Patent Application
20230063557
The present disclosure is directed to cryogenic devices, and, more specifically, to cryogenic probes having a flexible shaft connected to an ablation tip, and related methods.
The present disclosure contemplates that cryogenic devices, such as cryogenic probes, may be used in various medical and surgical procedures. Generally, cryogenic probes may be used to apply extremely cold temperatures to a target tissue. Cryogenic probes may be used for cryoablation and/or cryoanalgesia, for example.
The present disclosure contemplates that some cryogenic probes may be supplied with one or more cryogenic fluids, which may be used to cool a tissue-contacting portion, such as an ablation tip. Some cryogenic probes may include supply conduits, which convey cryogenic fluid to the ablation tip, and exhaust conduits, which convey used cryogenic fluid away from the ablation tip. Some cryogenic probes may utilize cryogenic fluids supplied at high pressures. For example, some cryogenic probes employing Joule-Thompson expansion in the ablation tip may receive liquid nitrous oxide at up to about 1200 psi and about room temperature and/or may exhaust the nitrous oxide as a gas or mixed phase of gas and liquid at about 45 psi and about −90° F. The cryogenic probe and associated conduits and connectors may be designed to withstand such pressures and temperatures.
The following patent references may provide context for the present disclosure and are incorporated by reference herein in their entireties: U.S. Pat. No. 8,915,908, U.S. Patent Application Publication No. 2020/0022745, and U.S. Patent Application Publication No. 2020/0085485.
The present disclosure contemplates that while cryogenic probes may utilize extremely cold temperatures to achieve desired effects at desired locations, exposure of other locations to extremely cold temperatures may cause undesired effects. For example, it may be desirable for the ablation tip of a cryogenic probes to be extremely cold while the shaft on which the tip is disposed remains above a tissue-ablating temperature. The present disclosure provides methods and apparatus that improve the ability of cryogenic probes to cool an ablation tip to a desired temperature while maintaining other portions of the cryogenic probes at warmer temperatures to reduce the likelihood of freezing non-target tissues.
While known cryogenic devices have been used safely and effectively to perform cryosurgical procedures, improvements in the construction and operation of cryogenic probes may be beneficial for users (e.g., surgeons) and patients. The present disclosure includes various improvements which may enhance the construction, operation, and methods of use of cryogenic probes.
It is an aspect of the present disclosure to provide a cryogenic probe including a distal ablation tip and/or an elongated, generally tubular shaft extending proximally from the ablation tip. The shaft may include a flexible thermoplastic body, a supply conduit extending through the body, the supply conduit being configured to convey cryogenic fluid distally to the ablation tip, and/or an exhaust conduit extending through the body, the exhaust conduit being configured to convey spent cryogenic fluid proximally from the ablation tip. The supply conduit and/or the exhaust conduit may be embedded within the body.
In a detailed embodiment, the exhaust conduit may be disposed generally centrally within the body. The supply conduit may be generally helically shaped. The generally helically shaped supply conduit may be disposed radially around the generally centrally disposed exhaust conduit. The exhaust conduit may be generally concentrically disposed within the supply conduit. The supply conduit may be generally concentrically disposed within the body.
In a detailed embodiment, the supply conduit may be embedded in the body and/or the exhaust conduit may be embedded in the body. The supply conduit and the exhaust conduit may be disposed in the body in a generally parallel and spaced apart arrangement.
In a detailed embodiment, the shaft may include at least one auxiliary lumen extending generally longitudinally through the body.
In a detailed embodiment, at least one of the supply conduit and the exhaust conduit may include a reinforcing structure. The reinforcing structure may include a generally tubular braid reinforcement. The braid reinforcement may be constructed from at least one of stainless steel, nylon, high density polyethylene, polyethylene terephthalate, carbon fibers, and/or poly para-aramid.
It is an aspect of the present disclosure to provide a cryogenic surgical system including a cryogenic probe as described above and/or a cryogenic module configured to be operatively coupled to the cryogenic probe to supply cryogenic fluid to the cryogenic probe.
It is an aspect of the present disclosure to provide a method of making a cryogenic probe including providing an elongated, generally tubular shaft. The shaft may include a flexible thermoplastic body, a supply conduit extending through the body, the supply conduit being configured to convey cryogenic fluid, and/or an exhaust conduit extending through the body, the exhaust conduit being configured to convey spent cryogenic fluid. The supply conduit and/or the exhaust conduit may be embedded within the body. The method may include attaching an ablation tip distally on the shaft so that an internal cavity of the ablation tip fluidically interposes the supply conduit and the exhaust conduit.
In a detailed embodiment, the method may include attaching a handle proximally on the shaft. Providing the elongated, generally tubular shaft may include extruding the body. Extruding the body may include embedding the supply conduit and/or the exhaust conduit therein. Extruding the body may include forming at least one auxiliary lumen extending generally longitudinally through the body.
In a detailed embodiment, the exhaust conduit may be disposed generally centrally within the body. The supply conduit may be generally helically shaped. The generally helically shaped supply conduit may be disposed radially around the generally centrally disposed exhaust conduit. The exhaust conduit may be generally concentrically disposed within the supply conduit.
In a detailed embodiment, the supply conduit and the exhaust conduit may be disposed in the body in a generally parallel and spaced apart arrangement.
In a detailed embodiment, the supply conduit and/or the exhaust conduit may include a reinforcing structure. The reinforcing structure may include a generally tubular braid reinforcement.
