Patent Application
20090062795
Electrical therapy techniques have been employed in medicine to treat pain and other conditions. Electrical ablation techniques have been employed in medicine to remove diseased tissue or abnormal growths, such as cancers or tumors, from the body. Electrical therapy probes comprising electrodes are employed to electrically treat diseased tissue at the tissue treatment region or target site. These electrical therapy probes comprising electrodes are usually inserted into the tissue treatment region percutaneously. There is a need for minimally invasive flexible endoscopic, laparoscopic, or thoracoscopic electrical ablation devices and methods to access a tissue treatment region, e.g., in the lungs or liver, to diagnose and treat diseased tissue more accurately and effectively using minimally invasive surgical methods. There is a need for improved flexible endoscopic, laparoscopic, or thoracoscopic electrical ablation devices that can be introduced into the tissue treatment region through a natural opening of the body or through a trocar inserted through a small incision formed in the body. The improved electrical ablation devices may be employed to electrically ablate or destroy diseased tissue at the tissue treatment region. There is a need for flexible endoscopic, laparoscopic, or thoracoscopic electrical ablation devices that include blunt dissection portions to dissect a targeted vessel from surrounding tissue. There is also a need for flexible endoscopic, laparoscopic, or thoracoscopic electrical ablation devices to thermally seal an isolated targeted vessel using electrical energy prior to transecting the targeted vessel.
In one general aspect, the various embodiments are directed to electrical ablation devices. In one embodiment, an electrical ablation device comprises an elongated flexible member having a proximal end and a distal end. A clamp jaw portion is located at the distal end of the elongated flexible member. The clamp jaw portion is operatively movable from an open position to a closed position. A blunt dissection portion is formed on the clamp jaw portion. The clamp jaw portion is adapted to couple to an electrical waveform generator and to receive an electrical waveform.
The novel features of the various embodiments are set forth with particularity in the appended claims. The various embodiments, however, both as to organization and methods of operation, together with further advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings as follows.
The various embodiments described herein are directed to electrical therapy ablation devices. The electrical therapy ablation devices comprise probes and electrodes that can be positioned in or in proximity to a tissue treatment region (e.g., target site) within a patient either endoscopically or transcutaneously (percutaneously), and, in some embodiments, a combination thereof. An electrode may be introduced into the tissue treatment region through a trocar. Other electrodes may be introduced in the tissue treatment region transcutaneously or percutaneously. The electrodes comprise an electrically conductive portion with a sharp point to facilitate insertion through the skin of a patient and to enhance local current density in the tissue treatment region during the treatment. Other electrodes may be introduced in the tissue treatment region by way of a natural orifice through a cannula or catheter. The placement and location of the electrodes can be important for effective and efficient therapy. Once positioned, the electrical therapy electrodes are adapted to deliver electrical current to the treatment region. The electrical current is generated by a control unit or generator located external to the patient. The electrical current may be characterized by a particular waveform in terms of frequency, amplitude, and pulse width. Depending on the diagnostic or therapeutic treatment rendered, the probes may comprise one electrode containing both a cathode and an anode or may contain a plurality of electrodes with at least one serving as a cathode and at least one serving as an anode.
Electrical therapy ablation may employ electroporation or electropermeabilization techniques where an externally applied electric field (electric potential) significantly increases the electrical conductivity and permeability of a cell plasma membrane. Electroporation is the generation of a destabilizing electric potential across such biological membranes. In electroporation, pores are formed when the voltage across the cell plasma membrane exceeds its dielectric strength. Electroporation destabilizing electric potentials are generally in the range of several hundred volts across a distance of several millimeters. Below certain magnitude thresholds, the electric potentials may be applied across a biological membrane as a way of introducing some substance into a cell, such as loading it with a molecular probe, a drug that can change the function of the cell, a piece of coding DNA, or increasing the uptake of drugs in cells. If the strength of the applied electrical field and/or duration of exposure to it are suitably chosen, the pores formed by the electrical pulse reseal after a short period of time; during such period, extra-cellular compounds may enter into the cell. Below a certain field threshold, the process is reversible and the potential does not permanently damage the cell membrane. This process may be referred to as reversible electroporation (RE).
On the other hand, excessive exposure of live cells to large electric fields can cause apoptosis and/or necrosis—the processes that result in cell death. Excessive exposure of live cells to large excessive electrical fields or potentials across the cell membranes causes the cells to die and, therefore, may be referred to as irreversible electroporation (IRE).
Electroporation may be performed with devices called electroporators. These appliances create the electric current and send it through the cell. Electroporators may comprise two or more metallic (e.g., aluminum) electrically conductive electrodes connected to an energy source. The energy source generates an electric field having a suitable characteristic waveform output in terms of frequency, amplitude, and pulse width.
