WO2013024616A1

WO2013024616A1 - Electrode catheter

Info

Publication number: WO2013024616A1
Application number: PCT/JP2012/064279
Authority: WO
Inventors: 謙二森
Original assignee: 日本ライフライン株式会社
Priority date: 2011-08-15
Filing date: 2012-06-01
Publication date: 2013-02-21
Also published as: JP5769303B2; JP2013039219A

Abstract

An electrode catheter is provided with a catheter shaft (10) having a lumen (11) serving as a pathway for a fluid, and a tip electrode (20) which is connected to the tip side of the shaft (10) and has a spherical portion (21) of a diameter equal to or greater than the outer diameter of the shaft (10), the shaft (10) having a tip-end reduced diameter section (10A) where the diameter reduces in a tapered fashion toward the tip direction, a plurality of irrigation holes (112) for irrigating the surface of the tip electrode (20) with the fluid being arranged at the tip-end reduced diameter section (10A), and a plurality of tilted lumens (111) extending in the tip direction and reaching each of the irrigation openings (112) while also tilting radially outward of the shaft (10) being formed on the interior of the tip-end reduced diameter section (10A) of the shaft (10). According to this electrode catheter, the entire surface of the tip electrode having the spherical portion of a diameter equal to or greater than the outer diameter of the catheter shaft can be irrigated with the fluid from the rear-end side.

Description

Electrode catheter

The present invention relates to an electrode catheter, and more particularly to an electrode catheter having an electrode attached to the tip of the catheter and a mechanism for irrigating a liquid such as physiological saline to the electrode.

In the ablation catheter that is an electrode catheter, in order to cool the tip electrode that has become hot during cauterization and to stir and dilute blood around the tip electrode to prevent thrombus formation on the tip electrode surface, Those equipped with an irrigation mechanism are used.

As a conventional catheter provided with an irrigation mechanism, a catheter that injects physiological saline supplied through the catheter shaft into the tip electrode from a plurality of openings formed on the surface of the tip electrode has been introduced. (For example, see Patent Document 1 and Patent Document 2).

Japanese Patent No. 2566281 JP 2006-239414 A

However, conventionally known catheters in which an irrigation opening is formed on the surface of the tip electrode have the following problems (1) to (4).

(1) When an opening is provided on the surface of the tip electrode, an edge is inevitably formed at the opening edge or the like. When cauterization is performed with the tip electrode having such an edge, the current density in the edge portion becomes extremely high, and an abnormal temperature rise occurs in this portion, so that a thrombus may be rapidly formed. .
(2) Even if physiological saline is injected from the opening formed on the surface of the tip electrode, sufficient irrigation cannot be performed on the surface of the tip electrode (the surface is covered with a liquid). The surface cannot be sufficiently cooled, and the formation of thrombus on the surface cannot be sufficiently prevented or suppressed. In particular, in the catheters described in Patent Document 1 and Patent Document 2 that inject physiological saline in a direction perpendicular to the axis of the tip electrode, the saline can be sufficiently brought into contact with the surface of the tip electrode. Therefore, the effect of cooling the electrode surface and the effect of suppressing thrombus formation are extremely low.
(3) By forming a plurality of openings on the electrode surface, it is impossible to ensure a sufficient surface area of the tip electrode, and efficient cauterization treatment cannot be performed.
(4) A temperature sensor such as a thermocouple is usually mounted inside the distal electrode constituting the ablation catheter in order to control the ablation temperature. However, when an opening for irrigation is formed on the surface of the tip electrode (a saline flow path is formed inside the tip electrode), the temperature sensor is excessive due to the saline flowing through the flow path. As a result of the cooling, the temperature of the tissue around the tip electrode cannot be accurately measured and is detected low, and as a result, the ablation temperature may be increased more than necessary.

In order to solve the problems (1) to (4), it is conceivable to irrigate the liquid from the outside (rear end side) with respect to the surface of the tip electrode.
However, when an opening for irrigating liquid on the surface of the tip electrode is formed on the tip surface of the catheter shaft (tip surface perpendicular to the shaft axis), the tip electrode capable of irrigating the liquid is extremely small (for example, When a plurality of openings are arranged on the circumference, the size fits inside the circumference), and efficient ablation treatment cannot be performed by an ablation catheter equipped with such a tip electrode. .
On the other hand, when the irrigation opening is formed on the outer peripheral surface of the catheter shaft, the liquid from the opening is ejected in a direction perpendicular to the shaft axis and cannot be ejected toward the tip electrode.

The present invention has been made based on the above situation.
A first object of the present invention is to provide an electrode catheter capable of irrigating a liquid from the rear end side with respect to the surface of the tip electrode having a spherical portion having a diameter equal to or larger than the outer diameter of the catheter shaft.
A second object of the present invention is to provide an electrode catheter capable of irrigating a liquid over the entire surface of the tip electrode having a spherical portion having a diameter equal to or larger than the outer diameter of the catheter shaft.
The third object of the present invention is that an abnormal temperature rise (high temperature part) does not occur in a part of the tip electrode during cauterization, and is excellent in the cooling effect of the tip electrode surface and the thrombus formation suppressing effect on the tip electrode surface. And it is providing the electrode catheter provided with the irrigation mechanism which can perform an efficient cauterization treatment.
A fourth object of the present invention is to provide an electrode catheter equipped with an irrigation mechanism that can accurately measure the temperature of the tissue around the tip electrode and can appropriately control the ablation temperature. It is in.

