Shunt for redistributing atrial blood volume
A shunt for regulating blood pressure between a patient's left atrium and right atrium comprises an anchor comprising a neck region, first and second end regions, and a conduit affixed with the anchor that formed of a biocompatible material that is resistant to transmural and translation tissue ingrowth and that reduces a risk of paradoxical embolism.
1. A method for redistributing blood across a patient's interatrial septum between the patient's left atrium and the patient's right atrium, the method comprising:
percutaneously delivering an anchor having a first region, a second region, a neck region joining the first region to the second region, and an interior passageway extending therethrough to the interatrial septum in a contracted delivery state;
transitioning the anchor from the contracted delivery state to an expanded deployed state in which the first region extends into the patient's left atrium, the second region extends into the patient's right atrium, and the neck region lodges in a puncture formed in the interatrial septum;
after transitioning the anchor, percutaneously delivering a conduit having a first end, a second end, and a lumen extending therebetween within the interior passageway of the anchor in a contracted delivery state;
transitioning the conduit from the contracted delivery state to an expanded deployed state within the interior passageway of the anchor to fix the conduit within the interior passageway of the anchor such that the first end extends into the patient's left atrium and the second end extends into the patient's right atrium, the conduit having a length to limit pannus formation within the lumen of the conduit at the neck region in the expanded deployed state; and
shunting blood between the patient's left atrium and the patient's right atrium via the lumen of the conduit while limiting paradoxical emboli passing across the lumen during a transient pressure gradient reversal.
2. The method of claim 1 , wherein the anchor comprises an unencapsulated bare metal frame.
3. The method of claim 1 , wherein the anchor comprises a plurality of longitudinal struts interconnected by a plurality of circumferential sinusoidal struts.
4. The method of claim 1 , wherein the anchor has a diameter in the expanded deployed state larger than a diameter of the conduit, such that in the expanded deployed state, the anchor fills a larger opening in the interatrial septum than is needed to accommodate the conduit.
5. The method of claim 1 , wherein at least one of the anchor or the conduit comprises a skirt configured to prevent bypass flow between the anchor and the conduit.
6. The method of claim 1 , wherein the anchor comprises, in the expanded deployed state, a filter that excludes emboli from entering the lumen of the conduit.
7. The method of claim 1 , wherein at least one of the first region or the second region of the anchor is flared.
8. The method of claim 1 , wherein the lumen of the conduit comprises an encapsulated lumen wall, the encapsulated lumen wall resistant to transmural and translational tissue growth.
9. The method of claim 1 , wherein the lumen of the conduit has a diameter in the neck region in a range of 5 mm to 6.5 mm.
10. The method of claim 1 , wherein the lumen of the conduit is configured to provide high velocity flow therethrough.
11. The method of claim 1 , wherein the conduit comprises a tube of solid material.
12. The method of claim 1 , wherein the conduit comprises an hourglass shape in the expanded deployed state.
13. The method of claim 1 , wherein the first end of the conduit extends from the neck region of the anchor a distance of at least 3 mm into the patient's left atrium, thereby preventing pannus formation from narrowing the lumen of the conduit in the neck region.
14. The method of claim 1 , wherein the second end of the conduit extends from the neck region of the anchor a distance of at least 3 mm into the patient's right atrium, thereby preventing pannus formation from narrowing the lumen of the conduit in the neck region.
15. The method of claim 14 , wherein the second end of the conduit extends from the neck region of the anchor a distance of between 3 mm to 15 mm into the patient's right atrium.
16. The method of claim 1 , wherein the first end and/or second end of the conduit, in the expanded deployed state, are offset from, and do not contact, adjacent cardiac structures, thereby limiting pannus growth to an exterior surface of the anchor.
17. The method of claim 1 , wherein transitioning the conduit from the contracted delivery state to the expanded deployed state comprises expanding a balloon within the lumen of the conduit.
18. The method of claim 1 , wherein the conduit is fixed within the interior passageway of the anchor via mechanical interference.
19. The method of claim 1 , wherein the conduit, in the expanded deployed state within the interior passageway of the anchor, is located out of a natural circulation flow path of blood entering into the patient's right atrium from an inferior vena cava, thereby reducing a risk of emboli entrained in flow from the inferior vena cava being directed into the second end of the conduit.
20. The method of claim 1 , further comprising forming the puncture through a fossa ovalis of the interatrial septum, and percutaneously delivering the anchor through the puncture in the interatrial septum in the contracted delivery state.