Tympanostomy tube

Abstract

To provide a tympanostomy tube having improved bending characteristics and strength characteristics in both introduction and use.SOLUTION: A fluidic bridging tube 1, for bridging membranes in the human or animal body allowing the passage of fluid, has a proximal flange 2, an inter lumen connector 3 with a lumen, and a distal flange 4. The tube comprises a metal skeleton or scaffold structure 51 and a surrounding polymer which is softer than the scaffold structure. The scaffold structure 51 has a tubular mesh providing structural strength to the inter lumen connector. The tubular mesh has members defining substantial rectangular mesh apertures, and distal crowns. At its proximal end the scaffold structure comprises spines extending from a proximal tubular mesh rim. The spines provide structural strength to the proximal flange 2. In the preferred embodiment, the tube is a tympanostomy tube.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to tympanostomy tubes and other tubes for passing fluids through the body across a wall or membrane having properties broadly similar to the tympanic membrane. An example is a tube for bridging a membrane within the body, such as an ocular drainage device. [Background technology]

[0002] WO2019 / 086608 (AventaMed Designated Activity Company) describes a tympanostomy tube and placement device. The tube has a proximal flange that acts as a stop or depth perception during placement, a lumen interconnect for fluid passage across the tympanic membrane, and a distal flange that collapses during introduction and unfolds when positioned distal to the membrane. In this case, and in many other placement techniques, it is desirable for the distal flange to be more flexible than the proximal flange to provide effective introduction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 086608 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention is directed to obtaining tympanostomy tubes with improved flex and strength characteristics during both insertion and use. [Means for solving the problem]

[0005] The inventors describe a fluid bridge tube as set out in the accompanying claims 1 to 17, and a manufacturing method as set out in claim 18.

[0006] The inventors also describe a fluid bridge tube for use in humans or animals, the tube comprising a proximal flange, a lumen interconnect with a lumen, and a distal flange, the tube comprising a scaffold structure and an outer material that is softer than the scaffold structure and completely or partially surrounds the scaffold structure.

[0007] Preferably, the tube is a tympanostomy tube.

[0008] Preferably, the scaffold structure comprises a tubular mesh extending through at least some of the luminal interconnects. Preferably, the tubular mesh has members defining substantially curved rectangular mesh openings, the openings optionally having substantially equal sides. Preferably, the tubular mesh comprises a crown at a distal end thereof.

[0009] Preferably, the tubular mesh includes a solid rim at its proximal end.

[0010] Preferably, the scaffolding structure comprises projections which extend with the radial components to provide structural support to at least the proximal flange. Preferably, the scaffolding structure comprises substantially equally radially spaced projections.

[0011] Preferably, the scaffold structure comprises a material selected from stainless steel, nitinol, titanium, or a polymer.

[0012] Preferably, the outer material comprises a medical grade silicone rubber.

[0013] Preferably, the outer material is overmolded onto the scaffold structure.

[0014] Preferably, the scaffold structure is completely surrounded (encased) by the outer material.

[0015] Preferably, the distal flange does not include any part of the scaffold structure.

[0016] The inventors have also described a method of manufacturing a fluid bridge tube of any of the examples described herein, the method including providing a scaffold structure and overmolding an outer material to form the shape of a proximal flange, a lumen interconnect with a lumen, and a distal flange.

[0017] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view of a tympanostomy tube. [Diagram 2] This is a diagram showing the internal structure with hidden lines. [Diagram 3] FIG. 1 is a perspective view of a tube scaffold or framework structure. [Figure 4] FIG. 13 is a cutaway view showing both the scaffold structure and the overmold. [Diagram 5] FIG. 13 is a cutaway view showing both the scaffold structure and the overmold. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Referring to FIG. 1, a tympanostomy tube 1 includes: - a proximal flange 2; - a lumen interconnection 3 forming a lumen 5; - a distal flange 4.

[0020] The proximal flange 2 has four equally spaced through holes for retention fingers of a deployment device that align with tabs 20 on the distal flange 4. In other examples, the number and / or spacing of the through holes and associated tabs on the distal flange may vary. The holes 10 have a curved outer surface and a circumferentially curved inner surface 12. Each tab 20 has a radial portion 21 and an axial portion 22, the latter at an acute angle of about 10° with respect to the longitudinal axis of the tube 1. The longitudinal axis is the central axis of the lumen 5.

[0021] The tube 1 is introduced in the manner described in WO2019 / 086608, which is achieved by a deployment device having longitudinal fingers that extend through holes 10 and press radially inwards on the distal flange 4, more specifically tab 20, radial portion 21, and axial portion 22. As the deployment device needle penetrates the tympanic membrane, the proximal flange, with its distally facing surface in contact or nearly in contact with the tympanic membrane, acts as a stop or depth perception device for the device from the tympanic membrane. The deployment device retention fingers and needle are then retracted, causing tab 20 of distal flange 4 to pop out into the radial position shown in FIG. 1, thereby fixing tube 1 in place across the membrane.

