JP3300155B2 - How to shape the tip of a medical guidewire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, blood vessels, ureters,
The present invention relates to a method of shaping a distal end portion of a medical guidewire used for inserting a catheter into a trachea or the like, or inserting an indwelling device inside a blood vessel aneurysm or the like.

[0002]

2. Description of the Related Art In recent years, for example, in a cardiac catheter examination, a technique of percutaneously inserting a catheter without incising a blood vessel and administering a drug such as a contrast agent to the blood vessel has been widely adopted. Was.

The procedure for percutaneously inserting a catheter will be described with reference to FIG. 6 taking an arterial puncture as an example. First, an artery 2 is punctured with a puncture needle 1 (a).
Then, the puncture needle 1 is pulled out while leaving the guide wire 3 in the artery 2 (b).

Next, a dilator 4 is attached to the outer periphery of the guide wire 3, and the tip of the dilator 4 is slid along the guide wire 3 and pushed into the artery 2 (c). When the extension is completed in this way, the extender 4 is removed (d),
Thereafter, the catheter 5 is slid along the guide wire 3 (e), and the catheter 5 is inserted into the artery 2 (f).

[0005] When the catheter 5 is inserted to a predetermined position in the artery 2, the guide wire 3 is removed, and then a drug such as a contrast agent is administered to the artery 2 via the catheter 5.

As described above, when the catheter 5 is inserted, the guide wire 3 for guiding the catheter 5 is used. In addition, the catheter 5 is used for examining blood vessels as described above,
It is used not only for treatment but also for examination and treatment of all tubular organs of the human body such as the ureter and the trachea.

[0007] As the above-mentioned guide wire, there is known a guide wire having a core wire whose tip portion is gradually narrowed, and a coil attached to the entire outer periphery of the core wire or only the tip portion. This guide wire has rigidity to the extent that operability is not lost by the core wire, and flexibility is provided by the outer coil, so that the distal end of the core wire is made thin so as not to damage the tubular organ. The tip is particularly flexible.

In this case, stainless steel, shape memory alloy, or the like is used as the core wire, and stainless steel, platinum, or the like is used as the outer peripheral coil.

When a guidewire is inserted into a blood vessel or trachea, it is necessary to turn the proximal end of the guidewire and guide the guidewire into a tube aimed at the distal end of the guidewire at the branch point because the guidewire is partially branched. is there.

For example, as shown in FIG. 7, the distal end of a blood vessel 45 into which a guide wire 41 is inserted is branched into branch tubes 46 and 47, and a target examination or treatment site is a branch tube 46.
, It is necessary to turn the proximal end of the guide wire 41 so that the distal end thereof is directed toward the branch pipe 46.

[0011] In order to facilitate such an operation, when inserting a guide wire, the distal end thereof has to be appropriately formed on the spot according to the patient. Also, a guide wire having a distal end portion mechanically bent into a J-shape from the beginning is commercially available.

[0012]

However, in the case of a guide wire whose core wire is made of stainless steel or the like, even if the distal end is mechanically bent into a J shape, for example, it is extended through a very thin and long catheter. Then, the shape bent by the elasticity of the core wire itself may return to the original shape, and it may be difficult to perform the above operation at the branch point of the blood vessel.

Further, in the case of a guide wire whose core wire is made of a shape memory alloy, it is difficult to bend it due to the superelasticity of the shape memory alloy, and it has not been possible to form a desired shape. If the tip is bent at the time of manufacturing the core wire, it becomes difficult to mount the coil on the outer periphery thereafter.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to form a distal end portion of a guide wire into a desired shape, and furthermore, to form a guide wire having a bent shape even though it is passed through a catheter. It is an object of the present invention to provide a method for shaping the distal end portion of a medical guide wire, in which the pressure is maintained well.

[0015]

In order to achieve the above object, the present invention forms a distal end of a medical guide wire having a metal core wire and a metal coil mounted on the outer periphery thereof into a desired shape. The method, wherein the core wire is stainless steel;
The coil is made of stainless steel and the coil is made of stainless steel.
Less, platinum, platinum alloy, gold, tungsten
It is made of a selected material, and is characterized in that the distal end of the medical guidewire is inserted into a mold so as to be maintained in a desired shape, and is heated.

In carrying out the present invention, the heat treatment is preferably performed at 400 to 600 ° C. for 30 to 300 minutes.

Further , the tip of the medical guide wire is
A lid plate after being inserted into the mold having a linear recess formed on the inner surface
It is preferable to cover with
Good.

