JPS6141216B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device used to dilate occluded blood vessels. The invention is particularly achieved with a balloon element that is initially everted within the distal end of the catheter, but which, during use, is forced through and expanded within the occlusion being treated. The present invention is contemplated for use in treating both arterial and venous occlusions.

Prior art efforts in treating occluded blood vessels have relied primarily on the use of bypass vessels or some type of surgical technique to remove the obstruction from the vessel being treated. Other current techniques for treating occluded blood vessels rely on the insertion of certain types of instruments into the blood vessel to dilate the occlusion by methods of stretching or compression. The present invention relates to the latter type of technique.

A primary problem with the use of techniques for inserting instruments into blood vessels to achieve dilation by compression or stretching is that the instruments may damage and/or dislodge material from the blood vessel. Another problem with this type of technique is that the instruments used for this purpose have been extremely difficult to place in highly occluded or small diameter vessels.
These problems arise primarily from the construction and size of the device. In one such technique,
The device is in the form of progressively larger catheters that are successively pushed through the blood vessels being treated. In other techniques, the device is in the form of an inflatable catheter that is pushed into position within the occlusion area to be treated and expanded once in place. Although these prior art catheters are flexible, they are necessarily somewhat rigid and inelastic so that the catheter can be advanced a significant distance through the arterial or venous system. The inherent stiffness of these catheters contributes to the vessel damage and material removal problems discussed above.

The present invention relies on a device in which a highly flexible balloon is everted within the distal end of a flexible catheter and everted from the catheter to push it through the occluded portion of the treated blood vessel. The balloon and catheter are designed so that the balloon everts from the catheter and is forced through the occlusion before the balloon's lateral sides expand significantly.
Eversion of the balloon from the catheter is accomplished by applying internal fluid pressure to the catheter. After the balloon is placed in position within the occlusion of the blood vessel, subsequent application of fluid pressure causes the balloon to expand laterally and dilate the occlusion. This method of expanding the balloon laterally to dilate the occlusion produces pulsations due to repeated increases and decreases in fluid pressure within the catheter. In a preferred embodiment of the invention, a cord element extends through the catheter and is connected to the balloon for inverting the balloon into the catheter after the occlusion has been treated.

A first object of the invention is to provide a device that can be used to dilate a blockage in an artery or vein without causing damage to the vessel being treated or removing material from the blockage. .

The present invention allows the soft, expandable dilation section to be gently advanced through the occluded area, without the need to force a stiff catheter through the occluded area prior to dilation, dilating the occluded artery or vein. can do.

According to a preferred embodiment of the invention, a mechanism is included within the catheter for retracting and everting the expandable element after expansion. This retraction everting mechanism allows a secondary catheter to extend through the primary catheter and the expandable element to allow pressure measurements and injections without the need to remove the catheter from the vessel being treated. Contains.

The present invention allows dilation of selected and limited areas within the blood vessel being treated.

The catheter body can have a smaller diameter than the lumen of the blood vessel being treated and the expandable element can initially evert into the distal end of the catheter. The occlusion can be pushed into position within the occluded portion of the vessel being treated without significant disturbance, and once in place, the occlusion can be repeatedly subjected to pulsatile dilation. It can be laterally inflated or deflated.

These and other objects will become apparent from the following detailed description with reference to the accompanying drawings.

DESCRIPTION OF THE FIRST EMBODIMENT FIG. 1 shows a blood vessel 10 partially occluded by an occlusion object 12. As shown, the blood vessel is in the form of an artery and the obstruction is what is commonly known as arteriosclerosis or arterial atheroma. This is the type of deposited obstruction to which the apparatus and method of the present invention are expected to be applied in the first place. However, it should be understood that the present invention is applicable to treating other types of occluded blood vessels in which dilation is desired. For example, the invention can be used to treat occlusions resulting from impaired intravenous muscle fiber formation.

The principal elements of the first embodiment of the device illustrated in this FIG. A balloon element made of a resilient resilient material, such as latex, having a mouth portion (attachment shoulder) 18 secured circumferentially to the distal end of the catheter 14 and initially everted within the catheter. a balloon element 16 having a body portion 20; a cord 22 extending through the catheter 14 and connected to one end of the body portion 20 of said balloon element; and proximate access of the catheter 14 via an intermediate tubular joint 26; A syringe 24 connected to the end has a cinder 28 in which a positive displacement piston plunger 30 is sealingly and slidably fitted, said plunger being connected to the cord 2.
a syringe connected to the proximal end of the fitting 2;
a tubular lateral extension 34 formed as part of 6;
a flexible storage tank 32 removably connected in fluid communication with the interior of the joint 26;
and a selectively actuatable shut-off valve 36 inserted within the extension 34. The length of this catheter can be changed depending on the intended use.
Its length is usually up to 76 cm. The transverse dimensions of the catheter can vary depending on the intended use and are generally selected such that the outer diameter of the catheter is equal to about one-half the inner diameter of the unobstructed lumen of the vessel being treated. be done. In one exemplary embodiment, the catheter and associated balloon element have the following dimensions.

