JP3273264B2 - Introducer sheath - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an introducer sheath, and more particularly to a sheath (hereinafter referred to as "sheath") used to assist in inserting catheters and other equipment into the body, particularly into blood vessels. The present invention relates to an introducer sheath constituted by a sheath / dilator assembly capable of providing a stepped recess at a distal end portion of a dilator (hereinafter, referred to as a dilator) and fitting and embedding a distal end portion of a sheath into the dilator recess. Things.

[0002]

2. Description of the Related Art An introducer sheath is a sheath / dilator assembly in which a dilator is inserted into a sheath, and the tip of a tapered dilator projects to the tip of the sheath. The general assembly appearance is shown in FIG. FIG. 6 is an enlarged sectional view of the tip.
Shown in In both figures, a dilator 11 having a hollow portion 10 has a tapered tapered end projecting from a distal end of a sheath 12. Therefore, sheath 1
2 had a step 13 between the tip portion and the dilator 11. The step 13 becomes a major obstacle when passing through the skin, the subcutaneous tissue and the blood vessel wall, and not only increases the insertion resistance, but also causes pain and discomfort to the patient.

In order to improve this point, the above-mentioned step 13 is used.
Is proposed, for example, Japanese Patent Publication No. 4-6471.
No. 2, JP-A-3-15534. These have the structure shown in the schematic cross-sectional views of FIGS. 7 and 8 in principle, and eliminate the step 13 between the sheath 12 and the dilator 11 shown in FIG. A structure that obtains a transition portion is adopted. That is, the dilator has a structure in which the distal end of the sheath 12 is buried in the concave 14 using the dilator 11a having the annular recess 14 at the boundary with the sheath 12 at the distal end. In FIG. 7, the entire portion of the dilator covered by the sheath is recessed, so that the sheath outer diameter can be reduced as compared with the one in FIG. . In any case, the step 13 shown in FIG. 6 is eliminated.

[0004] The purpose of placing the sheath in a body or a blood vessel is to secure a passage in the lumen of the sheath and to smoothly insert various catheters and equipment using the passage. Accordingly, the sheath is made of a material having a relatively high rigidity that is inevitably bent against bending and hardly crushed by pressure from the outer periphery.

[0005]

Since the conventional introducer sheath as described above is made of a relatively hard and highly rigid material, when the sheath is placed in a body, especially in a blood vessel, a tissue which comes into contact with the tip of the sheath is introduced. The part will be damaged by compression and abrasion. Above all, there is a problem that in the case of a blood vessel, the intima is peeled off, and in the case of a remarkable blood vessel, there is even a risk of perforation of the blood vessel wall.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to prevent the above-mentioned damage and danger and to minimize the invasion of the patient's internal tissues. Introducer sheath (sheath
(A dilator assembly).

[0007]

An introducer sheath according to the present invention is configured such that a dilator is inserted into a sheath, and a distal end of the dilator can protrude from a distal end portion of the sheath. a introducer to be used as an auxiliary device for insertion into the body, inclined with respect to the tube axis in the vicinity of the tip of the dilator
Form an annular dent and make the distal end of the sheath hard at room temperature.
And made of a material that softens when heated to body temperature.
The tip end of the base can be inserted into the recess of the dilator.
Formed in an inclined shape, when the dilator and sheath are engaged
In addition to eliminating the steps between them,
To remove the dilator from the sheath
It is something that can be taken .

[0008]

In the present invention, the distal end portion of the sheath is formed of a material that is hard at room temperature but softens when heated to a temperature of about body temperature (body temperature softening material). When the transducer sheath is inserted, only the dilator is removed immediately after the insertion, and only the distal end of the sheath remains in, for example, a blood vessel.
In such a state, for example, the blood vessel wall moves due to body motion or pulse, and even in a state of rubbing against the sheath tip, the tip is heated by body temperature, so that the soft tip is sufficiently flexible. Minimize tissue damage. In addition, the above-mentioned body temperature softening material is a shape memory type resin material having a characteristic of rapidly softening at a temperature higher than the body temperature and reversibly hardening when the temperature returns to the body temperature or lower.

[0009]

【Example】

(Embodiment 1) FIG. 1 is an explanatory cross-sectional view of an introducer sheath showing an embodiment of the present invention, in particular, a distal end portion thereof.
FIG. 2 is a sectional view showing a distal end portion of the sheath of FIG. As is clear from FIG. 2, the sheath 22 is formed of two parts, a hard part 22b made of the same material as the conventional sheath 12, and a body temperature softening part 22a constituting the distal end. As shown in FIG. 1, a dilator 11a (see FIGS. 7 and 8) is inserted into the sheath 22, and the distal end of the dilator 11a projects from the distal end of the body temperature softening portion 22a of the sheath 22. , As in the conventional method.