Endoscopy refers to looking inside the human body for medical reasons. Endoscopy may be performed using an instrument called an endoscope. Endoscopy is a minimally invasive diagnostic medical procedure used to evaluate the interior surfaces of an organ by inserting a small tube into the body, often, but not necessarily, through a natural body opening or through a relatively small incision. Through the endoscope, an operator may observe surface conditions of the organs, including abnormal or diseased tissue such as lesions and other surface conditions. The endoscope may have a rigid or a flexible tube and, in addition to providing an image for visual inspection and photography, the endoscope may be adapted and configured for taking biopsies, retrieving foreign objects, and introducing medical instruments to a tissue treatment region referred to as the target site. Endoscopy is a vehicle for minimally invasive surgery.
Laparoscopic surgery is a minimally invasive surgical technique in which operations in the abdomen are performed through small incisions (usually 0.5-1.5 cm), keyholes, as compared to larger incisions needed in traditional surgical procedures. Laparoscopic surgery includes operations within the abdominal or pelvic cavities, whereas keyhole surgery performed on the thoracic or chest cavity is called thoracoscopic surgery. Laparoscopic and thoracoscopic surgery belong to the broader field of endoscopy.
A key element in laparoscopic surgery is the use of a laparoscope: a telescopic rod lens system that is usually connected to a video camera (single chip or three chip). Also attached is a fiber-optic cable system connected to a “cold” light source (halogen or xenon), to illuminate the operative field, inserted through a 5 mm or 10 mm cannula to view the operative field. The abdomen is usually insufflated with carbon dioxide gas to create a working and viewing space. The abdomen is essentially blown up like a balloon (insufflated), elevating the abdominal wall above the internal organs like a dome. Carbon dioxide gas is used because it is common to the human body and can be removed by the respiratory system if it is absorbed through tissue.
The embodiments of the electrical therapy ablation devices and techniques described herein may be employed to treat diseased tissue, tissue masses, tissue tumors, and lesions (diseased tissue) at a tissue treatment region (target site) within the body. The embodiments of the electrical therapy ablation devices and techniques described herein may be adapted to provide minimally invasive access to the tissue treatment region or anatomic location, such as lung and liver tissue, for example, to diagnose and treat the condition at the tissue treatment region more accurately and effectively. Such minimally invasive devices may be introduced into the tissue treatment region using a trocar. Once located at the target site, the diseased tissue is electrically ablated or destroyed. Some portions of the electrical therapy ablation devices may be inserted into the tissue treatment region percutaneously. Other portions of the electrical therapy ablation devices may be introduced in the tissue treatment region endoscopically (e.g., laparoscopically and/or thoracoscopically) or through small incisions. The electrical therapy ablation devices may be employed to deliver energy to the diseased tissue to ablate or destroy tumors, masses, lesions, and other abnormal tissue growths. In one embodiment, the electrical therapy ablation devices and techniques described herein may be employed in the treatment of cancer by quickly creating necrosis and destroying live cancerous tissue in-vivo. Minimally invasive therapeutic procedures to treat diseased tissue by introducing medical instruments to a tissue treatment region through a natural opening of the patient are known as Natural Orifice Translumenal Endoscopic Surgery (NOTES™).
In one embodiment, the electrical ablation system 10 may be employed in conjunction with a flexible endoscope 12 (also referred to as endoscope 12), such as the GIF-100 model available from Olympus Corporation. In one embodiment, the flexible endoscope 12, laparoscope, or thoracoscope may be introduced into the patient transanally through the colon, the abdomen via an incision or keyhole and a trocar, or through the esophagus. The endoscope 12 or laparoscope assists the surgeon to guide and position the electrical ablation system 10 near the tissue treatment region to treat diseased tissue in organs such as the liver. In another embodiment, the flexible endoscope 12 or thoracoscope may be introduced into the patient orally through the esophagus to assist the surgeon guide and position the electrical ablation system 10 near the tissue treatment region to treat diseased tissue near the gastrointestinal (GI) tract, esophagus, or lung.
In the embodiment illustrated in
The electrical ablation system 10 generally comprises an electrical ablation device 20, a plurality of electrical conductors 18, a handpiece 16 comprising an activation switch 62, and an electrical waveform generator 14 coupled to the activation switch 62 and the electrical ablation device 20. The electrical ablation device 20 comprises a relatively flexible member or shaft 22 that may be introduced to the tissue treatment region through a trocar.
One or more needle electrodes, such as first and second electrical therapy needle electrodes 24a,b, extend out from the distal end of the electrical ablation device 20. In one embodiment, the first needle electrode 24a is the negative electrode and the second needle electrode 24b is the positive electrode. The first needle electrode 24a is electrically connected to a lead such as a first electrical conductor 18a and is coupled to the negative terminal of the electrical waveform generator 14. The second needle electrode 24b is electrically connected to a lead such as a second electrical conductor 18b and is coupled to the positive terminal of the electrical waveform generator 14. Once located in the tissue treatment region, the needle electrodes 24a,b deliver electrical energy of a predetermined characteristic shape, amplitude, frequency, and duration as supplied by the electrical waveform generator 14.
