Ureteral access sheath for insertion in the ureter of a human or animal patient

Abstract

The invention relates to a ureteral access sheath (10) for insertion in the ureter (56) of a human or animal patient, wherein the access sheath (10) has, at a proximal end, an introduction portion (16) for a medical instrument and has an elongate portion (18) which extends from the proximal introduction portion (16) to a distal end (12) of the access sheath (10), wherein the elongate portion (18) comprises, over at least substantially the length of the elongate portion (18), at least one lumen (20) for guiding through the medical instrument. According to the invention, at least in some regions along the elongate portion (18), an elastically deformable cover element (22) is arranged on an outer wall of the lumen (20), wherein the cover element (22) can be deformed between a basic position, in which the cover element (22) rests against the outer wall of the lumen (20), and a guide-wire position, in which the cover element (22) is moved away from the outer wall of the lumen (20) by a guide wire (24) and forms a guide channel (26) for the guide wire (24).

Description

[0001] Ureteral access sheath for insertion into a ureter of a human or animal patient >

[0002] DESCRIPTION:

[0003] The present invention relates to a ureteral access sheath for insertion into a ureter of a human or animal patient.

[0004] A ureteral access sheath (UAS), also known as a ureteral stent or ureteral stent, is a medical device that is inserted into the ureter of a human or animal patient. The ureteral access sheath (UAS) is used, for example, during ureterorenoscopy (URS) to facilitate the passage of a ureterorenoscope (URS) through the urinary tract into the kidney. A UAS typically consists of an elongated section with a distal tip and a proximal insertion section with an insertion funnel. For the purposes of this disclosure, "proximal" refers to areas closer to the treatment staff, while "distal" refers to areas closer to the patient's body center. The entire UAS is inserted into the urinary tract over a pre-inserted guide wire (GW).After the distal tip of the UAS reaches the kidney, the guidewire and, if present, a dilator unit are removed from the elongated section. The elongated section remains in the body and provides the lumen for the insertion of the ureterorenoscope or other medical devices.

[0005] In some cases, however, the lumen of the UAS becomes blocked during kidney stone removal, making it impossible to remove the ureterorenoscope. In this case, the entire access sheath and ureterorenoscope must be removed from the patient's urinary tract and cleaned. After the blockage is removed, the UAS must be reinserted over a guidewire. However, since the guidewire was removed at the beginning of treatment and could not be reinserted before the UAS was withdrawn due to the blocked sheath lumen, the guidewire must first be reinserted into the urinary tract via a cystoscope.

[0006] This involves considerable additional effort and prolongs the procedure accordingly.

[0007] To address this problem, ureteral access sheaths are known in which the sheath tube is slit, allowing the guidewire to be moved out of the lumen of the UAS and then outside the elongated section. This means that the guidewire no longer blocks the lumen of the sheath tube and therefore does not need to be removed.

[0008] The disadvantage of this solution, however, is that the distal end of the guidewire remains in the kidney and can interfere with the operating room for the medical staff during surgery, for example, when crushing kidney stones with a laser. This interference persists even if the medical staff no longer needs the guidewire.

[0009] It is therefore an object of the present invention to provide a ureteral access sheath which enables improved handling of the guide wire.

[0010] The object is achieved according to the invention with a ureteral access sheath according to claim 1. Advantageous embodiments with expedient further developments are specified in the subclaims.

