JP7853314B2 - 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, and in a plan view formed from the longitudinal direction and the vertical direction of the cylindrical body, the outer edge of the proximal opening has a first section that extends distally from the upper side to the lower side in a region between the upper 1/3 and the lower 1/2 of the cylindrical body, and a second section located distal to the first section and including the distal end of the proximal opening, wherein the first section has a specific inclined portion, and the second section is formed above the tangent to the outer edge in the specific inclined portion.

The extension guide catheter of the present invention has a first section and a second section as described above at the outer edge of the proximal opening of the tubular body. This makes it easier for the tubular body to bend from the first section to the second section when the proximal end of the tubular body is located in a body cavity or a curved portion of the guide catheter, thereby suppressing excessive distortion of the tubular portion of the tubular body and preventing kinking of the tubular portion. The tubular body bends particularly easily in the first section, and when a bending force applied to the first section of the tubular body is transmitted to the second section, the lower part of the proximal opening in the second section deforms to open, widening the size of the proximal opening. As a result, it becomes easier to insert treatment devices such as intravascular treatment instruments into the lumen of the tubular body through the proximal opening of the tubular body.

[2] The extension guide catheter according to [1], wherein the specific inclined portion is formed in a straight line, and the tangent is an extension of the specific inclined portion formed in a straight line.
[3] In the first section, the outer edge of the proximal opening is formed to extend distally in an inclined direction from top to bottom in a region between the upper one-third and lower one-third of the tubular body, as described in [1] or [2].
As described above, the formation of the first section makes it easier for the proximal end of the tubular body to bend preferentially in the first section when it is located in a body cavity or a curved portion of a guide catheter.

[4] The extension guide catheter according to any one of [1] to [3], wherein the second section is formed only in the lower 1/3 region of the tubular body.
[5] The extension guide catheter according to any one of [1] to [4], wherein the width of the proximal opening in the second section when the cylindrical body is viewed from below is 0.05 times or more and 0.9 times or less the outer diameter of the cylindrical body.
[6] An extension guide catheter according to any one of [1] to [5], wherein the length of the second section is 0.3 times or more and 10 times or less the outer diameter of the cylindrical body.
If the second section is formed as described above, when a bending force is applied to the proximal end of the cylindrical body, the cylindrical body will be more likely to deform in the second section such that the lower part of the proximal opening opens.

[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.
As described above, the linear member makes it easier for the cylindrical body to bend smoothly from the cylindrical portion to the first and second sections.

The extension guide catheter of the present invention is designed so that when the proximal end of the tubular body is located in a body cavity or a bent portion of the guide catheter, the tubular body bends easily from the first section to the second section, suppressing significant distortion or kinking of the tubular body. The tubular body bends particularly easily in the first section, and when a bending force applied to the first section of the tubular body is transmitted to the second section, the lower part of the proximal opening in the second section deforms to open, widening the size of the proximal opening. As a result, it becomes easier to insert treatment devices such as intravascular treatment instruments 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 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 an extension guide catheter according to another embodiment of the present invention. This shows a side view of the proximal end of the tubular body of an extension guide catheter according to another embodiment of the present invention. 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 overall view of an extension guide catheter according to an embodiment of the present invention; 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 side view of the proximal end of the tubular body of the extension guide catheter shown in Figure 2, with the proximal end of the tubular body bent; and Figure 4 shows an extension guide catheter according to an embodiment of the present invention inserted into a guide catheter placed in a blood vessel, with the extension guide catheter extending from the distal opening of the guide catheter. Figures 5 and 6 are side views of the proximal end of the tubular body of an extension guide catheter according to another embodiment of the present invention.

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 4, the extension guide catheter 1 is used by inserting it 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 4 shows the extension guide catheter 1 positioned within the guide catheter 21 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 position confirmation 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 confirmation of the position of the cylindrical part 2 within the body cavity 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 7 that extends proximal to the cylindrical portion 3, and the outer edge of the proximal opening 5 is formed in the proximal extension portion 7. The lumen 4 of the cylindrical body 2 is formed in the cylindrical portion 3.

