Ablation device

An electrosurgical device includes a needle with an interior surface defining a lumen and a first electrode positioned within the lumen of the needle in a first position. The first electrode is movable within the needle between the first position and a plurality of other positions. The first electrode extends beyond a distal end of the needle in the plurality of other positions and includes one or more anchors that pierce into a predetermined portion of tissue in an anatomy of a patient. The first electrode is energized to ablate the predetermined portion of tissue with the first electrode.

FIELD

The present disclosure relates to an electrosurgical device. More specifically, the present disclosure relates to an ablation device with anchoring features.

BACKGROUND

Lung nodules, lesions, tumors, and other cancerous or precancerous regions of tissue in the lung may be difficult to treat with invasive surgical techniques, with attendant complications such as excessive bleeding, infection risk, air leaks, pneumothorax, and other such issues. In particular, regions deep in the lung may be difficult to access using conventional methods, further increasing the difficulty of treatment.

It is contemplated that the device of the present invention may also be used to treat nodules, lesions, tumors, and other cancerous or precancerous regions of tissue in any other region of the body where an endoscope may be inserted, used for diagnostic purposes, or along with therapeutic instrumentation, including the gastrointestinal tract, sinus passages and the urinary system, for example.

The current methods for tissue coagulation involves either placing the electrode in a single location and coagulate or moving it to different locations in the target to coagulate in order to improve coagulation volume, improve the margin around the target, and produce a more spherical coagulation. However, the placement algorithm used in these tech geeks is ambiguous and may not solve issues with over-penetration affecting the coagulation volume or efficiency, nor does it specify a consistent method to reproduce the coagulation zone. The major issue with single location coagulation is that there is a diminishing effect of coagulation through the application of high-frequency electromagnetic energy when attempting to increase the coagulation volume. The coagulation volume is also highly susceptible to the shape and orientation of the electrode(s). These issues arise from the limitations occurring in the conductivity of the tissue decreases as it is coagulated and the electrical path increasing in length, resulting in greater impedance and significantly lower efficiency.

SUMMARY

The present invention provides an improved medical device with at least one electrode that is energized to ablate a predetermined portion of tissue in a patient.

Accordingly, pursuant to one aspect of the invention, there is contemplated a medical device that includes a needle with an interior surface defining a lumen and a first electrode positioned within the lumen of the needle in a first position. The first electrode is movable within the needle between the first position and a second position. The first electrode extends beyond a distal end of the needle in the second position and includes one or more anchors that pierce into a predetermined portion of tissue in an anatomy of a patient. The first electrode is energized to ablate the predetermined portion of tissue with the first electrode.

The medical device may be further characterized by one or any combination of the features described herein, such as, for example: the needle serves as a second electrode, the first electrode and the needle arranged to deliver a desired level of energy to the predetermined portion of tissue when the first electrode is in the second position to ablate the predetermined portion of tissue; the medical device further includes an insulator that electrically isolates the needle from the first electrode; the needle has echogenic features on the exterior of the needle; the echogenic features are a plurality of circular slots spaced apart along a portion of the exterior of the needle; the first electrode is attached to a wire that extends through the lumen of the needle; the wire is made of a shape memory alloy; the shape memory alloy is nitinol; the first electrode is attached to the wire with a tube crimped to the first electrode and the wire; the tube includes echogenic features; the echogenic features are a plurality of dents distributed about the exterior of the tube; and at least one of the one or more anchors includes a tip that pierces into the predetermined portion of tissue and a curved member that latches onto the predetermined portion of tissue to secure the first electrode to the predetermined portion of tissue.

In another aspect, the present disclosure provides a method of treating a predetermined portion of tissue in a patient's anatomy including one or more of the following steps: positioning a first electrode within a lumen of a needle; positioning a distal end of the needle at the predetermined portion of tissue; retracting the needle relative to the first electrode so that the first electrode extends beyond the distal end of the needle, the first electrode including one or more anchors that pierce into the predetermined portion of tissue; and energizing the first electrode to ablate the predetermined portion of tissue with the first electrode.

