Dilation balloon - Patent Review 4906241

What is claimed is:

1. In a dilatation balloon device comprising an inflatable balloon, and a main tubular member comprising a metal tube having distal and proximal ends, said inflatable balloon disposed adjacent the distal end of said main tubular member and in fluid flow connection therewith, said main tubular member adapted for introduction of inflation fluid from its distal end into said balloon,

a distal core wire forming part of a guide wire having a proximal end portion extending into the distal end of the tube, and a distal end portion extending within said balloon to a distal termination, said wire being fixed at the distal end of the tube and having a proximal extension bridging across a fluid opening defined in the wall of the tube, the wire extension serving to transfer stress from the distal end of the device, across the fluid opening, to proximally adjacent portions of the tube, thereby to prevent stress build-up at the opening that might lead to fracture of the tube during bending of the device.

2. The dilatation balloon device of claim 1 further comprising a balloon sleeve extending proximally of an expandible portion of said balloon, across said fluid opening to a point of attachment to the tube.

3. A dilatation balloon device capable of being placed through any catheter that accepts an 0.038 inch diameter wire and capable of supporting a balloon having an inflated diameter up to about 4 mm diameter, said device comprising:

an inflatable balloon having a proximal and a distal end, said balloon being the product of the process of blowing and drawing a preformed tubular member having a tapered contour in the region corresponding to the transition section of the blown balloon,

a flexible elongated, torque transmitting hollow main tubular body of outside diameter of 0.038 inch or less, extending from a proximal region of the device to a position spaced from a distal end of the device, said inflatable balloon disposed adjacent the distal end of said main tubular member and in fluid flow connection therewith, said main tubular body having a distal portion and defining an interior volume adapted to conduct inflation liquid for said balloon,

flexible spanning structure extending distally from the fluid passage for communication between the distal portion of said main tubular body and the balloon, and including a torque-transmitting element that extends that extends from the main tubular body to a sealing formation at the distal end of the balloon,

the portion of said spanning structure that corresponds with the length of the balloon having an outer diameter no greater than about 0.025 inch, enabling the balloon to be collapsed to a profile of about 0.038 inch diameter or smaller,

the effective outer diameter of said spanning structure at said sealing formation being about 0.025 inch, to which a distal sleeve of the balloon is joined, and

a flexible, torqueable guide element extending distally from said sealing formation to the end of the device.

4. The dilatation balloon device of claim 3 wherein said hollow main tubular body includes a hollow metal tube, said torque transmitting element comprises a solid cross-section core wire joined to the distal end of said main tubular body and extending through said balloon to said sealing formation, said sealing formation including a solid annular member sealed to said wire for providing support for a distal sleeve of said balloon of substantially larger diameter than said wire.

5. The dilatation balloon device of claim 3 wherein a helical coil is joined to an outer surface of said sealing formation and extends distally therefrom to provide a flexible distal tip, the sleeve of the balloon being joined to an outer surface of said helical coil at said sealing formation.

6. The dilatation balloon device of claim 3 wherein said hollow main tubular body includes a hollow metal tube, said torque transmitting element comprises a solid cross-section core wire joined to the distal end of said main tubular body and extending through said balloon to said sealing formation, and wherein said main tubular member has a first outer diameter for most of its length and a second, reduced outer diameter portion at its distal end, the inner diameter of a region of the second, reduced outer diameter corresponding to the outer diameter of the core wire over a joint region at which said main tubular member and said solid cross-section wire are joined, said main tubular member having a fluid opening proximal of said joint region and said solid cross-section wire having a proximal portion spanning across said opening and extending proximally thereof, adapted to transfer stress from distal of said main tubular member to a portion of said main tubular member proximal of said opening, there being a flow path for inflation fluid to said opening within said main tubular member in a space defined at its inner periphery by an external surface of a proximal portion of said solid cross-section wire.

7. A dilatation balloon device comprising;

an inflatable balloon,

a flexible elongated, torque transmitting hollow metal main tubular body extending from a proximal region of the device to a position spaced substantially from a distal end of the device, said inflatable balloon disposed adjacent the distal end of said main tubular member and in fluid flow connection therewith, said main tubular body defining an interior volume adapted to conduit inflation liquid for said balloon,

flexible spanning structure extending distally from an end of said main tubular body, said spanning structure defining a fluid passage for communication between a distal portion of said main tubular body and the balloon, and including a torque-transmitting element that extends from the main tubular body to a distal end of the balloon,

said torque transmitting element comprising a solid cross-section core wire joined to a distal end of said main tubular body and extending through said balloon, said main tubular member having a first outer diameter portion for most of its length and a second, reduced outer diameter portion at its distal end, an inner diameter of the second, reduced outer diameter portion corresponding to the outer diameter of the wire over a joint region at which said member and wire are joined, said tubular member having a fluid opening proximal of said joint region and said wire having a proximal portion spanning across said opening and extending proximally thereof, adapted to transfer stress from distal of said main tubular member to a portion of said main tubular member proximal of said opening, there being a flow path for inflation fluid to said opening within said tubular main body in a space defined at its inner periphery by an external surface of a proximal portion of said core wire.

