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METHOD FOR TREATMENT OF ANEURYSMS
CROSS-REFERENCE TO RELATED
 This application is a continuation-in-part of pending U.S. patent application Ser. No. 10/839,766, filed May 5, 2004, entitled METHOD FOR TREATMENT OF ANEURYSMS, which application is a continuation-in-part of U.S. patent application Ser. No. 09/964,264, filed Sep. 26, 2001, entitled METHOD AND DEVICE FOR TREATMENT OF ANEURYSMS, now allowed.
STATEMENT REGARDING FEDERALLY
SPONSORED RESEARCH OR DEVELOPMENT
FIELD OF THE INVENTION
 The present invention relates to a method and device for treating vascular defects such as aneurysms, dissections, arterio-venous malformation and vulnerable plaque, and in particular, to a method involving the use of a catheter and thermo-cryogenic, electromagnetic, and ultrasonic energy sources concomitantly with an additional treatment to treat tissue.
BACKGROUND OF THE INVENTION
 Aneurysms are distensions formed by the localized dilation of the wall of an artery, a vein, or the heart. An aneurysm balloons due to the pressure of blood flowing through an area weakened due to disease, injury, or congenital defect. A "true" or common aneurysm results from the formation of a sac by the arterial wall, or tunica media, which remains unbroken, and may be associated with atherosclerosis. In a "false" or dissecting aneurysm, usually caused by trauma, a fissure in the wall of a blood vessel allows blood to escape into surrounding tissues and form a clot.
 Doctors typically monitor the inflammation and progression of aneurysms using devices known in the art such as MRI and CT scanners and by observation of known patient symptoms. Typically, however, early stage aneurysms do not warrant dangerous surgical procedures, even if minimally invasive, due to the associated morbidity risk. Accordingly, the doctors choose a "wait and see" approach. Because surgery for aneurysms is risky, the surgeon may wait for the aneurysm to expand to a certain size before operating, when the risk of complications exceeds the risk of surgery. Accordingly, it would be desirable to treat aneurysms upon early detection rather than wait until they progress to a stage that requires dangerous, expensive surgery, or become life-threatening conditions.
 In addition to aneurysms, certain other vascular defects are of interest, such as a dissection. Vascular dissections are similar to aneurysms in that the vessel wall integrity is compromised. However a dissection consists of a laceration of a portion of the vessel wall. Both dissections and lacerations are associated risks stemming from arterial disease.
 Therefore, it would be desirable to have a device, coupled with a minimally invasive method, to retard, arrest and even reverse, the processes that lead to vascular defects
such as dissections or aneurysm formation, and arteriovenous malformation or vulnerable plaque.
SUMMARY OF THE INVENTION
 A method for treating a vascular defect is disclosed. A catheter having an energy-transfer element is positioned and disposed proximate a target tissue region including the vascular defect. Energy is transferred between the energy-transfer element and the target tissue region. The energy may be emitted as a treatment energy from the energy-transfer element, and further directed to be in part absorbed by the target tissue region. The treatment energy may be any of the following group: visible light energy, laser light energy, ultrasonic periodic mechanical vibrational, or ultrasound, energy, and microwave or radiofrequency electromagnetic energy. Alternatively, the energy-transfer element is a heat-absorbing device, and heat is transferred from the target tissue region to the heat-absorbing device. The heat transfer element can include an expansion chamber, wherein a coolant is injected into the expansion chamber. In addition, the treatment method may include providing energy transfer paired with an additional treatment method, including drug delivery, the use of an implanted medical device, a biological filler material, or an endovascular graft.
 In another embodiment, a method is provided for thickening, strengthening, or increasing the density of a blood vessel wall. A catheter is provided having an energytransfer element. The catheter is positioned such that the energy-transfer element is disposed proximate the blood vessel wall. A flow of treatment energy is transferred between the energy-transfer element and the blood vessel wall.
 In yet another embodiment, a method is provided for enhancing collagen production in blood vessels proximate a vascular defect. Collagen inducing growth factors are injected into a target tissue region proximate the vascular defect. A device having a discrete light energy-emitting element is provided. The element is disposed proximate to the target tissue region. The energy-emitting element is directed to emit light energy and to irradiate the target tissue region with said light energy. The collagen inducing growth factors are activated with the light energy.
 In still yet another embodiment, a method is provided for cryotreating vulnerable plaque. The method provides for the treatment of plaque formed on an interior lumenal surface of a body or blood lumen. A cooling device is positioned at the interior lumenal surface at a point proximate to a plaque formation. The lumenal surface is cooled at the point proximate to the plaque formation to inhibit the progression of plaque formation in which the lumenal surface is cooled to a temperature of less than about zero degrees Celsius.