A protective sleeve or sheath 26 is slidably disposed over the flexible shaft 22 and within a handle 28 portion. The sheath 26 is slideable and may be located over the needle electrodes 24a,b to protect the trocar when the electrical ablation device 20 is pushed therethrough. Either one or both of the needle electrodes may be adapted and configured in the electrical ablation device 20 to slidably move in and out of a cannula or lumen formed within a flexible shaft 22. In the illustrated embodiments, the first needle electrode 24a, the negative electrode, can be slidably moved in and out of the distal end of the flexible shaft 22 using a slide member 30 to retract and/or advance the first needle electrode 24a. The second needle electrode 24b, the positive electrode, is fixed in place. The second needle electrode 24b provides a pivot about which the first needle electrode 24a can be moved in an arc to other points in the tissue treatment region to treat large portions of diseased tissue that cannot be treated by fixing the first and second needle electrodes 24a,b in one location. The first and second electrical conductors 18a,b are provided through a handle 28 portion. The first electrical conductor 18a, which is coupled to the first needle electrode 24a, is coupled to the slide member 30. The slide member 30 is employed to advance and retract the first needle electrode 24a, which is slidably movable within a lumen formed within the flexible shaft 22. This is described in more detail in
The electrical ablation device 20 may be introduced to the desired tissue treatment region in endoscopic, laparoscopic, thoracoscopic, or open surgical procedures, as well as external and noninvasive medical procedures. Once the first and second needle electrodes 24a,b are located at respective first and second positions in the tissue treatment region, manual operation of the switch 62 of the handpiece 16 electrically connects or disconnects the needle electrodes 24a,b to the electrical waveform generator 14. Alternatively, the switch 62 may be mounted on, for example, a foot switch (not shown). The needle electrodes 24a,b may be referred to herein as endoscopic or laparoscopic electrodes. As previously discussed, either one or both of the needle electrodes 24a,b may be adapted and configured in the electrical ablation device 20 to slidably move in and out of a cannula or lumen formed within a flexible shaft 22.
In various other embodiments, transducers or sensors 29 may be located in the handle 28 portion of the electrical ablation device 20 to sense the force with which the needle electrodes 24a,b penetrate the tissue in the tissue treatment zone. This feedback information may be useful to determine whether either one or both of the needle electrodes 24a,b have been inserted in a diseased tissue region. As is well-known, cancerous tumors tend to be denser than healthy tissue and thus would require greater force to insert the needle electrodes 24a,b therein. The operator, surgeon, or clinician can physically sense when the needle electrodes 24a,b are placed within the tumor tissue in the tissue treatment zone. If the transducers or sensors 29 are employed, the information may be processed and displayed by circuits located either internally or externally to the electrical waveform generator 14. The sensor 29 readings may be employed to determine whether the needle electrodes 24a,b have been properly located in the tumor tissue thereby assuring that a suitable margin of error has been achieved in locating the needle electrodes 24a,b.
In one embodiment, the first and second needle electrodes 24a,b are adapted to receive electrical energy from a generator. The electrical energy conducted through the first and second needle electrodes 24a,b forms an electrical field at a distal end of the first and second needle electrodes 24a,b that is suitable to treat diseased tissue. In one embodiment, the electrical waveform generator 14 delivers the energy to generate the electrical field. The waveform generator 14 may be configured to generate electrical fields at a predetermined frequency, amplitude, polarity, and pulse width suitable to destroy diseased tissue cells. Application of the electrical field to the cell membranes destroys the diseased tissue located in a tissue treatment region by a process referred to as electrical ablation. The electrical waveform generator 14 may be configured to generate electrical fields in the form of direct current (DC) electrical pulses having a predetermined frequency, amplitude, and pulse width suitable to destroy cells in diseased tissues. The polarity of the DC pulses may be either positive or negative relative to a reference electrode. The polarity of the DC pulses may be reversed or inverted from positive-to-negative or from negative-to-positive any predetermined number of times to destroy the diseased tissue cells. For example, the DC electrical pulses may be delivered at a frequency in the range of 1-20 Hz, amplitude in the range of ±100 to ±1000 VDC, and pulse width in the range of 0.01-100 ms, for example. As an illustrative example, electrical waveforms having amplitude of +500 VDC and pulse duration of 20 ms may be delivered at a pulse repetition rate or frequency of 10 Hz to destroy a reasonably large volume of diseased tissue. In one embodiment, the DC polarity of the electrical pulses may be reversed by the electrical waveform generator 14. The embodiments, however, are not limited in this context.
