JP2016202556A - Nerve stimulation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nerve stimulation system capable of easy confirmation that a stationary part has been received into a withdrawal sheath.SOLUTION: A nerve stimulation system 1 comprises: a stationary part 10 formed from an elastic material, and when elastically deformed to be indwelt in a blood vessel, biasing inner surfaces of the blood vessel; at least a pair of electrode parts 20 arranged in the stationary part; a lead part 30 for electrical connection between a stimulation generator to generate electrical stimulation and at least the pair of electrode parts; and a withdrawal sheath which is formed cylindrically and through which the lead part is inserted advanceably and retractably, and into which the stationary part can be received when the stationary part is elastically deformed. The lead part comprises a withdrawal index part 41 which protrudes from the proximal part of the withdrawal sheath to a proximal side when the stationary part is received into the withdrawal sheath.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a nerve stimulation system that stimulates nerves transvascularly.

  Conventionally, research has been conducted on therapeutic methods by applying electrical stimulation to nerve tissue. As one of the nerve stimulation systems used for the treatment method, for example, the one described in Patent Document 1 is known.

The nerve stimulation system of Patent Document 1 includes a lead main body (lead portion) having a lead anchor (fixed portion) at a distal end portion. The lead anchor may be formed from one or more superelastic wires. Wires can be connected to form one or more cells. As the number of cells increases, the lead anchor may have a mesh shape. The lead anchor is configured to expand from a folded shape to an expanded shape.
The tip has one or more electrodes. When in the expanded configuration, the lead anchor presses the electrode against the vessel wall of the blood vessel. The lead body can be further rotated and aligned until a maximum or optimal electrical stimulation threshold with electrodes for the nerve to be stimulated across the vessel wall is achieved.

Special table 2010-516405 gazette

  The electrode placed in the blood vessel in this manner is pulled out (extracted) from the patient's blood vessel after applying electrical stimulation for a certain period of time. When the lead anchor has an expanded shape in the blood vessel, the expanded shape of the lead anchor may cause a burden on the blood vessel when the lead anchor is pulled out.

In view of this, an extraction sheath which is formed in a cylindrical shape and is housed inside in a state where the outer shape is reduced by elastically deforming the fixing portion has been studied. By doing so, the fixed part is pulled out from the blood vessel in a state in which the outer shape of the fixing part is reduced, so that it is difficult to apply a load to the blood vessel.
When the fixing portion is stored inside the extraction sheath, there is a problem that it is difficult to determine whether the fixing portion is stored inside the extraction sheath because the frictional force between the inner peripheral surface of the extraction sheath and the fixing portion is large. Performing the treatment of pulling out the fixed part under fluoroscopy increases the burden on the patient receiving X-rays.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a nerve stimulation system in which it can be easily understood that a fixing portion is housed in an extraction sheath.

In order to solve the above problems, the present invention proposes the following means.
The nerve stimulation system according to one aspect of the present invention includes a fixing unit that is formed of an elastic material and is elastically deformed and placed in the blood vessel to urge the inner surface of the blood vessel, and the fixing unit At least a pair of electrode portions, a stimulation generating device for generating electrical stimulation, and a lead portion for electrically connecting the at least a pair of electrode portions, and the lead portion can be moved forward and backward. An extraction sheath that can be housed in the state where the fixing portion is elastically deformed, and the lead portion has the extraction sheath when the fixing portion is accommodated in the inside of the extraction sheath. An extraction indicator portion protruding from the base end portion to the base end side is provided.

Further, in the above nerve stimulation system, the lead portion has a soft region that transmits only an elastic force of a size that does not move the fixing portion relative to the blood vessel even if it deforms, and is based on the soft region. A proximal end portion of the extraction sheath when a rigid region that transmits an elastic force large enough to move the fixing portion relative to the blood vessel and a soft region inserted into the blood vessel are slack on the end side It is more preferable that a sag indicator portion corresponding to the above is provided.
In the above nerve stimulation system, it is more preferable that a sag assist indicator part is provided on the distal end side or the proximal end side of the sag indicator part in the lead part.

  Further, in the above nerve stimulation system, at least one of the fixing portion and the distal end portion of the lead portion is provided with an engaging portion, which is formed in a cylindrical shape so that the lead portion is inserted so as to be able to advance and retract. An engagement sheath that can be engaged in the axial direction of the joint portion and the lead portion and around the axis is provided at the distal end portion. A soft region that transmits only an elastic force large enough not to move the fixing portion, and a hard region that transmits an elastic force large enough to move the fixing portion relative to the blood vessel, on the proximal side of the soft region. It is more preferable that an engagement indicator portion that protrudes from the proximal end portion of the operation sheath to the proximal end side when the engaging portion and the engaged portion are engaged is provided.

  Further, in the above nerve stimulation system, a removal assisting index portion having a different length in the axial direction of the lead portion from the removal index portion is provided on the proximal end side of the removal index portion in the lead portion. More preferably.

  According to the nerve stimulation system of the present invention, it can be easily understood that the fixing portion is accommodated in the extraction sheath.

1 is an overall view in which a part of a nerve stimulation system according to an embodiment of the present invention is broken. It is a principal part enlarged view in FIG. It is sectional drawing of the front of the state which the engaging part and engaged part of the same nerve stimulation system are engaging. It is a side view of the fixing | fixed part of the same nerve stimulation system, an electrode part, and a lead part. It is a side view of the extraction scale provided in the lead part, and an extraction auxiliary scale. It is a side view of the slack scale provided in the lead part. It is sectional drawing of the principal part of the operation sheath of the nerve stimulation system. It is sectional drawing of the principal part of the extraction sheath of the same nerve stimulation system. It is a figure which shows the example of the waveform which the pulse generator used with the nerve stimulation system generate | occur | produces. It is a flowchart which shows the indwelling method of the same nerve stimulation system. It is a figure which shows the state which inserted the fixing | fixed part in the superior vena cava explaining the procedure which indwells the nerve stimulation system. It is a figure which shows the positional relationship of the extraction sheath and slack indicator part explaining the procedure which indwells the same nerve stimulation system. It is a figure which shows an example in the state where the soft area | region of the lead part was sagging explaining the procedure which indwells the same nerve stimulation system. It is a figure which shows another example of the state which sagged the soft area | region of the lead part explaining the procedure which indwells the same nerve stimulation system. It is sectional drawing which shows the state which accommodated the fixing | fixed part inside the extraction sheath explaining the procedure which indwells the nerve stimulation system. It is a perspective view of the fixing | fixed part in the modification of the nerve stimulation system of embodiment of this invention. It is a perspective view of the fixing | fixed part in the modification of the nerve stimulation system of embodiment of this invention. It is a perspective view of the fixing | fixed part in the modification of the nerve stimulation system of embodiment of this invention. It is a perspective view of the fixing | fixed part in the modification of the nerve stimulation system of embodiment of this invention.

Hereinafter, an embodiment of a nerve stimulation system (hereinafter also abbreviated as “system”) according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the nerve stimulation system 1 according to the present embodiment generates electrical stimulation with a fixed portion 10 made of an elastic material, a pair of electrode portions 20 provided on the fixed portion 10, and the like. A lead portion 30 that electrically connects the pulse generator (stimulation generating device) 200 and the pair of electrode portions 20, and an operation sheath 55 and a removal sheath 70 that are formed in a cylindrical shape and are inserted through the lead portion 30 so as to be able to advance and retract. It has.
In all the drawings below, the thicknesses and dimensions of the components are adjusted to make the drawings easy to see.
The fixed portion 10 side with respect to the lead portion 30 is referred to as a distal end side, and the lead portion 30 side with respect to the fixed portion 10 is referred to as a proximal end side.

