Delivery of a prosthetic valve
Apparatus includes a delivery tool and a prosthetic valve, the prosthetic valve includes a first frame, and a second frame coupled to the first frame. The delivery tool includes a first catheter, a second catheter, and a rod. A steerable portion of the second catheter extends out of the first catheter, and a steerable distal portion of the rod extends out of the second catheter. An extracorporeal rod-controller is operably coupled to the rod such that operating the extracorporeal rod-controller steers the steerable distal portion of the rod. In a delivery state of the apparatus, the prosthetic valve is compressed onto the rod, distal to the distal end of the second catheter, and the apparatus is transfemorally and transseptally advanceable into a left atrium of a heart of a subject. Other embodiments are also described.
1. Apparatus, comprising:
a delivery tool, comprising:
a first catheter;
a second catheter;
having a steerable distal portion, and
extending through the first catheter such that the steerable distal portion of the second catheter is disposed out of a distal end of the first catheter;
an extracorporeal second-catheter controller:
coupled to a proximal portion of the second catheter, and
operably coupled, via the second catheter, to the steerable distal portion of the second catheter such that operating the extracorporeal second-catheter controller steers the steerable distal portion of the second catheter;
a rod:
having a steerable distal portion, and
extending through the second catheter and out of a distal end of the second catheter such that the steerable distal portion of the rod is disposed out of the distal end of the second catheter; and
an extracorporeal rod-controller:
coupled to a proximal portion of the rod, and
operably coupled, via the rod, to the steerable distal portion of the rod such that operating the extracorporeal rod-controller steers the steerable distal portion of the rod independently of the steering of the steerable distal portion of the second catheter by the extracorporeal second-catheter controller; and
a prosthetic valve:
comprising a first frame, and a second frame coupled to the first frame, wherein the apparatus has a delivery state in which (i) the prosthetic valve is compressed onto the steerable distal portion of the rod, distal to the distal end of the second catheter, and (ii) the prosthetic valve is transfemorally and transseptally advanceable into a left atrium of a heart of a subject by transfemorally and transseptally advancing the delivery tool.
2. The apparatus according to claim 1 , wherein:
the first catheter defines a lumen that has an internal diameter, and
the second catheter has an external diameter that is smaller than the internal diameter of the first catheter, and
in the delivery state, the prosthetic valve has a compressed width that is greater than the internal diameter of the first catheter.
3. The apparatus according to claim 2 , wherein:
the delivery tool further comprises a sheath, and
in the delivery state:
the prosthetic valve is disposed within the sheath, and
the prosthetic valve is transfemorally and transseptally advanceable into the left atrium by transfemorally and transseptally advancing the delivery tool while the prosthetic valve is (i) compressed onto the steerable distal portion of the rod, distal to the distal end of the second catheter, and (ii) disposed within the sheath.
4. The apparatus according to claim 3 , wherein the sheath is sufficiently flexible to passively bend in response to steering of the rod.
5. The apparatus according to claim 3 , wherein the sheath comprises a low-friction material.
6. The apparatus according to claim 5 , wherein the low-friction material is polytetrafluoroethylene.
7. The apparatus according to claim 3 , wherein the sheath is intracorporeally slidable off of the prosthetic valve so as to expose the prosthetic valve within the heart of the subject.
8. The apparatus according to claim 7 , wherein:
the second frame comprises a valve body,
the prosthetic valve comprises a plurality of snares,
in the delivery state, each of the plurality of snares is disposed against the valve body,
in an expanded state of the prosthetic valve, the snares protrude radially outward from the valve body,
the delivery tool is configured to deploy the prosthetic valve by transitioning from the delivery state, by intracorporeally transitioning the prosthetic valve toward the expanded state via an intermediate state of the prosthetic valve in which:
each of the plurality of snares:
is exposed from the sheath by the sheath having been slid off of the snares, and
protrudes radially outward from the valve body at an acute angle with respect to the valve body, and
at least part of the valve body remains compressed onto the rod and disposed within the sheath.
9. The apparatus according to claim 8 , wherein the prosthetic valve comprises a shape memory material configured to automatically transition from the delivery state toward the expanded state via the intermediate state.
10. The apparatus according to claim 7 , wherein the delivery tool comprises a plurality of restraints, and wherein, in the delivery state:
the plurality of restraints restrain the prosthetic valve,
the sheath is configured to be drawn proximally, relative to the prosthetic valve, thereby unsheathing the prosthetic valve and the restraints, and
each of the plurality of restraints is configured to be controllably disengaged from the prosthetic valve.
11. The apparatus according to claim 10 , wherein the second frame defines a valve body and the prosthetic valve comprises a plurality of snares, and in the delivery state:
a first restraint of the plurality of restraints restrains the snares,
a second restraint of the plurality of restraints restrains the valve body, and
a third restraint of the plurality of restraints restrains the first frame.
12. The apparatus according to claim 11 , wherein the apparatus is configured such that, while the second restraint restrains the second frame, and the third restraint restrains the first frame, disengaging the first restraint allows the snares to extend radially away from the second frame.
13. The apparatus according to claim 12 , wherein the apparatus is configured such that unsheathing the prosthetic valve and the restraints facilitates controllable disengagement of the restraints from the prosthetic valve.