at their junction such that as the clinician rotates the first spool (15), the second spool (20) is rotated in the same direction, first advancing the exposed distal portion of the guidewire (30) into the ureter and advancing the stent (90) toward the end of the prosthesis (85). Rotation of the first spool 15 and the second spool 20 continues such that the stent 90 and the guidewire 30 are advanced together into the ureter until the distal end of the guidewire 30 is positioned within the renal pelvis. The appropriate location may be estimated according to the subject's predicted ureteral length, or alternatively, may be estimated by imaging techniques such as fluoroscopy or ultrasound.

[0104]

[0111] In some embodiments, the device includes a stop that prevents further rotation of the first spool (15) to prevent further advancement of the guidewire (30) beyond a predetermined distance. Typically, the predetermined distance is approximately or exactly a known or estimated ureteral length. The second spool (20) is decoupled from the first spool (15) and is therefore independently rotatable to push the stent (90) along the guidewire (30). Rotation of the first spool is prevented by the stop, and thus only the stent (90) is advanced at this stage. Rotation of the second spool beyond a predetermined distance (corresponding to the luminal end of the proboscis (85) and the proximal end of the flattened stent) is prevented by the stop. At that point, the stent (90) is properly positioned, i.e., the distal end of the stent (90) is in the renal pelvis and the proximal end of the stent (90) is in the bladder.

[0105]

[0112] With the stent (90) properly positioned, the guidewire (30) is withdrawn from within the stent (90) by counter-rotating the first spool (15) while the second spool (20) remains stationary. In one embodiment, the first spool (15) and the second spool (20) automatically decouple, leaving the first spool (15) rotatable while the second spool remains stationary, thus allowing the guidewire to be removed and the stent to remain in place within the ureter.

[0106]

[0113] Upon withdrawal of guidewire 30, the distal end of stent 90 assumes a biased coiled configuration, anchoring it within the renal pelvis. When guidewire 30 is fully withdrawn from stent 90, the proximal end of stent 90 also assumes a biased coiled configuration, anchoring it in place within the bladder.

[0107]

[0114] The guidewire 30 is withdrawn until its distal end is within the proboscis 85. The clinician then withdraws the proboscis 85 through the ureter and removes it from the subject's body.

[0108]

[0115] Turning now to further consideration of a locking mechanism configured to prevent over-rotation of the spool, reference is made to the embodiment of Figures 3A and 3B.

[0109]

[0116] A first locking mechanism is provided by a permanently attached pin (110) extending from the first spool (15). As shown in FIG. 3A, the pin (110) abuts against a locking member (115) and prevents any further clockwise rotation of the first spool (15). This first locking mechanism allows the guidewire (30) to be withdrawn into the proboscis (85), but does not allow the end of the guidewire (30) to be withdrawn through the proximal end of the proboscis (85) and into the housing (25). If the end of the guidewire (30) is unintentionally withdrawn from the proboscis, it may not be possible to reintroduce it into the lumen of the proboscis (85).

[0110]

[0117] A second locking mechanism is provided for the first spool (15). The second locking mechanism allows for the selection of one of three different locking settings based on the subject's estimated ureteral length. Generally, the ureteral length is roughly proportional to the subject's height, and therefore the three settings are referred to as "low", "medium" and "high". The settings are selected by inserting a pin (120) into one of three apertures (125a, 125b, 125c) formed in the first spool (15). Aperture (125a) is selected if the subject is short, aperture (125b) is selected if the subject is medium, and aperture (125c) is selected if the subject is tall. In FIG. 3A, the subject is medium, so the pin (120) is inserted into aperture (125b).

[0111]

[0118] Of course, more than three locking settings may be provided, such as 4, 5, 6, 7, 8, 9, 10 or more. In some embodiments, each locking setting is marked with a numerical indicator. For example, multiple settings in interval length may be used to reflect expected or predicted ureteral lengths (20cm, 22cm, 24cm, 28cm, 30cm, etc.). Alternatively, height ranges may be used to indicate locking settings, such as 150cm-164cm, 165cm-179cm, and 180cm-184cm.

