Patent Description:
Various catheters are used within different body lumens for different applications, including to deliver fluids, as a diagnostic or treatment option, to the body lumen. The fluid may be a liquid, a gas, or a mixture of both a liquid and a gas. The delivery may involve spraying the fluid on the wall of the body lumen. In some cases, the efficacy and/or efficiency of the procedure may be dependent on how close to or far away from the body lumen the fluid is delivered from the catheter. For purposes of delivering a catheter through an endoscope within a body lumen, the profile of the catheter has a certain diameter. When extended outside of the scope that profile may result in the catheter being less than an optimum distance from the lumen wall for efficient delivery of the fluid.

As an example, cryosurgery is a procedure in which diseased, damaged or otherwise undesirable tissue (collectively referred to herein as "target tissue") is treated by focal delivery of a cryogen under pressure, which may be a cryogen spray. These systems are typically referred to as cryoablation systems, cryospray systems, cryospray ablation systems, cryosurgery systems, cryosurgery spray systems and/or cryogen spray ablation systems. As typically used, "cryogen" refers to any fluid (e.g., gas, liquefied gas or other fluid known to one of ordinary skill in the art) with a sufficiently low boiling point (i.e., below approximately -<NUM>) for therapeutically effective use during a cryogenic surgical procedure. Suitable cryogens may include, for example, liquid argon, liquid nitrogen and liquid helium. Pseudo-cryogens such as carbon dioxide and liquid nitrous oxide that have a boiling temperature above -<NUM> but still very low (e.g., -<NUM> for N<NUM>O) may also be used.

During operation of a cryospray system, a medical professional (e.g., clinician, technician, medical professional, surgeon etc.) directs a cryogen spray onto the surface of a treatment area via a cryogen delivery catheter. The medical professional may target the cryogen spray visually through a video-assisted device or endoscope, such as a bronchoscope, gastroscope, colonoscope, or ureteroscope. Cryogen spray exits the cryogen delivery catheter at a temperature ranging from <NUM> to -<NUM>, causing the target tissue to freeze or "cryofrost.

Body lumens (e.g., the esophagus, trachea, intestines, etc.) may be treated with cryoablation via radial spray from a catheter. However, as noted above, catheters generally have a low profile for insertion into the body and therefore the radial apertures in the catheter may be remote from the target tissue for treatment. This distance may cause inefficiencies in cryoablation treatment due to spray field interactions from apertures, for example mixing, entrainment, cross-currents and viscous losses, resulting in low tissue coverage and increased therapy time. Various advantages may therefore be realized by the devices, systems and methods of the present disclosure for enhancing radial spray from catheters. <CIT> discloses a body passage cleansing device suitable for being passed through an internal channel of an endoscope.

Methods of treatment by surgery described here below are not part of the claimed invention. The present disclosure in its various embodiments includes methods and devices to enhance radial spray from a catheter. Various embodiments may include extension devices for a radial spray catheter and/or a radial cryospray catheter. Various embodiments may be used with cryosurgery systems configured to laterally extend cryospray gases from a catheter to the target tissue within a body lumen. Extension devices for a radial spray catheter, including radial cryospray catheters and plugs, may emit spray more efficiently and may result in more effective treatment for targeted tissue. Extension devices for radial cryospray catheters or other devices, or radial cryospray catheters or other devices with extended radial apertures may allow for better reorientation of what may be substantially axial components of the flow of cryogens into more lateral spray plumes (such as generally normal to the target tissue) for a more efficient and effective treatment of cryospray. Extension devices may also bring cryospray closer to the target tissue.

In one aspect, an extension device for a radial spray catheter comprises an elongate member with a first open end, a second end, and an elongate lumen therebetween. At least one extension member extends from the elongate member with a first open end in fluid communication with the elongate lumen at one end, a second open end, and an extension lumen therebetween. The extension member(s) is configured to substantially align with at least one radial aperture in a distal end of a catheter. The second end of the elongate member may be closed. An extension device includes a body at the second end of the elongate member that has a diameter larger than a diameter of an outer surface of the elongate member. A body may have an outer diameter that is dimensioned to be larger than a spray lumen of a catheter. A body may have an atraumatic distal portion. A body may be dome-shaped. The extension member(s) may extend radially with respect to a central axis of the elongate lumen. The extension member(s) may be integral with the elongate member. The extension device may include silicone. The extension member(s) may have a length that is configured to extend an effective diameter of a catheter by at least <NUM>%. The radial spray catheter may be a cryospray catheter that delivers cryospray through at least one radial aperture. A diameter of the extension member(s) may be smaller or larger than a diameter of the at least one radial aperture and the diameters may transition conically. The extension member(s) is/are configured to lay substantially parallel to the elongate lumen in a relaxed state and extend radially outward in an activated state. The activated state includes a cryospray being delivered under pressure through the extension lumen. The elongate member may be configured for insertion into the distal end of a catheter.

