Teaching method for the reconstruction of an aortic valve leaflet

Abstract

A jig (10) for the reconstruction of a leaflet of an aortic valve, characterized in that the jig (10) is made of a material that can be plastically deformed under manual force.

Description

[0001] The invention relates to a teaching for the reconstruction of a leaflet of an aortic valve.

[0002] The aortic valve (valva aortae) is a valve system located in the aortic orifice of the left ventricle. It opens during systole under the ventricular pressure of the blood and closes during diastole under arterial pressure. The aortic valve typically has three leaflets, which attach to the annulus fibrosus, separated by commissures. In the closed position, the leaflets seal against each other with their free margins to prevent backflow of blood from the aorta into the left ventricle. In the open position, the free margins of the elastic, flexible leaflets move away from each other.

[0003] Aortic valve defects can be treated using various surgical procedures. The defective aortic valve can be completely or partially replaced with a mechanical or biological valve prosthesis. Replacing individual leaflets of an aortic valve is a particularly well-known technique.

[0004] To determine the size of an aortic valve leaflet implant, special standardized gauges are known to be used as aids for size definition, in order to support the surgeon in the reconstruction and to reduce the operating time.

[0005] Known are rigid plastic templates, roughly shaped like a flattened aortic valve leaflet, which are available in various sizes to guide the surgeon during surgery in determining the size and shape of the implant material required for aortic valve leaflet reconstruction. A set of several such templates of different sizes is known, with the diameter of the annulus for which each template size is suitable marked on the template. During the operation, the diameter of the patient's annulus is measured, and the appropriate template is then selected. The template can then be used like a stencil to transfer the shape and size to the implant material, thus providing a basis for the reconstruction.However, the teachings do not usually specify the exact shape and size of the valve leaflet, as the actually required shape and size are determined intraoperatively by the surgeons based on the existing anatomical encounters.

[0006] From US patent 2009 / 0192602 A1, a device for determining the annulus of a heart valve using minimally invasive methods is known, which has a plate for size determination that is deformable in order to be passed through constrictions of the minimally invasive insertion route.

[0007] US Patent 2009 / 0192600 A1 also discloses a device for determining the size of the annulus of a heart valve, in which size determination plates are provided at two opposite ends, which have different shapes but belong to the same size of an annulus.

[0008] The object of the invention is to provide a method for the reconstruction of an aortic valve leaflet, with the aid of which the size and shape of the aortic valve leaflet implant can be better estimated. In particular, faster estimation should be made possible in order to reduce the operating time.

[0009] The problem is solved according to the invention by a teaching for the reconstruction of a leaflet of an aortic valve with the features of claim 1.

[0010] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0011] The inventive device for reconstructing an aortic valve leaflet is made of a material that is plastically deformable under manual force. This allows the surgeon to deform the device by hand with minimal effort during the operation, thus replicating and better visualizing the three-dimensional shape of the leaflet to be replaced. While known rigid devices do show the contours of the leaflet to be replaced, they depict it as a leaflet spread out in a plane, whereas the leaflet has a convex shape when sewn into the aortic valve. Because the device is made of a plastically deformable material, the surgeon can also replicate the three-dimensional shape of the leaflet to be replaced, so that the required size can generally be determined more quickly and accurately.Furthermore, the plastic deformation of the gauge allows the gauge to be easily bent smooth again after determining the optimal size and thus laid flat on the implant material in order to mark the size of the desired implant on the implant material using the gauge and to cut the implant material to the desired size.

[0012] The device is preferably made from a biocompatible material for the safety and protection of the patient.

[0013] Preferably, the guide is made of a sterilizable material so that it can be cleaned and reused after an operation.

[0014] Advantageously, the jig is made of a material with a flexibility of more than 10 degrees. This means, in particular, that the material can be bent at an angle of 10 degrees or more without splintering or breaking. For example, the jig can be made of flexible steel, flexible aluminum, or flexible plastic, allowing for manual deformation of the material without the use of machinery.

[0015] Particularly preferred is the teaching made from a nickel-titanium alloy, which is an example of a material that is both plastically deformable and biocompatible and sterilizable.