Example embodiments are described in conjunction with the accompanying drawing figures in which:
Example embodiments according to the present disclosure are described and illustrated below to encompass devices, methods, and techniques relating to cryogenic devices, such as a cryogenic probe having a flexible shaft connected to an ablation tip, and related methods. Of course, it will be apparent to those of ordinary skill in the art that the embodiments discussed below are examples and may be reconfigured without departing from the scope and spirit of the present disclosure. It is also to be understood that variations of the example embodiments contemplated by one of ordinary skill in the art shall concurrently comprise part of the instant disclosure. However, for clarity and precision, the example embodiments as discussed below may include optional steps, methods, and features that one of ordinary skill should recognize as not being a requisite to fall within the scope of the present disclosure. Unless explicitly stated otherwise, any feature or function described in connection with any example embodiment may apply to other example embodiments, and repeated description of similar features and functions is omitted for brevity.
For clarity, the following description references a distal direction 14 and a proximal direction 16. The proximal direction 16 may be generally opposite the distal direction 14. As used herein, “distal” may refer to a direction generally away from an operator of a system or device (e.g., a surgeon), such as toward the distant-most end of a device that is inserted into a patient's body. As used herein, “proximal” may refer to a direction generally toward an operator of a system or device (e.g., a surgeon), such as away from the distant-most end of a device that is inserted into a patient's body. It is to be understood, however, that example directions referenced herein are merely for purposes of explanation and clarity, and should not be considered limiting.
Referring to
In some example embodiments, the shaft 108 may include a first, proximal portion 112 and/or a second, distal portion 114. In some example embodiments, the proximal portion 112 of the shaft 108 may be generally rigid and/or generally elastically deformable. For example, the proximal portion 112 of the embodiment illustrated in
Referring to
In some example embodiments, the ablation tip 110 may include a wall 122 at least partially defining an internal cavity 124. The wall 122 may at least partially define a generally rounded shape, or any other shape as desired for engagement with a target anatomy. The ablation tip 110 may include a nozzle 126 (e.g., an orifice) through which cryogenic fluid from the supply conduit 118 enters the internal cavity 124. The internal cavity 124 may be fluidically coupled to the exhaust conduit 120. Thus, the internal cavity 124 of the ablation tip 110 may fluidically interpose the supply conduit 118 and the exhaust conduit 124.
In operation, cryogenic fluid supplied from the cryogenic module 12 (
In the example embodiment illustrated in
Referring to
In some alternative example embodiments, one or more of the conduits 202, 204 may be arranged in a generally spiral (e.g., helical) configuration.
Referring to
In some example embodiments, the shaft 200 may include a body 210 at least partially containing the conduits 202, 204. For example, the shaft 200 may include a body 210 having a generally circular cross section disposed around the conduits 202, 204. In some example embodiments, the body 210 may be formed from extruded thermoplastic. In the example embodiment illustrated in
The body 210 may be partially or completely substantially solid and/or may include one or more voids and/or lumens in addition to the one or more conduits 202, 204. For example, the body 210 may include one or more auxiliary lumens 212. For example, one or more auxiliary lumens 212 may extend longitudinally the entire length of the shaft 200 and/or one or more auxiliary lumens 212 may extend only partway through the length of the shaft 200.
In some example embodiments, an auxiliary lumen 212 may be used to route a component or instrument generally between a proximal portion of the shaft 200 and a distal portion of the shaft 200. For example, thermocouple wires may be routed through the auxiliary lumen 212. In some example embodiments, one or more auxiliary lumens 212 may be used to convey a fluid (e.g., a fluid other than the cryogenic fluid) longitudinally along the shaft 200. For example, a warming fluid (e.g., air, water, saline, etc.) may be conveyed from a proximal portion of the shaft 200 to a distal portion of the shaft 200. Some example embodiments may include one or more additional auxiliary lumens, which may act as a return pathway for such warming fluids. In some example embodiments, one or more auxiliary lumens 212 or voids may act as insulation, such as between one or more of the conduits 202, 204 and tissues adjacent to the shaft 200.
In the example embodiment illustrated in
In some example embodiments, materials for various components of the shaft may be selected or configured to provide desired insulation and/or flexibility characteristics. For example, materials, such as thermoplastics, may be used to form various components of the shaft 200. Some example embodiments may include laser cuts (e.g., to increase flexibility) and/or wire braid reinforcements (e.g., to increase strength).
Some example embodiments according to at least some aspects of the present disclosure may be fabricated by one or more extrusion processes. For example, the thermoplastic body 210 may be extruded around previously formed braid reinforcements 206, 208. In some example embodiments, additional lumens or voids (e.g., auxiliary lumen 212) may be formed as the body 210 is extruded. In some example embodiments, the resulting shaft may comprise a single-piece structure including a one or more embedded conduits and/or lumens, one or more of which may be reinforced. In other words, some example embodiments may comprise a multi-lumen shaft including a single tube extruded with multiple conduits/lumens embedded therein.
Some example embodiments according to at least some aspects of the present disclosure may include shaft elements that provide improved usability relative to other cryogenic probes, such as cryogenic probes utilizing relatively bulky external insulative materials. For example, some example embodiments may be generally more flexible and/or smaller in diameter than other cryogenic probes, which may improve use in connection with robotic instrumentation and/or which may facilitate improved access to difficult anatomy, such as during open surgical procedures.
Following from the above description and invention summaries, it should be apparent to those of ordinary skill in the art that, while the methods and apparatuses herein described constitute example embodiments according to the present disclosure, it is to be understood that the scope of the disclosure contained herein is not limited to the above precise embodiments and that changes may be made without departing from the scope as defined by the following claims. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects disclosed herein in order to fall within the scope of the claims, since inherent and/or unforeseen advantages may exist even though they may not have been explicitly discussed herein.