Catheter body dimensions Outer diameter: 2.16 mm Inner diameter: 1.52 mm Length: Can vary up to approximately 762 mm Dimensions of balloon element when separated from catheter Outer diameter of reduced diameter body: 0.864 mm Inner diameter of reduced diameter body: 0.51 mm Thickness of reduced diameter body: 0.178mm Outer diameter of mounting shoulder: 3.56mm Thickness of mounting shoulder: 0.178mm Length of mounting shoulder: 6.60mm Dimensions of attached balloon Uninflated and turned over Length: 5.08mm After eversion Inflation Length: 17.78mm Inflation Outer Diameter: 4.06mm In this preferred embodiment, the length, wall thickness, and outer diameter of the balloon element are such that when the element is abducted symmetrically from the catheter, Designed to prevent it from dragging on the inner wall of the building. This balloon element should ideally have a length not exceeding about 25 times the inner diameter of the catheter.

The material and relative thickness of the balloon element are such that inflation of the balloon element from the end of the catheter occurs in an anisotropic manner such that the element first everts out of the catheter before appreciable lateral expansion and then After eversion, the catheter is selected to expand laterally in response to subsequent application of fluid pressure to the interior of the catheter.
Immediately after eversion from the catheter, the balloon element is designed to inflate laterally to an outer diameter equal to or greater than the inner diameter of the undilated vessel being treated. Although this feature can be achieved through the use of an elastomeric balloon element, such as in the example above, a similar feature can be achieved by first eversing to an extended state and then opening laterally to an inflated state. This is expected to be accomplished by making the balloon element from a flexible material that is folded and generally inelastic.

The cord 22 is flexible and generally non-resilient and is capable of retaining the balloon element 16 when moved from the inverted condition shown in FIG. 2 to the extended condition shown in FIG. It has a length that does not restrict abduction. To enable such unrestricted elongation of the balloon element, the cord ideally includes a slack portion as shown in the cylinder 28 illustrated in FIG. However, this cord also has a defined length such that upon retraction of plunger 30 beyond a predetermined limit, the balloon element is retracted and everted into the distal end of the catheter, as illustrated in FIG. Should.

Catheter 14, syringe 24, and reservoir 32 contain an incompressible fluid F. Preferably, this fluid is radiopaque to facilitate radiofluoroscopic monitoring of catheter position and progress of the dilation procedure. Valve 3
6 is provided so that this fluid can be selectively trapped between the balloon element 16 and the piston 30 (if this valve is closed) or loaded into the reservoir 32 and drained ( if the valve is open). In either situation, however, reservoir 32 ensures that catheter 14 is always filled with fluid. Prior to the expansion phase, the catheter and reservoir are evacuated and filled with fluid. The reservoir is separated from the catheter, the parts are packed separately, and the reservoir and catheter are reattached. Fourth
When the valve is in the open position as shown, the piston plunger 30 is retracted to tension the cord 22 and thus draw the balloon element 16 into the catheter again in the everted position. Dew. If valve 36 is occluded, piston plunger 30 will be compressed and apply internal pressure to the catheter, thus everting the balloon element from the end of the catheter as illustrated in FIG. In the preferred manner of operation, the piston plunger 30 expands the balloon element in a well-controlled manner upon depression of the plunger and ensures that the cord 22 remains loose throughout the eversion of the balloon element from the catheter. As a break-in, the valve 36 is depressed to a predetermined degree prior to closing. Appropriate markings can be provided on the surface of the syringe 24 to indicate the point of the plunger stroke at which the valve 36 is to be closed.
The preferred construction also includes a shoulder 37 on the plunger 30 for abutting the end of the cylinder to limit inward movement of the plunger.

