DELIVERY CATHETER SYSTEM

A delivery catheter system includes a catheter and an integrated embolic filter that is deployable prior to the delivery of a prosthesis in a patient's vasculature and retrievable after delivery of said prosthesis. The embolic filter is moveable from a collapsed state, in which the embolic filter is retained within the catheter body, to a deployed state in which the embolic filter extends from the catheter body and, in use, into contact with an inner wall of a patient's vasculature.

FIELD OF THE INVENTION

The present invention relates to a delivery catheter system.

BACKGROUND

Catheters have long been used for the treatment of diseases of the cardiovascular system, such as treatment or removal of stenosis. More recently, catheters have been used for replacement of heart valves, in particular, the aortic valve in a procedure sometimes known as transcatheter aortic valve implantation (TAVI). TAVI is now the principal therapeutic option in patients with severe aortic stenosis deemed inoperable or at high surgical risk. Over 300,000 TAVI procedures were performed worldwide in 2018, and the mortality benefits of TAVI in inoperable and high-risk surgical patients have been recognised. However, the benefit of TAVI is attenuated by the occurrence of major disabling stroke which is associated with increased mortality and in the short term reduced quality of life. During TAVI, extensive manipulation of the calcified native valve and aortic wall takes place using large-sized catheters and rigid delivery systems. Subsequently, balloon valvuloplasty, positioning and implanting of the valve, and possibly post-dilation, takes place. Consequently, dislodgement and embolization of aortic debris and crushed calcified native valves seems inevitable and can provoke stroke by reaching brain vessels.

Cerebral embolic protection devices have been developed to reduce the risk of stroke by providing an efficient protection of the entire brain. To perform well, the device requires to have a minimum filtering porosity, a good anchoring on the vessel without damaging the vessel and a good stability by withstanding the blood pressure.

Current embolic protection devices on the market/in development include the Boston Scientific Sentinel (RTM) device, the Keystone Heart TriGUARD 3™ device, the Edwards Life Sciences Embrella device, the Emboline Emboliner™ device, and the Innovative Cardiovascular Solutions Emblok™ system. However, all these devices and systems are delivered separately from the delivery TAVI device.

SUMMARY

According to the present invention there is provided a delivery catheter system comprising: a catheter including an elongate catheter body having a distal tip and a capsule containing a deliverable prosthesis; and an integrated embolic filter, the embolic filter deployable prior to the delivery of a prosthesis in a patient's vasculature and retrievable after delivery of said prosthesis, wherein the embolic filter is moveable from a collapsed state, in which the embolic filter is retained within the catheter body, to a deployed state in which the embolic filter extends from the catheter body and, in use, into contact with an inner wall of a patient's vasculature.

Traditionally, embolic filter devices are placed separately from the delivery device which implies an additional step before the procedure. Surgeons need to be implanted first the embolic protection device via the right radial artery. Unexperienced cardiac surgeons do not use cerebral protection device due to the additional time required to implement them. The present arrangement provides an integrated embolic filters, which removes the need for two separate processes.

It will be appreciated that the delivery catheter assembly may be used for a range of different purposes, and the article being delivered will vary accordingly. The delivery catheter assembly may be used to place a stent in a patient's vasculature, and as such the article may be a stent. The delivery catheter assembly may be used for a transcatheter aortic valve implantation, and as such the article may be a replacement valve. Alternatively, the delivery catheter assembly may be used for any type of valve replacement procedure.

The article delivery catheter may be a transcatheter aortic valve implantation (TAVI) delivery catheter, a stent delivery catheter, a tool delivery catheter any other type of valve delivery catheter.

The embolic filter may be retained in the collapsed state by the catheter body, and wherein relative movement between the catheter body and the embolic filter in a first direction enables the embolic filter to move from the collapsed state to the deployed state.

The delivery catheter assembly may comprise a deflecting member attached to an internal surface of the catheter and to a control member. The control member may be configured to manipulate the deflecting member so as to adjust the position of the catheter within the vasculature of a patient, in use.

By providing an arrangement capable of deflecting the external catheter, the internal catheter can be centralized in the vessel of a patient, which centralizes the prosthesis delivery catheter. This can advantageously reduce contact with the vessel wall and/or help with deployment of an article.

The embolic filter may be connected to the internal catheter at or near a distal tip thereof.

The catheter may comprise an elongate catheter body having a distal tip and a capsule containing a deliverable prosthesis, and the embolic filter may be connected to the catheter proximal to the capsule.

