JP2010183958A - Stent expansion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably and easily expand a stent in the body cavity. <P>SOLUTION: A stent expansion device 1 includes: an outside balloon 2 which is longer than the length in the longitudinal direction of a cylindrical stent and comprises an elastic material contractible to a size large enough to be insertable in a contracted stent vertically in the longitudinal direction; an inside balloon 3 which is shorter than the length in the longitudinal direction of the stent in the longitudinal direction and comprises an elastic material placed almost in the center in the longitudinal direction inside the outside balloon 2; an outside tube 4 which opens to both sides gripping the inside balloon 3 inside the outside balloon 2 in the longitudinal direction and has a first supply/discharge port 4a for supplying a space between the outside balloon 2 and the inside balloon 3 with fluid or discharging the fluid from the space; and an inside tube 5 which has a second supply/discharge port 5a opening to the inside of the inside balloon 3 and supplying the fluid to the inside of the balloon 3 or discharging the fluid from the inside balloon 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stent expansion device.

  Conventionally, stents and balloon catheters are known as medical devices that expand a narrowed body cavity to secure a space (see, for example, Patent Document 1 and Patent Document 2). When a stent is introduced into a body cavity in a contracted state and then a balloon is inflated, the stent expands in the body cavity to support the inner wall of the body cavity, and a cavity can be continuously secured in the body cavity. . In the case of the digestive tract such as the esophagus, physical stress due to peristaltic movement is applied, and thus the strength and the material of the stent are required.

  In addition, medical devices in which another balloon is provided in the balloon are known (see, for example, Patent Document 3, Patent Document 4, and Patent Document 5). It is used for the purpose of cooling the tissue surrounding the body cavity by storing a low-temperature liquid in the inner balloon or in the space between the inner surface of the outer balloon and the outer surface of the inner balloon.

  On the other hand, a magnesium alloy (Mg alloy) whose main component is magnesium, an essential biological element, is known as a metal material having high strength and bioabsorbability. When the Mg alloy is embedded in the body, it is gradually absorbed from the surrounding tissues, so that it is decomposed over time and disappears after a certain period.

Special Table 2002-520095 gazette JP 2003-230629 A JP-T-2002-536106 Special table 2003-524506 Special table 2007-537839 gazette

  However, in the case of Patent Document 1 and Patent Document 2, since the balloon is inflated first from the portion where the expansion of the end of the stent is not restricted, it is difficult to sufficiently inflate the balloon in the stent. There is a problem of not being able to give enough. Moreover, when the balloon is inflated from the end of the stent, a longitudinal compressive force is applied to the stent. At this time, if the balloon is continuously inflated and the compressive force is increased, there is a problem that there is a possibility that the stent may be broken before the stent is expanded, particularly when a stent made of an Mg alloy having a small breaking strain is used.

  Moreover, since the double balloon of patent document 3, patent document 4, and patent document 5 is designed in order to cool the living body, it is unclear whether it can be used for the expansion of a stent. In addition, since the specification is not suitable for mounting and using a stent, there may be inconveniences such as the stent being displaced and coming off the balloon during operation in a body cavity.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a stent expansion device capable of reliably and easily expanding a stent in a body cavity.

In order to achieve the above object, the present invention provides the following means.
The present invention is made of an elastic material having a length dimension longer than the longitudinal length of the cylindrical stent and capable of contracting in a direction perpendicular to the longitudinal direction to a size that can be inserted into the contracted stent. An outer balloon, and an inner balloon made of an elastic material having a length dimension shorter than the longitudinal length of the stent in the length direction, and made of an elastic material disposed in the outer balloon at a substantially center in the length direction; A first supply / exhaust port that opens on both sides of the inner balloon in the lengthwise direction inside the outer balloon and supplies fluid to the space between the outer balloon and the inner balloon or discharges fluid from the space. And an inner tube having a second supply / discharge port that opens into the inner balloon and supplies fluid into the inner balloon or discharges fluid from the inner balloon. To provide a door expansion unit.

  According to the present invention, the deflated outer balloon and the inner balloon are inserted into the deflated stent, and the outer balloon and the inner balloon are interposed from the first and second supply / discharge ports through the outer tube and the inner tube. By supplying fluid into the space and the inner balloon, each balloon can be inflated to expand the stent. Further, by expanding the stent and then discharging fluid from each balloon into each tube and deflating each balloon, the balloon can be removed while the stent is expanded, and only the stent can be placed.

In this case, the stent is disposed at a substantially central portion in the longitudinal direction of the outer balloon, the inner balloon is first inflated to expand the substantially central portion of the stent, and then the inner balloon of the outer balloon is sandwiched. The ends of the stent are expanded to expand the ends of the stent.
In this way, the outer balloon is prevented from being inflated from the end of the stent, and the outer balloon disposed over the entire length in the longitudinal direction in the stent is surely inflated in the stent.