The fixing portion 10 has a plurality of urging portions 11 which are formed in a linear shape and connected to each other's distal ends and to which their proximal ends are connected. Each urging portion 11 includes a wire (not shown) and an insulating coating 12 that covers the periphery of the wire. Each wire is formed of a shape memory alloy or a super elastic wire made of a biocompatible material. As the material for forming the wire, a material that exhibits a restoring force to return the wire to its original shape when the external force is removed after the wire is deformed by applying an external force is used. The outer diameter of the wire is set to about 0.2 to 0.5 mm, for example, and the cross-sectional shape orthogonal to the longitudinal direction of the wire is circular, elliptical, rectangular or the like.
By applying the coating 12 around the wire, the smoothness of the outer peripheral surface of the wire can be improved, and a thrombus reduction effect and insulation can be imparted to the wire. For the coating 12, for example, a polyurethane resin, a polyamide resin, a fluororesin, or the like can be used. The thickness of the film 12 is, for example, 50 to 500 μm (micrometer). Note that the coating 12 may not be provided on the wire.

The urging portions 11 are spaced apart from each other around the axis C of the lead portion 30 and are arranged around the axis C at equal angles (for example, every 90 ° if the number of urging portions 11 is four). Yes. An intermediate portion of each urging portion 11 in the direction of the axis C is curved so as to be convex in a direction away from the axis C, and the fixed portion 10 including the plurality of urging portions 11 is substantially spherical as a whole. It becomes.
The outer diameter of the fixed portion 10 in a natural state where no external force other than gravity is applied is about φ20 to 40 mm, which is larger than the inner diameter of the superior vena cava.

As shown in FIG. 2, when the fixing portion 10 configured in this way is inserted into a blood vessel such as the superior vena cava P1, the urging portion 11 is imaginary line L ₁ by the blood vessel wall P2 of the superior vena cava P1. By elastically deforming as shown by, it is compressed (deformed) elastically so as to approach the axis C. As a reaction force against the compressive force of the blood vessel wall P2, the fixing portion 10 generates an elastic force generated by elastic deformation with respect to the blood vessel wall P2, that is, a pressing force that urges the inner surface of the superior vena cava P1 radially outward. For this reason, the fixing part 10 biases the inner surface of the superior vena cava P1.
The fixing portion 10 is fixed at a desired position in the superior vena cava P1 by the frictional force between the blood vessel wall P2 generated by the pressing force and the urging portion 11 of the fixing portion 10. The fixing portion 10 extends when compressed so as to approach the axis C as shown in phantom L ₁ in the axial direction C.
When the urging portions 11 are arranged around the axis C at equal angles, good operability of the fixed portion 10 can be obtained. However, it is not necessary to arrange each urging portion 11 around the axis C at every equal angle, for example, for fitting with a specific anatomy.

One of the plurality of urging portions 11 is provided with the pair of electrode portions 20 described above. Note that the pair of electrode portions 20 described above may be provided in different biasing portions 11.
Each electrode unit 20 is disposed between the wire and the coating 12. The electrode unit 20 is formed of platinum, a platinum iridium alloy, or the like.
An insulating partition film (not shown) exists between the electrode portion 20 and the wire, and the wire and the electrode portion 20 are electrically insulated. The electrode portion 20 is formed, for example, in a ring shape on the partition coating, and is formed by removing and exposing a part of the coating 12 covering the electrode portion 20. That is, as described later, when the fixing portion 10 is placed in the blood vessel, the electrode portion 20 is exposed in the blood vessel.
At this time, it is possible to give directionality to the position where the electrode part 20 is provided, for example, the urging part 11 is formed so that the electrode part 20 is exposed on the side opposite to the axis C. The exposed area of the electrode part 20 is about 1-5 mm < ² >, for example. The pair of electrode portions 20 are arranged along the longitudinal direction of the urging portion 11 with an interval of, for example, about 3 to 20 mm.

Each electrode portion 20 is electrically connected to the tip end portion of the electrical wiring 14 shown in FIG. As the electrical wiring 14, a stranded wire made of a nickel cobalt chrome alloy (35NLT 25% Ag material, 35NLT 28% Ag material, or 35NLT 41% Ag material) having bending resistance is used as an electrical insulating material (for example, ETFE (thickness 20 μm)). Those coated with tetrafluoroethylene-ethylene copolymer resin) or PTFE (tetrafluoroethylene resin) can be suitably used.
As will be described later, the electric wiring 14 extends through the pipe 31 of the lead portion 30 to the proximal end side.

The lead part 30 is formed of a biocompatible material (for example, polyurethane resin or polyamide resin) or the like, and as shown in FIG. 3, a pipe line 31 and a housing part 32 are formed. The pipe line 31 penetrates the lead part 30 in the axis C direction. An electric wiring 14 having a conductor is inserted into the conduit 31.
Further, a stainless wire, for example, may be inserted into the conduit 31 as a tension member. With this configuration, the tensile strength of the lead portion 30 can be increased.
The distal end of the housing portion 32 is closed, and a known stylet D can be inserted. In order to improve the slidability with the stylet D, a film such as ETFE resin or PTFE resin may be formed on the inner surface of the accommodating portion 32.
By inserting the stylet D into the housing part 32, the rigidity of the lead part 30 can be increased.

As shown in FIG. 4, the lead portion 30 includes a distal end portion 33 attached to the fixing portion 10, a soft region 34 provided on the proximal end side with respect to the distal end portion 33, and a proximal end side with respect to the soft region 34. And a hard region 35 provided.
The tip 33, the hard region 35 and the soft region 34 have different hardness, and the tip 33 and the hard region 35 are harder than the soft region 34. In other words, the soft region 34 has a sufficiently soft first bendability, and the tip 33 and the hard region 35 have a pushability hardness and a second bendability that is harder than the first bendability. doing.
The distal end portion 33 and the rigid region 35 are hardnesses that transmit an elastic force large enough to move the fixing portion 10 against a blood vessel such as the superior vena cava P1 against the frictional force described above. Note that the movement of the fixing unit 10 relative to the blood vessel here means both movement along the longitudinal direction of the blood vessel and movement (rotation) around the longitudinal direction of the blood vessel.
On the other hand, the soft region 34 is a region that is sufficiently soft and transmits only an elastic force that does not move the fixing unit 10 relative to the blood vessel even if it deforms.

Specifically, in accordance with JIS K7215, the Shore hardness measured by using a type D durometer (hereinafter abbreviated as “Shore hardness (D)”) is a push-in operation (push operation) at the tip 33 and the rigid region 35. And 50 or more, and more preferably 55 or more and 70 or less having sufficient hardness for the rotation operation.
The shore hardness (D) of the soft region 34 is 20 or more and 40 or less, and is sufficiently soft. The Shore hardness (D) of the soft region 34 is more preferably 30 or less.
The tip 33, the hard region 35, and the soft region 34 have different hardnesses, for example, by changing the type of polyurethane resin.
For joining the tip portion 33 and the soft region 34 and between the soft region 34 and the hard region 35, adhesion by a known adhesive, thermal welding, ultrasonic welding, or the like can be appropriately selected and used.
The dimensions of the lead part 30 are, for example, an outer diameter of about 0.8 to 2 mm and a length of about 500 to 1000 mm.