As shown in Figure 2, the outer edge of the proximal opening 5 of the cylindrical body 2 has a first section 8 that extends distally from the top to the bottom in a side view of the cylindrical body 2, i.e., a plan view formed from the longitudinal axis x and the vertical direction of the cylindrical body 2, and a second section 9 located distal to the first section 8 and including the distal end of the proximal opening 5. In the cylindrical body 2, the proximal extension portion 7 on which the outer edge of the proximal opening 5 is formed, specifically the portion of the proximal extension portion 7 on which the first section 8 and the second section 9 are formed, and the portion adjacent to its distal side, are referred to as the proximal end of the cylindrical body 2. For example, the first section 8 and the second section 9 of the proximal extension portion 7, 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.

The first section 8 of the outer edge of the proximal opening 5 is formed to extend distally from the top to the bottom, in a region at least between the upper 1/3 and lower 1/2 of the cylindrical body 2. The first section 8 has a specific inclined portion 10 in the portion formed in this way. The second section 9 is formed above the tangent line 11 of the outer edge of the specific inclined portion 10 of the first section 8. To explain this in more detail, in a side view of the cylindrical body 2, if a tangent line 11 of the outer edge of the proximal opening 5 is drawn at the specific inclined portion 10 of the first section 8, the tangent line 11 becomes a straight line that extends distally from the top to the bottom, and the second section 9 is formed in a region above this straight line. The outer edge of the proximal opening 5 is located above the tangent line 11 at the same position in the longitudinal axis x throughout the entire range of the second section 9. In other words, in the first section 8, when a tangent line 11 is drawn to the outer edge of the proximal opening 5 in a side view of the cylindrical body 2, there is a portion in which it is possible to draw a tangent line 11 such that the entire range of the second section 9 is located above the tangent line 11, and this portion becomes the specific inclined portion 10 of the first section 8.

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 manner, 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 lumen 4 of the cylindrical body 2 is less likely to collapse, and the cylindrical body 2 can deform so that the lower portion of the proximal opening 5 expands. Therefore, it becomes easier 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 guide catheter or body cavity. However, when the treatment device is delivered from the guide catheter through the extension guide catheter 1, the proximal end of the tubular body 2 may be located in a bent portion of the body cavity or guide catheter when the extension guide catheter 1 is set to the desired position in the body cavity. In this case, the proximal end of the tubular body 2 bends along the bent portion of the body cavity or guide catheter, with the lower side of the tubular body 2 facing inward. This raises concerns that the lumen 4 of the tubular body 2 may collapse or the cross-sectional shape of the lumen 4 may be distorted, significantly narrowing the cross-sectional area of the lumen 4. However, the extension guide catheter 1 has a first section 8 and a second section 9 as described above at the outer edge of the proximal opening 5 of the cylindrical body 2. This makes it easier for the cylindrical body 2 to bend from the first section 8 to the second section 9 when the proximal end of the cylindrical body 2 is located in a body cavity or a bent portion of the guide catheter. This prevents the cylindrical portion 3 of the cylindrical body 2 from being greatly distorted or kinked. As a result, the lumen 4 of the cylindrical body 2 is less likely to collapse in the cylindrical portion 3. The cylindrical body 2 bends more easily, especially in the first section 8. When a bending force applied to the first section 8 of the cylindrical body 2 is transmitted to the second section 9, the lower part of the proximal opening 5 in the second section 9 deforms to open, and the size of the proximal opening 5 widens. 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 a second section 9 is not provided in the proximal opening 5, 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, the cross-sectional shape of the lumen 4 of the cylindrical body 2 becomes significantly distorted, especially in the lower part of the lumen 4, narrowing the cross-sectional area of the lumen 4 and potentially hindering the insertion of a treatment device into the proximal opening 5 of the cylindrical body 2. In contrast, as shown in Figure 2, if a second section 9 is provided on the outer edge of the proximal opening 5, when a bending force is applied to the first section 8, that force is transmitted to the second section 9, and as shown in Figure 3, the lower part of the proximal opening 5 can be deformed in the second section 9 to open. Therefore, distortion at the distal end of the proximal opening 5 is suppressed. In addition, the lumen 4 of the cylindrical body 2 does not collapse, making it easier to maintain its initial shape. Furthermore, the proximal end of the cylindrical body 2 deforms in the second section 9 so that the lower part of the proximal opening 5 opens, making it easier to insert the treatment device through the proximal opening 5 of the cylindrical body 2.