(1) The electrode catheter of the present invention includes a catheter shaft having a lumen serving as a liquid flow path,
Connected to the distal end side of this catheter shaft, comprising a tip electrode having a spherical portion with a diameter equal to or larger than the outer diameter of the catheter shaft,
The catheter shaft has a distal diameter-reduced portion that is tapered in the distal direction, and the distal diameter-reduced portion has a plurality of irrigation openings for irrigating liquid on the surface of the distal electrode. Arranged,
A plurality of inclined lumens extending in the distal direction while being inclined radially outward of the catheter shaft and reaching each of the irrigation openings are formed inside the reduced diameter portion of the catheter shaft. To do.

According to the electrode catheter having such a configuration, a plurality of irrigation openings are arranged in the reduced diameter portion of the catheter shaft, so that the liquid ejected from each of the plurality of irrigation openings is directed in the distal direction. Therefore, the liquid can be ejected from the rear end side with respect to the surface of the tip electrode.
The liquid sprayed to the tip electrode from each of the plurality of irrigation openings flows in the tip direction along the surface of the tip electrode, so that the surface of the tip electrode is cooled compared to a conventional catheter having an irrigation mechanism. In addition to being excellent in effect, the blood in the vicinity of the surface of the tip electrode is sufficiently agitated and diluted to exert an excellent thrombus formation suppressing effect.

Further, a plurality of inclined lumens extending in the distal direction while being inclined radially outward of the catheter shaft and reaching each of the irrigation openings are formed inside the reduced diameter portion of the catheter shaft. Even if the diameter of the spherical part (the maximum diameter of the tip electrode) is equal to or larger than the outer diameter of the catheter shaft, the liquid ejected from the irrigation opening through this inclined lumen reaches the electrode surface at the maximum diameter part of the tip electrode. And irrigating the entire surface of the tip electrode including the maximum diameter portion and the tip side thereof.

Further, according to the electrode catheter having such a configuration, since the irrigation opening is formed in the catheter shaft, it is not necessary to form an opening in the tip electrode. As a result, since there is no edge associated with the formation of the opening in the tip electrode, an abnormal temperature rise does not occur in a part of the tip electrode during cauterization, thereby suppressing thrombus formation.
Therefore, the electrode catheter of the present invention is remarkably superior in the thrombus formation suppressing effect on the tip electrode surface as compared with a conventionally known catheter having an irrigation mechanism.

In addition, since the diameter of the spherical portion of the tip electrode is equal to or larger than the outer diameter of the catheter shaft, and it is not necessary to form an opening in the tip electrode, a sufficient surface area can be secured, and an efficient cauterization as an ablation catheter Can be treated.

(2) In the electrode catheter of the present invention, the ratio (D ₂ / D ₁ ) of the diameter (D ₂ ) of the spherical portion of the tip electrode to the outer diameter (D ₁ ) of the catheter shaft is 1.0 to 1.2. And
The distance in the axial direction from the rear end of the reduced diameter portion of the catheter shaft to the distal end edge of the irrigation opening (L ₁ ), and the shaft from the distal end edge of the irrigation opening to the maximum diameter portion of the distal electrode When the axial distance is (L ₂ ), the inclination angle at the reduced diameter portion of the catheter shaft is (β), and the inclination angle of the inclined lumen is (α),
Formula: 0.8D ₂ ≦ D ₁ +2 (L ₂ tan α−L ₁ tan β) ≦ 1.2 D ₂
Is preferably established.

According to the electrode catheter having such a configuration, the liquid ejected from the irrigation opening through the inclined lumen reaches the electrode surface at the maximum diameter portion of the tip electrode, and reliably covers the entire surface of the tip electrode. Can be irrigated.
The “irrigation opening” may be formed across the distal diameter-reduced portion of the catheter shaft and the rear end portion of the distal electrode, and the distal edge of the irrigation opening in such a case is the rear end portion of the distal electrode. Will exist.

(3) In the electrode catheter of (2), the catheter shaft diameter (D ₁ ) is 1.0 to 3.0 mm,
The distance (L ₁ ) is 0.5 to 5.0 mm,
The distance (L ₂ ) is 1.5 to 7.0 mm,
The inclination angle (β) is 5.0 to 30.0 °,
The inclination angle (α) is preferably 5.0 to 30.0 °.

(4) In the electrode catheter of the present invention, the ratio (D ₂ / D ₁ ) of the diameter (D ₂ ) of the spherical portion of the tip electrode to the outer diameter (D ₁ ) of the catheter shaft is 1.0 to 1.2. And
The outer diameter of the tip diameter-reduced portion or the tip electrode (non-spherical portion) at the tip edge of the irrigation opening is (D ₃ ), and the shaft axis from the tip edge of the irrigation opening to the maximum diameter portion of the tip electrode When the direction distance is (L ₂ ) and the inclination angle of the inclined lumen is (α),
Formula: 0.8D ₂ ≦ D ₃ +2 (L ₂ · tan α) ≦ 1.2D ₂
Is preferably established.

According to the electrode catheter having such a configuration, the liquid ejected from the irrigation opening through the inclined lumen reaches the electrode surface at the maximum diameter portion of the tip electrode, and reliably covers the entire surface of the tip electrode. Can be irrigated.