  As shown in FIGS. 1 and 3, the leading end portion 33 is formed with a lead-side protruding portion 38 that protrudes radially outward from the outer peripheral surface. The lead-side protrusion 38 is formed in an arc shape when viewed in the direction of the axis C shown in FIG. In this example, four lead side protrusions 38 are arranged around the axis C so as to be separated from each other at equal angles. The lead side protrusion 38 is made of the same material as the tip portion 33 and is formed integrally with the tip portion 33. In addition, you may form the front-end | tip part 33 and the lead side protrusion 38 with metal materials which have biocompatibility, such as titanium and stainless steel.

  As shown in FIG. 1, the four lead-side protrusions 38 and the base end portions 11 a of the plurality of biasing portions 11 constitute an engaging portion 39. That is, in the present embodiment, the engaging portion 39 is provided on both the tip portion 33 and the fixing portion 10 of the lead portion 30.

The length of the flexible region 34 (the length in the direction of the axis C) is a length sufficient to absorb external force due to body movement or the like. For example, when the nerve stimulation system 1 is implanted from the internal jugular vein, about 50 to 200 mm, and when it is implanted from the subclavian vein, the suitable length varies depending on the insertion position.
It has been confirmed that the soft region 34 can sufficiently absorb external force in a length of about 100 to 150 mm.

As shown in FIGS. 4 and 5, in this embodiment, an extraction scale (extraction index portion) 41 and extraction auxiliary scales (extraction auxiliary index portions) 42 and 43 are provided on the outer peripheral surface of the soft region 34. The method for forming the scales 41, 42, 43 in the soft region 34 is not particularly limited, and a method of printing with a known ink, a method of baking the soft region 34 with a laser beam, or the like can be appropriately selected and used. Tubular members of different colors may be joined by welding or the like, and the portion where the two members are connected may change the color.
Alternatively, a convex shape may be provided on the outer peripheral surface by welding a part to the outer peripheral surface of the soft region 34, and the convex shape may be used as a scale. A concave shape may be formed by contracting a part of the outer peripheral surface of the flexible region 34, and the concave shape may be used as a scale.

The length from the distal end of the lead portion 30 to withdrawn the scale 41 L ₃ will be described later. In the soft region 34, an extraction auxiliary scale 42 is provided on the base end side with respect to the extraction scale 41, and an extraction auxiliary scale 43 is provided on the base end side of the extraction auxiliary scale 42.
The lengths of the scales 41, 42, 43 in the direction of the axis C are different from each other. Specifically, the extraction auxiliary scale 42 is shorter than the extraction scale 41, and the extraction auxiliary scale 43 is shorter than the extraction auxiliary scale 42. That is, the scales 41, 42, and 43 have a shorter length in the direction of the axis C as they are closer to the base end.
The distance between the extraction scale 41 and the extraction auxiliary scale 42 and the distance between the extraction auxiliary scale 42 and the extraction auxiliary scale 43 are, for example, 5 mm.

As shown in FIGS. 4 and 6, a slack scale set 45 and an engagement scale (engagement index portion) 46 are provided on the outer peripheral surface of the hard region 35.
In the present embodiment, the sag scale set 45 includes a main scale (slack index part) 45a and a plurality of auxiliary scales (slack auxiliary index part) 45b formed so as to sandwich the main scale 45a in the axis C direction. ing. In this example, a pair of second auxiliary scales (slack auxiliary indicator portions) 45c are provided so as to sandwich the main scale 45a and the plurality of auxiliary scales 45b in the direction of the axis C.

The length _{L 4} from the distal end of the lead portion 30 to the axis line C direction of the center of the main scale 45a is, for example, 300 mm. By making the auxiliary scale 45b shorter than the main scale 45a in the length in the axis C direction, the main scale 45a and the auxiliary scale 45b can be easily distinguished. The length of the second auxiliary scale 45c in the direction of the axis C is substantially equal to the length of the main scale 45a in the direction of the axis C.
The plurality of auxiliary scales 45b and 45c are formed on the distal end side and the proximal end side of the main scale 45a, for example, over a length of about 50 mm at a pitch of 10 mm.

As shown in FIG. 4, the engagement scale 46 is provided on the base end side with respect to the slack scale set 45. The length from the distal end of the lead portion 30 to engage the scale 46 L ₅ will be described later.
The slack scale set 45 and the engagement scale 46 can be formed in the same manner as the scales 41, 42, and 43.

A connector 48 for connecting to the pulse generator 200 is attached to the proximal end portion of the rigid region 35. As the connector 48, for example, a known IS-1 connector, other waterproof connectors, or the like can be used. As shown in FIG. 3, the aforementioned electrical wiring 14 is inserted into the conduit 31 of the lead portion 30, and the proximal end portion of the electrical wiring 14 is connected to the connector 48.
The rigid region 35 may not include the connector 48, and the proximal end portion of the rigid region 35 may be fixed to the pulse generator 200.

As shown in FIGS. 1 and 7, the operation sheath 55 has a sheath body 56 and a hub 57 fixed to the proximal end portion of the sheath body 56.
The sheath body 56 is formed of a biocompatible material such as polyurethane resin, polyamide resin, polyethylene resin, or fluororesin.
As shown in FIGS. 1 and 3, an engaged portion 59 that can be engaged with the lead-side protruding portion 38 of the engaging portion 39 is provided on the inner peripheral surface of the distal end portion of the sheath body 56. The engaged portion 59 has four sheath-side protrusions 60 that protrude radially inward from the inner peripheral surface of the sheath body 56.
The sheath side protrusion 60 is formed in a trapezoidal shape when viewed in the direction of the axis C shown in FIG. The four sheath-side protrusions 60 are arranged around the axis C so as to be separated from each other at equal angles.

The engaged portion 59 may be formed integrally with the sheath body 56, that is, the sheath body 56 may be deformed. The engaged portion 59 configured as a part different from the sheath body 56 in advance may be attached to the sheath body 56.
The shore hardness (D) of the sheath body 56 and the sheath side protrusion 60 is equal to the shore hardness (D) of the rigid region 35 of the lead portion 30 (the shore hardness (D) is about 55 or more and 70 or less).
A metal blade using stainless steel or tungsten may be enclosed in the resin forming the sheath body 56 to improve the rigidity and kink resistance of the sheath body 56. In addition, the antithrombogenicity and slidability may be improved by applying an arbitrary film to the surface of the sheath body 56.

  When the sheath side protrusion 60 is disposed between the lead side protrusions 38 adjacent to each other around the axis C, the sheath side protrusion 60 engages around the axis C with respect to the lead side protrusion 38. Further, at this time, the distal end surface of the sheath side protrusion 60 abuts on the base end portion 11a of the urging portion 11 so that the fixing portion 10 and the sheath side protrusion 60 are engaged in the axis C direction.

As shown in FIG. 7, the hub 57 is formed in a cylindrical shape, and a stepped portion 57 a is formed at the tip of the outer peripheral surface of the hub 57 by reducing the outer diameter. A stepped portion 57 a of the hub 57 is attached to the proximal end portion of the sheath body 56.
An O-ring 58 is disposed in a groove 57 b formed on the inner peripheral surface of the hub 57. The hub 57 is formed with a side hole 57c that communicates with the cylindrical hole in the radial direction and opens to the base end side.
The hub 57 is formed of a biocompatible material such as polycarbonate or ABS (acrylonitrile / butadiene / styrene resin).