In using this first embodiment of the catheter in practicing the method of the present invention, an incision is first made within the blood vessel on one side of the occlusion to be treated, and then the distal end of catheter 14 is opened. It is introduced into this blood vessel through the above incision. The catheter is then delivered through the blood vessel to position its distal end adjacent one end of the occlusion as illustrated in FIGS. 1 and 2. At this point or prior to this point, the plunger 3
The zero position is adjusted and valve 36 is closed. With the catheter positioned as described above and the plunger conditioned as described above, the next step is to apply pressure to the plunger as illustrated in FIG. 3 to subject the catheter to internal fluid pressure and occlude it. The body portion of the balloon element is everted from the catheter to force it through section 12. In this preferred manner, in the outer axis, the balloon element extends axially without substantial lateral expansion. The balloon element is the blockage part 1
2, subsequent application of fluid to the catheter through plunger 30 causes the balloon element to expand laterally, as illustrated in FIG. 4, thus forcing the occlusion apart. It acts on By moving the plunger 30 in and out, such expansion and expansion are performed in a pulsating manner. The progress of the procedure can be monitored fluoroscopically throughout the deployment and expansion process. As a result of the lateral expansion of the balloon element, the amount of elongation during this expansion process will vary somewhat depending on the circumstances involved. Ideally, the balloon is expanded to have an outer diameter equal to or slightly larger than the inner diameter of the unoccluded blood vessel.

Immediately after inflation is complete, valve 36 is opened and plunger 30 is retracted as shown in FIG. 5 to tension cord 22 and thus re-invert the balloon element within the catheter. . At this point, the catheter can be removed from the blood vessel and the incision introduced through the catheter can be closed. Depending on the circumstances involved, it is also possible for the catheter to be moved into further parts of the occlusion being treated or over a continuous occlusion prior to removal of the catheter. In such a case, after each successive dilatation procedure, the balloon element is everted and re-expanded, thus ultimately retracting and everting the balloon element and removing the catheter from the blood vessel. be done.

DESCRIPTION OF THE SECOND EMBODIMENT The embodiment of FIG. 6 is such that the balloon element, designated 16a, is retracted back into an everted position within the catheter, designated 14a. This corresponds to the first embodiment except that it does not include a code. Other than this difference, the structure and manner of operation of the embodiment illustrated in FIG. 6 is identical to that of the first embodiment described in the foregoing description of the figures in FIGS. Will. In the embodiment of FIG. 6, retraction and everting is accomplished by the vacuum created within catheter 14a by retraction of the plunger of a syringe (not shown) associated with catheter 14a. It is also possible that the balloon element of FIG. 6 is expanded during removal of the catheter after the expansion process, but held in a terminally inflated state. After catheter 14a is removed from the vessel being treated, external devices can be used to assist in retracting and everting the balloon element.

DESCRIPTION OF THE THIRD EMBODIMENT The third embodiment illustrated in the figures from FIGS. 7 to 10 and described in the foregoing description with respect to the figures from FIGS. The main difference between this third embodiment and the first embodiment is that this third embodiment uses an annular balloon element 16b instead of a closed bulbous element 16.
and a tubular cord element in the form of a flexible catheter 22b instead of a simple cord 22. The purpose of these differences is that the passageway used to measure the pressure within the vessel being treated or used for injection into the vessel (i.e., the passageway through catheter 22b and annular balloon element 16b) can be provided. For the latter purpose, plunger 30b (FIG. 7) is provided with a passageway through which catheter 22b extends and a syringe 38 is connected to the proximal end of catheter 22b.

The blood vessels and occlusions depicted in Figures 7 to 10 correspond to those depicted in Figures 1 to 5, and are therefore designated by the numbers 10 and 12, respectively. It is shown. Elements of the catheter and inflation mechanism of the third embodiment that correspond to those of the first embodiment are shown below in FIGS. 7 to 10 with numerals corresponding to those used in FIGS. 1 to 5. Shown as: catheter 14; syringe 24; tubular fitting 26; cylinder 28; flexible reservoir 32; tubular lateral extension 34; and shutoff valve 36.

The mouth part (mounting shoulder part) of element 16b is numbered 18.
b and the body portion of element 16b is designated 20
It is shown in b. Inner catheter 22b, to which balloon element 16b is attached, may be made of any suitable material, such as Dacron or polyvinyl chloride. Ideally, the material from which catheter 22b is made is flexible and generally inelastic.

Similar to the balloon element 16, an annular balloon element 16b
is abducted from the end of the catheter 14 in an anisotropic manner such that the balloon element first abducts from the catheter before appreciable lateral expansion, and then after abduction, the balloon element abducts from the catheter 14.
is configured to be able to expand laterally in response to subsequent application of fluid pressure to the interior of the tube. Catheter 22b acts similar to cord 22 and should be flexible and generally inelastic, and should have a length that does not control eversion of balloon element 16b from catheter 14. It is. Non-limiting element 1 above
Catheter 22b ideally has slack as shown in cylinder 28 in FIG. 7 to allow extension of catheter 22b. However, catheter 2
2b also includes plunger 3 beyond the predetermined limit.
The retraction of element 16b is of such length that it serves to re-invert element 16b into the distal end of catheter 14 as shown in FIG.

