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WO2025217198A1 - Dispositif de canal pour septum auriculaire - Google Patents

Dispositif de canal pour septum auriculaire

Info

Publication number
WO2025217198A1
WO2025217198A1 PCT/US2025/023713 US2025023713W WO2025217198A1 WO 2025217198 A1 WO2025217198 A1 WO 2025217198A1 US 2025023713 W US2025023713 W US 2025023713W WO 2025217198 A1 WO2025217198 A1 WO 2025217198A1
Authority
WO
WIPO (PCT)
Prior art keywords
energy
diameter
stent
atrial septal
atrial
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/US2025/023713
Other languages
English (en)
Inventor
Achu Geetha BYJU
Balakrishna Haridas
Michael Anthony Belfort
Kwon Soo Chun
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Texas A&M University System
Texas A&M University
Original Assignee
Texas A&M University System
Texas A&M University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Texas A&M University System, Texas A&M University filed Critical Texas A&M University System
Publication of WO2025217198A1 publication Critical patent/WO2025217198A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/056—Transvascular endocardial electrode systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/11—Surgical instruments, devices or methods for performing anastomosis; Buttons for anastomosis
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14—Probes or electrodes therefor
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14—Probes or electrodes therefor
    • A61B18/1492—Probes or electrodes therefor having a flexible, catheter-like structure, e.g. for heart ablation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
    • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
    • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
    • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/10—Balloon catheters
    • A61M25/104—Balloon catheters used for angioplasty
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/06—Electrodes for high-frequency therapy
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/40—Applying electric fields by inductive or capacitive coupling ; Applying radio-frequency signals
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/00234—Surgical instruments, devices or methods for minimally invasive surgery
    • A61B2017/00238—Type of minimally invasive operation
    • A61B2017/00243—Type of minimally invasive operation cardiac
    • A61B2017/00247—Making holes in the wall of the heart, e.g. laser Myocardial revascularization
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B2017/00526—Methods of manufacturing
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B2017/00982—General structural features
    • A61B2017/00986—Malecots, e.g. slotted tubes, of which the distal end is pulled to deflect side struts
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/11—Surgical instruments, devices or methods for performing anastomosis; Buttons for anastomosis
    • A61B2017/1139—Side-to-side connections, e.g. shunt or X-connections
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2250/0014—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
    • A61F2250/0039—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis differing in diameter

Definitions

  • the present disclosure relates generally to a device for the creation and/or enlargement of an atrial septal channel, for example, an atrial septal channel enlargement device and/or an atrial septal channel creation device, and to methods and systems for using the same in the treatment of a patient.
  • HLHS Hypoplastic Left Heart Syndrome
  • HLHS is a congenital birth defect occurring in about 1 in 5000 infants and accounts for 3% of all births with congenital birth defects. While this condition would have necessarily resulted in the death of the neonate in the past, modem surgical techniques involving staged surgical palliation have resulted in a survival rate as high as 76%.
  • the Norwood, Glenn, and Fontan series of surgeries reconfigures the cardiac circulation to support both systemic and pulmonary blood flow with a single ventricle where systemic blood flow passively flows to the pulmonary vascular bed before returning to the heart for pumping to the systemic bed.
  • HLHS left heart structures are underdeveloped and unable to support normal cardiac function. More particularly, with HLHS, the left side of the fetal heart is underdeveloped and incapable of proper function.
  • the normally-developed fetal heart has an atrial septal opening, the foramen ovale, that supports cross-atrial blood flow to supply oxygenated blood to the body.
  • Infants with HLHS normally rely upon the interconnection of the systemic and pulmonary blood flows through the foramen ovale and ductus arteriosus for survival.
  • l/RAS atrial septum
  • FCI Fetal cardiac interventions
  • a balloon septostomy may be performed in attempts to expand or enlarge a septal opening.
  • these procedures are limited in the size of the balloon that may be used because of the small introducer.
  • An example of a channel having a reduced size compared to the balloon is illustrated in Fig. 1 B.
  • these devices are delivered under ultrasound guidance through the maternal abdominal wall, uterine wall, fetal chest, and into the fetal heart, and as such, the precision available to the surgeon is quite limited.
  • both the mother and the fetus can move relative to each other and the surgical devices.
  • Such movements when coupled with the hard-to-place conventional cylindrical-shaped stents, make the surgical operations especially challenging.
  • These stents are also not designed for use across a thin-walled motile structure and present a grave risk of stent migration out of the septum and into either atrium.
  • Heart failure affects over 5 million patients in the United States and the cost of this disease is expected to exceed $70 billion by 2030.
  • 90% of hospitalizations for heart failure show symptoms of pulmonary congestion to varying degrees depending on the types of heart failure, such as (a) heart failure with preserved ejection (HFpEF), (b) heart failure with mid-range ejection fraction (HFmrEF), or (c) heart failure with reduced ejection (HFrEF).
  • Creating an atrial septal channel can help decompress the left atrium, thereby reducing pulmonary pressures and alleviating symptoms.
  • Patients with pulmonary atrial hypertension who have a patent foramen ovale are known to live longer than those without, making the creation of an atrial septal channel a promising treatment for patients with this condition.
  • patients with severe mitral valve disease such as mitral stenosis or regurgitation, may also benefit from an atrial septal channel to relieve left atrial hypertension and improve hemodynamic stability.
  • the procedure may also be used on patients under extracorporeal membrane oxygenation (ECMO) support who experience pulmonary edema.
  • ECMO extracorporeal membrane oxygenation
  • the device comprises a cylindrical body section comprising a radiofrequency (RF) energy source, a first flanged section extending from a first end of the cylindrical body section and having a first diameter, and a second flanged section extending from a second end of the cylindrical body section and having a second diameter.
  • the device is configured to expand within an atrial septal channel to increase the first diameter of the first flanged section, increase the second diameter of the second flanged section, and position the RF energy source in contact with an inner surface of the atrial septal channel.
  • the first diameter, the second diameter, and a body diameter of the cylindrical body section are approximately equal when the device is in an unexpanded state, and the first diameter and the second diameter are each larger than the body diameter when the device is in an expanded state.
  • the device is configured to radially expand the first flanged section to engage with a first side of an atrial septum and configured to radially expand the second flanged section to engage with a second side of the atrial septum.
  • the RF energy source comprises at least one electrode configured for delivery of RF energy to the inner surface of the atrial septal channel.
  • the RF energy source is configured to deliver the RF energy for a predetermined time period or until a sensed parameter reaches a predetermined threshold.
  • the RF energy source is configured to deliver the RF energy via a monopolar delivery modality or a bipolar energy delivery modality.
  • the RF energy source comprises a plurality of electrodes configured to deliver the RF energy.
  • the plurality of electrodes comprises a first electrode having a first longitudinal length and a second electrode having a second longitudinal length, and the first electrode is interleaved with the second electrode to overlap the first longitudinal length with the second longitudinal length around a circumference of the cylindrical body section.
  • the device comprises an expandable balloon, the expandable balloon forms the first flanged section and the second flanged section, and the cylindrical body section comprises a sleeve member having a curved inner surface coupled to a curved outer surface of the expandable balloon.
  • the device comprises a self-expanding stent having the cylindrical body section, the first flanged section, and the second flanged section.
  • the device comprises a slotted tube expansion mechanism having the cylindrical body section, the first flanged section, and the second flanged section.
  • a method for expansion of an atrial septal channel comprises disposing a device comprising a radiofrequency (RF) energy source in the atrial septal channel.