Furthermore, the coil is flop Rachina, platinum alloys, gold, and more preferably an X-ray opaque material such as tungsten.

[0019]

Conventionally, in the method of bending the tip of the guide wire, the bent shape is maintained by plastically deforming the core and the tip of the coil. However, even if the core wire and the coil are plastically deformed, the residual stress remains, so that when inserted into a catheter or the like and stretched, the shape returns to the original shape due to the residual stress.

According to the method of the present invention, the distal end of the core wire and the coil are plastically deformed by inserting the distal end of the guide wire into a mold and holding it in a desired shape, and performing a heat treatment. Stress is also reduced. For this reason, the distal end portion of the guide wire can be formed in a desired shape, and the shape is maintained even when it is extended through a catheter or the like, and does not return to the original shape.

[0021]

[0022]

[0023]

[0024]

FIG. 2 shows an example of a guide wire used in the present invention. The guide wire 11 includes a core wire 12, a safety wire 13, and a coil 14 arranged on the outer periphery thereof.

The core wire 12 is stainless steel, made of a material such as carbon steel, the tip portion 12a is formed in a tapered shape. The wire diameter of the core wire 12 is preferably 0.1 to 1.0 mm.

The safety wire 13 is for preventing the coil 14 from being stretched, and is made of the same material as the core wire 12, and its wire diameter is appropriately set within a range in which the above object is achieved.

The coil 14 is made of stainless steel, platinum, a platinum alloy, gold, tungsten, or the like , and has a wire diameter of preferably 0.03 to 0.5 mm and an outer diameter of 0.1 to 0.5 mm.
1.5 mm is preferred.

The base ends of the core wire 12, the safety wire 13, and the coil 14 are fixed to a base 15 made of brazing material.
Further, the distal ends of the safety wire 13 and the coil 14 are fixed to a head 16 made of a brazing material, and the head 16 has a hemispherical shape so as not to damage the tissue of the tubular organ. Note that the distal end of the core wire 12 is not fixed to the head 16, making the distal end of the guide wire 11 more flexible.

The length of the guide wire 11 varies depending on the application site, but is usually 300 to 3000 mm.

FIG. 3 shows another example of the guide wire used in the present invention. This guide wire 21
The distal end portion 22a of the core wire 22 is formed into a tapered shape with a predetermined length, and a coil 23 is mounted on the outer periphery of the distal end portion 22a.
The base of the coil 23 is fixed to the core wire 22 with a brazing material 24, and the tip of the coil 23 and the core wire 22 is a head 25 made of a brazing material.
It is configured to be fixed to.

The materials of the core wire 22 and the coil 23 are the same as those described above, but the coil 23 is made of platinum,
More preferably, it is made of a radiopaque material such as gold or tungsten. The wire diameter of the core wire 22 is 0.2 to 1.0 mm
Is preferable, and the wire diameter of the coil 23 is 0.03 to 0.3 mm.
Preferably, the outer diameter of the coil 23 is 0.1 to 1.0.
mm is preferred.

FIG. 1 shows a method of the present invention for shaping the distal end into a desired shape using the above-described guide wire. Here, a description will be given using the guide wire 11 of FIG. 2. For example, a J-shaped linear concave portion 32 is formed on the inner surface of the mold 31, and the tip of the guide wire 11 is inserted into the concave portion 32. , And cover it with a cover plate (not shown) to maintain the shape.

In this state, the mold 31 and the guide wire 1
1 in a heating furnace (not shown), for example, 400 to 600
C. for 30 to 300 minutes. Thereafter, when the guide wire 11 is taken out from the mold 31, the distal end portion 11a of the guide wire 11 is formed in a J-shape as shown in the figure.

Experimental Example A guide wire 11 as shown in FIG. 2 was manufactured. As the core wire 12, a stainless wire having a wire diameter of 0.45 mm was used, and the tip 12 a was formed in a tapered shape. Further, a stainless wire having a cross section of 0.07 × 0.35 mm was used as the safety wire 13. Further, as the coil 14,
A tight coil made of stainless steel having a wire diameter of 0.15 mm and an outer diameter of 0.89 mm was used.

The distal end portion of the guide wire 11 was placed in a mold as shown in FIG. 1 and heated at 592 ° C. for 120 minutes to bend into a J-shape (hereinafter referred to as an example product). ).

On the other hand, for comparison, the same guide wire 11 as above was mechanically bent into a J-shape to produce a comparative example.

