JP3752281B2 - Balloon catheter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a balloon catheter provided with a wrapping sheath that covers the outer periphery of the balloon in a folded state.
[0002]
[Prior art]
Conventionally, many balloon catheters include a cylindrical wrapping sheath 201 as illustrated in FIG. 4, and the balloon 203 is covered with the wrapping sheath 201 during storage. This wrapping sheath 201 is used to maintain the folds attached to the balloon 203 during storage and to protect the balloon 203 from damage. When the balloon catheter is used, it has been removed prior to use. .
[0003]
[Problems to be solved by the invention]
However, according to the prior art, when the wrapping sheath 201 is removed, the balloon 203 may be unwound before the balloon 203 is completely inserted into the body, which makes it difficult to insert the balloon 203. If the balloon 203 is forcibly inserted with the balloon 203 unwound, the surface of the balloon 203 may be damaged, and conversely, the broken balloon 203 may damage the skin and the blood vessel wall.
[0004]
In response to such a problem, as illustrated in FIG. 5, a balloon catheter including a wrapping sheath 205 that is torn along the tear line 207 when the knob 209 is pulled away has been proposed. With this balloon catheter, the balloon 211 can be gradually exposed to the outside and gradually inserted into the body while tearing the wrapping sheath 205 gradually, so that the balloon 211 can be prevented from being unwound to some extent.
[0005]
However, even with such a balloon catheter, for example, the folded balloon 211 comes into contact with the sheath, or the folded balloon 211 comes into direct contact with the human body when performing sheathless insertion. May cause the balloon 211 to unravel, and it is difficult to completely prevent damage to the balloon 211 or damage to the skin or blood vessel wall.
[0006]
Then, an object of this invention is to provide the balloon catheter which can insert a balloon into a human body in the state which the folded balloon cannot be opened.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention is as described in claim 1.
A balloon catheter comprising a wrapping sheath that covers the outer periphery of the balloon in a folded state, and the wrapping sheath is configured to be inserted into a blood vessel together with the balloon while covering the balloon. ,
A tip is projected on the distal end side of the balloon, and a step portion is formed on the tip tip by partially reducing the diameter on the proximal end side rather than the distal end side,
The tip of the wrapping sheath is on the proximal end side of the stepped portion, and has a smaller diameter than the distal end side of the stepped portion.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to the balloon catheter of claim 1, since the balloon can be inserted into the blood vessel while the balloon is covered with the wrapping sheath, the balloon can be removed by removing the wrapping sheath after the balloon portion has completely entered the blood vessel. Does not melt before entering the blood vessel, and it does not make insertion difficult due to the melting. Moreover, the skin of the insertion site is not damaged by the broken balloon, and conversely, the balloon is not damaged. Furthermore, since the surface of the wrapping sheath can be a smooth surface with less irregularities than a folded balloon, it can be inserted into the human body more easily than the balloon regardless of whether or not it is unwound.
[0009]
By the way, one of the characteristic parts of the present invention is that, as described above, the wrapping sheath has a structure that can be inserted into the blood vessel together with the balloon while covering the balloon. Specifically, (1) the wrapping sheath has at least an outer diameter that can be inserted into a blood vessel, and (2) sufficient flexibility that does not hinder the flexibility of the folded balloon. (3) the tip side (distal end side) does not swell up during insertion, and (4) it can be easily removed after the balloon has been inserted into the blood vessel.
[0010]
Since (1) differs depending on the blood vessel to be inserted and individual differences among patients, it cannot be specified by a numerical value or the like. However, in order to suppress the blood circulation disorder as much as possible, the thinner the better.
Regarding (2) above, it is still impossible to specify numerical values or the like, but by adjusting the material and the thickness of the wrapping sheath, a desired flexibility can be given to some extent, so that the required strength is ensured. Therefore, it is desirable to be able to deform more flexibly.
