JPH03184565A - Medical balloon and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain a balloon whose position and shape can be confirmed by MRI by forming the balloon from a bag body made of a flexible membrane in which an MRI contrast medium is dispersed so that the expanded shape thereof is a hollow cylindrical one and both ends of the cylindrical shape in the longitudinal direction thereof become fine in a funnel-like or spherical shape in the direction approaching the longitudinal axis thereof and small holes are provided to both ends. CONSTITUTION:A balloon 25 has a cavity therein and a large number of spherical projections 10a are distributed on the membrane of the balloon 25 and filled with fat globules 6. A bullet having one end of a wire fixed thereto is fixed to the opening of the cylindrical projection formed to one end of the balloon and a tube (catheter) is fixed to the opening of the cylindrical projection provided to the other end thereof and the balloon 25 is incorporated in a balloon pump. Since fat generates an MR phenomenon, MRI photographing is possible. When the balloon 25 is incorporated in the balloon pump to be inserted in a living body and subjected to MRI photographing, the images of fat globules 6 appear on an MRI image along the outer shape of the balloon 25 and, therefore, the position and shape of the balloon 25 can easily and visually be confirmed from the MRI image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a medical balloon that is inserted into a living body to promote or stop the flow of fluid within the living body.

(Prior art) For example, a balloon pump that assists the function of a living heart is one
For example, US Pat. No. 4,327,709.

It is disclosed in the specifications of No. 4,362,150 and No. 4,422,477. One conventional balloon pump is shown in FIG. 4, and this balloon pump 60 has a flexible thin film balloon 25 connected to a tube (catheter) 22. A Y-shaped base 21 that is always outside the body is connected to the tube 22, and a gas flow path is open in the center of the base 21, which branches into a Y-shape.
One branch 20 is connected to a pumping drive (not shown)
connected to. A probe 24 is airtightly and rotatably attached to the other branch. One end of the tube 22 is connected to the main trunk of the gas flow path, and the tube 22
One end of a balloon 25 is fixed to the other end.

The other end of the balloon 25 is fixed to a bullet 26.

An elastic wire 23 passes through the inside of the balloon 25 and the tube 22, and one end of the wire 23 is fixed to the probe 24 and the other end is fixed to the bullet 26. Figure 4 shows 1 branch road 2
When a negative pressure is applied to the 0 branch path 20, which indicates a state in which the balloon 25 is inflated by applying a positive pressure to 0, the gas inside the balloon 25 is sucked out, so that the balloon 25 contracts toward the wire 23.

Note that this balloon pump 60 is inserted into the aorta and positioned close to the heart, as shown in FIG. 5a.
Before using the balloon pump 60, the balloon 25 needs to have a thin outer shape in order to facilitate insertion of the balloon 60 into the aorta and delivery to a predetermined position.
4 is rotated in the normal direction around the wire 23, thereby rotating the wire 23 and the bullet 16, the balloon 25 is twisted and wound tightly around the wire 25 in the form of a string, and in this state, FIGS. As shown in FIG. 5c, after inserting the balloon 60 into the living body and placing it in a predetermined position, the probe 24 is rotated in the opposite direction and the wire is rotated back to untwist the balloon 25, allowing the balloon 25 to be inflated. restore to state. When positive pressure is applied to the branch passage 20 in this restored state.

Balloon 25 is inflated as shown in Figures 4 and 5b. Thereafter, the balloon 25 is deflated as shown in FIG. 5c by applying negative pressure to the first branch 20, and expanded as shown in FIG. 5b by applying positive pressure. The balloon 25 is pumped by applying negative pressure during its systole and positive pressure during its diastole in synchronization with its heartbeat. As a result, the balloon 25 contracts in synchronization with the beating of the heart during its systolic phase, as shown in FIG. Then, as shown in Figure 5b, the tube is tightened to force blood into the coronary artery and increase the blood flow to the coronary artery.

On the other hand, in the event of a blood vessel rupture accident or when a blood vessel is incised or severed during surgery, in order to stop the blood flow,
A balloon similar to balloon 25 shown in FIG. 4 is inserted into a blood vessel, positive pressure is supplied to the balloon, and the balloon inflates to close the blood flow path.

