JPS5991970A - Dilating cathetel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] FIELD OF THE INVENTION The present invention relates to dilation catheters.

Such catheters are well known and widely used, for example for dilating blood vessels in angioplasty. Such catheters have a catheter shaft and an inflatable balloon adapted to be positioned near the leading end of the catheter when the catheter is inserted into a patient's body.

This leading end is commonly called the distal end.

The balloon is inflated to effect the desired dilation of the blood vessel. Once the procedure is complete, the balloon is deflated and the catheter is withdrawn from the patient's body. Traditionally, the balloons of such catheters consisted of an inflatable sleeve or ball mounted outside the shaft at or near the distal end. The balloon is inflated by filling it with fluid that flows out from inside the shaft. It is clearly desirable that the balloon not be inflated to the extent that it would cause damage to the patient's blood vessels, and one object of the present invention is to ensure that the balloon cannot inflate beyond acceptable limits and that when deflated it has a smooth surface flush with the axis. An object of the present invention is to provide a dilatation catheter having an inflatable portion or balloon having an inflatable portion or balloon. Accordingly, the present invention provides a dilatation catheter, the shaft of which comprises a tube of braided material, the tube comprising: (b) an elastic outer covering extending over a small portion of the length of the shaft at or near the distal end of the catheter, thereby making the small portion expandable; A catheter is provided. If desired, the portion of the braided tube covered with the elastic covering can be roughened (ie, reduce the number of wefts per unit length) to improve expansion properties. With the above configuration, the outer surface of the catheter is smooth over its entire length and the expandable portion can be expanded to a predetermined diameter.

For ease of description, the inflatable portion of the catheter will hereinafter be referred to as a "balloon" when the context does not indicate otherwise.

The catheter of the present invention preferably has an inner tube defining a central bore opening at each end of the catheter. This allows the catheter to be moved over the guidewire during insertion and provides a means for pressure monitoring and fluid injection. The annular space between the inner tube and the shaft of the catheter forms a passageway through which inflation fluid can be directed to inflate the balloon. The inner tube can be displaced centerline relative to the axis of the catheter to accommodate movement of the inner tube during inflation.

The present invention will be described in detail below with reference to the accompanying drawings.

In the embodiment of Figure i1, the dilatation catheter is.

It has an axis S consisting of a tube l of braided material (conveniently a polyester fibre). The main part of the outer surface of the braided tube I is covered with a coating 2 of semi-rigid inelastic material.

The material of this coating is preferably a plastic material, such as semi-rigid polyurethane or other semi-rigid plastic material, such as polyvinyl chloride (PvC) or polyethylene.

This inelastic outer covering 2 terminates near the distal end of the catheter, and the small portion where this covering is not present is covered with a covering 3 of elastic material. This elastic material can be an elastic polyurethane or other elastomeric material (eg silicone rubber). The elastic outer sheathing 3 is at the same height as the inelastic outer sheathing 2, so that the cross-sectional area of the major part and the cross-sectional area of the minor part are the same, so that the contour or the outer surface of the shaft is the same, except for the tip of the distal end. The shaft is smooth or uniform over the entire length of the shaft. Preferably, the section of the braided material which is covered with the elastic outer covering 3 is of open shape (ie the number of weft threads per unit length is smaller than in the main part of the tube 1). This allows this portion of the catheter to expand more easily than it would otherwise. The section of the braided tube further beyond this balloon can either be tightly closed to limit expansion like the main section of the braided tube, or a rigid sleeve can be placed over this section to do the same. Able to achieve purpose. An inner sheath 4 of the same or similar elastic material as the elastic outer sheath 3 is preferably bonded to the inside of the braided tube over the entire length of the catheter. A radiopaque marker portion 5a is attached to the shaft at or near the junction 1 of the two outer coverings 2 and 3. Another such marker 5b is located near the diskle end of the shaft.

It is also possible to attach the lining 6. This lining may extend over the entire length of the shaft as shown, or it may not be attached to the portion of the shaft that has the elastic outer covering 3. The material of this lining can be a fluorocarbon, such as polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene copolymer (FEP).