(5) In the electrode catheter of the present invention, it is preferable that a temperature sensor is attached to the distal end side of the irrigation opening, specifically, a temperature sensor is attached to the inside of the distal electrode.

According to the electrode catheter having such a configuration, since the liquid flow path is not formed inside the tip electrode to which the temperature sensor is attached, the temperature sensor is not excessively cooled, and the periphery of the tip electrode Therefore, the temperature of the tissue can be accurately measured, and appropriate control of the ablation temperature can be performed.

(6) In the electrode catheter of the present invention, the catheter shaft is a multi-lumen structure having a central lumen and a plurality of sub-lumens arranged at equiangular intervals around the central lumen,
Among the plurality of sub-lumens, two sub-lumens arranged opposite to each other are inserted with a pull wire for deflection operation of the shaft tip, and the other sub-lumens constitute a lumen serving as a liquid flow path. ,
The inclined lumen is preferably formed so as to communicate with each of the lumens serving as the liquid flow paths.

According to the electrode catheter of the present invention, it is possible to irrigate the liquid from the rear end side over the entire surface of the tip electrode having a spherical portion having a diameter equal to or larger than the outer diameter of the catheter shaft.
According to the electrode catheter of the present invention, an abnormal temperature rise does not occur in a part of the tip electrode during cauterization, it is excellent in the effect of cooling the surface of the tip electrode and the effect of suppressing thrombus formation on the surface of the tip electrode, Can perform efficient cauterization treatment.

It is a front view of the ablation catheter which concerns on one Embodiment of the electrode catheter of this invention. FIG. 2 is a transverse sectional view (II-II sectional view of FIG. 1) of a catheter shaft constituting the ablation catheter shown in FIG. FIG. 3 is a longitudinal sectional view showing the inside of the distal end portion of the ablation catheter shown in FIG. FIG. 3 is a longitudinal sectional view showing the inside of the distal end portion of the ablation catheter shown in FIG. It is a longitudinal cross-sectional view which shows the inside of the front-end | tip part of the ablation catheter which concerns on other embodiment of the electrode catheter of this invention. It is a longitudinal cross-sectional view which shows the inside of the front-end | tip part of the ablation catheter which concerns on other embodiment of the electrode catheter of this invention.

<First Embodiment>
Hereinafter, an embodiment of an electrode catheter of the present invention will be described with reference to the drawings.
The electrode catheter shown in FIGS. 1 to 4A is an ablation catheter used for the treatment of arrhythmia in the heart.

The ablation catheter 100 of this embodiment includes a central lumen 13 through which a lead wire and the like are passed, and 10 sub-lumens (eight serving as a liquid flow path) arranged at equiangular intervals (36 ° intervals) around the central lumen 13. A catheter shaft 10 having two lumens 12) serving as insertion passages for the lumen 11 and the pulling

wires

31, 32, and a catheter shaft 10 connected to the distal end side of the catheter shaft 10 and having an outer diameter (D ₁ ) or larger. A tip electrode 20 having a spherical portion 21 having a diameter (D ₂ ), a ring electrode 40 attached to the tip portion of the catheter shaft 10, a control handle 70 connected to the rear end side of the catheter shaft 10, and a liquid An injection tube 80 and a temperature sensor (thermocouple) 90 mounted inside the tip electrode 20 are provided. The tip diameter-reduced portion 10A is tapered toward the tip direction, and eight irrigation openings 112 for irrigating the liquid on the surface of the tip electrode 20 are disposed in the tip diameter-reduced portion 10A. The distal end diameter-reduced portion 10A of the catheter shaft 10 communicates with each of the eight lumens 11 on the rear end side, and extends in the distal direction while inclining radially outward of the catheter shaft 10 so as to open for irrigation. Eight inclined lumens 111 extending to each of 112 are formed.

Here, FIG. 3 and FIG. 4A have shown the longitudinal cross-section cut | disconnected by the plane containing the central axis of the central lumen 13 and the two lumens 11 shown in FIG.
Therefore, in FIG. 3 and FIG. 4A, two lumens 11 of “eight lumens 11 serving as liquid flow paths”, two inclined lumens 111 of “eight inclined lumens 111”, “ Only two irrigation openings 112 of the eight irrigation openings 112 "are shown.

1 is connected to the catheter shaft 10 through the inside of the control handle 70, and the liquid is supplied to the lumen 11 of the catheter shaft 10 through the injection tube 80. Here, as the “liquid”, physiological saline can be exemplified.

The control handle 70 shown in FIG. 1 is connected to the rear end side of the catheter tube 10 and includes a rotating plate 75 for performing a tip deflection operation of the catheter.

As shown in FIG. 2, the catheter shaft 10 constituting the ablation catheter 100 is provided with a central lumen 13 through which a conducting wire (not shown) connected to the tip electrode 20 and the ring electrode 40 is passed, and the central lumen. Ten sub-lumens arranged at equiangular intervals (36 ° = 360 ° / 10) around 13 are formed.

Ten sub-lumens formed at equal intervals around the central lumen 13 have the same outer diameter.

Tensile wires

31 and 32 for performing a tip deflection operation of the catheter are inserted into two lumens 12 of the ten sub-lumens, respectively.
The eight lumens 11 through which the pulling

wires

31 and 32 are not inserted constitute a liquid flow path.

