Medical guide instrument, medical instrument set, medical device, and medical method
Patent Information
- Application Number
- JP2024556627
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-30
- Filing Date
- 2023-03-27
- Publication Date
- 2025-04-15
Smart Images
Figure 2025510814000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a medical guide instrument for a medical electrode for positioning the electrode on a spinal nerve, in particular on a spinal ganglion, within the spinal canal.Furthermore, the present invention relates to a medical instrument set, a medical device, and a medical method. [Background technology]
[0002] Spinal cord stimulation has become an important pillar of chronic pain treatment in recent decades. From here, stimulation of the dorsal root ganglion, i.e. the dorsal root ganglion of the spinal cord, has emerged as a new technique for the treatment of monoradicular pain, especially of peripheral origin, of the upper and lower extremities. Stimulation of the dorsal root ganglion is a new and effective form of treatment for pain conditions involving one or more different nerve roots.
[0003] A common method involves implanting electrodes into the patient's spinal canal through intravertebral access. In this case, multiple electrodes are pushed (epidurally) into the patient's spinal canal to the desired dorsal root ganglion. However, this is often difficult in patients with epidural scars, and these scars prevent the electrodes from migrating, often causing undesirable deflection, especially since the electrodes are designed to be flexible for use in contacting the dorsal root ganglion. In particular, in the aforementioned patient population, it is not possible to reliably and quickly place the electrodes in the desired location using current devices and methods. Summary of the Invention [Problem to be solved by the invention]
[0004] SUMMARY OF THE PRESENT EMBODIMENT The object of the present invention is therefore to obviate the disadvantages of the prior art and in particular to allow better positioning of the electrodes. [Means for solving the problem]
[0005] The problem of the invention is solved by means of a medical guide instrument of the type mentioned at the beginning, which has a distal feed tube for accommodating an electrode, a first portion of the feed tube being curved when the guide instrument is in the insertion position and which is substantially straight when the guide instrument is in the feed position.
[0006] The object of the present invention is further achieved by a medical instrument set comprising a medical guide instrument according to the present invention, a medical electrode with at least one electrically conductive contact surface and a conductor connected to said electrode.Furthermore, the present invention is achieved by a medical device comprising a medical guide instrument according to the present invention and a medical endoscope, whereby said guide instrument can be accommodated in a working channel of the endoscope.
[0007] Finally, the invention is solved by a medical method for positioning a medical electrode on a spinal nerve by means of a medical guide instrument according to the invention, comprising the following steps: preparing access to the spinal nerve, introducing the medical guide instrument into a delivery position to position the electrode on the spinal nerve, actuating the insertion position of the medical guide instrument, and inserting the electrode through the medical guide instrument and through its delivery tube until the electrode is positioned on the nerve.
[0008] The invention is based on the basic idea that the guide instrument according to the invention ensures a reliable guidance of a medical electrode, particularly in the body of a patient during a surgical procedure. Scar tissue, particularly epidural, of the patient, which often leads to an undesirable deflection of the electrode when using known guide instruments, can be overcome by a defined guidance of the electrode through the guide instrument according to the invention in the insertion position, so that the electrode can safely and quickly reach its intended place of use and continue the planned pain treatment. In the present invention, the insertion position of the guide instrument refers to the position at which the electrode can be pushed through the guide instrument to reach the defined place. This is done in the present invention through a feed tube, the first part of which is curved. In the feed position, the guide instrument can be positioned particularly easily at the predefined insertion place, particularly due to the linear design of the feed tube in the feed position.
[0009] In the feed position, the first part of the feed tube is formed coaxially, which in the present invention refers to the (axial) extension direction of the guide instrument according to the invention. In the present invention, the distal direction refers to the patient direction and the proximal direction refers to the user / operator direction. In a virtual three-dimensional cylindrical coordinate system, the axial direction coincides with the extension direction of the guide instrument, while the radial direction, like the circumferential direction, is perpendicular to this axial direction.
[0010] The delivery tube of the guide instrument may be formed as a particularly flexible (hollow) catheter having at least one (hollow) cylindrical section.
[0011] In the insertion position of the guide instrument, the curvature of the first section of the feed tube can be user-defined, in particular can be user-defined and variably, preferably manually adjustable. The curvature of the feed tube in the insertion position of the guide instrument can have a predetermined curvature axis and / or a predetermined curvature radius, in particular between 6 mm and 15 mm, preferably between 9 mm and 12 mm. In particular, the curvature axis is perpendicular to the axial direction and / or is located in a horizontal plane.
[0012] The first portion is preferably located in a distal region of the delivery tube, e.g., at the distal end, which is preferably configured to be flexible, in order to precisely deflect the electrode as soon as possible after it emerges from the guide instrument.
[0013] The guide instrument can be switched between the feed position and the insertion position by a particularly linear pushing-out of the feed tube, so that the guide instrument can be switched between the feed position and the insertion position in a structurally simple manner.
[0014] The guide instrument preferably comprises at least one actuator, by means of which the guide instrument can be placed in an insertion position and in particular in a feed position. For ease of manipulation, the actuator is preferably at least partially corrugated on its user-facing surface. The actuator can be configured to be manually operable and / or linearly movable and / or rotatable. The feed tube can be linearly movable by the actuator, so as to be placed in the insertion position and / or in the feed position.
