Microwave tissue ablation probe using a non-metallic introducer kit

Abstract

An introducer kit for a microwave ablation probe is disclosed. The introducer kit includes: a cannula, which is at least partially transparent to microwave energy; and a stylet, which is sized to be received by the inner cavity of the cannula. Other examples provide a microwave ablation system, which includes a microwave ablation probe having a radiating portion and a cannula that is at least partially transparent to microwave energy. When the probe is inserted into the inner cavity of the cannula, the radiating portion of the probe is aligned with the transparent portion of the cannula. The present technology provides a method, which includes: introducing a microwave ablation probe into the inner cavity of a cannula, the cannula having a cannula body that is at least partially transparent to microwave energy; aligning the transparent portion of the cannula with the radiating portion of the probe; and emitting microwave energy from the radiating portion of the probe.

Description

[0001] This application was filed as a PCT international patent application on April 17, 2019, in all designated countries in the name of Boston Scientific Scimed, Inc., a U.S. state-owned corporation, as the applicant and in all designated countries in the name of U.S. citizen Hong Cao, U.S. citizen Kent David Harrison, and U.S. citizen Timothy A. Ostroot as inventors, and claims priority to U.S. Provisional Application No. 62 / 659,519 filed on April 18, 2018, and claims priority to U.S. Patent Application No. 16 / 385,994 filed on April 16, 2019, the contents of which are incorporated herein by reference in their entirety. Background Art

[0002] Microwave ablation is used to treat certain types of medical conditions, including treating tumors. During microwave ablation treatment, an elongated probe is inserted into the patient's tissue. The probe has a microwave antenna that emits electromagnetic radiation in the microwave spectrum. The electromagnetic radiation heats tumor cells, causing coagulation and destroying the diseased tissue.

[0003] In a microwave ablation system, a generator produces power that is transmitted through the shaft of the probe to a microwave antenna where the energy is transmitted as radiation to surrounding tissue. Some microwave ablation probes use a coaxial cable design in which an inner conductor is separated from a coaxial outer conductor by a dielectric material. U.S. Patent 8,059,059, entitled "Slidable Choke Microwave Antenna," describes a microwave antenna assembly whose radiating portion includes a dipole antenna; the patent is hereby incorporated by reference in its entirety.

[0004] One physical limitation that must be overcome in microwave ablation is the undesirable heating along the coaxial cable caused by reflected power. Therefore, most microwave ablation probes use some type of cooling system to prevent tissue damage along the probe shaft.

[0005] The physical properties of a microwave ablation probe (e.g., probe diameter, material composition, and flexibility) are limited by the technical requirements for propagating energy along the probe shaft. For example, while it is desirable to make the probe diameter as small as possible to be less invasive to patient tissue, shaft heating due to reflected power increases as the probe diameter decreases. Therefore, a trade-off must be made when designing a microwave ablation system.

[0006] Another design consideration is the ability of the microwave ablation probe to penetrate and advance through tissue to the desired ablation location. The probe tip must be sharp enough, and the probe shaft must be rigid enough to allow the microwave antenna to be steered to the correct location. Summary of the invention

[0007] Some examples of the disclosed technology include an introducer kit for a microwave ablation probe having an elongated probe body and a radiating portion configured to emit microwave energy. In some examples, the introducer kit has a cannula having a cannula body that defines an inner cavity that is sized to receive the elongated probe body of the microwave ablation probe. In some examples, the cannula body may have a non-metallic portion positioned along the cannula body so that when the microwave ablation probe is inserted into the cannula, the non-metallic portion overlaps the radiating portion of the microwave ablation probe. In some examples, the introducer kit further includes a tissue penetrating stylet that is sized to be received by the inner cavity of the cannula. Alternatively or in addition, the introducer kit includes a fixing mechanism that is configured to fix the position of at least a portion of the cannula within or to the patient tissue.

[0008] Further examples of the disclosed technology may have one or more alternative or additional features. The fixing mechanism may be, for example: a plurality of sharp teeth, sutures, suction pads, or self-adhesive pads with connectors for anchoring the cannula to tissue. In some examples, the stylet or cannula of the introducer kit has a navigation sensor and / or navigation marker. In some examples, the stylet of the introducer kit has a trocar at the tip of the stylet. In some examples, the cannula is less rigid than the stylet. In some examples, the cannula further has a blunt end. In some examples, the cannula body is made entirely of non-metallic materials. Some examples also include a microwave ablation probe with an elongated probe body having a blunt end.

[0009] Other examples of the disclosed technology include a microwave ablation system including a microwave ablation probe having an elongated probe body and a radiating portion at a distal portion of the probe body for emitting microwave energy. The system includes a cannula having an inner cavity and a window portion at a distal portion of the cannula, the window portion being at least partially transparent to microwave energy. Alternatively or in addition, some examples provide an introducer kit including a cannula and a tissue penetrating stylet sized to be received in the lumen of the cannula.

[0010] Further examples of the disclosed technology may have one or more alternative or additional features. The microwave ablation system may include a fixing mechanism for fixing the position of the cannula within the patient's tissue. In some examples, the window portion of the cannula overlaps with the radiating portion of the microwave ablation probe at the distal portion of the probe body. In some examples, the system also includes a connector that fixes the position of the microwave ablation probe relative to the cannula when the microwave ablation probe is inserted into the inner cavity of the cannula. In some examples, the connector fixes the radiating portion of the microwave ablation probe in a position adjacent to the window portion of the cannula. In some examples, the window portion includes a non-metallic material. In some examples, the non-metallic material is a dielectric polymer.

