JP2002191697A - Dilator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dilator of which puncture resistance variation at inserting is small, puncture resistance value is low, and insertion property is sufficient. SOLUTION: In this dilator 1 equipped with a cylindrical body part 1b and a tapered tip part 1a, a taper shape of the tip part 1a is an outline R constituted by n continuous lines or curved lines and the outline R is formed to be positioned outside with respect to a straight line T connecting a tip of the tip part 1a, a first straight line from the tip, n-th straight line from an end of the curved line, or the end of the curved line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to dilators used to assist in inserting catheters and other devices into the body, especially into blood vessels.

[0002]

2. Description of the Related Art A dilator used as an aid when a catheter and other devices are inserted into a body (intravascular) is used alone or together with other devices, but is used here together with an introducer sheath. The case of using will be described as an example.

FIG. 3 is an enlarged sectional view of the distal end of an introducer sheath having a conventional dilator. In the figure, reference numeral 11 denotes a dilator having a hollow portion 12,
The distal end 11a is formed in a tapered shape and projects from the distal end of the sheath 13 of the introducer sheath. The tip 1 of the dilator 11
The taper 1a is formed in a straight line connecting the tip of the tip 11a to the end of the taper.

[0004] In the introducer sheath in which the dilator 11 is inserted into the sheath 13, a guide wire (not shown) previously placed in a blood vessel is inserted into the hollow portion 12 of the dilator 11 to introduce the introducer.
The sheath is percutaneously inserted into the blood vessel along the guide wire. Next, the dilator 11 having the skin and blood vessels dilated is removed, and a catheter (not shown) is inserted into the sheath 13 so that the guide wire is inserted into the lumen. To be introduced.

[0005]

The above-mentioned conventional dilator 11 is used for the purpose of facilitating insertion of a large (thick) catheter into a small incision at the time of normal insertion. However, since the distal end 11a of the dilator 11 is formed by a linear taper, the puncture resistance increases as the insertion depth increases, and when passing near the end of the taper (X in FIG. 3), the abruptness increases. Since the puncture resistance changes, the operator may feel poor operability.

Here, the puncture resistance will be described in more detail. For example, when a dilator having an outer diameter of 8 French (approximately 2.7 mm) having a linear taper is inserted into the skin, the dilator passes near the end of the taper (X in FIG. 3) as shown by a solid line A in FIG. At this time, the puncture resistance (puncture resistance change and puncture resistance value) becomes maximum (X in FIG. 4). Also,
Inspection of the resistance when the skin is pulled at a constant speed reveals that the resistance curve sharply rises from a displacement of about 5 mm (= φ1.6 mm) as shown in FIG. That is, when the skin is expanded at the time of piercing, the skin expands little near the tapered tip of the tip of the dilator (Y in FIG. 3), so that the increase in resistance due to tightening of the skin is small (FIG. 5). Y) is near the end of the taper (X in FIG. 3)
Since the resistance due to the tightening of the skin increases, the resistance sharply increases (X in FIG. 5). Further, since the resistance hardly increases after passing through the tip portion of the dilator, that is, after passing through the tapered portion, the same force as when passing through the straight tapered portion is applied after passing through the vicinity of the end of the taper (X in FIG. 3). The dilator may move rapidly in the insertion direction, and in some cases, may cause blood vessel puncture.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a small change in puncture resistance upon insertion.
It is another object of the present invention to provide a dilator having a low puncture resistance and good insertability.

[0008]

SUMMARY OF THE INVENTION A dilator according to the present invention is a dilator having a cylindrical body and a tapered tip, wherein the tip is tapered.
A contour line consisting of n continuous straight lines or curves, and the contour line connecting the end point of the first straight line or curve counted from the tip of the tip or the end point of the first straight line or curve to the end point of the nth straight line or curve. It is formed so as to be located on the outside with respect to this.

The dilator according to the present invention is characterized in that each of the tangents to the tip of the tip or an outer shape line consisting of n continuous straight lines or curves from the end point of the first straight line or curve from the tip, 1 from the tip of the part or from the tip
The angle formed by the n-th straight line or the straight line connecting the end point of the curve from the end point of the n-th straight line or the curve to the end of the tip portion is θ1, and the angle formed by θ1 is the closest to the base of the tip portion. When the angle formed is θn, the relationship among the n angles satisfies θ1 ≧ θ2 ≧ θ3... ≧ θn.

In the dilator according to the present invention, the angle θ1 formed closest to the tip of the tip portion is set to 0 ° <θ1 ≦ 5 °.

In the dilator according to the present invention, the ratio L / D of the outer diameter D of the trunk to the axial length L of the tip is 5 ≦ L / L.
D ≦ 15.

