Medical instrument for dilating bony structures

Abstract

Medical instrument for dilating bony structures, comprising a shaft (2) at the distal end of which a tool tip (4) consisting of several radially outwardly pivotable segments (5) is arranged, and a handle (3) at the proximal end of which the handle (3) and the tool tip (4) are operatively connected to each other via an actuating element (7) whose distal end (8) is thickened, such that by actuating the handle (3) the pivotable segments (5) of the tool tip (4) can be adjusted between a closed position resting against the actuating element (7) and a radially outwardly pivoted working position, wherein the distal end (8) of the actuating element (7) projects beyond the pivotable segments (5) of the tool tip (4) in a distal direction and the distal end (8) of the actuating element (7) is wedge-shaped.that the distal end (8) widens conically from a distal tip (8a) proximally towards the distal end of the pivotable segments (5) of the tool tip (4), characterized in that a spherical thickening (8b) is formed on the actuating element (7) in a proximal direction behind the wedge-shaped distal end (8) of the actuating element (7), and that the pivotable segments (5) are pivotably mounted about a pivot axis (6) on the proximal end of the tool tip (4).

Description

[0001] The invention relates to a medical instrument for dilating bony structures, comprising a shaft at the distal end of which a tool tip consisting of several radially outwardly pivotable segments is arranged and at the proximal end of which a handle is arranged, wherein the handle and the tool tip are operatively connected to each other via an actuating element, the distal end of which is thickened, such that by actuating the handle the pivotable segments of the tool tip can be adjusted between a closed position resting against the actuating element and a radially outwardly pivoted working position.

[0002] The dilation instruments according to the invention are used, for example, in endoscopic ENT surgery to widen a patient's frontal sinuses and remove bony adhesions in the frontal sinus.

[0003] A medical dilation instrument of this type is known, for example, from EP 2 245 990 A1.

[0004] The dilation instrument known from patent US 6,436,119 B1 has a shaft at the distal end of which a tool tip consisting of several radially outwardly expandable segments is arranged and at the proximal end of which a handle is arranged, wherein the handle and the tool tip are operatively connected to each other via an actuating element, the distal end of which is thickened, such that by actuating the handle the expandable segments of the tool tip can be adjusted between a closed position resting against the actuating element and a radially outwardly pivoted working position.

[0005] From European patent application EP 2 245 990 A1, a dilation instrument is known which has an actuating element with a spherical tip, by means of which the pivotable segments of the tool tip are pivoted from the inside to the radial outside when the actuating element is moved distally. In this known dilation instrument, it is stipulated that the pivotable segments of the tool tip, in the closed position of the tool tip, completely enclose the distal end of the actuating element.

[0006] Instruments for dilating cardiac vessels are also known, which use pivotable segments to widen vessels and puncture vascular occlusions. However, these known medical instruments for dilating vessels are designed to transmit only minimal forces to prevent injury to the vessels being dilated. They are not suitable for dilating bony adhesions, such as those found in the frontal sinuses.

[0007] Based on this, the invention aims to create a dilation instrument that, with sufficient stability, allows for sensitive operation.

[0008] The solution to this problem according to the invention is characterized in that the distal end of the actuating element projects beyond the pivotable segments of the tool tip in a distal direction, the distal end of the actuating element is wedge-shaped such that the distal end widens conically from a distal tip proximally towards the distal end of the pivotable segments of the tool tip, a preferably spherical thickening is formed on the actuating element in a proximal direction behind the wedge-shaped distal end of the actuating element, and the pivotable segments are mounted pivotably about a pivot axis at the proximal end of the tool tip.

[0009] By relocating the distal end of the actuating element in an axial direction in front of the distal end of the pivotable segments of the tool tip according to the invention, it is possible to widen the tissue slightly via the thickened distal end of the actuating element before the actual dilation takes place via the pivotable segments of the tool tip.

[0010] In a preferred embodiment of the invention, it is further proposed that, in the closed position of the pivotable segments, the outer contour of the wedge-shaped distal end of the actuating element essentially continues in the outer contour of the pivotable segments in order to make it as easy as possible to slide the dilatation instrument into the surgical area.

[0011] To form the dilation mechanism, a preferred embodiment of the invention proposes that a receiving space for the thickening arranged on the actuating element be formed inside the tool tip formed by the individual segments, wherein the inner contour of the individual segments of the tool tip is designed such that when the position of the thickening of the actuating element is displaced in the proximal direction, the segments pivot radially outwards. By displacing the actuating element, which is advantageously designed as a pull or push rod, in the proximal direction of the shaft, the pivotable segments of the tool tip are pressed radially outwards.

