DUAL DILATATION BALLOON AND INFUSION BALLOON CATHETER

Abstract: The present invention relates to a catheter which is capable of performing both an angioplasty procedure using a dilatation balloon (40) and application of therapeutic drugs using an infusion balloon (50). The catheter according to the present invention is advantageous because it eliminates the need for removal and reinsertion of separate catheters or repositioning of the same catheter to perform the dilatation and infusion procedures. The present invention also relates to a dual dilatation balloon and infusion balloon catheter, wherein the infusion balloon (50) is capable of infusing insoluble therapeutic agents to the treatment site. This is advantageous because the insoluble agents exhibit improved tissue residence profiles and more beneficial treatment characteristics.

Description: DUAL DILATATION BALLOON AND INFUSION BALLOON CATHETER This is a continuation-in-part application of United States application, serial number 07/897,635 filed June 12, 19-92. Background The present invention relates to a catheter which can be sequentially used to perform angioplasty and then the administration of therapeutic agents. In particular, the present invention relates to a catheter having both dilatation and infusion balloons, wherein the infusion balloon has pores optimally sized to allow infusion of insoluble therapeutic agents. Percutaneous transluminal angioplasty (PTA) procedures typically are performed using a guiding catheter which may be percutaneously introduced into the cardiovascular system of the patient through the brachial or femoral arteries and" advanced therein until the tip thereof is properly positioned in the ostium of the afflicted artery. A guidewire and a dilatation balloon catheter are then introduced through the guiding catheter, the guidewire being disposed within an inner lumen of the balloon catheter. The guidewire and balloon are advanced until the dilatation balloon is properly located within the area of lesion to be treated. Once positioned, the dilatation balloon is inflated to a predetermined size using a radiopaque liquid, such as contrast medium, in order to radially compress the atherosclerotic plaque of the lesion against the inside of the artery wall and thereby dilate the lumen of the artery. The dilatation balloon is then deflated and the balloon catheter removed so that blood flow may be resumed through the dilated artery. Another means of treating stenosed arteries is through the administration of drugs such as anticoagulants, anti- proliferatives or gene transfection reagents. These drugs are commonly delivered to the stenosed artery through an infusion catheter which includes small holes formed through the catheter wall or through the wall of a balloon formed on the catheter, so that the drug may be allowed to contact with the area of treatment over a prolonged time period. It may also be desirable to infuse therapeutic agents which have been encapsulated into insoluble particles, such as, microspheres, liposomes, viruses, viral like particles, or other insoluble or colloidal formulations which provide for more controlled release of the therapeutic agent. Such insoluble particles exhibit improved tissue residence profiles, and therefore, may provide more favorable treatment results than primarily soluble agents. Unfortunately, when balloon angioplasty is used to restore patency of the artery, thrombolytic or proliferative events may operate to reocclude the artery following the balloon dilatation. Also, the use of drug therapy alone is not effective for treatment of all stenoses, and use of an dilatation balloon may be necessary. It is therefore, desirable to be able to provide for both balloon angioplasty and drug administration through the same catheter. Further, it is desirable to be able to infuse insoluble therapeutic agents to the treatment area through the same catheter which has been used for dilatation. Objects Of The Invention It is one object of the present invention to provide a dilatation catheter which can perform both balloon dilatation and therapeutic drug delivery. It is another object of the present invention to provide a dual dilatation balloon and infusion balloon catheter, wherein the infusion balloon is capable of infusing insoluble therapeutic agents to the treatment site. Summary Of The Invention The objects of the present invention are accomplished by providing a catheter having a two concentrically formed balloons, the inner most balloon capable of performing dilatation, and the outer balloon capable of delivering therapeutic drugs. The outer balloon comprises an infusion balloon having infusion pores optimally sized to allow for infusion of soluble therapeutic agents to the treatment site. Brief Description Of The Drawings Fig. 1 is a plan view of a catheter