The method may be further characterized by one or any combination of the features described herein, such as, for example: the needle serves as a second electrode, the first electrode and the needle arranged to deliver a desired level of energy to the predetermined portion of tissue when the first electrode is in the second position to ablate the predetermined portion of tissue; and at least one of the one or more anchors includes a tip that pierces into the predetermined portion of tissue and a curved member that latches onto the predetermined portion of tissue to secure the first electrode to the predetermined portion of tissue.

A method of coagulation used during coagulation. The technique utilizes the needle track created during penetration into the target to coagulate along the needle path, starting at the deepest location first, then procedurally coagulating at locations along the needle path that are closer to the initial penetration location. This method creates a more consistent and reproducible coagulation volume, while reducing the limitations of high tissue impedance.

DETAILED DESCRIPTION

Referring now to the drawings, an electrosurgical device embodying the principles of the present invention is illustrated inFIGS. 1A and 1Bdesignated at10. The electrosurgical device10includes an electrode handle12and a needle handle14positioned within the electrode handle12. A set of leads11extend from the electrode handle12and the needle handle14to, for example, a controller, as well as a power supply that is selectively controlled to energize the electrosurgical device10. The electrode handle12is coupled to a sheath clamp22with a depth setter20. The electrosurgical device10further includes an adapter26that enables the electrosurgical device to be connected to an instrument, such as, for example, a bronchoscope.

Referring further toFIG. 2, a needle30is connected to the needle handle14and extends through a sheath28coupled to the sheath clamp22. The sheath28is coupled to the needle handle14with a depth setter20. After advancing the sheath28to a desired location, an operator of the electrosurgical device10, such as a physician, is able to lock the sheath clamp22to the sheath by tightening a sheath screw24to set the sheath28. The electrode handle12is movable relative to the depth setter20along a set of notches21. An indicator, such as a set of numbers23, provides a visual reference to the operator as to the depth of the electrode31. To lock the position of the needle30, the operator tightens a needle handle screw16, and to lock the position of an electrode31at a desired depth, the operator tightens an electrode handle screw18into a particular notch of the set of notches21. Operation of the electrosurgical device10is described in greater detail below.

The needle30has a distal end with a point34and an interior surface that devices a lumen36. The electrode31is positioned within the lumen36. The electrode31is moveable relative to the needle30such that in a first position the electrode's distal end resides within the lumen36and in a second position the electrode's distal end extends beyond the distal end of the needle30as illustrated inFIG. 2.

The electrode31includes a wire38connected to a pair of anchors46A and46B with a tube44crimped to the wire38and the anchors46A and46B. An insulator42surrounds the wire38to electrically isolate the needle30from the electrode31. In various implementations, either or both the needle30and the tube44include echogenic features for visualization of the needle30and the electrode31. For example, the needle30can include echogenic features such as, for example, a plurality of circular slots32spaced apart along a portion of the exterior of the needle30, that the tube44can include echogenic features such as, for example, a plurality of dents40distributed about the exterior surface of the tube44. Metals such as stainless steel or a shape memory alloy, such as nitinol, can be used to manufacture the needle30or the wire38. Such materials may be well visualized under X-ray or fluoroscopy. In cases where no ultrasound is provided at the distal end of an endoscope, for example, positioning of the electrodes can be accomplished using X-ray or fluoroscopy alone.

In the arrangement shown inFIG. 2, each anchor46A,46B includes a curved member48A and48B, respectively, which latches the anchors46A and46B onto a predetermined portion of tissue of a patient. The anchors46A and46B further include piercing members50A and50B with tips52A and52B that pierce into the predetermined portion of tissue.

Other arrangements for an electrode are contemplated as well. For example, as shown inFIG. 3, an electrode131includes three anchors146A,146B, and146C. Each anchor146A,146B,146C includes a curved member148A,148B, and148C, respectively, that latches the anchors146A,146B, and146C onto a predetermined portion of tissue of a patient. The anchors146A,146B, and148C further include piercing members150A,150B, and150C with tips152A,152B, and152C that pierce into the predetermined portion of tissue.

In yet another arrangement, as shown inFIG. 4, an electrode231includes three anchors246A,246B,246C, and246D. Each anchor246A,246B,246C,246D includes a curved member248A,248B,248C, and248D respectively, that latches the anchors246A,246B,246C, and246D onto a predetermined portion of tissue of a patient. The anchors246A,246B,248C, and248D further include piercing members250A,250B,250C, and250D with tips252A,252B,252C, and252D that pierce into the predetermined portion of tissue.