In another aspect, an extension device for a radial spray catheter may comprise an elongate member with a proximal open end, a closed distal end, and an elongate lumen therebetween. The extension member(s) may extend from the elongate member with a first open end in fluid communication with the elongate lumen, a second open end, and an extension lumen therebetween. The extension member(s) may have an inverted state and an extended state. The extension member(s) may be configured to substantially align with at least one radial aperture in a distal end of the catheter. The extension lumen may have a diminishing diameter that diminishes from the first end to the second end. The extension member(s) may be inverted within the elongate member in the inverted state and may extend radially outward from the elongate member in the extended state. The second open end of the extension member(s) may be inverted within the extension lumen in the inverted state and may be extended outward from the extension lumen in the extended state. A body may be at the closed distal end of the elongate member. The extension lumen may be responsive to pressure from fluid supplied through the catheter to extend the extension member(s) through the at least one radial aperture. The extension lumen may be responsive to pressure from fluid supplied through the catheter to extend the extension member(s) into a substantially straight configuration.

In another aspect, a radial extension catheter for radial spray may comprise a catheter with a first open end, a second end, and a catheter lumen therebetween. At least one radial aperture may be at the second end. The extension member(s) may extend from the at least one radial aperture with a first open end in fluid communication with the catheter lumen, a second open end, and an extension lumen therebetween. The extension member(s) may be integral with the catheter lumen. The extension member(s) may extend from a body that may be inserted into the second end of the catheter. The extension member(s) may be configured to lay substantially parallel to the catheter lumen in a relaxed state and extend radially outward in an activated state. The second open end of the extension member(s) may be inverted within the catheter lumen in an inverted state and may be extended outward from the catheter lumen in an extended state. The extension lumen may have a diminishing diameter that diminishes from the first end to the second end. The extension member(s) may have a length that is configured to extend an effective diameter of the catheter by at least <NUM>%.

The present disclosure is not limited to the particular embodiments described. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting beyond the scope of the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs. Although embodiments of the present disclosure are described with specific reference to radial cryospray systems for use within the upper and lower GI tracts and respiratory system, it should be appreciated that such systems and methods may be used in a variety of other body passageways, organs and/or cavities, such as the vascular system, urogenital system, lymphatic system, neurological system and the like.

As used herein, the conjunction "and" includes each of the structures, components, portions, or the like, which are so conjoined, unless the context clearly indicates otherwise, and the conjunction "or" includes one or the others of the structures, components, portions, or the like, which are so conjoined, singly and in any combination and number, unless the context clearly indicates otherwise.

As used herein, the term "distal" refers to the end farthest away from the medical professional when introducing a device into a patient, while the term "proximal" refers to the end closest to the medical professional when introducing a device into a patient. As used herein, "diameter" refers to the distance of a straight line extending between two points and does not necessarily indicate a particular shape.

In the following an inch corresponds to <NUM>,<NUM>.

The present disclosure generally provides methods and devices to enhance radial spray from a catheter. Various embodiments may include extension devices for a radial spray catheter and/or a radial cryospray catheter.

For example, various embodiments, described here or otherwise, within the scope of the present disclosure, may be used with cryosurgery systems configured to laterally extend cryospray gases (hereafter referred to as "cryospray") from the catheter to the target tissue within a body lumen. Exemplary cryosurgery systems in which the present disclosure may be implemented include, but are not limited to, those systems described in <NUM>,<NUM>,<NUM>, <NUM>,<NUM>,<NUM> and <NUM>,<NUM>,<NUM>, and <CIT> and <CIT>.

