US6451044B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for heating inflammed tissue
Assignee: The University of Texas System
•
Filing: 1999-12-28
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Granted: 2002-09-17
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Expires: 2019-12-28
Abstract
Abstract The present invention relates to methods for treating inflammation in body tissues. More specifically, certain disclosed methods relate to selectively inducing apoptosis in inflammatory immune cells by heating cells for a sufficient time and at a sufficient temperature to induce programmed cell death. The disclosed stents can be placed in contact with the inflammatory cells and heated under controlled conditions. The disclosed apparatus and methods are particularly suitable for treating athersclerotic plaques.
Inventors
- 👤 Morteza Naghavi
- 👤 Bujin Guo
- 👤 Birendra Lal
- 👤 S. Ward Casscells, III
- 👤 James T. Willerson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:40
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/82; A61F2/86; A61N; A61N5/00; A61N5/06; A61N5/0601; A61N7/00; A61N7/02; A61B; A61B17/00; A61B17/22; A61B2017/22001; A61F7/00; A61F2007/0088
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
22 words
An ultrasonically heatable stent comprising at least one ultrasound-absorptive material characterized by an acoustic impedance greater than that of living soft tissue.
Claim 2
Dependent Claim
22 words
An ultrasonically heatable stent comprising at least one ultrasound-absorptive material characterized by an acoustic impedance greater than that of living soft tissue.
Claim 3
Dependent Claim
47 words
The stent of claim 1 further comprising: a stent framework configured to maintain patency of a human vessel, and a coating comprising said at least one ultrasound-absorptive material overlying said stent framework and characterized by being heatable by ultrasound at a faster rate than living soft tissue.
Claim 4
Dependent Claim
12 words
The stent of claim 2 wherein said stent framework is wire mesh.
Claim 5
Dependent Claim
37 words
The stent of claim 2 wherein said at least one ultrasound-absorptive material has a heating rate greater than 0.86° C. per minute when subjected to an ultrasound beam of 1 mHz frequency and 1 Watt/cm 2 intensity.
Claim 6
Dependent Claim
13 words
The stent of claim 2 wherein said coating further comprises a heat-releasable drug.
Claim 7
Dependent Claim
44 words
The stent of claim 2 wherein said coating comprises at least two ultrasound-absorptive layers, one said layer overlying at least one other layer, said layers having dissimilar acoustic impedance characteristics and together enhancing the ultrasound-induced temperature increase of said stent when exposed to ultrasound.
Claim 8
Dependent Claim
22 words
The stent of claim 2 wherein said coating is characterized by a temperature increase of 1-5° C. in response to ultrasound irradiation.
Claim 9
Dependent Claim
59 words
The stent of claim 2 wherein said stent is configured to contact a region of vessel wall, and said coating is further characterized by having an acoustic impedance greater than that of any intervening tissue between said stent and an external ultrasound transducer, when said stent is situated in a vessel and ultrasonic radiation is directed onto said stent.
Claim 10
Dependent Claim
14 words
The stent of claim 1 wherein said at least one material is a polymer.
Claim 11
Dependent Claim
23 words
The stent of claim 9 wherein said polymer is chosen from the group consisting of silicone, polyvinylchloride, polyurethane, nylon, phosphorylcholine and combinations thereof.
Claim 12
Independent Claim
71 words
A method of making an ultrasonically heatable stent comprising: obtaining a stent framework configured for maintaining patency of a vessel; obtaining a biocompatible coating material characterized by having an acoustic impedance greater than that of human soft tissue; applying a coating of said material to said stent framework, said coating being of such thickness and character that said stent is heatable by ultrasound at a faster rate than human soft tissue.
Claim 13
Independent Claim
71 words
A method of making an ultrasonically heatable stent comprising: obtaining a stent framework configured for maintaining patency of a vessel; obtaining a biocompatible coating material characterized by having an acoustic impedance greater than that of human soft tissue; applying a coating of said material to said stent framework, said coating being of such thickness and character that said stent is heatable by ultrasound at a faster rate than human soft tissue.