As described above, the first section 8 is formed in a side view of the cylindrical body 2, in a region between the upper 1/3 and lower 1/2 of the cylindrical body 2, and extends distally from the top to the bottom. That is, the outer edge of the proximal opening 5 is formed in a side view of the cylindrical body 2, in a region of the upper half of the cylindrical body 2, and in a region below the lower end of the upper 1/3 of the cylindrical body 2, and this portion becomes the first section 8. In the first section 8, the outer edge of the proximal opening 5 may be formed in a straight line extending distally from the top to the bottom, or in a curved shape extending distally from the top to the bottom, or in a combination of these shapes.

In the above case, the specific inclined portion 10 of the first section 8 can be set to at least a part of the outer edge of the proximal opening 5 in the region between the upper 1/3 and lower 1/2 of the cylindrical body 2 when viewed from the side, i.e., the upper half of the cylindrical body 2, and in the region below the lower end of the upper 1/3 region of the cylindrical body 2. Furthermore, even if the first section 8 is also formed in the region above the lower end of the upper 1/3 region of the cylindrical body 2, it is preferable that the specific inclined portion 10 of the first section 8 be set to at least a part of the outer edge of the proximal opening 5 in the region between the upper 1/3 and lower 1/2 of the cylindrical body 2.

Preferably, the first section 8 is formed in a side view of the cylindrical body 2, in a region between the upper 1/3 and lower 1/3 of the cylindrical body 2, and extends distally from the top to the bottom. That is, the outer edge of the proximal opening 5 is formed in a side view of the cylindrical body 2, in a region of at least the middle 1/3 of the cylindrical body 2 in the vertical direction, and it is preferable that this portion becomes the first section 8. With the first section 8 formed in this way, 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 opening 5 is more likely to bend in the first section 8 than in the second section 9. Also, in the second section 9, the cylindrical body 2 is more likely to deform so that the lower portion of the proximal opening 5 opens.

In the above case, the specific inclined portion 10 of the first section 8 is preferably set on at least a part of the outer edge of the proximal opening 5 in the middle 1/3 region of the cylindrical body 2 in the vertical direction, as seen in a side view of the cylindrical body 2, and more preferably set on at least a part of the outer edge of the proximal opening 5 in the region between the upper 1/2 and lower 1/3 of the cylindrical body 2, i.e., the lower half region of the cylindrical body 2, and in the region above the upper end of the lower 1/3 region of the cylindrical body 2. Even if the first section 8 is also formed in the region above the lower end of the upper 1/3 region of the cylindrical body 2, the specific inclined portion 10 of the first section 8 is preferably set on at least a part of the outer edge of the proximal opening 5 in the middle 1/3 region of the cylindrical body 2 in the vertical direction, and more preferably set on at least a part of the outer edge of the proximal opening 5 in the region between the upper 1/2 and lower 1/3 of the cylindrical body 2.

The first section 8 may be formed in a side view of the cylindrical body 2, extending distally from the top to the bottom in a region between at least the upper 1/4 and lower 1/2 of the cylindrical body 2, or in a region between at least the upper 1/4 and lower 1/3 of the cylindrical body 2, or it may be formed extending distally from the top to the bottom in a region between at least the upper 1/6 and lower 1/2 of the cylindrical body 2, or in a region between at least the upper 1/6 and lower 1/3 of the cylindrical body 2. If the first section 8 is formed in this way, a wide opening area of the proximal opening 5 can be secured, making it easier to insert the treatment device through the proximal opening 5 of the cylindrical body 2.

The first section 8 is preferably formed in the region below the upper 1/3 of the cylindrical body 2, and extends distally from the top to the bottom, inclined to form an angle of 10° to 80° with respect to the longitudinal axis x in a side view of the cylindrical body 2. This angle is preferably 12° or more, more preferably 15° or more, preferably 70° or less, more preferably 60° or less, and even more preferably 50° or less. When the first section 8 is formed in this way, the proximal opening 5 is more likely to bend preferentially in the first section 8 when the proximal end of the cylindrical body 2 is located in a body cavity or a bent portion of a guide catheter. In addition, a wider opening area of the proximal opening 5 can be secured, making it easier to insert a treatment device through the proximal opening 5 of the cylindrical body 2. The angle described here refers to the angle between the extending direction of the outer edge of the proximal opening 5 in the first section 8 and the longitudinal axis x in a side view of the cylindrical body 2. The extension direction of the outer edge of the proximal opening 5 in the first section 8 means the extension direction of the straight line if the first section 8 is formed in a straight line, and the extension direction of the tangent to the curve if the first section 8 is formed in a curved line.