[0011]
As for (3) above, a method in which the distal end portion of the wrapping sheath is adhered to or closely adhered to a member (for example, a balloon or a distal tip) can be considered. As a method of closely contacting, for example, the inside of the wrapping sheath is airtight and sufficiently decompressed, the dimension of the wrapping sheath is set slightly smaller than the outer diameter of the folded balloon, and the balloon is pushed into the wrapping sheath. Alternatively, a method is conceivable in which the wrapping sheath is formed of a heat-shrinkable resin material and the tip side is shrunk by applying heat. Furthermore, if there is a step at the boundary between the wrapping sheath and the member contained in the wrapping sheath on the distal end side of the wrapping sheath, there is a risk of applying a force that swells to the end of the wrapping sheath. Adjust the shape of the wrapping sheath to protect the end of the wrapping sheath, or adjust the shape of the wrapping sheath so that there is no large step at the boundary. It becomes difficult to apply extra power. In this regard, in the case of the balloon catheter according to claim 1, a stepped portion is formed in the tip of the tip by partially reducing the diameter at the proximal end side rather than the distal end side, and the tip of the wrapping sheath is formed at the stepped portion. Since the diameter is thinner than the distal end side of the stepped portion, the tip side end surface of the wrapping sheath is hidden behind the stepped portion of the tip tip as seen from the tip side. . With the wrapping sheath configured in this manner, even if the human body comes into contact with the human body when inserted into the body, the human body hardly comes into direct contact with the end surface on the distal end side, so that the distal end side of the wrapping sheath is hardly swollen. Therefore, compared to, for example, “a structure in which the end surface on the front end side of the wrapping sheath is not hidden behind the stepped portion”, the wrapping sheath does not need to be closely attached, and accordingly, toward the proximal end side. It is even easier to pull out and remove. In adhering or adhering, considering that the wrapping sheath is removed later, it is necessary to adhere or adher with such a force that it can be removed even though it does not swell.
[0012]
Regarding (4) above, the simplest way is to pull it out with the catheter shaft as the axis. For this purpose, when the balloon is inserted until it reaches the inside of the blood vessel, the rear end side of the wrapping sheath needs to be exposed outside the body by a length sufficient to pull out the wrapping sheath. Further, in order to prevent the balloon and the wrapping sheath from being damaged when pulled out, it is preferable that the frictional resistance between the wrapping sheath and the balloon is small. In addition, since the wrapping sheath which pulled out the catheter shaft through the shaft center can be removed from the catheter shaft, for example, by tearing or tearing, it is desirable that the structure be easily torn or torn in advance.
[0013]
In constructing the wrapping sheath that satisfies the conditions as described above, the material is not particularly limited, but synthetic resin materials (for example, polyurethane) generally used for medical devices can be used, and particularly thin. To make it soft and soft, a fluororesin (for example, polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-6 fluoropropylene copolymer resin (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether) A copolymer resin (PFA), tetrafluoroethylene-ethylene copolymer resin (ETFE), polytrifluoroethylene chloride (CTFE), polyvinylidene fluoride (PFV), or the like may be used.
[0014]
In order to facilitate the insertion of the catheter into the body, it is better that the frictional resistance of the outer peripheral surface of the wrapping sheath is smaller. To facilitate the extraction of the wrapping sheath outside the body, the inner peripheral surface of the wrapping sheath. The lower the frictional resistance, the better. However, to reduce such frictional resistance, the inner and outer peripheral surfaces of the wrapping sheath are hydrophilic polymers (for example, polyvinyl alcohol, carboxymethylcellulose, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyhydroxy). It may be coated with ethyl methacrylate, polyvinyl methyl ether, polyvinyl pyridine, polyethylene oxide, polyvinyl pyrrolidone, or the like.
[0015]
As mentioned above, although the main conditions for constituting the wrapping sheath in the present invention are specifically mentioned, other conditions such as the wrapping sheath made of a material that does not adversely affect the human body are naturally necessary.
In addition, for example, if it is determined that further flexibility is required after determining the material and thickness, it is possible to form countless minute holes on the side surface of the wrapping sheath, or to provide a plurality of grooves or slits. Good. In addition, the flexibility is improved even if the wrapping sheath is not formed into a tubular shape, but is formed in a strip shape spirally wound around the balloon.