[0011] Other examples of the disclosed technology include a method of microwave ablation, the method comprising the steps of inserting a microwave ablation probe into the lumen of a cannula; aligning a radiating portion of the microwave ablation probe with a portion of the cannula that is at least partially transparent to microwave energy; and emitting microwave energy from the radiating portion of the microwave ablation probe. Alternatively or in addition, the method includes inserting a tissue piercing stylet into the lumen of the cannula. Alternatively or in addition, the method includes piercing a tissue body with the stylet while inserting the stylet into the lumen of the cannula, and removing the stylet from the lumen of the cannula. Alternatively or in addition, the method includes fixing the cannula at a position within the tissue body, and removing the stylet from the lumen of the cannula while fixing the cannula at a position in the tissue. Alternatively or in addition, the method includes ablating the tissue with microwave energy emitted from the radiating portion of the microwave ablation probe.

[0012] Further examples of the disclosed technology may have one or more alternative or additional features. In some examples, the method includes removing a biopsy sample of tissue through the lumen of the cannula. In some examples, the method includes cooling the microwave ablation probe. In some examples, the method includes securing the microwave ablation probe to the cannula using a connector.

[0013] This summary is an overview of some of the teachings of this application and is not intended to be an exclusive or exhaustive treatment of the subject matter of the present invention. Further details can be found in the detailed description and the appended claims. Other aspects will be clear to those skilled in the art after reading and understanding the following detailed description and viewing the accompanying drawings forming a part thereof, each of which is not intended to be limiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a side view of a microwave ablation system including an introducer assembly and a microwave ablation probe according to some examples.

[0015] Figure 2 is a cross-sectional view of an introducer kit according to some examples.

[0016] Figure 3 is a cross-sectional view of a microwave ablation probe coupled to a cannula of an introducer set.

[0017] Figure 4 yes Figure 1 A cross-sectional view of the cannula taken along line 4-4.

[0018] Figure 5 yes Figure 1 A cross-sectional view of the cannula taken along line 5-5.

[0019] Figure 6 is a side view of an alternative example of a cannula for use with an introducer kit.

[0020] Figure 7 is a side view of a second alternative example of a cannula for an introducer kit.

[0021] Figure 8 is a cross-sectional view of an alternative example of a stylet within a cannula for an introducer kit.

[0022] Fig. 9 is a cross-sectional view of a securing mechanism for an introducer kit according to some examples.

[0023] Fig.10 is inserted into the patient's tissue Figure 1 Cross-sectional view of the introducer kit.

[0024] Fig.11 is fixed in the patient's tissue Figure 1 Cross-sectional view of the cannula.

[0025] Fig.12 It is inserted into the cannula Figure 1 Cross-sectional view of a microwave ablation probe.

[0026] Unless otherwise indicated, the drawings are not drawn to scale. Although the examples herein are susceptible to various modifications and alternative forms, the details have been illustrated by the examples and drawings and will be described in detail. However, it should be understood that the scope of this article is not limited to the specific examples described. On the contrary, it is intended to cover modifications, equivalents, and alternatives that fall within the spirit and scope of this article. DETAILED DESCRIPTION

[0027] The present technology provides an introducer kit for a microwave ablation probe. In some examples, the introducer kit includes a cannula with an inner cavity and a stylet configured to be inserted into the inner cavity. The stylet of the introducer kit has a tissue piercing tip or a tissue penetrating tip that is used to pierce the patient's tissue and guide the introducer kit to the desired ablation location. Once the introducer kit is positioned, the stylet can be removed from the inner cavity of the cannula. The microwave ablation probe is inserted into the inner cavity of the cannula to provide microwave ablation treatment.

[0028] The cannula of the introducer kit is provided with a cannula body, and a portion of the cannula body is transparent to microwave radiation. In some examples, the cannula body includes a window portion made of a material through which microwave energy can pass. In some examples, the cannula body has at least one section made of a material that is transparent to microwave radiation and at least one section made of a material that is opaque to microwave radiation. In some examples, the window portion of the cannula is at least partially made of a non-metallic material. In some examples, the cannula body is partially made of a non-metallic material and partially made of a metallic material. In some examples, the cannula body is made entirely of a non-metallic material.

[0029] During use, a stylet is inserted into the lumen of the cannula. The stylet and cannula of the introducer kit are then inserted into the patient's tissue and guided to the desired ablation location. The introducer kit pierces the patient's tissue, allowing the cannula to advance through the tissue to the ablation location. The stylet has a tissue piercing tip. The microwave transparent window portion of the cannula body is placed adjacent to the tissue to be ablated.

[0030] In some examples, a fixation mechanism is used to fix the cannula in a desired position. The fixation mechanism prevents the cannula from changing its position in the tissue. The stylet is then removed, leaving the cannula in place in the patient's tissue.

[0031] A microwave ablation probe is inserted into the lumen of the cannula. The microwave ablation probe has a radiating portion that emits microwave radiation. The radiating portion of the microwave ablation probe is aligned with a microwave transparent or non-metallic portion of the cannula body. Microwave radiation emitted from the radiating portion travels through the microwave transparent or non-metallic material of the cannula from the inside of the cannula to the outside of the cannula and into the patient's tissue, where the microwave energy heats the patient's tissue and destroys diseased cells. Use of an introducer kit whose cannula has a microwave transparent window allows the microwave ablation probe to be completely contained within the cannula.

[0032] The use of an introducer kit with a tissue-piercing stylet reduces the strength, rigidity, and maneuverability requirements for the microwave ablation probe. In some past systems, the ceramic trocar tip of the microwave ablation probe was used to pierce tissue and maneuver through the tissue to the ablation site, and the microwave ablation probe did not use an introducer kit. In the system described herein, the stylet of the introducer kit will be used to pierce patient tissue and maneuver to the ablation site. As a result, a microwave ablation probe with fewer mechanical requirements, reduced rigidity requirements, reduced maneuverability requirements, and a smaller diameter can be used compared to existing systems. Moreover, the tissue-piercing tip provided on the stylet may be less expensive to manufacture than the ceramic trocar tip provided on past microwave ablation probes, and in some examples, the stylet may be metal.