2, the rear ends of the

tension wires

31 and 32 are connected to the rotating plate 75 (see FIG. 1) of the control handle 70, and the distal ends of the

tension wires

31 and 32 are, for example, the distal end portion of the catheter shaft 10. The connection is fixed.
Thereby, for example, when the rotating plate 75 is rotated in the A1 direction shown in FIG. 1, the pulling wire 31 is pulled, and the distal end portion of the ablation catheter 100 is deflected in the arrow A direction and rotated in the B1 direction shown in FIG. When the plate 75 is rotated, the pulling wire 32 is pulled, and the distal end portion of the ablation catheter 100 is deflected in the arrow B direction.

Reference numeral 15 denotes a rigid body embedded in the catheter shaft 10 in order to surely perform the deflection operation by the pulling

wires

31 and 32.
The rigid body 15 is made of a metal bar spring such as a Ni—Ti alloy, and has different bending directions due to the

rigid bodies

15 and 15 arranged in a direction perpendicular to the bending direction (the arrangement direction of the tension wires 31 and 32). The direction can be secured.

The catheter shaft 10 may be made of a material having the same characteristics along the axial direction, but is preferably formed integrally using materials having different rigidity (hardness) along the axial direction. Specifically, it is preferable that the constituent material on the proximal end side has relatively high rigidity, and the constituent material on the distal end side has relatively low rigidity.

The catheter shaft 10 is made of a synthetic resin such as polyolefin, polyamide, polyether polyamide, polyurethane, nylon, or PEBAX (polyether block amide). The proximal end side of the catheter shaft 10 may be a blade tube obtained by braiding a tube made of these synthetic resins with a stainless steel wire.

The outer diameter (D ₁ ) of the catheter shaft 10 (the outer diameter of the portion other than the reduced diameter portion 10A) is preferably 1.0 to 3.0 mm, more preferably 1.3 to 3.0 mm, and particularly preferably. Is 1.6 to 2.7 mm.
The length of the catheter shaft 10 is preferably 600 to 1500 mm, and more preferably 900 to 1200 mm.

As shown in FIGS. 3 and 4A, the catheter shaft 10 has a distal diameter-reducing portion 10A that is reduced in diameter toward the distal direction, and an inclined lumen 111 is formed inside the distal-diameter reduced portion 10A. ing.
The inclined lumen 111 communicates with the lumen 11 that is a liquid flow path on the rear end side, extends in the distal direction while being inclined outward in the radial direction of the catheter shaft 10, and opens on the outer peripheral surface of the reduced diameter portion 10 </ b> A. is doing. This opening is the irrigation opening 112, and eight irrigation openings 112 are formed along the outer periphery of the tip reduced diameter portion 10A.
In the present invention, the rear end side of the inclined lumen may extend to the inside of the shaft portion located on the rear end side from the tip reduced diameter portion.

Each of the inclined lumens 111 extends in the distal direction while being inclined outward in the radial direction of the catheter shaft 10. Thereby, the liquid ejected from the irrigation opening 112 through the inclined lumen 111 is ejected toward the distal end side in the axial direction of the catheter shaft 10 and outward in the radial direction. For this reason, it is possible to irrigate the surface of the tip electrode (tip electrode 20 having a spherical portion with a diameter equal to or larger than the outer diameter of the catheter shaft 10) having a certain size.

The distal electrode 20 constituting the ablation catheter 100 has a spherical portion 21, a neck portion 22, and a cylindrical portion 23.
As shown in FIGS. 3 and 4A, the distal electrode 20 is connected to the distal end side of the catheter shaft 10 by the cylindrical portion 23 being inserted and fixed inside the distal reduced diameter portion 10A.

The diameter (D ₂ ) of the spherical portion 21 corresponding to the maximum diameter of the tip electrode 20 is preferably 1.0 to 3.6 mm, more preferably 1.3 to 3.0 mm, and particularly preferably 2.2 to 2.6 mm.

The ratio (D ₂ / D ₁ ) of the diameter (D ₂ ) of the spherical portion 21 of the tip electrode 20 to the outer diameter (D ₁ ) of the catheter shaft 10 is usually 1.0 or more, preferably 1.0 to 1.2.
When the ratio (D ₂ / D ₁ ) is 1.0 or more, the ablation catheter 100 has a constricted shape (the constricted portion of the reduced diameter portion 10A of the catheter shaft 10 and the neck portion 22 of the distal electrode 20). Become).

When the value of (D ₂ / D ₁ ) is too small, it becomes difficult to perform efficient cauterization treatment with a catheter provided with such a tip electrode.
On the other hand, when the value of (D ₂ / D ₁ ) is excessive, a sufficient amount of liquid is irrigated onto the surface of such a tip electrode (a sufficient cooling effect and thrombus formation suppressing effect is obtained). It is difficult to express).

As shown in FIGS. 3 and 4A, a temperature sensor 90 made of a thermocouple or the like for controlling the ablation temperature is mounted inside the tip electrode 20. Further, the conducting wire 95 connected to the temperature sensor 90 is drawn through the central lumen 13.
When the ablation catheter 100 is used (at the time of ablation treatment), the temperature sensor 90 measures the temperature of the tissue around the tip electrode 20, and this measurement temperature is fed back to control the ablation temperature (adjustment of high-frequency energy). .