The embolic filter may be connected to the internal catheter by adhesive, sewing, crimping or thermobonding.

The embolic filter may be connected to a releasable fastener that is configured to releasably engage the catheter so as to releasably attach the embolic filter to the catheter.

The delivery catheter assembly may be configured such that relative movement between the catheter and the capsule in the first direction beyond a predetermined distance causes the releasable fastener to disengage from the capsule.

The delivery catheter assembly may be configured such that relative movement between the catheter and the capsule in a second, retraction, direction beyond a predetermined distance causes the releasable fastener to engage from capsule.

The embolic filter may be connected to a resilient fastener, e.g. a c-clip or coil.

The resilient fastener may be urged into engagement with an external surface of the capsule in a first, e.g. retracted, position so as to releasably attach the embolic filter to the internal catheter.

The resilient fastener may expand into an internal groove on the catheter in a second, e.g. advanced, position such that the resilient fastener disengages from the capsule to enable the capsule to be advanced independently of the embolic filter.

The catheter may comprise an abutment surface configured and arranged to abut against the resilient fastener when the catheter from a position beyond the second, advanced, position past said second, advanced position so as to move the resilient fastener along a tapered surface of the internal groove so as to be urged into engagement with an external surface of the capsule and releasably attach the embolic filter to the capsule.

Relative movement between the catheter and the capsule in a second direction, opposite to the first direction, may move the embolic filter from the deployed state to the collapsed state.

The embolic filter may comprise a support frame, e.g. a nitinol support frame, and a porous polymeric membrane covering the support frame.

The support structure may comprise a shape memory material such that the support frame acts as a deployment arrangement to move the embolic filter from the collapsed state into the deployed state.

The porous polymeric membrane may be a biocompatible fabric comprising a pore size of between 100 and 200 nanometers.

According to a second aspect of the invention there is provided an introducer device comprising: an introducer sheath, wherein the catheter is arranged, e.g. substantially coaxially, within the introducer sheath, in use.

The advantage of this arrangement is that it helps to avoid the need for having two catheters in parallel in the vessel which could lead to interaction and bring complications during the procedure.

The introducer device may comprise a control member, e.g. a handle or rotatable collar, to actuate movement of introducer sheath relative to catheter.

DETAILED DESCRIPTION

Referring firstly toFIG.1there is shown components of a delivery catheter system generally designated10located within the aorta12of a patient. The features of the aorta include the ascending aorta14, the arch of aorta16, the descending aorta18, the left and right coronary arteries20,22, the brachiocephalic artery24, the left common carotid artery26and the left subclavian artery28. Not shown is the aortic valve which is to be replaced.

The delivery catheter system10includes catheter30and an embolic filter32. In the illustrated embodiment, the catheter may be considered to be a TAVI delivery catheter, and the embodiment is described with reference to a TAVI procedure. It will be appreciated, however, that in alternative embodiments the catheter may be used for different valve replacement procedures, or may be used in the placement of an intravascular stent.

The TAVI delivery catheter30may, by way of illustrative example only, correspond to the Medtronic EnVeo PRO™ delivery catheter system. The TAVI delivery catheter30includes an elongate catheter body31having a distal tip33. The TAVI delivery catheter30further includes a capsule (not shown) containing a replacement valve. The filter32is provided circumferentially around an outer surface of the TAVI delivery catheter30and extends across the annulus defined the between the TAVI delivery catheter30and the wall34of the ascending aorta14. The filter32is configured so as to be able to conform to the wall34of the ascending aorta14and thus provide required sealing characteristics against the wall of ascending aorta14. The filter32is provided with a high porosity membrane that doesn't restrict blood flow but at the same time provides the desired filtering characteristics to capture any debris36that may be dislodged by the TAVI procedure.

In the embodiment shown, the filter32is positioned in the ascending aorta14downstream of the left and right coronary arteries20,22and upstream of the arch of aorta16. Any debris36that may be dislodged by the TAVI procedure is thus captured by the filter32and prevented from reaching and entering the brachiocephalic artery24, the left common carotid artery26and/or the left subclavian artery28. It will be appreciated that the filter32may alternatively be positioned in the arch of the aorta14and downstream of the left and right coronary arteries20,22and upstream of the brachiocephalic artery24, the left common carotid artery26and/or the left subclavian artery28. In some arrangements, it will be appreciated that the filter32may be arranged downstream of the left and right coronary arteries20,22in the arch of the aorta14so as to cover the brachiocephalic artery24, the left common carotid artery26and/or the left subclavian artery28.

