US-12616819-B2 - Controllable inflation profile balloon cover methods

Abstract

A method of inflating a catheter balloon may include providing a balloon assembly operable to provide a balloon diameter vs. balloon pressure profile generally depicting a balloon inflation sequence providing at least one intermediate inflated diameter and a final inflated diameter of a balloon such that the balloon attains the at least one intermediate diameter at a predetermined pressure, and attains the final diameter at a final predetermined pressure that is lower than a predetermined pressure of a last intermediate pressure.

Inventors

• Carey V. Campbell
• James L. Goepfrich
• BRANDON C. HEDBERG
• Benjamin M. Trapp

Assignees

• W. L. GORE & ASSOCIATES, INC.

Dates

Publication Date

20260505

Application Date

20211015

Claims (19)

1. 1 . A catheter balloon assembly comprising: an inflatable balloon having a balloon body portion defining a balloon working length and an un-inflated diameter and a working diameter; and a frangible cover covering at least a portion of the balloon body portion and being operable such that the inflatable balloon having a balloon diameter vs. balloon pressure profile in which a diameter of the inflatable balloon is controllable according to an applied inflation pressure, the balloon diameter vs. balloon pressure profile including a beginning diameter at an initial applied inflation pressure and a working diameter at a final predetermined pressure, wherein a first intermediate inflated diameter and the working diameter of a balloon are defined, and wherein the inflatable balloon attains the first intermediate inflated diameter at a first predetermined pressure, and attains the working diameter at the final predetermined pressure that is lower than the first predetermined pressure, and the frangible cover being operable to rupture under an internal pressure before the rupture of the balloon.
2. 2 . The catheter balloon assembly of claim 1 , wherein the frangible cover is operable to control the balloon to open to an intermediate length that is less than the working length.
3. 3 . The catheter balloon assembly of claim 1 , further comprising a plurality of frangible covers each being operable to control the balloon to open sequentially to a different larger intermediate diameter that is smaller than the working diameter.
4. 4 . The catheter balloon assembly of claim 1 , wherein the frangible cover is operable to allow the balloon to have a substantially uniform diameter long the working length of the balloon.
5. 5 . The catheter balloon assembly of claim 1 , wherein the balloon increases in diameter substantially uniformly along the working length of the balloon after the rupture of the frangible cover.
6. 6 . The catheter balloon assembly of claim 1 , further comprising: an outer cover covering at least a substantial portion of the frangible cover operable to contain the frangible cover once the frangible cover ruptures.
7. 7 . The catheter balloon assembly of claim 6 , the balloon comprising two opposed balloon leg portions that are each integrally connected to a balloon taper portion, with each of the balloon taper portions connected to the balloon body portion therebetween, the balloon working length defined as the length of the balloon body portion of the balloon that comprises an approximate length between opposed balloon taper portions; further comprising the balloon cover comprising: a first legged cover portion including a first cover body portion integrally connected to a first cover taper portion, further including a first cover leg portion located at an apex of the first cover taper portion, the first cover body portion being operable to overlay a portion of the balloon body portion, the first cover taper portion being operable to overlay a portion of one of the balloon taper portions, the first cover leg portion being operable to allow one of the two opposed balloon leg portions to pass through; and a second legged cover portion including a second cover body portion integrally connected to a second cover taper portion, further including a second cover leg portion located at an apex of the second cover taper portion the second cover body portion being operable to overlay a portion of the balloon body portion, the second cover taper portion being operable to overlay a portion of the other of the balloon taper portions, the second cover leg portion being operable to allow another one of the two opposed balloon leg portions to pass through, the first cover taper portion and the second cover taper portion are located at opposite ends of the balloon cover, the first legged cover portion and the legged second cover portion are coaxially aligned and overlay the balloon such that at least a portion of the first cover body portion overlays at least a portion of the second cover body portion, the frangible cover overlaying the first cover body portion, the second cover body portion, and at least a portion of each of the first cover taper portion and the second cover taper portion, the outer cover covers the frangible cover and is coupled to the first cover leg portion and the second cover leg portion.
8. 8 . The catheter balloon assembly of claim 7 , wherein the balloon cover comprises a fibrillated material.
9. 9 . The catheter balloon assembly of claim 8 , wherein the fibrillated material is ePTFE.
10. 10 . The catheter balloon assembly of claim 9 , wherein fibrils in said ePTFE are oriented in a radial direction.
11. 11 . The catheter balloon assembly of claim 7 , wherein the balloon cover is made from strips of ePTFE that are adhered to each other.
12. 12 . The catheter balloon assembly of claim 11 , wherein the strips are laid in multiple angular orientations on the working length of the balloon and the first cover taper portion and second cover taper portion.
13. 13 . The catheter balloon assembly of claim 7 , wherein the balloon cover is adhered to the balloon.