In the ablation catheter 100 of this embodiment, the distance in the axial direction of the shaft from the rear end of the diameter-reduced portion 10A of the catheter shaft 10 to the tip edge of the irrigation opening 112 (the portion of the opening edge closest to the tip). (L ₁ ), the distance in the axial direction of the shaft from the distal edge of the irrigation opening 112 to the maximum diameter portion of the distal electrode 20 (L ₂ ), and the inclination angle in the reduced diameter portion 10 A of the catheter shaft 10 (β) When the inclination angle of the inclined lumen 111 is (α), the following equation is established.

Formula: D ₁ +2 (L ₂ · tan α−L ₁ · tan β) ≈D ₂

Here, the outer diameter (the diameter of a circle connecting each of the plurality of tip edges) of the tip reduced diameter portion 10A on the tip edge of the irrigation opening 112 can be expressed as D ₁ -2 · L ₁ · tan β. .
On the other hand, the liquid ejected in the distal direction from the distal edge of the irrigation opening 112 at the ejection angle equal to the inclination angle (α) of the inclined lumen 111 moves the shaft axis while moving the distance (L ₂ ) in the shaft axis direction. The distance L ₂ · tan α is moved in a direction perpendicular to the direction (radial direction of the shaft).
As a result, when the liquid ejected from the leading edge of the irrigation opening 112 moves a distance (L ₂ ) in the shaft axial direction, the diameter of the imaginary circle connecting the positions where the liquid reaches is D ₁ -2 · L ₁ · tan β + 2 · L ₂ · tan α = D ₁ +2 (L ₂ · tan α−L ₁ · tan β).
Therefore, according to the ablation catheter 100 of this embodiment, the above formula is satisfied (the diameter of the virtual circle substantially matches the diameter (D ₂ ) of the spherical portion). The liquid thus made can reach the electrode surface at the maximum diameter portion of the tip electrode 20.
Here, in FIG. 4A, an extrapolated line EX obtained by extrapolating (extending) an inner straight line defining the inclined lumen 111 schematically shows a path of liquid ejected from the tip edge of the irrigation opening 112. .
Actually, since the liquid is ejected in the blood, the ejected liquid proceeds while diffusing.

The distance in the axial direction of the shaft from the rear end of the reduced diameter portion 10A of the catheter shaft 10 to the front end edge of the irrigation opening 112 (projection distance to the central axis of the catheter shaft 10) (L ₁ ) is 0.5-5. It is preferably 0 mm, and more preferably 1.0 to 3.0 mm.
If this distance (L ₁ ) is too small, the tilt angle of the tilt lumen 111 cannot be designed to be small, and the ejected liquid will spread too much, so that the liquid reaches the tip electrode 20 sufficiently. There is a risk that it will not.
On the other hand, when the distance (L ₁ ) is excessive, the distance of the inclined lumen 111 becomes too long, and the processing becomes difficult. Further, since the ring-shaped electrode 40 cannot be provided on the inclined lumen 111, the distance between the ring-shaped electrode 40 and the tip electrode 20 becomes excessive, and it becomes difficult to design in accordance with a request to reduce the distance between these electrodes. Also occurs.

The inclination angle (β) at the distal diameter reduced portion 10A of the catheter shaft 10 is preferably 5.0 to 30.0 °, and more preferably 7.0 to 20.0 °.

When the inclination angle (β) is too small, it is necessary to design the distance (L ₁ ) excessively in order to obtain the inclination angle of the inclined lumen 111, which causes the same problem as described above.
On the other hand, when the inclination angle (β) is excessive, the distance of the inclined lumen 111, in particular, the distance to the rear edge of the irrigation opening 112 (in FIG. 4A, the linear distance outside the section defining the inclined lumen 111). ) Becomes smaller, and the guide function of pushing the ejected liquid toward the tip may be impaired. In this case, the liquid to be ejected immediately spreads too much in the outer diameter direction, resulting in excessive diffusion.

−2 · L ₁ · tan β according to the above expression corresponds to the amount of diameter reduction of the tip diameter reducing portion 10A up to the tip edge of the irrigation opening 112.
When 2 · L ₁ · tan β is excessive, the diameter of the catheter shaft is excessive, which makes it difficult to design the entire catheter.

The distance in the shaft axis direction (projection distance onto the central axis of the catheter shaft 10) (L ₂ ) from the distal edge of the irrigation opening 112 to the maximum diameter portion of the distal electrode 20 is 1.5 to 7.0 mm. The thickness is preferably 3.0 to 5.0 mm.

When this distance (L ₂ ) is too small, it becomes difficult for the liquid ejected from the irrigation opening to be blocked by the rear end portion of the spherical portion and reach the maximum diameter portion.
On the other hand, when this distance (L ₂ ) is excessive, it becomes difficult for the liquid ejected from the irrigation opening to reach the maximum diameter portion.

The inclination angle (α) of the inclined lumen 111 is preferably 5.0 to 30.0 °, and more preferably 9.0 to 15.0 °.
When the inclination angle (α) is too small, it becomes difficult for the liquid ejected from the irrigation opening to be blocked by the rear end portion of the spherical portion and reach the maximum diameter portion.
On the other hand, when this inclination angle (α) is excessive, it becomes difficult to direct the liquid ejected from the irrigation opening toward the distal end, and it is possible to efficiently reach the electrode surface of the maximum diameter portion. become unable.

2 · L ₂ · tan α according to the above formula indicates the degree of spread of the liquid to be ejected.
When 2 · L ₂ · tan α is excessive, it is difficult to direct the liquid ejected from the irrigation opening toward the distal end, and it becomes impossible to efficiently reach the electrode surface of the maximum diameter portion. .