[0015] In an advantageous embodiment of the invention, the actuator is formed as a slider, in particular a linear slider, in order to allow a particularly simple switching of the guide instrument from the feed position to the insertion position. For this purpose, the actuator can be guided as a slider in a recess of the feed tube assigned to it, which recess is formed in particular as an oblong hole. Preferably, the actuator is connected to the feed tube at least indirectly, in particular directly and / or in a mating manner, so that a particularly axial movement of the feed tube can be effected by operating the actuator. To connect the actuator to the feed tube in a particularly direct mating manner, the actuator preferably has at least one protrusion oriented towards the feed tube, which protrusion engages in a mating manner in at least one, in particular radial, recess of the guide tube. As an alternative, the actuator can also have a recess, into which a protrusion of the feed tube oriented towards this recess engages.
[0016] The actuator can be associated with a guide part, which is connected to the proximal grip part, in particular by a mating connection, in particular by a screw connection. This configuration of the guide part and the grip part allows a functional-spatial division of the guide instrument, in accordance with the invention, in which the guide instrument can be manipulated by the grip part and the insertion position of the guide instrument can be actuated by the guide part. The grip part can be removably connected to the guide part.
[0017] Preferably, the feed tube has at least one straight, in particular coaxial, section, the length of which is in particular between 250 mm and 350 mm. In order to make the straight section straight, in particular at the insertion position of the guide instrument, the straight section is made in particular rigid. Alternatively, the straight section can be made flexible. The feed tube is preferably made in one piece. In this embodiment, the feed tube can be made of several elements, which are connected in one piece, in particular welded to each other.
[0018] In an alternative embodiment, the feed tube can be formed in several parts, in particular in two parts, in which case the first distal part of the feed tube can comprise a first part that is bendable in the sense of the present invention. The second proximal part of the feed tube can comprise in particular a straight section, which extends for example over at least 75% of the total length of the feed tube. The first part of the guide tube can be matingly connected to its second part, in which for example a particularly rectangular recess of the first part engages with a complementary shaped protrusion of the second part, so that a mating connection is formed between the first and second parts of the feed tube along the extension direction of the feed tube. In the sense of the present invention, the first part of the feed tube can also be welded together with the second part. The second part of the feed tube can have a recess, in particular as mentioned above, for a mating connection with the actuator. At least a part of the feed tube can comprise a component made of plastic material or can consist of plastic material.
[0019] In an advantageous embodiment, the guide instrument can exist autonomously at the insertion position without the application of external forces, which is achieved, for example, by the feed tube comprising, at least in part, in particular in the first part, at least one component made of a flexible material, for example a shape memory alloy, in particular a nickel-titanium alloy, for example Nitinol, and / or at least one component made of a plastic, in particular polyethylene (PE).
[0020] The feed tube can be at least partially, especially in the distal region, surrounded by a particularly rigid guide tube, which is designed, for example, as a hollow cylinder and / or is oriented parallel to the feed tube, especially coaxially thereto. The length of the guide tube corresponds in particular to the length of the straight section of the feed tube, the axial length of the guide tube being preferably between 250 mm and 350 mm. The feed tube and / or the guide tube preferably have a circular cross section, the diameter of which is in particular between 3 mm and 4 mm, preferably 3.5 mm. In an advantageous development of the invention, the feed tube is arranged in a close-fitting manner inside the guide tube, in which case the feed tube is particularly axially displaceable relative to the guide tube. The guide tube can at least partially comprise components made of metal, preferably stainless steel, and / or a flexible material, preferably plastic.
[0021] In order to guide the medical electrode, the guide instrument preferably has an inner bore for accommodating the electrode, in which case the inner bore extends in particular over the entire axial length of the guide instrument. The inner bore is in particular oriented coaxially. The guide instrument is in particular designed to be reusable or, alternatively, as a disposable instrument. In particular, if the guide instrument is designed as a disposable instrument, the feed tube can be made of a plastic material.
[0022] In another advantageous embodiment of the invention, the feed tube is at least indirectly connected to the actuator via a pull wire, for example at the proximal end region of the feed tube and / or at the top of the feed tube, which can be connected to a base. Preferably, the actuator, in particular designed as a slider, is connected to the base.
[0023] The feed tube and / or the guide tube may have an elliptical cross section, in which case preferably the diameter of the feed tube and / or the guide tube is 2.5 mm to 3.5 mm in the first semi-major axis of the cross section and 1.5 mm to 2 mm, in particular 1.7 mm, in the second semi-major axis of the cross section. The outer surface of the guide instrument, in particular the part facing the actuator, has a flat portion, which extends in particular over an azimuthal range of 30° to 90°. This flat portion allows a defined position of the guide part, for example when the guide part is placed on the operating table. This prevents the guide instrument from being accidentally dropped and thus contaminated.
[0024] In another advantageous embodiment of the invention, the guide instrument is designed as a disposable instrument. The first part of the feed tube can be arranged axially centrally to allow better guidance of the electrode in the patient's spinal canal.
[0025] Preferably, an adapter part is provided with an inner bore for receiving the electrode in order to facilitate the introduction of the electrode into the guide instrument. More preferably, the feed tube passes at least partially through this adapter part in order to further improve the introduction of the electrode. The inner bore has in particular a circular cross section and / or is coaxially oriented. This adapter part is preferably arranged in the proximal region of the guide instrument or in the distal guide part of the guide instrument. This guide part can have a grip part for improving the maneuverability of the guide instrument. This adapter part can be arranged in particular at the axial height of the grip part.
