Patent Application
20180153604
The present invention relates to a tumor ablation system and method for use thereof.
Metastases are the most common cause of severe pain among patients with cancer. It has been reported that metastatic bone disease occurs in 60-80% of cancer patients.
Radiofrequency ablation is a method of treating metastatic bone disease. Radiofrequency ablation is used for the destruction of unwanted tissue, including tumors. During radiofrequency ablation, a probe is inserted into the unwanted tissue. A pair of electrodes are located at the end of the probe which is inserted into the unwanted tissue. The opposite end of the probe is connected to a radiofrequency generator which sends radiofrequency energy through the electrodes causing the immediately adjacent tissue to heat up. Once the unwanted tissue reaches a sufficient temperature for a specific period of time, the tissue dies. Radiofrequency ablation of a tumor takes about 20-30 minutes.
Currently available systems for radiofrequency ablation include probes having two electrodes located at the distal end of the probe. The currently available systems either have only one temperature sensor located near the distal end of the probe or rely on a separate temperature sensor that requires a separate incision for insertion into the patient. The currently available systems can be used with two probes. However, they do not transmit radiofrequency energy from one probe to the other. They merely insert two probes, each of which transmits radiofrequency energy between the two electrodes on that probe, and rely on the conduction of heat by the bone to ablate the bone between the two probe tips. Accordingly, the prior art systems are not capable of ablating irregular shapes or larger spaces without repositioning the probes.
The present invention is directed to a system and method of radiofrequency tumor ablation that enables ablating irregular shapes by utilizing directional application of radiofrequency energy. The system includes a pair of probes wherein each of the probes includes two electrodes and three temperature sensors. The electrodes are connected to a radiofrequency generator configured to transmit radiofrequency energy between any pair of the four electrodes. The system may include channels through the probes, enabling the circulation of cooling fluid to help prevent singeing the tissue immediately adjacent the probes. The system may also include a grounding pad that includes a return electrode for placement outside the patient. The grounding pad may be used as a return electrode for any of the four electrodes.
A system for use in ablation, in accordance with one embodiment, includes a pair of probes, each probe having a distal end, a proximal end, and a length between the distal and proximal ends. Each of the probes includes a first temperature sensor proximate the distal end of the probe, a first electrode proximal of the first temperature sensor, a first insulated section proximal of the first electrode, a second temperature sensor disposed on the first insulated section, a second electrode proximal of the first insulated section, a second insulated section proximal of the second electrode, and a third temperature sensor disposed on the second insulated section. The pair of probes are connectable to a radio frequency generator, wherein the radiofrequency generator is configured to transmit radiofrequency energy between any pair of the four electrodes. The six temperature sensors are configured to transmit temperature data to a processor, wherein the processor is configured to control which pair of electrodes is utilized by the frequency generator and the amount of radiofrequency energy delivered.
The system further contemplates the radiofrequency generator including a processor programed to automatically adjust the amount of energy transmitted between the electrodes based on the temperature readings registered by the temperature sensors. The processor may also be programed to automatically change the pair of electrodes being utilized to achieve a specific ablation pattern.
A method for use in ablation includes making two incisions in the skin of the patient, inserting two cannulas through the incisions to abut the target bone, inserting a cutting tool through the cannulas to create openings in the bone, inserting two probes through the cannulas, attaching the probes to the radiofrequency generator, attaching the probes to the reservoirs, and applying radiofrequency energy between any pair of the electrodes.
A method for use in ablation, in accordance with one embodiment, includes making a first incision and a second incision in skin of a patient, creating a first opening and a second opening in a bone, inserting a first probe including a first electrode and a second electrode through the first incision and into the first opening, inserting a second probe including a third electrode and a fourth electrode through the second incision and into the second opening, attaching the first and second probes to a radiofrequency generator via a pair of cables, ablating tissue by applying radiofrequency energy between a first pair of electrodes, ablating additional tissue by applying radiofrequency energy between a second pair of electrodes, and removing the first and second probes.
The method further contemplates a processor automatically adjusting the amount of energy transmitted between the electrodes based on the temperature readings registered by the temperature sensors and automatically changing the pair of electrodes being utilized to achieve a specific ablation pattern.
These and other objects of the present invention will be apparent from review of the following specification and the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to explain the objects, advantages, and principles of the invention.
The detailed description of the invention below is described for, and shown in the figures for, use in a vertebral body V. However, it should be understood that the invention could be used for tumor ablation in any bone.
As shown in
The temperature sensors 106, 108, 110, 206, 208, 210 may comprise thermocouples, resistive temperature detectors, thermistors, or any other suitable type of temperature sensing device. Electrodes 102, 104, 202, 204, 902 may be constructed of titanium, nitinol, steel, platinum, or any other biocompatible electrically conductive material.
