JP2000225198A5 - - Google Patents

Description

3. An artificial lumen composed of an expandable member and a tubular body made of cloth surrounding the expandable member; 1% by weight of fibers having a cloth of 0.089 g / km (0.8 denier) or less. An artificial lumen characterized by containing the above.

5. The artificial lumen according to claim 3, wherein the cloth contains fibers of 0.089 g / km (0.8 denier) or less.

For example, in a small vessel region, relative stenosis in peripheral arteries of the coronary arteries and limbs, the guide wire was inserted into a blood vessel, by inserting the stent is allowed to reach the narrow窄部along which the stenosis with a balloon There is a way to extend it and place it there. Palmaz's US Pat. No. 4,733,665 is a representative technique.

According to the present invention, an artificial lumen composed of an expandable member and a tubular body made of cloth surrounding the expandable member; fibers having a cloth of 0.089 g / km (0.8 denier) or less in weight ratio. An artificial lumen containing 1% or more is provided.

Further, if necessary, the linear member can take any known shape / structure (or a combination of two or more of these structures) such as monofilament, multifilament, and tape. This makes it possible to select and adjust the flexibility, restoring force, etc. of the linear member, and it is easy to create an expandable member having a curved surface adapted to the curved surface of the inner surface of the soft lumen (for example, blood vessel) wall. Become.

That is, in the embodiment of the present invention using such ultrafine fibers, the tubular body 3 preferably contains 1% or more of (fine) fibers of 0.089 g / km (0.8 denier) or less in terms of weight ratio. The content of the fiber of 0.089 g / km (0.8 denier) or less is preferably 2% or more, more preferably 3% or more. From the viewpoint that a brushed structure can be easily obtained, the tubular body 3 preferably contains 1% or more, more preferably 3% or more, particularly 5% or more of extremely fine fibers of 0.056 g / km (0.5 denier) or less.

<Method for confirming fiber weight ratio> The sliced sample is observed under an optical microscope in the same manner as described above. The number of each of the ultrafine fibers (for example, 0.089 g / km (0.8 denier) or less) and other fibers having a normal thickness is measured at 10 points ^{having an arbitrarily selected 10 mm 2 width.}

As described above, the cloth constituting the tubular body 3 in the present invention can be realized, for example, by mixing 1% or more of fine fibers of 0.089 g / km (0.8 denier) or less. Normal (non-ultrafine) fibers have a thickness of 0.133 g / km (1.2 denier) to 0.222 g / km (2.0 denier)) , and the cross-sectional diameter of the fibers is 16 μm (micron). It was 20 μm (micron) .

In the present invention, for example, in the embodiment in which fine fibers of 0.089 g / km (0.8 denier) or less are used, the fiber diameter is 5 μm (micron) or less ( 0.056 g / km (0.5 denier) or less). For fine fibers, the fiber diameter is 4 μm (micron) or less), but even if it is only 1% by weight, the number of fine fibers accounts for 3% or more of the total number of fibers, and further, the number of fine fibers accounts for 3% or more of the total number of fibers. The content of 5% by weight of the ultrafine fibers of 0.011 g / km (0.1 denier) or less means that the number of the ultrafine fibers far exceeds the number of other fibers in terms of the number of fibers, that is, a tubular body. No. 3 is composed of 50% or more of ultrafine fibers in number.

Among the non-woven fabrics, those in which fine fibers are randomly entangled (by a high-pressure water jet or the like) are particularly preferable. In the cloth of such an embodiment, the cut end is particularly hard to fray, and it becomes easier to prevent the cloth from losing its shape as a structure. Such entanglement of fibers (particularly extremely complicated entanglement) becomes easier when the tubular body 3 contains 1% or more of extremely fine fibers of 0.089 g / km (0.8 denier) or less.

The ratio (M / C) of the above-mentioned two types of wall thickness is preferably about 1.1 to 6, and more preferably about 2 to 5 (particularly about 2 to 4).

In order to satisfy the above-mentioned contradictory conditions, it is most preferable to use ultrafine fibers (0.089 g / km (0.8 denier) or less). The thickness of conventional polyester fibers, polyolefin fibers, and polyamide fibers is about 0.133 g / km (1.2 denier) to 0.222 g / km (2.0 denier) . With fibers of such conventional thickness, the thinning of the fiber by compression is limited, and the recovery of the thickness of the cloth by releasing the compression is limited even if it is in a brushed state, and the brushed structure is easily crushed by the compression. Even so, a certain amount of thickness remains. However, if the cloth is made of ultrafine fibers, the thickness can be suppressed at the time of compression, and the thickness may be restored when the compression is released. As a result of examining the thickness of the ultrafine fibers that do not affect the increase in thickness so much from this idea, the thickness of the ultrafine fibers and the total number of fibers are also affected, but 0.089 g / km (0. Fibers of 8 denier or less, further 0.056 g / km (0.5 denier) or less (particularly 0.044 g / km (0.4 denier) or less), at least 1% or more, and further 3% or more (particularly). By mixing them in a weight ratio of 5% or more), it becomes easy to satisfy both of the contradictory conditions.

Ultrafine fibers have a very fine fiber diameter as compared with ordinary fibers. For example, ordinary polyester fibers are about 0.133 g / km (1.2 denier) to 0.222 g / km (2.0 denier) . The cross-sectional diameter of the fiber is 16 to 20 μm (micron) . On the other hand, in the case of ultrafine polyester fiber at 0.022 g / km (0.2 denier) , the cross-sectional diameter of the fiber is about 3 μm (micron) .