For example, when used to assist the heart, the balloon 25 exerts the effect of assisting the function of the living heart as described above when it is in the proper position shown in FIGS. 5a to 5C.
If the position of the balloon 25 deviates from the proper position, the above-mentioned effect may not be fully exerted, or the front end of the balloon 25 may swing and give a relatively strong stimulus to the inner wall of the aorta, causing damage. Therefore, conventionally, the tube 22, which is integrally connected to the balloon 25 and is used to supply/inhale air into the balloon 60 from outside the living body, has a scale.

When the operator pushes the balloon 25 into the living body,
The insertion length is known from the scale on the tube 22 at the insertion port of the living body, and the insertion position of the balloon 25 is estimated.

(Problem to be Solved by the Invention) However, there are individual differences in the body shape of living organisms, and whether or not the balloon 25 is actually inserted in the appropriate position can be determined by pumping the balloon 25 after insertion. Based on other biological examination information, it is determined whether or not physiological functions such as blood circulation have improved, and if they have improved, it is estimated that the balloon 25 is in an appropriate position and is operating as desired.

However, even if the physiological function improves to a certain degree, the position of the balloon 25 is not necessarily in the correct and appropriate position.
Moreover, the operation is not necessarily correct or appropriate. For example, if the balloon 25 is slightly misaligned and its leading end is oscillating, the leading end may hit or rub against the inner wall of the blood vessel, potentially damaging the blood vessel during long-term pumping. One possible method is to visually check the position and operating shape of the balloon 25 using X-ray fluoroscopy, but since it is not preferable to irradiate a living body with X-rays, MRI (Magnetic Resonance
It is preferable to visually confirm the balloon position and shape by anceImaging). However, since conventional balloons are substantially free from MR phenomena, it is difficult to recognize the position and shape by MHI.

An object of the present invention is to provide a balloon whose position and shape can be recognized by MHI.

[Structure of the invention]

(Means for Achieving the Object) The medical balloon of the present invention is composed of a flexible thin film bag (25) in which an MRI contrast agent (6) is dispersed, and has a hollow cylindrical shape when inflated. Both ends in the longitudinal axis direction are narrow in a funnel-like or spherical shape in the direction approaching the longitudinal axis, and have a small opening at the center.

(Function) According to this, the inflated shape is a hollow cylinder, and both ends of the balloon in the longitudinal axis direction are funnel-shaped or spherically thin in the direction approaching the longitudinal axis, so that the balloon can be easily inserted into the living body and When the balloon is inserted into a living body, such as a blood vessel, and inflated, its longitudinal axis is located at the center of the blood vessel, and the tip and tail ends (both ends in the longitudinal axis direction) are easily pulled out.
does not easily hit the blood vessel wall and cause damage to the blood vessel.

Furthermore, if an MRI image is taken with the balloon inserted into a living body, the image of the balloon's MRI contrast agent (6) will be cursed in the MRI image, and the MHI contrast agent (6) will appear in the flexible thin film bag (25).
6) is dispersed, the position and shape of the balloon can be recognized by visually observing the dispersed image of the MRI contrast agent (6) through MRI imaging.

In the first embodiment of the present invention, a large number of MRI contrast particles are embedded in a flexible thin film at a distance, and in the second embodiment, a large number of MRI contrast particles are embedded in a flexible thin film on the side peripheral surface of the hollow cylinder. M
Embed the RI contrast agent string.

This MHI contrast agent string is a spiral that goes around the outer circumferential surface.

Rings with a large number distributed along the longitudinal axis, or.

A straight line parallel to the longitudinal axis with many distributed in the circumferential direction. According to this, it is easy to recognize the overall position and overall shape of the balloon, and the balloon is inflated/deflated 8 times! There is no particular decline in performance.

The balloon described above is manufactured as follows. That is, the outer surface of a fusible solid having a cylindrical shape, both ends of which are narrow in a funnel-like or spherical shape in the direction approaching the longitudinal axis, and a small-diameter cylindrical protrusion along the longitudinal axis at the center thereof, is reciprocated. forming a large number of relatively shallow small holes spaced apart, or forming relatively shallow grooves distributed along the side circumferential surface of the cylinder,
The solid is immersed in a flexible thin film material solution and then pulled up to form a flexible thin film on the surface of the solid, and MHI contrast agent particles are bonded to the small holes on the surface of the flexible thin film.