In one embodiment of a cyrospray delivery system configured to laterally extend cryospray from a catheter, as illustrated in <FIG>, a catheter <NUM> is connected to a cryotherapy console <NUM> at a catheter interface <NUM>. The catheter <NUM> may be used with an endoscope for delivery into a patient. An image received at the lens on the distal end of the endoscope may be transferred to a monitoring camera which sends video signals via a cable to the monitor <NUM>, where the procedure can be visualized. Built-in software and controls in the console allows the medical professional to control delivery of cryogen from the tank through the catheter <NUM> via a foot petal <NUM>. The catheter <NUM> may have an insulated portion <NUM> and a distal end <NUM>.

As an example of the fluid mechanics of cryospray formation and supply, with reference to the system illustrated in <FIG>, as cryogen (e.g., liquid nitrogen) travels from the tank to the proximal end of cryogen delivery catheter <NUM>, the liquid warms and starts to boil, resulting in cool gas emerging from the distal end <NUM> of catheter <NUM>. The amount of boiling in the catheter <NUM> depends on the mass, surface area, and thermal capacity of catheter <NUM>. When the liquid nitrogen undergoes phase change from liquid to gaseous nitrogen, additional pressure is created throughout the length of catheter <NUM>. This is especially true at a solenoid/catheter junction, where the diameter of the supply tube to the lumen of catheter <NUM> decreases, e.g., from approximately <NUM> inches to approximately <NUM> inches, respectively. The lumen of the catheter <NUM> may have a diameter, e.g., ranging between <NUM> and <NUM> inches. In an alternate embodiment, gas boiling inside the catheter <NUM> may be reduced even greater by the use of insulating materials such as PTFE, FEP, Pebax, and the like, or by surrounding the catheter with a substantially evacuated lumen to help reduce the rate of heat transfer.

With further reference to <FIG>, as an example, the catheter <NUM> is connected to a console <NUM>. The console <NUM> contains the tank that supplies the cryogen. The console <NUM> may include precooling and defrost features. The console <NUM> and/or catheter <NUM> include valving and plumbing to deliver the cryogen under pressure, e.g., delivering low pressure to the distal tip <NUM> of the catheter <NUM>. There may be sensors within the console <NUM> and/or the catheter <NUM> to measure the temperature of the cryogen and/or the tissue. There may be a feedback loop for metered control of cryogen dosing. A pedal <NUM> may be used to control the cryogen delivery, or the cryogen delivery may be timed for a predetermined dosage. The distal tip <NUM> may be openended and/or include radial apertures. The console <NUM> may include software and/or hardware with safety features. The console <NUM> may include an interactive user interface. The console <NUM> may include control settings for a cryospray therapy procedure. The console <NUM> may include cryospray procedure profiles for pre-determined delivering of cryospray.

With reference to <FIG>, an exemplary cyrospray catheter in accordance with embodiments of the present disclosure is illustrated. The catheter <NUM> is placed within a patient such that the distal end <NUM> is in proximity to the target tissue. A medical professional may visualize placement of the distal end <NUM> of the catheter <NUM> via a camera in an endoscope and/or through fluoroscopy. The marking bands <NUM> may be visualized using the camera and/or may be radiopaque for visualization with a fluoroscope. With the distal end <NUM> in position, the medical professional may introduce cryogen into the catheter <NUM>. When the cryogen reaches the distal end <NUM> of catheter <NUM> it exits the distal tip <NUM> and/or the radial apertures <NUM> as a cyrospray towards the target tissue.

With the system of <FIG> and/or catheter of <FIG>, for example, freezing of fluids on the target tissue and/or freezing of the target tissue is apparent to the medical professional by the acquisition of a white color by the target tissue. The white color, resulting from surface frost, indicates the onset of mucosal or other tissue freezing sufficient to initiate destruction of the diseased or abnormal tissue. The operator may use a system timer to freeze for a specified duration once initial cryofrost is achieved in order to control the depth of injury. The delivery of cyrogen may be metered and controlled via a feedback loop that monitors readings from one or more temperature sensors on the catheter shaft. The medical professional may observe the degree of freezing and stop the spray as soon as the surface achieves the desired whiteness of color. The operator may monitor the target tissue to determine when freezing has occurred via the camera integrated into the endoscope. The operator may manipulate the catheter to freeze the target tissue. Once the operation is complete, the catheter, endoscope, and any other instruments, such as a cryodecompression tube for the evacuation of fluids or gases from the patient, are withdrawn from the patient.