As a preferable example of the ablation catheter 100 of this embodiment, the outer diameter (D ₁ ) is 2.3 mm, the diameter (D ₂ ) is 2.6 mm, and the value of (D ₂ / D ₁ ) is 1.1. The distance (L ₁ ) is 1.0 mm, the inclination angle (β) is 12.0 °, the distance (L ₂ ) is 2.8 mm, the inclination angle (α) is 7.0 °, and D ₁ +2 (L ₂ Tan α−L ₁ tan β) = 2.6 mm, which is almost equal to the diameter (D ₂ ).

According to the ablation catheter 100 of this embodiment, the eight irrigation openings 112 are arranged in the tapered distal diameter-reducing portion 10A, so that the liquid ejected from each of the irrigation openings 112 is directed in the distal direction. Therefore, the liquid can be ejected from the rear end side with respect to the surface of the tip electrode 20.
Then, the liquid ejected from the rear end side (each of the irrigation openings 112 arranged in the distal diameter-reduced portion 10A of the catheter shaft 10) with respect to the distal electrode 20 is the rear end portion (neck portion) of the distal electrode 20 22) from the tip portion (spherical portion 21) toward the tip direction along the surface of the tip electrode 20, and blood around the tip electrode 20 is sufficiently agitated / diluted so that an irrigation mechanism is provided. Compared to a conventional catheter, the effect of cooling the surface of the tip electrode 20 is excellent, and an excellent effect of suppressing thrombus formation is also obtained by sufficiently stirring and diluting the blood near the surface of the tip electrode 20.

In addition, eight inclined lumens 111 extending in the distal direction while being inclined outward in the radial direction of the catheter shaft 10 and reaching each of the irrigation openings 112 are formed inside the reduced diameter portion 10A of the catheter shaft 10. Therefore, the liquid ejected from each of the irrigation openings 112 is ejected toward the outer side in the distal direction (the distal side in the axial direction of the catheter shaft 10 and the outer side in the radial direction). Here, the liquid ejection angle coincides with the inclination angle (α) of the inclined lumen 111.

Further, when the formula: D ₁ +2 (L ₂ · tan α−L ₁ · tan β) ≈D ₂ is established, the spherical portion 21 of the tip electrode 20 is equal to or larger than the outer diameter of the catheter shaft 10 (in particular, the outer diameter (D ₁ Even if the liquid has a diameter (D ₂ ) that is 1.0 to 1.2 times larger than), the liquid ejected from the irrigation opening 112 through the inclined lumen 111 is allowed to flow at the maximum diameter portion of the tip electrode 20. The electrode surface can be reached, and the entire surface of the tip electrode 20 including the maximum diameter portion and the tip side can be reliably irrigated.

In addition, since the irrigation opening 112 is formed in the insulating catheter shaft 10 (tip reduced diameter portion 10A) and the conductive tip electrode 20 has no edge, when the ablation catheter 100 is used (at the time of cauterization). In this case, an abnormal temperature rise (high temperature part) does not occur in a part of the tip electrode 20, and the formation of thrombus formed by contact of blood with such high temperature part is suppressed.

The diameter (D ₂ ) of the spherical portion 21 of the tip electrode 20 is not less than the outer diameter (D ₁ ) of the catheter shaft 10, particularly 1.0 to 1.2 times the outer diameter (D ₁ ). Since it is not necessary to form an irrigation opening in the electrode 20, a sufficient surface area can be secured, and efficient ablation treatment can be performed as an ablation catheter.

In addition, since the temperature sensor 90 is attached to the tip side of the irrigation opening 112, there is no need to form a liquid flow path inside the tip electrode 20 to which the temperature sensor 90 is attached. 90 is not excessively cooled, and the temperature of the tissue around the tip electrode 20 can be accurately measured.

In the ablation catheter 100 shown in FIG. 4A, the value of D ₁ +2 (L ₂ · tan α−L ₁ · tan β) was substantially equal to D _2. , if the range value of _{_{D 1 +2 (L 2 · tanα}} -L 1 · tanβ) of 0.8D ₂ ~ 1.2D _2, the liquid ejected from the irrigation opening, the maximum diameter of the tip electrode It was confirmed that the electrode surface could be reached and that the entire surface of the tip electrode could be reliably irrigated.

When the value of D ₁ +2 (L ₂ · tan α−L ₁ · tan β) is less than 0.8D ₂ , the liquid ejected from the irrigation opening is blocked by the rear end portion of the spherical portion and reaches the maximum diameter portion. It may be difficult to reach.
On the other hand, when the value of D ₁ +2 (L ₂ · tan α−L ₁ · tan β) exceeds 1.2D ₂ , it becomes difficult to direct the liquid ejected from the irrigation opening toward the distal end. It may not be possible to efficiently reach the electrode surface of the diameter portion.

<Second Embodiment>
The ablation catheter 101 shown in FIG. 4B includes a catheter shaft 50 having ten sub-lumens (eight lumens 11 serving as liquid flow paths and two lumens serving as insertion passages for the pulling wire). The catheter shaft 50 has a distal diameter-reducing portion 50A that is tapered toward the distal direction, and the distal diameter-reduced portion 50A has eight irrigation for irrigating the surface of the distal electrode 20. An opening for use 114 is arranged, and the inside of the reduced diameter portion 50A of the catheter shaft 50 communicates with each of the eight lumens 11 on the rear end side, and in the distal direction while inclining radially outward of the catheter shaft 10. Eight inclined lumens 113 extending to each of the irrigation openings 114 are formed.