[0026] Preferably, the inner bore of the adapter part is radially widened towards the proximal and / or distal end face of the adapter part, in particular the inner bore is continuously widened towards one of the end faces, so that a for example funnel-shaped shape of the inner bore is obtained.
[0027] The bore of the adapter part preferably has a transverse connecting piece arranged at a finite angle to the longitudinal axis of the guide instrument, the connecting piece having a bore for receiving an electrode, the bore of the connecting piece being connected to the bore of the adapter part. In this way, the electrode can be introduced into the bore of the adapter part at a finite angle, e.g. other than 0°, so that the axial view of the guide instrument is not impaired by the electrode. At least one component of the guide instrument can be visualized, e.g. by X-ray, so that the current position of the guide instrument can be determined during the surgical procedure. The guide instrument, in particular its jacket, can have at least one hole, preferably coaxially oriented, which reduces the weight of the guide instrument according to the invention and ensures easier application, especially when used over long periods of time.
[0028] At least one conductive contact surface of the electrode of the instrument set can be formed, in particular in the distal region of the electrode. The electrode is preferably cylindrical and has in particular at least two, preferably eight, contact surfaces, which are arranged, for example, one behind the other in the axial direction. The electrode can have up to 16 contact surfaces. In order to prevent short circuits, a non-conductive insulating surface can be arranged between two conductive contact surfaces. At least one, in particular the distal part, of the conductor electrically connected to the electrode can be designed to be flexible and / or at least one part of the conductor can be designed to be rigid. In this way, the electrode and / or the conductor electrically connected to the electrode can be adapted, in particular, to the first part of the curved feed tube at the insertion position of the guide instrument. The electrode and / or the electrical conductor can be cylindrical, for example, with an outer diameter of 0.5 mm to 1.5 mm. The length of the conductor is preferably 400 mm to 800 mm. The electrode can be connected to an electric pulse generator, in particular the contact surfaces of the electrode can be controlled independently of each other by the pulse generator.
[0029] The medical device in particular comprises a medical instrument set with a medical guide instrument according to the invention and / or can further be deployed such that the guide instrument, in particular its feed tube and / or guide tube, can be accommodated in the working channel of an endoscope. The endoscope can have a flushing connector and / or an optical imaging device, in particular a camera. In particular, the endoscope is configured as a disposable instrument for one-time use and / or has at least one disposable component. In an alternative development of the invention, the endoscope is configured to be reusable.
[0030] The method according to the invention can be performed with the medical guide instrument according to the invention and / or with the medical instrument set according to the invention and / or with the medical device according to the invention. In a further development of the method according to the invention, access to the spinal nerves, in particular the epidural space, is performed transluminally, i.e. through the intervertebral foramen as a (lateral) intervertebral foramen between two adjacent vertebral bodies, and / or intralaminarly, i.e. through a (anterior) posterior interlaminar window between two adjacent vertebral bodies.
[0031] The introduction of the medical guide instrument can be performed by introducing a medical device according to the invention. Furthermore, the medical guide instrument can be introduced under visual inspection and / or under X-ray control.
[0032] The electrode can be placed on the ganglion, particularly the dorsal ganglion of the spinal nerve, to ensure effective application of the electric pulse. The electrode can be connected to an electric pulse generator after insertion, particularly after which the medical guide instrument and / or remaining components of the medical device can be removed from the surgical site. Preferably, the electrode can be placed on the spinal nerve and can be connected, for example, by multiple loops and / or fixation elements.
[0033] Further advantages and features of the invention will become apparent from the appended claims and the following description, in which an embodiment of the invention is explained in detail with reference to the drawings. [Brief description of the drawings]
[0034] [Figure 1] 1 is a side view of a first embodiment of a guide instrument according to the present invention. [Diagram 2] FIG. 2 is a plan view of the guide instrument according to FIG. 1. [Diagram 3] 2 is a longitudinal axial section through the guide instrument according to FIG. 1; FIG. [Figure 4] FIG. 2 is a cross-sectional view of the guide instrument according to FIG. 1. [Diagram 5] FIG. 5 is a detailed view of FIG. [Figure 6] FIG. [Figure 7] 2 is a guide instrument according to FIG. 1 in a feed position; [Figure 8] 8 is a guide instrument according to FIG. 7 in an insertion position. [Figure 9] 9 is a guide instrument according to FIG. 8 with an electrode inserted. [Figure 10] 13 illustrates another configuration of the delivery tube in the insertion position. [Figure 11] 13 illustrates another configuration of the delivery tube in the insertion position. [Figure 12] 13 illustrates another configuration of the delivery tube in the insertion position. [Figure 13] FIG. 10 is an overall view of the electrode of FIG. [Figure 14] The guide instrument of FIG. 9 is shown with an electrode and endoscope inserted. [Figure 15] 14 in the distal region of the feed tube. FIG. [Figure 16] FIG. 15 is a proximal perspective view of a guide instrument with an endoscope according to FIG. 14. [Figure 17] FIG. 2 is a side view of a guide instrument according to the present invention in a second embodiment. [Figure 18] FIG. 18 is a plan view of the guide instrument according to FIG. 17. [Figure 19] 18 is a longitudinal axial section of the guide instrument according to FIG. 17. [Figure 20]FIG. 18 is a perspective view from below, distally, of the guide instrument of FIG. 17. [Figure 21] 18 is a guide instrument according to FIG. 17 in a feed position. [Figure 22] 22 is a guide instrument according to FIG. 21 in an insertion position with an electrode to be inserted. [Figure 23] 23 is a guide instrument according to FIG. 22 with an electrode inserted therein. [Figure 24] 18 is a guide instrument according to FIG. 17 in an insertion position with an endoscope. [Diagram 25] FIG. 25 is an enlarged view of the guide instrument according to FIG. 24 in the distal region of the delivery tube. [Figure 26] FIG. 2 is a proximal perspective view of a guide instrument with an endoscope according to 24. [Figure 27] FIG. 13 is a side view of a third embodiment of a guide instrument according to the present invention with an endoscope. [Figure 28] FIG. 2 is a proximal perspective view of a guide instrument with an endoscope according to 27. [Figure 29] FIG. 13 is a proximal view of an implanted electrode connected to a pulse generator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] FIG. 1 shows a side view of a first embodiment of a guide instrument 10 according to the present invention, the guide instrument having a proximal jacket portion 11, an axially central gripping portion 12 and a distal guide portion 13.