  • the method further includes expanding the device to position the RF energy source in contact with an inner surface of the atrial septal channel expanded by the device, position a first flanged section of the device on a first side of the atrial septal channel, and position a second flanged section of the device on a second side of the atrial septal channel.
  • the method includes applying RF energy from the RF energy source to the inner surface to denature tissue of the atrial septal channel, erase tissue memory, and reduce tissue recoil.
  • applying the RF energy comprises activating the RF energy source for a predetermined time period. In certain embodiments, applying the RF energy comprises activating the RF energy source for one or more respective predetermined time periods during a predetermined number of activation cycles. In certain embodiments, applying the RF energy comprises activating the RF energy source until a sensed parameter reaches a predetermined threshold, and the sensed parameter comprises a temperature, an electrical impedance, a radial tissue force, or a radial tissue pressure.
  • the device comprises a cylindrical body portion having a body diameter positioned longitudinally between the first flanged section and the second flanged section, and expanding the device comprises increasing a first diameter of the first flanged section and increasing a second diameter of the second flanged section relative to the body diameter.
  • the device comprises an expandable balloon and a sleeve disposed around the expandable balloon to enable selective expansion of the first flanged section and the second flanged section.
  • the sleeve comprises the RF energy source.
  • the device comprises a self-expanding stent or a slotted tube expansion mechanism.
  • the self-expanding stent or the slotted tube expansion mechanism comprises a metallic material configured to direct the RF energy to the tissue of the atrial septal channel, and the metallic material comprises the RF energy source.
  • the RF energy source comprises a plurality of electrodes having a linear configuration, a nonlinear interleaved configuration, or a curvilinear interleaved configuration to deliver the RF energy via a bipolar energy delivery modality.
  • disposing the device in the atrial septal channel comprises delivering the device via a cannula, a catheter, or a delivery tube.
  • the method further comprising puncturing an atrial septum with a needle before disposing the device in the atrial septal channel.
  • a self-expanding stent for expansion of an atrial septal channel includes a cylindrical body section having a body diameter, a first flanged section extending from a first end of the cylindrical body section and having a first diameter, and a second flanged section extending from a second end of the cylindrical body section and having a second diameter.
  • the first diameter, the second diameter, and the body diameter are approximately equal when the stent is in an unexpanded state.
  • the first diameter and the second diameter are each larger than the body diameter when the stent is in an expanded state and positioned within the atrial septal channel.
  • the stent in the expanded state is configured to engage the first flanged section with a first side of an atrial septum and configured to engage the second flanged section with a second side of the atrial septum.
  • the self-expanding stent comprises an RF energy source comprising one or more electrodes configured to apply RF energy to an inner surface of the atrial septal channel to denature tissue thereof.
  • the RF energy source is configured to deliver the RF energy for a predetermined time period or until a sensed parameter reaches a predetermined threshold.
  • the RF energy source is configured to deliver the RF energy via a monopolar delivery modality or a bipolar energy delivery modality.
  • the RF energy source comprises a plurality of electrodes configured to deliver the RF energy.
  • Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods.
  • the foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood.
  • the various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.
  • FIG. 1A is a schematic view of an embodiment of a device delivery tube disposed across the atrial septum.
  • FIG. 1 B is a schematic view of an embodiment of balloon septoplasty, illustrating how deployment and removal of a balloon across the atrial septum leads to tissue of the septum recoiling to a reduced size.
  • FIG. 1C is a schematic view of an embodiment of a self-expanding stent according to one or more embodiments disclosed herein, illustrated as being partially deployed at the distal flange and also illustrated as fully deployed within an atrial septal channel.
  • Fig. 1 D is a schematic view of an embodiment of a radiofrequency (RF) energy balloon device according to one or more embodiments disclosed herein, illustrated as disposed across the atrial septum and also illustrated as disposed with respect to a denatured tissue (e.g., septum) so as to mitigate tissue recoil in the resulting channel.
  • RF radiofrequency
  • FIG. 2 is a schematic view of an embodiment of a method of preparing a selfexpanding stent according to one or more embodiments disclosed herein.
  • Fig. 3A is an axial micrograph of a self-expanding flanged stent according to one or more embodiments disclosed herein.
  • Fig. 3B is a transverse micrograph of a flanged stent according to one or more embodiments disclosed herein.
  • Fig. 3C is a representation of a flanged stent deployed across an atrial septum analogue.
  • Fig. 3D is an axial representation of a deployed flanged stent illustrating the maintenance of an enlarged opening or channel in the atrial septum analogue.
  • Fig. 4A is a slotted tube expansion mechanism according to one or more embodiments disclosed herein, shown in an initial configuration suited for positioning through an opening in the atrial septum.
  • the patterned segments indicate a possible bipolar electrode configuration with striped and filled portions representing electrically separate electrodes.
  • Fig. 4B is the slotted tube expansion mechanism of Fig. 4A illustrated in a shortened and expanded configuration.
  • Fig. 5A is a representation of a RF energy balloon device according to one or more embodiments disclosed herein, particularly, utilizing an unwrapped interleaved electrode array.
  • Fig. 5B is a schematic view of an electrode configuration for the RF energy balloon device.
  • Fig. 5C is a representation of a channel created and enlarged in the atrial septum analogue via an RF energy balloon device according to one or more embodiments disclosed herein.
  • Fig. 5D is an axial representation of a channel created in the atrial septum analogue without the application of RF energy from an RF energy balloon device as disclosed herein, illustrating a high degree of tissue recoil.
  • Figs. 6A, 6B, and 6C represent various embodiments of electrode configurations according to one or more embodiments disclosed herein, with different shades representing electrically separate electrodes.
  • Figs. 7 A, 7B, and 7C illustrate a hinged balloon device having a balloon body integrated with constricting electrodes according to one or more embodiments disclosed herein.
  • Figs. 8A, 8B, 8C, 8D, 8E, and 8F represent embodiments of interleaved electrode configurations according to one or more embodiments disclosed herein, with four examples of pediatric-sized configurations followed by two examples of adult-sized configurations.
  • FIGs. 9A and 9B are schematic views of an embodiment of an expandable stent according to one or more embodiments disclosed herein, illustrated in an unexpanded configuration and in an expanded configuration.
  • Fig. 10 is a representation of an embodiment of a method of preparing an expandable stent having a pattern laser cut onto a tubular member according to one or more embodiments disclosed herein.
  • Fig. 11 is a representation of the expandable stent of Fig. 10 that is fitted with a meshed sleeve between two flanged sections according to one or more embodiments disclosed herein.
  • Fig. 12 is a representation of another embodiment of a method of preparing an expandable stent by rolling and shortening a patterned sheet according to one or more embodiments disclosed herein.
  • Fig. 13 is a representation of another embodiment of a method of preparing an expandable stent by rolling and shortening a patterned sheet according to one or more embodiments disclosed herein.
  • FIGs. 14A, 14B, 14C, 14D, 14E, 14F, and 14G illustrate certain aspects of a method of an atrial septum enlargement surgery, such as a fetal surgery for treating hypoplastic left heart syndrome (HLHS) with restrictive atrial septum (RS) according to one or more embodiments disclosed herein.
  • HLHS hypoplastic left heart syndrome
  • RS restrictive atrial septum
  • Figs. 15A, 15B, 15C, and 15D illustrate some non-limiting variations of a surgical method for using an atrial septal channel device according to one or more embodiments disclosed herein.
