JP7853315B2 - Extension guide catheter - Google Patents

Description

The present invention relates to an extension guide catheter for a guide catheter, and more particularly to an extension guide catheter that is inserted into a guide catheter and extended from the distal opening of the guide catheter.

For ischemic heart diseases such as angina pectoris and myocardial infarction, percutaneous coronary intervention (PCI) is performed to widen narrowed coronary arteries and increase blood flow using endovascular devices such as stents and balloons. In this procedure, it is common practice to insert the tip of a tubular guide catheter into the coronary artery opening and then deliver the endovascular device through the guide catheter to improve the insertion of the device into the distal coronary artery. However, if the backup force is insufficient and the above placement is unstable, the tip of the guide catheter may detach from the coronary artery opening. In such cases, a smaller diameter extension guide catheter may be inserted into the guide catheter, extending it from the distal opening of the guide catheter to improve the backup force.

Various types of extension guide catheters are known. For example, Patent Document 1 discloses a guide extension guide catheter having a proximal member including an extension portion, a collar member attached to the extension portion, and a distal sheath member attached to the collar member. Patent Document 2 discloses a guide extension catheter comprising a push member including a portion having a first surface with a groove formed thereon and a second surface on the opposite side, and a distal shaft having a passage adjacent to the push member. Patent Document 3 discloses an extension catheter comprising a cylindrical portion, a first tapered portion located proximal to the cylindrical portion, and a second tapered portion located proximal to the first tapered portion, wherein the angle between the first tapered surface of the first tapered portion and the axial direction of the cylindrical portion is 90° to 145°, and the angle between the second tapered surface of the second tapered portion and the axial direction of the cylindrical portion is 120° to 175°.

International Publication No. 2018/075700 International Publication No. 2017/214209 International Publication No. 2020/162286

An extension guide catheter is used by being inserted into a guide catheter. However, when advancing treatment devices such as intravascular treatment instruments from the guide catheter through the extension guide catheter, the extension guide catheter may be located in a body cavity or a bent portion of the guide catheter. In this case, there is a concern that it may become difficult to insert treatment devices such as intravascular treatment instruments into the extension guide catheter in the body cavity or the bent portion of the guide catheter. The present invention has been made in view of the above circumstances, and its object is to provide an extension guide catheter that facilitates the insertion of treatment devices such as intravascular treatment instruments.

The extension guide catheter of the present invention is as follows:
[1] An extension guide catheter for a guide catheter, comprising: a cylindrical body having a lumen extending in the longitudinal direction and having a proximal opening and a distal opening; and a linear member fixed to the cylindrical body and extending proximal to the proximal opening of the cylindrical body, wherein the cylindrical body has an upper side to which the linear member is fixed and a lower side opposite to the upper side with respect to the radial direction; the proximal opening has a first section, a second section more proximal to the first section and a third section more proximal to the second section with respect to the longitudinal direction; and when viewed from below, the proximal opening is formed such that the width gradually increases from distal to proximal in the first section, the width gradually decreases from distal to proximal in the second section, and the width gradually increases from distal to proximal in the third section.

As described above, the extension guide catheter of the present invention has a first section, a second section, and a third section formed in the proximal opening. Therefore, when the proximal end of the tubular body is located in a body cavity or a bent portion of the guide catheter, and a bending force is applied to the proximal end of the tubular body, the tubular body deforms so that the proximal opening opens when viewed from below, and the size of the proximal opening widens. Furthermore, even if the proximal end of the tubular body is bent, distortion is less likely to occur in that portion, preventing the lumen of the tubular body from collapsing or the cross-sectional shape of the lumen from becoming distorted and the cross-sectional area from narrowing significantly. As a result, it becomes easier to insert a treatment device into the lumen of the tubular body through the proximal opening.

[2] The extension guide catheter according to [1], wherein the outer edge of the proximal opening is formed in the lower half of the tubular body from the distal end of the first section to the proximal end of the second section.
[3] The extension guide catheter according to [1] or [2], wherein the longitudinal length from the distal end of the first section to the proximal end of the second section is 0.3 times or more and 15 times or less the width of the proximal opening at the proximal end of the third section.
[4] The extension guide catheter according to any one of [1] to [3], wherein the width of the proximal opening at the distal end of the third section is 0.3 times or more and 0.9 times or less the width of the proximal opening at the proximal end of the third section.
[5] An extension guide catheter according to any one of [1] to [4], wherein the length in the longitudinal direction of the first section and/or the length in the longitudinal direction of the second section is less than or equal to the length in the longitudinal direction of the third section.
[6] An extension guide catheter according to any of [1] to [5] that satisfies either or both of the following formulas (1) and (2).
(A1-A2)/B1≧(A3-A2)/B3...(1)
(A1-A2)/B2≧(A3-A2)/B3...(2)
[In the above formula, A1 represents the width of the proximal opening at the proximal end of the first section, A2 represents the width of the proximal opening at the proximal end of the second section, A3 represents the width of the proximal opening at the proximal end of the third section, B1 represents the length in the longitudinal direction from the proximal end of the first section to the point in the first section where the width of the proximal opening is A2, B2 represents the length in the longitudinal direction of the second section, and B3 represents the length in the longitudinal direction of the third section.]
[7] An extension guide catheter according to any one of [1] to [6], wherein the distal end of the linear member is located distal to the distal end of the proximal opening.