[0012] In a practical embodiment of the invention, it is further proposed that the tool tip and the distal end of the actuating element can be covered with an elastic plastic coating to prevent tissue from entering the dilation mechanism.

[0013] When using the plastic sheath spanning the tool tip and the wedge-shaped distal end of the actuating element, it is particularly advantageous that the wedge-shaped distal end of the actuating element extends beyond the pivotable segments of the tool tip in a distal direction, since the wedge-shaped distal end of the actuating element provides a counter-support for the elastic plastic sheath, thereby preventing overstretching and damage to the plastic sheath.

[0014] Furthermore, the invention proposes that the pivotable segments of the tool tip can be moved from the open position of the tool tip back to the closed position by means of the elastic plastic casing. In this embodiment, the restoring force of the elastic plastic casing is used to move the tool tip back to the closed position after the pivotable segments have spread open and the plastic casing has stretched.

[0015] According to the invention, the elastic plastic coating is designed as a proximally open covering, with a circumferential sealing element formed at its proximal edge.

[0016] Advantageously, the sealing element is designed as a circumferential thickening that can be fixed in a corresponding circumferential groove of the tool tip.

[0017] Since the tool tip is subject to constant wear, especially when removing bony growths, the invention proposes that the tool tip be detachably connected to the shaft.

[0018] According to the invention, the assembly and disassembly of the instrument can be facilitated by the fact that the part of the actuating element mounted in the tool tip is detachably coupled to the part of the actuating element mounted in the shaft via a coupling mechanism.

[0019] Further features and advantages of the invention will become apparent from the accompanying drawings, in which an embodiment of a medical dilation instrument according to the invention is shown only by way of example, without limiting the invention to this embodiment. The drawings show: Fig. 1 a schematic partially cut-away side view of a medical dilation instrument according to the invention; Fig. 2 an enlarged view of detail II, showing the tool tip with plastic coating in the closed position and Fig. 3 a view according to Fig. 2, however showing the tool tip in the open position.

[0020] The image Fig. A schematically depicted medical dilation instrument 1 consists essentially of a hollow shaft 2, at the proximal end of which a handle 3 is arranged, which in the illustrated embodiment comprises a rigid handle part 3a and a handle part 3b that is pivotable relative to the rigid handle part 3a. A tool tip 4 is arranged at the distal end of the shaft 2, which, in particular, is made of Fig. 3 can be seen, consisting of several segments 5 which are mounted at the proximal end of the tool tip 4 so as to be pivotable radially outwards about pivot axes 6.

[0021] As further from Fig. As can be seen in Figure 1, the tool tip 4 and the pivotable handle part 3b of the handle 3 are operatively connected to each other via an actuating element 7, designed as a pull rod and axially displaceable within the hollow shaft 2, such that adjusting the handle part 3b of the handle 3 pivots the segments 5 of the tool tip 4 from the closed position (solid representation according to Figure 1). Fig. 1 as well as Fig. 2) into the open position (dashed representation according to Fig. 1 as well as Fig. 3) or vice versa. The corresponding position of the pivotable handle part 3b of the handle 3 is shown in the illustration. Fig. 1 is also shown as solid (for the closed position) and dashed (for the open position).

[0022] As an alternative to the depicted design of the actuating element 7 as a pull rod, it is of course also possible to design the mechanics of the dilatation instrument 1 in such a way that the actuating element 7 can be designed as a push rod.

[0023] In the illustrated embodiment, the tool tip 4 consists of four segments 5, which are pivotably mounted at the proximal end of the tool tip 4, offset by 90° relative to each other. Of course, it is also possible to construct the tool tip 4 from more or fewer segments 5, for example, from three segments 5, which are pivotally mounted at the proximal end of the tool tip 4, offset by 120° relative to each other.

[0024] As from Fig. 2 and Fig. As can be seen in Figure 3, the distal end 8 of the actuating element 7 is wedge-shaped and extends beyond the pivotable segments 5 of the tool tip 4 in both the closed and pivoted positions in the distal direction.

[0025] The wedge-shaped distal end 8 of the actuating element 7 is designed such that the distal end 8 widens conically from a distal tip 8a proximally towards the distal end of the pivotable segments 5 of the tool tip 4. In the closed position of the pivotable segments 5, the outer contour of the wedge-shaped distal end 8 of the actuating element 7 essentially continues into the outer contour of the pivotable segments 5, in order to allow the dilation instrument 1, with the tool tip 4 leading, to be inserted atraumatically into the surgical field, for example, a frontal sinus.

