Catheters and methods of using catheters
A catheter device and method, in which a first lumen coupled to a balloon, a second lumen coupled to the first lumen, the second lumen having a distal opening to dispense an oxygenated infusate, and a third lumen coupled to the second lumen and coupled to a second balloon. The second balloon restricts the flow of the oxygenated infusate, and the oxygenated infusate provides oxygen to tissue at a distal end of said catheter device.
This application is a continuation of U.S. patent application Ser. No. 10/184,859, filed on Jun. 27, 2002.
FIELD OF THE INVENTIONThe invention, in one embodiment, relates generally to the treatment of coronary disease, and more particularly, in one embodiment, to the delivery of a therapeutic light activated drug.
BACKGROUND OF THE INVENTIONAtherosclerosis, a process in which the walls of the arteries thicken due to the accumulation of plaque in the blood vessels, is the cause of most coronary artery disease that can result in heart attacks, strokes, or inadequate circulation to the extremities. Arterial occlusions caused by plaque accumulation may necessitate major invasive surgery, such as a coronary by-pass procedure. However, less invasive, percutaneous methods may be an alternative in treating atherosclerosis. For example, percutaneous transluminal coronary angioplasty (PTCA) involves advancing a balloon catheter through a body lumen to a target treatment site. In one example, a small incision is made near the femoral artery to insert the catheter, which is then advanced to a plaque area in the coronary artery. The catheter has a deflated balloon near a distal end, and the balloon is positioned across the plaque. Once in position, the balloon is inflated to crack or flatten the plaque, thereby restoring the normal patency of the blood vessel. The balloon is then deflated so that the catheter can be removed, allowing blood flow to resume through the dilated blood vessel.
Another percutaneous catheter treatment method involves drug delivery catheters, which may be used alone or in combination with angioplasty balloons. For example, balloons having micropores may be used to deliver a therapeutic bioactive agent to break-up plaque build-up. One disadvantage of drug delivery catheters that utilize balloons is that the drug, once released from the catheter, requires sufficient time to diffuse into the vessel wall of the treatment site. Otherwise, the drug would be washed downstream by the blood flow. In order to provide sufficient resonance time for diffusion of the drug into the vessel wall, temporary blockage of blood flow upstream from the treatment site may be required. As such, a balloon may be expanded upstream from the treatment site to block blood flow. However, if blood flow is obstructed too long, tissue and organs downstream of the inflated balloon may suffer ischemic damage from lack of oxygenated blood. Ischemia occurs when there is an imbalance between oxygen supply and demand, usually caused by clogged arteries, that leads to insufficient oxygen to tissues such as the heart or brain. The two most common types of ischemia are cardiac and cerebral. Cardiac ischemia includes a continuum of conditions, from silent ischemia to angina to acute myocardial infarction (AMI or “heart attack”). Cerebral ischemia includes transient ischemic attacks (TIAs) and stroke. Consequently, the desired dose to a treatment site may not be achieved in a single procedure because the efficiency of drug diffusion into the vessel wall is not optimized, requiring multiple catheter procedures to adequately treat the target site.
Studies have shown that light activated drugs may be used to treat atherosclerosis. However, ischemia risks may be present with the delivery of light activated drugs. The light activated drug is sensitive to light at a specific intensity or frequency, subsequently targeting cells that have absorbed the drug. However, once released into the blood stream near a target treatment area, the drug requires a certain amount of exposure time to the light for activation, as well as time for the drug to be absorbed into the vessel wall of the treatment site. In order to increase the resonance time to deliver effectively a light activated drug, blood flow needs to be obstructed upstream of the drug delivery area, but this creates the danger of causing ischemia to tissue downstream from the target treatment site.
SUMMARY OF THE DESCRIPTIONA catheter device and method are described, in which, in one embodiment, a first lumen is coupled to a balloon, a second lumen is coupled to the first lumen, and the second lumen has a distal opening to dispense an oxygenated infusate. A third lumen is coupled to the second lumen and is coupled to a second balloon. The second balloon restricts the flow of the oxygenated infusate, and the oxygenated infusate provides oxygen to tissue at a distal end of said catheter device.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which:
In the following description, numerous specific details are set forth such as examples of specific, components, processes, etc. in order to provide a thorough understanding of various embodiment of the present invention. It will be apparent, however, to one skilled in the art that these specific details need not be employed to practice various embodiments of the present invention. In other instances, well known components or methods have not been described in detail in order to avoid unnecessarily obscuring various embodiments of the present invention.