according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view of a catheter according to the first embodiment of the present invention, taken along line A-A of Fig. 1. Fig. 3 is a plan view of a catheter according to a second embodiment of the present invention. Fig. 4 is a cross-sectional view of a catheter according to the present invention, taken along line B-B of Fig. 3. Fig. 5 is a cross-sectional view of a catheter according to the present invention, taken along line C-C of Fig. 3. Detailed Description Of The Invention Fig. 1 is a plan view of a catheter according to a first embodiment of the present invention. The catheter generally designated by reference numeral 10, includes a multi-lumen shaft 20, one lumen of which serves as a guidewire lumen, a second lumen of which serves as a dilatation balloon inflation lumen, and a third lumen of which serves as a therapeutic drug infusion lumen. As best shown in Fig. 2, the various lumens of the shaft 20, according to this embodiment are formed in a concentric configuration ^ . In particular, a guidewire lumen 35, extends the entire length of the catheter 10, ending at the distal end 30. The guidewire lumen 35, is surrounded by a dilatation balloon inflation lumen 45, which extends form a proximal end of the catheter 10, to a dilatation balloon 40, formed near the distal end 30. The dilatation balloon inflation lumen 45, is surrounded by an infusion lumen 55, which extends from a proximal end of the catheter 10, to an infusion balloon 50, formed near the distal end 30. The infusion balloon 50, includes infusion pores 58, which allow for the infusion of therapeutic agents to a treatment site. The infusion pores 58, normally have a diameter in the range of 15 to 75 microns, preferably about 25 to 50 microns. Infusion pores 58, having such a diameter allow for infusion of soluble therapeutic agents. Infusion of large numbers or a high concentration of insoluble particles having a particle size greater than 1 microns in diameter may cause problems of clogging or partial blocking of the infusion pores 58, unless special measures are taken. The pore size of infusion pores 58, may be increased so as to allow the administration of insoluble particles. Pore sizes up to 250 microns, preferable about 100 microns in diameter may be successfully employed in the infusion of large numbers or a high concentration of insoluble therapeutic agents having a particle size up to 25 microns in diameter. However, when relatively large pore sizes are utilized, optimal hydrostatic pressure may be compromised which could result in inadequate perfusion. This problem may be overcome and optimal conditions for hydrostatic pressure can be controlled by regulating the number of infusion pores 58. Fig. 3 is a plan view of a catheter according to a second embodiment of the present invention. The catheter, generally designated by reference numeral 100, differs from the catheter shown in Fig. 1 only by the provision of a main shaft 120, having lumens in a side-by-side configuration, attached to a balloon shaft 125, having lumens in a concentric configuration. The main shaft 120, and balloon shaft 125, are attached at joint portion 160. As best shown in Fig. 4, the main shaft 120, includes a guidewire lumen 135, a balloon dilatation inflation lumen 145, and an infusion lumen 155, each of which extend the entire length of the main shaft 120, from a proximal end of catheter 100, to the joint portion 160. The lumens 135, 145 and 155 are formed in a side-by-side configuration. As best shown in Fig. 5, the balloon shaft 125, includes concentrically formed lumens. A guidewire lumen 135' extends the entire length of the balloon shaft 125, from the joint portion 160, to the distal end 130, of catheter 100. The guidewire lumen 135', is surrounded by a dilatation balloon inflation lumen 145', which extends from the joint portion 160, to a dilatation balloon 140, formed near the distal end 130. The dilatation balloon inflation lumen 145', is surrounded by in infusion lumen 155' which extends from the joint portion 160, to an infusion balloon 150, formed near the distal end 130. The infusion balloon 150, includes infusion pores 158, which allow for the infusion of therapeutic agents to a treatment site. The infusion pores 158, again have a diameter in the range of 15 to 75 microns, preferably about 25 to 50 microns, to allow for infusion of soluble therapeutic agents. As noted above, the diameter and number of infusion pores may be adjusted to allow for infusion of insoluble particles. The main shaft 120, and balloon shaft 125, may be joined by any suitable method such that the corresponding lumens of the two shafts are joined. In particular, guidewire lumens 135, and 135' are joined; dilatation balloon inflation lumens 145 and 145' are joined; and infusion lumens 155 and 155' are joined. In each instance, the joining should provide