In the extension guide catheter according to the embodiment of the present invention, when the proximal end of the tubular body is positioned at a bent portion of a body cavity such as a blood vessel or at a bent portion of the guide catheter, the tubular body deforms so that the proximal opening opens when viewed from below, and the size of the proximal opening widens. Furthermore, even when the proximal end of the tubular body is bent, distortion is less likely to occur at that portion, preventing the lumen of the tubular body from collapsing or the cross-sectional shape of the lumen from becoming distorted and the cross-sectional area from narrowing significantly. As a result, it becomes easier to insert a treatment device into the lumen of the tubular body through the proximal opening.

This diagram shows an extension guide catheter according to an embodiment of the present invention, and represents an overall view of the extension guide catheter. Figure 1 shows a side view of the proximal end of the tubular body of the extension guide catheter. Figure 2 shows a view of the proximal end of the tubular body of the extension guide catheter, as seen from below. Figure 3 shows a magnified view of the proximal end of the tubular body of the extension guide catheter. Figure 2 shows a side view of the proximal end of the tubular body of the extension guide catheter, with the proximal end of the tubular body bent. This figure shows an extension guide catheter according to an embodiment of the present invention, inserted into a guide catheter placed in a blood vessel, and extending from the distal opening of the guide catheter. This shows a side view of the proximal end of the tubular body of the extension guide catheter in the comparative configuration. Figure 7 shows a side view of the proximal end of the tubular body of the extension guide catheter, with the proximal end of the tubular body bent.

The extension guide catheter of the present invention will be described in detail below based on the embodiments described below. However, the present invention is not limited by the embodiments described below, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component reference numerals may be omitted in the drawings for convenience, in which case refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping to understand the features of the present invention.

An extension guide catheter according to an embodiment of the present invention will be described with reference to Figures 1 to 6. Figure 1 is an extension guide catheter according to an embodiment of the present invention, showing an overall view of the extension guide catheter; Figure 2 is a side view of the proximal end of the tubular body of the extension guide catheter shown in Figure 1; Figure 3 is a view of the proximal end of the tubular body of the extension guide catheter shown in Figure 2, viewed from below; Figure 4 is an enlarged view of the proximal end of the tubular body of the extension guide catheter shown in Figure 3; Figure 5 is a side view of the proximal end of the tubular body of the extension guide catheter shown in Figure 2, showing the proximal end of the tubular body in a bent state; and Figure 6 is a diagram showing the extension guide catheter according to an embodiment of the present invention inserted into a guide catheter placed in a blood vessel, extending from the distal opening of the guide catheter.

An extension guide catheter is used in combination with a guide catheter. Specifically, it is inserted into the guide catheter and extended from the distal opening of the guide catheter. By using an extension guide catheter, treatment devices such as endovascular treatment instruments can be delivered more stably to the distal end of the vascular system. Examples of endovascular treatment instruments include stents and balloons.

As shown in Figures 1 and 2, the extension guide catheter 1 according to an embodiment of the present invention comprises a cylindrical body 2 having a lumen 4 extending in the longitudinal axis direction x, and a linear member 13 fixed to the cylindrical body 2 and extending proximal to the proximal opening 5 of the cylindrical body 2.

As shown in Figure 6, the extension guide catheter 1 is inserted into the guide catheter 21, which is already placed in the body cavity, during the procedure. Specifically, the extension guide catheter 1 is inserted into the guide catheter 21 through its proximal opening, and then extended distally through the distal opening 22 of the guide catheter 21. Figure 6 shows the extension guide catheter 1 positioned within the guide catheter 21, which is placed in the ascending aorta, with the extension guide catheter 1 extending from the distal opening 22 of the guide catheter 21.

The extension guide catheter 1 allows the tubular body 2 to be advanced or retracted within the guide catheter 21 by pushing or pulling the linear member 13, extending distally from the distal opening 22 of the guide catheter 21, or being retracted into the guide catheter 21. By sending treatment devices such as intravascular treatment instruments through the guide catheter 21 and the extension guide catheter 1, the treatment devices can be reached further into the body cavity. The inner diameter of the guide catheter 21 is larger than the outer diameter of the extension guide catheter 1 in order to accommodate the extension guide catheter 1. The treatment device can be extended distally from the distal opening 6 of the tubular body 2 of the extension guide catheter 1 by entering the guide catheter 21 through the proximal opening and passing through the guide catheter 21, and then entering the extension guide catheter 1 through the proximal opening 5 and passing through the extension guide catheter 1.