  • Fig. 16 is a comparative bar chart illustrating an equivalent circular diameter of channels formed by six tested atrial septal channel devices, indicating the increased channel size produced in response to application of RF energy according to one or more embodiments disclosed herein.
  • FIGs. 17A, 17B, and 17C illustrate a representative pediatric-sized atrial septal channel device and the open area of a channel produced without and subsequently with the application of RF energy from the atrial septal channel device according to one or more embodiments disclosed herein.
  • FIGs. 18A, 18B, and 180 illustrate a representative adult-sized atrial septal channel device and the open area of a channel produced without and subsequently with the application of RF energy from the atrial septal channel device according to one or more embodiments disclosed herein.
  • FIGs. 19A and 19B show images of an opening formed through atrial septal tissue before and after application of RF energy from a pediatric-sized atrial septal channel device according to one or more embodiments disclosed herein.
  • FIGs. 20A and 20B show images of an opening formed through atrial septal tissue before and after application of RF energy from an adult-sized atrial septal channel device according to one or more embodiments disclosed herein.
  • the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to....”
  • the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections.
  • the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., the central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.
  • an atrial septal channel device for example, an atrial septal channel creation device and/or and atrial septal channel enlargement device, utilized interchangeably herein unless otherwise specified or dictated by context.
  • the atrial septal channel device facilitates the specialized enlargement of a small opening defined through the atrial septum, such as an insufficiently sized existing opening or an opening created prior to use of the atrial septal channel device.
  • Some embodiments of the atrial septal channel device may also provide for the creation of a relatively small opening or channel that is immediately expanded via the techniques disclosed herein, such as during a shared surgical procedure.
  • the atrial septal channel device may employ one or more of multiple expansion mechanisms generally configured to transform the atrial septal channel device from an unexpanded configuration to an expanded configuration within the opening, which causes the opening to enlarge into a suitably sized atrial septal channel.
  • the atrial septal channel device may be configured to be deployed within the heart of a patient or subject via a minimally invasive procedure (through endovascular routes, or alternatively through a chest port for access) such as through a small-bore catheter or a hollow needle.
  • the catheter or needle has a diameter of from about 0.5 millimeters (mm) to about 6 mm and is positioned using ultrasound guidance.
  • the atrial septal channel device may be expanded to mechanically create, define, and/or enlarge an opening in the atrial septum, for example, so as to establish a stable opening of at least 3 mm, or from about 3 mm to about 15 mm, in the atrial septum.
  • At least a portion of the atrial septal channel device positioned within the atrial septum may have an expanded diameter of from about 3 mm to about 19 mm, or from about 4 mm to about 10 mm, or from about 5 mm to about 9 mm, or from about 6 mm to about 8 mm.
  • the atrial septal channel device may be configured to deliver radiofrequency (RF) energy, via a suitable waveform algorithm configured to direct energy to one electrode or a plurality of electrodes incorporated into the atrial septal channel device, to denature (e.g., ablate or degrade), for example, thermally, the tissue around (e.g., substantially proximate to a periphery of) the opening so as to reset a zero stress state of the tissue (e.g., erase the tissue memory), thus preventing closure of the opening and/or to further expand the opening.
  • RF radiofrequency
  • the atrial septal channel device may comprise one or more electrodes disposed on or integrated within the atrial septal channel device and configured to provide targeted RF energy application directly to the tissue around the opening.
  • the application of RF energy to septal tissue disclosed herein provides significant benefits, including reduced or negligible tissue recoil relative to a comparative procedure that lacks RF energy usage.
  • the atrial septal channel devices that utilize RF energy may efficiently erase or reduce the tissue memory or elasticity that causes tissue recoil, enabling an established channel to remain open at a size that generally corresponds to the size of a septum-contacting portion of the atrial septal channel device. In some embodiments, this correlation enables practitioners to accurately and reliably produce enduring channels of a desired target diameter within an atrial septum based on the simple selection of the diameter of the utilized device.
  • the application of RF energy may be omitted, such as in certain embodiments in which the atrial septal channel device comprises an expandable stent that is installed within the atrial septal channel.
  • the self-expanding stent may be removed during a subsequent procedure, such as a particular growth milestone for a pediatric subject.
  • the atrial septal channel device may be suitably employed for treating conditions in pediatric subjects, adult subjects, or both.
  • the atrial septal channel device may have applications in fetal surgery in conditions such as HLHS with l/RAS, as well in adult heart failure where left atrial decompression is desired.
  • the atrial septal channel device may be delivered through a small-bore catheter or hollow needle around 0.5-2 mm in diameter and the atrial septal channel device may create an opening around 3-7 mm in diameter.
  • Adult applications may tolerate larger atrial septal channel devices that may be delivered through a larger catheter (up to 8 mm in diameter) and may create a larger opening (up to 15 mm in diameter). In either case, use of this small-sized catheter or needle for device deployment avoids issues with bleeding and/or loose tissue associated with potential alternative procedures such as a circle cutter, while simultaneously enhancing the creation of suitably sized atrial septal channels.
  • the atrial septal channel device may be configured to apply the RF energy at a preselected frequency or range of frequencies.
  • the atrial septal channel device may apply RF energy to the tissue surrounding the opening for a predetermined time period, such as an amount of time determined based on the age, weight, or other parameters (e.g., septum thickness) associated with the subject.
  • the atrial septal channel device applies the RF energy in a closed control loop. For example, application of the RF energy may be halted in response to the septal tissue reaching an upper temperature threshold.
  • the upper temperature threshold may be a critical transition temperature that causes the tissue to scar or immobilize and thus reduce recoil.
  • a temperature of the tissue is maintained below the boiling point of water. In some embodiments, the temperature of the tissue is closely monitored during device use to prevent or reduce any searing, charring, or overheating of the septal tissue. An operator of the atrial septal channel device may additionally or alternatively observe or detect a color change in the tissue and halt the RF energy application in response to the change.
  • the RF energy may be delivered via one or more suitably-configured electrodes.
  • the atrial septal channel device may include a specifically-tailored arrangement of electrodes, as disclosed herein.
  • the atrial septal channel device may utilize a monopolar electrode arrangement that directs energy through the subject and to a grounding component, such as an external grounding component positioned on the chest of a subject.
  • a grounding component such as an external grounding component positioned on the chest of a subject.
  • Certain monopolar electrodes may be particularly suitable for adult subjects, for example, based on their body mass.
  • the atrial septal channel device includes a bipolar or dipolar electrode modality or arrangement, in which a first electrode is separated from an oppositely charged second electrode by a specific spacing or gap, which may be correlated to a target rate of tissue heating.
  • the electrodes may enable the simultaneous or concurrent performance of tissue treatment and monitoring of the treatment.
  • the electrodes may provide real-time feedback regarding the electrical impedance or temperature of tissue in contact with the atrial septal channel device.
  • the atrial septal channel device monitors any suitable sensed parameter or variable from which a state or status of the tissue can be determined.
  • the sensed parameter includes a temperature, an electrical impedance, a radial tissue force, and/or a radial tissue pressure.
  • the atrial septal channel device may comprise and/or be associated with a suitably-configured controller.
  • the controller may be configured to deliver to the one or more electrodes a signal configured to yield the RF energy. Additionally or alternatively, the controller may be configured to receive one or more signals from the one or more electrodes indicative of a parameter associated with the tissue being treated, as disclosed herein.