[0036] The proximal jacket 11 is designed substantially as an axially oriented hollow cylinder with an inner bore 14 and an axial base 15 arranged therein, which is shown in particular in the longitudinal section of Fig. 3. The jacket 11 according to Fig. 2 has on its upper surface 16 a recess 17 with a part-circular cross section, which is surrounded on both sides by flats 16a each with a flat surface, so that the guide instrument 10 does not fall uncontrollably from the instrument table after being set down, but remains in a defined position. The jacket 11 is open towards its proximal end face 18, by means of which an adapter part 19 for introducing an electrode 20 can be inserted into the inner bore 14 and connected to the jacket 11.
[0037] In the connected state, the adapter part 19 engages in the proximal bore 14 of the jacket part 11 and proximally projects therefrom. The outer diameter of the adapter part 19 at its distal end is smaller than the inner diameter of the jacket part 11. The adapter part 19 has an axially penetrating bore 21 which is radially enlarged towards the proximal end face 22 of the adapter part 19 to facilitate the introduction of the electrode 20. The bore 21 of the adapter part 19 is also enlarged towards its distal end face 23 to facilitate the introduction of the feed tube 38, as will be described below. In the illustrated embodiment, the electrode 20 has an outer diameter of 1.4 mm. The diameter of the bore 21 is slightly larger than the diameter of the electrode 20 to be inserted, so that this electrode can pass through the bore 21 and move freely axially therein, as will be described below.
[0038] The proximal jacket 11 of the guide instrument 10 is connected in the distal direction to the gripping part 12, with a distal cylindrical plug 24 of the jacket 11 engaging in an inner bore 25 of the gripping part 12. The gripping part 12, like the jacket 11, is designed as an axially oriented cylinder and has an oblong recess 26 facing upwards according to the plan view in FIG. 2, which opens into the inner bore 25 of the gripping part 12. The recess 26 serves as a guide for an actuator 27 arranged partly in the recess 26, which is designed as a slider for moving the guide instrument 10 in particular from the feed position to the insertion position, a manually operable linear slider 28 in the embodiment according to FIGS. 1 to 6, which will be explained further below. The linear slider 28 has a semicircular slider button 30 with a knurled surface 31 on the upper side 29 shown in FIG. 1 for improved maneuverability. The underside 32 of this linear slider 28 in Fig. 1 is provided with two rectangular projections 33, shown in longitudinal section in Fig. 3, which penetrate the recess 26 and the bore 25 of the gripping part 12 (see Figs. 1 and 3) so that the projections 33 protrude beyond the gripping part 12. The cross section of the gripping part 12 tapers towards its distal end face 34, while the cross section of the bore 25 does not change in the distal region 35 of the gripping part 12.
[0039] The distal guide part 13 has a rigid guide tube 36 made of stainless steel, which is inserted from the distal direction into the inner bore 25 of the grip part 12 and is connected thereto. In the embodiment of the guide instrument 10 according to Figs. 1-6, the axial length of the guide tube 36 protruding distally beyond the grip part is 1.5 mm. FR is in the range of 250 mm to 350 mm, measured from the distal end face 34 of the gripping portion 12 to the distal end face 37 of the guide tube 36. The guide tube 36 is designed as a hollow cylinder with a circular cross section, and the diameter of the guide tube 36 is 3.50 mm and does not vary over its axial length.
[0040] 3, a feed tube 38 is disposed inside the guide tube 36, and its axial length is longer than that of the rigid guide tube 36. The feed tube 38 engages with the inner space 39 of the guide tube 36, the inner bore 25 of the gripping part 12, the bore 14 of the jacket part 11, and the inner bore 21 of the adapter part 19, whereby in the insertion position of the guide instrument 10 shown in FIG. 3, the proximal end face 40 of the feed tube 38 is disposed inside the inner bore 21 of the adapter part 19, but does not completely penetrate it. Since the outer diameter of the feed tube 38 is almost the same as the inner diameter of the inner bore 21 of the adapter part 19, the feed tube 38 is disposed in a snug fit within the adapter part 19, but is axially movable therein.