In one embodiment, the first and second needle electrodes 24a,b are adapted to receive electrical fields in the form of an IRE waveform from an IRE generator. In another embodiment, the first and second needle electrodes 24a,b are adapted to receive a radio frequency (RF) waveform from an RF generator. In one embodiment, the electrical waveform generator 14 may be a conventional, bipolar/monopolar electrosurgical IRE generator such as one of many models commercially available, including Model Number ECM 830, available from BTX Molecular Delivery Systems Boston, Mass. The IRE generator generates electrical waveforms having predetermined frequency, amplitude, and pulse width. The application of these electrical waveforms to the cell membranes of the diseased tissue causes the diseased cells to die. Thus, the IRE electrical waveforms may be applied to the cell membranes of diseased tissue in the tissue treatment region in order to kill the diseased cells and ablate the diseased tissue. IRE electrical waveforms suitable to destroy the cells of diseased tissues are generally in the form of DC electrical pulses delivered at a frequency in the range of 1-20 Hz, amplitude in the range of +100 to +1000 VDC, and pulse width in the range of 0.01-100 ms. For example, an electrical waveform having amplitude of +500 VDC and pulse duration of 20 ms may be delivered at a pulse repetition rate or frequency of 10 HZ to destroy a reasonably large volume of diseased tissue. Unlike RF ablation systems which require high powers and energy input into the tissue to heat and destroy, IRE requires very little energy input into the tissue; rather, the destruction of the tissue is caused by high electric fields. It has been determined that in order to destroy living tissue, the electrical waveforms have to generate an electric field of at least 30,000 V/m in the tissue treatment region.
The polarity of the electrodes 24a,b may be switched electronically to reverse the polarity of the cell. Unlike conventional IRE, reversing the polarity of the electrodes 24a,b may reduce the muscular contractions due to a constant electric field generated in the tissue. Accordingly, in one embodiment, the polarity of the electrical pulses may be inverted or reversed by the electrical waveform generator 14. For example, the electrical pulses initially delivered at a frequency in the range of 1-20 Hz and amplitude in the range of +100 to +1000 VDC, and pulse width in the range of 0.01-100 ms. The polarity of the electrical pulses then may be reversed such that the pulses have amplitude in the range of −100 to −1000 VDC. For example, an electrical waveform comprising DC pulses having amplitude of +500 VDC may be initially applied to the treatment region or target site and, after a predetermined period, the amplitude of the DC pulses may be reversed to −500 VDC. As previously discussed, to destroy a reasonably large volume of diseased tissue, the pulse duration may be 20 ms and may be delivered at a pulse repetition rate or frequency of 10 HZ. The embodiments, however, are not limited in this context.
In one embodiment, the electrical waveform generator 14 may comprise a RF waveform generator. The RF generator may be a conventional, bipolar/monopolar electrosurgical generator such as one of many models commercially available, including Model Number ICC 350, available from Erbe, GmbH. Either a bipolar mode or monopolar mode may be used. When using the bipolar mode with two electrodes, one electrode is electrically connected to one bipolar polarity, and the other electrode is electrically connected to the opposite bipolar polarity. If more than two electrodes are used, the polarity of the electrodes may be alternated so that any two adjacent electrodes have opposite polarities. Either the bipolar mode or the monopolar mode may be used with the illustrated embodiment of the electrical ablation system 10. When using the bipolar mode with two needle electrodes 24a,b, the first needle electrode 24a may be electrically connected to one bipolar polarity, and the second needle electrode 24b may be electrically connected to the opposite bipolar polarity (or vice versa). If more than two electrodes are used, the polarity of the needle electrodes 24a,b is alternated so that any two adjacent electrodes have opposite polarities.
In either case, a grounding pad is not needed on the patient when using the electrical waveform generator 14 (e.g., the IRE or RF) in the monopolar mode with two or more electrodes. Because a generator will typically be constructed to operate upon sensing connection of ground pad to the patient when in monopolar mode, it can be useful to provide an impedance circuit to simulate the connection of a ground pad to the patient. Accordingly, when the electrical ablation system 10 is used in monopolar mode without a grounding pad, an impedance circuit can be assembled by one skilled in the art, and electrically connected in series with either one of the needle electrodes 24a,b that would otherwise be used with a grounding pad attached to a patient during monopolar electrosurgery. Use of an impedance circuit allows use of the IRE generator in monopolar mode without use of a grounding pad attached to the patient.
The operator, surgeon, or clinician may employ the endoscope 12 comprising at least a light source and a viewing port located at a distal end thereof to assist in visually locating the target diseased tissue region using endoscopic visualization feedback. The needle electrodes 24a,b are energized by the electrical waveform generator 14 to deliver an IRE or an RF electrical waveform that is suitable to treat the specific diseased tissue located between the first and second needle electrodes 24a,b. Locating the needle electrodes 24a,b in the tissue treatment region independently provides the operator flexibility in positioning the needle electrodes 24a,b relative to the tissue treatment region.
The electrical conductors 18a,b are electrically insulated from each other and surrounding structures except for the electrical connections to the respective needle electrodes 24a,b. The distal end of flexible shaft 22 is proximal to the first and second needle electrodes 24a,b within the field of view of the flexible endoscope 12, thus enabling the operator to see the tissue treatment region to be treated near the first and second needle electrodes 24a,b. This technique provides a more accurate way to locate the first and second needle electrodes 24a,b in the tissue treatment region.
This procedure may be repeated to destroy relatively larger portions of the diseased tissue 48. The position 60 is a pivot point about which the first needle electrode 24a may be rotated in an arc of radius “r”, which is the distance between the first and second electrodes 24a,b. Prior to rotating about the second needle electrode 24b, the first needle electrode 24a is retracted by pulling on the slide member 30 (FIGS. 1 and 2A-D) in a direction toward the proximal end and rotating the electrical ablation device 20 about the pivot point formed at position 60 by the second needle electrode 24b. Once the first needle electrode 24a is rotated to a second position 58b, it is advanced to engage the diseased tissue at point 58b by pushing on the slide member 30 in a direction towards the distal end. A second necrotic zone 62b is formed upon energizing the first and second electrodes 24a,b in the new location. A third necrotic zone 62c is formed by retracting the first needle electrode 24a, pivoting about pivot point 60 and rotating the first needle electrode 24a to a new location, advancing the first needle electrode 24a into the diseased tissue 48 and energizing the first and second electrodes 24a,b. This process may be repeated as often as necessary to create any number of necrotic zones 62n within multiple circular areas of radius “r”, for example, that is suitable to destroy the entire diseased tissue 48 region, where n is any positive integer. At any time, the surgeon or clinician can reposition both the first and second needle electrodes 24a,b and begin the process anew. Those skilled in the art will appreciate that similar techniques may be employed to treat other diseased tissue that may be accessed transanally, through the colon and/or the abdomen, and/or accessed orally through the esophagus and/or the stomach. The embodiments, however, are not limited in this context.
In one embodiment, the electrical ablation device 70 may be employed to treat diseased tissue at a target tissue site in a patient. The embodiment illustrated in
With reference now to
The electrical ablation device 70 may be employed in a method of treating cancerous tissue without destroying red blood cells. Red blood cells (erythrocytes) are not destroyed in the same manner as bi-layer lipid cells (cancerous cells). In one embodiment, the electrical ablation device 70 may be introduced through an existing endoscope, such as the endoscope 12 shown in
The flexible shaft 78 comprises first and second lumen 94a,b formed therein to slidably receive the respective first and second needle electrodes 72a,b. A flexible sheath 80 extends longitudinally from a handle portion 82 to the distal end 74. The handle portion 82 comprises a first slide member 84a and a second slide member 84b. The slider members 84a,b are received in respective slots 90a and 90b (
The electrical ablation system 70 may be introduced endoscopically through the endoscope 12. The operator inserts the flexible shaft 32 of the endoscope 12 into the anus 104 and maneuvers it through the colon 102. The operator uses endoscopic visualization through the viewing port of the endoscope 12 to position the distal end 74 of the electrical ablation device 70 at the target site of the diseased tissue 110. At the target site, the first and second needle electrodes 72a,b are inserted into the diseased tissue 110 such that they are placed in intimate contact with the diseased tissue 110 to be treated within the field of view of the flexible endoscope 12. Watching through the viewing port of the endoscope 12, the operator can actuate a switch 83 located on the handle 82 to electrically connect the electrodes 72a,b to the waveform generator 14 through a corresponding set of conductors 85 inserted through the electrical receptacle openings 86a,b. Electric current then passes through the portion of the diseased tissue 110 positioned between the electrodes 72a,b. When the operator observes that the tissue within the field of view has been sufficiently ablated, the operator deactuates the switch 83 to stop the ablation. The operator may reposition either of the endoscopic electrodes 72a for subsequent tissue treatment, or may withdraw the electrical ablation device 70 (together with the flexible endoscope 12). As previously discussed above with reference to FIGS. 1 and 2A-D, in the embodiment described in
If the diseased tissue 110 is located on the liver, the distal end of the endoscope 12 can be advanced into the sigmoid colon. Once in the sigmoid colon, an instrument such as a needle knife can be advanced through the lumen of the endoscope 12. The needle knife can then cut an opening through the sigmoid colon and into the peritoneal space (under visualization). The endoscope 12 can then be advanced into the peritoneal space and manipulated until the liver is in view. This can be done under visualization using the view from the endoscope 12 or with fluoroscopy. The electrical ablation device 70 and the first and second electrodes 72a,b are then advanced into the liver to the target site.
With reference now to
The elongated portion 122 comprises an elongated flexible member 146 coupled to the clevis 130 by a bushing coupler 142 and a ring capture 144. In one embodiment, the elongated flexible member 146 comprises a flat spring coil pipe. An inner housing coupler 162 (
First and second electrical conductors 118a,b are electrically coupled to the respective first and second electrodes 134a,b formed in the respective first and second jaw members 126a,b. In one embodiment, the first and second electrodes 134a,b may be formed having a substantially flat paddle-like shape. The first and second electrical conductors 118a,b are received through lumens formed in the multi-lumen elongated flexible member 148 and are coupled to the first and second electrodes 134a,b in any suitable manner. A switch may be coupled to the electrical conductors 118a,b to enable an operator to activate and deactivate the first and second electrodes 134a,b after tissue at the desired target site is grasped between the first and second jaw members 126a,b.
In one embodiment, the electrical ablation device 120 may be employed to treat diseased tissue at a target tissue site in a patient. The embodiment illustrated in
In the embodiment illustrated in
A pad electrode 265b comprising an electrically conductive pad is located on an exterior or outside portion 232 of the breast 222. The pad electrode 265b has a much larger surface area than the balloon member 265a of the needle electrode 263. In one embodiment, the balloon member 265a of the needle electrode 263 and the pad electrode 265b are adapted to receive an electrical field generated by the electrical waveform generator 14. In one embodiment, the electrical field is in the form of an IRE waveform generated by an IRE generator. In another embodiment, the electrical field is in the form of a RF waveform generated by an RF generator. The needle electrode 263 is connected to the waveform generator 14 through a first lead 234a, and the pad electrode 265b is connected to the waveform generator through a second lead 234b. In the illustrated embodiment, the needle electrode 263 is connected to a positive output of the waveform generator 14, and the pad electrode 265b is connected to a negative output of the waveform generator 14. As previously discussed, the electrical waveform generator 14 is capable of generating high voltage pulse waveforms of various amplitude, frequency, and pulse duration. In other embodiments, the polarity of the needle electrode 263 and the pad electrode 265b may be inverted. Multiple pulses may be supplied to the needle electrode 263 and the pad electrode 265b to destroy cancerous tissue at a certain depth of the space 267 near the target zone 269. A pulse train 268 comprising 20 to 40 pulses of ±500 to ±700 VDC of approximately 0.4 milliseconds in duration each is sufficient to destroy the cancerous tissue 226. As previously discussed, in one embodiment, the polarity of the electrical pulses may be inverted or reversed by the electrical waveform generator 14 during the treatment process.
The techniques discussed above with reference to
A lung tumor 272 is shown in the left lung 274b. The lung tumor 272 can be difficult to resect surgically. A first catheter 276a is introduced through a wall 279 of the esophagus 278, through lung tissue 280, and is located next to the tumor 272. A second catheter 276b is introduced through the trachea 282 and is located next to the tumor 272. The first and second catheters 276a,b are independently steerable. The first and second catheters 276a,b may be formed as hollow flexible tubes for insertion into a body cavity, duct, or vessel comprising first and second lumen to receive respective first and second elongated electrical conductors 284a,b therethrough. Each one of the first and second elongated electrical conductors 284a,b comprise a metal portion that extends beyond the distal end of the respective first and second catheters 276a,b. The proximal ends of the first and second electrical conductors 284a,b are coupled to the output electrodes of the waveform generator 14.
Electrical ablation by applying a suitable electrical field as discussed above is an effective way to destroy the lung tumor 272. In one embodiment, the first and second electrical conductors 284a,b are adapted to receive an IRE waveform from an IRE generator. In another embodiment, the first and second electrical conductors 284a,b are adapted to receive a RF waveform from an RF generator. Radio frequency ablation supplies energy into the cancerous tissue of the tumor 272 to raise its temperature and destroy the tumor 272. IRE employs high voltage DC pulses to destroy the tumor 272. The exposed metal portions of the electrical conductors 284a,b located within the respective first and second catheters 276a,b are located near the tumor 272, and high voltage DC pulses are applied to the cancerous tissue of the tumor 272 to destroy it. In one embodiment, the pulses may be extremely short in duration (˜5 microseconds) and may be applied in multiple bursts such as 20 to 40 pulses, for example. The voltage amplitude or energy of each pulse is sufficient to cause damage to the cells at the target site (e.g., cancerous tissue forming the tumor 272) by necrosis or inducing apoptosis, as discussed above. Both the first and second catheters 276a,b may be introduced through the esophagus 278, the trachea 282, the skin 286 or any combination thereof. As previously discussed, in one embodiment, the polarity of the electrical pulses may be inverted or reversed by the electrical waveform generator 14 during the treatment process.
