JPH02119875A - Balloon catheter and extending method for its balloon - Google Patents

Abstract

PURPOSE:To surely extend a balloon part in a direction of axial line so as to enable its outside diameter to be sufficiently thin formed by inserting a hard core material into an inner tube, providing in its point end a stopper for the hard core material to be adapted and pressing it toward the point end. CONSTITUTION:Between outer and inner tubes 9 and 7, a wire rod 16 of high rigidity in length almost equal to that of the outer tube 9 is inserted, and this wire rod 16 is fixed in its both ends respectively between the outer tube 9 and a metal ring 5 and between the tube and a plastic holder 11. When a balloon 2 is extended in a direction of axial line, a core material 1 of hard quality is inserted to the inside of the inner tube 7 of a catheter. A point end of the hard core material 1 is adapted to a stopper, provided in the inside of a point end ring 3, and stopped. Under this condition, the inner tube 7, serving as the elastic unit, is interally formed with the hard core material 1, surely extending the balloon 2. Thus enabling an outside diameter to be decreased of the balloon further smaller than in a natural condition, the balloon can be easily inserted into a fine blood vessel or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a balloon catheter whose balloon is expandable in the axial direction.

(Prior Art) In a catheter having an elastic hollow body such as a balloon, it is preferable that the outer diameter of the balloon is made as small as possible when it is deflated, and that the balloon can be expanded to a large extent when it is expanded. However, if one attempts to increase the outer diameter when expanded, there is a tendency that the outer diameter when deflated must also be increased. As a means for improving this, as shown in Japanese Patent Application Laid-Open No. 53-125388, a catheter is formed with double inner and outer tubes, and a balloon connected to each tube is extended in the axial direction by sliding the inner tube and outer tube. Accordingly, a method has been proposed to reduce the outer diameter of the balloon when deflated.

(Problem to be solved by the invention) However, in this case, since the catheter tube is soft,
There was a drawback that the balloon could not be sufficiently expanded in the axial direction.

The present invention aims to improve the drawbacks of the prior art and provides a structure and method for a catheter that can reliably extend the balloon portion in the axial direction and sufficiently reduce its outer diameter.

(Means for Solving the Problems) The balloon catheter of the present invention has an inner tube slidably inserted into an outer tube to form a catheter, and a balloon is provided at each tip of the outer tube and the inner tube of the catheter. This balloon catheter has one end and the other end connected and fixed, a hard core material inserted into the inner tube, and a stopper at the tip of the inner tube with which the hard core material comes into contact.

Further, in the balloon expansion method of the present invention, a catheter is formed by slidably inserting an inner tube into an outer tube, and one end and the other end of the balloon are respectively connected to the tips of the outer tube and the inner tube of the catheter. In a balloon catheter, the hard core material is inserted into the inner tube, and the inner tube tip is provided with a stopper against which the hard core material comes into contact, by pushing the hard core material toward the tip. , a balloon expansion method characterized by expanding the balloon.

(Example) Embodiments of the present invention will be described with reference to the drawings.

1 is a hard core material that can be separated from this catheter, and balloon 2
Insert into the catheter only when stretching. This core material 1 has enough strength to withstand the expansion resistance force of the balloon 2 when the balloon 2 is expanded. As for the material, it is effective if it is harder than the catheter, but preferably it is hard and flexible to some extent, such as elastic metal. Note that if the core material 1 is formed hollow as shown in the drawings, a guide wire can also be passed through the hollow portion.

The tip of the balloon 2 is firmly and firmly fixed to the tip ring 3 with an adhesive or a binding string 4, and the rear end is firmly fixed to the rear end ring 5 with an adhesive or a binding string 6. In order to ensure firm fixation, both rings 3.5 are preferably made of a hard and strong material, such as strong plastic or metal.

The elastic inner tube 7 is connected at its tip to the tip ring 3 with adhesive or the like, and its rear end is connected to a metal slide tube 8.
Connect with adhesive, etc.

The elastic outer tube 9 is firmly fixed to the ring 5 at the tip with an adhesive or a binding thread 10, and at the rear end is firmly fixed to a holder 11, usually made of plastic, with an adhesive or a binding thread 12. In particular, the outer tube 9 tends to have a large outer diameter, so it needs to be made soft enough to bend freely along the blood vessel, and if necessary, it is also important to make the tip part softer than other parts. It is.