[0033] Since the introducer kit of the present technology is introduced into the body independently of the microwave ablation probe and does not need to have all the elements of the microwave ablation probe, the introducer kit can be manufactured to have better mechanical strength and reduced manufacturing costs compared to the microwave ablation probes of the past. Moreover, in some examples, the outer diameter of the introducer kit that can accommodate the microwave ablation probe is smaller than the outer diameter of the microwave ablation probe of the past that does not use the introducer kit.

[0034] The metal tissue-piercing tip on the stylet is easier to see on certain imaging systems than the ceramic tip of past microwave ablation probes, facilitating better visualization under ultrasound and fluoroscopy. Enhanced visualization can facilitate placement of multiple probes during ablation of multiple sites.

[0035] The cannula of the introducer kit can be used for many other purposes. A biopsy needle can be inserted into the cannula to collect a tissue sample before an ablation procedure, after an ablation procedure, or both. A drug delivery catheter can be inserted into the cannula to deliver drug therapy before an ablation procedure, after an ablation procedure, or both.

[0036] In some examples, a navigation device is provided, such as a navigation marker or a navigation sensor. An example of a navigation sensor is an electromagnetic navigation sensor. The navigation device can be located in or on the cannula, or the navigation device can be located in or on the stylet. The navigation device is used to ensure that the window portion of the cannula (and therefore the radiating portion of the microwave ablation probe aligned with the window portion) is in the correct ablation position. If the navigation device is provided in the stylet, the position of the stylet is known, and the position of the cannula can be calculated based on the known spatial relationship between the stylet and the cannula. If the navigation system is provided in or on the cannula, the position of the window portion of the cannula can also be determined.

[0037] More than one introducer kit and microwave ablation probe may be used simultaneously to ablate multiple sites. Alternatively, the microwave ablation probe may be repositioned to a different location to apply microwave ablation therapy to the new location. This may be accomplished by removing the probe from the cannula, reinserting the stylet into the cannula, and repositioning the introducer kit to a different location. The stylet may then be removed, and the microwave ablation probe may be reinserted to apply microwave ablation therapy to a different location. This sequence may be repeated for additional treatment locations.

[0038] Introducer Kit for Microwave Ablation Probes

[0039] Figure 1 A side view of a microwave ablation system including an introducer kit and a microwave ablation probe is shown according to some examples. The introducer kit 102 includes a cannula 114 and a stylet 124. The introducer kit 102 is configured for use with a microwave ablation probe 136. Figure 2 is a cross-sectional view of introducer kit 102, and Figure 3 is a cross-sectional view of a microwave ablation probe 136 coupled to the cannula 114 of the introducer set 102 .

[0040] The cannula 114 has a lumen 215 extending through the middle of the cannula 114 from the distal portion 116 to the proximal portion 118 of the cannula 114 (in the Figure 2 and Figure 3 In some examples, the cannula 114 has a blunt tip. The blunt tip is not configured to pierce tissue. In some examples, including Figure 1 In the example of FIG. 1 , the cannula body 115 has a non-metallic portion 141 and a metallic portion 143. Figure 1 In some examples, the non-metallic portion 141 is located near the distal portion 116, and the metallic portion 143 is located near the proximal portion 118. In some examples, the non-metallic portion 141 of the cannula 114 is a window portion 142 that is at least partially transparent to microwave energy; that is, the frequency of radiation emitted in the microwave range of the electromagnetic spectrum is on the order of about 300 megahertz to 300 gigahertz. In some examples, the non-metallic portion 141 is at least partially transparent to microwaves having a frequency of about 915 megahertz, about 2.45 gigahertz, or both. Microwave radiation emitted by a radiation source inside the lumen 215 of the cannula 114 will pass through the transparent non-metallic portion 141 of the cannula 114.

[0041] In some examples, non-metallic portion 141 is resistant to electromagnetic radiation in one or more other regions of the electromagnetic spectrum (e.g., visible light (approximately 4×10 14 Hz to 8×10 14 Hz), X-rays (about 3×10 16Hz to 3×10 19 In some examples, the non-metallic portion is opaque to one or more other regions of the electromagnetic spectrum.

[0042] The stylet 124 has a stylet body 126 having a tissue penetrating stylet tip 131. Figure 1 In the example of the present invention, the stylet 124 has a solid trocar tip. As used herein, the term "trocar" refers to a three-sided cut tip. The outer diameter of the stylet 124 is smaller than the diameter of the lumen 215 of the cannula 114. This allows the stylet 124 to be inserted into the lumen 215, such as Figure 2 As shown. The stylet can be made of metal (eg, stainless steel). In some examples, the cannula 114 is less rigid than the stylet 124. The stiffness of the stylet 124 affects the overall stiffness of the introducer kit 102.

[0043] Microwave ablation probe 136 has an elongated probe body 138 having a proximal end 151 and a distal end 153. A handle 155 and a power coupler 157 are also provided. In some examples, elongated probe body 138 includes a blunt tip that is not configured to penetrate tissue.