Claim 14
Dependent Claim
29 words
The method of claim 11 wherein said obtaining a biocompatible coating material comprises choosing a material from the group consisting of silicone, nylon, polyvinylchloride, polyurethane, phosphorylcholine, and combinations thereof.
Claim 15
Dependent Claim
43 words
The method of claim 11 wherein said step of obtaining a biocompatible coating material includes choosing a material having a heating rate greater than 0.86° C. per minute when subjected to an ultrasound beam of 1 mHz frequency and 1 Watt/cm 2 intensity.
Claim 16
Dependent Claim
84 words
The method of claim 11 wherein said step of applying a coating of said material to said stent framework comprises applying at least two layers of coating material, each said layer chosen from the group of materials consisting of silicone, polyvinylchloride, nylon, polyurethane, phosphorylcholine, and combinations thereof, said coating being of such thickness and character that said stent is heatable by ultrasound at a faster rate than human soft tissue whereby a temperature about 1-5° C. above ambient temperature is induced in said stent.
Claim 17
Dependent Claim
103 words
A method of treating an atherosclerotic plaque in a living subject comprising: obtaining the ultrasonically heatable stent of claim 1 ; positioning said stent in a vessel lumen so as to contact a region of vessel wall comprising an atherosclerotic plaque; advantageously positioning at least one ultrasound transducer external the body of said subject; and operating said ultrasound transducer such that an ultrasonic beam is directed at said stent, whereby the temperature of said stent is maintained at about 1-5° C. above ambient temperature for a sufficient period of time to heat said region of vessel wall at a temperature of 38-42° C.
Claim 18
Dependent Claim
41 words
The method of claim 15 further comprising: measuring the temperature of said region of vessel wall; and employing a microprocessor and visual display system to control the operation of said ultrasound transducer and to receive, analyze and display said temperature measurements.
Claim 19
Dependent Claim
20 words
The method of claim 15 wherein said ultrasonic beam is directed using an acoustic lens to focus the ultrasound beam.
Claim 20
Dependent Claim
41 words
The method of claim 15 wherein two or more ultrasound transducers are advantageously positioned external the body of said subject and wherein said ultrasound transducers are operated in cooperation such that at least two ultrasonic beams are directed at said stent.
Claim 21
Dependent Claim
34 words
The method of claim 15 wherein said step of advantageously positioning an ultrasound transducer external the body of said subject is omitted and the step of positioning at least one transducer inside the esophagus.
Claim 22
Dependent Claim
37 words
The method of claim 15 wherein said step of advantageously positioning an ultrasound transducer external the body of said subject is omitted and the step of positioning an intravascular ultrasound transducer inside said stent is substituted therefor.
Claim 23
Dependent Claim
99 words
A method of treating a vascular injury comprising: obtaining the ultrasonically heatable stent of claim 1 ; positioning said stent in a vessel lumen so as to contact a region of vessel wall comprising an endoluminal vascular injury in need of treatment; advantageously positioning an ultrasound transducer inside said stent; and operating said ultrasound transducer such that an ultrasonic beam is directed at said stent, whereby the temperature of said stent is maintained at about 1-5° C. above ambient temperature for a sufficient period of time to heat said region of vessel wall at a temperature of 39-40° C.
Claim 24
Dependent Claim
26 words
The method of claim 21 wherein said step of positioning said stent in a vessel lumen comprises positioning said stent at an angioplasty or atherectomy site.
Claim 25
Dependent Claim
73 words
The method of claim 21 further comprising: subsequent to said 39-40° C. maintaining step, detecting restriction of blood flow through said stent; and operating said ultrasound transducer such that an ultrasonic beam is directed onto said stent, whereby the temperature of said stent is maintained at a temperature about 1-5° C. above ambient temperature for a sufficient period of time to heat said region of vessel wall at 42° C. for 15-30 minutes.
Claim 26
Independent Claim
124 words
A method of reducing or eliminating a population of inflammatory cells on an implanted synthetic vascular graft in a living subject comprising: advantageously positioning an ultrasound transducer external the body of said subject; and operating said ultrasound transducer such that an ultrasonic beam is directed at said synthetic vascular graft, whereby the temperature of the graft, or a portion thereof, is increased to and maintained at about 1-5° C. above ambient vessel temperature for a sufficient period of time to heat said graft or portion thereof at a temperature of 38-42° C., provided that said synthetic graft contains an ultrasound-absorptive material characterized by an acoustic impedance greater than that of human tissue and that is chemically stable when heated up to about 45° C.