Various embodiments of an apparatus and its method of use to deliver a bioactive infusate or drug within a body vessel are described. In one embodiment, an elongated intraluminal catheter with a drug delivery portion near a distal end is used to deliver an infusate within a body lumen. The drug delivery device has a first inflatable member to obstruct blood flow and a second inflatable member to impede, but not completely block, downstream flow of infusate. Infusion ports are disposed between the first and second inflatable members to release the infusate. Because the second inflatable member impedes downstream flow of infusate, the catheter provides an increased resonance time for the infusate to diffuse into a vessel wall. In one embodiment, the infusate may be an oxygenated cardioplegia solution. The oxygenated cardioplegia solution supplies oxygen to tissue downstream of the first and second inflatable members drug delivery device, thereby prolonging drug delivery time and preventing ischemic effects by the blockage of blood flow by the catheter.
In an alternative embodiment, the drug delivery portion of the catheter may also have a light diffuser capable of activating a light activated drug or bioactive agent released from the infusion ports. In one embodiment, the light diffuser is disposed between the infusion ports and the second inflatable member. As such, the light diffuser may effectively activate the light activated drug before diffusing into a vessel wall. A light activated bioactive agent may be released from the infusion ports and subsequently activated by the light source. The light activated bioactive agent may be mixed with an oxygenated infusate to prolong a treatment delivery time without risking ischemic damage. The drug delivery catheter may be utilized to deliver bioactive agents for the treatment of cardiovascular disease, such as atherosclerosis, or any number of diseases localized or treatable from a body lumen.
In one embodiment, the catheter has multiple lumens to utilize the various parts of the drug delivery portion. The catheter may be an over-the-wire type in which a guidewire lumen extends from the proximal end of the catheter to the distal end, and enables the catheter to advance over the guidewire to a location in the patient's body lumen. A first expandable or inflatable member lumen extends from the proximal end of the catheter to the first inflatable member, such as a balloon. A second inflatable member lumen extends from the proximal end of the catheter to the second expandable or inflatable member, such as a balloon. An infusion lumen extends from the proximal end of the catheter to the infusion ports to release perfusate and/or drug to a location between the two expandable members. A lumen extends from the proximal end of the catheter to the light diffuser containing a means to transfer light or energy from the proximal end of the catheter to the light diffuser. This may be accomplished by a fiber optic member that delivers light to the light diffuser. Alternatively, a light source may be disposed directly behind the light diffuser in which an electrical cable connected to a power source supplies electricity to the light source. Alternatively, the light diffuser may be coupled to a laser. It will be appreciated that the term “light” includes any electromagnetic radiation, whether visible or not.
In one embodiment of a method of using the drug delivery catheter, the catheter is advanced to a desired location in the patient's body lumen (i.e., target location) by first inserting a guidewire through the body lumen to the treatment site. The catheter may also contain its own guide wire component to provide the catheter with the ability to steer its way to the target location. As an alternative to an over-the-wire catheter, a rapid exchange catheter delivery system may be utilized. As such, the catheter may be any of the catheter types used in the art, including but not limited to “rapid exchange” (RX) catheters, “over-the-wire” (OTW) catheters, or a “tip RX” catheters. The catheter is positioned so that the target site (e.g., the site where an infusate is to be eluted from the catheter) is between the first and second inflatable members. Once the catheter is advanced to the target treatment site, the first inflatable member is expanded to obstruct blood flow proximal to the treatment site. Next, an infusate is released from the infusion ports. In one embodiment, the infusate may be a bioactive agent. Alternatively, the infusate may be a light activated bioactive agent. The bioactive agent may also be mixed with a solution of oxygenated cardioplegia fluid.
The second inflatable member, disposed downstream from the infusion ports, is expanded to impede the distal run off of the bioactive agent, thereby providing greater resonance time for diffusion into the vessel wall of the treatment site. Because the second inflatable member allows for some downstream run-off of the bioactive agent, the oxygenated cardioplegia supplies oxygen to downstream tissue that was initially denied by the expansion of the first inflatable member. Alternatively, a perfusion lumen having an opening downstream from the second inflatable member may provide oxygenated blood (from an opening upstream from the first inflatable member) to tissue which is downstream from the first inflatable member (and preferably downstream from the second inflatable member). As such, the catheter may be placed in the body vessel near the treatment area for greater time periods compared to a drug delivery catheter without oxygenated cardioplegia. Alternatively, if a light activated bioactive agent is released, a light source may be activated to diffuse a light from a light diffuser, also disposed between the first and second inflatable members, and projected toward the vessel wall to activate the drug. In an alternative embodiment, a light source may be incorporated into the distal shaft where it may directly deliver light to the light diffuser.