[0044] Inside the probe body 138 is a radiating portion 306 that emits microwave energy. In some examples, the radiating portion 306 is a microwave antenna, which can be a helical antenna. The microwave antenna can be a monopole antenna, a dipole antenna, or other configurations. The microwave ablation probe 136 can employ a coaxial antenna. The microwave ablation probe 136 can include a cooling system (not shown) to prevent excessive heating along the length of the probe body 138. The microwave ablation probe 136 can include a choke (not shown) to limit the microwave radiation field. The outer diameter of the elongated probe body 138 is less than the diameter of the inner cavity 215, thereby allowing the microwave ablation probe 136 to be inserted into the inner cavity 215, as shown in FIG. Figure 3 shown.

[0045] Go to Figure 2 , the cannula 114 has a lumen 215 that is sized to receive a stylet body 126 of the stylet 124. The stylet 124 can be slidably inserted into the lumen 215 of the cannula 114 and can also be slidably removed from the lumen 215. In some examples, the cannula stylet connector 281 locks the stylet 124 in place relative to the cannula 114 so that the stylet 124 and the cannula 114 do not separate during insertion into the patient's tissue. When locked together, the stylet tip 131 protrudes from the distal end 218 of the cannula body 115. This allows the stylet tip 131 to pierce and penetrate the patient's tissue.

[0046] Go to Figure 3, the size of the inner cavity 215 is set to receive the elongated probe body 138 of the microwave ablation probe 136. The microwave ablation probe 136 can be slidably inserted into the inner cavity 215 of the cannula 114, and can also be slidably removed from the inner cavity 215. In some examples, when the microwave ablation probe 136 is inserted into the inner cavity 215 of the cannula 114, the cannula ablation probe connector 383 fixes the position of the microwave ablation probe 136 relative to the cannula 114. In this way, the microwave ablation probe 136 will not move relative to the cannula 114 during ablation. In some examples, including Figure 3 In the example of FIG. 3 , when connected using the cannula ablation probe connector 383 , the distal end 153 of the probe body 138 does not protrude from the distal end 218 of the cannula body 115 .

[0047] exist Figure 3 In the example of FIG. 1 , when the probe body 138 is inserted into the cannula 114, the non-metallic portion 141 of the cannula body 115 overlaps with the radiating portion 306 of the microwave ablation probe 136. That is, at least a portion of the electromagnetic radiation emitted from the radiating portion 306 will be incident on the window portion 142 of the cannula body 115. Because the window portion 142 is transparent to the microwave radiation, the radiation will pass through the cannula body 115 unimpeded without being absorbed or reflected by the cannula body 115.

[0048] The length of the window portion 142 of the cannula body 115 is based on the specific antenna used in the microwave ablation probe 136. In some examples, the length is at least about 7 mm, at least about 10 mm, or at least about 13 mm. In some examples, the length is at most about 30 mm, or at most about 20 mm. In one example, the length is about 15 mm. A longer radiating portion 306 requires a longer length of the cannula body 115 to be transparent, thereby requiring a longer window portion 142. A shorter length radiating portion can accommodate a shorter length of the window portion 142. The window portion 142 is positioned along the length of the cannula body 115 so that when the radiating portion 306 emits microwave energy, at least a portion of the microwave energy will encounter and pass through the window portion 142 so that surrounding tissue can be ablated.

[0049] In some examples, the outer diameter of the cannula is at least about 16 gauge (1.29 mm), at least about 15 gauge (1.45 mm), or at least about 14 gauge (1.63 mm). In some examples, the outer diameter of the cannula is at most about 12 gauge (2.05 mm), or at most about 13 gauge (1.83 mm). In some examples, Figure 4The inner diameter D of the cannula shown is at least about 18 gauge (1.02 mm), at least about 17 gauge (1.15 mm), or at least about 16 gauge (1.29 mm). In some examples, the inner diameter D of the cannula is at most about 13 gauge (1.83 mm), or at most about 14 gauge (1.63 mm).

[0050] The size of the microwave ablation probe and the stylet is set to fit easily in the lumen of the cannula and slide in the lumen. The outer diameter of the microwave ablation probe and the outer diameter of the stylet are smaller than the inner diameter of the cannula. In some examples, the outer diameter of the microwave ablation probe is at least about 18 (1.02 mm), at least about 17 (1.15 mm), or at least about 16 (1.29 mm). In some examples, the outer diameter of the microwave ablation probe is at most about 12 (2.01 mm), at most about 13 (1.83 mm), or at most about 14 (1.63 mm). In some examples, the outer diameter of the stylet is at least about 18 (1.02 mm), at least about 17 (1.15 mm), or at least about 16 (1.29 mm). In some examples, the outer diameter of the stylet is at most about 12 (2.01 mm), at most about 13 (1.83 mm), or at most about 14 (1.63 mm).

[0051] Cannula, stylet and microwave ablation probe can be set to various lengths and are elongated in shape. The length of each of these components is much greater than its diameter. For example, the length can be 10 times or more of the diameter, 50 times or more of the diameter, 100 times or more of the diameter, or 200 times or more of the diameter. In some examples, the length can be at least 5 cm or at least 10 cm.

[0052] Locking mechanism between cannula and stylet or microwave ablation probe

[0053] Some implementations of the disclosed technology may include a cannula stylet connector 281 and a cannula ablation probe connector 383. In some examples, the cannula 114 includes a cannula connector 185 configured to lock the cannula 114 in place relative to the stylet 124 or the microwave ablation probe 136 or both. The stylet connector 187 of the stylet 124 interfaces with the cannula connector 185 to lock the cannula body 115 in place relative to the stylet body 126. In some examples, such as Figure 2 For example, when the cannula connector 185 and the stylet connector 187 are locked together, the spatial relationship between the cannula body 115 and the stylet body 126 is fixed so that the stylet tip 131 protrudes from the distal end 218 of the cannula body 115. The cannula stylet connector 281 may include, for example, a Luer lock fitting or other similar mechanism.