[0016]
Further, for example, as a structure for preventing the wrapping sheath from curling up at the distal end side, there is a method in which a screw structure is provided and bonded in addition to the above-described adhesion or close contact, and the connection is released by applying torque.
Furthermore, for example, as a means for removing the wrapping sheath, in addition to pulling out the wrapping sheath, for example, a material that dissolves in the blood vessel (for example, sugar, starch, collagen, heparin, wafer etc.) is selected and wrapped. Means such as forming a sheath can be considered. In this way, the wrapping sheath is dissolved and removed after insertion of the catheter. In this case, similar to the resin material described above, a wrapping sheath may be formed first and attached to the balloon, but the material before molding is coated on the surface of the balloon and directly on the balloon. It is also possible to mold a wrapping sheath.
[0017]
In this way, there are various structures that can be inserted into the blood vessel together with the balloon while covering the balloon with the wrapping sheath. However, in any case, the balloon cannot be unwound before insertion into the body. The effect is that the balloon can be inserted into the body more smoothly than before.
[0018]
[Concrete example]
Next, in order to further clarify the embodiment of the present invention, a specific example of a balloon catheter to which the present invention is applied will be described with reference to the drawings. The specific examples described below are merely examples of the embodiments of the present invention, and the embodiments of the present invention are not limited to the specific examples illustrated below.
[0019]
As shown in FIGS. 1A to 1C, the balloon catheter 1 is a well-known double lumen type composed of a tip 3, a balloon 5, a shaft 7, a connector 9 and the like, and the balloon 5 is folded. In this state (see FIG. 1B), a wrapping sheath 11 that covers the outer periphery of the balloon 5 is provided.
[0020]
The wrapping sheath 11 is a bag made of a thin and flexible film having a hydrophilic polymer coating on the surface based on a fluororesin. As shown in FIG. 1 (a), the tip 11a is tapered. While the shape is narrowed down to a shape, a part of the rear end 11b is cut into two and a plastic knob 13 is attached to the outermost end. Further, a tear line 15 extends from the base of the above-mentioned tearing portion toward the tip 11a, and is easier to tear than other portions.
[0021]
The tip 11a of the wrapping sheath 11 is in close contact with the outer periphery of the tip 3 as shown in FIG. In order to make such a close contact, when the wrapping sheath 11 is formed, the tip 11a of the wrapping sheath 11 is squeezed narrower than the outer diameter of the tip tip 3, and the tip tip 3 is pushed in so that the wrapping sheath 11 is pushed into the balloon 5. You just have to install it.
[0022]
Alternatively, instead of the structure shown in FIG. 2 (a), as shown in FIG. 2 (b), the diameter is partially reduced at the proximal end side 3b rather than the distal end side 3a. The tip 11a of the wrapping sheath 11 may be on the proximal end side 3b of the stepped portion, and the diameter may be smaller than the distal end side 3a of the stepped portion. In addition, what has the structure provided with the level | step-difference part shown in FIG.2 (b) corresponds to embodiment of this invention.
[0023]
Since the balloon 5, the shaft 7, the connector 9 and the like are well known, detailed description thereof is omitted.
Next, the usage method of this balloon catheter 1 is demonstrated.
First, preparation for inserting the balloon catheter 1 is made in the same procedure as in a general sheathless insertion method. That is, one end plug is attached to the inflation port 21 (see FIG. 1A) provided in the connector 9 of the balloon catheter 1, and the inside of the balloon 5 is negatively pressured by sucking with a syringe through the one end plug. Keep it. Then, a blood vessel (for example, a femoral artery) is punctured using the puncture needle, a guide wire is inserted through the lumen of the puncture needle, and the puncture needle is pulled out. Next, a dilator is inserted along the guide wire, the punctured hole is sufficiently widened, and the dilator is pulled out. Then, the balloon catheter 1 is advanced along the guide wire.
