DEVICE AND METHOD FOR PREVENTING AND TREATING A VASOSPASM

Abstract

The invention relates to a device having a stent structure (2) which is intended for insertion into intracranial blood vessels (6) of the human or animal body, wherein the stent structure (2) has an expanded state in which it is capable of abutting the inner wall of the blood vessel (6) and a compressed state in which it is movable through the blood vessel (6) when the stent structure (2) is inside a microcatheter (4), wherein the stent structure (2) is connected to an insertion aid (3) and wherein the stent structure (2) is capable of automatically transitioning into the expanded state upon release from the microcatheter (4), wherein the stent structure (2) has electrical conductors (13) via which electrical pulses, high-frequency pulses or ultrasonic pulses can be applied to nerve fibers extending in the vascular wall of the blood vessel (6) in order to temporarily or permanently reduce the function of the nerve fibers so as to allow prevention or treatment of vasospasm.

Claims

1. A device having a stent structure (2) which is intended for insertion into intracranial blood vessels (6) of the human or animal body, wherein the stent structure (2) has an expanded state in which it is capable of abutting the inner wall of the blood vessel (6) and a compressed state in which it is movable through the blood vessel (6) when the stent structure (2) is inside a microcatheter (4), wherein the stent structure (2) is connected to an insertion aid (3) and wherein the stent structure (2) is capable of automatically transitioning into the expanded state upon release from the microcatheter (4), characterized in that: the stent structure (2) has electrical conductors (13) via which electrical pulses, high-frequency pulses or ultrasonic pulses can be applied to nerve fibers extending in the vessel wall of the blood vessel (6) in order to temporarily or permanently reduce the function of the nerve fibers so as to allow prevention or treatment of vasospasm.

2. A device according to claim 1, characterized in that the stent structure (2) consists of individual, interconnected struts (7) or individual wires forming a mesh structure.

3. A device according to claim 2, characterized in that the stent structure (2) has a spine (9) which runs from proximal to distal and from which struts (7) originate which have electrical conductors (13) and, in the expanded state, form the circumference of the stent structure (2).

4. A device according to claim 2, characterized in that at least some struts (7) are composed of partial struts extending parallel to one another.

5. A device according to claim 1, characterized in that the electrical conductors (13) converge at the proximal end of the stent structure (2) and are connected to the insertion aid (3).

6. A device according to claim 1, characterized in that the electrical conductors (13) are electrically insulated from one another.

7. A device according to claim 1, characterized in that pairs of electrical or high frequency (HF) electrodes (8) connected to the electrical conductors (13) are arranged on the periphery of the stent structure (2) in such a manner that the electrodes (8) in the expanded state and implanted in the blood vessel (6) are spaced apart by a gap so that an applied current flow to the electrodes (8) across the gap acts on the inner wall of the blood vessel (6).

8. A device according to claim 7, characterized in that the electrodes (8) are provided with a radiographic marker (12).

9. A device according to claim 7, characterized in that the stent structure (2) is provided with several pairs of electrodes (8).

10. A device according to claim 7, characterized in that the gap between a pair of electrodes (8) is filled with an electrically insulating material.

11. A device according to claim 7, characterized in that the stent structure (2) comprises a plurality of substantially annular elements which are spaced in the longitudinal direction of the device (1), each element comprising two electrical conductors (13) that belong to an electric circuit, with the two electrical conductors (13) each terminating in one electrode (8) and the two electrodes (8) being separated from each other by a gap when the device (1) is implanted in the blood vessel (6) in the expanded state.

12. A device according to claim 1, characterized in that electrodes (8), pairs of electrodes (8) and/or ultrasonic transmitters, viewed in the longitudinal direction of the stent structure (2), are arranged offset relative to one another on the circumference.

13. A device according to claim 1, characterized by means for measuring electrical resistance.

14. A device according to claim 1, characterized in that the stent structure (2) is provided with a membrane (11) on the inside.

15. A method for the prevention or treatment of vasospasm, wherein the stent structure (2) of a device according to claim 1 is brought to the target position in a blood vessel (6) by means of the insertion aid and expanded, with electrical pulses, high-frequency pulses or ultrasonic pulses being applied at the target position to nerve fibers extending in the vascular wall of the blood vessel (6).

Description

[0046] Further elucidation of the invention is provided by way of example through the enclosed figures where

[0047] FIG. 1 is a side view of a device proposed by the invention;

[0048] FIG. 2 illustrates the stent structure of the inventive device shown in FIG. 1;

[0049] FIG. 3 is a partial view of the illustration shown in FIG. 2;

[0050] FIG. 4 shows an alternative stent structure;

[0051] FIG. 5 shows part of a stent structure having several electrical conductors;

[0052] FIG. 6 shows electrodes of the stent structure and

[0053] FIG. 7 illustrates a stent structure in developed form.