The dilator according to the present invention has a coating which exhibits surface lubricity when wet, at least on a part of the outer surface of the tip.

The dilator according to the present invention is obtained by subjecting the tip of the tip to thermal processing.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an enlarged sectional view of a main part of an embodiment of the present invention. In the figure, reference numeral 1 denotes a dilator which is an auxiliary tool for inserting a catheter into a blood vessel or the like by, for example, the Seldinger method, and a hollow portion 2 into which a guide wire or the like is inserted substantially at the center in the axial direction.
Is provided, and the tip portion 1a is formed in a tapered shape.

The taper is composed of n continuous straight lines or curves, and the taper of the tip 1a is defined by a straight line T connecting the tip of the tip 1a and the end point of the n-th straight line or curve counted from the tip. Outline line R is located outside (swells)
It is formed as follows. The angle θ formed between the tangent S (S1 to Sn) of n straight lines or curves from the tip and the straight line T and the angle formed closest to the tip of the tip 1a is θ1, and the angle θ is the closest to the base of the tip 1a. When the close angle is θn, the n angles θ1, θ2, θ3,.
1 ≧ θ2 ≧ θ3... ≧ θn, and in order to obtain this relationship, the angle θ1 formed closest to the tip of the tip 1a is 0.
゜ <θ1 ≦ 5 ゜. This substantially eliminates the difference between the n-th tangent line Sn and the outer shape of the trunk 1b of the dilator 1 excluding the distal end 1a, and the distal end 1a and the trunk 1b when the dilator 1 is inserted into a blood vessel or the like. This is to eliminate an extreme resistance difference from the above and enhance the insertability. On the base side of the tip 1a, the angle θ formed by the tangent S and the straight line T also takes a negative value.

Further, the relationship of L / D, which is the ratio of the outer diameter D of the body 1b to the axial length L of the tip 1a, is 5 ≦ L /
D ≦ 15. This is because if the value of the ratio L / D exceeds 15, the length L of the tip 1a becomes too long, which may cause a problem in the strength of the dilator 1, especially the strength of the tip 1a. If the value of D is smaller than 5, the resistance at the time of insertion of the distal end portion 1a becomes too large, and the function as the dilator 1 may not be achieved.

In the first embodiment, as shown in FIG. 1, the tip 1a is formed by a taper consisting of n continuous straight lines or curves from the tip, but the present invention is not limited to this. , As shown in FIG.
For example, the distal end portion G may be subjected to a heat treatment for smoothing in order to have insertability and strength, and may have a taper having an outer shape line R composed of n continuous straight lines or curves from the end point G1 excluding the distal end portion G. .

In the first embodiment having the above-described structure, the dilator 1 is provided similarly to the conventional dilator.
And an introducer sheath having a sheath (not shown) into which the dilator 1 is inserted,
A guide wire (not shown) previously placed in a blood vessel is inserted into the hollow portion 2 of the dilator 1, and an introducer sheath is percutaneously inserted into the blood vessel along the guide wire to dilate the skin and the blood vessel. Let it. At this time, FIG.
As shown by the one-dot chain line B, the change in the puncture resistance when passing through the vicinity of the taper end of the dilator 1 (X1 in FIG. 1) is small, and the puncture resistance value is also reduced, so that the rise in the puncture resistance can be suppressed. Is improved.

Next, the dilator 11 is removed, a catheter (not shown) is inserted into the sheath so that the guide wire is inserted into the lumen, and the catheter is introduced to the target site along the guide wire. Then, the guide wire and the sheath are removed, and a drug solution or the like is administered to the target site via the catheter.

As described above, the tip portion 1a of the dilator 1
Is composed of n consecutive straight lines or curves,
Since the outer shape line R of the front end portion 1a is located outside the straight line T connecting the front end of a and the n-th straight line or the end point of the curve counted from the front end, the taper is formed. A dilator with good insertability that can reduce the change in puncture resistance when passing through the skin near the terminal end X1 and can also reduce the puncture resistance value, thereby reducing the burden on the operator and the patient. 1 can be obtained.

Embodiment 2 FIG. Embodiment 2 according to the present invention
In the dilator 1 according to the first embodiment, at least a part of the outer surface of the distal end portion 1a of the dilator 1,
For example, it is provided with a coating which exhibits surface lubricity when wet with blood, body fluid or aqueous solution.

With such a structure, substantially the same operation and effect as those of the first embodiment can be obtained, and as shown by a two-dot chain line C in FIG. (X1), the change in puncture resistance is small, the puncture resistance value is also low, and the subsequent increase in puncture resistance can be suppressed. This makes it possible to obtain a dilator 1 with good insertability that can reduce the burden on the operator and the patient.