[0016] According to a particularly preferred embodiment of the invention, the teaching piece is made of a memory alloy. A memory alloy has the advantage that it is plastically deformable at a certain temperature, for example, room temperature, but returns to its original shape when a higher upper transition temperature is exceeded. If the teaching piece is made of such a material, it can be bent into the desired shape during the operation, but is returned to its original shape during subsequent cleaning and sterilization, which is generally carried out at a temperature above the higher upper transition temperature.

[0017] The teaching advantageously has a thickness in the range of 0.05 mm to 2 mm, advantageously a thickness in the range of 0.25 mm to 0.45 mm, preferably a thickness in the range of 0.3 mm to 0.36 mm, for example a thickness of 0.33 mm, in order to be able to replicate the thickness of the aortic valve leaflet as accurately as possible.

[0018] Advantageously, the teaching has a width in the range of 15 mm to 40 mm in order to replicate the widths of aortic valve leaflets that are commonly found.

[0019] A particularly preferred embodiment of the invention provides that the device has at least one, preferably several, and in particular three, recesses on its outer circumference. These recesses can serve as markings, for example, for determining the commissure and the center of the implant. Such markings make it easier for the surgeon to correctly align the implant to be inserted at the commissure.

[0020] Preferably, the teaching has traumatically rounded edges to avoid injury to the implant material or the patient.

[0021] According to the invention, a set of several gauges according to the invention in different sizes is provided to give the surgeon gauges of different sizes during the operation, by means of which he can determine the optimally fitting size of an aortic valve leaflet implant to be inserted.

[0022] The invention is explained in detail with reference to an embodiment illustrated in the following figures. These show: Fig. 1 a top view of an embodiment of a teaching according to the invention for the reconstruction of a leaflet of an aortic valve and Fig. 2 a side view of the teaching according to Fig. 1.

[0023] An embodiment of a teaching 10 according to the invention for the reconstruction of a leaflet of an aortic valve is described in the Fig. 1 and Fig. Figure 2 shows the gauge 10, which approximately has the outer contour of a leaflet of an aortic valve in its spread-out state in a plane. The contour of the gauge 10 can have two straight lines arranged at an obtuse angle, the free ends of which are connected by a curved line, for example, at least partially, of a circle.

[0024] According to the invention, the device 10 is made from a plastically deformable material. A plastically deformable material is defined as a material that deforms irreversibly under the influence of force and retains this shape even after the force has been applied. The material can be further deformed by applying force again and can also be returned to its original state. Manual force should be sufficient for deformation, so that plastic deformation is possible without mechanical intervention.

[0025] The gauge 10 can be made of a biocompatible material. Furthermore, the gauge 10 can be made of a sterilizable material. For example, the gauge is made of a material with a flexibility of more than 10 degrees. This means, in particular, that the material can be bent at an angle of 10 degrees or more without splintering or breaking. For example, the gauge can be made of flexible steel, flexible aluminum, or flexible plastic, with the chosen material being manually deformable.

[0026] According to one embodiment, the guide 10 can be made of a memory alloy, such that it is plastically deformable at room temperature and returns to its original shape when an upper transition temperature, which is higher than room temperature, is exceeded. During the operation, the surgeon can thus bend the guide 10 into the desired shape. The guide 10 retains this shape until it is either bent further by the surgeon or straightened, the latter, for example, to transfer the shape of the guide 10 onto the implant material by tracing it. If the guide 10 is cleaned in a washing machine or autoclave during instrument reprocessing and the upper transition temperature is exceeded, the guide 10 returns to its original shape.

[0027] For example, the teaching piece is made of a nickel-titanium alloy.

[0028] The teaching 10 can have a thickness d of 0.05 mm to 2 mm, advantageously a thickness of 0.25 mm to 0.45 mm, preferably a thickness d in the range of 0.3 mm to 0.36 mm, for example a thickness d of 0.33 mm. The teaching 10 can have a width b in the range of 15 mm to 40 mm.

