This disclosure generally relates to medical devices, and more particularly, to medical devices and associated techniques for forming shunts.
Heart failure is a common syndrome in which a patient's heart output is insufficient to meet the body's needs. In some forms of heart failure, excess pressure can occur in the left atrium, causing a variety of symptoms. Patients experiencing heart failure currently have limited treatment options.
Interatrial shunting is a technique to decompress the left atrium in patients suffering from heart failure. During the procedure, a blood flow pathway is created between the right atrium and the left atrium such that blood flows between them. In a typical procedure, the septal wall separating the atria is cut with a puncturing device and a mechanical device such as a stent is left in place to prevent tissue overgrowth and to maintain the shunt.
The present disclosure describes systems, devices, and techniques for creating a fluid pathway, or shunt, between the left atrium and right atrium of a heart of a patient. The shunt can be used, for example, to treat patients with heart failure. Many existing interatrial shunting procedures implant a device into the interatrial septum to maintain such a shunt. Some other interatrial shunting procedures forgo an implant and rely on a cutting tool to create a controlled opening within the interatrial septum, and a cryoablation device to ensure myocardial cell death to prevent regrowth. These avoid a permanent implant in the heart, reducing risk of failure and its potential prevention from future trans-septal catheter access.
Some examples described herein employ a cryoablation balloon. The distal outer surface of the cryoablation balloon, which contacts the interatrial septum, has an insulated region and a cooling region (e.g., a non-insulated region). The insulated region has a low thermal conductivity to protect the tissue from the cooling of a cryogenic agent in the cryoablation balloon. The cooling region is configured to have a specified shape to apply an ablated profile in the tissue. That is, the cooling region kills the cells of the tissue of the interatrial septum it is in contact with, altering the mechanical properties of that region of the septum. This cryo-ablated tissue has a significantly lower tensile strength compared to untreated regions of the interatrial septum. Thus, the ablated tissue is primed for a controlled tearing as the balloon dilates a puncture opening.
After performing the initial ablation with the distal outer surface of the balloon to leave the desired ablation profile, the balloon is deflated and crossed partially through a puncture in the ablated profile from the right atrium into the left atrium. The balloon may then be inflated with a non-cryogenic agent (e.g., air, nitrous oxide, etc.) in a controlled manner to dilate the opening through which the balloon passed to a desired size. Here, because the ablated tissue has lower tensile strength, there is a higher likelihood for a tear propagation to occur along the arms of the ablated tissue profile. Accordingly, a multicuspid, multi-leaflet interatrial shunt is created between the left and right atria to treat heart failure.
In one example, a surgical apparatus includes an elongate tool body having at least one lumen and a distal portion. The surgical apparatus further includes an inflatable balloon on the distal portion, the inflatable balloon configured to be inflated via the lumen. The inflatable balloon includes a distal outer surface configured for contacting an interatrial septum of a heart of a patient, and an ablation region of the distal outer surface of the inflatable balloon for extracting heat from the interatrial septum when the interior chamber of the balloon receives the cryogenic agent. The ablation region is disposed on the distal outer surface of the inflatable balloon in a manner that the ablation region creates a multicuspid ablation pattern when the inflatable balloon receives the ablation energy.
In another example, a surgical apparatus includes an elongate tool body having at least one lumen and a distal portion. The elongate tool body includes a distal puncturing tip for puncturing an interatrial septum of a heart of a patient to create an opening, and an inflatable balloon configured to be inflated via the lumen of the elongate tool body. The inflatable balloon includes a distal outer surface configured for contacting the interatrial septum, and an ablation region of the distal outer surface of the inflatable balloon for ablating the interatrial septum when the inflatable balloon receives the ablation energy. The ablation region is disposed on the distal outer surface of the inflatable balloon in a manner that the ablation region creates a multicuspid ablation pattern when the inflatable balloon receives the ablation energy. The inflatable balloon is configured to advance through the opening and to dilate the opening causing tissue to tear along the multicuspid ablation pattern.