8. The dilatation balloon device of claim 6 or 7 wherein said main tubular member tapers from said first outer diameter portion to said second, reduced outer diameter portion at its distal end.

9. The dilatation balloon of claim 1, 6 or 7 wherein said wire extends to a distal tip of said device, the distal portion of said wire being of reduced diameter and more flexible relative to proximal portions thereof.

10. The dilatation balloon device of claim 1, 2, 3, 4, 5, 6 or 7 wherein helical coil means extend from the proximal region to the distal end of the device.

11. The dilatation balloon device of claim 1, 2, 3, 4, 5, 6 or 7 wherein a helical coil extends over a hollow liquid-tight tube from the proximal region of the device to the distal region of said main tubular body and a fluid impermeable sleeve extends from said distal region of said tubular body to said balloon.

12. The dilatation balloon device of claim 1, 2, 3, 4, 5, 6 or 7 wherein flexible polymeric tube means extend from the proximal region of the device to the proximal portion of said balloon.

13. The dilatation balloon of claim 1, 2, 3, 4, 5, 6 or 7 wherein said main tubular body comprises an exterior heat shrink tube shrunk upon a hollow metal liquid-conducting tube.

14. The dilatation balloon device of claim 1 or 7 wherein said balloon is the product of the process of blowing and drawing a preformed tubular member having a tapered contour in the region corresponding to the transition section of the blown balloon.

15. The dilatation balloon device of claim 14 wherein the preformed tubular member is the product of heating and drawing a defined region of an extruded tube of originally constant diameter and wall thickness.

16. The dilatation balloon device of claim 14 wherein the wall thickness of said tapering transition section is about the same as the wall thickness of the main body of the balloon.

17. The dilatation balloon catheter of claim 14 wherein the wall thickness of said tapering transition section is less than the wall thickness of the main body of the balloon.

18. The dilatation balloon catheter of claim 14 wherein the main body of said balloon has an inflated diameter of 5 mm or larger.

19. The dilatation balloon catheter of claim 14 wherein the resin from which the balloon is formed is polyethylene terephthalate.

20. The dilatation balloon device of claim 14 wherein an elongated sleeve extending proximally from said balloon past said inflation opening is formed integrally with said balloon as a result of drawing said tubular member.

21. The dilatation balloon device of claim 14 wherein said balloon has sleeves of smaller diameter than the original diameter tube from which the sleeves are formed.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

The invention relates to dilatation balloon devices which are introduced into body passageways for the purpose of dilating a collapsed portion of the passageway. In particular, the invention provides devices capable of use in balloon angioplasty.

Typically, the balloon, placed at the distal end of a flexible shaft, enters the body by means of a catheter. The balloon is then positioned in the affected region and inflated, thereby forcing the obstructed way open. The balloon may then be deflated and the device withdrawn back through a catheter and from the body.

It is advantageous for such devices to provide a small diameter profile when the balloon is deflated to allow atraumatic advance through body passageways and for positioning the balloon in the region of narrowing lesions. Angioplasty of smaller arteries, such as the coronary artery, typically requires balloons of 3 mm inflated diameter or less, which, when deflated and collapsed about a shaft, can be introduced through diagnostic catheters. For larger arteries, such as the renal artery or popliteal artery, balloons of larger inflated diameter, up to as large as 8 mm, are required for angioplasty treatment; the lesions of these arteries, however, are not necessarily larger. Larger balloons, when deflated, tend to produce larger diameter profiles, thereby inhibiting their use across narrow lesions and requiring larger diameter introduction catheters.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a dilatation balloon device comprising an inflatable balloon, and a main tubular member comprising a metal tube having distal and proximal ends, and adapted for introduction of inflation fluid from its distal end into the balloon, a distal core wire forming part of a guide wire extends into the distal end of the tube, the wire being fixed at the distal end of the tube and having a proximal extension bridging across a fluid opening defined in the wall of the tube, the wire extension serving to transfer stress from the distal end of the device, across the fluid opening, to proximally adjacent portions of the tube, thereby to prevent stress build-up at the opening that might lead to fracture of the tube during bending of the device.