  • the controller may comprise a microcontroller or microprocessors, suitable memory, and wireless communications modules (e.g., microchips or circuits), for example, suitable for communication via a desired communication interface.
  • the controller may comprise one or more integrated circuits comprising a suitable arrangement of transistors, LEDs, copper wires, tin-lead solder, ethylene tetrafluoroethylene (EFTE) coatings, or combinations thereof.
  • EFTE ethylene tetrafluoroethylene
  • the controller may be configured to carry out a desired functionality.
  • the controller may execute instructions stored in memory.
  • the memory can include computer system readable media in the form of volatile memory, such as random-access memory (RAM) and/or cache memory.
  • RAM random-access memory
  • the memory may further include other removable/non-removable, volatile/non-volatile computer system storage media.
  • the memory may include at least one application configured to carry out the disclosed functionalities, for example, evaluation of a signal and/or communication with an external device.
  • an application may be stored in the memory and may include a set of application program modules (e.g. software).
  • the application may also include an operating system and program data.
  • the application program modules may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
  • ISA instruction-set-architecture
  • machine instructions machine dependent instructions
  • microcode firmware instructions
  • state-setting data or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
  • the controller may be configured for communication with an external device such as a mobile device (e.g., a smart-phone), a tablet, or a computer.
  • the controller may comprise one or more communication modules configured to provide communication via wireless connection such as RF signals (Bluetooth, Wi-Fi, for example), inductive coupling, optical signaling, acoustic signaling, conducted communication signals, and/or any other signals suitable for communication.
  • the external device or controller may comprise a user interface that allows a user to control and monitor the operation of the atrial septal channel device via the communication over the wireless connection.
  • the user interface may comprise a graphical user interface (GUI) that is displayed on a mobile device, a tablet, a computer, or the controller.
  • GUI graphical user interface
  • the user interface may be modifiable to meet the needs of different users or medical professionals.
  • the user interface may include different languages or font sizes to accommodate users with different backgrounds or visual impairments.
  • the user interface may also include different modes or profiles for different types of functions or different users.
  • the user interface may also include security features, such as passwords or biometric authentication, to ensure that only authorized users can access the atrial septal channel device.
  • the user interface may allow a user to monitor the atrial septal channel device, to adjust settings, and to view realtime data from the atrial septal channel device.
  • the user interface may also provide alerts or notifications when the atrial septal channel device requires attention, such as a low battery alarm, or when certain conditions are met, such as when a treatment has concluded.
  • the controller may be configured to cause an electrical signal be generated and delivered to one or more electrodes so as to cause the RF energy to be applied to the cardiac tissue.
  • a plurality of electrical leads may be connected between the controller and the atrial septal channel device, for example, to provide a route of electrical communication between the controller and each of the one or more electrodes.
  • the electrical leads may comprise or be made from a suitable signal-conducting material, for example, gold, platinum, copper, or any suitable alloys thereof.
  • the material of the electrical leads includes MP-35N and/or MP-35N with titanium, platinum, or platinum-iridium alloys.
  • the atrial septal channel device may be characterized as self-positioning.
  • the atrial septal channel device may be configured such that, when positioned in the atrial septum, the atrial septal channel device exhibits a tendency to remain disposed in a desired position, for example, as originally deployed.
  • the atrial septal channel device may include at least one hinged or flanged end coupled to a middle body portion, such that the flanged end facilitates the targeted positioning of the atrial septal channel device within an opening defined through the atrial septum.
  • the atrial septal channel device may include one or two flanged sections or ends that radially expand when deployed to engage with respective sides of the atrial septum.
  • a surgeon may easily position the atrial septal channel device and activate an RF energy source thereof to selectively denature tissue and establish an enlarged atrial septal channel, which facilitates the proper, individualized blood circulation for any pediatric or adult subject.
  • the atrial septal channel device is configured as stent, for example, a self-expanding stent which may have flanged ends.
  • the self-expanding stent may be configured such that, when deployed, the self-expanding stent exhibits a tendency to expand in diameter, for example, in a direction perpendicularto its longitudinal axis (e.g., perpendicular to a lumen generally defined by the self-expanding stent).
  • the self-expanding stent may be formed from a metallic material or polymeric material.
  • the self-expanding stent may be formed from a shape-memory, superelastic alloy (e.g., Nitinol or an alloy such as 316 stainless steel) and/or a shape-memory polymer (including but not limited to polyorthoesters-lactide glycolides, caprolactones, and polyurethanes).
  • a shape-memory, superelastic alloy e.g., Nitinol or an alloy such as 316 stainless steel
  • a shape-memory polymer including but not limited to polyorthoesters-lactide glycolides, caprolactones, and polyurethanes.
  • the flanged, self-expanding stent may comprise or be formed from polymers including, but not limited to, polypropylene, polytetrahydroxybutyrate, polytetrafluoroethylene, polyethylene, and combinations thereof.
  • the self-expanding stent may also include one or two flanges that serve to locate the tissue over the electrodes described above. When deployed and upon delivery, the flanges may aid in device positioning and may be effective to minimize device migration.
  • the self-expanding stent may be configured to deliver RF energy.
  • the self-expanding stent may comprise electrodes bonded to the stent or may use the stent itself as the electrode in the case of a metallic stent.
  • the stent may be comprised of multiple rings which may each serve as separate electrodes.
  • the selfexpanding stent may be configured having a monopolar or a bipolar energy delivery modality and may employ similar energy control mechanisms as described herein with respect to various other embodiments.
  • the self-expanding stent may be partially ejected to deploy the distal flange.
  • the cannula may then be withdrawn until the flange is observed to contact the atrial septum via ultrasound visualization.
  • the selfexpanding stent With the distal flange in position, the selfexpanding stent is fully ejected while withdrawing the cannula.
  • the self-expanding stent now unconstrained, opens to its full diameter and creates or expands the atrial septal opening into a suitably sized channel.
  • the atrial septal channel device has several advantages over the currently used coronary stents.
  • the distal flange allows for a degree of self-location during stent placement, ameliorating otherwise challenging conditions for device visualization and positioning.
  • the atrial septal channel device is much shorter than a coronary stent which minimizes the chances of contact with the walls of the atria.
  • the flanges prevent stent migration while the atrial septum moves with each heartbeat.
  • the stent is designed to remain in position within a pediatric subject and later removed, for example, until performance of a Norwood procedure, where the self-expanding stent is removed during the atrial septectomy.
  • a selfexpanding stent may be made larger than a balloon expanded one, which may aid in the creation of a larger septal defect and thus lead to better decompression of the left atrium.
  • the atrial septal channel device comprises a mechanically expandable slotted tube, as illustrated in Fig. 4A, that may be shortened to cause the slotted section to expand, as illustrated in Fig. 4B.
  • the expanded configuration forms flanges that locate the tissue over the electrodes.
  • the expander may be fabricated from a metallic or polymeric tube, for example, as otherwise disclosed herein, and shape-set to bias the expanded configuration in the desired flanged shape.
  • the shortening may be achieved via application of a linear or helical motion.
  • a similar expansion mechanism may also be achieved using a helical braided tube instead of a slotted one, in certain embodiments.
  • electrodes may be bonded to the tines of the expander.
  • This embodiment may also use monopolar or bipolar energy delivery modalities and employ similar energy control mechanisms as described herein with respect to various other embodiments.
  • the atrial septal channel device comprises a single or double flanged balloon, which may share certain similarities to the currently used septostomy balloons, to expand and/or create the atrial septal defect.