BRIEF DESCRIPTION OF THE DRAWINGS
 A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
 FIG. 1 is a cross-sectional view of a balloon catheter device disposed inside of a blood vessel proximate an aneurysm;
 FIG. 2 is a cross-sectional view of a catheter with a cooling segment positioned proximate the arterial wall in an aneurysm;
 FIG. 3 is a perspective view of a balloon-cuff catheter device for contact with an aneurysm outside the arterial wall;
 FIG. 4 is a view of a catheter device using photodynamic energy disposed inside of a blood vessel proximate an aneurysm;
 FIG. 5 is a view of a catheter device using laser energy disposed inside of a blood vessel proximate an aneurysm;
 FIG. 6 is a view of a catheter device using sound energy disposed inside of a blood vessel proximate an aneurysm;
 FIG. 7 is a view of a catheter device using microwave energy disposed inside of a blood vessel proximate an aneurysm;
 FIG. 8 is a view of a catheter device using radio frequency energy disposed inside of a blood vessel proximate an aneurysm;
 FIG. 9 is a view of a catheter device disposed inside of a blood vessel proximate a dissection;
 FIG. 10 is a view of a catheter device having an energy-transfer element and delivering a compound inside of a blood vessel proximate an aneurysm;
 FIG. 11 is a view of a catheter device having an energy-transfer element and delivering a mechanical intravascular device inside of a blood vessel proximate an aneurysm;
 FIG. 12 is a view of a catheter device having an energy-transfer element and delivering an endovascular graft inside of a blood vessel proximate an aneurysm; and
 FIG. 13 is a view of a balloon catheter device inflated within a blood vessel to contact an area of vulnerable plaque.
DETAILED DESCRIPTION OF THE
 As used herein, a "vascular defect" shall mean an aneurysm, a dissection, or vulnerable plaque as further described and set forth herein. An aneurysm is typically characterized by a localized dilatation in a blood vessel, while a dissection occurs when a defect in the lining of a blood vessel allows an opening or tear to develop in the vessel wall.
 Vascular or vulnerable plaque is typically caused by coronary artery disease, and involves the formation of plaque, a combination of cholesterol and cellular waste products that form on the interior wall of an artery. Eventually, the plaque deposit can develop a thin covering called a fibrous cap. With plaque progression, the vessel wall can experience inflammation, leading to the erosion of the fibrous cap. The erosion may cause the plaque cap to crack, allowing the underlying plaque elements to come in contact with the blood stream. Exposure of these elements to the blood stream can cause clot formation, leading to coronary artery occlusion, myocardial ischemia and infarction. This
particular type of lipid-rich plaque, having active inflammation and the potential to erode the overlying fibrous cap, which in turn can lead to thrombosis and myocardial infarction is called unstable or vulnerable plaque.
 Catheter based devices enable access to the weakened arterial wall around an aneurysm, a dissection or venerable plaque, are minimally invasive, and may be employed for a variety of diagnostic and therapeutic functions. Localized application of cold temperatures to the blood vessel wall may serve to strengthen and thicken the distended and dilated tissue of an aneurysm, and make such tissue layers increasingly dense, as well as inhibit the progression of plaque formation. Accordingly, by applying such cold, or cryotreatment, to the aneurysm, dissection or vulnerable plaque site, the aneurysm, dissection or vulnerable plaque may be effectively treated without major surgery.
 FIG. 1 illustrates a blood vessel and a device during a procedure for cryotreatment of an aneurysm. In FIG. 1, a balloon catheter, labelled generally as 10, is disposed inside of a blood vessel 11 proximate to an aneurysm 12. The balloon catheter 10 includes a flexible, expandable membrane or balloon 13 coupled to a catheter tube 14, wherein the catheter 10 is guided to the desired treatment site via a guidewire 15. In this procedure, the balloon catheter 10 is percutaneously inserted into the vasculature and advanced to the locus of the aneurysm 12. The specific size and shape of the balloon 13 and catheter tube 14 may be determined a priori in order to best fit the targeted artery or blood vessel where an aneurysm has formed. The balloon 13 is thereby inflated to appose the inner walls of the blood vessel proximate the aneurysm 12, so as to enable cryotreatment of the aneurysm 12 tissue.
 However, contrary to conventional angioplasty procedures, the dilatation and apposition of the balloon 13 versus the inner walls of the aneurysm is not meant to dilate the blood vessel walls. Rather, the device employed in this procedure uses a balloon-tipped catheter configured to receive the flow of a coolant, or cryogenic fluid, therein. High-pressure coolant fluid is connected to the proximal section of the catheter tube 14, which contains several tubes and lumens (not shown) adapted to contain the flow of coolant therein. The coolant used may be any stable working fluid capable of being compressed to high pressure, pumped though small diameter devices, and expanded to produce endothermic cooling at a desired location. Examples of such coolants are nitrogen, nitrous oxide, or any conventionally used refrigerant. The coolant may be in liquid, gaseous, or mixed phase form. The flow system inside of the catheter may be either closed loop, wherein the injected coolant is returned to the source for recycling and re-entry into the device, or open loop, wherein the coolant is pumped through the device only once, whereupon it exits outside the body and is discarded.
 The coolant flows through the catheter tube 14 and is injected, generally along coolant flow lines F, into the balloon 13 at the distal tip of the catheter 10, whereupon the balloon 13 expands as the coolant is both vaporized and expanded inside the balloon. The combined evaporation and expansion of the coolant creates endothermic cooling in the near field of the balloon 13. The process is endothermic in that heat, or thermal energy, is absorbed by the balloon 13,