In the preferred embodiment, the device further comprises a balloon sleeve extending proximally of an expandible portion of the balloon, across the fluid opening to a point of attachment to the tube.

According to another aspect of the invention, a dilatation balloon device capable of being placed through a conventional 5 French diagnostic catheter and capable of supporting a balloon having an inflated diameter up to about 8 mm diameter comprises an inflatable balloon having a proximal and a distal end, the balloon being the product of the process of blowing and drawing a preformed tubular member having a tapered contour in the region corresponding to the transition section of the blown balloon, a flexible elongated, torque transmitting hollow main tubular body of outside diameter of 0.038 inch or less, extending from a proximal region of the device to a position spaced from a distal end of the deice, the main tubular body having a distal portion and defining an interior volume adapted to conduct inflation liquid for the balloon, flexible spanning structure extending distally from the end of the main tubular body, the spanning structure defining a fluid passage for communication between the distal portion of the main tubular body and the balloon, and including a torque-transmitting element that extends from the main tubular body to a sealing formation at the distal end of the balloon, the portion of the spanning structure that corresponds with the length of the balloon having an outer diameter no greater than about 0.025 inch, enabling the balloon to be collapsed to a profile of about 0.038 inch diameter or smaller, the effective outer diameter of the spanning structure at the sealing formation being about 0.025 inch, to which a distal sleeve of the balloon is joined, and a flexible, torqueable guide element extending distally from the sealing formation to the end of the device.

Preferred embodiments of this aspect of the invention may include one or more of the following features. The hollow main tubular body includes a hollow metal tube, the torque transmitting element comprises a solid cross-section core wire joined to the distal end of the main tubular body and extending through the balloon to the sealing formation, the sealing formation including a solid annular member sealed to the wire for providinq support for a distal sleeve of the balloon of substantially larger diameter than the wire. A helical coil is joined to an outer surface of the sealing formation and extends distally therefrom to provide a flexible distal tip, the sleeve of the balloon being joined to an outer surface of the helical coil at the sealing formation. The hollow main tubular body includes a hollow metal tube, the torque transmitting element comprises a solid cross-section core wire joined to the distal end of the main tubular body and extending through the balloon to the sealing formation, and wherein the main tubular member has a first outer diameter for most of its length and a second, reduced outer diameter portion at its distal end, the inner diameter of a region of the second, reduced outer diameter corresponding to the outer diameter of the core wire over a joint region at which the main tubular member and the solid cross-section wire are joined, the main tubular member having a fluid opening proximal of the joint region and the solid cross-section wire having a proximal portion spanning across the opening and extending proximally thereof, adapted to transfer stress from distal of the main tubular member to a portion of the main tubular member proximal of the opening, there being a flow path for inflation fluid to the opening within the main tubular member in a space defined at its inner periphery by an external surface of a proximal portion of the solid cross-section wire.

According to another aspect of the invention, a dilatation balloon device comprises an inflatable balloon, a flexible elongated, torque transmitting hollow metal main tubular body extending from a proximal region of the device to a position spaced substantially from a distal end of the device, the main tubular body defining an interior volume adapted to conduct inflation liquid for the balloon, flexible spanning structure extending distally from an end of the main tubular body, the spanning structure defining a fluid passage for communication between a distal portion of the main tubular body and the balloon, and including a torque-transmitting element that extends from the main tubular body to a distal end of the balloon, the torque transmitting element comprising a solid cross-section core wire joined to a distal end of the main tubular body and extending through the balloon, the main tubular member having a first outer diameter portion for most of its length and a second, reduced outer diameter portion at its distal end, an inner diameter of the second, reduced outer diameter portion corresponding to the outer diameter of he wire over a joint region at which the member and wire are joined, the tubular member having a fluid opening proximal of the joint region and the wire having a proximal portion spanning across the opening and extending proximally thereof, adapted to transfer stress from distal of the main tubular member to a portion of the main tubular member proximal of the opening, there being a flow path for inflation fluid to the opening within the tubular main body in a space defined at its inner periphery by an external surface of a proximal portion of the core wire.