Preferably, the first section 8 is formed in a linear shape extending distally from the top to the bottom in the region below the upper 1/3 of the cylindrical body 2, or it is formed to extend distally from the top to the bottom, with the angle with the longitudinal axis x decreasing towards the distal end. If the first section 8 is formed in this way, when the proximal end of the cylindrical body 2 is located in a body cavity or a bent portion of a guide catheter, a bending force applied to the first section 8 will easily transmit that force to the second section 9. As a result, in the second section 9, the cylindrical body 2 is more likely to deform so that the lower part of the proximal opening 5 opens.

Preferably, the first section 8 includes a linearly formed portion that extends distally from the top to the bottom, in a region below the upper one-third of the cylindrical body 2. When the first section 8 is formed in this way, flexibility in the first section 8 is ensured, and when the proximal end of the cylindrical body 2 is located in a curved portion of a body cavity or guide catheter, the proximal opening 5 can bend smoothly along the curved portion. In addition, a portion of the bending force applied to the first section 8 is more easily transmitted to the second section 9, and in the second section 9, the cylindrical body 2 can be more easily deformed so that the lower portion of the proximal opening 5 opens.

In the above case, it is preferable that the linearly formed portion of the first section 8 becomes the specific inclined portion 10. That is, it is preferable that the specific inclined portion 10 is formed in a linear shape. In this case, the extension of the linearly formed specific inclined portion 10 becomes the tangent line 11 of the specific inclined portion 10, and the second section 9 is formed above the extension of the linearly formed specific inclined portion 10.

The linear specific inclined portion 10 is preferably formed including the central position in the vertical direction of the cylindrical body 2. The linear specific inclined portion 10 is also preferably formed in the lower half of the cylindrical body 2, in at least a portion of the area above the upper end of the lower one-third of the cylindrical body 2, and more preferably in the entirety of that portion. The linear specific inclined portion 10 includes the upper half of the cylindrical body 2, in at least a portion of the area below the lower end of the upper one-third of the cylindrical body 2, and the lower half of the cylindrical body 2, in at least a portion of the area above the upper end of the lower one-third of the cylindrical body 2, and may be formed continuously across the central position in the vertical direction of the cylindrical body 2, or may be formed from the lower end of the upper one-third of the cylindrical body 2 to the upper end of the lower one-third of the cylindrical body 2.

The second section 9 is adjacent to the distal side of the first section 8 and includes the distal end of the proximal opening 5. The shape of the outer edge of the proximal opening 5 in the second section 9 is not particularly limited, as long as it is formed above the tangent line 11 of the specific inclined portion 10 of the first section 8. The second section 9 may be formed in a straight line, a curved shape, or a combination of these shapes in a side view of the cylindrical body 2. Preferably, the second section 9 has a portion that extends distally from the top to the bottom in a side view of the cylindrical body 2, but in a part of the second section 9, the outer edge of the proximal opening 5 may extend distally from the bottom to the top. Also, in a part of the second section 9, the outer edge of the proximal opening 5 may extend parallel to the longitudinal axis x, or perpendicular to the longitudinal axis x. Furthermore, in the first section 8, there are no portions where the outer edge of the proximal opening 5 extends distally from the bottom to the top, nor portions that extend parallel to the longitudinal axis x, nor portions that extend perpendicular to the longitudinal axis x.

The boundary between the first section 8 and the second section 9 can be determined as follows: if the specific inclined portion 10 of the first section 8 is formed in a straight line, the distal end of the straight specific inclined portion 10 can be defined as the boundary. If the specific inclined portion 10 of the first section 8 is not straight, the boundary between the first section 8 and the second section 9 can be determined as the most proximal point located below the lower end of the upper 1/3 region of the cylindrical body 2, where the angle between the extending direction of the tangent to the outer edge of the proximal opening 5 and the longitudinal axis direction x is less than 10°.

Preferably, the second section 9 includes a portion of the cylindrical body 2 in a side view where the angle between the extending direction of the outer edge of the proximal opening 5 and the longitudinal axis direction x is less than 10°. When the second section 9 is formed in this way, it becomes easier for the second section 9 to be formed with a length greater than or equal to a predetermined length in the longitudinal axis direction x, and the effect of providing the second section 9 in the proximal opening 5 becomes easier to achieve.