[0054] exist Figure 3 In the example of the microwave ablation probe 136, the probe connector 189 is configured to lock the probe body 138 in a proper position relative to the cannula body 115. The probe connector 189 is connected to the cannula connector 185 to lock the probe body 138 in a proper position relative to the cannula body 115. In some examples, such as Figure 3 In an example, when the cannula connector 185 and the probe connector 189 are locked together, the spatial relationship between the probe body 138 and the cannula body 115 is fixed so that the radiating portion 306 of the microwave ablation probe 136 does not protrude from the distal end 218 of the cannula body 115. The cannula ablation probe connector 383 may include, for example, a Luer lock fitting or other similar mechanism.

[0055] It should be appreciated that cannula stylet connector 281 and cannula ablation probe connector 383 may be implemented in a variety of different ways and that the specific examples provided herein are not intended to be limiting.

[0056] Materials used for cannulae

[0057] Figure 4 The non-metallic portion 141 of the cannula body 115 is shown along Figure 1 4-4 of the cross section. The non-metallic portion 141 of the cannula body 115 has an outer surface 435. The inner cavity 215 has an inner surface 437 that defines an inner cavity diameter D. In some examples, the non-metallic portion 141 is made of a non-metallic material throughout the thickness T of the cannula wall 402 from the inner surface 437 to the outer surface 435. The non-metallic portion 141 is transparent to microwave radiation. In some examples, the non-metallic material is a dielectric polymer. In some examples, the non-metallic portion 141 is made of a braided material. The non-metallic portion 141 of the cannula body 115 can be a reinforced polymer tube, such as a polyimide tube with an embedded braid or coil (e.g., an embedded polymer braid or coil).

[0058] In some examples, the probe is less rigid than the cannula. In some examples, the bending modulus of the probe is less than or equal to the bending modulus of the cannula. This relationship helps the cannula guide the probe to the ablation position when the probe is inserted into the cannula, and the probe does not cause the position of the cannula to shift. In other examples, the cannula is less rigid than the probe.

[0059] Examples of materials for the polymer tube of the non-metallic portion of the cannula body 115 include fluoropolymers, urethane, polyether block amide (PEBA), polypropylene, polyethylene, polyamide (nylon), polyimide, polyetherimide (PEI), polysulfone, and polyetheretherketone (PEEK). Examples of materials for polymer fiber braids or coils include polyamides, polyesters, and aramids. Alternatively, the non-metallic portion 141 may be a ceramic material.

[0060] Other choices of materials for the embedded braid or coil include aromatic polyester fibers, para-aramid synthetic fibers, carbon fibers, fibers spun from liquid crystal polymers, polyparaphenylene terephthalamide fibers, VECTRAN TM Material fiber (available from Kuraray Co., Ltd., which has a business office in Kurashiki, Okayama, Japan), and KEVLAR TM Material Fiber (available from DowDuPont Inc., having a place of business in Wilmington, Delaware). VECTRAN TM Materials The liquid crystal polymer braid is transparent to microwave energy and has a high dielectric strength. In some examples, the non-metallic portion 141 is resilient at high temperatures, for example having a melting temperature greater than 150 degrees Celsius.

[0061] Figure 5 The metal portion 143 of the cannula body 115 is shown along Figure 1 5-5 of the cross section. The metal portion 143 of the cannula body 115 has an outer surface 535. Along this portion of the body, the lumen 215 has an inner surface 537. In some examples, the metal portion 143 is made of a metal material throughout the thickness of the cannula wall 502 from the inner surface 537 to the outer surface 535. In some examples, the metal portion 143 of the cannula body 115 may include stainless steel. In some examples, the metal-containing region may include nitinol or a polymer tubing with an embedded metal braid (e.g., stainless steel or tungsten braid).

[0062] Alternative Intubation Examples

[0063] Figure 6 and Figure 7 An alternative example of a cannula for an introducer kit for a microwave ablation probe is shown. Figure 6 In the example of FIG. 6 , the cannula 614 has a cannula body 615 having a first metal portion 648 at a proximal end 618, a second metal portion 644 at a distal end 616 of the cannula body 615, and a non-metal portion 642 extending between the first metal portion 648 and the second metal portion 644. Figure 1Like cannula 114, cannula 614 has an inner lumen (at Figure 6 The length L of the non-metallic portion 642 will be determined based on the specific antenna used in the microwave ablation probe.

[0064] The non-metallic portion 642 is made of non-metallic material throughout the thickness of the cannula wall from the inner surface of the lumen to the outer surface of the cannula body 615. The first metal portion 648 and the second metal portion 644 can be made of metallic material throughout the thickness of the cannula wall from the inner surface of the lumen to the outer surface of the cannula body 615.

[0065] exist Figure 7 In the example of FIG. 7 , the cannula 714 has a cannula body 715 that substantially includes a non-metallic portion 742. In this example, the cannula body 715 does not include a metal portion. Figure 1 Like cannula 114, cannula 714 has an inner lumen (at Figure 7 The non-metallic portion 742 is made of non-metallic material over the entire thickness of the cannula wall from the inner surface of the lumen to the outer surface of the cannula body 715.

[0066] A navigation device 745 is disposed within the lumen of the cannula 714, at the distal end. As will be described in greater detail below, the navigation device 745 is used to locate and / or track the position of the cannula 114 within the patient's tissue.