a continuous lumen from the proximal end of the catheter 100, to the distal end 130, dilatation balloon 140, or infusion lumen 150, as appropriate. The catheter according to the present invention is very advantageous in helping to prevent reocclusion or stenosis of arteries following a balloon angioplasty procedure. In particular, it is possible to perform an angioplasty procedure using the dilatation balloon of the catheter according to the present invention, followed by the infusion of therapeutic drugs through the infusion balloon, without requiring the removal and reinsertion of separate catheters. This is extremely advantageous in saving time and energy in assuring exact placement and in avoiding excessive damage to the arterial structure of a patient. This construction is also advantageous in reducing "dead volumn" and conserving expensive drugs by reducing waste per dose. In addition, the catheter according to the present invention is very advantageous because it allows both angioplasty and drug infusion to be carried out at their different optimal inflation pressures. Also, the catheter according to the present invention is very advantageous in allowing for the infusion of insoluble therapeutic agents. The relatively large infusion pores provided through the infusion balloon of the catheter according to the present invention allow such insoluble therapeutic agents to be delivered directly to the treatment site. This is advantageous because insoluble therapeutic agents exhibit improved tissue residence profiles and thus more favorable treatment characteristics. Use of the catheter according to the present invention can greatly reduce the risk of restenosis of a dilated artery by providing treatment thereof in a more expeditious manner than possible with prior art catheters. Further, use of the catheter according to the present invention can enable delivery of insoluble therapeutic agents directly to the treatment site, such insoluble agents providing more beneficial treatment results and characteristics. The foregoing has been a description of certain preferred embodiments of the present invention, but is not intended to limit the invention in any way. Rather, many modifications, variations and changes in details may be made within the scope of the present invention.

Claims: What is claimed is: 1. A catheter capable of performing both dilatation and infusion of therapeutic drugs, said catheter comprising; a guidewire lumen; a dilatation balloon inflation lumen coaxially surrounding said guidewire lumen at least along a distal end portion of said catheter, said inflation lumen including a dilatation balloon formed along a portion of its length; and an infusion lumen coaxially surrounding said inflation lumen at least along said distal end portion of said catheter, said infusion lumen including an infusion balloon formed along a portion of its length. wherein said infusion balloon includes infusion pores having a size capable of infusing insoluble diagnostic agents. 2. A catheter according to claim 1, wherein said dilatation balloon inflation lumen surrounds said guidewire lumen, and said infusion lumen surrounds said dilatation balloon inflation lumen along substantially the entire length of said catheter. 3. A catheter according to claim 1, further comprising: a main shaft in which said guidewire lumen, said dilatation balloon inflation lumen, and said infusion lumen, are formed in a side-by-side configuration; and a balloon shaft in which said guidewire lumen is surrounded by said dilatation balloon inflation lumen, and said dilatation balloon inflation lumen is surrounded by said infusion lumen; • wherein said main shaft and balloon shaft are joined at a joining portion, such that said guidewire lumen, said dilatation balloon inflation lumen, and said infusion lumen extend substantially the entire length of said catheter. 4. A catheter according to claim 1, wherein said infusion pores have a diameter which allow for infusion of soluble diagnostic agents. 5. A catheter according to claim 4, wherein said infusion pores have a diameter in the range of 15 to 75 microns. 6. A catheter according to claim 5, wherein said infusion pores have a diameter of about 25 to 50 microns. 7. A catheter according to claim 1, wherein said infusion pores have a diameter which allow for infusion of insoluble diagnostic agents having particle sizes up to about 25 microns in diameter. 8. A catheter according to claim 7, wherein said infusion pores have a diameter in the range of 35 to 250 microns. 9. A catheter according to claim 8, wherein said infusion pores have a diameter of about 100 microns.

Inventors: BURLEIGH B DANIEL, LYLE LEON R, BURLEIGH, B., DANIEL, LYLE, LEON, R.
Applicants: MALLINCKRODT MEDICAL INC, MALLINCKRODT MEDICAL, INC.
Application year: 1993
Main classification: A61M29
IPC codes: A61M16, A61M25, A61M29