Method of detecting vulnerable atherosclerotic plaque

• US 6,475,159 B1
• Filed: 03/15/1999
• Issued: 11/05/2002
• Est. Priority Date: 09/20/1995
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Bearman, Gregory H., Willerson, James T., Casscells, S. Ward, Eastwood, Michael L., Krabach, Timothy N.
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): Szmal, Brian
• Application Number:
  US09/268,609
• Time in Patent Office: 1,331 Days
• Field of Search: 600/549, 600/474, 600/473, 128/898, 128/665, 530/388.22, 604/114, 604/95, 606/12, 606/7, 606/15, 606/17, 374/131
• US Class Current: 600/549
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/015 By temperature mapping of body part
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/413 Monitoring transplanted tissue or organ, e.g. for possible rejection reactions after a transplant
• CPC Class Codes: A61B 5/6853 with a balloon

Abstract

An infrared, heat-sensing catheter particularly useful for identifying potentially fatal arterial plaques in patients with disease of the coronary or other arteries and its use are detailed. In one embodiment, an infrared fiberoptic system (with or without ultrasound) is employed at the tip of the catheter to locate inflamed, heat-producing, atherosclerotic plaque, which is at greater risk for rupture, fissure, or ulceration, and consequent thrombosis and occlusion of the artery. In another embodiment, a catheter with an infrared detector (with or without ultrasound) employed at its tip will likewise locate inflamed heat-producing atherosclerotic plaque. The devices and methods of the invention may be used to detect abscesses, infection, and cancerous regions by the heat such regions differentially display over the ambient temperature of immediately adjacent tissues. The methods and devices of the invention may also be used to detect regions of cooler than ambient tissue in a vessel or organ which indicate cell death, thrombosis, cell death, hemorrhage, calcium or cholesterol accumulations, or foreign materials.

Claims

1. A method of surgically treating a patient with a plurality of plaque loci within a vessel of said patient, comprising:

determining which one or more of said plurality of plaque loci has a temperature elevated above that of the average vessel wall temperature; and

,

removing or reducing plaque loci found to have said elevated temperature.

2. A method of identifying a vulnerable atherosclerotic plaque in a living vessel comprising the steps of:

detecting a region along the luminal wall having a temperature that is higher than that of an adjacent region; and

locating the vulnerable plaque based upon the higher temperature of the detected region.

3. The method of claim 2 wherein said detecting comprises measuring the temperature of a plurality of sites along the lumen wall of said vessel, determining average vessel wall temperature and determining a temperature elevation in at least one said site of up to 5°

C. above said average vessel wall temperature.

4. The method of claim 2 wherein said detecting comprises employing an intravenous or non-invasive thermography device.

5. A method of treating a patient suffering from atherosclerosis comprising identifying at least one vulnerable plaque according to the method of claim 2 and delivering to said plaque a monocyte inhibitory agent.

6. The method of claim 5 wherein said delivering comprises delivering an inhibitory agent chosen from the group consisting of monocyte recruitment preventatives, monocyte attachment preventatives, monocyte activation preventatives, and monocyte DNA synthesis preventatives.

7. A method of identifying a vulnerable atherosclerotic plaque in a living endarterectomy specimen comprising the steps of:

detecting a region of said specimen having a temperature that is higher than that of an adjacent region; and

locating the vulnerable palque based upon the higher temeperature of the detected region.

8. The method of claim 7 wherein said detecting comprises using a thermistor or infrared thermometry device.

9. A method of identifying a vulnerable atherosclerotic plaque in a living vessel comprising detecting a region along the luminal wall having a temperature that is higher than that of an adjacent region by measuring the temperature of a plurality of sites along the lumen wall of said vessel, determining average vessel wall temperature and determining a temperature elevation in at least one said site of up to 5°

C. above said average vessel wall temperature.