That is, according to the present invention, the stent can be reliably secured in the body cavity by applying a radial expansion force to the stent reliably while preventing the stent from being broken by an easy operation of simply supplying fluid into each tube. Can be extended.
Further, by expanding the stent first in the substantially central portion, the balance of both ends can be maintained even if the stent is expanded only partially, so that the position of the stent can be stabilized and easily expanded.

In the above invention, the outer surface of the outer balloon may be provided with a convex portion that protrudes radially outward and engages the stent in the longitudinal direction in a contracted state.
By doing so, the longitudinal movement of the stent relative to the outer balloon is restricted in the contracted state, and the position of the stent is prevented from deviating from the outer balloon. Thereby, the position of the stent can be easily operated while maintaining the position with respect to each balloon.

In the above invention, the elastic material is an ethylene-α-olefin copolymer, an ethylene-vinyl acetate copolymer, a crosslinked ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, polyamide elastomer, It is preferable to include at least one of polyimide, polyimide elastomer, silicone rubber, and natural rubber.
In this way, each balloon can have elasticity suitable for expanding the stent.

  According to the present invention, it is possible to reliably and easily expand a stent in a body cavity.

It is sectional drawing which shows the detail of (a) whole block diagram and (b) front-end | tip part of the stent expansion apparatus which concerns on this embodiment. It is a figure explaining the operation method of the stent expansion apparatus of FIG. 1, (a) The state which each balloon was deflated, (b) The state which expanded the inner balloon, (c) The state which expanded both balloons Each is shown. It is a figure which shows the modification of an outer side balloon.

An embodiment of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1A and 1B, a stent expansion device 1 according to this embodiment includes an outer balloon 2, an inner balloon 3 disposed in the outer balloon 2, and each balloon 2, 3. Is provided with an outer tube 4 attached to the tip portion and an inner tube 5 accommodated in the outer tube 4.

  The outer balloon 2 and the inner balloon 3 cover the tip portion of the outer tube 4 in the circumferential direction to seal a gap between the outer tube 4, a space between the inner surface of the outer balloon 2 and the outer surface of the inner balloon 3, The inside of the balloon 3 is isolated. The outer balloon 2 has a longer dimension in the direction along the longitudinal direction of the outer tube 4 than the stent used, and the inner balloon 3 is used in the direction along the longitudinal direction of the outer tube 4. Has a shorter length dimension. Further, the inner balloon 3 is disposed at the approximate center in the length direction of the outer balloon 2.

  Further, the entire outer surface of the outer balloon 2 is provided with a convex portion 2a protruding outward in the radial direction. Accordingly, when the outer balloon 2 is inserted into a stent having a hole penetrating in the wall thickness direction on the side surface, the convex portion 2a is inserted into the hole of the stent and is engaged with the stent in the longitudinal direction.

  The outer balloon 2 and the inner balloon 3 are made of an elastic material having moderate elasticity for expanding the stent and high safety to the living body. Examples of the elastic material include an ethylene-α-olefin copolymer, an ethylene-vinyl acetate copolymer, a crosslinked ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, Silicone rubber, natural rubber and the like are preferable. Moreover, as ethylene of an ethylene-alpha-olefin copolymer, polyethylene, a polyethylene terephthalate, a polypropylene, an ethylene-propylene copolymer etc. are preferable, for example.

The inner tube 5 has an outer diameter smaller than the inner diameter of the outer tube 4, and a space is formed between the outer peripheral surface of the inner tube 5 and the inner peripheral surface of the outer tube 4. Are isolated from each other.
In addition, on the side surface of the outer tube 4, first supply / exhaust ports 4 a are opened on both sides of the inner balloon 3 in the outer balloon 2. The supply / discharge port 5a is opened.

  Connectors 4b and 5b are provided at the base ends of the tubes 4 and 5, respectively. For example, by connecting a syringe, a pump, or the like to these, fluid is supplied to the space between the inner peripheral surface of the outer tube 4 and the outer peripheral surface of the inner tube 5, and the inside of the inner tube 5. The fluid is discharged from the inside.

  When the fluid is supplied to or discharged from the outer tube 4, the fluid flows into the space between the inner surface of the outer balloon 2 and the outer surface of the inner balloon 3 from the first supply / discharge port 4 a, or the fluid is discharged from the space. Thus, the outer balloon 2 is inflated or deflated. Further, when the fluid is supplied or discharged into the inner tube 5, the fluid flows into the inner balloon 3 from the second supply / discharge port 5a, or the fluid flows out from the inner balloon 3, so that the inner balloon 3 is inflated. Or it can be shrunk.

  Further, in a state where the balloons 2 and 3 are deflated, each balloon 2 is set such that the outer diameter of the outer balloon 2 in the direction orthogonal to the longitudinal direction of the outer tube 4 is smaller than the inner diameter of the stent in the deflated state. 3 and the outer diameter of each tube 4 and 5 are designed.