Alternatively, an MRI contrast agent string is bonded to the groove, and the solid is immersed in a flexible thin film material solution and then pulled up to further form a flexible thin film on the surface of the solid.

The solid is then melted and removed from the interior of the flexible thin film.

According to this, a thin flexible thin film having a hollow cylindrical shape and having both ends in the longitudinal axis direction approaching the longitudinal axis in a funnel shape or spherical shape is easily formed on the surface of the solid, and The MRI contrast agent is easily encapsulated within the thin film thickness of the magnetic thin film. Since the solid is meltable, the solid can be easily removed to obtain a hollow flexible thin film, that is, a balloon, which has a funnel-shaped or spherical shape at both ends and a cylindrical shape between the two ends. can.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Example 1) The balloon 25 shown in FIG. 1, which shows an example of the present invention in FIG. 1a, is hollow inside like the conventional balloon. A large number of spherical protrusions 10a are distributed throughout the thin film of the balloon 25, and fat particles 6 are sealed inside the protrusions 10a.

The balloon 25 is bilaterally symmetrical and has funnel-shaped narrow ends at both ends and a cylindrical protrusion at the center.

Insert the wire 2 into the opening of the cylindrical projection at the end as shown in FIG.
The balloon 25 shown in FIG. It is incorporated into a balloon pump similar to that shown in Figure 4.

Since fat causes an MR phenomenon, MRI imaging is possible. Since the fat particles 6 are distributed over almost the entire surface of the large diameter cylindrical part of the balloon 25, by assembling the balloon 25 into a balloon pump shown in FIG. 4, inserting it into a living body, and performing MR1 imaging, Since the image of the fat grains 6 appears along the outer shape of the balloon 25 in the MRI ii image, the position and shape of the balloon 25 can be easily recognized from the MRI image.

Since the fat particles 6 are distributed discretely, the balloon 25
The swelling @/contraction function is not impaired.

Since fat is soft and highly elastic, the flexibility of the balloon 25 is not impaired, and even if the protruding part 10a touches the inner wall surface of a blood vessel, it will not be damaged, and the thin film that is the epidermis of the protruding part 10a will not be easily torn.

The balloon 25 shown in FIG. 1a is manufactured in the following manner.

(1) First, prepare a stainless steel rod l with a diameter of about 2 mm and a length of 30 cm.

(2) As shown in FIG. 2a, stainless steel 41111 is set in a silicone rubber mold 2b having a cylindrical shape 62a. The diameter of the circle 62a is 16 mm.

(3) As shown in Figure 2b, pour 3all of polyethylene glycol into the holes of mold 2b, cool and solidify.

(4) When the polyethylene glycol 3a is completely solidified, it is removed from the mold 2b.

(5) Polyethylene glycol 3 taken out from mold 2b
As shown in Fig. 2C, using a lathe or the like, shape a into a cylinder (round shape) with both ends funnel-shaped (or spherical), a small-diameter cylinder continuing in the center, and a large-diameter cylinder between both ends. The outer shape is shown by a solid line in Figure 2c).3b is processed.

(6) Using a soldering iron whose tip has been machined into a spherical shape with a radius of 2cm, as shown in Fig. 2d, a large number of dimples 4a with a depth of 1mm are applied to the entire side surface of the cylinder 3b. They are formed by being dispersed at a predetermined distance from each other. This completes the mold 3b of the balloon 25. Note that a drill may be used instead of a soldering iron.

(7) THF (jetrahydrofuran)
) 2000cc with Peresene (product name of polyurethane)
Place balloon mold 3b in polyurethane solution 5 containing 160 g.

It is immersed and then pulled out and dried as shown in Figure 2e. Drying is carried out at a temperature of 50° C. for 1 hour.

(8) Turn the balloon mold 3b upside down from the step (7) and repeat the step (7) again. In this step, the thickness of the polyurethane film on the surface of the mold 3b becomes approximately 0.02 .mu.m.