With reference to
The electrical ablation probe 296 has a form factor that is suitable to be located into a tapered lumen 298 of the vessel 292. The probe 296 engages the vessel wall 294 as it is inserted within the tapered lumen 299 of the vessel 292. Suction 306 applied at a proximal end of the probe 296 draws a vacuum within the lumen 300 of the probe causing the vessel 292 to collapse at the distal end 298 of the probe 296.
Once the vessel 292 is collapsed or pulled down by the suction 306, a first pulse train 302 comprising high voltage DC pulses of a first amplitude A1 (e.g., ˜1 KV amplitude) and a first pulse duration T1 (e.g., ˜50 microseconds) is applied to the first and second ring electrodes 300a,b by the electrical waveform generator 14. The high voltage DC pulse train 302 eventually causes the cells to die. A second pulse train 304 having a lower voltage amplitude A2 (e.g., ˜500 VDC) and a second pulse duration T2 (e.g., ˜15 milliseconds) is applied to the first and second ring electrodes 300a,b of the probe 296 to cause thermal damage and thermally seal the vein 292. As previously discussed, in one embodiment, the polarity of the electrical pulses may be inverted or reversed by the electrical waveform generator 14 during the treatment process.
The electrical ablation device 400 comprises an elongated flexible portion 422 and a clamp jaw portion 424. The clamp jaw portion 424 comprises a first jaw member 426a and a second jaw member 426b. The outer portion 472 of the first jaw member 426a is tapered to form the blunt dissection portion 402. In other embodiments, either or both first and second jaw members 426a,b may be tapered to form the blunt dissection portion 402. In one embodiment, the tapered outer portion 472 of the first jaw member 426a comprises a tissue gripping surface comprising a plurality of notches 476 (e.g., serrations or teeth). In one embodiment, the plurality of notches 476 may be formed on the tapered outer portion 472 of the first jaw member 426a. The notches 476 act as tissue gripping surfaces to securely grip tissue and facilitate dissection of tissue surrounding the blunt dissection portion 402. In another embodiment, the second jaw member 426b may comprise a tissue gripping surface comprising a plurality of notches (e.g., serrations or teeth) formed on an outer portion thereof to grip tissue and facilitate dissection. Inner portions of the first and second jaw members 426a,b may comprise a plurality of serrations 452a,b or teeth to grasp targeted tissue between the first and second jaw members 426a,b.
The first jaw member 426a comprises an electrode portion 434a (not shown), an electrical insulator portion 436a (not shown), and a tissue gripping surface comprising the plurality of notches 476 formed on the tapered outer portion 472. The first electrode portion 434a and the first electrical insulator portion 436a are analogous to the first electrode portion 134a and the first electrical insulator portion 136a shown in
In the illustrated embodiment, the clamp jaw portion 424 is substantially analogous to the clamp jaw portion 124 discussed above with reference to
The first and second jaw members 426a,b are operatively coupled to the actuator 440 via an elongated actuator member 450. The first and second jaw members 426a,b cooperate and act like forceps, tongs, or paddle-like graspers to grasp and engage targeted tissue with the serrations 452a,b and containing the tissue between the first and second jaw members 426a,b. The elongated actuator member 450 is provided within one of the lumens formed within the multi-lumen elongated flexible member 448. The elongated actuator member 450 may be formed as a solid rod or a tube. The elongated actuator member 450 is coupled to the actuator 440 and is reciprocally movable to open and close the first and second jaw members 426a,b. The elongated actuator member 450 is reciprocally movable in the directions indicated by arrows 454 and 458. When the elongated actuator member 450 is moved in the direction indicated by arrow 454, the first and second jaw members 426a,b open in the direction indicated by arrow 456. When the elongated actuator member 450 is moved in the direction indicated by arrow 458, the first and second jaw members 426a,b close in the direction indicated by arrow 460.
With reference now to
First and second electrical conductors 418a,b are electrically coupled to the respective first and second electrodes 434a,b formed in the respective first and second jaw members 426a,b. In one embodiment, the first and second electrodes 434a,b may be formed having a substantially flat paddle-like shape. The first and second electrical conductors 418a,b are received through lumens formed in the multi-lumen elongated flexible member 448 and are coupled to the first and second electrodes 434a,b in any suitable manner. A switch may be coupled to the electrical conductors 418a,b to activate and deactivate the first and second electrodes 434a,b after tissue, e.g., a blood vessel, is grasped between the first and second jaw members 426a,b.