The lead part 30 can be inserted into the O-ring 58. The lead part 30 can slide in the direction of the axis C while sliding with respect to the O-ring 58, and the space between the O-ring 58 and the lead part 30 is sealed in a watertight manner. This prevents blood backflow.
One end of a tube 63 is connected to the side hole 57c, and a general connector 64 (see FIG. 1) such as a luer lock connector is provided at the other end of the tube 63. A medical solution such as heparinized physiological saline can be supplied into the operation sheath 55 through the tube 63 from a syringe pump (not shown) attached to the connector 64.
Note that the tube 63 is not essential, and a connector or the like to which a commercially available medication tube or the like can be connected may be provided directly in the side hole 57c.

The overall dimensions of the operation sheath 55 are, for example, an outer diameter of about 2.0 to 2.9 mm, an inner diameter of about 1.0 to 2.5 mm, and a length of about 300 to 400 mm.
It is more preferable that the operation sheath 55 is made of a resin that can be peeled away so that it can be removed from the lead portion 30 as will be described later, and can be removed by tearing by hand. As the resin that can be peeled away, for example, a resin in which the orientation of the resin is controlled and torn, or a resin in which a groove serving as a cut line is provided on the outer periphery of the sheath can be used.
When removing the operation sheath 55, it may be removed using a surgical tool such as scissors without tearing by hand.

By moving the lead portion 30 to the proximal end side with respect to the operation sheath 55 (retracting or retreating), the engaged portion 59 of the operation sheath 55 is engaged with the engaging portion 39 of the fixed portion 10 and the lead portion 30. To do. At this time, as shown in FIG. 7, a part of the engagement scale 46 protrudes from the proximal end portion of the operation sheath 55 to the proximal end side. Accordingly, the length _{L 5} from the distal end of the lead portion 30 to engage the scale 46 is, for example, about 300～410Mm.
Note that when the engaged portion 59 is engaged with the engaging portion 39, the entire engagement scale 46 may protrude from the proximal end portion of the operation sheath 55 to the proximal end side.

As illustrated in FIG. 1, the extraction sheath 70 is disposed on the proximal end side with respect to the operation sheath 55.
The configuration of the extraction sheath 70 is substantially the same as that of the operation sheath 55. As shown in FIGS. 1 and 8, the extraction sheath 70 includes a cylindrical sheath body 71 and a hub 72 fixed to the proximal end portion of the sheath body 71. The sheath main body 71 and the hub 72 can be formed of the same material as the sheath main body 56 and the hub 57 of the operation sheath 55, respectively.

As will be described later, since the fixing portion 10 is accommodated in the extraction sheath 70 when the nerve stimulation system 1 is extracted, the inner diameter of the sheath body 71 is preferably equal to or greater than the inner diameter of the lead portion 30.
In addition, since the extraction sheath 70 is held in a state where at least a part thereof is out of the body when the nerve stimulation system 1 is indwelled, the length of the sheath main body 71 is preferably 100 mm or less, and the fixing portion 10 is completely From the viewpoint of storing in the container, about 50 to 100 mm is more preferable. The rigidity of the sheath main body 71 is such that the sheath main body 71 is not compressed and deformed in the direction of the axis C when the fixing portion 10 is stored, and the fixing portion 10 can be stored well (for example, about 55 to 70 in terms of Shore hardness (D)). Set to

A metal blade using stainless steel or tungsten may be enclosed inside the resin forming the sheath body 71 to improve the rigidity and kink resistance of the sheath body 71. In addition, the antithrombogenicity and slidability may be improved by applying an arbitrary film to the surface of the sheath body 71.
The dimensions of the sheath body 71 are, for example, an outer diameter of about 2.5 to 2.9 mm, an inner diameter of about 2.0 to 2.5 mm, and a length of about 50 to 100 mm.

The hub 72 is formed in a cylindrical shape, and a stepped portion 72 a is formed at the distal end portion of the outer peripheral surface of the hub 72 by reducing the outer diameter. A stepped portion 72 a of the hub 72 is attached to the proximal end portion of the sheath body 71.
The proximal end portion of the inner peripheral surface of the hub 72 has an enlarged diameter portion 72b formed by increasing the inner diameter. An O-ring 73 is disposed at the tip of the enlarged diameter portion 72b. A female screw portion 72c is formed on the inner peripheral surface of the enlarged diameter portion 72b on the proximal end side with respect to the O-ring 73. A thread hooking groove 72d is formed in the circumferential direction at the base end of the outer peripheral surface of the hub 72.
The hub 72 is formed with a side hole 72e communicating with the cylindrical hole from the radial direction.

The hub 72 is provided with a wing portion 74 which is formed in a flat plate shape and has a thread hooking hole 74a.
The wing 74 is used to fix the extraction sheath 70 to the body surface by passing the thread that has passed through the patient's skin through the thread hooking hole 74a. The thread passed through the skin may be wound around the thread hooking groove 72d of the hub 72 as necessary. By fixing the flat wing 74 to the patient's skin with a tape or the like, the extraction sheath 70 is prevented from rotating around the axis C during the treatment period of the electrode unit 20.

A male screw portion 76 a formed on the outer peripheral surface of the tightening knob 76 is screwed into the female screw portion 72 c of the hub 72. The lead portion 30 can be inserted into the tightening knob 76 and the O-ring 73 described above.
When the male screw portion 76a is moved (tightened) to the distal end side with respect to the female screw portion 72c, the O-ring 73 is compressed in the direction of the axis C, so that the inner diameter of the O-ring 73 is reduced. By adjusting the length at which the tightening knob 76 is tightened, the lead portion 30 is slidable with respect to the extraction sheath 70 while being slidable, or the lead portion 30 is fixed to the extraction sheath 70. Or can be in a fixed state.

One end of a tube 77 is connected to the side hole 72 e of the hub 72. As shown in FIG. 1, a connector 78 similar to the connector 64 described above is provided at the other end of the tube 77.
A medical solution such as heparinized physiological saline can be supplied into the extraction sheath 70 via the tube 77 from a syringe pump (not shown) attached to the connector 78.
Note that the tube 77 is not essential, and a connector or the like to which a commercially available medication tube or the like can be connected may be provided directly in the side hole 72e.

As will be described later, the fixing portion 10 is inserted into the blood vessel through an opening formed in the patient, and the lead portion 30 is pushed (moved toward the distal end side) to sag the soft region 34. When the soft region 34 inserted into the blood vessel is slack, the center in the axis C direction of the main scale 45a of the slack scale set 45 coincides with the proximal end portion of the extraction sheath 70.
The center of the main scale 45a in the direction of the axis C is matched with the base end of the extraction sheath 70, but it may be the tip or the base end of the main scale 45a in the direction of the axis C.