In the extension guide catheter 1, the longitudinal axis x is defined as the direction of extension of the extension guide catheter 1, specifically the direction of extension of the tubular body 2 and the linear member 13. The extension guide catheter 1 has a proximal side and a distal side, with respect to the longitudinal axis x. In the extension guide catheter 1, the proximal side refers to the direction toward the user, i.e., the operator's proximal side, with respect to the direction of extension of the extension guide catheter 1, and the distal side refers to the opposite direction of the proximal side, i.e., the direction toward the treatment target. The tubular body 2 has a radial direction, which is perpendicular to the longitudinal axis x.

The length x in the longitudinal axis direction of the extension guide catheter 1 is preferably 800 mm or more, more preferably 1000 mm or more, even more preferably 1200 mm or more, preferably 2200 mm or less, more preferably 2000 mm or less, and even more preferably 1800 mm or less. The length x in the longitudinal axis direction of the cylindrical body 2 is preferably 100 mm or more, more preferably 200 mm or more, even more preferably 250 mm or more, preferably 600 mm or less, more preferably 500 mm or less, and even more preferably 450 mm or less.

From the viewpoint of ensuring the passability of the extension guide catheter 1 within the guide catheter and the passability of the treatment device within the extension guide catheter 1, the diameter of the lumen 4 of the tubular body 2 is preferably 1.0 mm or more, more preferably 1.2 mm or more, even more preferably 1.3 mm or more, preferably 2.2 mm or less, more preferably 2.0 mm or less, and even more preferably 1.9 mm or less. The outer diameter of the tubular body 2 is preferably 1.2 mm or more, more preferably 1.3 mm or more, even more preferably 1.4 mm or more, preferably 3.5 mm or less, more preferably 3.0 mm or less, and even more preferably 2.5 mm or less. The wall thickness of the tubular body 2 is preferably 0.01 mm or more, more preferably 0.02 mm or more, even more preferably 0.05 mm or more, preferably 0.4 mm or less, more preferably 0.3 mm or less, and even more preferably 0.2 mm or less.

In a cross-section perpendicular to the longitudinal axis x of the cylindrical body 2, the shape of the lumen 4 of the cylindrical body 2 and the shape of the outer edge of the cylindrical body 2 are not particularly limited and can be circular, elliptical, oblong, polygonal, irregular, etc. If the shape of the lumen 4 of the cylindrical body 2 or the shape of the outer edge of the cylindrical body 2 is other than circular, the diameter of the lumen 4 of the cylindrical body 2 and the outer diameter of the cylindrical body 2 described above mean the equivalent diameter of a circle. That is, it means the diameter of a circle with a circumference of the same length as the circumference of the lumen 4 of the cylindrical body 2 or the circumference of the outer edge of the cylindrical body 2. The shape of the lumen 4 of the cylindrical body 2 and the shape of the outer edge of the cylindrical body 2 are preferably circular or elliptical, and in the case of an ellipse, the ratio of the minor axis to the major axis is preferably 0.80 or more, more preferably 0.90 or more, and even more preferably 0.95 or more.

The cylindrical body 2 can be made of, for example, a resin. Examples of resins include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluoropolymer resins, vinyl chloride resins, silicone resins, and natural rubber. Examples of polyamide resins include nylon 12, nylon 12 elastomer, nylon 6, and aromatic polyamides. Examples of polyester resins include polyethylene terephthalate. Examples of polyurethane resins include aliphatic polyurethanes containing aliphatic isocyanates as monomer units, and aromatic polyurethanes containing aromatic isocyanates as monomer units. Examples of polyolefin resins include polyethylene and polypropylene. Examples of fluoropolymer resins include polytetrafluoroethylene, ethylenetetrafluoroethylene, and fluorinated ethylene propylene. Examples of vinyl chloride resins include polyvinyl chloride and polyvinylidene chloride. Examples of silicone resins include dimethylpolysiloxane, methylphenylpolysiloxane, methylvinylpolysiloxane, and fluoroalkylmethylpolysiloxane. Examples of natural rubber include latex.

The cylindrical body 2 may be composed of a single layer or multiple layers. Furthermore, in the longitudinal axis direction x, a portion of the cylindrical body 2 may be composed of a single layer, while other portions are composed of multiple layers.

The cylindrical body 2 preferably has a reinforcing layer. The reinforcing layer can increase the rigidity of the cylindrical body 2. The reinforcing layer may be provided on the inner surface of the cylindrical body 2, on the outer surface, or between the inner and outer surfaces of the cylindrical body 2.

The reinforcing layer can be made of metal wires or fibers. Examples of materials for the metal wires include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy. Stainless steel is preferred among these. The metal wire may be a single wire or a stranded wire. Examples of fibers include polyarylate fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, PBO (poly(p-phenylenebenzoxazole)) fibers, and carbon fibers. The fibers may be monofilaments or multifilaments.

The shape of the reinforcing layer is not particularly limited, but helical, mesh-like, and braided shapes are preferred. Among these, a braided shape is more preferred because it effectively increases the rigidity of the cylindrical body 2.