  • the balloon may comprise one or two flanges.
  • the flanged balloon similar to the stent, self-locates, which eases the burden of skill for a surgeon.
  • the balloon may be made of a non- compliant, semi-compliant, or elastic material.
  • the balloon may be formed from a polyurethane, nylon, silicone, and/or polyethylene material.
  • the balloon may include an electrode array bonded to its surface that may be used to deliver RF energy (e.g., electrical energy, which heats tissue in its proximity).
  • RF energy e.g., electrical energy, which heats tissue in its proximity.
  • the balloon may be partially deployed and partially inflated.
  • the cannula is then withdrawn until the balloon flange is observed to contact the atrial septum on ultrasound visualization.
  • the balloon may then be fully deployed and inflated to open the atrial septal defect. With the flange in contact with the atrial septum, the electrode array is configured to be in contact with the septal tissue in this position.
  • RF energy may then be applied to the electrode array via an electrosurgery generator to cause heating and denaturation of the septal tissue, after which the balloon is deflated and withdrawn.
  • tissue denatured in the expanded state tissue recoil after balloon removal is minimized, thereby creating a larger channel in the atrial septum compared to traditional balloon septostomy, for example, as shown in Fig. 1 D.
  • the disclosed balloon-based approach leaves no foreign material in the heart.
  • the atrial septal channel device is configured to deliver the RF energy using a bipolar modality, for example, such that a substantial portion of the electrical current path is contained within the atrial septal channel device, minimizing potential risk to the patient.
  • the electrode array may be configured to use one of the two energy delivery modalities seen in electrosurgery: bipolar or monopolar.
  • bipolar electric current flows from one set of electrodes, through tissue and returns to another set of electrodes.
  • monopolar electric current flows from one set of electrodes, through tissue, and returns to an external grounding pad attached to the patient.
  • the bipolar modality may provide greater control over the complete current path, reducing risks to the patient.
  • a possible electrode array configuration is comprised of two interleaved electrode sets, as shown in Fig. 5A.
  • the number, spacing, and dimensions of the electrodes may be varied to optimize RF energy delivery and manage the spread of thermal energy.
  • the electrodes may be configured with a linear configuration, a nonlinear interleaved configuration, or a curvilinear interleaved configuration.
  • the electrode array may also be comprised of individually selectable electrodes, in which pairs of electrodes may be energized to deliver electrical energy to only the tissue between the selected electrodes.
  • Electrodes may be selected in a predetermined sequence, randomly, or in response to measured tissue conditions (e.g., impedance, temperature, and/or a radial tissue force or pressure applied by the septal tissue).
  • the atrial septal channel device may employ single large electrodes that run along the circumference of at least a portion of the atrial septal channel device, as illustrated in Fig. 6A.
  • the electrodes may be arranged on the balloon such that they contact opposite sides of the atrial septum. The width and spacing of the electrodes may be varied to optimize RF energy delivery.
  • the electrode pair may also be comprised of two waveforms such as a sinusoid/zigzag that run along the circumference of at least a portion of the atrial septal channel device, as illustrated in Fig. 6B.
  • the width, pitch, and amplitude of the waveforms may be varied to achieve a desired RF energy delivery.
  • the waveforms may be sinusoid, triangle, square, sawtooth or a superimposition of multiple waveforms with varying pitch, amplitude, and width.
  • the waveforms may also be generated by a mapping function.
  • the electrodes may also be comprised of polygonal or ellipsoid shapes along the circumference of at least a portion of the atrial septal channel device in linear or tiled arrangements, as shown in Fig. 6C. In some embodiments, electrodes may also be enclosed within other electrodes.
  • the array may be comprised of one or more rows of electrodes. The size, shape, number, and spacing of the shapes may be varied to achieve a desired RF energy delivery.
  • the electrode array may also be comprised of a combination of any of the previously described electrode configurations.
  • the two electrode sets seen in the bipolar version may be replaced by a singular electrode or electrode array.
  • the electrode array may cover a percentage of the circumference of the atrial septal channel device, for example, from 10% to 99.9%, or from about 20% to about 80%.
  • the width of the electrode array may be varied depending on the target atrial septum thickness and may range from 0.5 mm to 10 mm.
  • the thickness of the electrodes in the radial direction may be varied to optimize the resistance of the electrical traces and may range from 0.01 mm to 1 mm.
  • the array may also be asymmetric where a certain portion of the circumference may have variations in electrode dimensions/spacing or be devoid of electrodes to avoid damage to critical heart structures. In such cases, the atrial septal channel device would include radio-opaque or echogenic features on the expander or shaft that indicate device orientation.
  • RF energy may be varied to achieve tissue denaturation and control thermal spread.
  • Features under control may include voltage (100 V to 5000 V), power (0.1 W to 100 W), and frequency (50 kHz to 10 MHz). These features may also be temporally varied over the course of a single operation of the atrial septal channel device.
  • Features may be varied in response to measured tissue conditions (e.g., impedance or temperature), a predetermined sequence, or a combination thereof.
  • RF energy may be delivered for durations ranging from 0.05 seconds (s) to 120 s, additionally or alternatively, from 0.5 s to 20 s, additionally or alternatively, from 0.75 s to 10 s or, additionally or alternatively from 1 s to 5 s.
  • the duration may be predetermined or varied in response to measured tissue conditions, for example, on the basis of changes in impedance and/or temperature exhibited by the tissue.
  • the atrial septal channel device is activated in a sequence, such as for one or more respective predetermined time periods during a predetermined number of activation cycles.
  • the atrial septal channel device may apply RF energy for a first predetermined time period, halt the RF energy application, and apply RF energy again for a second predetermined time period. Any suitable number of activation cycles, each having a respective time duration suited for precise tissue denaturation, may be performed by embodiments herein.
  • the electrodes may be configured to hinge during the inflation of the balloon, for example, such that upon hinging the electrodes are brought into close contact with the atrial septum, as shown in Fig. 7A.
  • the hinging may also be achieved by using a balloon made of a compliant elastomeric material (e.g., silicone, polyurethane) with a sleeve or collar made of a non-compliant thermoplastic material (e.g., polyethylene terephthalate, nylon).
  • the sleeve is made of any suitable material having a greater rigidity and/or lower compliance than the remaining balloon material.
  • the sleeve of certain embodiments may be integrated with the balloon material, such as within a three-piece construction having a first balloon portion, which is connected to a middle sleeve portion, which is connected to a second balloon portion.
  • a first balloon portion which is connected to a middle sleeve portion
  • a second balloon portion which is connected to a second balloon portion.
  • the electrodes may be bonded to either the balloon or sleeve.
  • the balloon of the atrial septal channel device includes a curved outer surface that is coupled to a curved inner surface of a sleeve or sleeve member.
  • FIGS. 8A-8F Additional embodiments of interleaved, dipolar electrode arrangements suitable for use with an atrial septal channel device are shown in Figs. 8A-8F.
  • Figs. 8A-8D illustrate embodiments of interleaved electrode configurations sized for use within pediatric subjects.
  • Figs. 8E and 8F illustrate embodiments of interleaved electrode configurations sized for use within adult subjects.
  • These electrode configurations may be positioned to circumferentially surround the middle portion of an expandable balloon that is positioned in contact with an atrial septum, thereby blocking overexpansion in this area and providing for the localized delivery of RF energy for tissue denaturation.