[0054] In FIG. 1 a device 1 according to the invention is shown in side view which is situated inside a blood vessel 6. Device 1 has a stent structure 2 and is provided with an insertion aid 3 in the form of a guidewire. The stent structure 2 is shown here in its expanded form implanted into the blood vessel 6. The stent structure 2 is advanced within the microcatheter 4 from proximal (here: left) to distal (here: right); by advancing the microcatheter 4 or withdrawing the stent structure 2, the structure folds up again so tightly that it can be accommodated in the microcatheter 4 for removal out of the blood vessel system together with the microcatheter. The microcatheter 4 itself is guided through another catheter 5 having a larger lumen.

[0055] The stent structure 2 is provided with struts 7, which are essentially ring-shaped in pairs and are intended to be placed in position against the inner wall of the blood vessel 6. In addition, the struts 7 are provided with electrical conductors which are electrically connected to the electrodes 8 located at the end of the struts 7. For each ring of struts 7 there are pairs of electrodes 8 that belong to each other, with a small gap being provided between them via which an impulse, for example an electrical or HF pulse, can be applied to the surrounding tissue. Furthermore, it can be seen that for the individual rings formed by the struts 7 the electrode pairs 8 and thus also the gap between the electrodes are offset from one another with respect to their position in the circumference of the blood vessel, that is, different rings of struts 7 apply pulses at different radial positions.

[0056] FIG. 2 is an enlarged view of the stent structure 2 depicted in FIG. 1. It can be seen that the struts 7 each in pairs form an open ring, with an electrode 8 being arranged at the end of each strut 7. For the individual rings of struts 7, which are arranged one behind the other in the longitudinal direction, the electrodes 8 are arranged offset from each other. The pulses, which are intended to act on different radial areas of the wall of the blood vessel and the nerve fibers running therein, can be emitted simultaneously, but said emission may also take place offset in time. For a certain ring of struts 7, the position where the pulse application is to take place may, for example, also be selected by appropriately displacing the stent structure 2 in longitudinal direction.

[0057] Struts 7 originate from a common spine 9 that runs in the longitudinal direction of stent structure 2. In the configuration shown here, the spine 9 itself can be divided in two so that one half of the spine 9 serves to supply power to the first half of the struts 7 while the second half of the spine 9 serves for supplying power to the second half of the struts 7.

[0058] A partial section of the stent structure 2 depicted in FIG. 2 is shown in FIG. 3; it can be seen how the struts 7 are connected to the spine 9 and that there is an insulation 10 between the two halves of the spine 9 which ensures that no short circuit occurs between the two halves of the spine 9.

[0059] FIG. 4 shows a stent structure 2 which is basically similar to the stent structure 2 illustrated in FIG. 2, but in which a membrane 11 is arranged on the luminal side, i.e. inside the stent structure 2, said membrane separating the actual lumen of the blood vessel 6 from the stent structure 2 and thus creates an isolation in the luminal direction.

[0060] In FIG. 5 two open rings are illustrated that are arranged one behind the other in the longitudinal direction and formed by struts 7, each originating from the spine 9. The latter is provided with 4 conductors A, B, C, D which ensure a current supply to the electrodes 8. The power supply via conductors A, B on the one hand and C, D on the other hand may take place simultaneously or sequentially.

[0061] FIG. 6 shows electrodes 8 forming the ends of the electrical conductors 13. In the embodiment shown here, the electrical power is conducted directly via the struts 7 to the electrodes 8, i.e. the struts 7 are also electrical conductors 13. To enable electrodes 8 to be visualized, they have an opening on the inside into which radiopaque markers 12 are pressed. The radiopaque markers 12, for example, can be made of platinum or a platinum alloy. In the radiographic image, the attending physician thus immediately recognizes how the electrodes 8 are arranged, which emit the pulses essential for the treatment. Moreover, the physician can verify that no short circuit has occurred between electrodes 8.

[0062] FIG. 7 depicts a stent structure 2 in developed form, that is, the struts 7 forming an open ring were pressed into a planar surface resulting in the two-dimensional representation shown. It can be seen that the struts 7 are of different lengths. In this manner it is achieved that after insertion into the blood vessel the electrodes 8 are finally arranged in an offset or staggered way on the inner wall of the blood vessel so that impulses are allowed to act on different sections/segments.