The operation of the stent expansion device 1 configured as described above will be described below.
In the present embodiment, a case where a narrowed portion of a body cavity is expanded using a cylindrical stent 6 in which fine Mg alloy wires are formed in a mesh shape will be described as an example.

  In order to expand a stenosis part of a body cavity using the stent expansion device 1 according to the present embodiment, as shown in FIG. 2A, the balloons 2 and 3 in the contracted state are inserted into the stent 6 in the contracted state. Then, the stent 6 is disposed at a substantially central portion in the length direction of the outer balloon 2. When the stent 6 is introduced to the stenosis site in the body cavity, the fluid is first supplied to the inner tube 5 to inflate or expand the outer balloon 2 and the substantially central portion of the stent 6 as shown in FIG. .

  Next, when fluid is supplied to the outer tube 4 and both end portions of the outer balloon 2 are expanded, both ends of the stent 6 are also expanded as shown in FIG. It is done. Subsequently, when the fluid is discharged from the tubes 4 and 5 and the balloons 2 and 3 are returned to the contracted state and retracted outside the body, only the stent 6 expands and is left in a state of supporting the inner wall of the body cavity. Thus, a space can be secured continuously in the body cavity.

  Thus, according to the present embodiment, the outer balloon 2 is reliably inflated over the entire length in the longitudinal direction in the stent 6 by first inflating a part of the outer balloon 2 in the substantially central portion of the stent 6. . Accordingly, there is an advantage that the stent 6 can be reliably expanded in the body cavity by reliably applying a radial expansion force to the stent 6 by a simple operation of simply supplying the fluid into the tubes 4 and 5. is there.

  In addition, since the outer balloon 2 is prevented from expanding from both ends not restricted by the stent 6, the stent 6 can be expanded without being applied with a compressive force in the longitudinal direction. Thereby, even if it uses Mg alloy with a small fracture | rupture distortion as a material of the stent 6, there exists an advantage that it can expand reliably, without making it fracture.

  Further, by using the stent 6 made of Mg alloy in this way, when the stent 6 is placed in the body cavity, Mg is gradually absorbed from the surrounding tissue and disappears after a certain period of time. As a result, when the stenosis is improved after the operation and the stent 6 becomes unnecessary, or when the stent 6 needs to be removed after a certain period of time, the stent 6 is removed without re-operation. There is an advantage that the burden of can be greatly reduced.

  In addition, by expanding the stent 6 first from the substantially central portion, even if only a part of the stent 6 is in an expanded state, the both ends are balanced. Therefore, since the stent 6 is maintained in a stable position without being displaced with respect to the outer balloon 2, there is an advantage that the operation can be facilitated.

  Further, by providing the convex portion 2 a on the outer surface of the outer balloon 2, even if the stent 6 is caught by an obstacle while guiding the body cavity, the struts 6 a constituting the mesh of the stent 6 are convex. The movement in the longitudinal direction of the stent 6 is restricted by being caught by 2a. Thereby, there exists an advantage that the stent 6 can be easily guide | induced within a body cavity, maintaining the position with respect to each balloon 2 and 3. FIG.

In the above embodiment, as shown in FIG. 3, the convex portion 2a of the outer balloon 2 is provided with a holding member 2b protruding in the length direction of the outer balloon, for example, a disc-shaped rubber. Also good.
By doing in this way, the movement of the stent 6 with respect to the outer balloon 2 can be more reliably restricted, and the position of the stent 6 can be further stabilized.

DESCRIPTION OF SYMBOLS 1 Stent expansion apparatus 2 Outer balloon 2a Protruding part 2b Holding member 3 Inner balloon 4 Outer tube 4a First supply / exhaust port 4b Connector 5 Inner tube 5a Second supply / exhaust port 5b Connector 6 Stent 6a Strut

Claims (3)

An outer balloon made of an elastic material having a length dimension longer than the longitudinal length of the cylindrical stent, and contractible in a direction perpendicular to the longitudinal direction to a size that can be inserted into the contracted stent;
An inner balloon made of an elastic material having a length dimension shorter than the longitudinal length of the stent in the length direction, and arranged in the outer balloon at a substantially central position in the length direction;
A first supply / exhaust port that opens on both sides of the inner balloon in the lengthwise direction inside the outer balloon and supplies fluid to or discharges fluid from the space between the outer balloon and the inner balloon An outer tube having
A stent expansion device comprising: an inner tube having a second supply / discharge port that opens into the inner balloon and supplies fluid into the inner balloon or discharges fluid from the inner balloon.   The stent expansion device according to claim 1, wherein a convex portion that protrudes radially outward and engages the stent in a longitudinal direction in a contracted state is provided on an outer surface of the outer balloon.   The elastic material is ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, silicone rubber. The stent expansion device according to claim 1 or 2, comprising at least one of natural rubber.

Images