Preferred embodiments of this and the other aspects of the invention may include one or more of the following features. The main tubular member tapers from the first outer diameter portion to the second, reduced outer diameter portion at its distal end. The wire extends to a distal tip of the device, the distal portion of the wire being of reduced diameter and more flexible relative to proximal portions thereof. Helical coil means extend from the proximal region to the distal end of the device. A helical coil extends over a hollow liquid-tight tube from the proximal region of the device to the distal region of the main tubular body and a fluid impermeable sleeve extends from the distal region of the tubular body to the balloon. Flexible polymeric tube means extend from the proximal region of the device to the proximal portion of the balloon. The main tubular body comprises an exterior heat shrink tube shrunk upon a hollow metal liquid-conducting tube. The balloon is the product of the process of blowing and drawing a preformed tubular member having a tapered contour in the region corresponding to the transition section of the blown balloon. The preformed tubular member is the product of heating and drawing a defined region of an extruded tube of originally constant diameter and wall thickness. The wall thickness of the tapering transition section is about the same as the wall thickness of the main body of the balloon. The wall thickness of the tapering transition section is less than the wall thickness of the main body of the balloon. The main body of the balloon has an inflated diameter of 5 mm or larger. The resin from which the balloon is formed is polyethylene terephthalate (PET). An elongated sleeve extending proximally from the balloon past the inflation opening is formed integrally with the balloon as a result of drawing the tubular member. The balloon has sleeves of smaller diameter than the original diameter tube from which the sleeves are formed.

According to another aspect of the invention, a dilatation balloon device comprises an inflatable balloon, a main tubular member comprising a metal tube having distal and proximal ends, and adapted for introduction of inflation fluid from its distal end into the balloon, and a flexible spanning structure comprising concentric cross wound multifilar coils extending from the end of the hollow main tubular body to the distal end of the balloon.

The invention thus provides a balloon dilatation construction for a range of balloon sizes which has a minimum diameter deflated profile such that it may be introduced through a very small diameter catheter.

These and other features and advantages of the invention will be seen from the following description of a presently preferred embodiment, and from the claims.

PREFERRED EMBODIMENTS

We first briefly describe the drawings.

Drawings

FIG. 1 is a side section view of a dilatation device according to the invention having a wire coil that extends from the proximal end to the distal end of the balloon;

FIG. 2 is an enlarged partial side section view of the distal end of the metal tube used in the device, while FIG. 2a is a sectional view of the device taken at line 2a--2a of FIG. 2;

FIG. 2b is a view similar to FIG. 2 but under the condition that the dilatation device is bent, while FIG. 2c is a sectional view similar to FIG. 2a taken on line 2c--2c of FIG. 2b;

FIG. 3 is an enlarged partial side view of a bushing of the device;

FIG. 4 is a partial side section view of another embodiment of the invention in which the main wire coil terminates at the distal end of the inflation tube and a sleeve spans the structure over the core wire to the balloon;

FIG. 5 is a partial side section view of another embodiment of the invention in which a polymer shrink tubing covers the metal tube, terminating at its distal end and a sleeve spans the structure over the core wire to the balloon;

FIG. 6 is a partial side section view of another embodiment of the invention in which a cross-wound pair of multifilar coils is employed;

FIG. 7 is a diagrammatic view of an extrusion-formed tubular element of a selected resin material being heated and drawn as a step of the present invention;

FIG. 7a is a diagrammatic view of a drawn section of the tubular element;

FIG. 7b is a view similar to 7a of another form with an elongated necked-down region;

FIG. 7c is a view on a smaller scale showing the entire preform with two necked-down regions separated by a distance L;

FIG. 8 is a diagrammatic view of the preform of FIG. 7c in a position ready to be blown into a balloon;

FIG. 9 is a view similar to FIG. 8 but in cross-section showing the formed balloon;

FIG. 9a is a cross-section of the wall of the balloon of FIG. 9 showing the generally uniform wall thickness achievable along the length of the tube;

FIG. 10 is a side view of a finished balloon produced according to the invention;

FIG. 11 is a similar view of an angioplasty balloon catheter according to the invention;

FIG. 12 is a thermal analysis curve of PET resin, a material suitable for forming a device of the invention.

DETAILED DESCRIPTION

The dilatation device 10, shown in FIG. 1, has length L.sub.1, e.g. 100 cm, with a dilatation balloon 12 positioned close to the distal end. The device employs hollow metal tube 14, which extends length L.sub.2, e.g. 85 cm, in the distal direction from a strain relief 16 on a luer fitting 18. The main proximal body of tube 14 has an outer diameter d.sub.1, e.g. 0.025 inch, and an inner diameter d.sub.2, e.g. 0.021 inch. A short distal portion 20 of tube 14 is swaged to a smaller diameter, which may be seen most clearly in FIG. 2. This portion has an outer diameter d.sub.3, e.g. 0.016 inch, and an inner diameter d.sub.4, e.g. 0.011 inch, and extends for length L.sub.18, e.g. 4 mm, in the proximal direction until meeting a swaged t