[0041] The feed tube 38 has a shape memory alloy component, especially in its distal end region 41, so that the distal end region 41 of the feed tube 38 is designed to be flexible. In the embodiment of Figs. 1-6 showing the guide instrument according to the invention in the insertion position, the distal end region 41 of the feed tube 38 has a curvature directed upwards in Fig. 1, which is approximately 90° to the orientation of the guide tube 36, so that the distal end face 42 of the feed tube 38 is deflected upwards by approximately 9 mm-12 mm from the lower distal end face 37 of the guide tube 36. This corresponds to a radius of curvature of 9 mm-12 mm. In this respect, in the embodiment shown, this curved distal end region 41 of the feed tube 38 corresponds in the present invention to its first portion 41. Fig. 6 shows a detailed view of the flexible distal end region 41 of the feed tube 38. 3, the electrode 20 has an outer diameter of 1.40 mm and can be axially displaced through the feed tube 38. The electrode 20 has an outer diameter of 1.40 mm and can be axially displaced through the feed tube 38. The electrode 20 has an inner diameter of 1.40 mm and can be axially displaced within the feed tube 38. The electrode 20 has an outer diameter of 1.40 mm and can be axially displaced through the feed tube 38. The electrode 20 has an outer ...
[0042] As can be seen in particular from figures 3 to 5, downwardly directed projections 33 of the slider button 30 engage in axially oriented transverse recesses 42b of the feed tube 38, so that the slider button 30 and the linear slider 28 are integrally connected axially to the feed tube 38 as a quick-releasable snap-in connection. Figure 4 shows a cross section of the guide instrument 10 according to figure 3 at the axial height of the linear slider 28. Figure 5 shows a detailed view of the radial center of figure 4. The projections 33 of the slider button 30 penetrate in particular the recesses 26 of the gripping part and act as snap hooks under a respective laterally outward force, with which the slider button 30 is connected clampingly, i.e. frictionally, to the gripping part 12.
[0043] When the slider button 30 is moved by the user in a proximal direction from the position shown in Figure 3, the feed tube 38 follows this axial movement. As a result, the distal end face 42 of the feed tube 38 is retracted into the guide tube 36, so that the feed tube 38, due to its geometry and its flexible configuration, is completely and coaxially disposed within the guide tube 36. In this case, the proximal end face 40 of the feed tube 38 remains within the inner bore 21 of the adapter part 19. This arrangement is the feed position of the guide instrument 10 according to the present invention and is shown in Figure 7.
[0044] Now, if the slider button 30 is moved in the distal direction from the feeding position of the guide instrument 10 according to FIG. 7, the flexible feed tube 38 passes through the distal end face 34 of the rigid guide tube 36 and, after leaving the guide tube 36, is curved as already explained due to the shape memory alloy in the distal end region 41 (see FIG. 8). This arrangement is the insertion position of the guide instrument 10. In this insertion position of the guide instrument 10, the electrode 20 together with the electric conductor 43 connected thereto is introduced from the proximal side through the adapter part 19 into the inner space 39 of the feed tube 38 and, moving further distally, the electrode 20 finally passes through the distal end face 42 of the feed tube 38, which is here angled by approximately 90° with respect to the axial direction due to the curvature. This makes it possible to transport the flexible electrode 20 to the desired insertion location, which is not possible or is very difficult to achieve with known instruments that are rigid and linearly constructed.
[0045] FIG. 10 shows a two-part arrangement of the feed tube 38 with a distal first part 38a and a proximal second part 38b. In FIG. 10, the first part 38a is shown separated from the second part 38b. The first part 38a has a curved first part in the distal end region 41, which is provided with a number of material structures by a laser cutting process, as already explained. In FIG. 10, no external forces act on the distal end region 41 of the illustrated feed tube 38, so that this distal end region assumes a curved position on its own, as already explained. The proximal side of the first part 38a is provided with a rectangular recess 38c, which is shown in FIG. 10 in the sense of a cutout. From this recess 38c extends a milled axial slit 38d towards the proximal side, the lateral width of which is smaller than that of the recess 38c. The slit 38d extends from the rectangular recess 38c to the proximal end face 38e of the first part 38a. The first part 38a is made as a hollow cylinder at least in the region from the recess 38c to its proximal end face 38e.
[0046] The distal side of the second part 38b of the feed tube 38 is provided with a coaxially oriented cylindrical fitting 38f, the diameter of which is smaller than the inner diameter of the first part 38a. The second part 38a can thus be inserted into the first part 38a by means of the fitting 38f. For the mating connection of the second part 38b to the first part 38a, the fitting 38f has a rectangular projection 38g, in the sense of a protuberance, which is designed complementary to the recess 38c of the first part 38a. The fitting 38f is formed integrally with the shell 38h, the diameter of which is the same as that of the first part 38a. The proximal region of the shell 38h is provided with a recess 38i, through which the rectangular projection 33 of the actuator 27 can engage, so that the actuator 27 can be matingly connected to the feed tube 38. Starting from the representation according to FIG. 10, when the second part 38b is pushed towards the first part 38a, the stop 38f passes through the first part 38a until the projection 38g is at the same axial height as the recess 38c, so that the former (stop) penetrates into the latter (recess). The shape of the slit 38d in the first part 38a weakens the material strength, facilitating the mutual insertion of the two parts 38a and 38b. The engagement of the projection 38g into the recess 38c in a snap-in manner results in a releasable connection in the sense of a snap-in connection of the two parts 38a, 38b, so that the feed tube 38 as a whole is particularly axially movable. This state is shown in FIG. 11. FIGS. 10 and 11 essentially show the implementation of the connection of the two parts 38a, 38b by a snap-in connection. This mating connection is secured through the guide tube 36 (not shown in FIG. 10) so that after the feed tube 38 is inserted into the guide tube 36, a secure connection is assured during use even when subjected to mechanical stress.