The cylindrical body 2 may contain a radiopaque material to facilitate its position under X-ray fluoroscopy. Examples of radiopaque materials include lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, and tantalum. For example, it is preferable to provide radiopaque markers at the proximal and distal ends of the cylindrical body 2, thereby allowing the position of the cylindrical body 2 within the body cavity to be confirmed under X-ray fluoroscopy.

The cylindrical body 2 may have its outer surface coated with a hydrophilic polymer. This facilitates the insertion of the cylindrical body 2 into a guide catheter or blood vessel. Examples of hydrophilic polymers include poly-2-hydroxyethyl methacrylate, polyacrylamide, polyvinylpyrrolidone, and maleic anhydride copolymers such as methyl vinyl ether maleic anhydride copolymer.

The cylindrical body 2 preferably has an inner layer and an outer layer. The inner layer and outer layer can be made of the resins described above. In particular, the inner layer is preferably made of at least one selected from the group consisting of polyester resin, polyolefin resin, fluororesin, silicone resin, and natural rubber. In particular, the inner layer is preferably made of a fluororesin because it has excellent chemical resistance, non-stick properties, and low friction. The outer layer is preferably made of at least one resin selected from the group consisting of polyamide resin, polyurethane resin, and polyolefin resin, more preferably made of at least one resin selected from the group consisting of polyamide resin and polyurethane resin, and even more preferably made of polyurethane resin.

The cylindrical body 2 preferably has a reinforcing layer in addition to the inner layer and outer layer. The reinforcing layer may be provided on the outer layer, on the inner layer, or between the inner and outer layers, but it is preferable that the reinforcing layer be provided between the inner and outer layers because it is easy to increase the strength of the cylindrical body 2.

The linear member 13 is a long wire and is fixed to the proximal end of the cylindrical body 2. By pushing or pulling the linear member 13, the cylindrical body 2 can be moved forward or backward, thereby allowing the cylindrical body 2 to protrude from the distal opening of the guide catheter or to be pulled back into the guide catheter.

The linear member 13 is preferably made of metal. Examples of metals that make up the linear member 13 include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, tungsten alloy, etc., with stainless steel being more preferred. The cross-sectional shape of the linear member 13 in the direction perpendicular to the longitudinal axis x is not particularly limited, and examples include squares, rectangles, trapezoids and other quadrilaterals, polygons other than quadrilaterals, circles, ellipses, oblongs, etc. Among these, the cross-sectional shape of the linear member 13 is preferably quadrilateral.

Preferably, the extension guide catheter 1 is provided with a gripping member 14 at the proximal end of the linear member 13. By grasping the gripping member 14 with their fingers, the practitioner can easily push or pull the extension guide catheter 1. The material constituting the gripping member 14 is resin, and examples of resins include polyolefin resins such as polyethylene and polypropylene.

The linear member 13 may be fixed to the inner surface of the cylindrical body 2, to the outer surface of the cylindrical body 2, or between the inner and outer surfaces of the cylindrical body 2. If the cylindrical body 2 has an inner layer and an outer layer, the linear member 13 may be fixed to the inner layer of the cylindrical body 2, to the outer layer, or between the inner and outer layers. The linear member 13 is fixed to one side of the cylindrical body 2 in the radial direction, and the cylindrical body 2 is defined as having an upper side on which the linear member 13 is fixed and a lower side on the opposite side in the radial direction. That is, the cylindrical body 2 has an upper side on which the linear member 13 is fixed and a lower side on the opposite side in the radial direction. Furthermore, the direction extending from the upper side to the lower side in the radial direction is called the vertical direction, and the direction perpendicular to it is called the width direction.

The cylindrical body 2 has a proximal opening 5 and a distal opening 6. The proximal opening 5 of the cylindrical body 2 refers to the proximal opening of the lumen 4 of the cylindrical body 2, and the distal opening 6 of the cylindrical body 2 refers to the distal opening of the lumen 4 of the cylindrical body 2. The proximal opening 5 of the cylindrical body 2 has a portion that is inclined with respect to the longitudinal axis x. The cylindrical body 2 has a cylindrical portion 3 formed in a cylindrical shape and a non-cylindrical proximal extension portion 11 that extends proximal to the cylindrical portion 3, and the outer edge of the proximal opening 5 is formed in the proximal extension portion 11. The lumen 4 of the cylindrical body 2 is formed in the cylindrical portion 3.

The proximal opening 5 has a first section 7, a second section 8 more proximal to the first section 7, and a third section 9 more proximal to the second section 8, with respect to the longitudinal axis x. In the cylindrical body 2, the proximal extension portion 11 where the outer edge of the proximal opening 5 is formed, specifically the portion of the proximal extension portion 11 in the longitudinal axis x range where the first section 7 to the third section 9 are formed, and the portion adjacent to it distally, are referred to as the proximal end of the cylindrical body 2. For example, the portion of the proximal extension portion 11 in which the first section 7 to the third section 9 are formed, and the portion within 20 mm distal to the proximal end of the adjacent cylindrical portion 3, can be considered the proximal end of the cylindrical body 2. Also, in the proximal extension portion 11, the portion in the longitudinal axis x range where the first section 7 is formed is referred to as the first section 7 of the proximal extension portion 11. Similarly, for the portion of the proximal extension 11 that is more proximal to the first section 7, a portion in the longitudinal direction x is defined based on each section.