As shown in
Probes 100, 200 also include an internal channel (not shown) that begins at the proximal end of handle 116, 216, runs the length of probe 100, 200, and returns to the proximal end of handle 116, 216 for pumping a cooling fluid therethrough, wherein the cooling fluid is preferably sterile water. The cooling fluid serves to cool the surface of the electrodes 102, 104, 206, 208 to prevent singeing of the tissue adjacent thereto. Probes 100, 200 may further include one or more radiopaque markers adjacent electrodes 102,104, 202, 204 to aid in the visibility of the locations of electrodes 102,104, 202, 204 while inserting probes 100, 200 into the bone under surgical imaging, such as fluoroscopy.
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For example, as shown in
The processor controlling the radiofrequency generator may be preprogramed to automatically adjust the amount and duration of radiofrequency energy applied between any pair of electrodes 102, 104, 202, 204, 902 based on temperature data received by the processor from the temperature sensors 106, 108, 110, 206, 208, 210, 906. The surgeon may interact with the processor through a touchscreen 1002. Touchscreen 1002 may also be connected to an imaging device, such as a fluoroscope, to display the target area on touchscreen 1002. The processor may also be preprogrammed to recognize the locations of probes 100, 200 on the screen. This may be accomplished through image recognition technology, aided by the presence of the radiopaque markers adjacent electrodes 102,104, 202, 204. After inserting probes 100, 200 relative to the tumor, the surgeon may outline the tissue to be ablated on the touchscreen and the processor will automatically determine which pairs of electrodes 102, 104, 202, 204, 902 to utilize, the amount of radiofrequency energy to apply to each pair, and the duration of radiofrequency energy application based on the orientation of probes 100, 200, the distance between electrodes 102, 104, 202, 204, 902, the shape and orientation of the tissue to be ablated relative to electrodes 102, 104, 202, 204, 902, and temperature data received from temperature sensors 106, 108, 110, 206, 208, 210, 906.
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As shown in
In a preferred embodiment of the present invention, the system is utilized in the following manner. The preferred method includes placing the patient in the prone position and making a pair of contralateral incisions in the skin over the target vertebral body V. The surgeon then inserts cannulas 300, 400 through the incisions into contact with the outer surface of vertebral body V. The surgeon may manipulate the positioning of cannulas 300, 400 by grasping handles 304, 404, preferably under fluoroscopy to verify correct placement of the cannulas.
The surgeon then introduces a bone removal tool, such as a drill or reamer, through cannulas 300, 400 to a desired depth. The desired depth of the bone removal tool may be controlled by utilizing a series of depth markers on the proximal end of the bone removal tool. After creating two openings in the bone, the surgeon inserts probe 100 into one of the openings and inserts probe 200 into the other of the openings. The surgeon then verifies correct placement of probes 100, 200 in relation to the tumor via use of an imaging device. The surgeon then connects cables 500, 600 and tubes 700, 800 to the proximal ends of handles 116, 216 of probes 100, 200. The opposite ends of tubes 700, 800 are attached to reservoirs 1102, 1104 and the opposite ends of cables 500, 600 are attached to radiofrequency generator 1000. The surgeon may also place grounding pad 900 on the outside of the patient's skin.
In a preferred embodiment, the surgeon views the fluoroscope image on touchscreen 1002, showing vertebral body V with probes 100, 200 inserted on opposite sides of the tumor. And the surgeon may then trace the exterior boundary of the tumor on touchscreen 1002. After the surgeon inputs the tumor boundary, the processor runs an algorithm to determine which pair(s) of electrodes 102, 104, 202, 204, 902 should be used, the amount of radiofrequency energy to be applied, and the duration of the application. The processor continually monitors the temperature data received from temperature sensors 106, 108, 110, 206, 208, 210, 906, 1200 and automatically adjusts which electrodes 102, 104, 202, 204, 902 are utilized, the amount of radiofrequency energy applied, and the duration. When the ablation is complete, the radiofrequency generator produces an audible and visual signal to signify completion.
Alternatively, the surgeon can manually select the preferred electrodes 102, 104, 202, 204, 902 to be utilized, the amount of radiofrequency energy applied, and the duration. The surgeon may watch real-time temperature outputs from temperature sensors 106, 108, 110, 206, 208, 210, 906, 1200 and manually make the necessary adjustments.
After completion of the desired ablation, the surgeon removes probes 100, 200. At this point, if indicated, the surgeon may perform vertebroplasty or Kyphoplasty through the already placed cannulas 300, 400. If not indicated, or after performing the vertebroplasty or Kyphoplasty, the surgeon removes cannulas 300, 400 and closes the incisions using an appropriate closure technique.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the embodiments described below be considered as exemplary only, with a true scope and spirit of the invention being indicated by the appended claims.