In another example, a method includes creating a puncture through an interatrial septum of a heart of a patient. The method further includes inflating an inflatable balloon having a distal outer surface comprising an ablation region, bringing the distal outer surface of the inflatable balloon into contact with the interatrial septum proximal to the puncture, and applying ablation energy to the interatrial septum through the ablation region of the inflatable balloon, to create a multicuspid ablation pattern.
The details of one or more examples of the techniques of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques will be apparent from the description and drawings, and from the claims.
In various aspects, the present disclosure provides for a surgical apparatus that facilitates a controlled tearing or cleaving of ablated tissue to create a multicuspid, multi-leaflet interatrial shunt between the left and right atria of a patient's heart. This shunt alleviates elevated pressure in the left atrium caused by heart failure, by recycling the blood through the system back into the right atrium. In some aspects, scar tissue replaces the need for a stent for preventing tissue regrowth and to maintain the shunt. Having a shunt without a stent or similar mechanical implant reduces or eliminates the risk of stent failure. In further aspects, the disclosed surgical apparatus creates a multicuspid, multi-leaflet opening that exhibits improved behavior based on the differential pressure between the left and right atria, compared to a non-cuspid (e.g., circular) opening. Further, the disclosed surgical apparatus simplifies the procedure for creating a multi-leaflet shunt without requiring a mechanical cutter with blades.
Handle 24 includes one or more interfaces with control unit 14, which is illustrated with an optional display 35. For example, handle 24 may be coupled with fluid supply reservoir 16 and a fluid recovery reservoir or scavenging system 40. Fluid supply reservoir 16 may include any suitable number of fluid supply reservoirs for any suitable fluids, including, for example, a cryogenic agent such as liquid nitrogen or liquid nitrous oxide, and a non-cryogenic agent such as air or gaseous nitrous oxide. According to an aspect of the disclosure, each reservoir of the fluid supply reservoirs 16 may separately deliver a respective agent via a lumen of the elongate body 18 to the surgical apparatus 102, as described further below. In some examples, the same medium may be used as a cryogenic agent and a non-cryogenic agent. For example, nitrous oxide may be introduced into the surgical apparatus 102 in a liquid form to deliver cryogenic energy to the surgical apparatus 102, and nitrous oxide may be introduced into the surgical apparatus 102 in a gaseous form to, e.g., inflate a balloon at the surgical apparatus 102. Control unit 14 further includes a processing circuit 33 for controlling electronic operations of the system 10, and an interface with a generator 37 for generating electromagnetic energy for, e.g., pulsed field ablation (PFA) and/or radio frequency (RF) ablation via surgical device 102. In the illustrated example, electromagnetic energy generator 37 includes an optional user interface 39. In another example (not illustrated), control unit 14 may further include an ultrasound generator for delivering ultrasound energy to surgical apparatus 102.
In some examples, the surgical apparatus 102 may perform ablation of tissue via electromagnetic or ultrasound energy. While in other examples, the surgical apparatus 102 may perform ablation of tissue via cryogenic energy.
A waist 110 between the distal lobe 104 and proximal lobe 106 has a controlled diameter (e.g., a diameter between about 5 and 15 mm) for dilating an opening in the interatrial septum. The distal outer surface of the balloon 105 has at least one insulated region 112 and at least one ablation region (e.g., cooling region 114). When the balloon 105 is inflated, a cryogenic agent may be introduced to the balloon 105 via a lumen in the elongate tool body 108. When the cryogenic agent is introduced into the balloon 105, the cooling region 114 extracts heat from tissue with which it is in contact, while the insulated region 112 protects or insulates tissue from a cooling effect. A distal tip 116 of the elongate tool body 108 of the surgical apparatus 102 centers the cooling region 114 and assists in holding the surgical apparatus in position during a cryoablation procedure.
As indicated above, according to some aspects of this disclosure, rather than cryoablation, ablation energy may be delivered to a surgical apparatus 102 via electromagnetic or ultrasound energy. For example,
A surgical apparatus 102 may enter (1102) a patient's heart by being inserted into a suitable blood vessel such as the femoral vein and guided to the heart.