As shown in Figure 3, when viewed from below, the proximal opening 5 of the cylindrical body 2 is formed such that its width gradually increases from distal to proximal in the first section 7, gradually decreases from distal to proximal in the second section 8, and gradually increases from distal to proximal in the third section 9. In the extension guide catheter 1 according to the embodiment of the present invention, the proximal opening 5 of the cylindrical body 2 is formed in this way, so that when the proximal end of the cylindrical body 2 is located in a curved portion of a body cavity such as a blood vessel or a curved portion of the guide catheter, the cylindrical body 2 deforms so that the size of the proximal opening 5 expands, making it easy to insert a treatment device such as an intravascular treatment instrument into the lumen 4 of the cylindrical body 2 through the proximal opening 5 of the cylindrical body 2.

To explain this in more detail, the extension guide catheter 1 is used by being inserted into the body cavity along with the guide catheter. However, when the extension guide catheter 1 is set to a desired position within the body cavity to deliver the treatment device from the guide catheter through the extension guide catheter 1, the proximal end of the cylindrical body 2 may be located in a curved portion of the body cavity or the guide catheter. In this case, the proximal end of the cylindrical body 2 bends along the curved portion of the body cavity or the guide catheter, with the lower side of the cylindrical body 2 facing inward. This raises concerns that the lumen 4 of the cylindrical body 2 may collapse or the cross-sectional shape of the lumen 4 may be distorted, narrowing the cross-sectional area. However, as described above, the extension guide catheter 1 has a first section 7, a second section 8, and a third section 9 formed in the proximal opening 5. Therefore, when the proximal end of the cylindrical body 2 is located in a curved portion of the body cavity or the guide catheter, and a bending force is applied to the proximal end of the cylindrical body 2, the cylindrical body 2 deforms so that the proximal opening 5 opens when viewed from below, and the size of the proximal opening 5 widens. Furthermore, even if the proximal end of the cylindrical body 2 is bent, distortion is less likely to occur in that portion, preventing the lumen 4 of the cylindrical body 2 from collapsing or the cross-sectional shape of the lumen 4 from becoming distorted and significantly narrowing its cross-sectional area. As a result, it becomes easier to insert the treatment device into the lumen 4 of the cylindrical body 2 through the proximal opening 5 of the cylindrical body 2.

For example, as shown in Figure 7, if the outer edge of the proximal opening 5 is formed to extend simply diagonally with respect to the longitudinal axis x, when the proximal end of the cylindrical body 2 bends, distortion occurs at the distal end of the proximal opening 5, as shown in Figure 8, making it prone to bending inward in an irregular shape. As a result, distortion occurs in the lower part of the lumen 4 of the cylindrical body 2, narrowing the cross-sectional area of the lumen 4, which may hinder the insertion of a treatment device into the proximal opening 5 of the cylindrical body 2. In contrast, if the proximal opening 5 is provided with a first section 7, a second section 8, and a third section 9, when a bending force is applied to the third section 9 of the proximal extension portion 11, that force is transmitted to the second section 8, and as shown in Figure 5, the lower part of the proximal opening 5 can be deformed to open in the second section 8. Furthermore, the proximal extension portion 11 can be easily bent from the first section 7 to the second section 8, and in conjunction with this bending, it can deform so that the lower part of the proximal opening 5 opens from the second section 8 to the third section 9. Moreover, even when the proximal extension portion 11 is bent from the first section 7 to the second section 8, distortion is less likely to occur in that portion, and the proximal end of the cylindrical body 2 can be bent with a larger curvature. And because the proximal opening 5 is formed to be wide from the first section 7 to the second section 8, a large opening is formed on the lower side of the cylindrical body 2 by deforming so that the lower part of the proximal opening 5 opens from the second section 8 to the third section 9. As a result, when inserting a treatment device through the proximal opening 5 of the cylindrical body 2, the treatment device is less likely to get caught on the outer edge of the proximal opening 5 of the cylindrical body 2, making it easier to insert the treatment device into the proximal opening 5 of the cylindrical body 2.

The width of the proximal opening 5 is determined based on the projected shape of the outer edge of the proximal opening 5 when the cylindrical body 2 is viewed from below. It is determined by measuring the length between the two ends of the outer edge of the proximal opening 5 in the direction perpendicular to the longitudinal axis x and the vertical direction, i.e., the width direction. The outer edge of the proximal opening 5 may be formed in a straight line, a curved shape, or a combination of these shapes when viewed from below the cylindrical body 2.