[0047] 12 shows an alternative embodiment of the feed tube 38 which is made in one piece, which makes it possible to simplify the construction by avoiding the need to connect two separate parts 38a, 38b to each other. The connection between the feed tube 38 and the feed tube 36 pressed onto it is made by the recess 38i, as already mentioned above.
[0048] FIG. 13 shows an electrode 20, an electrical conductor 43 connected to the proximal side of the electrode 20, and an electrical pulse generator 44 connected to the conductor, in this case a pacemaker, which provides electrical energy for controlling the electrode 20. In the embodiment of FIG. 13, the electrode 20 is cylindrical and has six conductive contact surfaces 46 arranged axially one behind the other on its outer surface 45, which can be used to apply electrical pulses in a localized manner. Between two of the contact surfaces 46 is a non-conductive insulator 46a. Each contact surface 46 can be individually controlled by the pulse generator 44, and the electrical pulses have a predefined and fixed amplitude and frequency. The electrode 20 is flexible and is shown in a curved configuration in FIG. 13. In the embodiment of FIG. 13, the electrode 20 is shown in a flexible configuration.
[0049] FIG. 14 shows a medical device 49, including a guide instrument 10 according to the present invention substantially in the embodiment of FIGS. 1 and 2, an electrode 20 introduced therein with an electrical conductor 43, and an endoscope 50 in surgical use. According to this, the guide tube 36 of the guide instrument 10 is introduced into a coaxially oriented working channel 51 of the endoscope 50. The endoscope 50 accesses the patient's spinal canal 54 via a rigid working sleeve 52 distal to the endoscope 50, which does not protrude distally beyond the guide tube 36 and the feed tube 38 as well as the electrode 20, which is not shown in FIG. 14 for perspective reasons. In FIG. 14, the guide tube 36 of the guide instrument 10 together with the feed tube 38 is inserted through an intervertebral foramen 53 between two adjacent vertebral bodies, here two lumbar vertebral bodies 55, as an access to the patient's spinal canal 54, whereby the electrode 20 can be contacted with a dorsal root ganglion (not shown in FIG. 14) in the spinal canal 54. In contrast to the embodiment according to figures 1 and 2, this jacket 11 of the guide instrument does not have a recess 17 but only a flat part 16a on its upper side.
[0050] In Fig. 14, the guide instrument 10 is in the insertion position, so that the distal end region 41 of the feed tube 38 is curved as already explained, which is shown in particular by the detailed view of Fig. 15. The electrode 20 passing through the feed tube 38 is deflected corresponding to the curved distal end region 41. Furthermore, according to Fig. 15, the working sleeve 52 is cannulated on the distal side. According to Fig. 14, the endoscope 50 has a lateral irrigation connector 57 and a lateral light output 56, the latter allowing visualisation of the surgical field.
[0051] Figure 16 shows the medical device 49 of Figure 14 in an oblique cranial proximal view, with access to the spinal canal 54 being provided through an intravertebral window 58 between two lumbar vertebral bodies 55. In Figure 16, the guide instrument 10 is still in the insertion position, with the electrode 20 curved upwards approximately 90° within the spinal canal 54, contacting the dorsal root ganglion, not shown in Figure 16.
[0052] 17 shows a second embodiment of a guide instrument 10 according to the invention, designed as a disposable instrument for one-time use only. This guide instrument 10 has a proximal grip part 59 which is matingly connected to a distal guide part 60. The proximal outer contour of the grip part 59 is designed to be tightly wrapped and held by the user's hand, especially during manipulation. The actuator 27 is provided in the distal region 59a of the grip part 59 and, like the first embodiment of the guide instrument 10, is designed as a linear slider 28 with a slider button 30, which is also provided with a profile.
[0053] In Fig. 17-20, the linear slider 28 is in a proximal position corresponding to the insertion position of the guide instrument 10, in which the first distal part 41 of the feed tube 38 is angled. According to Fig. 17, the distal guide part 60 has a right-downward connecting part 61 with an inner bore 62, which serves as a lateral guide channel. This is also evident from the axial longitudinal section in Fig. 19. The diameter of the inner bore 62 is designed such that the electrode 20 shown in Fig. 17 can be inserted into the inner bore 62 with lateral play (see also Fig. 19). The inner bore 62 of the connecting part 61 is connected to the coaxial inner bore 63 of the guide part 60, so that the electrode 20 can be inserted through the inner bores 62, 63 finally into the inner space 39 of the feed tube 38, which in this case is connected to the guide part 60.
[0054] The feed tube 38 is elliptical in cross section and has a diameter of 2.50 mm to 3.50 mm in the transverse horizontal direction corresponding to a first semi-major axis, and a diameter of 1.70 mm in the transverse vertical direction corresponding to a second semi-major axis. In this embodiment, the feed tube 38 has an axial length l of 250 to 350 mm. ZR and the first curved portion 41, already described, having a curve of approximately 90°.