The length x in the longitudinal axis direction of the second section 9 is preferably 0.3 times or more the outer diameter of the cylindrical body 2, more preferably 0.5 times or more, even more preferably 1.0 times or more, preferably 10 times or less, more preferably 9 times or less, and even more preferably 8 times or less. When the second section 9 is formed in this manner, when a bending force is applied to the proximal end of the cylindrical body 2, the cylindrical body 2 in the second section 9 becomes more likely to deform so that the lower part of the proximal opening 5 opens, and the proximal opening 5 becomes more likely to deform so that it widens further.

The second section 9 is preferably formed only in the lower half of the tubular body 2, and more preferably in the lower third of the tubular body 2. The formation of the second section 9 in this way makes it easier for the tubular body 2 to deform in the second section 9 so that the lower part of the proximal opening 5 opens when the proximal end of the tubular body 2 is located in a body cavity or a bent portion of a guide catheter. Furthermore, when the proximal end of the tubular body 2 is located in a body cavity or a bent portion of a guide catheter, the proximal opening 5 is more likely to bend in the first section 8 than in the second section 9. Therefore, the lumen 4 of the tubular body 2 is less likely to collapse, making it easier to maintain its initial shape, and making it easier to insert a treatment device through the proximal opening 5 of the tubular body 2.

In one embodiment, the outer edge of the proximal opening 5 in the second section 9 is formed such that, in a side view of the cylindrical body 2, there is no portion extending upward toward the distal side. Figures 2 and 5 show examples in which the second section 9 is formed in this manner. When the second section 9 is formed in this way, the proximal end of the cylindrical body 2 is less likely to bend in the second section 9 of the proximal opening 5 when it is located in a body cavity or a curved portion of a guide catheter.

As shown in Figure 2, the proximal opening 5 can be formed such that, in a side view of the cylindrical body 2, the angle between the extending direction of the outer edge of the proximal opening 5 in the second section 9 and the longitudinal axis x is smaller than the angle between the extending direction of the outer edge of the proximal opening 5 in the first section 8 below the lower end of the upper 1/3 region of the cylindrical body 2. In the embodiment shown in Figure 2, the proximal opening 5 is more likely to bend in the first section 8 than in the second section 9, and when the proximal end of the cylindrical body 2 is located in a body cavity or a curved portion of a guide catheter, the proximal opening 5 is less likely to bend in the second section 9.

As shown in Figure 5, the second section 9, in a side view of the cylindrical body 2, has a second B section 9B including the distal end of the proximal opening 5, and a second A section 9A between the first section 8 and the second B section 9B. The angle between the extending direction of the outer edge of the proximal opening 5 in the second A section 9A and the longitudinal axis x is smaller than the angle between the extending direction of the outer edge of the proximal opening 5 and the longitudinal axis x in the first section 8 below the lower end of the upper 1/3 region of the cylindrical body 2. The angle between the extending direction of the outer edge of the proximal opening 5 and the longitudinal axis x in the second B section 9B is larger than the angle between the extending direction of the outer edge of the proximal opening 5 and the longitudinal axis x in the second A section 9A. If the second section 9 is formed in this manner, even if the proximal opening 5 bends in the second section 9, it becomes less likely that a large distortion will occur at the distal end of the proximal opening 5, making it easier to insert the treatment device through the proximal opening 5 of the cylindrical body 2. In this case, it is preferable that the second B section 9B includes a portion in which, in a side view of the cylindrical body 2, the angle between the extending direction of the outer edge of the proximal opening 5 and the longitudinal axis direction x is 45° or more. The extending direction of the outer edge of the proximal opening 5 described herein means the extending direction of the straight line if the outer edge of the proximal opening 5 is formed in a straight line, and the extending direction of the tangent to the curve if the outer edge of the proximal opening 5 is formed in a curved shape.

In the embodiments shown in Figures 2 and 5, it is preferable that there is no portion in the second section 9 that extends parallel to the longitudinal axis x, or if there is, that not too much portion is formed in the longitudinal axis x. For example, in the second section 9, the length in the longitudinal axis x of the portion extending parallel to the longitudinal axis x is preferably 1/2 or less, and more preferably 1/3 or less, of the length in the longitudinal axis x of the second section 9. This makes it less likely for the lumen 4 of the cylindrical body 2 to collapse significantly even if the proximal opening 5 is bent in the second section 9.