  • a stent for use as an atrial septum channel enlargement device may be coupled with, or operates as, one or more electrodes that deliver RF energy to denature septal tissue and reduce recoil or shrinkage of the channel.
  • Any component, feature, or combination thereof disclosed with reference to the following stent may be employed with corresponding components and/or features of the self-expanding stent, slotted tube mechanism, and/or expandable balloon described above.
  • Embodiments disclosed herein include additional, non-limiting examples of devices suitable for use in creating an atrial septal channel.
  • these devices may be used with examples of RF energy delivering electrodes for denaturing tissue and reducing recoil.
  • the application of RF energy may be omitted, and the atrial septal channel devices may be retained within the atrial septal channel to physically maintain the channel at a desired diameter.
  • the atrial septal channel device is configured as a stent 100 that comprises a first expansion segment 101 (e.g., flanged section) at a first end of the stent 100; a second expansion segment 105 (e.g., flanged section) at a second end of the stent 100; and a middle expansion segment 103 (e.g., cylindrical body section) between the first expansion segment 101 and the second expansion segment 105.
  • a first expansion segment 101 e.g., flanged section
  • second expansion segment 105 e.g., flanged section
  • middle expansion segment 103 e.g., cylindrical body section
  • the stent herein has an n unexpanded state 100 and an expanded state 100’.
  • an unexpanded diameter of the first expansion segment 101 , an unexpanded diameter of the second expansion segment 105, and an unexpanded diameter of the middle expansion segment 103 are substantially the same or approximately equal to one another.
  • the diameters as recited in this document are those of the average diameter.
  • the diameter of an expansion segment is measured at a cross-sectional plane perpendicular to the longitudinal direction of the expansion segment where the expansion segment is the widest, and measured from the center to the outer surface of the expansion segment.
  • each of the first expansion segment 101’, the second expansion segment 105’, and the middle expansion segment 103’ expands in dimensions in the vertical and horizontal directions, but not in the longitudinal direction.
  • the expanded diameter of the first expansion segment 101’, and/or an expanded diameter of the second expansion segment 105’ are larger than an expanded diameter of the middle expansion segment 103’.
  • the expanded diameter of the first expansion segment 101’, and the expanded diameter of the second expansion segment 105’ are substantially the same. In some embodiments, in the expanded state of the stent 100’, the expanded diameter of the first expansion segment 101’ is larger or smaller than the expanded diameter of the second expansion segment 105’ for less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 10%, less than about 5%, or less than about 2%.
  • a ratio of the expanded diameter of the first expansion segment 101’, or the expanded diameter of the second expansion segment 105’ to the expanded diameter of the middle expansion segment 103’ is about 1.5:1 or more, about 2:1 or more, about 2.5 or more, about 3:1 or more, or about 4:1 or more. In some embodiments, a ratio of the expanded diameter of the first expansion segment 101’, or the expanded diameter of the second expansion segment 105’ to the expanded diameter of the middle expansion segment 103’ is about 10:1 or less, about 9:1 or less, about 8:1 or less, about 7:1 or less, about 6:1 or less, or about 5:1 or less.
  • a ratio of the expanded diameter of the first expansion segment 101’, or the expanded diameter of the second expansion segment 105’ to the expanded diameter of the middle expansion segment 103’ is about 1.5:1 , about 2:1 , about 2.5:1 , about 3:1 , about 4:1 , about 5:1 , about 6:1 , about 7:1 , about 8:1 , about 9: 1 , about 10: 1 , or any ranges therebetween.
  • the stent may be characterized as having one or more of the following configurations: (A) the unexpanded diameter of first expansion segment, the second expansion segment, and the middle expansion segment ranges from about 0.7 mm to about 2 mm; (B) the ratio of the expanded diameter of the first expansion segment 101’, or the expanded diameter of the second expansion segment 105’ to the expanded diameter of the middle expansion segment 103’ ranges from about 1 .5:1 to about 5:1 ; (C) the expanded diameter the first expansion segment 101’, and/or the expanded diameter the second expansion segment 105’ ranges from about 6 mm to about 10 mm; and (D) the expanded diameter of the middle expansion segment 103’ ranges from about 2 mm to about 5 mm.
  • the stent 100 or 100’ further comprises a connector 107, 107’, 109, and/or 109’ at the first end or the second end thereof for attaching to a tip of a guide wire or a catheter.
  • the surgical operations using the stents herein sometimes require the removal or repositioning of the stent.
  • the connector simplifies the removal or repositioning of the stent from the patient.
  • the connector 107, 107’, 109, and/or 109’ comprises screw threads, such as male orfemale screw threads.
  • the stent is hollow along a longitudinal direction.
  • first expansion segment, the second expansion segment, and/or the middle expansion segment are self-expanding.
  • the first expansion segment, the second expansion segment, and/or the middle expansion segment are expanded by an inflatable balloon.
  • the stent is prepared by carving, laser cutting, or otherwise forming a predetermined pattern on a tubular member formed of stent material. (See e.g., Figs. 10, 12, and 13).
  • the stent is made from two or more pieces.
  • the stent further comprises a reinforcing element, such as a sleeve or a reinforcement mesh, that provides additional strength to the middle expansion segment, such that the middle expansion segment can hold the opening introduced to a tissue at a desirable diameter without being compressed by the tissues surrounding the opening.
  • a reinforcing element such as a sleeve or a reinforcement mesh
  • the stent is made from at least one material selected from the group consisting of stainless steel, a cobalt chromium alloy, a nickel-titanium alloy, platinum, a tantalum alloy.
  • the present disclosure is directed to a method of introducing and maintaining an opening in a tissue.
  • the method comprises puncturing the tissue to form the opening; sending a stent across the tissue and expanding the stent; and keeping the opening open with the stent.
  • the first expansion segment of the stent when the opening is being held by the stent: the first expansion segment of the stent is on a first side of the tissue, the second expansion segment of the stent is on a second side of the tissue, and the middle expansion segment of the stent holds the opening at a predetermined size.
  • sending the stent across the tissue and expanding the stent comprises: sliding the unexpanded first expansion segment across the opening; expanding the first expansion segment on the first side of the tissue; expanding the middle expansion segment inside the opening; and expanding the second expansion segment on the second side of the tissue.
  • RF energy may be delivered to the tissue surrounding the atrial septal channel device, for example, via one or more electrodes disposed on the electrodes.
  • the present disclosure is directed to a method of treating, ameliorating, and/or preventing hypoplastic left heart syndrome (HLHS) in a subject in need thereof.
  • the subject is a fetal subject in mother’s womb.
  • the HLHS is characterized in intact or restrictive atrial septum (RS).
  • the method comprises: puncturing the atrial septum in the fetal subject to form an opening; sending the stent across the atrial septum and expanding the stent; and keeping the opening open with the stent.
  • the first expansion segment of the stent is in the left atrium of the heart
  • the second expansion segment of the stent is in the right atrium of the heart
  • the middle expansion segment of the stent holds the opening at a predetermined size.
  • sending the stent across the atrial septum and expanding the stent comprises: sliding the unexpanded first expansion segment across the opening; expanding the first expansion segment in the left atrium; expanding the middle expansion segment inside the opening; and expanding the second expansion segment in the right atrium.
  • the unexpanded first expansion is delivered across the atrial septum using a catheter system.
  • the method further comprises removing the stent from the heart.
  • Figs. 14A-14G describe a method of treating fetal HLHS patient with l/RAS in accordance with some embodiments.