Inside the sheath main body 71 of the extraction sheath 70, as shown in FIG. 8, the fixing | fixed part 10 of the state which elastically deformed each urging | biasing part 11 can be accommodated. The urging portion 11 moves to the proximal end side with respect to the sheath body 71 while generating a frictional force with the inner peripheral surface of the sheath body 71. The fixing portion 10 moves to the proximal end side until the proximal end portion 11 a of the urging portion 11 contacts the distal end surface of the hub 72.
When the proximal end portion 11 a of the urging portion 11 comes into contact with the distal end surface of the hub 72, the fixing portion 10 is stored inside the extraction sheath 70. The lead portion 30 is pulled back with respect to the extraction sheath 70 and the fixing portion 10 is accommodated. At this time, as shown in FIG. 5, the entire extraction scale 41 protrudes from the proximal end portion of the extraction sheath 70 to the proximal end side. . When the length from the distal end portion of the hub 72 to the proximal end portion is 40 mm, for example, the length L ₃ from the distal end of the lead portion 30 to the removal scale 41 is about 45 mm.
When the extraction scale 41 protrudes from the extraction sheath 70 to the proximal end side, the extraction auxiliary scales 42 and 43 also protrude from the proximal end portion of the extraction sheath 70 to the proximal end side.

The pulse generator 200 has an electrical stimulation supply unit (not shown) and can generate electrical stimulation by a constant current method or a constant voltage method. In this example, as shown in FIG. 9, as electrical stimulation, a biphasic waveform group that is a constant current method and whose phase is switched is generated with a predetermined interval. Specific waveforms include, for example, a frequency of 10 to 20 Hz (hertz), a pulse width of 50 to 400 ms (milliseconds), and a positive maximum current of 0.25 to 15 mA (ampere) to a negative maximum current of −0.25 to − The thing whose electric current changes between 15 mA can be mentioned.
The pulse generator 200 applies such a biphasic waveform for an arbitrary number of seconds per minute. For example, when it is desired to apply the voltage intensively for 3 to 10 seconds, the time is 60 seconds.

As described above, the pulse generator 200 is connected to the lead portion 30 via the connector 48. The connector 48 may be detachable from the pulse generator 200 or may be fixed to the pulse generator 200.
When the pulse generator 200 and the lead unit 30 are connected, the electrical stimulation generated by the electrical stimulation supply unit is applied between the pair of electrode units 20 provided in the fixed unit 10 via the electrical wiring 14. . At that time, one of the paired electrode portions 20 acts as a plus electrode, and the other acts as a minus electrode.

  Next, a treatment (procedure) for placing the fixed portion 10 of the nerve stimulation system 1 configured as described above in the superior vena cava P1 will be described. FIG. 10 is a flowchart showing the indwelling method of the nerve stimulation system 1. Note that the nerve stimulation system 1 is suitable for short-term nerve stimulation of, for example, several days, unlike the long-term nerve stimulation system in which the entire system is implanted in the patient's body.

First, the surgeon connects the connector 48 of the lead part 30 to the pulse generator 200.
In the engagement step (step S1 in FIG. 10), the operation sheath 55 is moved to the distal end side with respect to the lead portion 30 outside the patient's body, and the engagement scale is moved from the proximal end portion of the operation sheath 55 as shown in FIG. A part of 46 protrudes to the base end side. Thereby, the engaging part 39 of the fixing part 10 and the lead part 30 and the engaged part 59 of the operation sheath 55 are engaged.
The operation sheath 55 and the extraction sheath 70 are filled with heparinized physiological saline or the like, and the air is extracted. An electrocardiograph for measuring heart rate is attached to the patient.

As shown in FIG. 11, a small incision is made near the neck of the patient P to form an opening P4. A known introducer (insertion tool) 205 is attached to the opening P4. The tip of the introducer 205 is inserted into the internal jugular vein (blood vessel) P5. At this time, it is desirable to install the introducer 205 so that the tip of the introducer 205 reaches the superior vena cava P1. By doing so, a valve or the like in the blood vessel can be avoided at the time of inserting the fixing portion 10 to be described later, so that operability and safety are improved.
The following description will be made using the internal jugular vein P5. However, in this procedure, the external jugular vein may be used instead of the internal jugular vein P5.

Next, in the fixing portion insertion step (step S3), the fixing portion 10 is inserted into the blood vessel through the introducer 205. At this time, the fixing portion 10 is inserted after being elastically deformed (reduced diameter) to an outer diameter that can be inserted into the introducer. At the time of insertion, the positions of the electrode unit 20, the wire, and the electrical wiring 14 of the nerve stimulation system 1 are confirmed under fluoroscopy.
When the operator grasps and pushes the proximal end side of the operation sheath 55 or rotates it around the axis C, the applied force is a relatively hard operation sheath 55, engaged portion 59, engaging portion 39, Then, it is transmitted to the fixing portion 10 via the tip portion 33 of the lead portion 30.
When the operation sheath 55 is pushed in, the fixing portion 10 protrudes from the introducer 205 toward the distal end, and the fixing portion 10 is introduced into the blood vessel. When the fixing portion 10 is introduced into the blood vessel, as shown in FIG. 2, each urging portion 11 is elastically deformed in the direction of the axis C by being pushed by the blood vessel wall P2, and the diameter of the fixing portion 10 is reduced as a whole. And extends in the direction of the axis C. Thereby, the outer diameter of the fixing | fixed part 10 becomes smaller than the outer diameter in a natural state.

The surgeon pushes the operating sheath 55 under X-ray fluoroscopy and roughly installs the fixing portion 10 in the superior vena cava P1 as shown in FIG.
When the introducer 205 is installed so that the distal end portion of the introducer 205 is positioned in the superior vena cava P1, the fixed portion 10 can be introduced into the superior vena cava P1 simply by projecting the fixed portion 10 from the introducer 205. . Also at this time, since the outer diameter of the fixed portion 10 is set as described above, each urging portion 11 is pressed against the axis C side by the superior vena cava P1. A pair of electrode portions 20 provided on the fixing portion 10 are arranged so as to contact the blood vessel wall P2 of the superior vena cava P1.
As shown in FIG. 11, the vagus nerve P6 to be stimulated is running parallel to the superior vena cava P1.

Next, in the position and orientation adjustment step (step S5), while applying electrical stimulation between the pair of electrode parts 20, the electrode part 20 in the superior vena cava P1 is lowered so that the heart rate of the patient P decreases. Adjust position and orientation. Specifically, the surgeon operates the pulse generator 200 to apply electrical stimulation between the pair of electrode portions 20. This means that an electrical stimulus is applied to the patient P who is a living body.
In this state, the operator operates the proximal end side of the operation sheath 55 to push in the operation sheath 55, or grasps the lead portion 30 and pulls back the lead portion 30 to fix the fixed portion 10 in the superior vena cava P1. That is, the position of the electrode portion 20 in the axis C direction is adjusted. Further, the operation sheath 55 is rotated around the axis C to adjust the circumferential direction of the fixed portion 10. While adjusting the position and orientation, the heart rate of the patient P is measured by an electrocardiograph. When the electrode unit 20 is arranged so as to approach and face the vagus nerve P6, and the electrical stimulation applied from the electrode unit 20 to the vagus nerve P6 increases, the heart rate of the patient P decreases most.
The surgeon adjusts the position and orientation of the fixing unit 10, that is, the electrode unit 20 so that the heart rate is the lowest, that is, the electrode unit 20 faces the vagus nerve P6 side.

When the position and orientation of the electrode unit 20 are determined, the nerve stimulation system 1 is placed. In the series of indwelling operations described below, care is taken not to cause displacement of the electrode unit 20.
First, the operator pulls back only the operation sheath 55 while holding the lead portion 30 and retracts, thereby releasing the engagement between the engaging portion 39 and the engaged portion 59. At this time, if the operation of pushing in the lead part 30 is interwoven, the soft region 34 is slightly slackened, so that the displacement of the electrode part 20 in the superior vena cava P1 can be prevented.

