Devices for reducing left atrial pressure, and methods of making and using same
A device for regulating blood pressure between a patient's left atrium and right atrium comprises an hourglass-shaped stent comprising a neck region and first and second flared end regions, the neck region disposed between the first and second end regions and configured to engage the fossa ovalis of the patient's atrial septum; and a one-way tissue valve coupled to the first flared end region and configured to shunt blood from the left atrium to the right atrium when blood pressure in the left atrium exceeds blood pressure in the right atrium. The inventive devices may reduce left atrial pressure and left ventricular end diastolic pressure, and may increase cardiac output, increase ejection fraction, relieve pulmonary congestion, and lower pulmonary artery pressure, among other benefits. The inventive devices may be used, for example, to treat subjects having heart failure, pulmonary congestion, or myocardial infarction, among other pathologies.
1. A method of delivering a shunt to an atrial septum of a patient to reduce atrial pressure of the patient, the method comprising:
selecting an atrial shunt having first and second conical sections, each of the first and second conical sections having a flared end region, wherein apices of the first and second conical sections are joined together to form a neck region disposed in a mid-region of the atrial shunt, the atrial shunt defining a shunt lumen configured to shunt blood through the atrial septum to reduce atrial pressure;
selecting a sheath configured for transvascular insertion via the patient's blood vessel and a pusher configured to be disposed in a lumen of the sheath;
loading the atrial shunt into the sheath, wherein the first and second conical sections are compressed inward relative to a longitudinal axis of the shunt to a contracted position, and a proximal end of the second conical section is disposed in contact with the pusher;
percutaneously delivering the sheath through an opening formed in the atrial septum such that a distal region of the sheath is disposed within a left atrium;
advancing the pusher distally relative to the sheath to expose the first conical section so that it transitions from a compressed state to an expanded state within the left atrium;
retracting the shunt and the sheath proximally such that the first conical section engages the atrial septum from within the left atrium and the neck region engages the opening in the atrial septum, thereby enabling the shunt to self-locate in the opening; and
further retracting the sheath proximally such that the first conical section flanks the atrial septum from within the left atrium, the neck region is lodged in the opening formed in the atrial septum, and the second conical section is exposed from the sheath and transitions from a compressed state to an expanded state within the right atrium, thereby facilitating shunting of blood through the shunt lumen between the left atrium and the right atrium.
2. The method of claim 1 , further comprising mechanically locking the pusher such that further advancement of shunt within the lumen of the sheath is prevented.
3. The method of claim 1 , wherein percutaneously delivering comprises percutaneously delivering the sheath via a femoral vein access point.
4. The method of claim 1 , further comprising, prior to percutaneously delivering the sheath, percutaneously delivering at least one of a needle and a guidewire to the atrial septum and puncturing the atrial septum.
5. The method of claim 4 , wherein the sheath is delivered over the guidewire.
6. The method of claim 1 , further comprising assessing the efficacy of the shunt via fluoroscopic visualization of the shunt.
7. The method of claim 1 , wherein the shunt comprises an hourglass configuration when the first and second conical sections are in the expanded state.
8. The method of claim 1 , wherein the second conical section is configured to flank the atrial septum from within the right atrium in the expanded state.
9. The method of claim 1 , further comprising removing the sheath from the patient.