Turning now to
The embodiment illustrated in
The cross-sectional view
Discussed in greater detail below with respect to the method of using drug delivery catheter 100, first inflatable member 240 and second inflatable member 250 are shaped differently to control the flow of blood or perfusate around the distal end of catheter 100. For example, first inflatable member 240 is shaped, when fully expanded, such that it makes continuous contact with the vessel wall near a target area to block blood flow upstream from infusion ports 260. Second inflatable member 250 is shaped, when fully expanded, such that it restricts downstream flow of fluid. Unlike first inflatable member 250, second inflatable member 260 does not completely block fluid flow.
Returning now
Distal portion 200 of the drug delivery catheter also has light diffuser 270 to disperse light between first inflatable member 240 and second inflatable member 250. In one embodiment, light diffuser 270 may be a lens or comparable light transparent material. In use, light is released from light diffuser 270 at a particular frequency/wavelength and intensity to activate light activated bioactive agent released from infusion ports 260. In one embodiment, light diffuser 270 is disposed distal to infusion ports 260 because the released light activated bioactive agent travels downstream toward second inflatable member 250. Light diffuser may be configured such that the activating light is focused in the direction of second inflatable member 250.
In an alternative embodiment, light diffuser 270 may be coupled to a light source disposed near a proximal end of drug delivery catheter. Light travels through a lumen (e.g., lumen 118 illustrated in
The phenomenon of photosensitization is typically dependent on frequency/wavelength and the intensity of the light. There are ranges for both frequency/wavelength and the intensity of the light, which span from no light activation of a drug to over-activation of a drug. Examples of light activated drugs include, but not limited to: Motexatin Lutetium produced by Pharmacyclics, which is activated by light at a frequency of 730 nanometers and an intensity of 180 Joules/cm2; Tin Ethyl Etiopurpurin produced by Miravent, which is activated by light at a frequency of 662 nanometers and an intensity of 90 Joules/cm2; 5-Amino-Levulinic Acid, which is activated by light at a frequency of 630 nanometers and an intensity of 50 Joules/cm2; and Protoporphyrin IX, which is activated by light at a frequency of 630 nanometers and an intensity of 50 Joules/cm2. The values stated for frequency and intensity are examples for the peak activation of each drug within a given range.
The perspective view of
Distal portion 335 of catheter 300 has first inflatable member 340 and second inflatable member 350 coupled together by segment 365. Segment 365 has infusion ports 360 and light diffuser 370. As illustrated in
Next, as illustrated in
As discussed above, second inflatable member 350, when fully expanded, does not form a seal around arterial lumen 305 when it is desired to allow a downstream flow past the second inflatable member 350. The shape of second inflatable member 350 is such that fluid passes around second inflatable member 350. In one embodiment, second inflatable member 350 may have a series of perfusion paths around the outer surface. In another embodiment, second inflatable member 350 may be a helical balloon in which a perfusion path spirals around the outer surface (e.g.,
In an alternative method, first inflatable member 340 expands to block blood flow upstream from the plaque 310. Next, second inflatable member 350 expands to limit down stream flow. Third, infusion ports 360 release a light activated drug that spreads towards plaque 310, and downstream in the direction of second inflatable member 350. Next light diffuser 370 releases light to activate light drug 365 released from infusion ports 360.
Second inflatable member 350 allows light activated drug 365 to remain near plaque 310 of the target treatment area to increase the resonance time that drug 365 can diffuse into the vessel wall 320 of plaque 310. In doing so, the efficiency of the drug may be increased. Additionally, as discussed above, light activated drug 365 may be part of an oxygenated cardioplegia solution. As such, because second inflatable member 350 does not completely block downstream flow, the solution of oxygenated cardioplegia released from infusion ports 360 may supply oxygen to downstream tissue, thereby preventing ischemia. Alternatively, catheter 300 may be used to release a non-light activated drug from infusion ports 360. Second inflatable member 350 would still be effective in increasing the resonance time of any type of drug released, and, if part of an oxygenated cardioplegia solution, would provide oxygen to tissue downstream from catheter 300.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
Claims
1-5. (canceled)
6. A method of treating a body vessel, said method comprising:
- inserting a catheter device comprising at least one lumen near a treatment site within said body vessel;
- expanding a first inflatable member of said catheter device disposed upstream from said treatment site to obstruct blood flow;
- infusing an oxygenated infusate through said catheter device and into said body vessel near said treatment site;
- expanding a second inflatable member of said catheter device disposed downstream from said treatment site to reduce downstream flow rate where said oxygenated infusate can flow past said second inflatable member and perfuse portions of said body vessel downstream from said treatment site.