[0011] A ureteral access sheath (UAS) for insertion into a ureter of a human or animal patient has an insertion portion for a medical instrument at a proximal end and an elongated portion extending from the proximal insertion portion to a distal end of the access sheath, wherein the elongated portion comprises at least one lumen for passing the medical instrument over at least substantially the length of the elongated portion.Improved handling of a guide wire is achieved according to the invention in that an elastically deformable cover element is arranged on an outer wall of the lumen at least in some regions along the elongate section, wherein the cover element is deformable between a basic position in which the cover element rests against the outer wall of the lumen, and a guide wire position in which the cover element is moved away from the outer wall of the lumen by a guide wire and forms a guide channel for the guide wire. In other words, the invention provides that the elongate section, which can also be referred to or designed as a sheath tube or dilator unit, is completely or partially covered with an elastically deformable cover element. In the basic position, this cover element rests as flush as possible against the outer wall without a guide wire, whereby initially no additional space is required orno significantly larger outer diameter is required to provide this additional guide channel. However, due to the elastic deformability, the guide wire can be pushed through between the cover element and the outer wall of the lumen, whereby the cover element is deformed away from the lumen or radially outwards, thereby freeing up the guide channel for the guide wire. The guide wire can thus essentially form its own guide channel by being pushed between the outer wall and the cover element. The elastic deformation of the cover element simultaneously creates a type of restoring force through which the cover element presses the guide wire towards the outer wall of the lumen so that it lies closely against an outer wall of the lumen and can therefore be guided precisely and requires minimal additional space.In the event that the main lumen of the UAS is blocked and the entire UAS must be removed, the UAS of the present invention offers the option of leaving a guidewire in place in the urinary tract. After the UAS has been removed and the blockage in the lumen has been cleared, the entire UAS can be reinserted using this guidewire in the conventional way. Conversely, the guidewire only needs to be inserted into the body when necessary. In cases where the main lumen is not blocked, a guidewire is not required. This means that the treating staff is not forced to have a guidewire in the kidney, which, as already mentioned, can be disruptive during stone fragmentation with a laser or other operations. In summary, the guidewire can be easily removed via the expandable, separate guide channel as long as it is not needed.Should it ever be needed again, it can be reinserted at any time, even if the main lumen is blocked in any way. This allows for safer, time- and labor-saving surgery, even if complications such as a blockage of the main lumen arise.

[0012] In an advantageous embodiment of the invention, the elastically deformable cover element is tubular in shape, at least in some regions, and surrounds the lumen on the outside. In other words, the cover element is designed as a type of elastically deformable tube or elastically deformable cuff and surrounds the entire outer circumference of the main lumen, at least in some regions. As a result, the cover element can be easily pushed over the elongated section for assembly and can be easily removed again, so that the cover element is also suitable as a retrofit solution for existing UAS with only one lumen. The cover element thus has an independent inventive character. Furthermore, the cover element cannot become detached from the sheath tube in this way and can be particularly easily adapted to different UAS types, guidewire types, etc. in terms of material, wall thickness, etc.The tubular shape ensures that the guide wire is reliably guided along the elongated section and remains covered by the cover element before exiting again at the distal end of the UAS.

[0013] Alternatively or additionally, a further embodiment provides that the elastically deformable cover element is at least partially band-shaped, with lateral edges of the cover element preferably being integrally connected to the outer wall of the first lumen. In other words, the cover element is partially or completely designed as a type of band, the lateral edges of which are connected to the outer wall of the main lumen. This is preferably done integrally, for example by gluing, welding, polymerizing, or the like, in order to prevent leaks or detachment. The cover element therefore requires particularly little additional space compared to the elongated section, since its dimensions can be selected to be as small as absolutely necessary to create the guide channel. Furthermore, this can ensure particularly precise guidance of the guide wire.For example, the guide wire can be guided strictly parallel to a central axis of the elongated section.

[0014] Further advantages arise from the elastically deformable cover element being arranged at least predominantly in a groove in the outer wall of the lumen, at least in the basic position. In other words, the outer wall of the main lumen has a groove or recess in which the cover element is received as completely as possible, at least in the basic position, and preferably ends flush with the circumferential contour of the outer wall. As a result, the cover element, at least in the basic position, does not require any additional space and can be fully integrated into the elongated section. In some embodiments, it can be provided that the cover element is also arranged within the groove in the guide wire position and thus does not require or cause an enlarged outer diameter even when the guide wire is in place.