[0026] By shifting the wedge-shaped distal end 8 of the actuating element 7 in an axial direction in front of the distal end of the pivotable segments 5 of the tool tip 4, it is possible to widen the tissue slightly via the wedge-shaped thickened distal end 8 of the actuating element 7 before the actual dilation takes place via the pivotable segments 5 of the tool tip 4.

[0027] To pivot the segments 5 into the open position of the tool tip 4, a preferably spherical or conical thickening 8b is formed on the actuating element 7 in the proximal direction behind the wedge-shaped distal end 8 of the actuating element 7. The inner contour of the segments 5 is designed correspondingly to this thickening such that, in the closed position of the tool tip 4, a receiving space 9 for the thickening 8b of the actuating element 7 is formed inside the tool tip 4. In the illustrated embodiments, this receiving space 9 is conically narrowed towards the proximal end of the segments 5, so that when the actuating element 7 is retracted proximally, the segments 5 are pressed radially outwards into the open position of the tool tip 4 by the thickening 8b of the actuating element 7, which runs against the conical narrowing.

[0028] Since the tool tip 4, or the pivotable segments 5 of the tool tip 4, are subject to a certain amount of wear during use, the illustrated embodiments of the dilatation instrument 1 are designed such that the tool tip 4 can be fixed to the shaft 2 via a coupling mechanism 10 in an interchangeable manner.

[0029] The same applies to the in Fig. In the embodiment shown in Figure 2, the part of the actuating element 7 mounted in the tool tip 4 is detachably coupled to the part of the actuating element 7 mounted in the shaft 2 via a coupling mechanism 10. Of course, it is also possible to manufacture the actuating element 7 in one piece so that it can be inserted distally into the open tool tip 4 and the shaft 2.

[0030] To prevent tissue from entering the dilation mechanism, it is advantageous in practice to cover the entire distal end of the dilation instrument 1, namely the distal end 8 of the actuating element 7 and pivotable segments 5 of the tool tip 4, with an elastic plastic covering 11, as shown in Fig. 2 and Fig. Figure 3 is shown. However, even without such a coating, the described expansion mechanism can be used without any problems, as the simple and stable design allows for good and quick cleaning of all components.

[0031] As from Fig. 2 and Fig. As can be seen in Figure 3, the plastic covering 11 is designed as a proximally open coating that can be pulled over the tool tip 4 from the distal end. At its proximal end, the plastic covering 11 has a circumferential sealing element 12 that seals against the tool tip 4 to prevent tissue and / or liquid from penetrating under the plastic covering 11 and thus into the interior of the tool tip 4. In the illustrated embodiment, the sealing element 12 is designed as a circumferential, bead-shaped thickening that can be secured in a corresponding circumferential groove 13 of the tool tip 4.

[0032] Furthermore, securing the plastic covering 11 in the groove 13 has the advantage of preventing the plastic covering 11 from being stripped off the tool tip 4 when the dilating instrument 1 is withdrawn in an axial direction.

[0033] In addition to protecting the tool tip 4 against contamination, the elastic plastic casing 11 can be used to return the pivotable segments 5 of the tool tip 4 from the open position back to the closed position. In this configuration, the restoring force of the elastic plastic casing 11 is used to return the tool tip 4 to the closed position after the pivotable segments 5 have spread and the plastic casing 11 has stretched, as soon as the spherical thickening 8b of the actuating element 7 no longer pushes the pivotable segments 5 of the tool tip 4 into the open position.

[0034] Especially when using the plastic covering 11 covering the distal end of the dilation instrument 1, it is advantageous that the wedge-shaped distal end 8 of the actuating element 7 extends beyond the pivotable segments 5 of the tool tip 4 in both the closed and pivoted positions in the distal direction, since the wedge-shaped distal end 8 of the actuating element 7 provides a counter-support for the elastic plastic covering 11, thereby preventing overstretching and damage to the plastic covering 11.

[0035] In both the closed and open positions of the dilation instrument 1, the tip 8a of the wedge-shaped distal end 8 of the actuating element 7 always forms the foremost distal end of the dilation instrument 1, against which the plastic sheath 11 rests in a form-fitting manner. When pressed against the tissue to be dilated, the wedge-shaped distal end 8 thus provides direct support for the plastic sheath 11, preventing it from being compressed or overstretched.