In the first section 7 to the third section 9, it is preferable that the outer edge of the proximal opening 5 is formed symmetrically in the width direction. In this case, the width of the proximal opening 5 can be determined by measuring the length in the width direction between the two ends of the outer edge of the proximal opening 5 at the same position in the vertical direction in a vertical cross-section of the proximal opening 5 along the longitudinal axis x. When the proximal end of the cylindrical body 2 is located in a body cavity or a bent portion of a guide catheter, the proximal end of the cylindrical body 2 can bend smoothly without causing significant distortion. Furthermore, when the proximal end of the cylindrical body 2 is bent, the proximal opening 5 tends to widen in the width direction approximately equally on one side and the other side. Note that forming symmetrically in the width direction means forming symmetrically with respect to a plane defined by the longitudinal axis x and the vertical direction.

The proximal opening 5 is preferably formed such that the distal end of the first section 7 is the distal end of the proximal opening 5. Therefore, it is preferable that the first section 7 is formed to include the distal end of the proximal opening 5. On the other hand, the proximal opening 5 may also exist proximal to the proximal end of the third section 9, for example, it may have a fourth section 10 proximal to the third section 9, formed such that its width gradually decreases from the distal to the proximal side.

Preferably, the outer edge of the proximal opening 5 is formed on the lower half of the tubular body 2, from the distal end of the first section 7 to the proximal end of the second section 8. This prevents the proximal extension 11 from bending excessively from the first section 7 to the second section 8 when the proximal end of the tubular body 2 is located in a body cavity or a curved portion of a guide catheter. Therefore, when inserting a treatment device through the proximal opening 5, it is possible to prevent the treatment device from getting caught on the outer edge of the proximal opening 5. In addition, a bending force is more easily applied to the third section 9 of the proximal extension 11, and this force is transmitted to the second section 8, making it easier for the lower part of the proximal opening 5 to deform and open in the second section 8. Alternatively, as the proximal extension 11 bends from the first section 7 to the second section 8, it becomes easier for the lower part of the proximal opening 5 to deform and open from the second section 8 to the third section 9.

The outer edge of the proximal opening 5 is preferably formed on the lower half of the cylindrical body 2, even in the third section 9. Therefore, the outer edge of the proximal opening 5 is preferably formed on the lower half of the cylindrical body 2, from the first section 7 to the third section 9. In this case, the proximal end of the third section 9 is preferably coincided with the proximal end of the lower half of the cylindrical body 2. Furthermore, in the fourth section 10, which is proximal to the third section 9, the outer edge of the proximal opening 5 is preferably formed on the upper half of the cylindrical body 2.

The length x in the longitudinal axis direction from the distal end of the first section 7 to the proximal end of the second section 8 is preferably 0.3 times or more, more preferably 0.6 times or more, and even more preferably 1 time or more, the width of the proximal opening 5 at the proximal end of the third section 9. This makes it easier for the lower part of the proximal opening 5 to deform smoothly and widen when the proximal end of the cylindrical body 2 is bent. Also, when the lower part of the proximal opening 5 opens, the treatment device is less likely to get caught on the outer edge of the proximal opening 5 of the cylindrical body 2, especially the protruding part of the proximal extension portion 11 from the second section 8 to the third section 9. On the other hand, the length x in the longitudinal axis direction from the distal end of the first section 7 to the proximal end of the second section 8 is preferably 15 times or less, more preferably 12 times or less, and even more preferably 10 times or less, the width of the proximal opening 5 at the proximal end of the third section 9. As a result, the length x in the longitudinal axis direction of the first section 7 and the second section 8 of the proximal extension portion 11 is not formed to be excessively long, and when the proximal end of the tubular body 2 is located in a body cavity or a bent portion of the guide catheter, a bending force is more easily applied to the third section 9 of the proximal extension portion 11. Therefore, the force applied to the third section 9 of the proximal extension portion 11 is transmitted to the second section 8, making it easier for the second section 8 to deform so that the lower part of the proximal opening 5 opens.

The length of the longitudinal axis x of the first section 7 and/or the length of the longitudinal axis x of the second section 8 is preferably less than or equal to the length of the longitudinal axis x of the third section 9. If the proximal opening 5 is formed in this manner, when the proximal extension portion 11 bends from the first section 7 to the second section 8, distortion is less likely to occur in that portion. Therefore, when inserting the treatment device from the proximal opening 5 of the cylindrical body 2, the treatment device is less likely to get caught on the outer edge of the proximal opening 5 of the cylindrical body 2. In this case, either the length of the longitudinal axis x of the first section 7 or the length of the longitudinal axis x of the second section 8 may be longer than the length of the longitudinal axis x of the third section 9, but in that case, it is preferably 2.0 times or less, and more preferably 1.5 times or less, the length of the longitudinal axis x of the third section 9. Also, both the length of the longitudinal axis x of the first section 7 and the length of the longitudinal axis x of the second section 8 may be less than or equal to the length of the longitudinal axis x of the third section 9.