[0015] In a further advantageous embodiment of the invention, the insertion section comprises an insertion funnel for the medical instrument. This facilitates the insertion of a medical instrument into the lumen of the UAS. Alternatively or additionally, the insertion section comprises a port for the guide wire. This allows the guide wire to be inserted or pulled out easily. By preferably arranging the port at an acute angle to a central axis of the elongated section, it is ensured in a structurally simple manner that the guide wire can be automatically guided between the cover element and the outer wall during insertion. Conversely, when the UAS is inserted, the guide wire can be deflected radially outwards from the guide channel and removed from the port.

[0016] In a further advantageous embodiment of the invention, the elongated section comprises or consists of a composite tube that delimits the lumen. In the context of the present disclosure, a composite tube is understood to be a hose- or tubular device that delimits or defines the lumen and consists of two or more interconnected materials. By appropriately selecting the materials and their sequence or arrangement, different properties for the composite tube can be realized particularly easily.

[0017] It has proven advantageous if the composite tube comprises a kink-resistant and / or flexible base tube. The base tube preferably has a volume fraction of more than 50% of the total volume of the composite tube and, through its kink resistance or flexibility, ensures that the UAS can be inserted into a ureter easily and undamaged. Alternatively or additionally, the composite tube is provided with a radial inner layer with a lower coefficient of sliding friction than an adjacent layer. This allows the wall of the lumen to be designed such that a medical instrument can be easily moved through the lumen, regardless of the material of the base tube, and can glide along the inner wall with little effort. The inner layer is preferably made of Teflon or a silicone material.Alternatively or additionally, the composite tube is provided with a radial outer layer against which the cover element rests in the basic position. The outer layer is preferably also made of a material with the lowest possible coefficient of sliding friction, which allows easy insertion of the UAS into a ureter and / or easy movement of the guide wire along the elongated section. The outer layer of the composite tube is partially exposed in the case of a band-shaped cover element; in the case of a tubular cover element, the outer layer can be partially, predominantly, or completely covered by it. Further advantages arise from the elongated section having an atraumatic tip distally. This ensures a reduced risk of complications, since tissue is displaced rather than punctured during insertion of the UAS.

[0018] In a further advantageous embodiment of the invention, a closure device is provided by which the insertion section and the lumen can be closed when the access sheath is not in use. This reliably prevents the penetration of foreign substances, dirt, and the like into the UAS. Preferably, the closure device is connected to the UAS or the insertion section via a detachable clip or snap connection. The closure device can then be easily removed again for use of the UAS.

[0019] In a further advantageous embodiment, it is provided that a guide wire runs through the guide channel and / or that a ureterorenoscope is guided through the insertion section and the elongated section.

[0020] Further features of the invention can be derived from the claims, the figures, and the description of the figures. The features and combinations of features mentioned in the above description, as well as the features and combinations of features mentioned in the following description of the figures or shown alone in the figures, can be used not only in the respectively specified combinations, but also in other combinations without departing from the scope of the invention. Therefore, embodiments of the invention are also to be regarded as encompassed and disclosed which are not expressly shown and explained in the figures, but which emerge from the explained embodiments through separate combinations of features. Likewise, embodiments and combinations of features are to be regarded as disclosed which do not have all the features of an originally formulated independent claim.Furthermore, the above statements are also deemed to disclose variants and combinations of features that go beyond or deviate from the combinations of features described in the backreferences of the claims. They show:

[0021] Fig. 1 shows a schematic longitudinal section through a ureteral access sheath according to a first embodiment;

[0022] Fig. 2 is a schematic cross-section through the ureteral access sheath shown in Fig. 1;

[0023] Fig. 3 is a schematic perspective view of a proximal end region of the ureteral access sheath according to another embodiment;

[0024] Fig. 4 is a side view of the ureteral access sheath according to another embodiment with a closure device;

[0025] Fig. 5 is a perspective view of a distal end portion of the ureteral

[0026] Access sheath according to Fig. 4, wherein a guide wire is moved towards the distal end region;

[0027] Fig. 6 is a perspective view of the distal end portion of the ureteral access sheath according to Fig. 5, wherein one end of the guide wire in the distal end portion is moved out of a guide channel; and

[0028] Fig. 7 is a schematic representation of a kidney in whose ureter a ureteral access sheath according to the invention and a guide wire are arranged.