A puncture 306 may be created (1104) in the interatrial septum using any suitable tool, such as a needle, a knife, an electro-ablation blade, etc., which may be included as part of or advanced through the elongate tool body 108, or may be a separate element advanced through a catheter and/or over a guidewire. In some examples, a guidewire (not illustrated) of or advanced through the elongate tool body 108 of the surgical apparatus may be inserted (1106) into the puncture 306 for guiding and aligning the surgical apparatus 102 to the puncture 306. In some examples, a guidewire may be inserted into the puncture 306 by means other than elongate tool member 108, and elongate tool body 108 may be advanced to puncture 306 over the guidewire. In any case, as illustrated in
As discussed above, in some examples the balloon 105 may be inflated prior to being brought into contact with the interatrial septum 402. But in other examples, the balloon 105 may inflate after being brought into contact with the interatrial septum 402. Inflation of the balloon 105 may be performed by introducing a non-cryogenic agent such as air or gaseous nitrous oxide into an interior chamber of the balloon 105 via a lumen in elongate tool body 108 from the control unit 14 (see
In some aspects of this disclosure, where the surgical apparatus is configured for cryoablation of tissue (e.g., as described in connection with
As illustrated in
When the ablation region 114 is in contact with the contact region 302 of the interatrial septum 402, the distal tip 116 of the elongate tool body 108 is configured to align or stabilize the surgical apparatus 102. By applying a suitable pressure to press the elongate tool body 108 of the surgical apparatus 102 against the interatrial septum 402, the distal lobe 104 of the balloon 105 may conform to the surface of the interatrial septum 402, and/or the interatrial septum 402 may deform to wrap around a portion of the distal outer surface of the distal lobe of the cryoablation balloon.
According to some examples, a spray pattern of the cryogenic agent within the balloon may be adapted to spray the cryogenic agent on the cooling region 114 while avoiding spraying the cryogenic agent on the insulated region 112. For example,
In some examples, a rotational fixation mechanism may be employed to prevent the balloon 105 from rotating, although other examples may omit such mechanism. After a suitable amount of time for ablation of the contact region 302 to take place (e.g., about 4 to 8 minutes in a cryoablation example), the surgical apparatus may deflate (1116) the interior chamber of the balloon(s) 105 and allow the tissue to thaw. For example, a thawing wait time may be established based on the temperature of the balloon 105, wherein the interior chamber of the balloon 105 automatically deflates when it reaches a suitable temperature (e.g., 20° C.).
As shown in
Because of the shaped ablation region 302, illustrated in
In the example described above, the elongate tool body 108 of the surgical apparatus 102 includes a dual-lobe balloon 105 having a distal lobe 104 and a proximal lobe 106. However, in other examples within the scope of this disclosure, e.g., as illustrated in
A surgical apparatus 102 may create (1302) a puncture 306 through an interatrial septum 402 of a patient's heart. The surgical apparatus 102 may use any suitable tool to create the puncture, such as a needle, a knife, an electro-ablation blade, etc. In some examples, the puncturing/cutting tool may be integrated to the surgical apparatus 102, while in other examples, the puncturing/cutting tool may be a separate tool. In some examples, the distal tip 116 of the surgical apparatus 102 may have a tapered profile providing for puncturing the interatrial septum.
An elongate tool body 108 of the surgical apparatus 102 may inflate (1304) an inflatable balloon. Here, the inflatable balloon includes a distal outer surface having an ablation region (e.g., a cooling region 114, and/or one or more electrodes 202, see
The surgical apparatus 102 may bring (1306) the distal outer surface of the inflatable balloon into contact with the interatrial septum 402, proximal to the puncture 306. Here, the distal tip 116 of the surgical apparatus 102 may remain in the puncture 306 to center the surgical apparatus 102 and stabilize its position at the location where ablation will take place.
The surgical apparatus 102 may apply an ablation energy to the inflatable balloon 105 (1308). For example, the surgical apparatus 102 may apply a cryogenic agent to the interior surface of the cryoablation balloon. In this way, a cryoablation balloon extracts heat from the interatrial septum 402 through the cooling region 114, to create a multicuspid ablation pattern 302. In another example, the surgical apparatus 102 may apply electromagnetic energy to one or more electrodes on the distal outer surface of the inflatable balloon. In this way, an electromagnetic ablation electrode may ablate the interatrial septum 402 to create a multicuspid ablation pattern 302.