When the position of the electrode portion 20 is shifted, the engaged portion 59 of the operation sheath 55 is engaged with the engaging portion 39 of the fixing portion 10 and the lead portion 30 to readjust the position and orientation of the electrode portion 20. I do.
Here, in order to engage the engaging portion 39 and the engaged portion 59 in the patient's body, more specifically, in the blood vessel, the engaging operation is performed using the engaging scale 46 provided in the lead portion 30 as a guide. Specifically, the engagement scale 46 is projected from the proximal end portion of the operation sheath 55 to the proximal end side.
The operation for adjusting the position and orientation of the electrode unit 20 performed thereafter is as described above.
When it is confirmed that there is no displacement, the operation sheath 55 is pulled out from the blood vessel and peeled away to remove the operation sheath 55.

Next, in the extraction sheath insertion step (step S7), the introducer 205 is removed by peel away or the like.
Subsequently, the distal end side of the extraction sheath 70 is inserted into the blood vessel through the opening P4. Specifically, the tightening knob 76 of the extraction sheath 70 is loosened to make it slidable. As shown in FIG. 12, the extraction sheath 70 is pushed into the lead portion 30 to insert the distal end side of the extraction sheath 70 into the blood vessel.
It is more preferable to remove the introducer 205 and insert the extraction sheath 70 at the same time. First, the extraction sheath 70 is inserted into the proximal end portion of the introducer 205. Next, the removal sheath 70 is advanced in the introducer 205 while peeling away the introducer 205 and the like. In this way, when the introducer 205 is completely removed, the distal end of the removal sheath 70 can be inserted into the blood vessel through the opening P4. Thereby, the risk of blood vessel damage and the amount of bleeding during the procedure can be reduced.

Next, in the sag forming step (step S <b> 9), the lead portion 30 is moved to the distal end side with respect to the removal sheath 70, and the center of the main scale 45 a of the sag scale set 45 is aligned with the proximal end portion of the removal sheath 70.
By pushing the lead portion 30 and feeding it into the blood vessel, the lead portion 30 located in the blood vessel has a certain margin, and the soft region 34 of the lead portion 30 is slackened. From the tip of the lead 30 to the axial direction C of the center of the main scale 45a the length L _4, for example by a 300 mm, creating a standard slack amount.

As shown in FIG. 13, the soft region 34 of the lead part 30 may be slackened in the blood vessel. As shown in FIG. 14, the sag of the soft region 34 of the lead portion 30 in the blood vessel may be increased, and the soft region 34 may be formed in a loop shape.
The shape that sags the soft region 34 may be a regular shape such as a spiral shape, or may be an irregular shape. In order to absorb external force, it is preferable that the flexible region 34 is slackened by, for example, 50 mm or more.
The tightening knob 76 of the extraction sheath 70 is tightened to a fixed state. Thereafter, the hub 72 is fixed to the skin of the neck P8 by threading or taping.

For example, according to the physique of the patient P, the scale of the slack scale set 45 matched with the proximal end portion of the extraction sheath 70 may be changed.
For example, when the patient P is small, instead of the center of the main scale 45a, the center of the auxiliary scale 45b or the second auxiliary scale 45c provided on the tip side of the main scale 45a is made to coincide with the opening P4. By doing so, the amount of insertion of the lead portion 30 into the blood vessel is reduced, and the flexible region 34 sags in accordance with the physique of the patient P.
As described above, the amount of sag can be arbitrarily adjusted based on the main scale 45a and the auxiliary scales 45b and 45c according to the judgment of the surgeon.

Through the above steps, the fixing unit 10 provided with the electrode unit 20 is placed in the superior vena cava P1.
Thereafter, in the indwelling step (step S11), nerve stimulation treatment of the vagus nerve P6 that is indwelled while applying electrical stimulation between the pair of electrode portions 20 for a certain period is performed. If necessary, a syringe pump or the like can be connected to the connector 78 of the extraction sheath 70 to administer a liquid such as heparinized physiological saline.

If the electrical stimulation is continuously applied to the vagus nerve P6 for a certain period using the nerve stimulation system 1, the electrical stimulation is stopped by operating the pulse generator 200 and the system 1 is started to be removed. Surgical reoperation is not required for removal of the system 1.
First, the fixation of the skin of the neck P8 and the hub 72 is released by cutting a thread or the like. Next, the tightening knob 76 of the extraction sheath 70 is loosened to make it slidable.

Next, in the fixing portion storing step (step S13), as shown in FIG. 15, the lead portion 30 is pulled back toward the proximal end side with respect to the removal sheath 70, and the entire removal scale 41 is formed from the proximal end portion of the removal sheath 70. Project to the end side. Note that the step of releasing the fixation between the skin of the neck P8 and the hub 72 by cutting the above-described thread or the like may be performed at this time, not at the beginning (sagging step S9).
Specifically, the operator grasps the lead portion 30 and pulls it back while holding the hub 72 of the removal sheath 70 so that the removal sheath 70 does not come out of the blood vessel.
Before the extraction scale 41 protrudes from the extraction sheath 70, the extraction auxiliary scale 43 and the extraction auxiliary scale 42 sequentially protrude from the extraction sheath 70 toward the proximal end side. As a result, the surgeon knows that the removal scale 41 is projected from the removal sheath 70 soon. By using the extraction auxiliary scales 42 and 43, it is possible to inform the operator of the standard for storing the fixing portion 10 inside the extraction sheath 70. The scales 41, 42, 43 are shorter in length toward the proximal end side, so that it is possible to visually tell the operator that the storage of the fixing portion 10 is almost completed.

  By projecting the entire extraction scale 41 from the extraction sheath 70 to the proximal end side, the operator can confirm that the fixing portion 10 has been accommodated inside the extraction sheath 70 without actually checking the inside of the extraction sheath 70. I understand. At this time, the proximal end portion 11 a of the biasing portion 11 is in contact with the distal end surface of the hub 72.

Next, in the extraction step (step S15), the extraction sheath 70 and the fixing portion 10 are extracted from the blood vessel. By adopting such a procedure, the fixing portion 10 does not spread or damage the blood vessel wall in the vicinity of the opening P4 when the fixing portion 10 or the lead portion 30 is removed, and the fixing portion 10 is not damaged. Can be removed safely.
After removing the nerve stimulation system 1, general hemostasis treatment such as suturing and compression is performed on the skin of the neck P <b> 8, and a series of treatments is completed.

As described above, according to the nerve stimulation system 1 of the present embodiment, since electrical stimulation can be applied to the vagus nerve P6 via the blood vessel wall without directly contacting the vagus nerve P6, it is minimally invasive. The treatment can be performed.
An extraction scale 41 is provided on the lead portion 30. The extraction scale 41 is provided at a position where the entire extraction scale 41 protrudes from the proximal end portion of the extraction sheath 70 to the proximal end side when the fixing portion 10 is housed inside the extraction sheath 70. Therefore, the operator visually recognizes that the entire extraction scale 41 protrudes from the extraction sheath 70, so that the operator can store the fixing portion 10 inside the extraction sheath 70 without directly looking inside the extraction sheath 70. It is easy to understand.
By using the extraction scale 41, it can be quantitatively understood that the fixing portion 10 is accommodated in the extraction sheath 70.
When the entire extraction scale 41 protrudes from the extraction sheath 70 to the proximal end side, the fixing portion 10 is securely stored up to the back of the sheath body 71. For this reason, it is not necessary to increase the length of the extraction sheath 70 in the axis C direction in order to securely store the fixing portion 10 in the extraction sheath 70, and the length of the extraction sheath 70 in the axis C direction is shortened. Can do.