It will be appreciated thatFIG.1shows the filter32in a deployed state. The filter32is initially provided in an un-deployed or collapsed state. Although not illustrated, TAVI delivery catheter30and the collapsed filter32may be covered by an external catheter. The external catheter acts as a sheath or sleeve that maintains the filter32in the collapsed state during advancement of the TAVI delivery catheter30through the vasculature of the patient. Upon delivery of the replacement valve, i.e. upon positioning of the replacement valve in the desired location within the aorta12of a patient, the filter32can be moved to the deployed state. This may be achieved by, for example, by relative movement between the TAVI delivery catheter30and the external catheter in a first direction so as to uncover the filter32. The filter32may then move from the collapsed state to the deployed state, for example via shape memory material portions of the filter32.

The embolic filter32is formed from a support frame38. The support frame38may be formed from a shape memory material, for example a shape memory alloy or shape memory polymer. In each of the embodiments discussed herein, the shape memory material is nitinol, but it will be appreciated that any suitable shape memory material may be used. The filter32also includes a porous polymeric membrane40covering the support frame. The polymeric membrane40may comprise a biocompatible porous fabric having a pore size of between 100 and 200 nanometers.

With the filter32deployed and extending across the aforementioned annulus between the TAVI delivery catheter30and the wall34of the ascending aorta14, the TAVI procedure can be conducted. As noted above, any debris36that is be dislodged by the TAVI procedure is thus captured by the filter32and prevented from reaching and entering the brachiocephalic artery24, the left common carotid artery26and/or the left subclavian artery28. Once the TAVI procedure has been completed, and prior to the withdrawal of the TAVI delivery catheter30from the vasculature of the patient, the filter32is retrieved or moved back to its un-deployed or collapsed state from its deployed state while still retaining any debris36that may have been collected. Movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by, for example manipulation or movement of the sheath or sleeve back to its initial position.

Once the TAVI procedure has been completed, and prior to the withdrawal of the delivery catheter30from the vasculature of the patient, the filter32is retrieved while still retaining any debris36that may have been collected. Put another way, the filter32is moved back to its un-deployed or collapsed state from its deployed state while still retaining any debris36that may have been collected. Movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by relative movement between the TAVI delivery catheter30and the external catheter in a second direction, opposite to the first direction. Put another way, movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by movement of the sheath back to its initial position.

Referring now toFIGS.2and3there is shown an embodiment of a delivery catheter system generally designated110.

The delivery catheter system110includes a catheter30having an elongate body. Although not illustrated, the catheter30may be positioned within an introducer sheath of a delivery device. An embolic filter32is integrated with the catheter30. The embolic filter32is deployable from the catheter30prior to the delivery of an article or prosthesis in a patient's vasculature and retrievable to the catheter30after delivery of said article. It will be appreciated that the delivery catheter system110may be used for a range of different purposes, and the article or prosthesis being delivered will vary accordingly. The delivery catheter system110may be used to deliver a replacement valve place a stent in a patient's vasculature, and as such the article may be a valve or a stent, for example.

In the arrangement shown, the embolic filter32is connected to a releasable fastener56. The releasable fastener56is configured to releasably engage the catheter30so as to releasably attach the embolic filter32to the capsule35.

Relative movement between the catheter30and the capsule35in a first direction, e.g. a retraction of the catheter30, enables the embolic filter32to move from a collapsed state, whereupon the embolic filter32is retained closely to the body31of the catheter30, to a deployed state where the embolic filter32extends from the body31of the catheter30and, in use, into contact with an inner wall of a patient's vasculature. The filter32may then move from the collapsed state to the deployed state, for example via one or more shape memory portions of the filter32. The support frame38may be formed from a shape memory material, for example a shape memory alloy or shape memory polymer. In each of the embodiments discussed herein, the shape memory material is nitinol, but it will be appreciated that any suitable shape memory material may be used. The filter32also includes a porous polymeric membrane40covering the support frame. The polymeric membrane40may comprise a biocompatible porous fabric having a pore size of between 100 and 200 nanometers.

The delivery catheter system110is configured such that relative movement between the catheter30and the capsule35in a first direction beyond a predetermined distance causes the releasable fastener56to disengage from the capsule35. Put another way, the delivery catheter system110is configured such that retraction of the catheter30and/or advancement of the capsule35beyond a predetermined distance causes the releasable fastener56to disengage from the capsule35.

