Implant delivery and retrieval systems and methods

1. A catheter system, comprising:

a catheter having a lumen along a longitudinal axis;

a docking cap coupled to the catheter and including a body having a side surface defining a chamber, and a proximal opening coaxial with the longitudinal axis and extending into the chamber, wherein the docking cap includes a first cap key and a second cap key disposed radially around the side surface;

a retriever including a first sheath having a first snare lumen and a second sheath having a second snare lumen, wherein the first sheath and the second sheath extend distally through the proximal opening and the chamber; and

a plurality of snare loops extending distally within the first sheath and the second sheath through the proximal opening and the chamber in an engaged position and a disengaged position, wherein a first snare wire and a second snare wire extend longitudinally through the first snare lumen at a first radial position between the first cap key and the second cap key, wherein the first snare wire and the second snare wire extend longitudinally through the second snare lumen at a second radial position radially between the first cap key and the second cap key and opposite to the first radial position, wherein the first snare wire extends from the first snare lumen into the second snare lumen to form a first snare loop of the plurality of snare loops pointing in a first direction, wherein the second snare wire extends from the first snare lumen into the second snare lumen to form a second snare loop of the plurality of snare loops pointing in a second direction different from the first direction, and wherein the first snare loop and the second snare loop form a docking space and the plurality of snare loops are movable between the engaged position and the disengaged position by translating the first snare wire and the second snare wire within the first snare lumen and the second snare lumen to change a size of the docking space.

2. The catheter system of claim 1 , wherein the first sheath and the second sheath are each translatable within the chamber and the proximal opening.

3. The catheter system of claim 1 , wherein a first portion of the first sheath having the first snare lumen containing both the first snare wire and the second snare wire is disposed at the first radial position radially opposite to a second portion of the second sheath having the second snare lumen containing both the first snare wire and the second snare wire at the second radial position.

4. The catheter system of claim 1 , wherein a junction between the plurality of snare loops and a docking projection of a leadless pacemaker in the engaged position permits movement of the leadless pacemaker relative to the longitudinal axis.

5. The catheter system of claim 4 , wherein the movement of the leadless pacemaker relative to the longitudinal axis includes at least one of movement parallel to the longitudinal axis or at an angle relative to the longitudinal axis.

6. The catheter system of claim 1 , wherein the docking cap includes a first tracker and a second tracker disposed in the chamber, wherein the first sheath extends through and is translatable within the first tracker at the first radial position, and wherein the second sheath extends through and is translatable within the second tracker at the second radial position.

7. The catheter system of claim 1 , wherein the first cap key and the second cap key are configured to provide torque transmission by matingly engaging one or more docking surfaces of a docking projection of a leadless pacemaker.

8. The catheter system of claim 7 , wherein the docking projection includes a docking button.

9. A catheter system comprising:

a docking cap including a body having a side surface defining a chamber, and a proximal opening extending into the chamber, wherein the docking cap includes a first cap key and a second cap key disposed radially around the side surface;

a retriever including a first sheath having a first snare lumen and a second sheath having a second snare lumen, wherein the first sheath and the second sheath extend distally through the proximal opening and the chamber; and

a plurality of snare loops extending distally within the first sheath and the second sheath through the proximal opening and the chamber in an engaged position and a disengaged position, wherein a first snare wire and a second snare wire extend longitudinally through the first snare lumen at a first radial position between the first cap key and the second cap key, wherein the first snare wire and the second snare wire extend longitudinally through the second snare lumen at a second radial position radially between the first cap key and the second cap key and opposite to the first radial position, wherein the first snare wire extends from the first snare lumen into the second snare lumen to form a first snare loop of the plurality of snare loops having a first peak at the central axis, wherein the second snare wire extends from the first snare lumen into the second snare lumen to form a second snare loop of the plurality of snare loops having a second peak at the central axis, and wherein the plurality of snare loops are movable between the engaged position and the disengaged position by translating the first snare wire and the second snare wire within the first snare lumen and the second snare lumen, the translation of the first snare wire and the second snare wire moving the first peak radially inwards toward the second peak to the engaged position and radially outwards away from the second peak to the disengaged position.

10. The catheter system of claim 9 , wherein each of the first sheath and the second sheath includes an end coil.

11. The catheter system of claim 10 , wherein each of the end coils is radiopaque.

12. The catheter system of claim 9 , wherein the docking cap includes a first tracker and a second tracker disposed in the chamber, wherein the first sheath extends through and is translatable within the first tracker at the first radial position, and wherein the second sheath extends through and is translatable within the second tracker at the second radial position.

13. The catheter system of claim 9 , wherein the first snare loop and the second snare loop form a docking space, the docking space having a smaller size in the engaged position than in the disengaged position.

14. The catheter system of claim 9 , wherein the first snare wire and the second snare wire are tightened around a docking projection of a leadless pacemaker disposed within the docking space in the engaged position.

15. The catheter system of claim 14 , wherein the docking projection is receivable within the chamber.

16. The catheter system of claim 9 , wherein each of the first snare wire and the second snare wire are attached to at least one mandrel.

17. A method for engaging a leadless catheter, the method comprising:

disposing a docking space relative to a docking projection extending from a surface of a body of a leadless pacemaker, the docking space formed by a plurality of snare loops extending distally within a first sheath and a second sheath through a proximal opening and a chamber of a docking cap in an engaged position and a disengaged position, wherein a first snare loop of the plurality of snare loops points in a first direction and a second snare loop of the plurality of snare loops points in a second direction different than the first direction, wherein the first snare loop is formed from a first snare wire extending from a first snare lumen of the first sheath into a second snare lumen of the second sheath, wherein the second snare loop is formed from a second snare wire extending from the first snare lumen of the first sheath into the second snare lumen of the second sheath, wherein the first snare wire and the second snare wire extend longitudinally through the first snare lumen at a first radial position between a first cap key and a second cap key of the docking cap, wherein the first snare wire and the second snare wire extend longitudinally through the second snare lumen at a second radial position radially between the first cap key and the second cap key and opposite to the first radial position, and wherein the first cap key and the second cap key are disposed radially around a side surface of a body of the docking cap defining the chamber;

advancing the first snare loop and the second snare loop over the leadless pacemaker until the docking projection is disposed in the docking space in the disengaged position;

decreasing a size of the docking space by retracting the first snare wire and the second snare wire into the first snare lumen and the second snare lumen until the first snare wire and the second snare wire tighten around the docking projection in the engaged position; and

retracting the first sheath and the second sheath into a lumen of a catheter until the docking projection is positioned within the chamber radially between the first cap key and the second cap key of the docking cap.

18. The method of claim 17 , wherein the docking cap includes a first tracker and a second tracker disposed in the chamber, the first sheath retractable along the first tracker at the first radial position between the first cap key and the second cap key and the second sheath retractable along the second tracker at the second radial position between the first cap key and the second cap key.

19. The method of claim 17 , further comprising:

retrieving the leadless pacemaker by translating the catheter.

20. The method of claim 17 , further comprising:

delivering the leadless pacemaker by translating the catheter.