An injection tube 13 for injecting gas or liquid during balloon expansion is connected to the holder 11, and in order to ensure pressure sealing of high-pressure gas or liquid and to facilitate sliding with the slide tube 8. It is composed of an O-ring 14 and a cap 15. By turning and tightening the cap 15, the strength of the contact force between the O-ring 14 and the slide tube 8 can be changed.

In the present invention, a highly rigid wire rod 16 having approximately the same length as the outer tube 9 is inserted between the outer tube 9 and the inner tube 7, and both ends of the wire rod 16 are connected to the outer tube 9, the metal ring 5, and the plastic ring. It is desirable to sandwich and fix it between the holder 11 and the holder 11.

When expanding the balloon 2 in the axial direction, a hard core material 1 is inserted inside the inner tube 7 of the catheter. The tip of the hard core material 1 hits a stopper provided inside the tip ring 3 and stops there. In this case, it is convenient that the hard core material 1 and the metal slide tube 8 can be fixed at their ends with screws, protrusions, etc.

In this state, the inner tube 7, which is an elastic body, is made of a hard core material l.
The balloon 2 is integrated with the balloon 2 to reliably expand the balloon 2. In this state, by pushing the inner tube 7 integrated with the hard core material 1 into the holder 11, the dimension shown in FIG. 1 becomes shorter, and at the same time, the balloon 2 is expanded. .

However, as the balloon 2 is expanded, a reaction force is generated that resists the expansion of the balloon, and this reaction force is transmitted to the outer tube 9 tied to the rear end of the balloon, and further to the holder 11.

The outer tube 9 is generally made of soft plastic such as vinyl chloride or polyurethane, but when a reaction force due to the expansion of the balloon acts on the outer tube 9, the outer tube 9 itself stretches. The disadvantage is that the balloon itself does not stretch much even though L is shortened.

In order to prevent the outer tube 9 from elongating, a highly rigid wire rod 16 is provided in the embodiment shown in the drawings. Highly rigid wire rod 1
6 can be selected to have such rigidity that it hardly stretches due to the reaction force associated with the expansion of the balloon 2, and at the same time, the flexibility of the outer tube 9 can be maintained.

Aramid thread, polyester thread, nylon thread, stainless steel fiber, carbon fiber, etc. can be used for the highly rigid wire 16.

(Effects of the Invention) Since the balloon catheter of the present invention can be reliably extended by a certain length, the outer diameter of the balloon can be made even smaller than in its natural state, and the balloon catheter can be easily inserted into small blood vessels. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the distal end of a balloon catheter embodying the present invention, and FIG. 2 is a sectional view of the proximal end thereof. 1 is a hard core material, 2 is a balloon, 3 is a tip ring, 4 is a binding thread, 5 is a rear end ring, 6 is a binding thread, 7 is an inner tube,
8 is a slide tube, 9 is an outer tube, 10 is a binding thread, 11 is a holder, 12 is a binding thread, 13 is an injection tube,
14 is an O-ring, 15 is a cap, and 16 is a wire rod.

Claims (3)

[Claims] (1) Form a catheter by slidably inserting an inner tube into an outer tube, and connect and fix one end and the other end of a balloon to each tip of the outer tube and inner tube of the catheter, and A balloon catheter comprising a hard core material inserted into a tube, and a stopper at the tip of the inner tube with which the hard core material comes into contact. (2) The balloon catheter according to claim (1), wherein a wire rod having higher rigidity than the outer tube is inserted between the outer tube and the inner tube, and one end of the wire rod is fixed to the distal end of the outer tube. (3) Form a catheter by slidably inserting the inner tube into the outer tube, and connect and fix one end and the other end of the balloon to the tips of the outer tube and the inner tube of the catheter, respectively, and In a balloon catheter in which a hard core material is inserted into a tube and a stopper is provided at the tip of the inner tube with which the hard core material comes into contact, the balloon is expanded by pushing the hard core material toward the tip. A balloon expansion method characterized by: