Vascular Closure Device and Method of Closing a Vascular Access Hole Using Such a Device

Abstract

The present invention relates to a vascular closure device, comprising a self-expanding tubular vascular closure element, a retaining element surrounding the vascular closure element, the retaining element being arranged to hold the vascular closure element in the lumen of the retaining element in a configuration where the vascular closure element is not fully self-expanded, a tether that is threaded through the lumen of the retaining element, the tether being arranged so that, upon application of a first force to the tether which is greater than a threshold force, the tether disintegrates the retaining element so as to allow the vascular closure element to freely expand. It also relates to a system for delivering such a vascular closure device and to a method of closing a vascular access hole using a corresponding device.

Claims

1. Vascular closure device (10), comprising: a self-expanding tubular vascular closure element (12), a retaining element (14) surrounding the vascular closure element (12), the retaining element (14) being arranged to hold the vascular closure element in the lumen of the retaining element (14) in a configuration where the vascular closure element (12) is not fully expanded, a tether (16), the tether being arranged so that, upon application of a first force to the tether (16) which is greater than a threshold force, the tether (16) disintegrates the retaining element (14) to such an extent that the vascular closure element (12) can freely expand.

2. Vascular closure device (10) according to claim 1, the tether (16) being threaded through the lumen of the retaining element (14), the tether (16) being arranged so that, upon application of a first force to the tether which is greater than the threshold force, the tether cuts through the retaining element so as to allow the vascular closure element (12) to freely expand.

3. Vascular closure device (10) according to claim 1 or 2, the tether (16) being arranged so that the tether (16) extends from a first longitudinal end of the retaining element (14) to an opposite second longitudinal end of the retaining element (14), with both ends of the tether (16) being arranged outside of the assembly of the vascular closure element (12) and the retaining element (14).

4. Vascular closure device (10) according to claim 3, the ends of the tether (16) being joined together.

5. Vascular closure device (10) according to one of the preceding claims, further comprising a pullout-tether (18) coupled to the retaining element (14), the pullout-tether (18) being arranged for withdrawing the retaining element (14) from a patient's vasculature once the retaining element (14) has been cut.

6. Vascular closure device (10) according to one of the preceding claims, the retaining element (14) being made of PET.

7. Vascular closure device (10) according to claim 1, the retaining element (14) comprising a knitted sleeve arranged so as to surround the vascular closure element (12), the tether (16) being coupled to the knitted sleeve so that upon application of the first force larger than the threshold force, the knitted sleeve disintegrates so as to allow the vascular closure element (12) to expand.

8. Vascular closure device according to claim 7, the knitted sleeve comprising a thread made of UHMWPE.

9. Vascular closure device (10) according to one of the preceding claims, the vascular closure element (12) comprising a stent graft.

10. Vascular closure device (10) according to one of the preceding claims, the vascular closure element (12) comprising a bioresorbable material.

11. Vascular closure device (10) according to one of the claims 1-6, 9, and 10, when comprising the features of claim 2, the tether (16) being arranged so that between the first and the second longitudinal end of the retaining element (14), the tether (16) extends entirely on the inside of the retaining element (14).

12. Vascular closure device (10) according to one of the claims 1-6, 9, 10, and 11, when comprising the features of claim 2, the tether (16) being routed between a portion of the vascular closure element (12) that is suitable for sealing the vascular access hole (15) and the retaining element (14).

13. System for delivering a vascular closure device (10) according to one of the preceding claims, comprising: a catheter (20) for introduction into a patient's blood vessels, the vascular closure device (10) of one of the preceding claims, the assembly of the vascular closure element (12) and the retaining element (14) being arranged at a distal end of the catheter.

14. Method of closing a vascular access hole (15) inside a blood vessel (22), comprising: deploying the vascular closure device (10) according to one of claims 1 to 12 inside a patient's vasculature through the vascular access hole, with the tether (16) extending to the outside of the patient's body through the vascular access hole, applying a first pull force less than the threshold force on the tether (16) so as to pull the assembly of the vascular closure element and of the retaining element (14) against the vascular wall adjacent the vascular access hole, applying a second pull force that is greater than the threshold force on the tether (16) so as to disintegrate the retaining element (14) to thereby release the vascular closure element (10) to allow the vascular closure element to self-expand.

15. Method of claim 14, further comprising withdrawing the tether (16) from the patient's body.

16. Method of claim 14 or 15, further comprising removing the disintegrated retaining element (14) from the patient's body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 shows a system for delivering a vascular closure device according to an embodiment in a delivery configuration.

[0030] FIG. 2 shows the system according to FIG. 1 and a consideration where the catheter is in the process of being withdrawn.

