The present invention relates to medical devices and more particularly to a cutting balloon device for expanding passageways in the venous system.
One of the most common heart diseases in industrialized countries is atherosclerotic cardiovascular disease, caused by the buildup of plaque or stenoses in the blood vessels. This affliction affects not only veins or arteries, but also dialysis access systems such as fistulas or grafts. Generally, arteries are susceptible to the buildup of plaque. The venous system, however, has lesions that are generally fibrous in nature, usually in the form of scar tissue or venous valvular rings. Additionally, when there is long term placement of a fistula or graft, there is a tendency for the passageway to narrow. The venous anastomosis of a graft, which may be made from PTFE or some other suitable material, may develop a different lesion, such as fibro-muscular hyperplasia. All three of these inflictions are distinct in their nature; however, they all generally respond well to balloon dilation or angioplasty.
There are numerous inventions that have attempted to successfully expand venous passageways that have been narrowed by plaque or stenoses. One of the most well known is the “Fogarty catheter,” which is described in detail in U.S. Pat. No. 3,435,826 (the '826 patent) to Fogarty, as well as U.S. Pat. No. 4,403,612 (the '612 patent). Both the '826 patent and the '612 patent describe inflatable balloon catheters. The balloon catheter of the '826 patent comprises a catheter having an inflatable balloon at its distal tip. The balloon catheter of the '826 patent is operated by inserting the deflated balloon catheter into the vessel beyond the clogged portion, inflating the balloon and then pulling the inflated balloon towards the clogged area, thereby dislodging the clog and dragging the blockage to an incision where the clog can be removed. The balloon catheter of the '612 patent has two balloons, wherein a first balloon is disposed inside of a second balloon and both the first and second balloon are located at the distal tip of a catheter. In use, the balloon catheter of the '612 patent is inflated and compresses the plaque or stenoses that is located along the wall of a vessel, thereby enlarging the venous passageway.
Most types of inflatable balloon catheters expand the vessel by exerting pressure on the buildup located on the walls of the vessel and squeezing the buildup against the vessel wall. There are other types of balloon catheters that do not inflate; rather, they expand using some other mechanical process. An example of this type of mechanically expanding balloon catheter is described in detail in U.S. Pat. No. 4,921,484 to Hillstead (the '484 patent). The '484 patent describes a catheter having a woven mesh balloon at its distal tip. During insertion, the balloon is elongated and maintains a narrow profile. When the balloon reaches the vessel to be expanded, the distal tip of the catheter is contracted, thereby expanding the woven mesh balloon. The expanded mesh balloon is then used to break through or scrape plaque and stenoses, thereby expanding the vessel.
It would be beneficial to provide a device for removing plaque and stenoses from dialysis accesses such as fistulas or grafts, as well as blood vessels that may be clogged, that is inflatable through the injection of a fluid into the center of the balloon and also has the surface characteristics of a mesh balloon.
The present invention is a cutting balloon catheter assembly including a dual lumen catheter having an inflatable balloon at its distal end having an interior cavity and an expandable covering disposed about the balloon, wherein the covering has an array of cutting edges. In the assembly, the balloon is fixedly connected to the distal end of the catheter and the interior cavity of the balloon is in fluid communication with an inflation/deflation lumen of the catheter.
The invention further includes a method of removing obstructions from vessel walls using the cutting balloon catheter, wherein after catheter insertion and balloon inflation, the assembly is reciprocally moved either axially or rotationally, such that the array of cutting edges abrades the stenoses, plaque or lesions along the vessel wall.
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention. In the drawings:
a is an enlarged sectional view of an alternative embodiment of a cutting balloon catheter assembly;
In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The words “proximal” and “distal” refer to directions away from and closer to, respectively, the tip of the double lumen catheter assembly that makes up a portion of the cutting balloon assembly according to the present invention. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The following describes preferred embodiments of the invention. However, it should be understood based on this disclosure, that the invention is not limited by the preferred embodiments described herein.
Referring to
A distal tip 144 is located at the distal end 134 of the catheter 130, at a point that is distal of the balloon 120. Preferably, the distal tip 144 is rounded to facilitate smooth insertion of the assembly 100 into a patient's blood vessel. The distal tip 144 preferably is radiopaque for precision location at a site using known imaging techniques and has a distal passageway 146 that is in fluid communication with the axial lumen 136, and provides a passageway between the axial lumen 136 and the outside of the distal tip 144. The distal passageway 146 facilitates the insertion of the guidewire through the distal end 144 and the axial lumen 136. Preferably, the catheter 130 is constructed of polyurethane or some other suitable biocompatible material.
Referring to
The proximal balloon end 112 and the distal balloon end 114 are preferably fixedly attached to the exterior wall 142 of the catheter 130, by bonding, adhesion, ultrasonic welding or any other attachment means that is suitable to fixedly attach the proximal balloon end 112 and the distal balloon end 114 to the exterior wall 142 of the catheter 130. Preferably, the fixed attachment of the proximal and distal balloon ends 112, 114 to the catheter 130 forms a liquid-tight seal between the balloon 110 and the catheter 130. Preferably, in its deflated state, as shown in
Referring back to
Referring now to
A covering 120, having an outer surface 121 is disposed about and raised very slightly above the outside of the balloon 110 between a proximal covering end 122 and a distal covering end 124. The covering 120 is preferably constructed of plastic or metal, and may be a mesh of flexible woven polyurethane fibers. However, the covering 120 may be constructed out of any other suitable material, as is known to those skilled in the art to define a covering that is flexible enough to expand when the balloon 110 is inflated and contract when the balloon 110 is deflated.
The covering 120 may have a cross-hatched pattern, wherein the cutting edges are at substantially diagonal angles from the longitudinal and circumferential. Also, those skilled in the art will recognize that the covering 120 may have a longitudinal or a lateral pattern as well. The outer surface 121 of the covering 120 is preferably very sharp, thereby facilitating the laceration of lesions, stenoses or other intended materials within the vessel during use. Preferably, when the balloon 110 and the covering 120 are inflated, the fibers of the covering 120 will create an interlocking structure with an abrasive outer surface 121, comprised of sharp individual fibers disposed together in a pattern about the outside of the balloon 110.
The covering 120 may be connected to the balloon 110 at one or more points, or alternatively, the covering 120 may be connected directly to the catheter 130 at one or more points. Alternatively, as shown in
Preferably, as shown in
The axial port 162, which is in fluid communication with the axial lumen 136, facilitates the insertion of a guidewire (see
The exterior port 164 is in fluid communication with the exterior lumen 138, and the luer fitting 166b of the exterior port 164 facilitates the connection of the exterior port 164 to an inflation device such as a syringe (not shown) or other suitable mechanical device (also not shown). Such mechanical devices may be an endoflator or other device known to those skilled in the art.
Referring now to
With reference to
Once the balloon 110 and mesh covering 120 are proximate to the stenoses, plaque or lesions 149 that are to be cut or expanded, the balloon 110 is inflated, by injecting fluid into the exterior lumen 138 of the catheter 130 through the exterior port 164, shown in
Referring now to
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/751,865 filed Dec. 20, 2005.
Number | Date | Country | |
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60751865 | Dec 2005 | US |
Number | Date | Country | |
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Parent | 11642376 | Dec 2006 | US |
Child | 12791346 | US |