[0022] As shown in FIG. 2, the construction of the tube 1 comprises an inner framework or scaffolding structure 51 of metal (or other suitable rigid material such as a rigid polymer) and a surrounding outer material 50 which is softer.

[0023] In this case, the material of the scaffold structure 51 is stainless steel and the surrounding outer material 50 is a silicone overmold. In other examples, the framework may comprise titanium or other suitable material that is also stiffer than the outer material.

[0024] The outer material 50 is preferably overmolded and preferably comprises a polymer of a more resilient, less stiff material than the scaffold. The overmolding material in this example is medical grade liquid silicone rubber, preferably having a Shore A hardness in the range of 50-90.

[0025] 3, scaffold structure 51 comprises a tubular mesh 60 with integral structural members 61 defining curved rectangular openings 62. The proximal end of tubular mesh 60 is of greater strength forming a solid rim 63. The distal end of tubular mesh 60 comprises a distally directed crown 64 formed by distal member 64.

[0026] At the proximal end, there are four metal projections 68 that extend radially from the rim 63, spaced radially at equal 90° intervals. The projections 68 are integral with the tubular mesh 60.

[0027] The tube is manufactured by fabricating the structure 51 using known techniques for fabricating stents. One example is to laser cut the pattern, fold and weld. Another example is to laser cut from a tube with the correct inside diameter (ID) and wall thickness, then form the legs after the part is manufactured. Silicone 50 is then overmolded by injection molding. The internal scaffolding is placed and held in place in the mold, and silicone is injection molded onto the scaffolding. The overmolding 50 is shown in more detail in Figures 4 and 5.

[0028] The manufactured tube 1 has excellent strength and flex characteristics, with the proximal flange 2 having greater stiffness than the distal flange 4 due to the metal protrusions 68. The lumen interconnect 3 has excellent strength to remain open during introduction and for its life after insertion, which in one example may be up to about two years, but in other examples may be permanent. The distal crown 64 allows for a configuration in the distal direction that facilitates insertion through the tympanic membrane with minimal resistance.

[0029] The tube 1 has a rigid structure with the exception of the distal flange 4 with its upstanding portion 20, which desirably allows for effective attachment to a tube delivery system and provides a collapsed, narrow lead-in portion of the distal flange. The rigid lumen and proximal flange allow for the tube to be introduced without collapsing or deforming the tube. The scaffolding structure ensures that the lumen will remain intact in vivo throughout the life of the device, whereas an all-silicone tube may kink or collapse due to external forces acting on it.

[0030] (Clinical Benefit) The silicone material is in contact with the body, but the tube has the rigidity of a harder material underneath, such as fluoroplastic, or titanium, or metal.

[0031] The scaffold structure ensures that the lumen will not collapse in vivo, thus reducing the risk of the tube becoming blocked during use.

[0032] The scaffold structure provides stiffness to the proximal flange. It is known that the diameter of the distal flange of a tympanostomy tube affects the rate of extrusion of the tube, but it is also known that the proximal flange affects the rate of extrusion as the natural growth of the tympanic membrane pushes against the proximal flange, which extrudes the tube from the tympanic membrane over time. If a more flexible outer (proximal) flange were present, unlike the tubes described herein, the flexible proximal flange would deform rather than be pushed away from the tympanic membrane, which may impair the body's ability to extrude the tube in a timely manner.

[0033] A more flexible distal flange and interflange distance allows for easier tube placement even in cases of a recessed tympanic membrane, as the distal (inner) flange deforms open and engages the inside of the tympanic membrane and is precisely introduced into the incision.

[0034] The mechanical properties of the tube with the silicone and stainless steel inner allow flexibility to manufacture the tube in other tube configurations, such as a T-tube, which may be included in the device as an alternative tube option for the clinician. Typically, T-tubes have a very large distal (inner) flange (e.g., about 10 mm) and remain in the body for 2 years or more, and possibly indefinitely.

[0035] Color is easily added to the silicone material, for example a blue color would allow the clinician to easily see the outer flange of the tube during surgical placement, allowing for more accurate placement. Post-operatively, the clinician can more easily see the tube in situ, which can often be difficult when examining a pediatric ear, especially in small ears or moving patients.

[0036] If the tube does not expel naturally, it must be surgically removed. The silicone inner flange is flexible, making it easier and less traumatic to remove the tube when necessary. This may result in a smaller perforation rate.

[0037] The invention is not limited to the described embodiments, which may differ in configuration and details. It is envisioned that the tubular mesh structural member may have a smaller or larger cross-sectional area depending on clinical requirements. In some cases, protrusions may be present on the distal flange, in which case they may be softer than the protrusions on the proximal flange, for example by having a smaller cross-sectional area. Any desired number of protrusions may be present on the proximal flange, and on the distal flange, if present. The amount of outer material is selected to ensure that the scaffold does not protrude in use, and of course according to other clinical requirements.

[0038] As mentioned above, the tube may be for other in vivo medical applications, such as for the transfer of fluid between two biological structures separated by a thin membrane, but is particularly preferred for use in the tympanic membrane.

[0039] The tubes may be referred to as fluid bridge tubes for the transfer of any fluid, gas, or liquid, including air for ventilation. The scaffold structure may also be configured to deploy during introduction, either by self-expansion using a shape-memory scaffold material such as Nitinol, or by applied pressure from the inside, for example using a balloon.

[0040] It is also envisioned that the outer material may not be overmolded, but instead the scaffold structure may be embedded, for example by pressing the scaffold structure into a tube- or sleeve-shaped body of the outer material. It is also envisioned that the outer material does not completely surround the scaffold structure.

[0041] It is envisioned that the tubes and scaffolds may be manufactured in a collapsed state. In one embodiment, the scaffold material may be fabricated from stainless steel or titanium material, which will utilize an internal deployment mechanism, such as an inflatable balloon, during introduction of the tube. In another embodiment, the scaffold material may be fabricated from a metal with shape memory properties, which will deploy upon release from the hold-down component of the device. In either of these embodiments, the silicone overmold will expand to a new, larger size as the scaffold deploys. These embodiments allow for a smaller device, which will improve the ability to puncture the tympanic membrane and visualization of the device during introduction. In another example, the soft silicone material may be a soft material suitable for medical use, such as a thermoplastic elastomer "TPE."

Claims

1. A fluid bridge tube (1) for human or animal use comprising a proximal flange (2), a lumen interconnect (3) with a lumen (5), and a distal flange (4), The fluid bridge tube (1) at least partially comprises a scaffold structure (51) and an outer material (50) that is softer than the scaffold structure (51) and completely or partially surrounds the scaffold structure (51).

2. The fluid bridge tube (1) according to claim 1, wherein the fluid bridge tube (1) is a tympanostomy tube.

3. 3. The fluid bridge tube (1) of claim 1 or 2, wherein the scaffold structure (51) comprises a tubular mesh extending through at least some of the lumen interconnects (3).

4. The fluid bridge tube (1) of claim 3, wherein the tubular mesh comprises members (61) defining substantially curved rectangular mesh openings.

5. The fluid bridge tube (1) of claim 4, wherein the mesh openings have substantially equal sides.

6. A fluid bridge tube (1) according to any one of claims 3 to 5, wherein the tubular mesh is provided with a crown (64) at its distal end.

7. 7. The fluid bridge tube (1) of any one of claims 3 to 6, wherein the tubular mesh is provided with a non-opening rim (63) at its proximal end.

8. 8. The fluid bridge tube (1) of any one of claims 1 to 7, wherein the scaffolding structure (51) comprises a plurality of protrusions (68) extending with radial components to provide structural support to at least the proximal flange (2).

9. The fluid bridge tube (1) of claim 8, wherein the plurality of projections (68) are substantially equally spaced radially.

10. The fluid bridge tube (1) of any one of claims 1 to 9, wherein the scaffold structure (51) comprises a material selected from stainless steel, nitinol, titanium, or a polymer.

11. The fluid bridge tube (1) according to any one of the preceding claims, wherein the outer material (50) comprises a medical grade soft material, preferably silicone rubber.

12. The fluid bridge tube (1) of any one of claims 1 to 11, wherein the outer material (50) is overmolded onto the scaffold structure (51).

13. The fluid bridge tube (1) of any one of claims 1 to 12, wherein the scaffold structure (51) is completely surrounded by the outer material (50).

14. The fluid bridge tube (1) of any one of claims 1 to 13, wherein the distal flange (4) does not include any part of the scaffold structure (51).

15. The fluid bridge tube (1) of any one of claims 1 to 14, wherein the scaffold structure (51) is radially expandable from the inside.

16. 16. The fluid bridge tube (1) of claim 15, wherein the scaffold structure (51) is radially expandable from the inside by a balloon, and the outer material (50) is configured to expand together with the deployment of the scaffold structure (51).

17. 17. The fluid bridge tube (1) of any one of claims 1 to 16, wherein the scaffold structure (51) comprises a shape memory material configured to deploy from a hold-down component, and the outer material (50) is configured to deploy together with the deployment of the scaffold structure (51).

18. A method for manufacturing a fluid bridge tube (1) according to any one of claims 1 to 17, comprising the steps of: Providing said scaffold structure (51); and overmolding the outer material (50) to form the shape of the proximal flange (2), the lumen interconnect (3) with the lumen (5), and the distal flange (4).

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