Patent Application
20250135169
The invention relates to a patient-specific implant for insertion into a body cavity of a patient, for example into the round window niche of the middle ear, or in another body cavity like:
The invention also relates to a method of manufacturing such an implant.
There are already proposals for the manufacture of patient-specific implants. However, the suitability of such known implants for insertion into a patient's body cavity is severely limited, especially if the body cavity is accessible only through a narrowed body opening, such as the round window niche.
It is an object of the invention to provide an improved implant which can be inserted simply and reliably even in body cavities which are accessible only via a narrowed body opening. Furthermore, an advantageous method for manufacturing such an implant is to be disclosed.
This object is achieved by a patient-specific implant for insertion into a body cavity of a patient, the implant having an implant body and a handle attached directly or indirectly to the implant body, wherein the handle is adapted for holding and guiding the implant during insertion into the body cavity, the implant body having an outer contour which corresponds predominantly to the inner contour of the body cavity of the patient, characterized in that at least the implant body contains a medical active substance which is deliverable from the implant body to the patient. Such an implant can be placed reliably and safely in the body cavity. The implant can be held by the handle and guided by the user or a robot during the insertion process. At the implantation site, the implant body can then deliver the medical agent to the patient.
Advantageously, the implant is designed for permanently remaining in the body cavity, at least for a duration required for the delivery of the medical agent to the patient. In other words, the implant is designed for permanently remaining in the body cavity for this duration with the handle, which means the handle is not detached from the implant body after insertion of the implant in the body cavity. For example, the handle may be permanently connected to the implant body such that the handle is not detachable from the implant body. Of course, the handle should be small enough that it can remain in the body cavity without causing problems for the patient. In particular, the maximum dimension of the handle can be smaller than the maximum dimension of the implant body. For the insertion of the implant for insertion into the body cavity a tool, e.g. tweezers or a forceps, can be used which is removed after the insertion process. In particular, the handle can have a size which does not allow insertion of the implant in the body cavity without an additional tool which is not part of the implant.
The patient-specific implant can be patient-specific in one or more of the following ways:
According to an advantageous embodiment of the invention, the implant body is formed as a solid body having substantially no air pockets. This has the advantage that the implant body can be provided both mechanically stable and to a certain extent compressible for the insertion process.
According to an advantageous embodiment of the invention, the implant body can have a higher compressibility than the handle. This has the advantage that the implant can be reliably held and guided via the more rigid handle compared to the implant body, while the implant body can also be guided through constricted areas to the body cavity due to its higher compressibility. For example, the implant body may be provided from a material having a higher compression modulus than the material of the handle. It is also possible that the implant body and the handle both have the same material and same compressibility.
According to an advantageous embodiment of the invention, the implant body is elastically compressible by at least 20%. In this way, the implant body can have sufficient softness when inserted into the body cavity. For example, the implant body can be compressed to at least 20% less volume than in the uncompressed state without permanent damage.
However, the implant body does not necessarily need to be compressible, to change in volume, but in shape. For example, the implant body can be sqeezed to be put through narrow passages. For this purpose, the implant body can have an elasticity and/or flexibilty such it can be sqeezed during the insertion process. According to an advantageous embodiment of the invention, the implant body can have a greater elasticity than the handle. This allows the implant body to conform well to the body cavity and, during the insertion process, to the possibly narrower body caves upstream of the body cavity. For example, the implant body may be made of a material with a greater modulus of elasticity than the material of the handle. It is also possible that the implant body and the handle both have the same material and same elasticity.
According to an advantageous embodiment of the invention, the implant can have a marking by which the position and/or orientation of the implant during the implanting process in the body cavity is recognizable to the user. This has the advantage that the position and/or orientation of the implant can be checked by the user at any time during the implantation process and the correct implantation direction can be ensured. Such a marking thus serves as an orientation aid for the user when implanting the implant into the body cavity. The marking may, be in the form of an asymmetric shape of the handle itself, for example the handle may be shaped like an arrow. It is advantageous if the marking is arranged on the handle, because it is then clearly visible to the user during the entire implantation process.
According to an advantageous embodiment of the invention, the implant body is biodegradable. Accordingly, the implant body may slowly decompose in the body cavity, which has the advantage that no additional intervention is required for explantation of the implant body. The entire implant may also be biodegradable.
According to an advantageous embodiment of the invention, the implant body can have a multilayer structure of active substance-loaded material with active substance concentrations and/or active substances differing in the layers. In this way, a time-programmed active substance release can be realized optionally with respect to the active ingredient concentration and/or with respect to the type of active ingredient.
According to an advantageous embodiment of the invention, active substance-producing cells are integrated in the implant body, by means of which the medical active substance that can be delivered to the patient can be produced. In this way, a constant delivery of the active substance to the patient can be ensured over a longer period of time.