The delivery of a multiphase flow of cryogen through the catheter <NUM> leads to the radial apertures <NUM> and/or distal tip <NUM> for cryospray to exit the catheter. Cryogens may partially boil as they travel down the catheter <NUM> and the resulting mixture is released out of the exit points at the distal end <NUM> of the catheter <NUM>. These exit points, as discussed above, may be remote from the target tissue since catheters generally have a low profile, e.g., for insertion through the working channel of an endoscope and into the body. The radial apertures <NUM> in the distal end <NUM> of the catheter <NUM> are meant to emit cryospray onto the inner wall of tissue in a body lumen.

When cryospray exits the distal end <NUM> of the catheter <NUM> through the radial holes <NUM>, it does so typically in an orthogonal direction or angle from the catheter <NUM> (i.e., along an axis transverse to the longitudinal axis of the catheter). Increasing the ratio of length to diameter of these apertures may improve spray orthogonality, which may improve cooling efficiency. As the flow transitions from a longitudinal direction to a radial direction, a longer aperture (or lumen, nozzle, or the like) may allow for increased radial flow momentum. Cooling efficiency of the radial spray may be improved because the spray may impinge substantially normal to the tissue, reducing the amount of cryogen spray that is deflected when it hits warm tissue.

Referring to <FIG>, an embodiment of an extension device for enhancing radial spray from a catheter according to the present disclosure includes an elongate member <NUM> with a proximal open end 302p, a distal end 302d, and an elongate lumen <NUM> between the ends. Numerous extension members <NUM> extend from the elongate member <NUM>. The extension members <NUM> have a first open end 306c in fluid communication with the elongate lumen <NUM>, a second open end 306r, and an extension lumen <NUM> between the ends. The extension members <NUM> extend radially from a central axis of the elongate lumen <NUM>. The distal end 302d of the elongate member <NUM> is closed by a body <NUM>. The body <NUM> has a diameter larger than a diameter of the outer surface of the elongate member <NUM>. The body <NUM> has an atraumatic dome shape.

Referring to <FIG>, an embodiment of an extension device for a catheter <NUM> according to the present disclosure includes positioning an extension device, e.g., the device of.

<FIG>, into the distal end of a catheter <NUM>. The proximal open end 402p of the elongate member <NUM> is directed towards the proximal direction 414p of the catheter lumen <NUM>. The distal end 402d of the elongate member <NUM> is directed towards the distal tip 414d of the catheter lumen <NUM> such that the body <NUM> abuts the distal tip 414d of the catheter lumen <NUM>. The body <NUM> has a larger diameter than the lumen <NUM> such that it cannot be inserted into the lumen <NUM>. Extension members <NUM> extend from the elongate member <NUM> through the radial apertures <NUM> that they align with.

One should appreciate that the cross-sectional view of <FIG> illustrates only a limited number of extension members, and that the inclusion of more extension members aligned in a first row around the circumference of the catheter with the extension members shown, and/or a second distal row of radial apertures <NUM> (<NUM> in <FIG>), such as illustrated in the catheter embodiment of <FIG>, and corresponding extension members, is possible. As shown the two rows of apertures <NUM> are circumferentially offset from each other about a longitudinal axis of the catheter <NUM> such that a center point of the apertures <NUM> do not share the same cross-sectional plane between the proximal and distal rows of the apertures <NUM>.

The extension devices of the present disclosure, e.g., the embodiment in <FIG>, effectively brings the exit points for cryospray (i.e., the second ends 406r) closer to the target tissue <NUM> of a body lumen <NUM>. The extension members <NUM> have a first open end 406c in fluid communication with the elongate lumen <NUM> at one end, a second open end 406r in close proximity to the target tissue <NUM>, and an extension lumen <NUM> between the ends. With reference, for example to the system of <FIG>, as cryogens are introduced to the proximal end of the catheter <NUM>, the cryogens travel to the distal end of the catheter <NUM>. As the cryogens travel from the tank and console <NUM> through the catheter, they are exposed to warmer temperatures and viscous resistance forces from the catheter <NUM>, causing liquid cryogen to boil into cryospray gases. Once the mixed cryogens reach the distal end of the catheter <NUM>, they enter the elongate lumen <NUM>. The body <NUM> at the distal end 402d of the elongate lumen closes the lumen and prevents the cryogens from escaping out of the distal tip 414d of the catheter lumen <NUM>. The body <NUM> may also increase resistance. As pressure in the elongate lumen <NUM> builds, the cryogens are forced out of the elongate lumen <NUM>, through the first end 406c, and into the extension lumens <NUM>. The cryogens then exit the second end 406r in a cryospray that is in closer proximity to the target tissue <NUM> than the exits of the radial apertures <NUM> without the extension members <NUM>. In some cases, the extension members may increase the effective profile of a catheter by up to at least <NUM> %, or from about <NUM>% to <NUM>%, or more.