In the present invention, the cloth is not simply thinned as in the prior art, but for example, extremely fine fibers of 0.089 g / km (0.8 denier) or less are mixed in the fibers constituting the cloth. As a result, the structure is devised so as to realize the predetermined physical properties of the cloth and induce an excellent anchoring state of cells and thrombi.

Furthermore, the entanglement of such fine fibers could be complicated and disorderly entangled as the thickness of the fibers became thinner. As a result of examining the fiber thickness according to the present invention, 0.089 g / km (0.8 denier) or less, further 0.056 g / km (0.5 denier) or less (particularly 0.044 g / km (0.4 denier)). When a tubular body 3 containing 1% or more of fibers of denier) or less) is used, such a complicated and disorderly entangled state of fibers can be easily obtained, and the suture retention test based on ANSI / AAMI is 0. It has been found that a fray resistance of 5.5 kg or more can be obtained.

When the strength of the thin cloth in which the ultrafine fibers were entwined in this manner was measured, it was 0.089 g / km (0.8 denier) or less, and further 0.056 g / km (0.5 denier) or less (especially). It has been found that 0.044 g / km (0.4 denier) or less) fiber needs to be contained in a weight ratio of at least 1% or more. Such a condition utilizes the method of entanglement of ultrafine fibers by water jet described in US Pat. No. 906347 (Special Fair 4-59899) US Pat. No. 4,695,280 and European Patent No. 128,741. It was found by the study of the present inventor that it can be easily obtained. Furthermore, it was also found by the study of the present inventor that a cloth made in this way can easily obtain a pressure resistance of 20 kg or more in the ANSI / AAMI standard burst test.

[0110]
【Example】
Example 1 (Preparation of various artificial lumens) An example (artificial blood vessel) of the configuration of the stent-type artificial lumen of the present invention is shown in FIG. As an example, a cloth tube with a bellows is made of 0.133 g / km (1.2 denier) denier normal thickness polyester fiber (50% by weight) and 0.022 g / km (0.2 denier) ultrafine polyester. A prototype was made using fibers (50% by weight) (prototype). Its inner diameter was 30 mm and its length was 10 cm. A Z-shaped stent for tracheoplasty that can be expanded to 40 mm was inserted into this as an example of a stent, and it was sutured and fixed with a 2-0 polyester multifilament thread. The water permeability of this cloth was about 150 ml · cm ² · min ^-1 .

On the other hand, as a control having a water permeability close to that of the above-mentioned "prototype", a cloth artificial blood vessel (made by Ube Industries, Ltd., UBE-graft) having the same thickness and the same length was prepared in the same manner, and Z was similarly prepared inside. A type stent was inserted and fixed. The water permeability of this cloth was about 120 ml · cm ² · min ^-1 (control product A). In this control product A, as shown in the schematic cross-sectional view of FIG. 3, fibers of ordinary fibers (thickness, about 20 μm (micron) ) are observed in a plain weave state. The weft 9 and the warp 10 are neatly intersected and finely woven, and there are almost no gaps.

Separately from this, a cloth artificial blood vessel (manufactured by Ube Industries, Ltd.), which was prototyped as a cloth that can be easily inserted into the sheath, was obtained, and another control product B having the same thickness and the same length was prepared. The water permeability of this cloth was about 250 ml · cm ² · min ^-1 (control product B). In this control product B, as shown in the schematic cross-sectional view of FIG. 4, fibers of ordinary fibers (thickness, about 20 μm (micron) ) are observed in a plain weave state. The weft 11 and the warp 12 are neatly intersected and finely woven, and there is almost no gap, but the thickness of the entire cloth is thin, and water may leak at the intersection of the warp and the weft.

Prototype and the control product A have closed their one end, enclosed by inserting a PVC tube other end, it was injected in this way the fresh blood collected from dogs after a 50ml lumen. As a result, both blood vessels were dyed red, and blood seemed to leak at first glance, but even when pressurized to a pressure of 120 mmHg, blood did not leak from the artificial blood vessel wall. Therefore, the water permeability of both is 150 ml ・ cm ²・ min ^-1 and 120 ml ・ cm ²・ min ^-1 , but leakage to blood can be prevented in both cases, and there is a large difference in water permeability. It turned out not.

Both who passed through the sheath could not find any change to the naked eye. However, when a part of both cloths was taken and observed with a scanning electron microscope (magnification: 40 times, 100 times, 400 times, 1000 times, 3000 times), the surface of the prototype was about 3 μm (micron). The ultrafine polyester fibers were brushed, and no disorder or damage was observed in these fibers.

On the other hand, in the control product A, no change was observed at a low magnification of 500 times or less, but when observed at 1000 times or more, the thickness of the polyester fiber was about 20 μm (micron) . A closer look at these fibers revealed that some of the fibers were crushed and many were damaged. However, no fiber rupture was observed.

When a part of the control product B after the passage test of the sheath was taken out and observed with a scanning electron microscope (magnification: 1000 times), the fiber had a diameter of 20 μm (micron) , and no damage was observed in the fiber. , Disorders in the texture were observed everywhere, and in the part where the metal was thought to have penetrated, large disturbances were seen in the texture, even though the fibers were not torn, and the fibers were scattered and holes were opened.

Further, according to the present invention, an artificial lumen composed of an expandable member and a tubular body made of cloth surrounding the expandable member; fibers having a cloth of 0.089 g / km (0.8 denier) or less in weight ratio. An artificial lumen containing 1% or more is provided.