Claim 27
Independent Claim
124 words
A method of reducing or eliminating a population of inflammatory cells on an implanted synthetic vascular graft in a living subject comprising: advantageously positioning an ultrasound transducer external the body of said subject; and operating said ultrasound transducer such that an ultrasonic beam is directed at said synthetic vascular graft, whereby the temperature of the graft, or a portion thereof, is increased to and maintained at about 1-5° C. above ambient vessel temperature for a sufficient period of time to heat said graft or portion thereof at a temperature of 38-42° C., provided that said synthetic graft contains an ultrasound-absorptive material characterized by an acoustic impedance greater than that of human tissue and that is chemically stable when heated up to about 45° C.
Claim 28
Dependent Claim
84 words
A method of inhibiting or regressing in-stent restenosis comprising: implanting the ultrasonically heatable stent of claim 1 into a vessel of a subject; advantageously positioning an ultrasound transducer external the body of said subject; and operating said ultrasound transducer such that an ultrasonic beam is directed at said stent, whereby the temperature of the stent is increased to and maintained at about 1-5° C. above ambient vessel temperature for a sufficient period of time to heat said stent at a temperature of 41-42° C.
Claim 29
Dependent Claim
65 words
An ultrasonically heatable stent comprising at least one ultrasound-absorptive material characterized by an acoustic impedance greater than that of living soft tissue; said stent comprising a stent framework configured to maintain patency of a human vessel; and a coating comprising said at least one ultrasound-absorptive material overlying said stent framework and characterized by being heatable by ultrasound at a faster rate than living soft tissue.
Claim 30
Dependent Claim
65 words
An ultrasonically heatable stent comprising at least one ultrasound-absorptive material characterized by an acoustic impedance greater than that of living soft tissue; said stent comprising a stent framework configured to maintain patency of a human vessel; and a coating comprising said at least one ultrasound-absorptive material overlying said stent framework and characterized by being heatable by ultrasound at a faster rate than living soft tissue.
Claim 31
Dependent Claim
73 words
An ultrasonically heatable stent comprising at least one ultrasound-absorptive material characterized by an acoustic impedance greater than that of living soft tissue; said stent comprising: a stent framework configured to maintain patency of a human vessel, and a coating comprising said at least one ultrasound-absorptive material overlying said stent framework and characterized by being heatable by ultrasound at a faster rate than living soft tissue; wherein said coating further comprises a heat-releasable drug.
Claim 32
Dependent Claim
73 words
An ultrasonically heatable stent comprising at least one ultrasound-absorptive material characterized by an acoustic impedance greater than that of living soft tissue; said stent comprising: a stent framework configured to maintain patency of a human vessel, and a coating comprising said at least one ultrasound-absorptive material overlying said stent framework and characterized by being heatable by ultrasound at a faster rate than living soft tissue; wherein said coating further comprises a heat-releasable drug.
Claim 33
Dependent Claim
26 words
The stent of claim 27 wherein said coating further comprises an ultrasonically heatable polymeric matrix and said heat-releasable drug is incorporated into the said polymeric matrix.
Claim 34
Independent Claim
54 words
A method of delivering a drug to a site in vivo, comprising the steps of: incorporating the drug into an ultrasonically heatable polymeric coating of a stent; delivering the coated stent to a specific region in vivo; and directing an external ultrasound source toward the stent, thereby heating the coating and releasing the drug.
Claim 35
Independent Claim
54 words
A method of delivering a drug to a site in vivo, comprising the steps of: incorporating the drug into an ultrasonically heatable polymeric coating of a stent; delivering the coated stent to a specific region in vivo; and directing an external ultrasound source toward the stent, thereby heating the coating and releasing the drug.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-09-16 | 2006-03-18 | 2006-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-09-16 | 2010-03-18 | 2010-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-09-16 | 2014-03-18 | 2014-09-17 | $7700.00 | Window Closed / Lapsed |