[0067] Examples of Alternative Stylets for Introducer Kits

[0068] Figure 8 An alternative example of a stylet for an introducer kit for a microwave ablation probe is shown. Figure 1 and Figure 2 In the example of , the stylet 124 is a solid piece. Figure 8 In the example of the embodiment of the present invention, the stylet 824 has a stylet body 826 having a lumen 814 extending through the stylet body 826. The stylet 824 has a tissue piercing tip 852. The stylet tip 852 can be a trocar. A navigation device 845 is disposed within the lumen 814 of the stylet 824. As will be described in more detail below, the navigation device 845 is used to locate and / or track the position of the cannula 114 within the patient's tissue.

[0069] Navigation devices and systems

[0070] Some examples of the disclosed technology provide a navigation device for use with a navigation system to locate the position of the introducer kit 102, the microwave ablation probe 136, or both within the patient's body. The navigation device can be provided on at least one navigation marker or at least one navigation sensor on one or more of the cannula of the introducer kit, the stylet of the introducer kit, and the microwave ablation probe 136.

[0071] As the term is used herein, a "navigation marker" can be a physical feature of an introducer kit that can be seen, for example, using fluoroscopy, ultrasound imaging, computed tomography (CT) imaging, or other medical imaging techniques. The navigation marker can be made of a material (e.g., metal) that can be seen under one or more medical imaging techniques.

[0072] As the term is used herein, a navigation sensor is similar to a navigation marker in that the navigation sensor is also visible using one or more medical imaging techniques. In addition, the navigation sensor is capable of communicating information about the body tissue in which it is located to an external device that is part of a navigation system. The navigation sensor can be, for example, an electromagnetic navigation sensor. Electromagnetic navigation systems are used to locate the position of a medical tool within a patient's body by using magnetic fields, electric fields, or both. Data, such as impedance and potential measurements, can be transmitted from the electromagnetic navigation sensor within the body to an external receiver. In some examples, the electromagnetic navigation sensor reduces or eliminates the need to perform fluoroscopy to locate the medical tool within the patient's body. Examples of electromagnetic navigation systems and tools include the RHYTHMIA HDx TM Mapping system, INTELLANAV TM ABLATION CATHETER AND INTELLAMAPORION TM Mapping catheter (available from Boston Scientific Corporation Inc., with offices in Natick, Mass.) Another example of a navigation system is the superDimension TM Navigation system (available from Medtronic, Inc., having offices in Minneapolis, Minnesota). Other examples of navigation systems and devices are the SPiN Thoracic Navigation system TM and Always-On TipTracked TM Device (available from Veran Medical Technologies, having offices in St. Louis, Missouri).

[0073] Reference now Figure 2 and Figure 3In some examples of the disclosed technology, the cannula 114 includes at least one navigation device 237. The navigation device 237 can be located at the distal end 218 of the cannula 114. In some examples, the navigation device 237 is located at the farthest end or distal tip of the cannula 114. In alternative examples, the navigation device 237 can be located at a different portion of the cannula 114.

[0074] In some examples of the disclosed technology, Figures 1 to 3 The stylet 124 includes at least one navigation device (not shown). In some examples, the stylet body 126 has an echogenic feature that can be seen during ultrasound imaging. In other examples, the stylet body 126 does not include a navigation device.

[0075] exist Figure 7 In the example of a cannula having a cannula body non-metallic portion 742, the cannula 714 may include at least one navigation device 745, which may be a navigation marker or a navigation sensor. The cannula 714 may be used with a stylet having a navigation device, or may be used with a stylet without a navigation device. The cannula 714 may be used with a microwave ablation probe having a navigation device, or may be used with a microwave ablation probe without a navigation device.

[0076] exist Figure 8 In the example of an introducer kit having a stylet 824 defining an inner lumen 814, a navigation device 845 is disposed inside the inner lumen 814 of the stylet 824 and is positioned near the distal end of the stylet 824. The navigation device 845 can be a navigation marker or a navigation sensor. The stylet 824 having the navigation device 845 can be used with a cannula that also includes the navigation device, or can be used with a cannula that does not include the navigation device.

[0077] In various examples, the microwave ablation probe can include a navigation device, such as a navigation marker or a navigation sensor.

[0078] Fixed mechanism

[0079] In some examples of the disclosed technology, a fixing mechanism is provided for fixing the position of the introducer kit and the microwave ablation probe relative to the patient tissue. When the fixing mechanism is used, the cannula 114 is fixed in an appropriate position relative to the patient tissue so that when the stylet 124 or the microwave ablation probe 136 is inserted into or removed from the lumen of the cannula 114, the cannula 114 does not move relative to the patient tissue. Fixing the cannula 114 in an appropriate position relative to the patient tissue prevents the cannula 114 from changing its position in the body. This ensures that the cannula 114 is in a desired position relative to the tissue to be ablated. In some examples, after the cannula has been turned to the desired position and fixed in the patient tissue, the fixing mechanism itself does not move relative to the patient tissue.

[0080] Fig. 9 9 is a cross-sectional view of a securing mechanism 901 for an introducer kit according to some examples. A self-adhesive pad 912 includes an adhesive layer 914 configured to adhere to the patient's skin. An adapter 931 is connected to the self-adhesive pad 912. The adapter 931 is configured to provide a passage for the introducer kit 102 and the microwave ablation probe 136 to enter the patient's body. Fig. 9 In the example of the embodiment of the present invention, the adapter 931 is a Tuohy Borst adapter. The adapter 931 has an adapter body 921 and a threaded cap 941. A central channel 945 is provided for the introducer kit 102 to enter the patient's body. The locking grommet allows the introducer kit 102 to be locked in place relative to the fixing mechanism 901. During use, the introducer kit 102 is inserted into the central channel 945. The cannula 114 is then locked in place relative to the fixing mechanism 901. This fixes the position of the cannula 114 at the location to be ablated in the patient's tissue.