[0031] FIGS. 3 and 4 show further steps in the deployment of the vascular closure element of the system according to FIGS. 1 and 2.

[0032] FIG. 5 shows the fully deployed vascular closure element.

DETAILED DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows, in subfigure a), a vascular closure device 10 during a first stage of deployment in a blood vessel 22. The blood vessel 22, which has a vascular access hole 15 that connects the blood vessel 22 to the outside of the patient's body and that may have been created during a surgery, for example an endovascular surgery, has arranged therein a catheter 20. The blood vessel 22 is, for example, the arteria femoralis. This catheter 20 comprises a sheath (introducer/guide sheath) 25 that extends through the vascular access hole 15 into the blood vessel 22. The distal end of the sheath 25 is arranged inside the blood vessel 22, and the proximal end is arranged outside of the blood vessel and comprises a gate 24 for the selective introduction and removal of components into and from the sheath 25. In that context, the word “proximal” refers to a direction along the sheath 25 towards the surgeon, and “distal” refers to the opposite direction away from the surgeon.

[0034] As can be seen in FIG. 1, the vascular closure device 10 has been positioned inside the blood vessel 22. This vascular closure device 10 comprises a vascular closure element (stent graft) 12 that is shown in more detail in FIG. 1b). Around that vascular closure element 12, a tube-like retaining element 14 made of a single layer PET sheath is wrapped so as to retain the vascular closure element 12 in the non-fully-expanded configuration. In that configuration, the assembly of the vascular closure element 12 and of the retaining element in a sheath form can be arranged inside the lumen of the sheath 25, which is the delivery configuration of the vascular closure device 10 (not shown).

[0035] Also shown is a pusher wire 11 that extends through the lumen of the vascular closure element 12 and through the lumen of the sheath 25. Provided proximally relative to the stent graft 12 is a pusher cone 28 that is dimensioned so that the pusher cone 28 can push the vascular closure element 12 out of the lumen of the sheath 25. Such a pusher wire 11 can be made of nitinol and can have, in embodiments, a thickness of from 0.02″ to 0.035″. The pusher wire 11 allows for pushing the vascular closure element 12 out of the lumen of the sheath 25 during deployment.

[0036] A tether 16 that can be made of a metal wire extends through the sheath 25 and is sandwiched between the vascular closure element 12 and the retaining element 14. Tether 16 could also be referred to as a loop split tether. The two ends of the tether 16, which could, in embodiments, also be referred to as a loop split wire, are lead through the lumen of the sheath 25 to a position beyond the proximal end of the sheath 25 where they are joined together. A pull ring 30 is arranged so that the tether 16 is slidably threaded through it. The pull ring 30 can be used for applying pull force onto the tether 16. It is to be noted that the pull ring 30 is entirely optional and does not need to be present. It is also to be noted that the pull ring 30 does not need to have a circular shape. Through pulling that tether 16, the vascular closure element 12 can be positioned adjacent the vascular access hole 15, as will be discussed in more detail below, and can be also released from the retaining element 14. The details of this positioning and release will be discussed subsequently with reference to FIGS. 2-5.

[0037] Furthermore, a pullout-tether 18 is provided that could also be referred to as a split sheath removal line. This pullout-tether 18 is connected to the retaining element 14 and is led through the interior of the sheath 25 so that the pullout-tether 18 extends beyond the proximal end of the sheath 25. As will be discussed more fully when discussing the subsequent drawings, this pullout-tether 18 can be used for removing the cut retaining element 14 from the patient's vasculature.

[0038] FIG. 1b) shows in more detail the structure of the vascular closure element (vascular plug) 12. As can be seen from that drawing, a base stent 13 is provided which has arranged thereon a patch 19 that can, in embodiments, be made of polylactic acid (PLLA). However, as discussed previously, other materials can also be used. The base stent 13 itself is made of a self-expanding material. In embodiments, nitinol was used for the base stent 13, which was cut with a femto laser technology for selective material ablation. In embodiments, the base stent 13 had an expanded diameter of about 9-12 mm and was covered on one circumferential half with a PLLA patch 19 that had a length of about 10 mm. Such a length has been found to cover, with a great safety margin, the puncture access sites in femoral arteries.

[0039] In the presently shown embodiment in FIG. 1a), the tether 18 is looped between the PLLA patch 19 and the retaining element 14. This allows for a more accurate positioning of that patch adjacent the vascular access hole 15, since pulling on the tether 18 will automatically position the patch 19 adjacent the vascular access hole 15.