In the nerve stimulation system of Patent Document 1, the lead body may be pushed and pulled with respect to the blood vessel due to the patient's body movement or the external force applied to the lead body pulled out of the patient's body. In this case, the electrode connected to the lead body is pushed and pulled together with the lead body, and the position and orientation of the electrode with respect to the blood vessel are shifted. In view of this, it has been studied to prevent the position and orientation of the electrodes provided on the distal end side of the lead body from shifting even when the lead body is slackened in the blood vessel and the proximal end side of the lead body is pushed and pulled.
However, it is difficult to sag reliably in the lead body inside the blood vessel that cannot be directly seen.

In contrast, according to the nerve stimulation system 1 of the present embodiment, the lead portion 30 is provided with the main scale 45a, and this main scale 45a is when the soft region 34 inserted in the blood vessel is slack. It is provided at a position that coincides with the proximal end portion of the extraction sheath 70. For this reason, when the surgeon visually recognizes that the main scale 45a coincides with the proximal end portion of the extraction sheath 70, the surgeon can surely locate the flexible region 34 in the blood vessel without directly viewing the shape of the flexible region 34. Can sag.
The slack scale set 45 includes a plurality of scales 45a, 45b, and 45c, which are a main scale 45a and auxiliary scales 45b and 45c. By selecting the scales 45a, 45b, and 45c that match the proximal end portion of the extraction sheath 70 according to the physique of the patient P, the flexible region 34 can be slackened according to the physique of the patient P.

In the nerve stimulation system of Patent Document 1, the lead body is relatively soft and it may be difficult to insert the lead body into the blood vessel. In this case, an operation sheath through which the lead main body is inserted is provided, and the lead main body and the operation sheath are temporarily engaged by an uneven shape or the like at the time of placement, so that the lead body and the entire operation sheath are hardened and easily inserted. When the lead anchor is detained at a predetermined position, the engagement between the lead main body and the operation sheath is released, and the operation sheath is pulled back with the position of the lead main body held, and removed by peel-away.
However, for example, when the lead body and the operation sheath are inserted into the blood vessel, it is difficult to determine whether or not the lead body and the operation sheath are engaged.

In contrast, according to the nerve stimulation system 1 of the present embodiment, the lead portion 30 is provided with the engagement scale 46. The engagement scale 46 is provided at a position protruding from the proximal end portion of the operation sheath 55 to the proximal end side when the engagement portion 39 and the engaged portion 59 are engaged. Therefore, when the operator visually recognizes that the engagement scale 46 protrudes from the operation sheath 55, the operator does not directly see the engagement state between the engagement portion 39 and the engaged portion 59. It can be easily seen that the engaged portion 59 is engaged.
Since it can be confirmed that the engaging portion 39 and the engaged portion 59 are engaged, the nerve stimulation system 1 is easy to handle, and the operability of the nerve stimulation system 1 is improved.

Extraction auxiliary scales 42 and 43 are provided on the proximal end side with respect to the extraction scale 41 in the lead portion 30. Therefore, before the extraction scale 41 protrudes from the extraction sheath 70, the operator can recognize that the extraction scale 41 protrudes from the extraction sheath 70 soon.
The slack scale set 45 includes a plurality of scales such as a main scale 45a and an auxiliary scale 45b. For this reason, the scale used according to a patient's physique etc. can be adjusted.

In recent years, non-pharmacological therapies that intervene in the autonomic nervous system by electrical stimulation or the like have been developed in the field of therapy for heart failure. It is known that the autonomic nervous system is also involved in the occurrence of arrhythmia after acute myocardial infarction and the occurrence of heart failure due to the progress of cardiac remodeling.
By using this nerve stimulation system to electrically stimulate the vagus nerve P6 for a certain period after reperfusion treatment for acute myocardial infarction, arrhythmia and cardiac remodeling that occur after reperfusion treatment can be reduced.

  According to the nerve stimulation system 1 of the present embodiment, the target nerve stimulation can be realized without applying a large surgical invasion to the patient when applying the electrical stimulation to the nerve tissue. The installation of the system 1 can be realized by a general transvenous approach that is frequently used in catheter procedures, and since the electrical stimulation is indirectly applied to the nerve, the system 1 can be installed without directly touching and damaging the nerve tissue. Can be installed. Then, the installation of the system 1 can be completed in a short time, and it can be quickly and safely removed after treatment.

In addition, the fixing | fixed part 10 of this embodiment can change the structure variously so that it may demonstrate below.
The fixed portion 85 shown in FIG. 16 includes a rod-like support member 86 extending from the distal end portion 33 toward the distal end side, and a biasing portion 11 curved so as to protrude from the support member 86 toward one side (one side) with respect to the axis C. Is provided. In this modification, the pair of electrode portions 20 are provided on the support member 86. The support member 86 is formed of a resin having insulating properties and elasticity.

  The fixing portion 90 shown in FIG. 17 has a so-called stent-like (cylindrical) biasing member 91 formed of an insulating and elastic resin or the like. A large number of holes 91 a are formed on the side surface of the urging member 91. By disposing the biasing member 91 in the superior vena cava P1 with the diameter reduced, the fixing portion 90 is positioned in the superior vena cava P1.

  In the fixing portion 95 shown in FIG. 18, the support wires 96 and 97 are formed on the same plane in the natural state. The support wires 96 and 97 can be formed by bending a superelastic wire. The support wires 96 and 97 are folded and reduced in diameter and introduced into the blood vessel. The support wires 96 and 97 are expanded in the superior vena cava P1 and the vessel wall P2 is urged to be fixed to the superior vena cava P1. The part 95 is positioned.

  In addition to the components of the fixing unit 10 of the present embodiment, the fixing unit 100 shown in FIG. 19 is provided with a needle portion 101 protruding toward the distal end side on the distal end side of each urging unit 11 and each urging unit. A needle portion 102 that protrudes toward the proximal end side is provided on the proximal end side of the portion 11. In the fixing part 100 configured as described above, the fixing part 100 can be positioned in the superior vena cava P1 by puncturing the blood vessel wall P2 with the needle parts 101 and 102.

As mentioned above, although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications, combinations, and deletions within a scope that does not depart from the gist of the present invention. Etc. are also included.
For example, in the above-described embodiment, the nerve stimulation system 1 includes the pair of electrode units 20, but the nerve stimulation system may include three or more electrode units 20.

It is assumed that the lead portion 30 is provided with a plurality of auxiliary scales 45b and a plurality of second auxiliary scales 45c. However, at least one auxiliary scale 45b and second auxiliary scale 45c may be provided on the front end side or the base end side of the main scale 45a.
The nerve stimulation system may not include the operation sheath 55. In this case, the lead portion 30 does not include the distal end portion 33 and the soft region 34 and is configured by a relatively hard region 35. The slack scale set 45 and the engagement scale 46 are not provided on the lead portion 30.
The engaging portion 39 is provided at both the distal end portion 33 and the fixing portion 10 of the lead portion 30. However, the engaging portion only needs to be provided on at least one of the distal end portion 33 and the fixing portion 10 of the lead portion 30. For example, the engaging portion can be provided at the distal end portion 33 of the lead portion 30 by providing the distal end portion 33 of the lead portion 30 with a receiving portion with which the distal end surface of the sheath side protrusion 60 abuts.