In FIG. 4B, the same reference numerals are used for the same components as those of the ablation catheter 100 shown in FIG. 4A.
4B, two lumens 11 of “eight lumens 11 serving as liquid flow paths”, two inclined lumens 113 of “eight inclined lumens 113”, “eight irrigation” Two of the irrigation openings 114 "are shown.

In this ablation catheter 101, the inclination angle (α) of the inclined lumen 113 formed inside the distal diameter reduced portion 50A of the catheter shaft 50 is equal to the inclination angle (α) of the inclined lumen 111 in the ablation catheter 100 shown in FIG. 4A. ) Is different.
Here, if a suitable example of the ablation catheter 101 is shown, the outer diameter (D ₁ ) is 2.3 mm, the outer diameter (D ₂ ) is 2.6 mm, and the value of (D ₂ / D ₁ ) is 1.1, The distance (L ₁ ) is 1.0 mm, the inclination angle (β) is 7.0 °, the distance (L ₂ ) is 2.8 mm, the inclination angle (α) is 10.5 °, and D ₁ +2 (L ₂ Tan α−L ₁ tan β) = 3.1 mm, which is approximately 1.2 times the diameter (D ₂ ).

According to the ablation catheter 101 of this embodiment, the liquid ejected from the tip edge of the irrigation opening 114 can reach the electrode surface at the maximum diameter portion of the tip electrode 20, and the entire surface of the tip electrode 20 can be obtained. Can be reliably irrigated.

<Third Embodiment>
The ablation catheter 102 shown in FIG. 4C includes a catheter shaft 60 having 10 sub-lumens (eight lumens 11 serving as liquid flow paths and two lumens serving as insertion passages for the tension wires). The catheter shaft 60 has a distal diameter-reducing portion 60A that decreases in a taper shape toward the distal direction, and the distal diameter-reduced portion 60A includes eight irrigations for irrigating the surface of the distal electrode 20. An opening 116 is disposed, and the inside of the reduced diameter portion 60A of the catheter shaft 60 communicates with each of the eight lumens 11 on the rear end side, and in the distal direction while inclining radially outward of the catheter shaft 10. Eight inclined lumens 115 are formed extending to each of the irrigation openings 116.

In FIG. 4C, the same reference numerals are used for the same components as those of the ablation catheter 100 shown in FIG. 4A.
4C, two lumens 11 of “eight lumens 11 serving as liquid flow paths”, two inclined lumens 115 of “eight inclined lumens 115”, “eight irrigation” Two of the irrigation openings 116 "are shown.

The rear end portion (neck portion 22) of the distal electrode 20 constituting the ablation catheter 102 is continuous with each of the inclined lumens 115 and is inclined at the same angle as the inclination angle (α) of the inclined lumen 115. Is formed.
Accordingly, the irrigation opening 116 is formed across the distal diameter-reduced portion 60A of the catheter shaft 60 and the neck portion 22 of the distal electrode 20, and the distal edge of such an irrigation opening 116 is formed on the distal electrode 20. It exists in the neck part 22.
By forming the guide groove 26, the spray angle of the liquid sprayed from the tip edge of the irrigation opening 116 located in the neck portion 22 of the tip electrode 20 coincides with the tilt angle (α) of the tilt lumen 115. Can be made.

In the ablation catheter 102 shown in FIG. 4C, the outer diameter of the distal electrode 20 (neck portion 22) at the distal edge of the irrigation opening 116 is (D ₃ ), and the maximum diameter portion of the distal electrode 20 from the distal edge of the irrigation opening 116 (L ₂ ) and the inclination angle of the inclined lumen 115 is (α), the value of D ₃ +2 (L ₂ · tan α) is approximately 0.8D ₂ .

In this ablation catheter 102, the inclination angle (α) of the inclined lumen 115 formed inside the distal diameter reduced portion 60A of the catheter shaft 60 is such that the inclined lumen 111 in the ablation catheter 100 shown in FIG. 4A and FIG. It differs from any inclination angle (α) of the inclined lumen 113 in the ablation catheter 101 shown in FIG.

As a preferred example of the ablation catheter 102, the outer diameter (D ₁ ) is 2.3 mm, the outer diameter (D ₂ ) is 2.8 mm, the value of (D ₂ / D ₁ ) is 1.2, and the irrigation opening The outer diameter (D ₃ ) of the tip electrode 20 at the tip edge of 116 is 1.7 mm, the distance (L ₁ ) is 2.4 mm, the inclination angle (β) is 7.0 °, and the distance (L ₂ ) is 1.4 mm. The inclination angle (α) is 12.0 °, and D ₃ +2 (L ₂ · tan α) = 2.3 mm, which is approximately 0.8 times the diameter (D ₂ ).

According to the ablation catheter 102 of this embodiment, the liquid ejected from the tip edge of the irrigation opening 116 can reach the electrode surface at the maximum diameter portion of the tip electrode 20, and the entire surface of the tip electrode 20 can be obtained. Can be reliably irrigated.

In the ablation catheter 102 shown in FIG. 4C, the value of D ₃ +2 (L ₂ · tan α) was almost equal to 0.8D ₂ , but as a result of extensive studies by the present inventor, D ₃ +2 If the value of (L ₂ · tan α) is in the range of 0.8D ₂ to 1.2D ₂ , the liquid ejected from the irrigation opening can reach the electrode surface at the maximum diameter portion of the tip electrode, It was confirmed that the entire surface of the tip electrode can be irrigated.

