Techniques for guided advancement of a tool
A sheath is transluminally introduced a sheath into an atrium of a heart of a subject. A guide member is advanced out of the sheath and to a chorda tendinea of the heart, the guide member having a proximal portion that includes a longitudinal element, and a distal portion that includes a helical chord-engaging element. The chord-engaging element is wrapped around the chorda tendinea. While the chord-engaging element remains wrapped around the chorda tendinea, (i) the chord-engaging element is slid over the chorda tendinea toward a papillary muscle that is coupled to the chorda tendinea; and (ii) subsequently, a tool is moved out of the sheath and toward the papillary muscle by sliding the tool along the longitudinal element. Other embodiments are also described.
1. A method for use with a papillary muscle of a heart of a subject, the papillary muscle being coupled to a chorda tendinea of the heart of the subject, the method comprising:
transluminally introducing a sheath into an atrium of the heart;
advancing a guide member out of the sheath and to the chorda tendinea, the guide member having a proximal portion that includes a longitudinal element, and a distal portion that includes a helical chord-engaging element;
wrapping the chord-engaging element around the chorda tendinea; and
while the chord-engaging element remains wrapped around the chorda tendinea:
sliding the chord-engaging element over the chorda tendinea toward the papillary muscle; and
subsequently, moving a tool out of the sheath and toward the papillary muscle by sliding the tool along the longitudinal element.
2. The method according to claim 1 , further comprising, following the step of advancing, anchoring a tissue anchor to ventricular muscle tissue using the tool.
3. The method according to claim 2 , wherein anchoring the tissue anchor comprises anchoring the tissue anchor to ventricular muscle tissue in a vicinity of the papillary muscle.
4. The method according to claim 3 , wherein anchoring the tissue anchor comprises anchoring the tissue anchor to ventricular muscle tissue within 1 cm of the papillary muscle.
5. The method according to claim 3 , wherein anchoring the tissue anchor comprises anchoring the tissue anchor to the papillary muscle.
6. The method according to claim 2 , wherein anchoring the tissue anchor comprises anchoring a tissue anchor that is reversibly coupled to a guidewire.
7. The method according to claim 2 , wherein the tool includes a lance, and the method further comprises, prior to anchoring the tissue anchor, stabilizing the tool with respect to the ventricular muscle tissue by penetrating the ventricular muscle tissue with the lance.
8. The method according to claim 7 , further comprising retracting the lance into the tool.
9. The method according to claim 1 , wherein the step of advancing further comprises advancing, to the heart of the subject, a housing that is slidable along the guide member.
10. The method according to claim 9 , further comprising, prior to the step of advancing, advancing a guidewire to a ventricle of the heart, wherein advancing the housing comprises sliding the housing over the guidewire.
11. The method according to claim 10 , wherein advancing the guidewire comprises advancing a distal portion of the guidewire between at least two chordae tendineae of the subject.
12. The method according to claim 9 , further comprising, subsequent to the step of advancing, sliding the chord-engaging element distally out of the housing.
13. The method according to claim 12 , further comprising, subsequent to the step of wrapping and prior to the step of moving, proximally withdrawing the housing and decoupling the housing from the guide member while maintaining the chord-engaging element wrapped around the chorda tendinea.
14. The method according to claim 12 , wherein sliding the chord-engaging element distally out of the housing comprises transitioning the chord-engaging element from a generally straight state into a helical state.