7. The method of claim 6, wherein said oxygenated infusate further comprises a light activated bioagent.
8. The method of claim 6, wherein said second inflatable member further comprises a balloon with variable diameter.
9. The method of claim 6, wherein said catheter device further comprises a light diffuser disposed between said first inflatable member and said second inflatable member.
10. The method of claim 9, wherein expanding said second inflatable member increases a resonance time for said light activated bioagent to infuse into said treatment site.
11. A method of treating a body vessel, said method comprising:
- inserting a catheter device including two inflatable members, a light diffuser and an infusion port into said body vessel near a treatment site;
- expanding a first inflatable member proximal to said treatment site to occlude flow to said treatment site;
- expanding a second inflatable member distal to said treatment site to reduce flow from said treatment site to portions of the vessel downstream from said second inflatable member;
- infusing an oxygenated and light activated infusate through said infusion port about said treatment site; and
- shining a light, capable of activating said oxygenated and light activated infusate, from said light diffuser about said treatment site.
12. The method of claim 111 wherein said two inflatable members are of different constructions.
13. The method of claim 12 wherein said two inflatable members are of different shapes.
14. The method of claim 11 wherein said light diffuser and said infusion ports are disposed between said two inflatable members.
15. The method of claim 11 wherein said oxygenated and light activated infusate includes a drug to treat at least one of atherosclerosis, vessel occlusion and vessel inflammation.
16. The method of claim 15 wherein light at a particular frequency (or wavelength) and intensity is released from said light diffuser to activate light activated bioactive agent released from the infusion port.
17. The method of claim 15 wherein a light source for said light diffuser is at least one of a fiber optic assembly and a LED.
18. The method of claim 11 wherein the said second inflatable member is a balloon that has a variable diameter that forms perfusion paths along the balloon's outer surface.
19. A method of treating a body vessel, said method comprising:
- inserting a catheter device including two inflatable members and infusion ports into said body vessel near a treatment site;
- expanding a first inflatable member disposed near a proximal end of the catheter device to occlude flow;
- expanding a second inflatable member disposed near a distal end of the catheter device to partially impede a downstream flow; and
- infusing an oxygenated and light activated infusate through said infusion ports and into said body vessel.
20. The method of claim 19 wherein the two inflatable members are of different constructions.
21. The method of claim 20 wherein the oxygenated and light activated further comprises a drug to treat at least one of atherosclerosis, vessel occlusion and vessel inflammation.
22. The method of claim 21 wherein said infusion ports and an additional light diffuser are both located between the two inflatable members.
23. The method of claim 22 wherein the light diffuser is capable of activating said light activated bioactive agent by shining a light from said light diffuser to said body vessel.
24. The method of claim 23 wherein light at a particular frequency (or wavelength) and intensity is released from said light diffuser to activate said infusate released from the infusion port.
25. The method of claim 24 wherein a light source for said light diffuser is at least one of a fiber optic assembly and a LED.
26. A medical device, comprising:
- a catheter with at least a proximal inflatable member and a distal inflatable member;
- the proximal inflating member, after inflated, to occlude flow from upstream;
- the distal inflating member, after inflated, to allow partial flow downstream; and
- an oxygenated infusate infusion port displaced on the catheter device.
27. The medical device of claim 26 wherein the two inflatable members are of different constructions to control flow of blood or infusate.
28. The medical device of claim 27 wherein the distal inflatable member is a helical balloon.
29. The medical device of claim 26 wherein a light activated bioagent is mixed with the oxygenated infusate.
30. The medical device of claim 29 wherein a light diffuser is also displaced on the catheter device and a light source for the light diffuser is at least one of a fiber optic assembly and a LED.
31. The medical device of claim 30 wherein light at a particular frequency (or wavelength) and intensity is released from said light diffuser to activate said light activated bioagent.
32. The medical device of claim 30 wherein both the light diffuser and the oxygenated infusate infusion port are both displaced between the two inflating members.
Type: Application
Filed: Sep 27, 2006
Publication Date: Apr 19, 2007
Inventor: Gregory Hyde (Menlo Park, CA)
Application Number: 11/528,985
International Classification: A61M 31/00 (20060101); A61N 1/30 (20060101);