[0081] Steering Fig.10 and Fig.11 In an alternative example of a fixation mechanism, the cannula 114 has a plurality of tines 1071. Each of the tines has a distal tip 1051 that can penetrate patient tissue. The tines 1071 can be advanced through the penetrated tissue. In some examples, the tines 1071 can extend through the cannula body 115. When the introducer kit 102 is inserted into the patient tissue 1001 and the tissue 1003 to be ablated (e.g., a tumor), the tines are first retracted, such as Fig.10 When the introducer assembly 102 reaches the desired ablation location, the tines 1071 are deployed, as shown in FIG. Fig.11The deployed tines pierce the patient tissue and travel through the patient tissue. The deployed tines secure the position of the cannula 114 at the location to be ablated in the patient tissue. In some examples, the deployed tines secure the position of the cannula 114 by bending outwardly and upwardly against the insertion direction of the cannula 114. In some examples, the tines are present and can be deployed at multiple locations along the length of the shaft of the cannula.

[0082] Alternative fixation mechanisms are contemplated. For example, a suture attachment may be used to secure the position of the outer portion of the cannula 114 to the patient's skin so that the tip of the cannula remains at the location to be ablated within the patient's tissue. Alternatively, a suction pad device may be secured to the outer portion of the cannula 114 to the patient's skin using negative pressure to provide fixation of the cannula tip relative to the location to be ablated. Other fixation mechanisms are also possible and are within the scope of the current claims.

[0083] Method for using an introducer kit with a microwave ablation probe

[0084] A method for guiding a microwave ablation probe and performing ablation using the microwave ablation probe is provided. Fig.10 is inserted into the patient's tissue Figure 1 sectional view of an introducer kit of . The method includes inserting a tissue piercing stylet 124 into the lumen 215 of a cannula 114 to form an introducer kit 102. The method further includes piercing a body of tissue 1001 with a stylet tip 131 when inserting the stylet 124 into the lumen 215 of the cannula 114. The introducer kit 102 is moved through the patient tissue 1001 until the cannula 114 is located at a tissue portion 1003 (e.g., a tumor) to be ablated. In some examples, a transparent window portion 142 is located at the location of the tissue to be ablated. In some examples, the cannula 114 is fixed at this location in the tissue 1001. In alternative examples, it is possible that the cannula 114 is not fixed at this location in the tissue 1001.

[0085] In some examples, a navigation system is employed when the introducer assembly 102 is advanced through the patient's tissue and / or when the cannula 114 is located at the location of the tissue to be ablated. The navigation system may include navigation devices such as navigation markers or navigation sensors, field or radiation sources, and detectors of electric fields, magnetic fields, electromagnetic radiation, or similar systems.

[0086] As an example, a navigation device 237 on the cannula 114 can be used. When the cannula 114 is inside the patient's tissue, one or more imaging scans are performed on the cannula 114 and the tissue 1003 to be ablated. When the medical imaging scan is performed, the navigation device 237 of the cannula 114 is present at the location of the tissue 1003 to be ablated in the patient's tissue 1001. The navigation device 237 allows the physician to know whether the window portion 142 of the cannula 114 is located at the correct ablation location. The navigation system can also provide information about whether the tissue 1003 to be ablated is close to a blood vessel, an internal organ, or other anatomical features.

[0087] As an alternative example, a navigation device such as a navigation marker or a navigation sensor can be provided on the stylet 124. The navigation device in or on the stylet 124 (e.g., at the tip of the stylet) is used to determine the position of the stylet 124. In some examples, the stylet 124 and the cannula 114 can be locked together so that the stylet 124 and the cannula 114 do not move relative to each other during the process of positioning the introducer kit 102 within the tissue. Therefore, based on the determined position of the stylet 124, the position of the non-metallic window portion 142 of the cannula 114 can be calculated.

[0088] If a navigation device is present in the cannula 114, such as Figure 7 In the example of FIG. 7 , the navigation device 745 may be employed before or after the stylet 124 is removed from the cannula 114 .

[0089] In some examples, before or after stylet 124 is removed from cannula 114 , a fixation mechanism is deployed to fix the position of cannula 114 relative to patient tissue 1001 and tissue to be ablated 1003 .

[0090] After the introducer kit 102 is inserted into the patient's tissue and guided to the location of the tissue to be ablated, the stylet 124 is removed from the cannula lumen 215 . Fig.11 yes Figure 1 14, wherein the stylet 124 is no longer present within the lumen 215 of the cannula 114.

[0091] After the stylet 124 is removed from the cannula 114 , the probe body 138 of the microwave ablation probe 136 is inserted into the lumen 215 of the cannula 114 . Fig.12 is a cross-sectional view of microwave ablation probe 136 inserted into cannula 114. In some examples, microwave ablation probe 136 is inserted into lumen 215 while cannula 114 is secured in position in tissue using a securing mechanism. Probe body 138 is inserted into lumen 215 and travels through lumen 215 of cannula body 115.

[0092] The radiating portion 306 of the microwave ablation probe 136 is aligned with the window portion 142 of the cannula 114, which is at least partially transparent to microwave energy. In some examples, the window portion 142 of the cannula is at least partially made of non-metallic material 141. In some examples, the radiating portion 306 of the microwave ablation probe 136 is moved into the lumen 215 of the cannula 114 so that the radiating portion 306 is near the distal end 218 of the cannula 114.

[0093] In some examples, the cannula 114 and the microwave ablation probe 136 are locked together using a cannula ablation probe connector 383. The cannula ablation probe connector 383 may include a cannula connector 185 and a probe connector 189. In this case, the position of the cannula body 115 is fixed relative to the probe body 138. In examples where a navigation system has been used to determine the position of the cannula 114 in the patient's tissue, the position of the window portion 142 of the cannula 114 relative to the tissue 1003 to be ablated is known. The position of the radiating portion 306 of the microwave ablation probe 136 relative to the window portion 142 of the cannula 114 is known. Therefore, the position of the radiating portion 306 relative to the tissue 1003 to be ablated can be calculated.