The delivery catheter system110is configured such that relative movement between the catheter30and the capsule35in a second direction, opposite to the first direction, beyond a predetermined distance causes the releasable fastener56to engage the capsule35. Put another way, the delivery catheter system110is configured such that extension/advancement of the catheter30and/or retraction of the capsule35beyond a predetermined distance causes the releasable fastener56to engage from the capsule35.

In the arrangement shown, the embolic filter32is connected to a resilient fastener56, e.g. a resilient clip such as a c-clip or a resilient coil. The resilient fastener56is urged into engagement with the body of the capsule35in a first, e.g. retracted, position. Urging of the resilient fastener56into engagement with the capsule35works to releasably attach the embolic filter32to the capsule35. In a second, e.g. advanced, position, the resilient fastener56expands into an internal groove58on the catheter30. This results in the resilient fastener56disengaging from the capsule35. At this point the embolic filter32is completely deployed. Disengaging or decoupling of the resilient fastener56(i.e. the embolic filter32) when the embolic filter32is deployed enables the capsule35to be advanced independently of the embolic filter32.

When the capsule35is retracted, it abuts against the resilient fastener56. The catheter30comprises an abutment surface60configured and arranged to abut against the resilient fastener56when the catheter30is retracted from a position beyond the second, advanced, position past said second, advanced position. The abutment surface60moves the resilient fastener56along a tapered surface62of the internal groove58so as to be urged into engagement with the capsule35. This works to releasably attach the embolic filter32to the capsule35. This, in turn, enables all of the delivery catheter system110to be removed from a patient.

The embodiment ofFIGS.2and3ensures that the embolic filter32is deployed before delivery of an article, e.g. a valve prosthesis. Put another way, the embodiment ofFIGS.2and3ensures that the embolic filter32is deployed before the capsule35is advanced. Following deployment of the embolic filter32, the capsule35can then be moved back and forward without limitations. In that way it doesn't change the way a procedure is usually made. The capsule35can move forward independently, but when the capsule35is retracted, it also urges the resilient fastener56into engagement with the capsule35.

The delivery catheter system110includes a deflecting member45. The deflecting member45is attached to an internal surface of the catheter30. The deflecting member45is configured to adjust the position of the catheter30(i.e. of the distal tip33) within the vasculature of a patient. It will be appreciated that although not illustrated, the deflecting member45may be utilised any of the delivery catheter systems illustrated inFIGS.4to8and or may be utilised in the introducer sheath of the introducer device illustrated inFIGS.9to12.

Although not illustrated, the deflecting member is attached to a control member (e.g. a handle or collar of a delivery device or another device) so as to be controlled by a physician to steer the external catheter within a patient's vasculature. The control member is configured to manipulate the deflecting member45so as to adjust the position of the catheter30within the vasculature of a patient, in use.

In the arrangement shown, the deflecting member is elongate wire, but it will be appreciated that any suitable arrangement for adjusting the position of the catheter30(i.e. of the distal tip33) within the vasculature of a patient may be used. The deflecting member45may be provided within a cover, e.g. an elongate tubular cover, within the catheter30.

The deflecting member may be attached, e.g. welded, to the catheter30. In such arrangements, it will be appreciated that the deflecting member45will be positioned within the catheter30so as to not to interfere with the embolic filter32e.g. when the embolic filter is in the collapsed state within the external catheter. Put another way, it will be appreciated that the deflecting member45will be attached (and terminate) at a position within the catheter30so as to not to interfere with the embolic filter32e.g. when the embolic filter is in the collapsed state within the external catheter.

Referring now toFIGS.4and5there is shown an embodiment of a delivery catheter system generally designated210.

The delivery catheter system210includes a catheter30having an elongate body. In the arrangement shown, the catheter30is positioned within an external tube or catheter42. It will be understood that the external tube or catheter may be an introducer sheath42of an introducer device (as is discussed in more detail below). The introducer sheath42has an elongate body. The catheter30is positioned within the elongate body of the introducer sheath42. An embolic filter32is integrated with the catheter30. The embolic filter32is deployable from the introducer sheath42prior to the delivery of an article in a patient's vasculature and retrievable to the introducer sheath42after delivery of said article. It will be appreciated that the delivery catheter system210may be used for a range of different purposes, and the article being delivered will vary accordingly. The delivery catheter system may be used to place a replacement valve or a stent in a patient's vasculature, and as such the article may be a valve or a stent, for example. The delivery catheter system may be used for a transcatheter aortic valve implantation, and as such the article may be a replacement valve. Alternatively, the delivery catheter system may be used for any suitable purpose.

