Patent Application
20090143728
This invention relates to a balloon catheter generally and, in particular, to a safety feature that is associated with a balloon catheter for preventing harm to a patient in the event the balloon ruptures during a percutaneous medical procedure.
Balloon catheters have been known and used in the art for a number of years. Advances in the art, have considerably reduced the risk of the balloon becoming dislodged from the catheter during a medical procedure. Another risk associated with balloon catheters is the danger of the balloon rupturing inside a patient while inflated. Although the risk of rupture is extremely small, it can be dangerous if the rupture occurs within a vital organ, such as the heart or the like. Pressures of between 60 and 100 psi are often used to inflate catheter balloons and, in the case of a rupture, the escaping inflation fluid as well as any dislodged pieces of balloon membrane can impact sensitive body tissue it comes in contact with. Any residual pieces of membrane that are not recovered can also pose a further danger to the patient.
In the event of a balloon failure taking place during a medical procedure, the catheter generally has to be removed from the patient and a new catheter percutaneously passed into the procedure site. Removal of a catheter with a ruptured balloon attached can sometime prove difficult and potentially dangerous because fragments of the ruptured balloon can be stripped away from the catheter as it is being withdrawn.
It is a primary object of the present invention to improve balloon catheters.
It is a further object of the present invention to protect a patient from harm in the event a balloon that is attached to the distal end of a catheter ruptures during a medical procedure.
A still further object of the present invention is to safely contain the inflation fluid as well as balloon fragments of a balloon catheter in the event the balloon fails during a medical procedure.
Yet another object of the present invention is to prevent the interruption of an in-process medical procedure in the event an inflated balloon of a balloon catheter ruptures during a medical procedure.
These and other objects of the present invention are attained by means of a balloon catheter that has an outer balloon affixed to the distal end of the catheter insertion tube. A second inner balloon is similarly affixed to the insertion tube and is entirely enclosed within the outer balloon. A vacuum pump is connected to the outer balloon through the insertion tube and is arranged to evacuate the atmosphere of the outer balloon. A pump is connected to the inner balloon which is arranged to inflate the inner balloon to a desired pressure. In the event, the inner balloon is ruptured during inflation, the high pressure inflation fluid is released into the outer balloon and is thus contained therein along with any of the inner balloon fragments that might be dislodged because of the rupture. Finally, in certain cases, the medical procedure can proceed without interruption after a rupture by simply inflating the outer balloon to a desired operational level.
For a better understanding of these and other objects of the present invention, reference will be made to the following detailed description of the invention that should be read in association with the accompanying drawings, wherein:
A balloon catheter, generally referenced 10, that embodies the present invention, is illustrated in
The thin walls of the two superimposed balloons, when deflated, provides an extremely compact package upon the distal insertion tube which can pass with relative ease through a blood vessel into a desired treatment zone. The size of the dual balloon package is about the same size as that of a single balloon package and thus does not present any additional problem during insertion and removal of the catheter. The opposite ends of the outer balloons each contain a cuff 30 (
With further reference to
The inner balloon is similarly connected to a syringe 50 by means of a second lumen 51. Again, the syringe is coupled to the proximal end of the lumen and the lumen is passed through the insertion tube to a point below the inner balloon. The distal end of the lumen is passed through the insertion tube into the inner balloon and the connection between the lumen and the insertion tube is closed to form an air tight joint therebetween. A second stop valve 56 is mounted in the proximal end of lumen 51. When the valve is placed in an open position, the syringe is able to deliver sufficient air into the inner balloon to completely inflate the balloon. Closing the valve will prevent air from escaping from the balloon and thus maintain the balloon in an inflated condition.
In operation, before passing the catheter into a blood vessel, the stop valve 56 that controls inflation of the inner balloon is opened as well as the stop valve 40 that controls the evacuation of the outer balloon thus allowing the balloons to be wrapped about the insertion tube into a tight package and the outer balloon is evacuated and valve 40 is closed. Once the balloon package is properly positioned in the treatment site, the inner balloon is inflated. The outer balloon at this time provides little resistance to the expanding inner balloon and simply rides upwardly on the outer balloon until it reaches full inflation whereupon stop valve 56 is closed. If for any reason the inner balloon should fail while fully or partially inflated, the air contained within the inner balloon with be discharged into the slightly larger outer balloon and be fully contained therein. Any fragments of the inner balloon that might breakaway will also be captured within the outer balloon and eventually be safely removed from the patient when the catheter is removed.
The addition of the second balloon to the catheter consumes little additional space and sufficient room is made available within the insertion tube for a third lumen 61 through which a guide wire can pass.
In many cases, failure of a balloon while a medical procedure is in process results in the procedure being terminated and the catheter being removed from the patient and a new procedure having to be initiated. This is not only time consuming but also potentially dangerous and uncomfortable for the patient. The problems associated with a balloon failure during a medical procedure can be avoided by use of this dual balloon arrangement. If such a failure does occur during a procedure, the air escaping from the ruptured inner balloon will partially fill or almost completely fill the outer balloon. If necessary, the syringe servicing the outer balloon can be used to fully inflate the outer balloon through proper operation of the associated stop valve and the procedure carried on to completion.
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.