[0023]

As described above, in the dilator according to the present invention, in a dilator having a cylindrical body and a tapered tip, the tip is tapered to n.
For a contour line consisting of a series of straight lines or curves, and the contour line connecting the end point of the first straight line or the curve counted from the tip of the tip or the end point of the nth straight line or the curve, Since it is formed so as to be positioned on the outer side, a change in puncture resistance when passing through the skin at the distal end, particularly near the end of the taper, can be reduced, and the puncture resistance can be reduced. Thereby, a dilator having good insertability can be obtained.

The dilator according to the present invention is characterized in that each of the tangents to the front end of the front end portion or an outline formed of n continuous straight lines or curves from the end point of the first straight line or curve from the front end; 1 from the tip of the part or from the tip
The angle formed by the n-th straight line or the straight line connecting the end point of the curve from the end point of the n-th straight line or the curve to the end of the tip portion is θ1, and the angle formed by θ1 is the closest to the base of the tip portion. When the angle formed is θn, the relationship among the n angles is θ1 ≧ θ2 ≧ θ3... ≧ θn, so that a dilator having a tip with a small puncture resistance change and a low puncture resistance value is obtained. be able to.

In the dilator according to the present invention, the angle .theta.1 formed closest to the tip of the tip is 0.degree. <. Theta.1.ltoreq.5.degree. The difference can be eliminated, and a dilator having good insertability can be obtained.

In the dilator according to the present invention, the ratio L / D of the outer diameter D of the body to the axial length L of the tip is 5 ≦ L /
Since D ≦ 15, the resistance at the time of insertion is suppressed,
The strength of the tip can be increased, and a dilator with good insertability can be obtained.

In the dilator according to the present invention, since at least a part of the outer surface of the tip portion is coated with a film exhibiting surface lubricity when wet, the change in puncture resistance is reduced and the puncture resistance value is also reduced. And a dilator with good insertability that can reduce the burden on the operator and the patient can be obtained.

In the dilator according to the present invention, since the tip of the tip is subjected to thermal processing, the strength of the tip can be increased and a dilator having improved insertability can be obtained.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of a modification of the embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a distal end portion of an introducer sheath having a conventional dilator.

FIG. 4 is a diagram showing a penetration curve into the skin of the first and second embodiments of the present invention and a conventional dilator.

FIG. 5 is a diagram showing a tensile resistance curve of the skin.

[Explanation of symbols]

 Reference Signs List 1 dilator 1a tip 1b torso D outer diameter of torso G tip L length of tip R outer shape S tangent T straight line θ angle between tangent and straight line

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yosuke Okada 5-27-7 Sendagaya, Shibuya-ku, Tokyo Japan Brunswick Building Inside Shawd Japan Co., Ltd. (72) Kenichi Amano 5-chome Sendagaya, Shibuya-ku, Tokyo No. 27-7 Japan Brunswick Building Nippon Sharp Co., Ltd. F-term (reference) 4C167 AA23 BB02 BB06 BB38 BB41 CC08 FF10 HH14

Claims (6)

[Claims] 1. A dilator having a cylindrical body portion and a tapered tip portion, wherein the tip portion has a taper formed of n continuous straight lines or curved lines, and The line is formed so as to be located outside the tip of the tip or the straight line connecting the end of the nth straight line or the curve from the end of the first straight line or the curve counted from the tip. Dilator. 2. A tangent to a tip of the tip or an outer shape line consisting of n continuous straight lines or curves from an end point of a first straight line or curve counted from the tip, and a tip of the tip or the tip of the tip. The angle formed between the first straight line or the end point of the curve and the straight line connecting the end point of the n-th straight line or the curve from the end point to the end point of the front end portion is θ1; When the angle formed closest to the base of the tip is θn, the relationship between the n angles is θ1 ≧ θ
2 .gtoreq..theta.3... .Gtoreq..theta.n.
The described dilator. 3. An angle .theta.1 formed closest to the tip of the tip portion.
Is set to 0 ° <θ1 ≦ 5 °.
The described dilator. 4. An outer diameter D of a body portion and an axial length L of a tip portion.
The dilator according to any one of claims 1 to 3, wherein the ratio L / D with respect to satisfies 5 ≦ L / D ≦ 15. 5. The dilator according to claim 1, wherein at least a part of the outer surface of the distal end portion is coated with a film exhibiting surface lubricity when wet. 6. The dilator according to claim 1, wherein the tip of the tip is heat-processed.