JPH07246241A - Blood vessel insertion means for medical treatment - Google Patents

Abstract

PURPOSE:To percutaneously introduce a catheter introducer or indwelling needle with small resistance into a blood vessel without giving more than needed flaws to tissues. CONSTITUTION:The front end of an inside tube 1 which is an expanding tube (or inside needle) is provided with an annular groove 3 and the front end of an outside tube 5 which is a sheath (or cannula) is converged by curving the front end inward. This converged part 6 is fitted into the groove 3 and the front end edge 7 of the outside tube 5 is positioned in the outside diameter of the inside tube 1, by which the structure without having bulky stepped parts is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical instrument for percutaneously introducing into a blood vessel, that is, a catheter introducer or an indwelling needle.

[0002]

2. Description of the Related Art A catheter introducer used for percutaneously introducing a catheter for diagnosing or treating a blood vessel or organ into a blood vessel is composed of a dilation tube having a small diameter and a sheath. Connect the proximal hubs to each other and insert the expansion tube into the sheath with the tip protruding.
A guide wire previously inserted into a blood vessel is fitted with an expansion tube and inserted into the body, the sheath is introduced into the blood vessel, the guide wire and the expansion tube are removed, and then the catheter is inserted into the sheath and the target site is inserted. To reach. Also,
An indwelling needle that is punctured and placed in a blood vessel or a bile duct for blood transfusion or infusion, or conversely, for blood removal or effusion, consists of an inner needle for puncture and a cannula (catheter) for indwelling. And hub are connected to each other, the inner needle is inserted through the cannula with the tip protruding, the inner needle is punctured to the target site, and then the inner needle is withdrawn, and then a container or aspirator for blood or drug solution or an artificial kidney circuit. Is connected to the cannula.

That is, these have a two-layer structure of an expansion tube or an inner needle which is an inner tube and a sheath or a cannula which is an outer tube, and are pierced into a human body in a state where the inner tube is projected more forward than the outer tube. Get caught. Therefore, the outer tube has a shape in which the tip edge of the outer tube forms a rounded step (in the case of a catheter introducer, Japanese Utility Model Publication No. 1-112849,
For an indwelling needle, see Japanese Utility Model Laid-Open No. 5-35149).
When puncturing, the tissue may be caught and hinder the insertion, or the tissue may be damaged more than necessary.

On the other hand, in consideration of the long introduction distance, it is required for the catheter to have a considerable hardness as a whole except for the distal end portion. Therefore, the inner tube and the outer tube, which are in close contact with each other, are required. A catheter having a two-layer structure has been proposed in which the inner tube is projected more forward than the outer tube, and the tip of the outer tube is gently inclined toward the tip to have a small diameter so that the tip is equal to the outer diameter of the inner tube ( Actual fairness 4-12
992). In this way, the outer tube does not have a rounded leading edge, so that the outer tube can be inserted smoothly and the fear of unnecessarily damaging the tissue is eliminated.

However, in practice, it is extremely difficult to form the tip portion of the outer tube smoothly without any step at the tip edge, and even if the outer tube can be formed so as to have no step, a catheter introducer or an indwelling device can be used. In the case of removing one of the inner tube and the outer tube after insertion like a needle, if there is a slight gap between them, the outer tube tip, which is thinned, has a step that is caught by the tissue and has a step. You get the same result. Therefore, it is not advisable to apply the idea of the catheter in which the inner tube and the outer tube are closely integrated to each other to a vascular insertion tool of a type in which one of the inner tube and the outer tube is withdrawn after the insertion.

[0006]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is a two-layer structure of an inner tube and an outer tube, wherein the inner tube is inserted into the outer tube with its tip portion protruding, The point that the outer tube tip of the medical blood vessel insertion tool that has a structure in which either one is removed after being introduced into the blood vessel by the skin may interfere with the insertion or may damage the tissue to people. Is.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a medical blood vessel insertion instrument which can smoothly insert a tissue without damaging the tissue. , Providing an annular groove at the tip of the inner pipe and curving the tip edge of the outer pipe inward, and inserting the throttle portion into the groove to position the tip edge of the outer pipe within the outer diameter of the inner pipe It was configured. In this configuration, a catheter introducer that uses an expansion tube as an inner tube, a sheath as an outer tube, and an expansion tube is removed after introducing a blood vessel, or an inner needle as an inner tube and a cannula as an outer tube after introducing the blood vessel It is applied to indwelling needles with the inner needle removed.

[0008]

Operation: The outer tube is percutaneously introduced into the blood vessel in a state in which the narrowed portion at the tip edge portion is fitted into the groove of the inner tube and is integrally put together. At this time,
Since the tip edge of the outer tube is fitted into the groove and is located within the outer diameter of the inner tube, and the tip edge of the outer tube has a curved surface that curves inward, there is no rounded step. Therefore, the resistance is small and the insertion is smooth, and the tissue is introduced to a predetermined position without damaging the tissue.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an embodiment in which the present invention is applied to a catheter introducer, which is a small-diameter expansion tube made of a soft synthetic resin. The inner tube 1 and the outer tube 5, which is also a thin sheath made of a soft synthetic resin, are connected to each other by connecting hubs (not shown) at their bases to the outer tube 5 so that the outer tube 5 has a distal end portion. It is projected and inserted.

The tip of the inner tube 1 is tapered so that the diameter becomes smaller toward the tip, and the inner diameter of the tip is made equal to the diameter of the guide wire. An annular groove 3 having a substantially V-shaped cross section is provided at the beginning of the tapered portion 2.