[0029] Fig. 1 shows, according to a first embodiment of the invention, a schematic longitudinal section through a ureteral access sheath 10 (UAS) in the region of its distal end 12. Fig. 1 is explained below in conjunction with Fig. 2, which shows a schematic cross section according to the sectional plane AA through the UAS 10 shown in Fig. 1. The UAS 10 is used for insertion into a ureter 56 (see Fig. 7) of a human or animal patient and has, at a proximal end 14 (see Fig. 3), an insertion section 16 for a medical instrument, in particular for a ureterorenoscope (not shown), as well as an elongate section 18 which extends from the proximal insertion section 16 to the distal end 12, wherein the elongate section 18 comprises at least one lumen 20 for passing through the medical instrument over at least substantially the length of the elongate section 18.The elongate section 18 can generally be designed as a dilator unit. An elastically deformable cover element 22 is arranged along the elongate section 18 on an outer wall of the lumen 20. The cover element 22 can be deformed between a basic position, in which the cover element 22 rests against the outer wall of the lumen 20, and a guide wire position, in which the cover element is moved away from the outer wall of the lumen 20 by a guide wire 24 and forms a guide channel 26 for the guide wire 24. The elastically deformable cover element 22, which can be made of silicone, for example, is band-shaped in the present embodiment and runs along a central axis M of the elongate section 18, with lateral edges 28 of the cover element 22 being integrally connected to the outer wall of the first lumen 20.In other words, the cover element 22 forms an expandable layer or "skin" that extends from the insertion section 16 along the outer wall of the elongated section 18 and parallel to the central axis M. Without the guide wire 24, the cover element 22 preferably lies flush against the outer wall, so that it initially requires practically no additional space. The guide wire 24 deforms the cover element 22 radially outward, thereby exposing the guide channel 26 through which the guide wire 24 can be moved. The guide channel 26 is thus delimited radially outward by the cover element 22 and radially inward by the outer wall of the lumen 20. In general, it should be noted that the terms "axial" or "axial," "radial" or "radial" always refer to the central axis M of the elongated section 18, unless the context implicitly or explicitly indicates otherwise. As can be seen in Fig.2, the elongated section 18 consists of a composite tube 30 which delimits the lumen 20 which is circular in cross-section. The composite tube 30 has a kink-resistant, flexible base tube 32. In the simplest embodiment, the elongated section 18 can also consist exclusively of the base tube 32. Radially inwardly, on the base tube 32 there is an inner layer 34 which, in some embodiments, can have a lower coefficient of sliding friction than the base tube 32 in order to facilitate the insertion and removal of the medical instrument. The inner layer 34 can, for example, consist of a fluorinated, in particular perfluorinated hydrocarbon, for example PTFE (polytetrafluoroethylene), although other materials are also conceivable. In the example shown, an outer layer 36 is applied radially outwardly to the base tube 32, which forms the outer wall of the lumen 20 and against which the cover element 22 rests in the basic position.In some embodiments, the outer layer 36 can also have a lower coefficient of sliding friction, i.e., lower friction, than the base tube 32, in order to facilitate insertion and removal of the UAS 10 into and from a ureter 56. The outer layer 36 can, for example, be made of the same material as the inner layer 34 or of a different material. The base tube 32 can have the greatest wall thickness of the composite tube 30, while the inner and / or outer layers 34, 36, in contrast, can have smaller wall thicknesses or layer thicknesses. In principle, the composite tube 30 can consist of more or fewer interconnected layers or materials.