(9) A large number of fat globules 6 with a diameter of about 0.8 am (the fat globules here are those whose shape is close to a spherical shape and need not be perfectly spherical) are placed in polyurethane containing 300 cc of THF + 5 g of peresene. After soaking in the solution, as shown in Figure 2f, the balloon mold 3b after step (8) is completed.
Place it on the dimple 4b (polyurethane film formed on the dimple 4a)! ! The deposited fat globules 6 adhere to the polyurethane film formed on the dimples 4a using a polyurethane solution.

(10) Repeat steps (7) and (8) alternately three times each, and dry for at least two weeks.

(11) Balloon mold 3b after step (10) has been completed
Place it in hot water at 90°C or higher to dissolve polyethylene glycol 3b. At this time, also remove stainless steel rod 1.

(14) Take out only the polyurethane film, that is, the balloon 25, wash it with water, and dry it.

(Example 2) FIG. ib shows another embodiment of the invention.

The balloon 25 shown in FIG. 1b has a spiral protrusion 10b surrounding the large-diameter cylindrical portion of the balloon 25, and the inside of the protrusion 10b is within the thickness of the thin film.

Fatty paper 6 is enclosed in. Even in this example.

Since fat causes an MR phenomenon, MRI imaging is possible. Since the fat paper 6 is distributed over almost the entire surface of the large-diameter cylindrical portion of the balloon 25, the balloon 25 can be assembled into a balloon pump shown in FIG. 4, inserted into a living body, and subjected to MRI imaging. Since the image of the fatty paper 6 appears along the outer shape of the balloon 25 in the MR7 image, the position and shape of the balloon 25 can be easily recognized from the MRI image.

Since the fat paper 6 is distributed spirally, the inflation/deflation function of the balloon 25 is not impaired. Furthermore, since fat is soft and highly elastic, the flexibility of the balloon 25 is not impaired, and even if the protrusion 10b comes into contact with the inner wall surface of a blood vessel, for example, it will not damage it.

The thin film that is the skin of the protruding portion 10b is difficult to tear.

As a modification of the embodiment shown in FIG. 1b, the fat paper 6 may be formed into a plurality of rings distributed along the longitudinal axis of the balloon 26, or parallel to the longitudinal axis and arranged circumferentially. It may also be a number of straight lines separated by .

The balloon 25 shown in FIG. 1b is manufactured as follows.

First, steps (1) to (4) described above are performed, and in step (5), a spiral groove 4c is formed using a soldering iron, a drill, or a cutting tool, as shown in FIG. 3a.

Next, the steps (6) to (8) described above are performed, and in the step (9), the elongated linear fat, that is, the fat paper 6 is
As shown in the figure, it is placed on the bottom of the spiral groove 4d (above the polyurethane film formed on the groove 4c) and wound.

Hereinafter, steps (10) to (14) described above are performed.

〔Effect of the invention〕

According to the present invention, the inflation shape is a hollow cylinder, and both ends of the balloon in the longitudinal axis direction are funnel-shaped or spherically thin in the direction approaching the longitudinal axis, so that the balloon can be inserted into the living body and removed from the living body. It is easy to pull out, and when the balloon is inserted into a living body, such as a blood vessel, and inflated, its longitudinal axis is located at the center of the blood vessel, and its tip and tail ends (both ends in the longitudinal axis direction) touch the blood vessel wall. Yumata is less likely to damage blood vessels.

If MHI imaging is performed with the balloon inserted into a living body, the image of the MRI contrast agent (6) in the balloon will appear in the MRI image, and the MHI contrast agent (6) will appear in the flexible thin film bag (25).
are dispersed, so the position and shape of the balloon can be recognized by visually recognizing the dispersed image of the MRI contrast agent (6) through MRI imaging.