As shown in FIGS. 2.3 and 4, an inner tube 7 is arranged inside the shaft S. The inner tube 7 is made of a semi-rigid material, for example PVO. The inner tube 7 has the same center line as the axis S and can be displaced relative to the axis S in the direction of the center line. This inner tube 7 defines a central hole 8 with an opening 9' at the distal end. If desired, a lining (not shown) similar to the lining 6 of the embodiment of FIG. 1 can be bonded to the sheath 4 to reduce friction. The inner tube 7 is attached to the axis S by a tip or plug 10 at the distal end of the catheter, but as previously mentioned, the tube 7 can be displaced centerlineally relative to the axis S.

As shown in Figures 2 and 3, the tip 10 tapers toward the distal end of the catheter. Inner tube 7
In addition to defining the central hole 8, it also defines an outer annular hole 11. The annular hole 11 serves as an inflation hole through which fluid can pass to inflate the balloon portion of the catheter. Tip 1
0 also acts as a seal for the annular hole 11. A radiopaque marker 5b is placed at the end of the balloon.

As shown in FIG. 4, a mount is provided at the proximal end of the catheter. This mount has a rigid or semi-rigid body 13 of metal or plastic material which is attached to the outer sheath of the shaft S. An internal piston part 14 is arranged inside this body and is connected to the outside of the internal tube 7. The piston part 14 has a central passage 8a which communicates with the central bore 8 of the inner tube 7 so that the liquid can be transferred to a Luer mount at the proximal end of the passage 8a.
15 or the like into the hole 8 through an opening 15a. The liquid flows through the hole 8 and exits through the opening 9 in the digital end and enters the patient's body. The passageway 8a and hole 8 also allow pressure monitoring to be carried out during the procedure and also provide a means for inserting the catheter along the guide wire. A coil spring 16 surrounds the piston part 14 inside the body 13, supporting a shoulder 17 of the piston part and pushing it towards the distal end of the catheter. A device for preventing rotation of the piston part 14 relative to the body 13 can also be provided. A flexible seal 18 seals the annular passageway between the body 13 and the piston/14 and thus the proximal end of the annular bore 11. A luer mount 19 or other suitable connection extends laterally from the body 13 and communicates with the interior of the body so that fluid can flow into the outer annular hole 11 of the catheter to inflate the balloon portion. It becomes possible to do so.

In use, the catheter can be inserted along a previously inserted guidewire into a blood vessel of a patient undergoing treatment. Then, 1. Pull out the guide wire. The balloon portion of the catheter generates fluid pressure (conveniently generated using a suitable syringe).
Inflate by. Once the procedure is complete, the fluid pressure is lowered to allow the balloon to regain its original shape. When the fluid pressure decreases, the piston part 14 moves towards the tip lO with the help of the coil spring 16, displacing the inner tube 7 in the same direction so that the inflatable balloon part returns to its uninflated state as soon as possible. Such movement also overcomes any residual tensile stress present in the balloon portion of the catheter.

The catheter of the invention can conveniently be manufactured by braiding the tube 1 around a suitable former. (The inner coating 4 is attached to the winding form in advance.) Next, the radiopaque markers 5a and 5b are
Place. An outer sheath 3 is applied and threaded through the braid to join with the inner sheath 4. The outer coating 2 is then applied to the main part of the tube 1. The inner tube 7 and the shaft S are attached to the piston part 14 and the body 13 of the mount, respectively. 2 Then, attach the tip 10.

The catheter of the present invention can be modified for use in procedures other than angioplasty that also require dilation. In the case of a modified catheter for general dilation purposes, the catheter has an inner tube and the tip of the catheter is completely sealed.

In this variation, the proximal mount shown in FIG. 4 is not required, but a Luer mount with an integral stopper can be attached to the proximal end of the catheter to allow inflation fluid to be delivered to the catheter.