[0094] exist Fig.12 In the example of , the microwave ablation probe 136 is operably connected to the power generator 1201. The power generator 1201 provides power to the microwave ablation probe 136. When power is transmitted to the radiating portion 306 of the microwave ablation probe 136, microwave energy in the form of microwave radiation is emitted from the radiating portion 306 inside the inner cavity 215. The microwaves travel through the transparent window portion 142, then exit the cannula body 115 and enter the tissue 1003 to be ablated, so that the tissue 1003 is heated and tissue coagulation is caused, thereby killing the ablated cells. Fig.12 In the example of FIG. 1 , when ablating the surrounding tissue 1003 , the non-metallic portion 141 overlaps with the radiating portion 306 of the microwave ablation probe 136 .

[0095] exist Fig.12 In some examples, microwave ablation probe 136 and cannula 114 are locked together by cannula ablation probe connector 383. In some examples, after ablation of tissue 1003 to be ablated, microwave ablation probe 136 and cannula 114 are simultaneously withdrawn from patient tissue in a locked configuration. In some examples, ablation can be performed during removal of microwave ablation probe 136 and cannula 114. This can prevent needle tract seeding, in which malignant cells are dragged through the zone created by cannula 114 when cannula 114 is removed from patient tissue.

[0096] In some examples, a biopsy sample of tissue to be ablated can be removed through the cannula lumen 215 before ablation, after ablation, or both. In some examples, a drug delivery catheter can be inserted into the cannula to deliver drug therapy before the ablation procedure, after the ablation procedure, or both.

[0097] After ablating the first location, the microwave ablation probe can be repositioned to a different second location to apply microwave ablation therapy during the procedure. This can be done by removing the probe from the cannula, reinserting the stylet into the cannula, and repositioning the introducer kit to the second location. The stylet can then be removed, and the microwave ablation probe can be reinserted, and microwave ablation therapy applied to the second location. This sequence can be repeated for additional treatment locations.

[0098] Alternatively, multiple introducer sets and microwave ablation probes may be inserted into the patient's tissue to provide ablation from multiple sources during the procedure.

[0099] Using navigation devices in the introducer assembly, microwave ablation probes, or both, and using an external navigation system, imaging assistance and computational assistance can be provided to map the positions of multiple ablation probes and calculate appropriate power settings based on the tumor or other tissue to be ablated.

[0100] It should be noted that, as used in this specification and the appended claims, the singular forms include pluralities unless the context clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0101] All publications and patent applications cited in this specification are herein incorporated by reference in their entirety.

[0102] The disclosed technology has been described with reference to various examples and techniques. However, it should be understood that many changes and modifications can be made without departing from the spirit and scope of the disclosed technology.

Claims

1. A microwave ablation system, comprising: a microwave ablation probe having an elongated probe body and a radiation portion at a distal portion of the probe body for emitting microwave energy; as well as A cannula having: a cannula body comprising a first material that is opaque to microwave energy; an inner cavity sized to receive the elongated probe body of the microwave ablation probe, and a window portion at a distal portion of the cannula body, the window portion comprising a second material that is at least partially transparent to microwave energy; The microwave ablation probe is configured to be completely accommodated in the cannula, so that the window portion of the cannula body overlaps with the radiation portion of the microwave ablation probe, and microwave energy is radiated through the window portion of the cannula body.

2. The microwave ablation system of claim 1, further comprising an introducer kit comprising the cannula and a tissue-penetrating stylet, the tissue-penetrating stylet being sized to be received within the lumen of the cannula.

3. The microwave ablation system according to any one of claims 1 to 2, further comprising a fixing mechanism for fixing the position of the cannula in the patient's tissue. 4 . The microwave ablation system according to claim 1 , further comprising a connector configured to fix a position of the microwave ablation probe relative to the cannula when the microwave ablation probe is inserted into the inner cavity of the cannula. 5 .

5. The microwave ablation system according to claim 4, wherein: The connector fixes the radiation portion of the microwave ablation probe at a position adjacent to the window portion of the cannula.

6. The microwave ablation system according to any one of claims 1 to 5, wherein: The window portion includes a non-metallic material.

7. The microwave ablation system according to claim 6, wherein: The non-metallic material is a dielectric polymer.

8. The microwave ablation system according to any one of claims 1 to 7, wherein: The cannula body includes a non-metallic portion positioned along the cannula body such that when the microwave ablation probe is inserted into the cannula, the non-metallic portion overlaps a radiating portion of the microwave ablation probe; as well as The system further comprises a stylet, the size of which is configured to be received by the lumen of the cannula.

9. The microwave ablation system according to claim 8, wherein: The stylet or the cannula further includes at least one of a navigation sensor and a navigation marker.

10. The microwave ablation system according to any one of claims 8 to 9, wherein: The stylet further includes a tissue penetrating tip.

11. The microwave ablation system according to any one of claims 1 to 10, wherein: The cannula body is made entirely of non-metallic materials.

12. The microwave ablation system of any one of claims 1-11, wherein the elongated probe body comprises a blunt tip.

13. The microwave ablation system according to any one of claims 1 to 12, further comprising a fixing mechanism, the fixing mechanism being configured to fix the position of at least a portion of the cannula in or to the patient tissue, the fixing mechanism being one of the following: a plurality of tines for anchoring the cannula to tissue; Sutures; Suction pads; and Includes self-adhesive pads for connectors.

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