[0055] From the longitudinal section of the guide instrument 10 according to Fig. 19 it can be seen that the linear slider 28 is mounted so as to be linearly movable on the distal contact surface 65 of the gripping part 59. The contact surface 65 has a stop 67 in its distal end region 66 for the distal movement of the linear slider 28. The linear slider 28 according to Fig. 19 is in proximal contact with a seat 68 which in turn is in contact with a proximal end surface 69 of the recess 26 of the gripping part 59. This seat 68 is connected to a coaxially oriented pull wire 70 which passes through the recess 26 of the gripping part 59 and the inner bore 63 of the guide part 60 and is connected to the upper part 71 of the feed tube 38.
[0056] When the linear slider 28 is moved proximally from a distal position by a user, the resulting pulling of the pull wire 70 causes deflection of the upper portion 71 of the feed tube 38 connected to the pull wire 70, so that its distal end region 41 assumes the curved position shown in Figure 19. In this position, the electrode 20 pressed into the lateral bore 62 of the guide portion 60 is correspondingly deflected during further axial movement through the distal end region 41 of the feed tube 38. Figure 20 shows the guide instrument 10 of Figure 19 in an insertion position from a rear view.
[0057] FIG. 21 shows the guide instrument 10 of FIG. 17 in the feed position, i.e. with the linear slider 28 in the distal position, in which the distal end region 41 of the feed tube 38 is coaxially oriented. During the proximal movement of the linear slider 28, the seat 68 in contact with it also moves proximally, so that the pull wire 70 follows this movement. Since the pull wire 70 is connected to the upper part 71 of the feed tube 38 as already explained, the distal end region 41 of the feed tube 38 is erected by this movement of the linear slider 28 (see FIG. 22 which shows the guide instrument 10 in the insertion position). If the axial movement continues, the electrode 20 introduced in the connection part 61 will eventually protrude from the distal end face 42 of the feed tube 38, as shown in FIG. 23.
[0058] Figure 24 shows, similarly to figure 14, a device 49 according to the invention with a guide instrument 10 in a second embodiment with an endoscope 50, which embodiment has already been discussed in connection with figure 14. This guide instrument 10 is introduced in a known manner into the working channel 51 of the endoscope 50, as is also evident from the detailed view of figure 25. Here, the feed tube 38 emerges from the cannula working sleeve 52, the distal end region 41 being curved according to the insertion position of the guide instrument 10. According to figure 24, this device 49, shown similarly to figure 14, is introduced through the intervertebral foramen 53 in order to position the electrode 20 in the spinal canal 54.
[0059] 26, the device 49 according to the present invention of FIG. 25 is placed via intralaminar access through an intravertebral window 58 in the spinal canal 54, similar to FIG.
[0060] FIG. 27 shows a third embodiment of the medical guide instrument 10 according to the invention, which is inserted into the spinal canal 54 through the intervertebral foramen 53. As in the two previous embodiments, the guide instrument 10 of FIG. 27 has a distal feed tube 38, whose curved first portion 41 is arranged in this case not as a distal end region but in the axially central portion 41a. This axially central portion 41a is obliquely covered in FIG. 27 and is not shown. Due to this position of the first portion 41, the distal portion of the feed tube 38 also engages in the spinal canal 54. The jacket 11 is designed as a disposable endoscope, in which case the electrode 20 together with the conductor 43 and the feed tube 38 are introduced through the coaxial working channel 51 of the endoscope. The optical output 56 is connected by a connector 73 via a camera cable 72 to a camera head cable (not shown). The working sleeve 52 of the endoscope reaches into the spinal canal 54 through the intervertebral foramen 53, similar to the illustration in FIG. 24. By manipulating the actuator 27, it reaches the distal position shown in FIG. 27, which results in bending of the first part 41 of the feed tube 38 (here located axially centrally), so that the electrode 20 can be positioned in the spinal canal 54 in an already clear manner.
[0061] Figure 28 illustrates the guide instrument 10 of Figure 27, where access to the spinal canal 54 is provided through the previously described intravertebral window 58. Also illustrated in Figure 28 is the axially central portion 41a of the delivery tube 28.
[0062] After the electrode 20 has reached the desired position in the spinal canal, in particular contacting the dorsal ganglion, and the validity of the positioning of the electrode 20 has been verified, the medical guide instrument 10 and the remaining components of the device 49 can be removed. The proximal side of the conductor 43 connected to the electrode 20 is then connected to an electrical pulse generator 44, shown in FIG. 29, as already described in FIG. 13. This pulse generator 44 is designed to output electrical pulses periodically and continuously to the electrode 20 and can be implanted in the patient's body. For this purpose, the electrode 20 is placed, for example, on the fascia (not shown) using known fixation devices, with strain relief loops ensuring a stable hold of the electrode 20.
[0063] In the following, the method according to the invention will be explained using a first embodiment of a guide instrument 10 according to the invention according to FIGS. 1 to 9 and 13 to 16.
[0064] First, access is provided to the patient's spinal canal 54, for example via the intervertebral foramen 53 (FIG. 14) and / or the intravertebral window 58 (FIG. 16). Alternatively or additionally, access can be provided transluminally by puncturing the caudal portion of the foramen with a spinal needle (not shown).
[0065] A guidewire (not shown) is then placed and multiple dilators of successively larger diameters are pushed over this wire to open the tissue around the guidewire as atraumatically as possible. Finally, a working sleeve is inserted through the last dilator under continuous x-ray control.
