Intracardiac capsule and explantation accessory
An autonomous capsule includes a tubular body provided at its distal end with an anchoring screw, and in its proximal region of a capture groove. An explantation accessory includes a reinforced catheter combined with a flexible wire which can slide in the catheter and has a deformable loop which can be clamped by gradual introduction of its ends in the catheter under the effect of a traction exerted on the wire. During tightening, the capture groove receives the wire loop, allowing, after complete tightening, to secure in tension and rotation an assembly formed by the catheter, the capsule, and the wire. The reinforced catheter is then used to transmit a tensile force and an axial torque from its proximal end to its distal end, allowing safe unscrewing of the capsule and its extraction through the patient venous network.
1. An intracardiac capsule assembly, the assembly comprising:
an autonomous capsule comprising a tubular body having at a distal end a screw anchoring member adapted to penetrate tissue of a wall of an organ of a patient; and
an explantation accessory, including:
a catheter; and
a flexible wire, slidably movable in the catheter and having at an emerging distal end a deformable loop, the loop configured to be clamped by gradual introduction of the loop in the catheter under an effect of a traction exerted on the flexible wire;
wherein the catheter is a reinforced catheter capable of transmitting a traction force and an axial torque from a proximal end to a distal end;
wherein, in a proximal region, the capsule comprises a capture member adapted to receive the loop of the wire during a clamping thereof and to secure in traction and rotation the intracardiac capsule assembly formed by the catheter, the capsule, and the wire after clamping of the loop;
wherein the capture member comprises at least one capture groove formed within the proximal end region of the capsule, each groove having a diameter less than a diameter of the tubular body and a contour extending along a curvilinear outline oriented in an oblique plane relative to a central axis of the tubular body, and the contour being an open contour comprising two ends which proximally open adjacent to an axial end point of the tubular body; and
wherein a portion of the proximal end region of the capsule in which the at least one capture groove is formed has a diameter substantially the same as the diameter of the tubular body.
2. The assembly of claim 1 , wherein the oblique plane according to which the curvilinear contour of each capture groove is oriented forms an angle of between 30° and 60° relative to the central axis of the tubular body.
3. The assembly of claim 1 , wherein each capture groove is symmetrical with respect to a longitudinal axial plane of the tubular body.
4. The assembly of claim 1 , wherein a profile of a cross section of each capture groove has on a proximal side an undercut angle.
5. The assembly of claim 1 , comprising two symmetrical capture grooves diametrically opposed with respect to the central axis of the tubular body.
6. The assembly of claim 1 , wherein depth and width dimensions of the at least one groove are between 1 and 3 times a diameter of the flexible wire loop.
7. The assembly of claim 1 , wherein the reinforced catheter carries at its distal end a specific tip comprising:
a rigid distal tip portion, extending the catheter beyond the distal end thereof; and
a proximal tip portion mounted on the catheter and elastically deformable so as to provide degrees of freedom in axial flexion for the rigid distal tip portion.
8. The assembly of claim 7 , wherein the rigid distal tip portion comprises symmetrical notches for receiving the ends of the loop of the wire.
9. The assembly of claim 7 , wherein the specific tip is a helical spring comprising successively:
a first series of turns surrounding the distal end of the catheter and forming the rigid distal tip portion;
a second series of turns extending beyond the distal end of the catheter and forming the proximal tip portion; and
a third series of turns at a free end of the spring with contiguous turns and symmetrical notches for receiving the ends of the loop of the wire.
10. The assembly of claim 1 , wherein the assembly further comprises:
a guidable catheter configured to receive the reinforced catheter with the wire introduced therein, this guidable catheter comprising at its distal end a tubular protective tip defining an inner volume dimensioned to accommodate the capsule after explantation.