It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a surgical apparatus. The following examples are examples of systems, devices, and methods described herein.
Example 1: In some examples, a surgical apparatus includes an elongate tool body including at least one lumen and a distal portion, and an inflatable balloon on the distal portion, the inflatable balloon configured to be inflated via the lumen. The inflatable balloon includes a distal outer surface configured for contacting an interatrial septum of a heart of a patient, and an ablation region of the distal outer surface of the inflatable balloon configured for ablating the interatrial septum when the inflatable balloon receives the ablation energy. The ablation region is disposed on the distal outer surface of the inflatable balloon in a manner that the ablation region creates a multicuspid ablation pattern when the inflatable balloon receives the ablation energy.
Example 2: In some examples of the surgical apparatus of Example 1, the inflatable balloon is further configured for receiving a non-cryogenic agent via the lumen, wherein the elongate tool body further comprises a distal puncturing tip for puncturing the interatrial septum to create an opening, and wherein the inflatable balloon is configured to advance through the opening and to dilate the opening causing tissue to tear along the multicuspid ablation pattern.
Example 3: In some examples of the surgical apparatus of Examples 1 or 2, the inflatable balloon includes a dual-lobe balloon having a distal lobe and a proximal lobe with a waist in between the distal lobe and the proximal lobe, and wherein the waist is configured for dilating the opening causing the tissue to tear along the multicuspid ablation pattern.
Example 4: In some examples of the surgical apparatus of Example 3, a diameter of the distal lobe and the proximal lobe is between 15-30 mm, and a diameter of the waist is between 5-15 mm.
Example 5: In some examples of the surgical apparatus of Examples 1 to 4, the elongate tool body further includes a guidewire lumen configured for advancing over a guidewire.
Example 6: In some examples of the surgical apparatus of Examples 1 to 5, the ablation energy includes electromagnetic energy. The ablation region includes one or more electrodes shaped to create the multicuspid ablation pattern when the one or more electrodes are energized with the ablation energy.
Example 7: In some examples of the surgical apparatus of Examples 1 to 6, the multicuspid ablation pattern includes a multi-armed star.
Example 8: In some examples of the surgical apparatus of Examples 1 to 5, the ablation energy includes cryogenic energy. The apparatus further includes an insulated region on the distal outer surface of the inflatable balloon for insulating the interatrial septum from cooling from a cryogenic agent. Further, the ablation region and the insulated region are shaped to create the multicuspid ablation pattern.
Example 9: In some examples of the surgical apparatus of Example 8, the at least one lumen includes a first lumen configured to receive the cryogenic agent and a second lumen configured to receive an insulating agent, wherein the insulated region comprises an inner balloon separate from and coupled to an inner surface of the inflatable balloon. Here, the inner balloon is configured to inflate with the insulating agent for shielding the insulated region from the cryogenic agent.
Example 10: In some examples of the surgical apparatus of Examples 8 to 9, the insulated region and the cooling region are configured to give the cooling region a shape of a multi-armed star.
Example 11: In some examples of the surgical apparatus of Examples 8 to 10, the cooling region has a shape of a three-armed star.
Example 12: In some examples of the surgical apparatus of Examples 8 to 11, the surgical apparatus further includes a plurality of cryogenic agent injection ports within the inflatable balloon, configured to spray the cryogenic agent toward an inner surface of the cooling region.
Example 13: In some examples, a surgical apparatus includes an elongate tool body including at least one lumen and a distal portion. The elongate tool body includes a distal puncturing tip for puncturing an interatrial septum of a heart of a patient to create an opening; and an inflatable balloon configured to be inflated via the lumen of the elongate tool body. The inflatable balloon includes a distal outer surface configured for contacting the interatrial septum; and an ablation region of the distal outer surface of the inflatable balloon for ablating the interatrial septum when the balloon receives the ablation energy. The ablation region is disposed on the distal outer surface of the inflatable balloon in a manner that the ablation region creates a multicuspid ablation pattern when the inflatable balloon receives the ablation energy. The inflatable balloon is configured to advance through the opening and to dilate the opening causing tissue to tear along the multicuspid ablation pattern.