[0066] The working sleeve 52 of the endoscope 50 has an inner lumen through which the endoscope 50 is inserted, the endoscope 50 having a working channel 51 for accommodating the guide instrument 10 according to the invention, in addition to an irrigation connector 57 and a light output 56. The guide instrument 10 is pushed through the working channel 51 of the endoscope 50 into a feed position until its distal end region 41 engages the spinal canal 54. The first portion 41 of the feed tube 38 of the guide instrument 10 is designed to be straight to allow rapid insertion into the patient's body.
[0067] After the guide instrument 10 has reached the desired location, the user actuates the actuator 27, i.e. in the specific embodiment, pushes the linear slider 28 from proximal to distal, which then pushes the feed tube 38 in the distal direction as well, so that the first portion 41 of the feed tube 38 protrudes beyond the rigid guide tube 36 and, depending on its material properties, assumes the curved position already described, and the guide instrument is then in its operating position.
[0068] In a next step, the electrode 20 together with the conductor 43 is introduced proximally into the guide instrument 10, more precisely into its adapter part 19, so that the electrode 20 emerges at the distal end face 42 of the curved delivery tube 38 and can thereby assume the desired position, for example in contact with a dorsal ganglion in the spinal canal 54. After the electrode 20 has assumed the desired position and its correct function has been verified, the guide instrument 10 is withdrawn together with the endoscope 50, so that finally only the electrode 20 remains inside the patient's body. The electrode 20 is connected proximally to an electric pulse generator 44, which is finally implanted in the patient, as already explained.
Claims
1. A medical guide instrument (10) for positioning an electrode (20) on a spinal nerve, in particular on a spinal ganglion, in a spinal canal (54), comprising: The guide instrument (10) has a distal delivery tube (38) for receiving the electrode (20); When the guide instrument (10) is in an insertion position, a first portion (41) of the delivery tube (38) is curved; When the guide instrument (38) is in a feed position, the first portion (41) of the feed tube (38) is substantially straight. A medical guide instrument (10).
2. 2. The medical guide instrument according to claim 1, characterized in that, in the insertion position of the guide instrument (10), the curvature of the first portion (41) of the feed tube (38) is defined by a user, in particular variably defined by a user, preferably manually adjustable.
3. 3. The medical guide instrument according to claim 1 or 2, characterized in that the first portion (41) is arranged in a distal region of the feed tube (38), in particular as a distal end region, and is preferably formed to be flexible.
4. 4. The medical guide instrument according to claim 1, wherein switching of the guide instrument (10) between the feed position and the insertion position can be performed by a particularly linear pushing-out of the feed tube (38).
5. The medical guide instrument according to any one of claims 1 to 4, characterized in that the guide instrument (10) has an actuator (27), and the insertion position of the guide instrument (10) can be obtained by using the actuator (27).
6. 6. The medical guide instrument according to claim 5, characterized in that the actuator (27) is at least indirectly, in particular directly and with a mating connection, connected to the feed tube (38).
7. 7. The medical guide instrument according to any one of claims 1 to 6, characterized in that the guide instrument (10) is self-supporting in the insertion position without the action of external forces.
8. 8. Medical guide instrument according to any one of the preceding claims, characterized in that the feed tube (38) is at least partially surrounded by a particularly rigid guide tube (36).
9. The guide instrument (10) has an inner bore (14, 21, 25) for receiving the electrode (20); The bore (14, 21, 25) extends over the entire, in particular axial, length of the guide instrument (10); A medical guide instrument according to any one of claims 1 to 8.
10. 10. The medical guide instrument of any one of claims 5 to 9, characterized in that the feed tube (38) is at least indirectly connected to the actuator (27) via a pull wire (70).
11. The medical guide instrument according to any one of the preceding claims, characterized in that the guide instrument (10) is designed as a disposable instrument.
12. 12. The medical guide instrument according to claim 1, wherein the first portion (41) of the feed tube (38) is arranged in an axial center portion (41a) of the feed tube (38).
13. 13. The medical guide instrument according to any one of claims 1 to 12, characterized in that the jacket (16) of the guide instrument (10) is provided with a flat portion (16a).
14. 14. The medical guide instrument according to any one of claims 1 to 13, characterized in that an adapter part (19) is provided having an inner bore (21) for accommodating the electrode (20), in particular the inner bore (21) of the adapter part (20) being radially enlarged towards a proximal end face (22) and / or towards a distal end face (23) of the adapter part (19).
15. A medical guide instrument (10) according to any one of claims 1 to 14, A medical electrode (20) having at least one conductive contact surface (65); A conductor (43) connected to the electrode (20); Medical instrument set with.
16. 16. The medical instrument set according to claim 15, characterized in that said conductor (43) has at least one flexible portion (48) and / or at least one rigid portion (47).
17. A medical guide instrument (10) according to any one of claims 1 to 14, in particular A medical device (49) comprising a medical instrument set according to claim 15 or 16 and a medical endoscope (50), The medical device comprises a guide instrument (10) capable of being housed within a working channel (51) of the endoscope (50).
18. A method for positioning a medical electrode (20) on the spinal nerve using a medical guide instrument (10) according to any one of claims 1 to 14, comprising the steps of: preparing access to the spinal nerve; introducing the medical guide instrument (10) into a delivery location to position the electrode (20) on the spinal nerve; actuating an insertion position of the medical guide instrument (10); inserting the medical electrode (20) through the delivery tube (38) of the medical guide instrument (10) until the electrode (10) is positioned over the nerve; The method according to claim 1,