The sheath 22 is bent at the time of insertion and placement in the body, and is extended to the distal end of a hard portion 22b of a relatively hard material having sufficient rigidity to secure a circular passage (lumen) against compression. At room temperature of several mm to several tens of mm, a soft body temperature softening portion 22a is joined or formed as a tip soft tip portion. Here, the body temperature softening part 22a and the hard part 22
Various pairs are conceivable as combinations of the materials b. For example, the following combinations are suitable for the introducer sheath. Hard part material Body temperature softening part material Polyurethane (hard) Polyurethane-based shape memory resin ^* * See JP-A-61-293214 (Mitsui Heavy Industries KK trademark: Diary)

The joining is performed by preparing a hard portion (hard polyurethane) of the sheath body having the same inner and outer diameters and a material (polyurethane shape memory resin) of the body temperature softening portion of the tip soft tip portion, and using an adhesive and a solvent. Other methods include overlapping the joints, covering them with a heat shrink tube, etc., then immersing them in a heat medium, melting and pressing to join them, or inside a heating mold that regulates the outer diameter and outer diameter It is possible to join by adopting various known methods such as a method of melting and joining together.

The flexible sheath at the distal end, that is, the sheath 22, manufactured by the above-described method is combined with the dilator 11a which has been positioned and recessed in advance so that the distal end of the sheath 22 fits into the recess 14 of the dilator. Thus, an intended sheath dilator assembly, that is, an introducer sheath according to the present invention is obtained.

The introducer sheath inserted into the body or the blood vessel by the operator is immediately removed from the dilator immediately after the insertion, and only the distal end of the sheath remains in the blood vessel, for example. In this detention state,
For example, even if the blood vessel wall moves due to body motion, pulse, etc., and rubs against the sheath tip, the softening of the body temperature makes the tip soft enough, so that damage to the tissue can be minimized. The effect that it can be obtained is obtained.

(Embodiment 2) FIGS. 3 and 4 are schematic explanatory views showing another embodiment of the present invention. FIG. 3 is a sectional view of a main part, and FIG. 4 is a side view of FIG. As is clear from both figures, the sheath 22 is composed of a hard part 22b and an inclined body temperature softening part 22c which constitutes a tip part thereof. The distal end of the inclined body temperature softening portion 22c forms an inclined distal end port 23 which is cut obliquely with respect to the tube axis of the sheath. Therefore, the dilator 11b is provided with the inclined tip port 2
3 is formed so as to have an oblique annular recess 15 that engages with the recess 3. That is, the dilator 11 b is formed at the oblique annular recess 15 through the inclined distal end port 23.
Are fitted and engaged with the sheath 22.

In the configuration of the second embodiment, the dilator and the sheath are fitted and engaged in the above-described inclined tip opening 23 to set a normal state. By twisting, the dilator 11b can be extracted from the sheath 22 more easily than in the first embodiment.

[0016]

As described above, according to the present invention, the sheath
The dilator is inserted and the tip of this dilator is
Is configured to protrude from the distal end of the catheter,
Used as an auxiliary device to insert other equipment into the body
Near the tip of the dilator in the introducer
An annular recess inclined to the tube axis is formed in the
The tip is hard at room temperature and softens when heated to body temperature
The tip of the sheath is made of
The dilator is formed into an inclined shape that can be
When the sheath is engaged with the sheath, the step between
Then, by twisting each other around the pipe axis, the sheath
Since the dilator can be removed from the body, in practical use, for example, in normal use where only the dilator is removed after inserting it into the body, especially into the blood vessel, and only the distal end of the sheath is left in the blood vessel, Even if the blood vessel wall moves due to movement, pulse, etc. and rubs against the sheath tip, the sheath tip is softened while in the body due to body temperature softening, so that the effect of minimizing damage to vascular tissue can be obtained. . The annular recess of the dilator is inclined with respect to the pipe axis.
The tip of the sheath that can be fitted and engaged in this recess
The dilator and the engaged dilator.
Are twisted around the pipe axis,
The dilator can be easily removed from the sheath.
Minimize pain and discomfort to patients when leaving
You.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of an introducer sheath of the present invention.

FIG. 2 is a cross-sectional view illustrating a main part of a sheath of the present invention.

FIG. 3 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 4 is a side view of FIG. 3;

FIG. 5 is an assembly external view of a conventional general introducer sheath.

FIG. 6 is an enlarged cross-sectional view of a tip portion of FIG.

FIG. 7 is a cross-sectional view of a main part of an introducer sheath without a conventional step.

8 is a sectional view of a main part showing an improved type of the conventional example of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hollow part 11, 11a, 11b Dilator 12, 22 Sheath 13 Step 14 Depression 15 Depression 22a Body temperature softening part 22b Hard part 22c Inclined body temperature softening part 23 Inclined tip mouth

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroyuki Matsumoto 5-27-7 Sendagaya, Shibuya-ku, Tokyo Japan Brunswick Building 5th Floor Inside Sherwood Co., Ltd. (56) References JP-A-3-60672 (JP, A) Japanese Utility Model 3-15534 (JP, U) Japanese Utility Model 4-108554 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61M 25/08 A61M 29/00

Claims (1)

(57) [Claims] 1. An introducer in which a dilator is inserted into a sheath, and a tip of the dilator is configured to protrude from a tip of the sheath, and is used as an auxiliary device for inserting a catheter and other equipment into a body. A ring inclined with respect to the tube axis near the tip of the dilator
Form a concave shape, the tip of the sheath is hard at room temperature
And made of a material softened by heating at body temperature.
Can be fitted into the dilator recess
Formed in an inclined shape, the dilator and the sheath
When engaging with
By twisting around the tube axis, the sheath
Introducer sheath characterized by the ability to remove the dilator .