[0112]

[0119] As the first spool (15) is rotated counterclockwise to advance the guidewire (30) into the ureter, the pin (120) moves with the first spool (15) until it contacts the locking member (115). At that point, the first spool (15) cannot be rotated further, thereby preventing an excess length of the guidewire (30) from being advanced into the ureter. As can be appreciated, when the pin (120) is positioned within the aperture (125c), the first spool (15) can be rotated further to allow an additional length of the guidewire (30) to be advanced into the ureter, as may be required for a taller subject having a longer ureter. Similarly, when the pin (120) is set for a shorter subject, only a shorter length of the guidewire can be advanced.

[0113]

[0120] An alternative to the pin and aperture configuration detailed above is shown in Figures 4A and 4B. A series of sliding tabs (130a, 130b, 130c) are attached to the first spool at the same circumferential locations as the apertures (125a, 125b, and 125c). The tabs are selected by sliding radially outward as indicated by the superimposed arrow for tab (130c) ("T" = tall).

[0114]

[0121] From FIG. 4B, it can be more easily seen that each tab (130a, 130b, 130c) has a lower wall (135a, 135b, 135c) extending orthogonally therefrom. When tab (130a, 130b, 130c) is not selected, wall (135a, 135b, 135c) is positioned as shown, i.e., distal to the outer edge of first spool (15). When tab (130a, 130b, or 130c) is selected, wall (135a, 135b, or 135c) is moved proximally to the outer periphery of first spool (15), as shown in the inset to FIG. 4A. In the position shown in the inset, wall (135a, 135b, or 135c) may contact a locking member (not shown) extending from the device housing, thereby preventing further rotation. When the tabs (130a, 130b, 130c0) are in their original position (i.e., distal to the outer edge of the spool (15)), contact with the locking member is not possible, thus allowing further rotation.

[0115]

[0122] Of course, an alternative feature would be to allow the tabs to be selected by sliding radially inward, so long as the position of the step members is properly positioned.

[0116]

[0123] Proceeding to Figure 3B, reference is made to a latch mechanism comprising a pin (140) extending from a second spool (20) and a pin lock (145) on the opposite side of the device (10). The latch mechanism catches and locks the second spool (20) to prevent rotation in either direction. This lock allows the first spool (15) to rotate in the opposite direction to retrieve the guidewire (30) while the second spool (20) remains stationary, leaving the stent (90) and stent pusher (65) in place.

[0117]

[0124] The embodiment of Figures 3A and 3B will now be described by reference to a typical course of operation by a clinician.

[0118]

[0125] As explained above, the proboscis (85) is inserted into the bladder via the ureter. Once the distal portion of the guidewire (30) is inserted into the ureteral orifice, the clinician grasps the second spool (20) around the spokes (marked 22). The second spool (20) is rotated counterclockwise by the clinician. Simple frictional forces hold the first spool (15) and second spool (20) together, causing the first spool (15) to rotate with the second spool (20). Assuming both spools (15, 20) are rotating, the guidewire (30), stent pusher (65) and stent (90) are all advanced together at the same speed out of the proboscis (85) and into the ureter. When the guidewire (30) is extended as far as possible (governed by any locking mechanism that prevents further rotation of the first spool (15)), only further rotation of the second spool (20) is still permitted because the frictional forces between the spools (15, 20) are overcome by the clinician continuing to turn the second spool (20). Further rotation causes the stent pusher (65) to push a short portion of the distal end of the stent (90) past the distal end of the guidewire (30).