When the value of D ₃ +2 (L ₂ · tan α) is less than 0.8D ₂ , it is difficult for the liquid ejected from the irrigation opening to be blocked by the rear end portion of the spherical portion and reach the maximum diameter portion. It may become.
On the other hand, when the value of D ₃ +2 (L ₂ · tan α) exceeds 1.2D ₂ , it becomes difficult to direct the liquid ejected from the irrigation opening toward the tip, and the electrode surface having the maximum diameter portion May not be able to be reached efficiently.

As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible.
For example, the number of inclined lumens formed inside the tip diameter-reduced portion is not limited to 8, and can be appropriately selected within a range of 4 to 12, for example.
Further, by interposing an intermediate member (an intermediate member having a means for joining and / or diverting liquid) between the tip reduced diameter portion and a portion other than the tip reduced diameter portion, the inside of the tip reduced diameter portion The number of the inclined lumens formed on the inner surface may be different from the number of the lumens (lumens serving as a liquid flow path) formed inside the portion other than the tip diameter-reduced portion.
Further, as a constituent material of the tip reduced diameter portion (or the tip portion including the tip reduced diameter portion) in which the inclined lumen is formed, a material different from the constituent material of the shaft portion other than the tip reduced diameter portion (for example, polyether ether) Aromatic polyether ketone such as ketone (PEEK), ceramic material, etc.) may be employed.

DESCRIPTION OF SYMBOLS 100 Ablation catheter 10 Catheter shaft 10A Tip diameter reducing part 11 Lumen (liquid flow path)
12 lumens (Tension wire insertion path)
13 Central lumen 15 Rigid body (wire)
111 Inclined lumen 112 Irrigation opening 20 Tip electrode 21 Tip bulging portion 22 Neck portion 23 Cylindrical portion 26 Liquid guide groove 31 Tension wire 32 Tension wire 40 Ring electrode 50 Catheter shaft 50A Tip diameter reduction portion 113 Tilted lumen 114 Irrigation Opening 60 catheter shaft 60A reduced diameter portion 115 inclined lumen 116 irrigation opening 70 control handle 75 rotating plate 80 liquid injection tube

Claims

A catheter shaft having a lumen that serves as a liquid flow path;
Connected to the distal end side of this catheter shaft, comprising a tip electrode having a spherical portion with a diameter equal to or larger than the outer diameter of the catheter shaft,
The catheter shaft has a distal diameter-reduced portion that is tapered in the distal direction, and the distal diameter-reduced portion has a plurality of irrigation openings for irrigating liquid on the surface of the distal electrode. Arranged,
A plurality of inclined lumens extending in the distal direction while being inclined radially outward of the catheter shaft and reaching each of the irrigation openings are formed inside the reduced diameter portion of the catheter shaft. Electrode catheter.
The ratio (D 2 / D 1 ) of the diameter (D 2 ) of the spherical portion of the tip electrode to the outer diameter (D 1 ) of the catheter shaft is 1.0 to 1.2;
The distance in the axial direction from the rear end of the reduced diameter portion of the catheter shaft to the distal end edge of the irrigation opening (L 1 ), and the shaft from the distal end edge of the irrigation opening to the maximum diameter portion of the distal electrode When the axial distance is (L 2 ), the inclination angle at the reduced diameter portion of the catheter shaft is (β), and the inclination angle of the inclined lumen is (α),
Formula: 0.8D 2 ≦ D 1 +2 (L 2 tan α−L 1 tan β) ≦ 1.2 D 2
The electrode catheter according to claim 1, wherein:
The diameter (D 1 ) of the catheter shaft is 1.0 to 3.0 mm,
The distance (L 1 ) is 0.5 to 5.0 mm,
The distance (L 2 ) is 1.5 to 7.0 mm,
The inclination angle (β) is 5.0 to 30.0 °,
The electrode catheter according to claim 2, wherein the inclination angle (α) is 5.0 to 30.0 °.
The ratio (D 2 / D 1 ) of the diameter (D 2 ) of the spherical portion of the tip electrode to the outer diameter (D 1 ) of the catheter shaft is 1.0 to 1.2;
The distal diameter of the distal end of the irrigation opening or the outer diameter of the distal electrode is (D 3 ), and the distance in the shaft axial direction from the distal edge of the irrigation opening to the maximum diameter of the distal electrode is ( L 2 ), when the inclination angle of the inclined lumen is (α),
Formula: 0.8D 2 ≦ D 3 +2 (L 2 · tan α) ≦ 1.2D 2
The electrode catheter according to claim 1, wherein:
The electrode catheter according to any one of claims 1 to 4, wherein a temperature sensor is attached to the distal end side of the irrigation opening.
The catheter shaft is a multi-lumen structure having a central lumen and a plurality of sub-lumens arranged at equiangular intervals around the central lumen;
Among the plurality of sub-lumens, two sub-lumens arranged opposite to each other are inserted with a pull wire for deflection operation of the shaft tip, and the other sub-lumens constitute a lumen serving as a liquid flow path. ,
The electrode catheter according to any one of claims 1 to 5, wherein the inclined lumen is formed so as to communicate with each of the lumens serving as the liquid flow paths.