The catheter 14, syringe 24, and reservoir 32 of the third embodiment contain an incompressible fluid F and cooperate with the valve 36 in a manner similar to that described in the foregoing description of the first embodiment. It works the same way.
In order to limit the inward movement of plunger 30b with respect to cylinder 28, a stop shoulder 37b corresponding to said shoulder 37 is provided on plunger 30b.

The catheter of this third embodiment is used to carry out the method of the invention essentially in exactly the same manner as described in the foregoing description of the first embodiment. During this use, an incision is first made in the blood vessel on one side of the occlusion to be treated, and then the distal end of catheter 14 is introduced into the blood vessel through the incision. The catheter is then advanced through the blood vessel to a position proximate one end of the occlusion, and after being positioned as described above, plunger 3
0b is used to first insert said element into catheter 14.
abduction from and through the occlusion, then expanding element 16b laterally to dilate the occlusion.
As with the catheter of the first embodiment, element 16b is forced through the occlusion prior to significant lateral expansion of the element. Enlargement of the element for dilation purposes can be pulsed by moving plunger 30b in and out and the progress of dilation can be monitored with fluoroscopy. The extent of expansion during the expansion method may vary somewhat depending on the circumstances involved. Generally, element 16b is expanded to have an outer diameter equal to or slightly larger than the inside of the unoccluded portion of the vessel being treated.

7, 8, 9 and 10 depict successive steps in implementing the invention.
FIG. 8 shows the catheter when element 16b is initially expanded for push through the occlusion. From this view it can be seen that catheter 22b is connected to element 16.
element 16b is passed through the occlusion along with element 16b.
It will be seen that it provides a passage through the . 9th
The figure shows element 16b when expanded to dilate occlusion 12. In Figure 10, valve 3
6 is opened and plunger 30b is retracted to pull catheter 22b, thus element 16
b is shown inverted again within the catheter 14. If element 16b is everted again as described above, the catheter can be moved to another location within the blood vessel for another dilation procedure or removed from the blood vessel.

The lumen of the catheter 22b provides a device for accomplishing injections or pressure measurements while the third embodiment catheter 14 is in place within the blood vessel. Such injections or measurements can be made at any time since the lumen of catheter 22b remains open at all times.

Although the present invention has been described above in detail with reference to preferred embodiments, it is of course possible to make various changes without departing from the spirit and scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an occluded blood vessel in the process of being treated in accordance with a first embodiment of the invention, with a portion of the blood vessel torn away and shown in cross section; FIG. FIG. 3 is a cross-sectional side view showing the catheter as it is introduced into the occluded portion of the blood vessel and the blood vessel being treated; FIG. FIG. 4 is a cross-sectional side view similar to FIG. 2 showing the catheter of the first embodiment and its associated vessel being treated; FIG. A cross-sectional side view similar to FIG. 3 showing the expandable element after inflation; FIG. 5 shows the expandable element immediately after completion of the expansion procedure and re-inversion of the element into the catheter 6 shows in solid lines the inflatable element in an everted position and in dashed lines the inflatable element in the progressive stages of eversion and lateral expansion. Indicated. FIG. 7 is a cross-sectional side view of a second embodiment of a catheter, and FIG. FIG. 8 is a cross-sectional side view with dashed lines representative of a blood vessel; FIG. 7 showing the vessel being treated; FIG. 9 showing the expandable element of the third embodiment after dilating the occlusion being treated; FIG. A side view in cross-section similar to FIG. 8, FIG.
An example of an inflatable element is shown. 9 is a side view in section similar to FIG. 9; FIG. 10... Blood vessel; 12... Occlusion part; 14... Catheter; 16... Balloon element; 22... Cord; 2
4...Syringe; 26...Middle tubular joint; 28...
...Cylinder; 30...Piston plunger; 32
... flexible reservoir; 34 ... tubular lateral extension; 3
6... Shutoff valve.

Claims (1)

[Claims] 1. A device for dilating a partially occluded part of a blood vessel, which includes a long and thin flexible catheter that can move freely within the blood vessel, and a balloon device that is placed upside down inside the catheter. The catheter has a mouth that is tightly fitted around the distal end of the catheter and is adapted to be pushed through the occluded portion of the blood vessel prior to everting out of the catheter and appreciable lateral expansion. The occlusion is capable of flipping out of the catheter in response to application of fluid pressure and, after flipping back out of the catheter, in response to subsequent application of fluid pressure inside the catheter. a balloon device laterally expandable to an outer diameter sufficiently large to at least partially expand the catheter; and a device for selectively applying internal pressure to the catheter.