Relative movement between the introducer sheath (i.e. an external catheter)42and the catheter30in a first direction, e.g. a retraction of the introducer sheath42, enables the embolic filter32to move from a collapsed state, whereupon the embolic filter32is retained closely to the body of the catheter30, to a deployed state where the embolic filter32extends from the body31of the catheter30and, in use, into contact with an inner wall of a patient's vasculature. The filter32may then move from the collapsed state to the deployed state, for example via one or more shape memory portions of the filter32. The support frame38may be formed from a shape memory material, for example a shape memory alloy or shape memory polymer. In each of the embodiments discussed herein, the shape memory material is nitinol, but it will be appreciated that any suitable shape memory material may be used. The filter32also includes a porous polymeric membrane40covering the support frame. The polymeric membrane40may comprise a biocompatible porous fabric having a pore size of between 100 and 200 nanometers.

In the embodiment shown, the introducer sheath42is configured (i.e. sized) to be capable of receiving a delivery catheter system (i.e. a catheter30) therethrough. The delivery catheter system30may be a transcatheter aortic valve implantation (TAVI) delivery catheter, a stent delivery catheter, a tool delivery catheter, or may delivery any other valve to a patient.

The catheter30has an elongate catheter body31having a distal tip33and a capsule35containing a deliverable article such as a stent or a replacement valve. The embolic filter32is connected to the catheter30at or near a distal tip33thereof. The embolic filter32may be connected to the catheter30by adhesive, sewing, crimping, thermobonding or any other suitable attachment arrangement. In the arrangement shown, the embolic filter32is positioned distal to (i.e. on the distal side of) the capsule35, when the capsule35is in the retracted position. Put another way, when the capsule35is in the retracted position, the capsule35is positioned within the catheter30. When the capsule35is in the retracted position, the capsule35is positioned within the introducer sheath42.

With the filter32deployed and extending across the aforementioned annulus between the catheter30and the wall34of the aorta14, the capsule35is advanced along the patient's vasculature so that the procedure can be conducted. Any debris36that is be dislodged by the procedure is thus captured by the filter32and prevented from reaching and entering the descending aorta18, brachiocephalic artery24, the left common carotid artery26and/or the left subclavian artery28.

Once the procedure has been completed, the article catheter30is retrieved. Prior to the withdrawal of the external catheter42from the vasculature of the patient, the filter32is retrieved while still retaining any debris36that may have been collected. Put another way, the filter32is moved back to its un-deployed or collapsed state from its deployed state while still retaining any debris36that may have been collected. Movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by relative movement between the external catheter42and the catheter30in a second direction, opposite to the first direction. This movement may be considered to be an extension or advancement of the external catheter42. Put another way, movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by movement of the external catheter42back to its initial position.

Referring now toFIGS.6to8there is shown an embodiment of a delivery catheter system generally designated310.

The delivery catheter system310includes a catheter30having an elongate body. The delivery catheter system310includes an internal catheter having an elongate body. In the arrangement shown, the catheter30is positioned within an external tube or catheter42. It will be understood that the external tube or catheter may be an introducer sheath42of an introducer device (as is discussed in more detail below). The introducer sheath42has an elongate body. The catheter30is positioned within the elongate body of the introducer sheath42.

An embolic filter32is integrated with the catheter30. The embolic filter32is deployable from the introducer sheath42prior to the delivery of an article in a patient's vasculature and retrievable to the introducer sheath42after delivery of said article. It will be appreciated that the delivery catheter system310may be used for a range of different purposes, and the article being delivered will vary accordingly. The delivery catheter system may be used to place a replacement valve or a stent in a patient's vasculature, and as such the article may be a valve or a stent, for example. The delivery catheter system may be used for a transcatheter aortic valve implantation, and as such the article may be a replacement valve. Alternatively, the delivery catheter system may be used for any suitable purpose.