The outer tube 5 is covered with the inner tube 1 with almost no clearance, and the tip edge is curved inwardly and is squeezed, and the squeezed portion 6 is fitted in the groove 3 along the peripheral wall 3a on the base end side. , The tip edge 7 is located within the outer diameter of the inner tube 1, and the tip side peripheral wall surface 3 of the groove 3 is
It touches b.

In this embodiment having such a structure, just like the conventional catheter introducer, the inner tube 1 which is an expansion tube is fitted into the guide wire previously inserted into the blood vessel and inserted into the body. In this way, the outer tube 5 which is a sheath to be inserted as a unit is introduced into the blood vessel, and then the guide wire and the inner tube 1 are removed, and then the catheter is inserted into the outer tube 5 and guided to the target site. Is.

The outer tube 5 is in a state where the tip edge 7 is hidden in the groove 3 by contacting the tip side peripheral wall surface 4, and the tip edge portion is formed as a narrowed portion 6 which is curved inward, so that there is no stepped portion. Since it is covered with the inner tube 1, the tissue is not caught at the time of insertion and the tissue can be smoothly inserted with a small resistance and the tissue is not damaged more than necessary.

When the inner pipe 1 is pulled out, the narrowed portion 6 of the outer pipe 5 is pushed out by the peripheral wall surface 4 on the tip side and escapes from the groove 3, and after the inner pipe 1 is pulled out, its own elastic force. Press again to return to the inward curved state. Therefore, even if the outer tube 5 moves during removal of the inner tube or insertion of the catheter, the distal end edge 7 is positioned within the outer diameter of the outer tube 5 by the narrowed portion 6, so that the blood vessel wall is damaged or peeled off. There is no such thing and it is safe.

FIG. 2 shows an embodiment in which the present invention is applied to an indwelling needle, and an inner tube 11 which is an inner needle having a small diameter made of metal,
Outer tube 1 which is a small diameter cannula made of soft synthetic resin
5, the inner tube 11 is inserted into the outer tube 15 with its tip protruding by connecting a needle base (not shown) of these bases and a hub to each other.

A puncture blade 12 is formed at the tip of the inner tube 11, and an annular groove 13 having a substantially V-shaped cross section is provided at a slightly proximal end thereof.

The outer tube 15 is covered with the inner tube 11 with almost no clearance, and the tip edge portion is curved inwardly and squeezed, and the squeezed portion 16 is fitted in the groove 13 along the peripheral wall 3a on the base end side. The tip edge 17 is located within the outer diameter of the inner pipe 11 and is in contact with the tip side peripheral wall surface 13 b of the groove 13.

In this embodiment having such a structure, a blood vessel is percutaneously punctured into a blood vessel in the same manner as the conventional indwelling needle, and then the inner tube 11 which is the inner needle is pulled out to form the outer tube 15 which is the cannula. It is connected to a container for blood or a drug solution, an aspirator, or an artificial kidney circuit in a detained state.

Also in this embodiment, the outer tube 15 has the leading edge 17
Is concealed inside the groove 13 in contact with the peripheral wall surface 14 on the distal end side, and is covered with the inner pipe 11 in the state where there is no stepped portion which is the narrowed portion 16 with the distal end edge curved inward. In addition, the tissue is not caught during the puncture, can be smoothly inserted with a small resistance, and the tissue is not damaged more than necessary.

Further, when the inner tube 11 is pulled out, the narrowed portion 16 which has been temporarily expanded returns to the state of being curved inward again due to its own elastic force, so that the tip edge 17 damages or peels off the blood vessel wall. It is also the same as the previous embodiment in that it is safe without any problems.

The grooves 3 and 13 are not limited to the V-shaped cross section, but may be U-shaped or any other shape as long as the outer tube is fitted and the tip edge is located within the outer shape of the inner tube.

[0022]

As is apparent from the above description, the distal end portion of the outer tube is curved inward and squeezed, and the distal end edge is positioned within the outer diameter of the inner tube by fitting it into the annular groove provided in the inner tube. According to the present invention, there is no stepped portion at the tip of the outer tube, the resistance is small when it is inserted into the body, it can be smoothly inserted, and it does not damage the tissue more than necessary, and it is easy and safe to handle. It is a worm. Further, the narrowed portion and the annular groove can be molded very easily, and the structure in which the rounded step portion does not exist can be easily formed.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of an embodiment of the present invention.

FIG. 2 is a partial vertical sectional view of a different embodiment of the present invention.

[Explanation of symbols]

1 11 inner tube, 3 13 groove, 3b 13b tip side peripheral wall surface, 5 15 outer tube, 6 16 throttle part,
7 17 tip edge,

Claims (3)

[Claims] 1. A two-layer structure of an inner tube and an outer tube, wherein the inner tube is inserted into the outer tube with a tip portion protruding, and one of which is withdrawn after being percutaneously introduced into a blood vessel. In the medical blood vessel insertion tool, the inner tube is provided with an annular groove at the distal end thereof, and the distal edge of the outer tube is curved and squeezed inward, and the narrowed portion is provided in the groove. A medical blood vessel insertion tool, wherein the distal end edge of the outer tube is fitted and positioned inside the outer diameter of the inner tube. 2. The medical blood vessel insertion tool according to claim 1, which is a catheter introducer in which the expansion tube is an inner tube and the sheath is an outer tube, and the expansion tube is removed after introducing the blood vessel. 3. A medical blood vessel insertion tool, wherein the insertion tool according to claim 1 is an indwelling needle in which the inner needle serves as an inner tube and the cannula serves as an outer tube, and the inner needle is withdrawn after introducing the blood vessel.