JPH08112355A - Medical vessel inserter - Google Patents

Abstract

(57) [Summary] [Purpose] A catheter introducer or indwelling needle is introduced into a blood vessel percutaneously with a small resistance and without damaging the tissue more than necessary. [Structure] An inner tube 1 which is an expansion tube (or an inner needle) is formed with a diameter-reduced step portion 3 and a long conical portion 4 which has a larger diameter toward the base end and recovers the outer diameter, and a sheath. (Or cannula) the outer tube 5 has a tapered tip 6
As a close contact with the long conical portion 4 and the tip edge 7
Was positioned substantially within the outer diameter of the reduced-diameter step portion 3 so that there was no step portion which was curved.

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the cannula with the tip protruding, the inner needle is punctured to the target site, and then the inner needle is withdrawn, and then a container or aspirator for blood or drug solution or an artificial kidney circuit. To connect 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 the 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. For this reason, 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. , The inner tube is provided with a reduced diameter stepped portion in an annular shape to form a long conical section that increases in diameter toward the base end and recovers the outer diameter, and the outer tube tip is closely attached to the long conical section. The tip edge of the cover is located almost within the outer diameter of the reduced diameter step portion. 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]

Function: The outer tube is percutaneously introduced into the blood vessel together with the distal end of the outer tube in close contact with the long conical section of the inner tube. At this time, since the tip edge of the outer tube is located substantially within the outer diameter of the stepped portion, there is no curved stepped portion. Therefore, the resistance is small and the insertion is smooth, and the tissue is not damaged to a predetermined extent. It will be introduced to the position.

[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. Further, a reduced-diameter step portion 3 is provided in an annular shape at the beginning of the tapered portion 2, and a long conical portion 4 that gradually increases in diameter toward the base end to recover the outer diameter.
Are formed.

The outer tube 5 is placed on the inner tube 1 with almost no clearance, and the tip is tapered and has a gradually decreasing thickness, and the conical tip 6 is closely attached to the long cone 4. At the same time, the rounded tip edge 7 is located within the outer diameter of the inner tube 1 and reaches near the reduced diameter step portion 3.

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 has a tip portion whose diameter gradually decreases along the long conical portion 4, and a rounded tip edge 7 has a reduced diameter step portion 3.
Since the inner tube 1 is covered in a state where there is no step that goes to the tip anyway, it can be inserted smoothly with a small resistance without being caught in the tissue when stabbed, and the tissue can be inserted more than necessary. It doesn't hurt.

Further, when the inner pipe 1 is pulled out, the conical tip portion 6 of the outer pipe 5 is expanded by the data portion 2, and after the inner pipe 1 is pulled out, it returns to its original shape by its own elastic force. 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 located within the outer diameter of the outer tube 5 so that the blood vessel wall is not damaged or peeled off. It's 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.

The tip of the inner tube 11 is formed with a blade portion 12 for puncturing, and a diameter reducing step portion 13 is provided in an annular shape slightly on the base end side thereof, and gradually increases toward the base end from that. A long conical portion 14 that has a diameter and recovers the outer diameter is formed.

The outer pipe 15 is covered with the inner pipe 11 with almost no clearance, and the tip portion is tapered and has a gradually decreasing thickness in the shape of a long cone, and the tip portion 16 of the cone is closely attached to the long cone portion 14. A rounded tip edge 17 is located inside the outer diameter of the inner pipe 11 and is in contact with the reduced diameter step portion 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 pipe 15 is covered with the inner pipe 11 in a state in which the rounded tip edge 17 is hidden by the reduced diameter step portion 13 and there is no step portion which goes to the tip. It does not get caught in the tissue during puncture, can be smoothly inserted with a small resistance, and does not damage the tissue more than necessary.

Further, when the inner tube 11 is pulled out, the conical tip portion 16 temporarily expanded is returned to its original shape by its own elastic force, so that the tip edge 17 may damage or peel off the blood vessel wall. It is also the same as the previous embodiment in that it is safe.

The tip edges 7 and 17 of the outer pipes 5 and 15 are rounded even by being exposed to the outside of the outer diameters of the inner pipes 1 and 11 from the diameter-reduced step portions 3 and 13. It is safe because it does not exist. Further, when the conical tip portions 6 and 16 are made thin, the reduced diameter step portions 3 and 13 are formed so shallow that the inner pipes 1 and 1
1 can be removed easily, which is not only advantageous in terms of operation, but especially in the case of a cannula for an indwelling needle, the tip part to be indwelled in the defect is highly flexible and there is no fear of damaging blood vessels. Has the advantage that

[0022]

As is apparent from the above description, the tip of the outer pipe is made into a tapered conical tip, and the tip of the inner pipe is made to closely adhere to the tapered long conical portion provided in the inner pipe. According to the present invention, which is positioned substantially within the outer diameter, there is no stepped portion which is rounded at the tip of the outer tube, the resistance is small when it is inserted into the body, it can be smoothly inserted, and the tissue can be damaged more than necessary. It is easy and safe to handle. Further, the long conical portion, the reduced diameter step portion and the conical tip portion 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 partially enlarged vertical sectional partial view of an embodiment of the present invention.

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

[Explanation of symbols]

1,11 Inner pipe, 3,13 Reduced diameter step, 4,14
Long conical part, 5,15 outer tube, 6,16 Conical tip 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 of, the reduced diameter step portion is provided in an annular shape at the distal end portion of the inner tube, and a long conical portion is formed that becomes larger in diameter toward the proximal end and recovers the outer diameter. The distal end portion of the outer tube is closely covered with the long conical portion, and the distal end edge is positioned substantially within the outer diameter of the reduced diameter step portion. 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.