WO2011146085A1

WO2011146085A1 - Rapid response balloon catheter

Info

Publication number: WO2011146085A1
Application number: PCT/US2010/056976
Authority: WO
Inventors: Allen J. Tower
Original assignee: Numed, Inc.
Priority date: 2010-05-17
Filing date: 2010-11-17
Publication date: 2011-11-24

Abstract

A rapid response balloon catheter (10) that contains a insertion tube (12) having an inflatable sheath (17) circumferentially mounted thereon which is arranged to place the balloon (21) in fluid flow communication with a fluid pump for inflating and deflating both the sheath and the balloon. When deflated the sheath and balloon assembly forms a compact tightly wrapped package that enables the insertion tube to be passed and removed easily in heretofore hard to reach body cavities.

Description

RAPID RESPONSE BALLOON CATHETER

FIELD OF THE INVENTION

[0001] This invention relates to a balloon catheter and, in particular, to a balloon catheter that employs an insertion tube having a reduced diameter and a shortened balloon inflation time.

BACKGROUND OF THE INVENTION

[0002] Most balloon catheters that are in general use today have two features that limit their utilization for use in certain procedures. The first involves the outer diameter size of the insertion tube and the other involves the length of time that is needed to inflate the balloon. The limitation that is placed on the size of the insertion tube typically depends upon the number of components that are housed within the insertion tube. One essential component is a lumen that connects the balloon to an outside pump for inflating and deflating the balloon. Minimizing the diameter of the fluid carrying lumen will extend the amount of time that is needed to inflate the balloon. In some cases, this time period can be as long as nine or more normal heart beat cycles.

[0003] Under certain conditions these relatively long inflation times can pose a danger to the patient. One such procedure concerns treating newly born infants who experience heart valve malfunction of either the pulmonary or the aortic valve. On occasion, the leaves of these multi-cusped valves can adhere one to the other or become misaligned such that the valve fails to perform normally. In some cases, the malfunction can be alleviated by inserting the balloon of a balloon catheter into the valve and inflating the balloon. Anything that can be done to shorten the time the balloon remains in the valve restricting the flow of blood will reduce the risk to the patient. SUMMARY OF THE INVENTION

[0004] It is a primary object of the present invention to improve balloon catheters.

[0005] It is a further object of the present invention to reduce the insertion shaft size of a balloon catheter to improve the ease of percutaneous insertion of the device into a body cavity;

[0006] Another object of the present invention is decrease the time required to fully inflate the balloon of a balloon catheter.

[0007] Yet another object of the present invention to reduce the risk to a patient during a procedure that involves balloon catheter.

[0008] These and other objects of the current invention are attained by means of a balloon catheter that has an elongated insertion tube that has a cylindrical inflatable sheath circumferentially mounted thereon which when inflated places the catheter balloon in fluid flow communication with a fluid pump for inflating and deflating the balloon. During insertion of the device, the sheath and balloon are deflated into a compact package about the insertion tube for ease of insertion. When the balloon is properly situated within the target area, the sheath and the balloon are inflated and the intended procedure is carried out. Upon completion, the sheath and the balloon are deflated and the catheter is removed from the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a better understanding of these and other objects of the invention, reference will be made to the following detailed description of the invention which is to be read in association with the accompanying drawings wherein:

[00010] FIG. 1 is a side elevation of the present balloon catheter showing the sheath and the balloon in a deflated condition;

[00011] FIG. 2 is a side elevation similar to Fig. 1 with portions in section showing the sheath and the balloon in a fully inflated condition; [00012] FIG. 3 is an enlarged partial side elevation in section showing the distal end of the catheter in greater detail;

[00013] FIG, 4 is an enlarged partial side elevation in section showing the proximal end of the catheter in greater detail; and

[00014] FIG. 5 is a sectional view taken along lines 5-5 in Fig. 3.

DETAILED DESCRIPTION OF THE INVENTION

[00015] Referring initially to Figs 1-4, there is illustrated a balloon catheter, generally reference 10, that embodies the present invention. The main components of the catheter are shown assembled in Figs. 1 and 2. Basically, the device includes a central elongated insertion tube 12 that forms the bases of the catheter and which can be of any desired length depending upon its intended use. The tube is preferably fabricated of a flexible material that has sufficient beam strength to enable it to be percutaneously inserted into a target region through various blood vessels, body cavities or the like by the application of an axially directed force. Tubes manufactures from various polyamide materials have shown to work well in practice. The insertion tube contains an axially extend through hole 13 for slidably containing a guide wire 15 along which the catheter can be guided into a desired target area. Here again, the size of the guide wire and the through hole can vary depending upon the specific procedure that is being carried out.

[00016] An inflatable cylindrical shaped sheath 17, that is preferably made of nylon, is circumferentially mounted over the insertion tube. The sheath, in assembly, extend longitudinally over the length of the tube between the distal end section 19 and proximal end section 20 thereof. The distal end of the insertion tube is shown in further detail in Fig. 3 in which view the sheath is illustrated in a fully inflated condition to establish a flow passage 18 between the insertion tube and the sheath. A cylindrical shaped balloon 21 is circumferentially joined to the distal open end 23 of the sheath and is bonded thereto using a heat seal 24 to produce a fluid tight joint between the two members. The balloon, like the sheath is fabricated of nylon. The opposite or distal end 25 of the balloon is similarly heat bonded to the outer surface of the insertion tube to again create a fluid tight seal 27. As will be explained in greater detail below the flow passage 18 is connected to a pump that is capable of inflating and deflating both the sheath and the balloon with a suitable fluid.