  • Fig. 14A in the fetal patient, the atrial septum between the left and right atria are restricted or intact.
  • Fig. 14B to treat the condition, a catheter shaft 200 is moved across the maternal abdominal wall, the uterine wall, the fetal chest wall, and the fetal heart wall until the tip of the catheter is in proximity to the fetal atrial septum.
  • a catheter needle 300 is moved forward along an interior of the catheter shaft, protruding out of the tip of the catheter shaft, and punctures the atrial septum. Referring to Fig.
  • a stent 400 is moved along the interior of the catheter shaft until the first expansion segment of the stent protrudes out of the tip of the catheter shaft, passes through the opening, and enters the left atrium.
  • the first expansion segment is expanded in the left atrium, such as by self-expansion.
  • the tip of the catheter shaft 200 is moved away from the opening, which gradually expose the middle expansion segment 405 and the second expansion segment 403 of the stent 400.
  • the middle expansion segment 405 and the second expansion segment 403 expands via self-expansion.
  • the middle expansion segment 405 holds the opening at a predetermined size, and the first and second expansion segments are expanded in the left and right atria, respectively, and restricts the movement of the stent 400.
  • the fully expanded stent 400 opens the fluid communication between the left atrium and the right atrium.
  • Figs. 15A, 15B, 15C, and 15D illustrate a non-limiting example of this surgical procedure implemented with the atrial septal channel devices described above.
  • a second surgical operation can be performed to remove the stent, which may allow the opening to close, as the heart development requires.
  • the second surgical operation may be performed after the baby is born, removing the stent along with the atrial septum as part of the Norwood procedure, for example.
  • An atrial septum analogue is formed from the fusion or adhesion of the septum primum and septum secundum and is primarily comprised of myocardium. While limited data exists on the thickness of the atrial septum in HLHS with IAS, a 1 mm septal thickness was chosen to represent a “thick” atrial septum for this study.
  • Porcine heart (Animal Technologies Inc., Tyler, TX) was selected as a source of cardiac tissue on account of its ready availability.
  • a Leica VT1000 S vibrating blade microtome (Leica Biosystems, Deer Park, IL) was used to create 1 mm thick slices of cardiac tissue from the ventricular walls of the porcine heart. The tissue slices were equilibrated in phosphate buffered saline (PBS) at 37°C for at least 15 minutes prior to device testing.
  • PBS phosphate buffered saline
  • An embodiment of a balloon device is envisioned to first dilate an opening in the atrial septum and then apply RF energy to mitigate tissue recoil.
  • a 3.5 mm diameter mandrel with a 10° dilating tip was stereolithography 3D printed on the Formlabs Form 3B, commercially available from Formlabs in Somerville, Massachusetts using the Formlabs clear resin.
  • An electrode array comprised of two interleaved electrode sets with three electrodes each, as shown in Fig. 5B, was cut from 25 micrometer (pm) thick stainless steel foil.
  • Electrodes made from 38 gauge copper wire were soldered to each electrode set.
  • the electrodes were bonded to adhesive tape at the upper and lower ends which was used to attach the array to the 3D printed mandrel.
  • the wire leads were connected to the bipolar output of a Bovie 1250S electrosurgery generator, commercially available from Symmetry Surgical Inc. in Nashville, Tennessee. [00118]
  • the dilating tip of the test device was used to penetrate the atrial septal analogue, simulating the expansion of the balloon.
  • the electrode array was then positioned across the atrial septum and the electrosurgery generator was activated at 20W for 3 seconds, denaturing the tissue.
  • the electrode was then removed, and the tissue was photographed with a ruler in the plane of the tissue to measure the size of the created and enlarged opening, as shown Fig. 5C.
  • the experiment was repeated on a second septal analogue without activation of the electrode array to evaluate the level of recoil that was prevented, as shown in Fig. 5D.
  • the area of the opening created in each case was measured and the equivalent circle diameter was calculated.
  • the balloon device simulator successfully enlarged a channel in the atrial septum analogue.
  • the 3.5 mm device enlarged an opening to an effective circle diameter of 3.1 mm, which compares favorably to other stented channels.
  • the resultant channel had an effective diameter of only 1.2 mm indicating significant tissue recoil akin to that seen in balloon atrial septostomy and validating the value of ablation or denaturation of the tissue adjacent to the surface electrodes.
  • the heat affected zone created by the atrial septal channel device needs to be tightly controlled in consideration of the potential risk to the conductive apparatus of the heart from the proximity of the target zone to the atrioventricular (AV) node.
  • the atrial septal channel device aims to use an electrode array without multiplexed control of the energy delivery to the electrodes.
  • tissue impedance rises as the denaturation process progresses which will likely lead to a natural balancing of the energy delivery away from regions where the denaturation has advanced further.
  • This study used a fixed RF energy delivery time, but the delivery time may be adjusted in actual use, such as based on the treated individual and/or within a closed control loop, given the large variability in atrial septal thickness and hence the volume of tissue that needs to be denatured. This may be achieved through monitoring of the net impedance through the atrial septal channel device to determine the procedure endpoint. Additionally or alternatively, temperature sensors may be incorporated to directly measure tissue temperatures.
  • the adjustable energy delivery would also likely allow for greater consistency in the size of the atrial septal channel across a range of septum thicknesses compared to a purely mechanical stenting approach.
  • a limitation of this approach stems from the proximity of the atrioventricular node to the procedure site. There is a risk of damage to the conductive apparatus of the heart when using this device and as such, the energy delivery and thermal spread will need to be carefully controlled to minimize this risk. While this feasibility test was conducted with air as the surrounding medium, given the influence of heat transfer on the performance of this device, a temperature controlled, flowing fluid test bed will be required to more accurately evaluate device function.
  • a flanged, self-expanding stent as disclosed herein, formed from nitinol was fabricated using a commercially available self-expanding carotid stent, the 5 x 20 mm Cordis PRECISE® PRO Rx Nitinol Stent System (Cordis, Miami Lakes, FL). Three stent ring segments were cut from the atrial septal channel device by ablating the connecting links between stent segments using a laser welder (Laserstar iWeld 100 Joule, LaserStar Technologies Corporation, Orlando, FL).
  • the three-ring stent was then mounted on a stainless steel mandrel and compressed between two polished stainless steel plates to splay the proximal and distal ends (e.g., rings) outwards.
  • Stainless steel wire was used to tie down or circumferentially restrict the central ring to ensure that the bending occurred at the inter-segment links.
  • This assembly was then placed in a 550°C furnace for 5 minutes to shape-set the stent in the new flanged design configuration before water quenching, as shown in Fig. 2.
  • the stent was imaged in the axial and transverse direction, as illustrated in Figs. 3A and 3B, respectively.
  • the stent was then radially crimped and transferred into a 16-gauge stainless steel delivery tube.
  • the 16-gauge tube was used to avoid excessive plastic deformation during the loading process given that this particular embodiment of the stent was not designed for delivery through an 18-gauge cannula.
  • a 16-gauge pointed obturator was used to place the loaded delivery tube across the atrial septum analogue.
  • An 18-gauge stainless steel tube was used as a pusher to partially eject the atrial septal channel device until the distal flange was fully deployed, as illustrated in Fig. 3C.
  • the delivery tube was retracted until the flange was in contact with the tissue.
  • the stent was then fully ejected while withdrawing the delivery tube across the tissue, completing the atrial septal channel device deployment.
  • the stent was photographed axially with a ruler in-plane with the stent to measure the diameter of the opening established in the atrial septum analogue, as shown in Fig. 3D.