In various embodiments, described here or otherwise, within the scope of the present disclosure, the proximal portion of the body may be shaped to help distribute the spray evenly all around the elongate lumen, e.g., a convex or concave shape. The distal portion of the body may take on several shapes. An atraumatic shape such as a dome may reduce the risk of trauma to the patient, reducing the risk of abrasions, perforations, etc., and/or reduce the risk of damaging the catheter within the working channel or the endoscope or vice versa. Various overall diameters of the body may be adjusted to cover the distal end of a catheter tip in order to protect the patient, device or endoscope.

In various embodiments, described here or otherwise, within the scope of the present disclosure, there may be any number of extension members. The number of extension members could match up with the number of radial apertures in the catheter, but there could be less than the number of apertures in the catheter. With fewer extension members than radial apertures, some of the catheter apertures may be blocked, increasing the flow rate through the extension members. Merely one extension member may be used for targeted treatment of a target tissue. The extension members may take on various shapes and angles. The extension members may be angled non-radially to adjust the cryospray pattern, e.g., proximally or distally. The second ends of the extension members may include nozzles of various shapes to further restrict and direct cryospray flow. The extension members may vary in thickness to adjust overall strength. The extension members may have various outer diameters that may be significantly smaller than the radial apertures in order to further restrict flow while the outer surface of elongate member blocks the unfilled portion of the radial aperture. The extension members may have a relaxed state, where they lay substantially parallel to the catheter lumen in a relaxed state along the elongate member or catheter, and an activated or extended state when fluid is forcibly supplied through the elongate lumen where they are partially or substantially straightened in an upright position and extend radially outward in an activated state. The extension members may extend radially with respect to a central axis of the elongate lumen. The extension members may be integral with the elongate member.

In various embodiments, the extension device may be held within a catheter via frictional forces between the outer surface of the elongate member and the inner surface of the catheter lumen. The extension members may also fix the extension device in place via resistance from the radial apertures on the extension members in the proximal direction. An adhesive applied to the elongate member, the body, or at least one of the extension members may fix the extension device in position within the catheter. The elongate member may be configured for insertion into the distal end of a catheter, e.g., curved edges at a proximal end of the elongate member may ease insertion. The extension members may be overmolded to a device and/or a catheter.

In various embodiments, described here or otherwise, within the scope of the present disclosure, a catheter may have a first open end, a second end, a catheter lumen therebetween, and at least one radial aperture at the second end. The catheter may include at least one extension member extending from the at least one radial aperture with a first open end in fluid communication with the catheter lumen and a second end open end with an extension lumen therebetween. The extension member(s) may extend from a body that is integral with the catheter. Alternatively, the extension member(s) may extend from a body that is inserted into the second end of the catheter in accordance with an embodiment of the disclosure.

Referring to <FIG>, an embodiment of an extension member for an extension device according to the present disclosure includes an extension member <NUM> attached to an elongate member <NUM>. The extension member <NUM> may lay substantially parallel to the catheter lumen along the elongate member <NUM> or catheter in a relaxed state as illustrated in <FIG>. The extension member <NUM> is in the relaxed state when there is no fluid flow through the extension member <NUM>. The extension member <NUM> may be thin-walled so as to lay limp under its own weight. The extension member <NUM> may be biased to face a proximal direction when in the relaxed state to ease distal insertion of the catheter into an endoscope and/or patient. The elongate member <NUM> may be more rigid so as to maintain the shape of the elongate lumen <NUM>. The extension member <NUM> may be in the activated, or extended state, when a fluid is flowed through the extension member <NUM>, as illustrated in <FIG>. The extension member <NUM> is substantially straight in this state.