In various other arrangements, the electrode can include as few as a single anchor or more than four anchors. With any of the electrode arrangements, the electrode31,131, or231functions as a first electrode and the needle30functions as a second electrode. As such, referring toFIG. 5, there is shown a process300with a sequence of steps to operate the electrosurgical device10.

In a first step302, the physician positions the first electrode31,131, or231within the needle30. Subsequently, in a step304, the physician positions the distal tip34of the needle30at a predetermined portion of tissue of a patient. The physician, in a step306, then retracts the needle30and, in a step308, energizes the first electrode31,131, or231with a desired energy level to ablate the predetermined portion of tissue.

More specifically,A) to insert the needle30and the electrode31,131, or231into the predetermined portion of tissue, the operator of the electrosurgical device10such as a physician:1) tightens the needle handle screw16, which locks the electrode handle12to the needle handle14;2) with the needle30and the electrode31,131, or231retracted into the sheath28, inserts the electrosurgical device10into a bronchoscope that is already inserted into the patient, and locks the electrosurgical device10onto the bronchoscope with bronchoscope adapter26;3) advances the sheath28and tightens the sheath screw24to set the depth of the sheath28;4) loosens the electrode handle screw18and moves the electrode handle12to position the needle30into the predetermined portion of tissue;5) after positioning the needle30and the electrode31at the desired location, tightens the electrode handle screw18to lock the electrode31to the depth setter20and to prevent movement of the electrode31, such that all movable components are locked in place;6) loosens the needle handle screw16to allow the needle30to slide within the electrode handle12;7) slides the needle handle14back to expose the electrode31and tightens the needle handle screw16to lock the needle handle14in place;8) coagulates tissue using an electrical generator coupled to the electrosurgical device10;9) pumps saline through a saline manifold into the electrosurgical device10; and10) repeats steps 4-9 as necessary to coagulate the predetermined portion of tissue.B) To remove the electrosurgical device10from the patient, the physician:1) loosens the needle handle screw16and slides the needle handle14forward to fully capture the electrode31,131, or231within the needle30;2) tightens the needle handle screw16to lock the needle handle and electrode handle12together;3) loosens the electrode handle screw16and moves the electrode handle12to retract the needle30;4) tightens the electrode handle screw18down, when the needle30and the electrode31,131, or231are fully retracted back into the sheath28;5) loosens the sheath screw24, retracts the sheath, and then retightens the sheath screw24so that all movable components are locked in place;6) unlocks the electrosurgical device10from the bronchoscope with the bronchoscope adapter; and7) pulls the electrosurgical device10out of the bronchoscope.

Turning now toFIG. 6, there is shown the needle30being employed in an ablation process. The needle30exits an opening33at a distal end29of the sheath28. The needle30is inserted into a target region400in the interior region of a patient such that the operator is provided with a consistent method of using the needle30in combination with any of the aforementioned electrodes31,131, or231for coagulating tissue and creating a reproducible coagulation volume in the target region400.

In addition,FIG. 6shows an ablation process or pathline technique that takes into account issues associated with over-penetration and potential saline drainage. The pathline technique maximizes the efficiency of coagulation by ensuring that the operator moves the needle30and the electrode31,131or231as tissue conductivity decreases, effectively creating a larger coagulation volume then attempting to coagulate tissue in a single location.

More specifically, the needle30utilizes the needle track created during penetration into the target400region to coagulate tissue along a needle path402, starting at the deepest location404initially to seal the needle path. The operator retracts the needle30to, for example, a middle location406and coagulates tissue in this region if desired, and then retracts the needle30to the proximal edge408of the target region400and coagulates tissue in this region if desired. Hence, the operator is procedurally able to coagulate tissue at locations along the needle path402that are closer to the initial penetration location. The pathline technique creates a more consistent and reproducible coagulation volume, while reducing the limitations of high tissue impedance. Once a first portion of the target region has been coagulated, the operator may reinsert the needle30and the electrode31,131, or231along a second path410and coagulate in the same manner as the first path402.