  • the flanged, self-expanding stent was able to be deployed successfully and it was observed that the flange was effective to cause the stent to maintain contact with the tissue, reducing the degree of precision required in the positioning of the delivery tube.
  • the stent created a 1 .7 mm diameter opening in the atrial septum. After removing the stent from the tissue, the free-expanded inner diameter of the stent was measured at 2.4 mm which is lower than the initial 4.2 mm inner diameter indicating deformation beyond the yield point of the material during crimping and loading.
  • a flanged, self-expanding stent as disclosed herein may be used to create and enlarge or maintain an opening in the atrial septum. While the resultant channel was significantly smaller than the 2.5-3.5 mm diameter channels created in other atrial stenting efforts, the off-the-shelf stent used here had a free expanded diameter of only 2.4 mm. A stent engineered specifically for this application may be able to achieve significantly greater expanded diameters.
  • One of the limitations of this approach is the need to accommodate the large variability in the thickness of the atrial septum across patients. This could impact the size of the channel produced by the atrial septal channel device on account of greater mechanical resistance to the selfexpansion with thicker septa.
  • the design will need to carefully control the maximum strain to avoid plastic deformation when crimped to the small diameters needed.
  • the stent material is nitinol, which exhibits superelastic characteristics
  • tooling and manufacturing process controls may be optimized during the cold working and heat treatment/shape setting steps to ensure minimal excursions in the Af (Austenite finish temperature).
  • Af Austenite finish temperature
  • the flanged stent has secondary bend points between the flanged and straight sections which may be further optimized.
  • the stent may also be optimized with respect to the stent geometric features to achieve the desired superelastic response, such as via finite element analysis during the detailed design of the stent to quantify the strains in these regions.
  • Embodiments of atrial septal channel devices were constructed and tested to assess the effectiveness of the atrial septal channel device for selectively denaturing atrial septal tissue with RF energy to establish channels or through-holes of increased sizes.
  • the tests aimed to demonstrate the performance of the atrial septal channel device based on measuring the difference in the size of an enlarged channel created with use of RF energy to minimize tissue recoil, as compared to channels created without the use of RF energy.
  • the atrial septal channel devices were tested on the prepared atrial septum analogue derived from porcine cardiac tissue slices.
  • Atrial septal channel devices were prepared, each including a respective bipolar electrode configuration or array.
  • the electrode configurations were prepared, fabricated as flexible printed circuit boards, and bonded to non-compliant dilation balloon catheters.
  • the balloon dilation catheters were Hurricane RX Biliary Balloon Dilation Catheters, commercially available from Boston Scientific in Marlborough, Massachusetts.
  • Four of the configurations were designed for a 4 mm balloon dilation catheter, corresponding to a pediatric balloon size, and the two of the configurations were designed for a 10 mm balloon dilation catheter, corresponding to an adult balloon size.
  • These electrode configurations are shown in Figs.
  • the experiments employed an 18-gauge chiba needle to create an initial puncture in the tissue and guide the atrial septal channel device across the puncture formed through the tissue.
  • the balloon of the atrial septal channel device was then inflated with water to a target pressure of 6 atmospheres, held at this pressure for 10 seconds, and then deflated.
  • the tissue was then imaged under a microscope to measure the area of the opening created in the tissue, without the application of RF delivery. Following this measurement, the balloon was reinserted through the channel, aligning the tissue with the electrodes of the atrial septal channel device.
  • the electrodes were then energized to denature the tissue around the channel. For pediatric sizes, the generator output was set to 5 W, and the energy was applied for 5 seconds.
  • the output was set to 10 W and applied for 10 seconds.
  • the balloon was deflated and the atrial septal channel device was withdrawn.
  • the area of the resultant channel was then measured under a microscope.
  • the areas of the channel, measured before and after application of RF energy, were converted to an equivalent circular diameter (ECD), representing the diameter of a circle that has the same area as the channel.
  • ECD equivalent circular diameter
  • tissue rebound of the septal analogues resulted in a channel with an average ECD of less than half the diameter of the balloon that was used to create it.
  • the average ECD of the channel for the two adult-sized experiments, labeled Adult 1 and Adult 2 was 4.08 mm when using the 10 mm balloon.
  • the average ECD of the channel for the four pediatric-sized experiments, labeled Pediatric 1 , 2, 3, and 4, was 1 .99 mm when using the 4 mm balloon.
  • Fig. 17A is a photograph of a representative, pediatric-sized atrial septal channel device used during these experiments.
  • Fig. 17B illustrates the channel formed by the device of Fig. 17A and its corresponding axes, DL0 and DL1 , used in determining the ECD when RF energy is not applied.
  • Fig. 17C illustrates the subsequent increase in the channel size when RF energy is applied, such as based on the RF energy denaturing the tissue and reducing recoil.
  • Fig. 18A is a photograph of a representative, adult-sized atrial septal channel device used during these experiments, and Figs. 18B and 18C illustrate the size of the channels produced by the device of Fig. 18A without RF energy applied and with RF energy applied, respectively.
  • the ECD of the channels more than doubled for the same sized balloons of the atrial septal channel devices.
  • the average ECD for the channel was 8.80 mm for the adult-sized experiments and was 4.33 mm for the pediatric-sized experiments.
  • Application of RF energy therefore resulted in a five-fold increase in the area of the channel available for blood flow across the atrial septum in both the adult and the pediatric sizes.

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Abstract

Des modes de réalisation de la présente invention comprennent un dispositif de canal pour septum auriculaire qui facilite la création et/ou l'agrandissement d'un canal à travers un septum auriculaire, ainsi que des méthodes et des systèmes d'utilisation de celui-ci dans le traitement d'un patient. Dans un mode de réalisation, un dispositif de canal pour septum auriculaire comprend une section de corps cylindrique doté d'une source d'énergie radiofréquence (RF), une première section à bride s'étendant à partir d'une première extrémité de la section de corps cylindrique et ayant un premier diamètre, et une seconde section à bride s'étendant à partir d'une seconde extrémité de la section de corps cylindrique et ayant un second diamètre. De plus, le dispositif est conçu pour se dilater à l'intérieur d'un canal de septum auriculaire pour augmenter le premier diamètre de la première section à bride, augmenter le second diamètre de la seconde section à bride, et positionner la source d'énergie RF en contact avec une surface interne du canal de septum auriculaire.
PCT/US2025/023713 2024-04-08 2025-04-08 Dispositif de canal pour septum auriculaire Pending WO2025217198A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130023873A1 (en) * 2005-04-21 2013-01-24 Asthmatx, Inc. Control methods and devices for energy delivery
US20200261704A1 (en) * 2017-10-31 2020-08-20 Hangzhou Naya Medtech Co., Ltd Devices, systems, and methods for interatrial shunts
US20210338990A1 (en) * 2020-05-04 2021-11-04 V-Wave Ltd. Devices with dimensions that can be reduced and increased in vivo, and methods of making and using the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130023873A1 (en) * 2005-04-21 2013-01-24 Asthmatx, Inc. Control methods and devices for energy delivery
US20200261704A1 (en) * 2017-10-31 2020-08-20 Hangzhou Naya Medtech Co., Ltd Devices, systems, and methods for interatrial shunts
US20210338990A1 (en) * 2020-05-04 2021-11-04 V-Wave Ltd. Devices with dimensions that can be reduced and increased in vivo, and methods of making and using the same

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