14. 14 . The catheter balloon assembly of claim 7 , wherein the first and second cover body portions that overlap for a substantial portion of the balloon body portion also cover a portion of balloon taper portion.
15. 15 . The catheter balloon assembly of claim 7 , wherein a working diameter of the balloon cover is smaller than the working diameter of the balloon.
16. 16 . The catheter balloon assembly of claim 1 , wherein the balloon is a compliant balloon.
17. 17 . The catheter balloon assembly of claim 1 , wherein the balloon is a non-compliant balloon.
18. 18 . A method of making the catheter balloon assembly of claim 1 , comprising: covering at least a substantial portion of the frangible cover with an outer cover, the outer cover operable to contain the frangible cover once the frangible cover ruptures during use.
19. 19 . The method of claim 18 , further comprising providing a second frangible cover operable to control the balloon to inflate to a second intermediate inflated diameter, wherein the second intermediate inflated diameter is smaller than the maximum inflated diameter.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. Patent Application Ser. No. 16/017,265, filed Jun. 25, 2018, now U.S. Pat. No. 11,173,286, issued Nov. 16, 2021, which is a continuation application of U.S. Patent Application Ser. No. 13/619,806 filed Sep. 14, 2012, now U.S. Pat. No. 10,016,579, issued Jul. 10, 2018, which is a Continuation-In-Part U.S. Patent Application Ser. No. 13/529,896 filed Jun. 21, 2012, now U.S. Pat. No. 9,370,643, issued Jun. 21, 2016, which claims priority to U.S. Provisional Patent Application No. 61/500,555 filed Jun. 23, 2011, and also claims priority to U.S. Provisional Patent Application No. 61/535,864 filed Sep. 16, 2011. FIELD This disclosure relates generally to a medical device, and more particularly to apparatus and a methods providing a low profile medical balloon with controllable inflation profile. BACKGROUND Balloon angioplasty is a widely used procedure for expanding constricted body passageways, such as arteries and other blood vessels. In an angioplasty procedure, an un-inflated balloon attached to a catheter is delivered to a constricted region of a body passageway. Once the balloon is in position at the constricted region, fluid is injected through a lumen of the catheter and into the balloon. The balloon consequently inflates and exerts pressure against the constricted region to expand the passageway. After use, the balloon is collapsed, and the catheter is withdrawn. Balloons have a number of critical design parameters. One is rated burst pressure, which is the statistically-determined maximum pressure to which a balloon may be inflated without rupturing. In order to expand hard, calcified lesions, it is desirable that the balloon have a relatively high rated burst pressure. It is also desirable that the balloon have a low wall thickness to minimize the profile of the delivery system when the balloon is in a deflated state. For a given balloon material, however, there is a trade-off between burst pressure and wall thickness, in that the burst pressure generally decreases when the wall thickness is reduced. Accordingly, there is a need for increasing the strength of a balloon to attain a higher rated burst pressure while maintaining a low delivery profile. Balloons used for stent delivery have the added requirement of delivering a stent in a controlled manner. Balloons with a large difference in their deflated profile (deflated diameter) and their expanded profile (expanded diameter) commonly inflate in an uneven manner along the length of the balloon. By way of example, one end of the balloon may attain an expanded diameter prior to the opposing end, or the middle of the balloon may expand prior to the ends. This inconsistency of inflation increases the likelihood that the stent will be dislodged longitudinally along the length of the balloon moving either partially or fully off the balloon. The inconsistency of inflation profile increases the likelihood for vessel trauma as the stent is unevenly expanded and subsequently unevenly engages the vessel wall. Accordingly, there is a need in the art for a balloon system that provides for the control of the inflation profile to provide a uniform profile along the length of the balloon as the system is inflated to reduce the risk of stent misalignment/dislodgement and vessel trauma. Doctors are also commonly faced with a decision pertaining to what diameter stent/balloon system to choose for delivery. Accuracy in measurement technique and the choices in device diameter often limit the doctor's ability to choose a balloon/stent system that is optimally sized for the intended vasculature. Accordingly, there is a need for a balloon that provides one or more intermediate inflated diameters that are apparent to the doctor during delivery that provides a uniform profile (that is, a relatively uniform diameter) along the length of the balloon at each intermediate diameter. SUMMARY An embodiment comprises a catheter balloon having a working length and an expanded and an unexpanded diameter. At least partially surrounding the balloon is a balloon cover having a length and an expanded and unexpanded diameter. Wherein said balloon cover comprises first and second portions, wherein said first and second portions each comprise a working length integrally connected to a taper end having an aperture located at an apex of the taper end and said taper ends of said first and second portions are located at opposite ends of said balloon cover and said first and second working lengths of the first and second cover portions overlap for a substantial portion of the balloon working length. Another embodiment comprises a balloon cover having a length, an unexpanded and expanded diameter, and first and second portions, wherein said first and second portions each comprise a working length integrally connected to a taper end having an aperture located at an apex of the taper end, and wherein said taper ends of