[0030] Fig. 3 shows a schematic perspective view of a proximal end region 14 of the ureteral access sheath 10 according to a further exemplary embodiment. In contrast to the previous exemplary embodiment, the elastically deformable cover element 22 is arranged, at least in the basic position, predominantly or completely in a groove 38 of the outer wall of the lumen 20, which preferably runs axially parallel to the central axis M. As a result, the cover element 22 initially, i.e. without the guide wire 24 or in the basic position, does not require any additional space, so that the UAS 10 can be inserted and removed accordingly easily. It can be provided that the cover element 22 does not protrude, or at least not significantly, beyond a circumference of the elongated section 18, even with the guide wire 24 or in the guide wire position.

[0031] Also visible is the insertion section 16 arranged at the distal end 12, which in this case comprises an insertion funnel 40 for the medical instrument and a port 42 for the guide wire 24 arranged distally in front of the insertion funnel 40. The port 42 is preferably arranged at an acute angle to the central axis M of the elongated section 18. A guide wire 24 can thus be inserted or reinserted at any time via the expandable cover element 22, which runs parallel to the lumen 20 but is spatially separated from it, even if the main lumen 20 is blocked in any way. In the event that the main lumen 20 of the UAS 10 is blocked and the entire UAS 10 must be removed, the present invention offers the possibility of leaving the guide wire 24 in the urinary tract.After removing the UAS 10 and removing the blockage in the lumen 20, the entire UAS 10 can be reinserted in the conventional manner via this guidewire 24. Conversely, the present invention offers the advantage that the guidewire 24 only needs to be reinserted when necessary. In cases where the lumen 20 is not blocked, reinsertion of the guidewire 24 is not necessary. This eliminates the need for the user to have a guidewire 24 in the kidney 44 (see Fig. 7), which can be disruptive during various operations such as laser stone fragmentation.

[0032] Fig. 4 shows a side view of the ureteral access sheath 10 according to a further embodiment with a closure device 46, by means of which the insertion section 16 and the elongated section 18 can be closed when the access sheath 10 is not in use. For this purpose, the closure device 46 has an elongated closure element 48, which is complementary to the lumen 20 and can completely fill it to prevent the entry of contaminants. Furthermore, the closure device 46 comprises a cover element 50 connected to the closure element 48, which can be brought into engagement with corresponding locking elements 52 of the insertion section 16. The closure device 46 can thus be detachably connected to the UAS 10 via a type of clip connection. In Fig. 4 one can see the guide wire 24, which is guided proximally out of the port 42 and distally out of the guide channel 26 formed by the cover element 22.

[0033] Fig. 5 shows a perspective view of the distal end region 12 of the ureteral access sheath 10 according to Fig. 4, wherein the guide wire 24 is moved according to arrow V in the direction of the distal end region 12. In contrast to the first exemplary embodiment, the cover element 22 in the present exemplary embodiment is hose- or tube-shaped and completely surrounds the outer circumference of the lumen 20. Due to its elastic properties, it also lies closely against the outer wall of the lumen 20 in this case without a guide wire 24. It can be seen that the guide wire 24 has already been pushed largely in the direction of the distal end region 12, but has not yet been moved out of the guide channel 26 formed by the cover element 22. The cover element 22 is thus partially in the guide wire position and partially in the basic position.

[0034] Fig. 6 shows a perspective view of the distal end region 12 of the ureteral access sheath 10 according to Fig. 5, with a distal end of the guide wire 24 pushed out of the guide channel 26 formed by the cover element 22. The cover element 22 is thus fully in the guide wire position. As can also be seen, the elongated section 18 has an atraumatic tip 54 distally.