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the invention, FIG.
Figures 2 and 3 are schematic cross-sectional views of the distal end portion of a dilation catheter showing the expandable portion in a deflated state; Figures 2 and 3 are schematic cross-sectional views of the distal end portion of another catheter in a deflated and expanded state, respectively; FIG. 4 is a schematic cross-sectional view including a mount attached to the proximal end of the catheter. In the figure, S is a shaft, 1 is a tube made of braided material, 2 is an inelastic outer coating, 3 is an elastic outer coating, 4 is an elastic inner tube, 5a and 5b are radiopaque markers, 6 is an inner lining, and 7 is an inner tube. tube, 8 is the center hole, 8a is the center passage, 9 is the opening, 10 is the tip or plug, 11 is the outer annular hole, 13 is the body of the mount, 14
15 is a piston part, 15 is a luer mount, 15a is an opening, 16 is a coil spring, 17 is a shoulder of 14, 1B is a flexible seal, and 19 is a luer mount. Agent: Patent attorney Masamitsu Akizawa and one other personContinued from page 1 Priority claim @March 29, 1983 [Sir] UK (
GB) 8576 0 Inventor: Peter Henry Hannam 64, Worthing Combray, Est. Sussex, United Kingdom 0 Inventor: Neil Adrian Whiteside, Worthing Combray, Est. Sussex, United Kingdom Velvet No. 39 Showa Ta 2/July 1o Patent Office 1 U Tono 1, Incident Display 1 To Ganshoda 1 1st Dukyu 7 ``No. 2, Name of G9 θa - fmu g9cmt1 Tete 1 and 3 , Relationship with the case of the person making the amendments Address: Taiyo Building 5, 12-1 Nihonbashi Kabuto-cho, Chuo-ku, Tokyo
, Okay, 1. Hamura/Showa Month/Day (Shipping) 6, Number of inventions increased by amendment 7, Target of amendment 1 Now Qlj

Claims (1)

Claims: (1) A dilation catheter, the shaft of which comprises a tube of braided material, the tube (a) extending from a proximal end of the catheter over a major portion of the length of the shaft; (b) an elastic outer covering extending over a small portion of the length of the shaft at or near the diskle end of the catheter, thereby making the small portion expandable; A catheter characterized in that it has a coating. (2) The cross-sectional area of the main portion and the inflatable minor portion are the same, so that the contour of the shaft of the catheter is constant over the entire length of the shaft except for the tip of the disculus enr. The catheter according to item 1. (3) The catheter according to claim 2, wherein the distal end is tapered toward the distal end. (4) A device is provided at both ends (proximal end and distal end) of the catheter and in communication with the annular hole so that fluid for inflating the small portion can be supplied to the annular hole. The catheter according to any one of claims 1 to 3. (5) The catheter according to claim 4, wherein the inner tube is displaceable in the centerline direction with respect to the axis. (6) Braided material. A catheter according to any one of claims 1 to 5, wherein the tube has an inner sheath of elastic material extending over the entire length of the catheter. 7. A catheter according to any one of claims 1 to 6, wherein the catheter has an open-toothed shape over its length within the section. 8. A catheter according to any one of claims 1 to 7, wherein the catheter is disposed between the tube and the outer sheath. (9) A radiopaque marker is disposed at each end of the inflatable portion. A catheter according to any one of claims 1 to 8.00 Claims in which the distal end is fixed to the shaft inside the distal end of the shaft, and the inner tube also engages with the distal end. A catheter according to any one of paragraphs 4 to 9. A catheter according to any one of paragraphs 4 to 9, wherein the mount is attached to the proximal end of the shaft, the mount has a body fixed to the shaft, and the piston part is inside the body. disposed and secured to the inner tube of the shaft, the piston component having a passageway through which liquid can flow into or out of the inner tube, and a spring device causing the piston component to pivot. a flexible seal between the piston and the body and a connecting tube passing through the body to the annular bore for supplying inflation fluid to the annular bore; 11. A catheter according to any one of claims 4 to 10, which allows the catheter to be expanded over said small portion. (12) The catheter according to claim 11, wherein the piston part is fixed so as not to rotate relative to the main body. (13) A dilation catheter substantially as described with respect to FIG. 1 of the accompanying drawings. ■ A dilation catheter substantially as described with respect to Figures 2-4 of the accompanying drawings.