According to an advantageous embodiment of the invention, at least the implant body is manufactured by means of an additive manufacturing process. This allows a particularly precise patient-specific provision of the implant body or the implant. The entire implant may also be manufactured using an additive manufacturing process. The additive manufacturing process can be, for example, a 3D printing process, e.g. laser printing, extrusion printing, inkjet printing.
The object of the invention is further achieved by a method for manufacturing a patient-specific implant of the type explained above, comprising the following steps:
The object of the invention is further achieved by a method for manufacturing a patient-specific implant of the type explained above, comprising the following steps:
The computer programs closes the potential gap between the handle and the filled shape of the body cavity.
The previously explained advantages can also be realized by this method. The patient data can be obtained, for example, by means of an examination process of the patient performed before the execution of the method, e.g. by a radiological three-dimensional examination, in particular by an examination by means of computer tomography, magnetic resonance tomography, time-of-flight laser scanning, 3D microscopy, 3D reconstruction based on image processing techniques, OCT imaging, and/or digital volume tomography.
The invention is explained in more detail below with reference to exemplary embodiments using drawings.
The invention describes a new class of implants that can be inserted as a solid body into the round window niche (RWN), cochlea, vestibular system, cranium, cavum tympani, mastoid or sinus frontalis and can locally deliver active substances for the treatment of various diseases. For atraumatic placement, secure retention and effective drug delivery, it is advantageous to customize the implants to the geometry of the individual target region. In order to be able to be inserted into the cavity, it is advantageous if the implant is compressible and/or flexible and has a marking for the correct implantation direction.
The implant according to the invention may thus having one, more or all of the following features:
To avoid explantation of the implants, they can be made of biodegradable materials. Targeted drug release into e.g. the inner ear may also be implemented. Additionally, the implant according to the invention may have one, more or all of the following features:
Round window niche implants allow the treatment of the inner ear with active substances that diffuse from the implant through the round window membrane into the inner ear. Thus, pathologies such as Menier's disease, hearing loss and cochlear implant-associated trauma reactions can be treated. To date, it is not possible to diffuse drugs into the inner ear in a controlled manner, since the drug-releasing implant surface is not adapted to the round window membrane of the individual patient. There are considerable variations in size and shape, as well as a pseudomembrane if necessary. The implant of the invention is the first drug-releasing system that is adapted to the individual anatomy of the patient and can therefore be safely implanted in the round window niche to deliver its active ingredients to the inner ear in an effective and controlled manner. Its compressibility allows atraumatic insertion through the isthmus into the round window niche, where it remains, as the expansion after insertion prevents it from slipping out.
The handle may have an arrow shape and thus also serves to orient the surgeon in which direction the implant is to be placed. The shape and thickness of the handle can be varied so that an optimal support structure for the individualized implant body can be printed.
In a manufacturing step, the handle for the implant is created on the surface of the implant facing the middle ear (step 12 in
In general, biopolymers, synthetic polymers, polymer blends, nanocomposites, functional polymers and cell-loaded systems can be used as materials for the implant body and/or the handle. The materials to be printed should be dimensionally stable on the one hand, but on the other hand compressible in order to be introduced into the cavity. Hydrogels are suitable for this purpose, as they have a lattice structure in the linked state, which enables the inclusion of active substances with subsequent diffusion out of the material. At the same time, the material should be degradable in order to avoid explantation of the implant after successful therapy.
The materials are either mixed with medical active substances prior to manufacture or the implant is filled with medical active substances by diffusion after manufacture.
The amount of medical active substances to be introduced depends on the pathology addressed and varies accordingly.
Some possible medical active substances are listed in Table 1 below:
The implant can be manufactured, for example, by means of additive manufacturing processes listed below.
The implants should be as biodegradable as possible=bioresorbable=bioabsorbable. They should either dissolve independently in the body or be induced to dissolve.
Reduced dissolution of alginate can be done by injection of alginate lyase into the middle ear. Chitosan can be dissolved by injection of a low pH solution. It must be noted that the solutions must be biocompatible.
Immortalized, drug-producing cells can be introduced into the implant. The factors to be produced include, but are not limited to, growth factors and other proteins, as well as antioxidant molecules, which can be neuroprotective as well as antioxidant and thus protect specific inner ear structures from degeneration. The cells should survive in the implant for at least 4 weeks. The drugs must diffuse from the implant into the inner ear, but the cells must be firmly entrapped in the material to avoid an immune response from the patient. Cells of any origin such as stem cells, fibroblasts or human umbilical vein endothelial cells (HUVEC) can be introduced.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21209553.3 | Nov 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/082441 | 11/18/2022 | WO |