Example 14: In some examples of the surgical apparatus of Example 13, the inflatable balloon includes a dual-lobe balloon having a distal lobe and a proximal lobe with a waist in between the distal lobe and the proximal lobe, and wherein the waist is configured for dilating the opening causing the tissue to tear along the multicuspid ablation pattern.
Example 15: In some examples of the surgical apparatus of Examples 13 to 14, a diameter of the distal lobe and the proximal lobe is 15-30 mm, and a diameter of the waist is 5-15 mm.
Example 16: In some examples of the surgical apparatus of Examples 13 to 15, the ablation region has a shape of a multi-armed star.
Example 17: In some examples of the surgical apparatus of Examples 13 to 16, the cooling region has a shape of a three-armed star.
Example 18: In some examples of the surgical apparatus of Examples 13 to 17, the ablation energy includes cryogenic energy. The inflatable balloon includes an interior chamber for receiving a cryogenic agent, and an insulated region of the distal outer surface of the inflatable balloon for insulating the interatrial septum from cooling from the cryogenic agent.
Example 19: In some examples of the surgical apparatus of Examples 13 to 17, the ablation energy includes electromagnetic energy. The ablation region further includes one or more electrodes shaped to create the multicuspid ablation pattern when the one or more electrodes are energized with the ablation energy.
Example 20: In some examples, a surgical method includes creating a puncture through an interatrial septum of a heart of a patient; inflating an inflatable balloon having a distal outer surface comprising an ablation region; bringing the distal outer surface of the inflatable balloon into contact with the interatrial septum proximal to the puncture; and applying ablation energy to the interatrial septum through the ablation region of the inflatable balloon, to create a multicuspid ablation pattern.
Example 21: In some examples of the surgical method of Example 20, the surgical method further includes deflating the inflatable balloon; advancing a distal portion of the inflatable balloon through the puncture; and inflating the inflatable balloon with a non-cryogenic agent to cause the tissue to tear along the multicuspid ablation pattern.
Example 22: In some examples of the surgical method of Examples 20 to 21, advancing the distal portion of the inflatable balloon through the puncture includes advancing the inflatable balloon over a guidewire.
Example 23: In some examples of the surgical method of Examples 20 to 22, the method further includes inflating an inner balloon coupled to an inner surface of the inflatable balloon with an insulating agent.
Example 24: In some examples of the surgical method of Examples 20 to 23, the ablation energy includes electromagnetic energy. The ablation region includes one or more electrodes on a surface of the inflatable balloon, shaped to create the multicuspid ablation pattern when the one or more electrodes are energized with the ablation energy.
Example 25: In some examples of the surgical method of Examples 20 to 23, the ablation energy includes cryogenic energy. The ablation region includes a cooling region.
The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors or processing circuitry, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. The term “processor” or “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit comprising hardware may also perform one or more of the techniques of this disclosure.
Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various operations and functions described in this disclosure. In addition, any of the described units, circuits or components may be implemented together or separately as discrete but interoperable logic devices. Depiction of different features as circuits or units is intended to highlight different functional aspects and does not necessarily imply that such circuits or units must be realized by separate hardware or software components. Rather, functionality associated with one or more circuits or units may be performed by separate hardware or software components or integrated within common or separate hardware or software components.
The techniques described in this disclosure may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions that may be described as non-transitory media. Instructions embedded or encoded in a computer-readable storage medium may cause a programmable processor, or other processor, to perform the method, e.g., when the instructions are executed. Computer readable storage media may include random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, magnetic media, optical media, or other computer readable media.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.
This application claims the benefit of U.S. Provisional Application No. 63/479,669 filed Jan. 12, 2023, the entire contents of which is incorporated herein by reference.
Number | Date | Country | |
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63479669 | Jan 2023 | US |