[Brief explanation of drawings]

FIG. La is a plan view showing the appearance of an embodiment of the present invention. FIG. 1b is a plan view showing the appearance of another embodiment of the present invention. FIGS. 2a and 2b are longitudinal cross-sectional views of a container for manufacturing a mold used in manufacturing the balloon 25 shown in FIGS. 1a and 1b. Figure 2c shows the balloon 2 shown in Figures 1a and 1b.
5 is a plan view showing the appearance of a mold used when manufacturing No. 5. FIG. FIG. 2d is a front view showing a state in which the surface of the mold used in manufacturing the balloon 25 shown in FIG. 1a is processed. FIG. 2e is a front view showing a step of forming a thin film on the surface of a mold in order to manufacture the balloon 25 shown in FIG. 1a. FIG. 2f is an enlarged front view showing a step of inserting fat globules 6 into dimples 4b on the surface of a mold in order to manufacture the balloon 25 shown in FIG. 1a. FIG. 3a is a front view showing how the surface of the mold used for manufacturing the balloon 25 shown in FIG. 1b is processed. FIG. 3b is a front view showing the step of winding the fat cord 6 around the spiral groove 4c on the surface of the mold in order to manufacture the balloon 25 shown in FIG. tb. FIG. 4 is a longitudinal sectional view of a balloon pump using a conventional balloon. FIG. 5a is a plan view of the living body into which the balloon has been inserted. FIG. 5b is an enlarged plan view showing the inflated state of the balloon inside the living body. FIG. 5c is an enlarged plan view showing a deflated state of the balloon inside the living body. l Stainless steel rod 2a: Hole 2b: Mold
3a = polyethylene glycol liquid 3
b: Balloon mold 4a: Dimple 4b
=Polyurethane-coated dimple 4c: Spiral groove 4d: Polyurethane-coated helical groove 5: Polyurethane solution 6: Fat globule, fat cord 10a, 10b: Projection 20:
Gas flow path 21; base body 22: tube 23: wire 24: legitimate child 25: balloon 26: bullet 60: balloon pump

Claims (5)

[Claims] (1) It is a flexible thin film bag in which an MRI contrast agent is dispersed, and its inflated shape is hollow and cylindrical, and both ends of the bag in the longitudinal axis direction are funnel-shaped or spherically narrow in the direction approaching the longitudinal axis. A medical balloon with a small opening in the center. (2) A flexible thin film whose expanded shape is hollow and cylindrical, and whose both ends in the longitudinal axis direction are funnel-shaped or spherical in shape in a direction approaching the longitudinal axis, and which has a small opening at its center; A medical balloon having a plurality of MRI contrast agent particles embedded in a thin film and spaced apart from each other. (3) A flexible thin film whose expanded shape is a hollow cylinder, whose ends in the longitudinal axis direction are narrow in a funnel-like or spherical shape in a direction approaching the longitudinal axis, and which has a small opening at its center; M embedded in the thin film in a manner distributed along the side peripheral surface of the hollow cylinder
A medical balloon having an RI contrast agent string. (4) The outer surface of a fusible solid having a cylindrical shape with both ends of the longitudinal axis narrowing in a funnel-like or spherical shape in the direction approaching the longitudinal axis and a small diameter cylindrical projection along the longitudinal axis at the center. forming a large number of relatively shallow small holes spaced apart from each other, immersing the solid in a flexible thin film material solution and pulling it up to form a flexible thin film on the surface of the solid, and forming a flexible thin film on the surface of the flexible thin film. MRI contrast agent particles are bonded to the small holes, and the solid is immersed in a flexible thin film material solution and pulled up to further form a flexible thin film on the surface of the solid, and then the solid is melted to form a flexible thin film. A method for manufacturing a medical balloon by removing a flexible thin film from inside. (5) Applicable to the outer surface of a fusible solid that is cylindrical in shape, has both ends in the longitudinal axis direction that are narrow in a funnel-like or spherical shape in the direction approaching the longitudinal axis, and has a small-diameter cylindrical protrusion in the center that runs along the longitudinal axis. Relatively shallow grooves distributed along the side circumferential surface of the cylinder are formed, and the solid is immersed in a flexible thin film material solution and then pulled up to form a flexible thin film on the surface of the solid. An MRI contrast agent string is bonded to the groove on the surface of the flexible thin film, and the solid is immersed in a flexible thin film material solution and pulled up to further form a flexible thin film on the surface of the solid. A method for manufacturing medical balloons, which involves melting and removing from the inside of a flexible thin film.