[00017] The wall thickness of the sheath is about one half that of the balloon wall thickness. It has been found that a balloon wall thickness of about 0.001" and a sheath wall thickness of about 0.0005" work quite well for most applications. The fully inflated diameter of the balloon is thus larger than that of the sheath so that the balloon and not the sheath will act upon the body tissue within the target area. As should now be evident in this arrangement the distal end of the sheath fully opens into the balloon. The volume of the flow passage is matched to that of the balloon such that the balloon can be fully inflated with the catheter's working fluid in an extremely short period of time once the fluid begins to flow through the passage established by the fully inflated sheath. As the inflation fluid moves along the inflation passage it must work to inflate and hold the sheath inflated. As a result, the fluid flow builds up energy as it approaches the balloon so that the balloon is almost instantaneously inflated as the fluid enters the balloon chamber. In terms of a patients normal heart rate, full inflation of the balloon can generally be accomplished within the time period of less than one normal heartbeat cycle.

[00018] Turning further to Fig. 4, the proximal end 20 of the catheter is shown in greater detail. Here again, the sheath is illustrated in a fully inflated condition. In the particular embodiment, the sheath contains a proximal end wall 24 that surrounds the insertion tube and which is heat bonded to the outer surface of the insertion tube to render the sheath and balloon assembly fluid tight and to provide additional stability to the assembly. A first hollow extension line 34 is passed into the sheath through the proximal end wall 24 and is removably connected by means of a snap fitting connector 37 to a syringe 38. The syringe functions in a well known manner to deliver a working fluid into the sheath and the balloon during inflation and withdraw fluid from the sheath and the balloon during deflation. [00019] A second hollow extension line 40 is also connected with the proximal end of the insertion tube. Line 40 is equipped with a wide mouth fitting 41 that serves as a means for easily directing the guide wire 15 into the through hole provided in the insertion tube. A harness 42 may also be provided for securing the two extension lines to the insertion tube portion of the catheter assembly.

[00020] Turning once again to Fig. 1 , when the sheath is in a deflated condition during insertion or removal of the catheter from a target area, both the sheath 17 and the balloon 21 are drawn into a tightly wrapped bundle about the insertion tube. The insertion package thus has an outer diameter that is only slightly larger than that of the insertion tube. As a result, the package can be easily passed through tight passages and transcend tight bends with less difficulty than most if not all the balloon catheter present known and used in the art.

[00021] Fig. 5 is a sectional view taken through the distal end of the sheath 17 looking towards the balloon 21. The sheath contains a non-deflatable raised dimple section 50 that houses a semi-circular channel 52 that extends along the entire length of the sheath. The nylon sheath may, for example, be heat treated along section 50 so that channel will not collapse with the main body of the sheath during deflation. As a result, the channel will remain open after deflation thus providing a flow path for the inflation fluid at the beginning of the inflation cycle to insure that the inflation cycle will proceed without any delays that might adversely affect the intended procedure.

[00022] A radiopaque image band 45 may be embedded in the distal end of the central tube which will aid in x-ray visual placement of the catheter during insertion.

[00023] While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof to adapt to particular situations without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims.

Claims

Claims:

1. A rapid response balloon catheter that includes:

an elongated insertion tube having a proximal end and a distal end; a cylinder inflatable sheath that is circumferentially mounted upon said insertion tube, said insertion tube extending between said proximal end and said distal end of said insertion tube, and when inflated establishes an annular flow passage between said sheath and said insertion tube;

said sheath having a first end that is bonded to said proximal end of said insertion tube and a second end that surrounds said distal end of said insertion tube;

an inflatable balloon having a proximal end that is bonded to said second end of said sheath and a distal end that is bonded to said distal end of said insertion tube, and when inflated has an inside diameter that is greater than the outside diameter of the inflated sheath; and a pump means that is connected to the first end of said sheath for introducing a fluid into said flow passage for inflating said sheath and said balloon.

2. The balloon catheter of claim 1, wherein the inflated diameter of said balloon is greater than the inflated diameter of said sheath.

3. The balloon catheter of claim 2, wherein said sheath and said balloon are both fabricated of the same material.

4. The balloon catheter of claim 3, wherein said material is nylon.

5. The balloon catheter of claim 4, wherein the wall thickness of said balloon is greater than that of said sheath.

6. The balloon catheter of claim 5, wherein the wall thickness of said balloon is about twice that of said sheath.

7. The balloon catheter of claim 1, wherein said pump means is a syringe.

8. The balloon catheter of claim 1, that further includes a radiopaque target embedded in said distal end section of said insertion tube.

9. The catheter of claim 1 , wherein said sheath contains a longitudinally extended non-inflatable stripe that houses a channel for maintaining said pump means in fluid flow communication with said balloon when said sheath is in a deflated condition.

10. The balloon catheter of claim 1, wherein said insertion tube has a lumen passing therethrough for slidably containing a guide wire.

11. A method of introducing a balloon into a body target area of a patient that includes the steps of:

providing an insertion tube having a proximal end and a distal end; circumferentially mounting a cylindrical inflatable sheath upon said insertion tube in a deflated condition which, when inflated will establish a flow passage between said sheath and said insertion tube that runs between the two ends of said insertion tube;

circumferentially mounting an inflatable balloon upon the distal end of said insertion tube in a deflated condition so that said balloon is in fluid flow communication with said flow passage;

positioning said balloon within a body target area of a patient; and delivering a fluid into said flow passage for inflating said sheath and said balloon.

12. The method of claim 11, that includes the further steps of deflating said sheath and said balloon and removing said insertion tube from said body target.

13. The method of claim 1 1, that further includes the step of providing an axially extended lumen that passes through said insertion tube and which slidably supports a guide wire within said lumen.

14. The method of claim 11, that includes the further step of fabricated said sheath and said balloon of the same material.

15. The method of claim 1 1, that includes the further step of fabricating said sheath and said balloon of nylon.