The width of the proximal opening 5 at the distal end of the third section 9 is preferably 0.3 times or more, more preferably 0.4 times or more, and even more preferably 0.5 times or more than the width of the proximal opening 5 at the proximal end of the third section 9. When the proximal opening 5 is formed in this way, when inserting the treatment device from the proximal opening 5 of the cylindrical body 2, the treatment device is less likely to get caught on the protruding portion of the proximal extension 11 from the second section 8 to the third section 9. On the other hand, the width of the proximal opening 5 at the distal end of the third section 9 is preferably 0.9 times or less the width of the proximal opening 5 at the proximal end of the third section 9, thereby ensuring the length x in the longitudinal axis direction of the third section 9. Therefore, when the proximal end of the cylindrical body 2 is located in a body cavity or a bent portion of a guide catheter, the force applied to the third section 9 of the proximal extension 11 is transmitted to the second section 8, making it easier for the lower part of the proximal opening 5 to deform and open in the second section 8.

The width of the proximal opening 5 at the distal end of the second section 8 is preferably 0.4 to 1.0 times the width of the proximal opening 5 at the proximal end of the third section 9, more preferably 0.5 times or more, and even more preferably 0.6 times or more. This allows the proximal opening 5 to widen into a large opening in the lower part when a bending force is applied to the proximal end of the cylindrical body 2, making it easier to insert the treatment device through the proximal opening 5 of the cylindrical body 2. In addition, the proximal extension portion 11 can bend smoothly from the first section 7 to the second section 8.

It is preferable that the first section 7, the second section 8, and the third section 9 are formed to satisfy one or both of the following formulas (1) and (2).
(A1-A2)/B1≧(A3-A2)/B3...(1)
(A1-A2)/B2≧(A3-A2)/B3...(2)

In the above formula, A1 to A3 and B1 to B3 represent the lengths of the respective parts shown in Figure 4. Specifically, A1 represents the width of the proximal opening 5 at the proximal end of the first section 7, A2 represents the width of the proximal opening 5 at the proximal end of the second section 8, A3 represents the width of the proximal opening 5 at the proximal end of the third section 9, B1 represents the length x in the longitudinal direction from the proximal end of the first section 7 to the point in the first section 7 where the width of the proximal opening 5 is A2, B2 represents the length x in the longitudinal direction of the second section 8, and B3 represents the length x in the longitudinal direction of the third section 9.

If the proximal opening 5 is formed in this manner, the proximal extension portion 11 can bend smoothly from the first section 7 to the second section 8, making it easier to bend the proximal end of the cylindrical body 2 significantly. The first section 7, the second section 8, and the third section 9 are preferably formed to satisfy at least one of the above formulas (1) and (2), but more preferably they are formed to satisfy both the above formulas (1) and (2).

When viewed from below, the outer edge of the proximal opening 5 preferably extends in the second section 8 and the third section 9 such that the angle it makes with the longitudinal axis direction x is 60° or less, more preferably 50° or less, and even more preferably 45° or less. For the first section 7, in the proximal 1/2 range, preferably the proximal 2/3 range, the outer edge of the proximal opening 5 preferably extends so that the angle it makes with the longitudinal axis direction x is 60° or less, more preferably 50° or less, and even more preferably 45° or less. If the outer edge of the proximal opening 5 is formed in this way, when the treatment device is inserted into the proximal opening 5 of the cylindrical body 2, the treatment device is less likely to get caught on the outer edge of the proximal opening 5.

The outer edge of the proximal opening 5 may have a portion extending parallel to the longitudinal axis x between the first section 7 and the second section 8 and/or between the second section 8 and the third section 9. That is, the proximal opening 5 may have a portion extending between the first section 7 and the second section 8 and/or between the second section 8 and the third section 9 such that its width does not change from the distal side to the proximal side. The length of the portion of the proximal opening 5 that extends in the longitudinal axis x with a constant width is preferably 1/3 or less, and more preferably 1/4 or less, of the length in the longitudinal axis x from the distal end of the first section 7 to the proximal end of the third section 9. This makes it easier for the proximal end of the cylindrical body 2 to bend smoothly along the bent portion when it is located in a body cavity or a bent portion of a guide catheter. The outer edge of the proximal opening 5 may also have a portion that extends parallel to the longitudinal axis x between the third section 9 and the fourth section 10. In this case, the length of the portion of the proximal opening 5 that extends in the longitudinal axis x with a constant width is preferably 1/3 or less, and more preferably 1/4 or less, of the length in the longitudinal axis x from the distal end of the first section 7 to the proximal end of the fourth section 10.

It is preferable that the linear member 13 is fixed to the cylindrical body 2 at the proximal extension portion 11. It is also preferable that the linear member 13 extends distally beyond the distal end of the proximal opening 5. Therefore, it is preferable that the distal end of the linear member 13 is located distal to the distal end of the proximal opening 5. By providing the linear member 13 in this way, the cylindrical body 2 becomes easier to bend smoothly from the cylindrical portion 3 to the first section 7, the second section 8, and the third section 9. It is also preferable that the linear member 13 is fixed to the cylindrical body 2 distal to the distal end of the proximal opening 5. By fixing the linear member 13 to the cylindrical body 2 in this way, it becomes easier to advance the cylindrical body 2 by pushing in the linear member 13. In addition, the lumen 4 of the cylindrical body 2 becomes less likely to collapse in the body cavity or the bent portion of the guide catheter.

