Surgery – Instruments – Electrical application
Reexamination Certificate
1999-11-19
2003-11-25
Peffley, Michael (Department: 3739)
Surgery
Instruments
Electrical application
C607S101000
Reexamination Certificate
active
06652516
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a cell necrosis apparatus, and more particularly to a cell necrosis apparatus with a flexible introducer.
2. Description of the Related Art
Current open procedures for treatment of tumors are extremely disruptive and cause a great deal of damage to healthy tissue. During the surgical procedure, the physician must exercise care in not cutting the tumor in a manner that creates seeding of the tumor, resulting in metastasis. In recent years, development of products has been directed with an emphasis on minimizing the traumatic nature of traditional surgical procedures.
There has been a relatively significant amount of activity in the area of hyperthermia as a tool for treatment of tumors. It is known that elevating the temperature of tumors is helpful in the treatment and management of cancerous tissues. The mechanisms of selective cancer cell eradication by hyperthermia are not completely understood. However, four cellular effects of hyperthermia on cancerous tissue have been proposed, (i) changes in cell or nuclear membrane permeability or fluidity, (ii) cytoplasmic lysomal disintegration, causing release of digestive enzymes, (iii) protein thermal damage affecting cell respiration and the synthesis of DNA or RNA and (iv) potential excitation of immunologic systems. Treatment methods for applying heat to tumors include the use of direct contact radio-frequency (RF) applicators, microwave radiation, inductively coupled RF fields, ultrasound, and a variety of simple thermal conduction techniques.
Among the problems associated with all of these procedures is the requirement that highly localized heat be produced at depths of several centimeters beneath the surface of the skin.
Attempts to use interstitial local hyperthermia have not proven to be very successful. Results have often produced nonuniform temperatures throughout the tumor. It is believed that tumor mass reduction by hyperthermia is related to thermal dose. Thermal dose is the minimum effective temperature applied throughout the tumor mass for a defined period of time. Because blood flow is the major mechanism of heat loss for tumors being heated, and blood flow varies throughout the tumor, more even heating of tumor tissue is needed to ensure effective treatment.
The same is true for ablation of the tumor itself through the use of RF energy. Different methods have been utilized for the RF ablation of masses such as tumors. Instead of heating the tumor it is ablated through the application of energy. This process has been difficult to achieve due to a variety of factors including, (i) positioning of the RF ablation electrodes to effectively ablate all of the mass, (ii) introduction of the RF ablation electrodes to the tumor site and (iii) controlled delivery and monitoring of RF energy to achieve successful ablation without damage to non-tumor tissue.
Thus, non-invasive procedures for providing heat to internal tissue have had difficulties in achieving substantial specific and selective treatment.
Examples illustrating the use of electromagnetic energy to ablate tissue are disclosed in: U.S. Pat. Nos. 4,562,200; 4,411,266; 4,838,265; 5,403,311; 4,011,872; and 5,385,544.
There is a need for a cell necrosis apparatus with a flexible introducer. There is another need for a cell necrosis apparatus with an introducer that is flexible enough to come back upon itself. There is yet another need for a cell necrosis apparatus with an introducer that is advanceable through or around a selected target cell necrosis mass, and be flexibly positioned at any desired site in tissue.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a cell necrosis apparatus that provides tissue reduction at selected anatomical sites.
Another object of the invention is to provide a treatment apparatus to create cell necrosis.
Another object of the invention is to provide a cell necrosis apparatus with a flexible introducer.
Still another object of the invention is to provide a cell necrosis apparatus with an introducer that is flexible enough to come back upon itself.
A further object of the invention is to provide a cell necrosis apparatus with an introducer that is configured to be advanceable through or around a selected target cell necrosis mass, and be flexibly positioned at any desired site in tissue.
These and other objects of the invention are achieved in a cell necrosis apparatus with a flexible introducer including a lumen and a distal end sufficiently sharp to penetrate tissue. An energy delivery device is positionable in the introducer as the introducer is advanced through tissue. The energy delivery device includes a first RF electrode with a tissue piercing distal portion and a second RF electrode with a tissue piercing distal portion. The first and second RF electrodes are deployable with curvature from the introducer at a selected tissue site in a lateral direction away from the periphery of the introducer.
A further object of the invention is to provide a cell necrosis apparatus, with an introducer including a lumen and an energy delivery device including at least a first, a second and a third RF electrode. Each of the electrodes have a tissue piercing distal portion. The first, second and third RF electrodes are positionable in the introducer in a compacted state and deployable from the introducer with curvature in the deployed state. The first, second and third RF electrodes exhibit a changing direction of travel when advanced from the introducer to a selected tissue site. The first RF electrode may include a fluid delivery lumen and a fluid delivery port.
In another embodiment, the cell necrosis apparatus has a flexible introducer. The.energy delivery device includes a first RF electrode with a tissue piercing distal portion, a second RF electrode with a tissue piercing distal portion and a third RF electrode with a tissue piercing distal portion. The first, second and third RF electrodes are positionable in the introducer as the introducer is advanced through tissue and deployable with curvature in a radially divergent configuration when extended beyond the introducer.
REFERENCES:
patent: 5370675 (1994-12-01), Edwards et al.
patent: 5403311 (1995-04-01), Abele et al.
patent: 5855576 (1999-01-01), LeVeen et al.
patent: 6080150 (2000-06-01), Gough
Dehlinger Peter J.
Mahoney Jacqueline F.
Peffley Michael
Perkins Coie LLP
Rita Medical Systems, Inc.
LandOfFree
Cell necrosis apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cell necrosis apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cell necrosis apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3123970