[0036] The dilation instrument 1 described above is used in endoscopic surgery as follows: Based on the illustrations Fig. 1 (solid line) and Fig. In the closed position of the tool tip 4 shown in Figure 2, the dilatation instrument 1 is inserted into the surgical area, in particular the frontal sinus of a patient, leading the wedge-shaped thickened end 8 of the actuating element 7, in order to subsequently widen constricted areas.

[0037] To widen constricted areas of the surgical field, which also includes the removal of bony adhesions, the surgeon moves the pivotable part 3b of the handle into the Fig. The position shown in dashed lines represents the position by which the actuating element 7, coupled to this handle part 3b, is pulled proximally. Distally, the retraction of the actuating element 7 proximally causes the segments 5 of the tool tip 4 to move radially outwards through the spherical thickening 8b of the actuating element 7 into the position shown in the figures. Fig. 1 (dashed line) as well as Fig.3 shown open working position of the tool tip 4 can be pivoted.

[0038] In this design, the mechanical spreading force is based purely on the force transmission via the leverage forces used.

[0039] A dilation instrument 1 designed as described above is characterized by the fact that the dilation mechanism is very resistant due to the mechanism being controlled entirely via levers and pivot points, and furthermore enables the surgeon to work sensitively, since the force introduced via the handle 3 arrives in the operating area essentially without play. Reference symbol list 1 dilation instrument 2 shaft 3. Handling 3a rigid handle part 3b swiveling handle part 4 Tool tip 5 segments 6 swivel axes 7 Actuating element 8 distal end 8a Peak 8b Thickening 9 Recording room 10 Coupling mechanism 11 Plastic coating 12 Sealing element 13 Nut

Claims

[1] Medical instrument for dilating bony structures, comprising a shaft (2) at the distal end of which a tool tip (4) consisting of several radially outwardly pivotable segments (5) is arranged and at the proximal end of which a handle (3) is arranged, wherein the handle (3) and the tool tip (4) are operatively connected to each other via an actuating element (7) whose distal end (8) is thickened, such that by actuating the handle (3) the pivotable segments (5) of the tool tip (4) can be adjusted between a closed position resting against the actuating element (7) and a radially outwardly pivoted working position, wherein the distal end (8) of the actuating element (7) projects beyond the pivotable segments (5) of the tool tip (4) in a distal direction and the distal end (8) of the actuating element (7) is wedge-shaped,that the distal end (8) widens conically from a distal tip (8a) proximally towards the distal end of the pivotable segments (5) of the tool tip (4), characterized by , that in a proximal direction behind the wedge-shaped distal end (8) of the actuating element (7) a spherical thickening (8b) is formed on the actuating element (7) and that the pivotable segments (5) are mounted pivotably about a pivot axis (6) on the proximal end of the tool tip (4). [2] Medical instrument according to claim 1, characterized by , that in the closed position of the pivotable segments (5) the outer contour of the wedge-shaped distal end (8) of the actuating element (7) continues essentially in the outer contour of the pivotable segments (5). [3] Medical instrument according to claim 1, characterized by, that inside the tool tip (4) formed by the individual pivotable segments (5) a receiving space (9) for the thickening (8b) arranged on the actuating element (7) is formed, wherein the inner contour of the individual pivotable segments (5) of the tool tip (4) is designed such that when the position of the thickening (8b) of the actuating element (7) is displaced in a proximal direction, the segments (5) pivot radially outwards. [4] Medical instrument according to any one of claims 1 to 3, characterized by , that the tool tip (4) and the distal end (8) of the actuating element (7) can be covered with an elastic plastic covering (11). [5] Medical instrument according to claim 4, characterized by, that the pivotable segments (5) of the tool tip (4) can be moved from the open position of the tool tip (4) back to the closed position of the tool tip (4) by means of the elastic plastic covering (11). [6] Medical instrument according to claim 4 or 5, characterized by , that the elastic plastic covering (11) is designed as a proximally open coating, at the proximal edge of which a circumferential sealing element (12) is formed. [7] Medical instrument according to claim 6, characterized by , that the sealing element (12) is designed as a circumferential thickening which can be fixed in a corresponding circumferential groove (13) of the tool tip (4). [8] Medical instrument according to any one of claims 1 to 3, characterized by, that the part of the actuating element (7) mounted in the tool tip (4) is detachably coupled to the part of the actuating element (7) mounted in the shaft (2) via a coupling mechanism (10).

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