In another embodiment, the outer edge of the proximal opening 5 in the second section 9 can be formed to have a shape that is convex upward when viewed from the side of the cylindrical body 2. Figure 6 shows an example in which the second section 9 is formed in this way. If the second section 9 is formed in this way, even if the proximal opening 5 bends in the second section 9, it will be easier to bend in the second section 9 without significant distortion occurring in the convex upward portion of the second section 9. As a result, the lumen 4 of the cylindrical body 2 will be less likely to collapse. Furthermore, when the cylindrical body 2 deforms in the second section 9 so that the lower part of the proximal opening 5 opens, a larger opening is formed in the lower part of the proximal opening 5, making it easier to insert a treatment device through the proximal opening 5 of the cylindrical body 2.

When the cylindrical body 2 is viewed from below, the width (maximum width) of the proximal opening 5 in the second section 9 is preferably 0.9 times or less the outer diameter of the cylindrical body 2, and more preferably 0.8 times or less. The formation of the second section 9 in this manner makes it easier for the cylindrical body 2 to deform in the second section 9 so that the lower part of the proximal opening 5 opens when the proximal end of the cylindrical body 2 is located in a body cavity or a bent portion of a guide catheter. On the other hand, when the cylindrical body 2 is viewed from below, the width of the proximal opening 5 in the second section 9 is preferably 0.05 times or more the outer diameter of the cylindrical body 2, more preferably 0.1 times or more, and even more preferably 0.2 times or more. If the second section 9 is formed in this manner, when the cylindrical body 2 deforms in the second section 9 so that the lower part of the proximal opening 5 opens, a larger opening is more easily formed in the lower part of the proximal opening 5.

The outer edge of the proximal opening 5 is preferably formed symmetrically with respect to the width direction, that is, the direction perpendicular to the longitudinal axis x and the vertical direction. Therefore, it is preferable that the outer edge of the proximal opening 5 is formed such that, in a side view of the cylindrical body 2, the portion on one side in the width direction and the portion on the other side overlap.

It is preferable that the linear member 13 is fixed to the cylindrical body 2 in the first section 8 and the second section 9. It is also preferable that the linear member 13 extends distal to the second section 9, that is, distal to 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 can bend smoothly from the cylindrical portion 3 to the first section 8 and the second 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 is less likely to collapse in the body cavity or the bent portion of the guide catheter.

The proximal extension portion 7 is preferably located proximal to the first section 8 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 through 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 7 of the tubular body 2 preferably has the inner layer and outer layer described above. It is preferable that the proximal extension portion 7 does not have a reinforcing layer. This allows the proximal extension portion 7 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 significant 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. 2021-169113, filed on 14 October 2021. The entire specification of Japanese Patent Application No. 2021-169113, 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: Proximal extension portion 8: First section 9: Second section, 9A: Second A section, 9B: Second B section 10: Specific inclined section 11: Tangent 12: Strip-shaped section 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.
In a plan view formed from the longitudinal axis direction and the vertical direction of the cylindrical body, the outer edge of the proximal opening has a first section that extends distally from the top to the bottom in a region at least between the upper 1/3 and lower 1/2 of the cylindrical body, and a second section located distal to the first section and including the distal end of the proximal opening.
The first section has a specific inclined portion, and the second section is formed above the tangent to the outer edge of the specific inclined portion.
In the second section, the outer edge of the proximal opening has no portion extending upward toward the distal side, and no portion extending parallel to the longitudinal axis, or a portion extending parallel to the longitudinal axis exists such that the length of the portion extending parallel to the longitudinal axis is 1/2 or less of the length of the second section in the longitudinal axis direction . The extension guide catheter according to claim 1, wherein the specific inclined portion is formed in a straight line, and the tangent line is an extension of the specific inclined portion formed in a straight line. In the first section, the outer edge of the proximal opening is formed to extend distally from the top to the bottom in a region between the upper one-third and lower one-third of the cylindrical body, as described in claim 1. The extension guide catheter according to claim 1, wherein the second section is formed only in the lower one-third region of the cylindrical body. The extension guide catheter according to claim 1, wherein the width of the proximal opening in the second section, when viewed from below, is 0.05 times or more and 0.9 times or less the outer diameter of the cylindrical body. The extension guide catheter according to claim 1, wherein the length of the second section is 0.3 times or more and 10 times or less the outer diameter of the cylindrical body. 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.