Device and method for controlling in-vivo pressure
A differential pressure regulating device is provided for controlling in-vivo pressure in a body, and in particularly in a heart. The device may include a shunt being positioned between two or more lumens in a body, to enable fluids to flow between the lumens, and an adjustable flow regulation mechanism being configured to selectively cover an opening of the shunt, to regulate the flow of fluid through the shunt in relation to a pressure difference between the body lumens. In some embodiments a control mechanism coupled to the adjustable flow regulation mechanism may be provided, to remotely activate the adjustable flow regulation mechanism.
1. A device for implantation within an atrial septum of a patient's heart to treat a heart condition, the device comprising:
a shunt comprising flexible material and configured to transition between a collapsed delivery state and an expanded deployed state, the shunt further configured to engage an opening in the atrial septum in the expanded deployed state and defining a continuous opening in the atrial septum to permit passage of blood through the atrial septum via the shunt, the continuous opening having an adjustable cross-sectional area such that blood flow across the atrial septum through the continuous opening of the shunt is adjustable.
2. The device of claim 1 , wherein the shunt is configured to permit passage of blood through the atrial septum to unload an excessive filling pressure of a left ventricle in a patient with congestive heart failure.
3. The device of claim 1 , wherein the shunt comprises a flexible metal.
4. The device of claim 3 , wherein the flexible metal comprises Nitinol.
5. The device of claim 1 , wherein the shunt comprises a shape-memory material.
6. The device of claim 1 , wherein the shunt is configured to self-expand from the collapsed delivery state to the expanded deployed state.
7. The device of claim 1 , wherein the shunt is configured to protrude into at least one of a right atrium and a left atrium of the patient in the expanded deployed state.
8. The device of claim 1 , further comprising a flexible membrane disposed within the shunt to define the continuous opening in the atrial septum.
9. The device of claim 8 , further comprising a spring configured to expand and contract the flexible membrane responsive to changes in blood pressure differential across the atrial septum, thereby changing the cross-sectional area of the continuous opening.
10. The device of claim 9 , wherein the spring comprises a predetermined spring tension to respond in a controlled manner to changes in blood pressure differential across the atrial septum.
11. The device of claim 1 , wherein the rate of blood flow through the shunt, cross-sectional area of the continuous opening, and blood pressure differential across the atrial septum have a relationship dependent on a predetermined pressure differential threshold.
12. The device of claim 1 , further comprising a coating to increase bio-compatibility.
13. The device of claim 1 , further comprising an anchor for retaining the shunt in the opening in the atrial septum in the expanded deployed state.
14. A method for treating a heart condition, the method comprising:
delivering a shunt within a puncture of an atrial septum of a patient's heart in a collapsed delivery state;
transitioning the shunt from the collapsed delivery state to an expanded deployed state within the atrial septum, the shunt defining a continuous opening within the atrial septum in the expanded deployed state; and
permitting blood flow across the atrial septum via the continuous opening of the shunt,
wherein a cross-sectional area of the continuous opening is adjustable such that blood flow across the atrial septum through the continuous opening of the shunt is adjustable.
15. The method of claim 14 , wherein delivering the shunt within the puncture of the atrial septum comprises delivering the shunt in a minimally invasive procedure.
16. The method of claim 14 , wherein delivering the shunt within the puncture of the atrial septum comprises:
advancing a guidewire and dilator within a puncture of an atrial septum of a patient's heart;
advancing a sheath over the guidewire and dilator; and
removing the dilator from the patient's body.
17. The method of claim 14 , wherein transitioning the shunt from the collapsed delivery state to the expanded deployed state within the atrial septum comprises:
advancing a delivery catheter mounted to the shunt in the collapsed delivery state through a sheath positioned within the puncture of the atrial septum until a first end of the shunt self-expands within a first atrium of the patient's heart; and
retracting the sheath relative to the atrial septum until a second end of the shunt self-expands within a second atrium of the patient's heart.
18. The method of claim 17 , further comprising retracting the delivery catheter and retracting the sheath relative to the atrial septum until the first end is seated against the atrial septum prior to retracting the sheath until the second end of the shunt self-expands within the second atrium.
19. The method of claim 14 , further comprising creating the puncture within the atrial septum of a patient's heart.
20. The method of claim 17 , further comprising removing the sheath and the delivery catheter from the patient's body.
21. The method of claim 17 , further comprising, after the shunt self-expands within the first atrium, retracting the delivery catheter relative to the shunt.
22. The method of claim 17 , further comprising, after the first end of the shunt self-expands within the first atrium but prior to retracting the sheath until the second end of the shunt self-expands within the second atrium, retracting the delivery catheter and retracting the sheath relative to the atrial septum.
23. The method of claim 17 , further comprising controlling delivery of the shunt using a control wire.
24. The method of claim 16 , further comprising, after transitioning the shunt from the collapsed delivery state to the expanded deployed state within the atrial septum, removing the guidewire from the patient's body.
25. The method of claim 14 , wherein permitting the blood flow across the atrial septum via the continuous opening of the shunt is configured to treat heart failure.
26. The method of claim 14 , wherein permitting the blood flow across the atrial septum via the continuous opening of the shunt is configured to treat pulmonary hypertension.
27. The method of claim 14 , wherein the shunt comprises a flexible metal.
28. The method of claim 27 , wherein the flexible metal comprises Nitinol.
29. The method of claim 14 , wherein the shunt comprises a shape-memory material.
30. The method of claim 29 , wherein the shunt further comprises a super elastic alloy.
31. The device of claim 5 , wherein the shunt further comprises a super elastic alloy.
32. The device of claim 1 , wherein the shunt is configured to permit passage of blood through the atrial septum to treat pulmonary hypertension.
33. The device of claim 1 , wherein the cross-sectional area of the continuous opening is from 3.5 mm 2 to 24 mm 2 for blood flow through the shunt.
34. The device of claim 1 , wherein the shunt is configured to provide enhanced blood flow across the atrial septum via the continuous opening when the interatrial pressure gradient ranges from greater than a threshold between 0 and 25 mmHg.
35. The device of claim 1 , wherein the cross-sectional area of the continuous opening is dependent on blood pressure differential across the atrial septum such that blood flow through the shunt changes responsive to change in the blood pressure differential across the atrial septum.
36. The device of claim 1 , wherein the shunt further comprises a flow regulating mechanism for adjusting the cross-sectional area of the continuous opening of the shunt.