[0029] One embodiment of the teaching 10 has at least one, preferably several, in the present embodiment three, recesses 15 on its outer circumference, particularly in the curved part of the outer circumference. The recesses 15 form markings. In particular, the three markings 15 can be arranged according to the Fig.In the embodiment of the teaching 10 shown in Figure 1, the markings are arranged such that one of them marks the axis of symmetry of the implant 10 and thus the center of the implant, while two markings 15 arranged symmetrically to each other on the side surfaces of the teaching 10 can mark the commissure. Such markings 15 make it easier for the surgeon to correctly align the implant, subsequently cut out with the aid of the teaching 10, at the commissure. In particular, the three markings 15 can indicate the two highest and the lowest point of the commissure.

[0030] The edges of the guide 10 can be designed to be atraumatically rounded in order to avoid damage to the implant material and injury to the patient.

[0031] According to the invention, a set of several teachers in different sizes is provided.

[0032] The teaching 10 according to the invention can be used as follows.

[0033] If a defective aortic valve leaflet needs to be replaced during surgery, the implant material, such as autologous pericardium, must be cut to the desired shape and size and then inserted in place of the removed defective aortic valve leaflet and sutured in place. To provide the surgeon with a tool for determining the appropriate size and shape of the aortic valve leaflet implant, guides for aortic valve leaflet reconstruction have been developed. The use of such guides significantly speeds up the fitting process and avoids lengthy adjustment times.

[0034] If the defective aortic valve leaflet was removed during the operation, the surgeon can select a gauge 10 from a set of gauges 10 according to the invention, initially choosing one that is the closest possible fit by eye, adapting it to the anatomical conditions by appropriate manual deformation, and holding it against the annulus of the aortic valve to determine whether the size of the selected gauge 10 is optimally suited. If necessary, the process can be repeated with a larger or smaller gauge 10.

[0035] Once the optimally fitting size of the gauge 10 has been determined, the selected gauge 10 can be bent back into a smooth shape, and its form can be transferred to the implant material, e.g., autologous pericardium, by tracing around the gauge 10 with a pen. The recesses 15 on the gauge 10 can mark the commissure and the center of the implant on the implant tissue, thus facilitating the surgeon's orientation when inserting the aortic valve leaflet implant, which is subsequently excised from the implant tissue.

[0036] Because the guide is made of a plastically deformable material, the surgeon can better replicate the actual anatomical shape of the aortic valve leaflet during the operation and more easily adapt the desired size to the anatomical conditions. If the optimal size of the guide can be selected more quickly and easily, the operating time is reduced, thus minimizing the invasiveness of the procedure and improving the patient's recovery. Furthermore, the plasticity of the material facilitates the subsequent transfer of the shape and size of the selected guide to the implant material. Handling is particularly easy because the plastically deformable material can be shaped manually at room temperature.

Claims

[1] Doctrine (10) for the reconstruction of a leaflet of an aortic valve, characterized by , that the teaching (10) is made of a material that can be plastically deformed under manual force. [2] Teaching (10) according to any of the preceding claims, characterized by that the teaching material is made from a biocompatible material. [3] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) is made of a sterilizable material. [4] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) is made of a material with a flexibility of more than 10 degrees. [5] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) is made of flexible steel, flexible aluminium or flexible plastic. [6] Teaching (10) according to any of the preceding claims, characterized by, that the teaching (10) is made of a nickel-titanium alloy. [7] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) is made of a memory alloy. [8] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) has a thickness (d) in the range of 0.05 mm to 2 mm, advantageously a thickness (d) in the range of 0.25 mm to 0.45 mm, preferably a thickness (d) in the range of 0.30 mm to 0.36 mm, for example a thickness (d) of 0.33 mm. [9] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) has a width (b) in the range of 15 mm to 40 mm. [10] Teaching (10) according to any of the preceding claims, characterized by that the teaching (10) has at least one, preferably several, in particular three, recesses (15) on its outer circumference. [11] Teaching (10) according to any of the preceding claims, characterized by , that the teaching (10) has atraumatically rounded edges. [12] Set of several teachings (10) according to one of the preceding claims in different sizes.

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