Referring to <FIG>, embodiments of extension members for extension devices according to the present disclosure but not according to the invention include an extension member <NUM> with an extension lumen <NUM> having a diminishing diameter that diminishes from the first end 602c toward the second end 602r. The extension member <NUM> may invert into the elongate lumen <NUM> of the elongate member <NUM> in the relaxed/inverted state, as illustrated in <FIG>. The extension member <NUM> may extend out of the elongate lumen <NUM> and away from the elongate member <NUM> in the extended/excited state as illustrated in <FIG>. The extension member <NUM> may extend out of the elongate lumen <NUM> and partially away from the elongate member <NUM>, while still being partially inverted within the extension lumen <NUM>, in the extended or partially extended state as illustrated in 6B. The configuration illustrated in <FIG> may be achieved by a low flow of fluid through the extension lumen <NUM> or it may be achieved by the extension member <NUM> colliding with an object or tissue before fully extending.

The embodiments described herein may be made of silicone, nitinol, spring steel wire, and the like, or a combination thereof. Various thicknesses may be used to achieve a desired rigidity of some parts over others. For example, the walls of the elongate member may be thicker than the walls of the extension member such that the elongate member substantially maintains its shape while the extension member is limp and pliable. The extension member may be made of any pliable and polymeric material (e.g., silicone), which is biocompatible and compatible with a fluid (e.g., cryogen) traveling from the elongate member and/or catheter through the extension member. The extension member may be a metallic tube, for example, superelastic nitinol, or the like. The extension member may be welded, bonded, and/or friction fit to the radial apertures. For some systems, such as with low pressure flows, the extension member may spring out to a desired orientation. This may be accomplished by delivering a device in a sheath and retracting the sheath to allow the spring structure of the extension member to actuate.

An embodiment of a non claimed method of enhancing spray from a catheter may include inserting a device with at least one extension member into a distal end of the catheter. The device may be rotated such that at least one extension member substantially lines up with at least one radial aperture of the catheter. Alternatively, the catheter may be manufactured with the extension device body in place or the extension member(s) may be integral with the catheter lumen. The device may be held in place while a medical professional introduces a fluid into a proximal end of the catheter. The fluid may have enough pressure to extend the at least one extension member through the at least one radial aperture. The device and/or catheter may be inserted into the body lumen of a patient. A treatment fluid, e.g., cryogen, may be introduced into a proximal end of the catheter. The treatment fluid may be at a pressure high enough to extend the at least one extension member into a substantially straight configuration.

Referring to <FIG>, an embodiment of an extension catheter according to the present disclosure includes extension members <NUM> that may be configured to lay substantially parallel to a lumen of a catheter <NUM> in a relaxed state and extend radially outward in an activated state. The extension members <NUM> may be integral with the catheter or an extension device may be an accessory or part of a kit with the catheter <NUM>. The first end 702c of the extension members is in fluid communication with the lumen of the catheter <NUM>. The second end 702r is biased proximally when the extension members are in a relaxed state. <FIG> illustrates the extension members <NUM> in a relaxed state.

Referring to <FIG>, an embodiment of an extension catheter according to the present disclosure but not according to the invention includes extension members <NUM> with a second open end 702r of the extension members702 that is inverted within the lumen of the catheter <NUM> in an inverted state. The extension members <NUM> may be integral with the catheter or an extension device may be an accessory or part of a kit with the catheter <NUM>. The extension members <NUM> may extend outward from the catheter <NUM> in an extended state. The extension lumen <NUM> of the extension members <NUM> have a diminishing diameter that diminishes from the first end 702c to the second end 702r. <FIG> illustrates the extension members <NUM> in an inverted state. The extension members <NUM> may have a length that is configured to extend an effective diameter of the catheter <NUM> by at least <NUM>%.

Claim 1:
An extension device for a radial spray catheter (<NUM>) comprising:
an elongate member (<NUM>) with a first open end (302p), a second end (302d), and an elongate lumen (<NUM>) therebetween;
a body (<NUM>) at the second end (302d) of the elongate member (<NUM>) with a diameter larger than a diameter of an outer surface of the elongate member (<NUM>); and
at least one extension member (<NUM>) extending from the elongate member (<NUM>) with a first open end (306c) in fluid communication with the elongate lumen (<NUM>) at one end (306c), a second open end (306r), and an extension lumen (<NUM>) therebetween;
wherein the at least one extension member (<NUM>) is configured to substantially align with at least one radial aperture in a distal end of the radial spray catheter; characterized in that
the at least one extension member (<NUM>) is configured to lay substantially parallel to the elongate lumen in a relaxed state and extend radially outward in an activated state; and
wherein the activated state comprises a cryospray being delivered under pressure through the extension lumen.