The proximal extension portion 11 is preferably located proximal to the third section 9 or the fourth section 10 and has a strip-shaped portion 12 that extends parallel to the longitudinal axis x. The provision of this strip-shaped portion 12 makes it easier to insert the treatment device along the strip-shaped portion 12 from the proximal opening 5 of the cylindrical body 2.

The strip-shaped portion 12 is formed on the upper part of the cylindrical body 2, and the linear member 13 is preferably arranged along the strip-shaped portion 12 and fixed to the strip-shaped portion 12. The length x in the longitudinal axis direction of the strip-shaped portion 12 is preferably 50 mm or more, more preferably 80 mm or more, even more preferably 100 mm or more, and preferably 200 mm or less, more preferably 180 mm or less, and even more preferably 150 mm or less. This allows the linear member 13 to be stably fixed to the cylindrical body 2.

The cylindrical portion 3 of the cylindrical body 2 has a resin layer and a reinforcing layer in which metal wires or fibers are arranged in a helical, mesh, or braided manner. Preferably, the proximal end of the reinforcing layer is within 15 mm distal to the distal end of the proximal opening 5, more preferably within 10 mm, and even more preferably within 8 mm. By providing the reinforcing layer in this way, the lumen 4 of the cylindrical body 2 becomes less likely to collapse, and it becomes easier to insert the treatment device into the lumen 4 of the cylindrical body 2. Preferably, the resin layer of the cylindrical portion 3 includes the inner layer and outer layer described above.

The proximal extension portion 11 of the tubular body 2 preferably has the inner layer and outer layer described above. It is preferable that the proximal extension portion 11 does not have a reinforcing layer. This allows the proximal extension portion 11 to bend more easily than the tubular portion 3 of the tubular body 2 when the proximal end of the tubular body 2 is located in a curved portion of a body cavity such as a blood vessel or a curved portion of a guide catheter, thereby suppressing excessive distortion of the tubular portion 3 or the formation of kinks in the tubular portion 3.

This application claims the benefit of priority based on Japanese Patent Application No. 2021-169116, filed on 14 October 2021. The entire specification of Japanese Patent Application No. 2021-169116, filed on 14 October 2021, is incorporated herein by reference.

1: Extension guide catheter 2: Tubular body 3: Tubular portion 4: Lumen 5: Proximal opening 6: Distal opening 7: First section 8: Second section 9: Third section 10: Fourth section 11: Proximal extension portion 12: Band-shaped portion 13: Linear member 14: Gripping member 21: Guide catheter

Claims (7)

An extension guide catheter for a guide catheter,
A cylindrical body having a lumen extending in the longitudinal direction and having a proximal opening and a distal opening,
It has a linear member that is fixed to the cylindrical body and extends proximal to the proximal opening of the cylindrical body,
The cylindrical body has an upper side to which the linear member is fixed and a lower side on the opposite side in the radial direction.
The proximal opening has, with respect to the longitudinal axis, a first section, a second section more proximal to the first section, and a third section more proximal to the second section.
An extension guide catheter in which, when viewed from below, the proximal opening of the cylindrical body is formed such that the width gradually increases from distal to proximal in the first section, the width gradually decreases from distal to proximal in the second section, and the width gradually increases from distal to proximal in the third section. The extension guide catheter according to claim 1, wherein, from the distal end of the first section to the proximal end of the second section, the outer edge of the proximal opening is formed in the lower half portion of the cylindrical body. The extension guide catheter according to claim 1, wherein the length in the longitudinal axis direction from the distal end of the first section to the proximal end of the second section is 0.3 times or more and 15 times or less the width of the proximal opening at the proximal end of the third section. The extension guide catheter according to claim 1, wherein the width of the proximal opening at the distal end of the third section is 0.3 times or more and 0.9 times or less the width of the proximal opening at the proximal end of the third section. The extension guide catheter according to claim 1, wherein the length of the first section in the longitudinal direction and/or the length of the second section in the longitudinal direction is less than or equal to the length of the third section in the longitudinal direction. An extension guide catheter according to claim 1, satisfying either or both of the following formulas (1) and (2).
(A1-A2)/B1≧(A3-A2)/B3...(1)
(A1-A2)/B2≧(A3-A2)/B3...(2)
[In the formula,
A1 represents the width of the proximal opening at the proximal end of the first section,
A2 represents the width of the proximal opening at the proximal end of the second section,
A3 represents the width of the proximal opening at the proximal end of the third section,
B1 represents the length in the longitudinal direction from the proximal end of the first section to the point in the first section where the width of the proximal opening is A2.
B2 represents the length of the second section in the longitudinal direction,
B3 represents the length of the third section in the longitudinal direction. The extension guide catheter according to claim 1, wherein the distal end of the linear member is located distal to the distal end of the proximal opening.