Relative movement between the introducer sheath (i.e. an external catheter)42and the catheter30in a first direction, e.g. a retraction of the introducer sheath42, enables the embolic filter32to move from a collapsed state, whereupon the embolic filter32is retained closely to the body of the catheter30, to a deployed state where the embolic filter32extends from the body of the catheter30and, in use, into contact with an inner wall of a patient's vasculature. The filter32may then move from the collapsed state to the deployed state, for example via one or more shape memory portions of the filter32. The support frame38may be formed from a shape memory material, for example a shape memory alloy or shape memory polymer. In each of the embodiments discussed herein, the shape memory material is nitinol, but it will be appreciated that any suitable shape memory material may be used. The filter32also includes a porous polymeric membrane40covering the support frame. The polymeric membrane40may comprise a biocompatible porous fabric having a pore size of between 100 and 200 nanometers.

In the embodiment shown, the introducer sheath42is configured (i.e. sized) to be capable of receiving a delivery catheter system (i.e. a catheter30) therethrough. The delivery catheter system may be a transcatheter aortic valve implantation (TAVI) delivery catheter, a stent delivery catheter, a tool delivery catheter, or may delivery any other valve to a patient.

The catheter30has an elongate catheter body31having a distal tip33and a capsule35containing a deliverable article such as a stent or a replacement valve. The embolic filter32is connected to the catheter30at or near the distal tip33thereof. The embolic filter32may be connected to the catheter30by adhesive, sewing, crimping, thermobonding or any other suitable attachment arrangement.

In the arrangement shown, the embolic filter32is connected to the delivery catheter30proximal to (i.e. on a proximal or downstream side of) the capsule35, when the capsule35is in the retracted position. Put another way, when the capsule35is in the retracted position, the capsule35protrudes from the catheter30and the introducer sheath42.

In this arrangement, the external catheter42and the delivery catheter30do not extend over the capsule35. Put another way, the capsule35is oversized relative to the delivery catheter30such that the capsule35cannot extend along said delivery catheter30. This arrangement enables the diameter of the delivery catheter system310, i.e. the external catheter42, to be substantially equal to the external diameter of the capsule35.

Once the procedure has been completed, the article catheter30is retrieved. Prior to the withdrawal of the external catheter42from the vasculature of the patient, the filter32is retrieved while still retaining any debris36that may have been collected. Put another way, the filter32is moved back to its un-deployed or collapsed state from its deployed state while still retaining any debris36that may have been collected. Movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by relative movement between the external catheter42and the catheter30in a second direction, opposite to the first direction. This movement may be considered to be an extension or advancement of the external catheter42. Put another way, movement of the filter32back to its un-deployed or collapsed state from its deployed state may be achieved by movement of the external catheter42back to its initial position.

Referring now toFIGS.9to12there is shown an embodiment of an introducer device48.

The introducer device48includes an introducer sheath42. The introducer sheath42, or external catheter, holds the vessel (i.e. the vasculature of a patient) open so as to enable practitioners to insert other tools safely into the area of interest. Instead of inserting each tool within the skin opening, the tools are removed and inserted via the introducer sheath which minimizes the blood loss, minimizes skin damage and helps to deliver the tools at the right location. It will be appreciated that the introducer device48may be used in combination with any of the delivery catheter systems illustrated inFIGS.1to8.

The introducer device48includes a control member50. The control member50is provided to actuate movement (i.e. extension and retraction) of the introducer sheath42relative to the catheter30. The control member50may be provided in the form of a handle or collar52that is rotatable so as to actuate movement of the introducer sheath42relative to the catheter30. In alternative arrangements, however, it will be appreciated that any suitable control member may be provided to actuate movement of the introducer sheath42relative to the catheter30.

The introducer device48includes an upstream inlet54for receiving a catheter30therein to enable said catheter30to be delivered (i.e. positioned) at the desired location. Although not illustrated, the delivery device48and/or the introducer sheath42may be provided with a valve arrangement to prevent the leakage of blood from the inlet54.

The introducer device includes an embolic filter32deployable from a distal end of the introducer sheath42, as shown inFIG.10. The embolic filter32may be deployable from the introducer sheath42as disclosed above.

FIG.11shows the introducer device48inserted in the femoral access. Once the introducer sheath42has been inserted, and the embolic filter32has been deployed, a catheter30can be advanced so as to protrude from the distal tip46of the introducer sheath42(as is illustrated inFIG.8). It will be appreciated that any kind of catheter30can be inserted through the introducer device48. The introducer sheath42is able to remain in a patient's vasculature such that several tools can be brought to the annulus. For example, if a valve prosthesis (such as an aortic valve prosthesis) has been wrongly released, the catheter30can be removed and a second catheter30can be inserted while the introducer sheath42stays in position in the vasculature of the patient.