In one embodiment, the first and second electrodes 434a,b are adapted to receive an electrical field such as an IRE waveform from a suitable IRE waveform generator. In another embodiment, the first and second electrodes 434a,b are adapted to receive a RF waveform from a suitable RF waveform generator. In one embodiment, the first and second electrodes 434a,b are connected to the electrical waveform generator 14 such as a high voltage DC waveform generator (±500 VDC), for example. It has been shown that when high electric fields are applied to tissue, the cell membrane will form an aqueous pathway through which molecules can flow (electroporation). If the electric field is increased to a sufficient level, the wall of the cell will rupture and subsequent apoptosis/necrosis will occur (irreversible electroporation). This occurs on the order of 1 millisecond; therefore, very little energy is put into the tissue and very little heating occurs. Therefore, the tissue can be treated more precisely and safely with the electrical ablation device 400 than complete removal or thermal destruction of the diseased mucosal tissue. As previously discussed, in one embodiment, the polarity of the electrical pulses may be inverted or reversed by the electrical waveform generator 14 during the treatment process.
The tapered outer portion 472 of the distal end 478 of the clamp jaw portion 424 may be burrowed into tissue proximal to a vessel to be dissected. By burrowing the distal end 478 of the clamp jaw portion 424 and repeatedly opening and closing the first and second jaw members 426a,b, a small hole may be torn in the tissue near the vessel. The small hole may be enlarged by inserting the clamp jaw portion 424 into the small hole and repeatedly opening and closing the first and second jaw members 426a,b. When the first and second jaw members 426a,b are opened, the plurality of notches 476 formed on the tapered outer portion 472 of the first jaw member 426a securely grip the tissue upon to facilitate dissection. After separating the vessel from the surrounding connective tissue using the blunt dissection portion 402 and repeatedly opening and closing the first and second jaw members 426a,b, the isolated vessel may be grasped within the first and second jaw members 426a,b of the clamp jaw portion 424. The vessel may be thermally sealed by energizing the first and second electrodes 434a,b with energy supplied by the electrical waveform generator 14, either in bipolar or monopolar mode. Once a suitable thermal seal is formed in the clamped portion of the vessel, the clamp jaw portion 424 may be opened and removed from the vessel. The vessel may be cut using conventional cutting instruments.
In use, the electrical ablation device 400 with the blunt dissection portion 402 may be employed to bluntly dissect out a vessel from surrounding connective tissue. In one method, for example, the electrical ablation device 400 with the blunt dissection portion 402 may be inserted through the working channel of a flexible endoscope. The tapered outer portion 472 of the distal end 478 of the clamp jaw portion 424 is located in proximity to the vessel to be dissected. The tapered outer portion 472 of the distal end 478 of the clamp jaw portion 424 is burrowed into the proximal tissue to form a small hole. With the distal end 478 of the clamp jaw portion 424 located in the small hole, the first and second jaw members 426a,b of the clamp jaw portion 424 are repeatedly opened and closed within the small hole to enlarge the small hole. The plurality of notches 476 are formed on the tapered outer portion 472 of the first jaw member 426a to engage and securely grip the tissue to facilitate dissection of the vessel from the surrounding tissue. The isolated vessel dissected from the surrounding connective tissue is grasped within the first and second jaw members 426a,b of the clamp jaw portion 424. The clamped vessel may be thermally sealed by energizing the first and second electrodes 434a,b with energy supplied by the electrical waveform generator 14. The electrical waveform generator 14 may be operated in monopolar or bipolar mode. Once the thermal seal is formed, the clamp jaw portion 424 is opened and removed from the vessel. The vessel is cut using conventional cutting instruments.
The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.
Preferably, the various embodiments described herein will be processed before surgery. First, a new or used instrument is obtained and, if necessary, cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK® bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.
It is preferred that the device is sterilized. This can be done by any number of ways known to those skilled in the art including beta or gamma radiation, ethylene oxide, or steam.
Although the various embodiments have been described herein in connection with certain disclosed embodiments, many modifications and variations to those embodiments may be implemented. For example, different types of end effectors may be employed. Also, where materials are disclosed for certain components, other materials may be used. The foregoing description and following claims are intended to cover all such modifications and variations.
Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
This application is a continuation-in-part application of application Ser. No. 11/897,676, filed Aug. 31, 2007, titled “ELECTRICAL ABLATION SURGICAL INSTRUMENTS”; a continuation-in-part application of application Ser. No. 11/986,420, filed Nov. 21, 2007, titled “BIPOLAR FORCEPS”; and a continuation-in-part application of application Ser. No. 11/986,489, filed Nov. 21, 2007, titled “BIPOLAR FORCEPS HAVING A CUTTING ELEMENT”; the disclosure of each of these applications is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11897676 | Aug 2007 | US |
| Child | 12109699 | US | |
| Parent | 11986420 | Nov 2007 | US |
| Child | 11897676 | US | |
| Parent | 11986489 | Nov 2007 | US |
| Child | 11986420 | US |