These guide wires were repeatedly inserted and removed through a tube formed of polyethylene, and the radius of curvature R of the portion formed in a J-shape was measured at predetermined times. Table 1 shows the results.

Further, the initial shape of the tip portion of the product of the embodiment, 10
FIG. 4 shows the shape at the 100th round, and FIG. 5 shows the same shape as the comparative example. 4 and 5, (a) shows the initial shape, (b) shows the tenth shape, and (c) shows the 100th shape.

[0039]

[Table 1]

From the results shown in Table 1 and FIGS. 4 and 5, the shape of the example product hardly changes regardless of how many times it is put in and out of the tube, while the product of the comparative example increases in and out of the tube. It can be seen that the curvature gradually increases and returns to the original shape.

FIG. 8 shows another example in which the distal end portion of the guide wire shown in FIG. 3 is shaped by the method shown in FIG.

In this example, the tip of the guide wire 21 is
It is shaped so as to form a circulating loop, and is mainly used for treatment of heart diseases and the like. In this case, the loop diameter is 1
0 to 50 mm is preferable, and the number of loops is preferably 1 to 2 rounds.

This guide wire 21 is required to return to a loop shape as shown in FIG. 8 when it is stretched in a straight line and inserted into the heart through a catheter. In the method of bending in the heart, it was not possible to return to the loop shape when inserted into the heart.

However, when the distal end portion of the guide wire 21 is shaped by the method of the present invention shown in FIG. 1, even when the guide wire 21 is stretched straight and passed through the catheter, it returns to a clean loop shape as shown in FIG. . Therefore, it was very effective in treating heart diseases such as mitral stenosis.

[0045]

As described above, according to the present invention,
By inserting the tip of the guide wire into the mold and holding it in the desired shape, and then performing heat treatment, the tip of the guide wire could be shaped into the desired shape, and the shape could be shaped no matter how many times the catheter was passed. The shape can be maintained. For this reason, the distal end of the guide wire is shaped into a desired shape, and at the branch point of the tubular organ, the operation of turning the proximal end of the guide wire to guide the distal end of the guide wire into the target tube is facilitated. it can. Further, the distal end of the guide wire can be formed in a loop shape suitable for treatment of heart disease and the like.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method of shaping a distal end portion of a guide wire into a desired shape according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a guide wire used in the present invention.

FIG. 3 is a sectional view showing another example of a guide wire used in the present invention.

FIG. 4 is an explanatory diagram showing a change in the shape of the distal end portion when a guide wire obtained by the method of the present invention is repeatedly inserted into and removed from a tube.

FIG. 5 is an explanatory diagram showing a change in the shape of a distal end portion when a guide wire obtained by a conventional method is repeatedly taken in and out of a tube.

FIG. 6 is an explanatory view showing a general catheter insertion method.

FIG. 7 is an explanatory diagram showing an example when a guide wire is guided into a blood vessel.

FIG. 8 is a sectional view showing another example of a guide wire obtained by the method of the present invention.

[Explanation of symbols]

 11, 21 guide wire 12, 22 core wire 14, 23 coil 31 mold 32 linear recess

Continuation of the front page (56) References JP-A-59-67968 (JP, A) JP-A-4-108456 (JP, A) JP-A-3-41966 (JP, A) JP-A-1-170475 (JP) JP-A-1-170474 (JP, A) JP-A-1-135363 (JP, A) JP-A-1-99571 (JP, A) JP-A-60-261465 (JP, A) 3-24144 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61M 25/09

Claims (3)

(57) [Claims] 1. A method for shaping a distal end of a medical guide wire having a metal core wire and a metal coil attached to an outer periphery thereof into a desired shape, wherein the core wire is made of stainless steel,
The coil is made of stainless steel and the coil is made of stainless steel.
Less, platinum, platinum alloy, gold, tungsten
It is made of a selected material, wherein the distal end of the medical guide wire is inserted into a mold and held in a desired shape, and is subjected to a heat treatment. Method. 2. The heat treatment is performed at 400 to 600 ° C. for 30 minutes.
2. The method for forming a distal end portion of a medical guidewire according to claim 1, wherein the method is performed for about 300 minutes. 3. The distal end of the medical guide wire is placed on an inner surface.
After being inserted into the mold having a linear recess formed in the
And heat treatment is performed so as to maintain a desired shape.
3. The method for forming a distal end portion of a medical guidewire according to 2.