[0119]

[0126] Rotation of the second spool (20) is eventually stopped by the latch mechanism. In particular, the pin (140) deforms the flexible portion (140a) of the pin lock (140) as the second spool (20) is rotated. Rotation is stopped by the pin (140) contacting the surface (140b), at which point the flexible portion (140a) returns to its original position, thereby trapping the pin (140). Now the second spool (20) is fixed, and the clinician can rotate the first spool (15) in the opposite direction to withdraw the guidewire (30), while keeping the stent (90) and stent pusher (65) in place. Withdrawal of the guidewire (30) allows the stent (90) to assume a coiled configuration at each end.

[0120]

[0127] The embodiments of the invention described thus far do not require the first and second spools to rotate more than one full turn to move the guidewire or stent pusher the required distance (either proximally or distally). In an alternative embodiment of the invention, one or both of the spools may be operable such that multiple turns are required. Typically, both spools are operable such that multiple turns are required. In this alternative embodiment, the radii of the spools may be significantly smaller than those of the devices described herein.

[0121]

[0128] Each of the spools is generally barrel-shaped and is arranged in a nested fashion with one spool seated inside the other. The spools are threadably engaged with one another such that one can be rotated independently of the other. To facilitate manual rotation, each spool may have a gripping structure that allows fingers to engage the spool. The gripping structure may further allow one spool to be held stationary while the other is rotated.

[0122]

[0129] As an alternative to manual operation, one or both spools can be rotated by a motor (such as a stepper motor) under the control of a processor having access to software instructions, in which case the spools may be formed with teeth or grooves, for example, to allow the spools to be driven by the motor. The software instructions can prevent either spool from being over-rotated, thus eliminating the need for any physical locking devices.

[0123]

[0130] Compared to the depicted embodiment having a single groove on each spool, each of the spools may include two starting helical grooves. The spools are arranged in a nested fashion, with the inner spool grooved to accommodate the guidewire and the outer spool grooved to accommodate the stent and stent pusher. The second starting helical groove on each spool may take the form of an ACME thread or similar to transfer the wire from the inner spool to the outer spool and also provide the lateral force needed to transfer the guidewire and stent and stent pusher to the prosthesis.

[0124]

[0131] As will be appreciated, some or most or all of the components of the device may be manufactured from medical grade materials that are also sterilizable. The housing of the device mat is typically sealed and not openable by the user. Typically, the device is intended for single use only.

[0125]

[0132] The present invention has been described in detail primarily with reference to an apparatus for the insertion of ureteral stents. The invention is not to be construed as being limited to the apparatus and method of its use. Given the benefit of this specification, those skilled in the art will routinely devise other uses and will further devise modifications to the depicted embodiments and their descriptions that can facilitate other uses.

[0126]

[0133] Various features of the present invention are described with reference to the drawings, and in particular with reference to the numbered components of the drawings. It is contemplated that any component of the drawings may be taken out of the context of the depicted embodiment and may be used in combination with embodiments different from those depicted. For example, features of the depicted embodiments may be combined with any feature defined in the Summary of the Invention section, the Detailed Description section, or the claims herein.

[0127]

[0134] Those skilled in the art will appreciate that the invention described herein is susceptible to further variations and modifications other than those specifically described, and it is understood that the invention includes all such variations and modifications falling within the spirit and scope of the invention.

[0128]

[0135] While the present invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art.

[0129]

[0136] Accordingly, the spirit and scope of the present invention is not intended to be limited to the above examples, but is to be understood in the broadest sense permitted by law.

Claims

1. A device for inserting a stent into a body structure of a subject, the device having a proximal end and a distal end: a first movable structure; a second movable structure; a stent guidewire having a distal end and at least a portion of which is wound around the first movable structure; a stent pusher having a distal end and at least a portion of the stent pusher wrapped around the second movable structure; An apparatus operable to distally advance the distal end of the stent guidewire and the distal end of the stent pusher to deploy a stent.

2. The device described in claim 1, wherein the first movable structure and the second movable structure are configured to be connected to each other so as to unwind the stent guide wire and the stent pusher from the first movable structure and the second movable structure, respectively.