[0024]
Here, in the case of the conventional balloon catheter, the wrapping sheath is removed at least before being inserted into the human body, but the balloon catheter 1 is still covered with the wrapping sheath 11 as shown in FIG. It is introduced along the guide wire 35 from the skin 31 into the blood vessel 33. In this balloon catheter 1, unlike the conventional balloon catheter, the tip 11a of the wrapping sheath 11 is structured so as not to bend up, so that the wrapping sheath 11 is not caught on the skin 31 or the like.
[0025]
Thus, the balloon catheter 1 is inserted for a length enough to allow the balloon 5 to enter the blood vessel 33. In this state, the wrapping sheath 11 is exposed to the outside of the skin 31 for a length sufficient to be pulled out. Yes. Therefore, if the wrapping sheath 11 is picked and pulled out to the hand side, only the wrapping sheath 11 can be pulled out of the body. The pulled wrapping sheath 11 can be removed from the shaft 7 by tearing the knobs 13 outward with both hands, as shown in FIG.
[0026]
After that, like the conventional balloon catheter, the balloon 5 is pushed along the guide wire 35 to a target position (for example, in the aorta), and connected to a known air driving device or the like to assist blood pressure. be able to.
As mentioned above, although the specific example of this invention was demonstrated, about the specific structure of this invention, various aspects other than the said specific example are employable.
[0027]
For example, as a specific example, a double lumen type balloon catheter frequently used in IABP or the like has been shown. However, a feature of the present invention is that the balloon can be inserted into a blood vessel while being covered with a wrapping sheath. The balloon catheter having such a structure can be applied to any of the balloon catheters used in other treatments (for example, PTCA), so that the balloon is prevented from being unwound and smooth sheathless insertion can be performed. In addition to the sheathless insertion, there is an advantage that even when the insertion is performed using the sheath, the balloon can be prevented from being unwound and can be smoothly inserted.
[0028]
【The invention's effect】
As described above, according to the balloon catheter of the present invention, the balloon does not break before entering the blood vessel, and insertion does not become difficult due to the breaking. Moreover, the skin of the insertion site is not damaged by the broken balloon, and conversely, the balloon is not damaged. Furthermore, since the surface of the wrapping sheath can be made smoother with less irregularities than a folded balloon, it can be inserted into the human body more easily than the balloon regardless of whether or not it is unwound.
[0029]
Further, according to the balloon catheter of the present invention, the distal end surface of the wrapping sheath is hidden behind the stepped portion of the distal tip as viewed from the distal end side, so that the wrapping sheath can be formed without excessively adhering the wrapping sheath. Can prevent the tip from rolling up.
[Brief description of the drawings]
FIG. 1 shows a balloon catheter as a specific example, in which (a) is a front view thereof, (b) is a partial front view with a wrapping sheath removed, and (c) is a partial front view with a balloon inflated. It is.
FIG. 2 is a partial cross-sectional view illustrating a structure in the vicinity of a distal end portion of a wrapping sheath.
FIG. 3 is an explanatory view showing a part of a procedure for inserting a balloon catheter.
FIG. 4 is a front view showing a conventional wrapping sheath.
FIG. 5 is a front view showing another conventional wrapping sheath.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Balloon catheter, 3 ... Tip, 5 ... Balloon, 7 ... Shaft, 9 ... Connector, 11 ... Wrapping sheath, 13 ... Pick, 15 ... Rupture Line, 21 ... Inflation port.

Claims (1)

A balloon catheter comprising a wrapping sheath that covers the outer periphery of the balloon in a folded state, and the wrapping sheath is configured to be inserted into a blood vessel together with the balloon while covering the balloon. ,
A tip is projected on the distal end side of the balloon, and a step portion is formed on the tip tip by partially reducing the diameter on the proximal end side rather than the distal end side,
A balloon catheter characterized in that a tip of the wrapping sheath is on the proximal end side of the stepped portion and has a diameter smaller than that of the distal end side of the stepped portion.

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