In the embodiment described above, the removal auxiliary scales 42 and 43 are shorter in the direction of the axis C than the removal scale 41, but the removal auxiliary scales 42 and 43 may be longer than the removal scale 41. Moreover, even if the lengths of the scales 41, 42, and 43 in the axis C direction are equal to each other, the scales 41, 42, and 43 may have different colors.
The removal assist scales 42 and 43 may not be provided in the lead portion 30. In this case, only the removal scale 41 is provided on the lead portion 30 with respect to the removal of the fixed portion 10. In this case, when a part (base end portion) of the extraction scale 41 protrudes from the extraction sheath 70 to the proximal end side, the fixing scale 10 is stored inside the extraction sheath 70, and the position where the extraction scale 41 is provided. Can be set.

  The nerve stimulation system 1 has been described as being placed in the superior vena cava P1 and applying electrical stimulation to the vagus nerve P6. However, the nerve stimulation system is not limited to this, and the electrode lead structure used in the nerve stimulation system can be used for a cardiac pacing lead, for example.

Furthermore, the present invention includes the following technical ideas.
(Additional item 1)
A fixed part formed of an elastic material, at least a pair of electrode parts provided on the fixed part, a stimulation generator for generating electrical stimulation, and a lead for electrically connecting the at least one pair of electrode parts And a removal sheath that is formed in a tubular shape so that the lead portion can be advanced and retracted, and the lead portion has a base of the removal sheath when the fixing portion is accommodated in the removal sheath. A neurostimulation system indwelling method for indwelling a nerve stimulation system provided with an extraction index part projecting from an end part to a proximal end in a blood vessel,
Inserting the fixation part into the blood vessel through an insertion tool attached to a patient;
Adjusting the position and orientation of the at least one pair of electrodes in the blood vessel so as to reduce the heart rate of the patient while applying the electrical stimulation between the at least one pair of electrodes.
Inserting the distal end side of the extraction sheath into the blood vessel;
Indwelling while applying the electrical stimulus between the at least one pair of electrode parts;
Withdrawing the lead portion to the proximal end side with respect to the extraction sheath, and projecting the extraction indicator portion from the proximal end portion of the extraction sheath to the proximal end side;
Extracting the extraction sheath and the fixing portion from the blood vessel;
A method of placing a nerve stimulation system comprising:

(Appendix 2)
The lead portion has a soft region that transmits only an elastic force that does not move the fixing portion relative to the blood vessel even if it deforms, and a proximal end side of the soft region with respect to the blood vessel. A rigid region that transmits an elastic force large enough to move the fixing portion, and a sag indicator portion that coincides with a proximal end portion of the extraction sheath when the flexible region inserted into the blood vessel is slack. Provided,
An additional item comprising a step of moving the lead portion toward the distal end side with respect to the extraction sheath after the step of inserting the distal end side of the extraction sheath, and aligning the sag indicator portion with the proximal end portion of the extraction sheath. 2. The indwelling method of the nerve stimulation system according to 1.

(Additional Item 3)
At least one of the fixed part and the tip part of the lead part is provided with an engaging part, which is formed in a cylindrical shape so that the lead part can be advanced and retracted. The axial direction of the engaging part and the lead part And an operating sheath provided at the distal end portion with an engaged portion that can be engaged around the axis, and the lead portion has a size that does not move the fixed portion relative to the blood vessel even if the lead portion is deformed. A flexible region that transmits only the elastic force, a rigid region that transmits an elastic force large enough to move the fixing portion relative to the blood vessel, and a proximal end side of the soft region; the engagement portion; An engagement indicator portion protruding from the proximal end portion of the operation sheath to the proximal end side when the engagement portion is engaged;
Is provided,
Additional Item 1 Before the step of inserting the fixing portion, the operation sheath is moved to the distal end side with respect to the lead portion, and the engagement indicator portion is protruded from the proximal end portion of the operation sheath to the proximal end side. Or the placement method of the nerve stimulation system of 2.

  In the transvascular nerve stimulation system, the risk of burdening the blood vessel when the fixing portion is pulled out from the blood vessel is suppressed, the operability of the nerve stimulation system is improved, and the stability of the fixing portion in the blood vessel is improved.

DESCRIPTION OF SYMBOLS 1 Neural stimulation system 10, 85, 90, 95, 100 Fixed part 20 Electrode part 30 Lead part 34 Soft area | region 35 Hard area | region 39 Engagement part 41 Extraction scale (extraction index part)
42, 43 Extraction assistance scale (extraction assistance indicator)
45a Main scale (sagging indicator)
45b Auxiliary scale (slack auxiliary indicator part)
45c Second auxiliary scale (slack auxiliary indicator part)
46 Engagement scale (engagement indicator)
55 Operation sheath 59 Engagement portion 70 Extraction sheath 200 Pulse generator (stimulation generator)
C axis P1 superior vena cava (blood vessel)
P5 Internal jugular vein (blood vessel)

Claims (5)

A fixing portion that is formed of an elastic material and is elastically deformed and placed in the blood vessel to urge the inner surface of the blood vessel;
At least a pair of electrode portions provided on the fixed portion;
A lead part for electrically connecting the stimulus generator for generating electrical stimulation and the at least one pair of electrode parts;
An extraction sheath that is formed in a cylindrical shape and is inserted so that the lead portion can advance and retreat, and the fixing portion is elastically deformed;
With
The nerve stimulation system, wherein the lead portion is provided with an extraction indicator portion that protrudes from the proximal end portion of the extraction sheath toward the proximal end side when the fixing portion is housed inside the extraction sheath. In the lead part,
A flexible region that transmits only an elastic force of a size that does not move the fixing part relative to the blood vessel even if it deforms;
A rigid region that transmits an elastic force of a size that moves the fixing portion relative to the blood vessel, on a proximal side of the soft region;
A sag indicator that coincides with the proximal end of the removal sheath when the soft region inserted into the blood vessel is sagging;
The nerve stimulation system according to claim 1 provided with.   The nerve stimulation system according to claim 2, wherein a sag assist indicator part is provided on a distal end side or a proximal end side of the sag indicator part in the lead part. At least one of the fixed portion and the leading end of the lead portion is provided with an engaging portion,
An operation sheath formed in a cylindrical shape so that the lead portion is inserted so as to be able to advance and retreat, and an engaged portion that can be engaged in the axial direction of the engaging portion and the lead portion and around the axis is provided at the distal end portion. Prepared,
In the lead part,
A flexible region that transmits only an elastic force of a size that does not move the fixing part relative to the blood vessel even if it deforms;
A rigid region that transmits an elastic force of a size that moves the fixing portion relative to the blood vessel, on a proximal side of the soft region;
An engagement indicator portion that protrudes from the proximal end portion of the operation sheath to the proximal end side when the engaging portion and the engaged portion are engaged;
The nerve stimulation system according to claim 1 or 2, wherein is provided. 2. The nerve stimulation according to claim 1, wherein a removal assisting index portion having a length in the axial direction of the lead portion that is different from the removal index portion is provided on a proximal end side of the lead portion with respect to the removal index portion. system.

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