3. The device described in claim 2, comprising a locking mechanism configured to switch between locking the first movable structure and the second movable structure to each other so that the stent pusher is movable relative to the stent guide wire, and unlocking the first movable structure and the second movable structure so that the stent guide wire and the stent pusher are movable in a mutually dependent manner.

4. The device described in claim 1, wherein the first movable structure and the second movable structure are independently stoppable or lockable to prevent movement in a certain direction.

5. The device described in claim 1, wherein the first and / or second movable structures have circular cross-sections, and the stent guide wire and / or the stent pusher are wound around the periphery of each structure.

6. The device described in claim 1, wherein the first movable structure and the second movable structure are arranged in a nested manner.

7. The device described in claim 6, wherein the guide wire passes through a passage formed in the second movable structure.

8. The device described in claim 7, wherein the guide wire enters the lumen of the stent pusher.

9. The device described in Claim 6, wherein the first and / or second movable structures have respective axes of rotation, and the axes of rotation of the first and second movable structures are coincident.

10. The device described in claim 1, wherein the first and / or second movable structures are configured to be movable by hand or by a mechanism including a motor, a biasing means, or a spring.

11. A device for inserting a stent into a body structure of a subject, the device having a proximal end and a distal end: a stent guidewire having a distal end and at least a portion of the stent guidewire wound around the first movable structure; a stent pusher at least partially wrapped around the second movable structure; an apparatus operable to move the first and second movable structures to distally advance the distal ends of the stent guidewire and the stent pusher to deploy a stent.

12. The device of claim 11, configured to limit the insertion distance of the stent guidewire and / or the stent pusher.

13. The device described in claim 11, further comprising a locking portion for limiting rotation of the first movable structure, thereby limiting the insertion distance of the stent guide wire by the first movable structure.

14. The device described in Claim 13, wherein the locking portion is adjustably positioned.

15. The device described in claim 13, wherein the first movable structure and the second movable structure are connected to each other by friction until the first movable structure is stopped by the engaging portion, at which point the connection between the first movable structure and the second movable structure is released.

16. The device described in claim 13, comprising a locking member or mechanical mechanism configured to limit the insertion distance of the stent pusher by limiting the rotation of the second movable structure.

17. The device described in claim 16, wherein the first movable structure is rotatable to withdraw the guide wire while the second movable structure is locked.

18. The apparatus of claim 11, further comprising an electronic optical imaging device and an illumination device configured to illuminate a field of view covered by the imaging device.

19. The apparatus of claim 18, comprising a wired or wireless interface configured to transmit image-encoded signals from the imaging device to an electronic device comprising a visual display screen.

20. The apparatus of claim 19, wherein the electronic device having a visual display screen is separate from or not integrated with the apparatus and comprises a mobile device, a smartphone, a tablet computer, a laptop computer, or a desktop computer.

21. The apparatus described in claim 20, wherein the mobile device, smartphone, tablet computer, laptop computer, or desktop computer has software instructions in its storage memory for receiving and decoding image-encoded signals from the imaging device and displaying the encoded images on the electronic device having a visual display screen.

22. The device of claim 11, further comprising a ureteral stent disposed around the guide wire and operably associated with the stent pusher.

23. An apparatus for inserting a stent into a body structure of a subject, the apparatus having a proximal end and a distal end: a stent guidewire having a distal end and at least a portion of the stent guidewire wound around the first movable structure; a stent pusher at least partially wrapped around the second movable structure; the second movable structure is movable relative to the first movable structure to unwind the stent pusher from the second movable structure and advance the stent pusher distally along the stent guidewire.

24. The device described in claim 23, wherein the first movable structure and the second movable structure are configured to be connected to each other so that the distal end of the stent guide wire and the distal end of the stent pusher advance in a distal direction.

25. The device described in claim 23, wherein the first movable structure is configured to move relative to the second movable structure to pull out the stent guide wire.

Images