[0040] In embodiments, a 5 F outer diameter catheter was used as the sheath 25. An example system was a Halo 1 catheter sheath provided Becton Dickinson and Company, which has a 4 F inner diameter.

[0041] Whilst FIG. 1a) shows a configuration where the assembly of the vascular closure element 12 and retaining element 14 has just been pushed out of the distal end of the catheter 20, FIG. 2 shows a configuration that happens somewhat later during the deployment of the vascular closure element 12. As can be seen from FIG. 2, the sheath 25 has been largely withdrawn from the blood vessel 22 whilst still facilitating haemostasis. Whilst the sheath 25 still extends through the vascular access hole 15, it extends much less into the blood vessel 22 then in the configuration shown in FIG. 1a). In the configuration shown in FIG. 2, the vascular closure element 12 is still restrained by the retaining element 14 so that its cross-sectional diameter is significantly less than the diameter of the blood vessel 22. Accordingly, the vascular closure element 12 can move freely inside that blood vessel 22 and can thus, by means of applying a pull force to the tether 16, be moved in its position inside the blood vessel 22.

[0042] FIG. 3 shows the next step in the deployment of the vascular closure element 12. As can be seen from that figure, the tether 16 extends out of the distal end of the sheath 25 and is sandwiched between the vascular closure element 12 (more precisely, the PLLA patch 19) and the retaining element 14. However, we can be seen from that figure, the pusher wire 11 has been withdrawn from the blood vessel 22.

[0043] When now applying a pulling force to the pull ring 30, the tether 16 is pulled through the sheath 25 which transitions the system from the configuration shown in FIG. 3 to that shown in FIG. 4. Due to the force that is applied to the tether 16 being symmetric, the vascular closure element 12 gets positioned so that the vascular closure element 12 is centred on the vascular access hole 15. Accordingly, since the tether 16 is arranged so that the tether 16 is sandwiched between the retaining element 14 and the patch 19, the patch 19 is arranged adjacent to the vascular access hole 15 and is thus adequately positioned for closing that vascular access hole 15 from the inside. However, as can also be seen from FIG. 4, in that configuration, the vascular closure element has still too small a diameter to be fixed in position relative to the blood vessel 22 thanks to the presence of the retaining element 14. That is, if the tether 16 (as well as the pullout-tether 18) were not present, the assembly of the vascular closure element 12 and the retaining element 14 would move freely inside the blood vessel 22, which is undesirable if one wants to close the vascular access hole 15.

[0044] When the configuration that is shown in FIG. 4 has been reached, the surgeon would then apply a stronger pull force on the tether 16. This pull force would lead to the tether 16 cutting through the retaining element 14 at those places where the tether 16 is in contact with the retaining element 14.

[0045] Since the tether 16 extends along the entire length of the retaining element 14, the tether 16 will cut the entire length of the retaining element 14. In consequence, the thus cut retaining element 14 would no longer exert a restraining force on the self-expansion of the vascular closure element 12. This vascular closure element 12 will then self-expand due to the vascular closure element 12 being exposed to the patient's blood stream and thus push against the walls of the blood vessel 22. The vascular closure element 12 will thereby push the patch 19 against the vascular access hole 15 to thereby seal the vascular access hole 15. Subsequently, the surgeon would then withdraw the tether 16 and also, using the pullout-tether 18, the cut remainder of the retaining element 14 from the patient's body via the sheath 25 of the catheter 20.

[0046] In that way, the configuration shown in FIG. 5 is achieved where the vascular closure element 12 has sufficiently self-expanded so as to push the patch 19 against the vascular access hole 15 that is shown, in the configuration shown in FIG. 5, as having partially healed. The thus closed vascular access hole 15 is thus sealed from the inside so that blood cannot leak out of it. Since the patch 19 has been made of a bioresorbable material, the patch 19 will dissolve with time so that the cross-section of the vascular closure element 12 will be reduced and will finally only be the cross-section of the base stent 13, which therefore reduces the impact on blood flowing through the blood vessel 22.

[0047] It is to be noted that the naturally occurring blood pressure will also serve to push the patch 19 against the vascular access hole 15 which therefore improves the sealing and will reduce bleeding. Further, since after the placement of the vascular closure element 12, and the withdrawal of the tether and the pullout-tether 18, there are no components that extend to the outside of the blood vessel 22, the risk of an infection is reduced. It is additionally believed that having such a way of closing the wound will reduce the risk of subcutaneous bleeding as well as the creation of haematomas and pseudo-aneurysms. Additionally, due to the absence of small parts and a sealing agent, which might be dislodged, there is a smaller risk of an ipsilateral leg ischaemia.