[0035] Fig. 7 shows a schematic representation of a kidney 44, in whose ureter 56 a ureteral access sheath 10 according to the invention and a guide wire 24 are arranged. The ureteral access sheath 10 was inserted along the guide wire 24 according to arrow VII in the manner described above, with the guide wire 24 being guided in the guide channel 26 formed by the cover element 22. LIST OF REFERENCE SYMBOLS:

[0036] 10 Ureteral access sheath

[0037] 12 distal end

[0038] 14 proximal end

[0039] 16 Introductory section

[0040] 18 elongated section

[0041] 20 lumens

[0042] 22 Cover element

[0043] 24 Guidewire

[0044] 26 guide channel

[0045] 28 edges

[0046] 30 composite pipe

[0047] 32 base tube

[0048] 34 inner layer

[0049] 36 Outer layer

[0050] 38 grooves

[0051] 40 insertion funnels

[0052] 42 ports

[0053] 44 Kidney

[0054] 46 locking device

[0055] 48 locking element

[0056] 50 cover element

[0057] 52 locking elements

[0058] 54 lace

[0059] 56 ureters

[0060] M central axis

[0061] V, VII Arrow

Claims

CLAIMS: 1 . Ureteral access sheath (10) for insertion into a ureter (56) of a human or animal patient, wherein the access sheath (10) has, at a proximal end, an insertion section (16) for a medical instrument and an elongated section (18) extending from the proximal insertion section (16) to a distal end (12) of the access sheath (10), wherein the elongated section (18) comprises at least one lumen (20) for passing through the medical instrument over at least substantially the length of the elongated section (18), characterized in that an elastically deformable cover element (22) is arranged on an outer wall of the lumen (20) at least in regions along the elongated section (18), wherein the cover element (22) can be moved between a basic position, in which the cover element (22) rests against the outer wall of the lumen (20), and a guide wire position,in which the cover element (22) is moved away from the outer wall of the lumen (20) by a guide wire (24) and forms a guide channel (26) for the guide wire (24), is deformable., 2. Ureteral access sheath (10) according to claim 1, characterized in that the elastically deformable cover element (22) is at least partially tubular and surrounds the lumen (20) on the outside.

3. Ureteral access lock (10) according to claim 1 or 2, characterized in that the elastically deformable cover element (22) is at least partially band-shaped, wherein lateral edges (28) of the cover element (22) are preferably integrally connected to the outer wall of the first lumen (20).

4. Ureteral access sheath (10) according to claim 3, characterized in that the elastically deformable cover element (22) is arranged at least predominantly in a groove (38) of the outer wall of the lumen (20), at least in the basic position.

5. Ureteral access sheath (10) according to one of claims 1 to 4, characterized in that the insertion section (16) comprises an insertion funnel (40) for the medical instrument and / or a port (42) for the guide wire (24), wherein the port (42) is preferably arranged at an acute angle (54) to a central axis (M) of the elongate section (18).

6. Ureteral access sheath (10) according to one of claims 1 to 5, characterized in that the elongated section (18) comprises a composite tube (30) which delimits the lumen (20).

7. Ureteral access sheath (10) according to claim 6, characterized in that the composite tube (30) comprises a kink-resistant and / or flexible base tube (32) and / or that the composite tube (30) comprises a radial inner layer (34) with a lower coefficient of sliding friction than an adjacent layer and / or that the composite tube (30) comprises a radial outer layer (36) against which the cover element (22) rests in the basic position.

8. Ureteral access sheath (10) according to one of claims 1 to 7, characterized in that the elongated portion (18) has an atraumatic tip (54) distally.

9. Ureteral access sheath (10) according to one of claims 1 to 8, characterized in that a closure device (46) is provided, by means of which the insertion section (16) and the lumen (20) can be closed when the Access gates can be locked.

10. Ureteral access sheath (10) according to one of claims 1 to 9, characterized in that a guide wire (24) runs through the guide channel (26) and / or that a ureterorenoscope is guided through the insertion section (16) and the elongated section.

Images