Stent delivery apparatus

Abstract

The invention relates to a stent delivery apparatus (1) comprising: a proximal handle (2), a catheter assembly (3) comprising: an outer sheath (31; an inner elongated arrangement (32) connected to said handle (2), said arrangement comprising an inner shaft (322), in particular a hollow inner shaft (322), and an outer tube (321) mounted coaxially in translation; wherein at least one of the inner shaft (322) and outer tube (321) is able to be actuated in translation by a second sliding mechanism (6) having a second control member (61), in particular a second knob (61) mounted in rotation on said handle (2); wherein the inner elongated arrangement (32) further comprises a distal clamp (7) adapted to hold or release a stent (4), said clamp (7) being formed by an inner member (72) and an outer annular member (71) mounted coaxially in translation, wherein in a hold position a proximal part of the stent (4) is held between an outer surface of the inner member (72) and an inner surface of the outer annular member (71) and wherein a relative translation between the inner member (72) and the outer annular member (71) allows the release of the proximal part of the stent (4); wherein the stent delivery apparatus (1) is configured such that an actuation of the second control member (61) induces, in a first functioning mode, a translation in unison of the inner shaft (322) and the outer tube (321) so as to push distally or pull proximally the proximal part of the stent (4) relative to the outer sheath (31), and, in a second functioning mode different from the first functioning mode, the relative translation between the inner member (72) and the outer annular member (71), allowing the release of the stent (4).

Description

STENT DELIVERY APPARATUSTechnical Field

[0001] The present invention relates to a stent delivery apparatus and a method for operating said apparatus.Background Art

[0002] It is known in the prior art to have a stent delivery apparatus with a clamp mechanism for holding the stent. However, such an apparatus does not allow for efficient re-sheathing of the stent in case an operator decides to relocate the position of the stent delivery. In particular, during re-sheathing, the stent, undergoing traction, is accidentally released. European Patent Application EP2932943A1 discloses a stent delivery system for the treatment of intracranial aneurysms, which includes a stent holding assembly having a breakable coupling configured to maintain the axial position of a constraining member relative to a core member. However, in cases involving self-expandable stents with high radial force such as aortic stent, or when delivering the stent through tortuous vasculature, a more robust clamping mechanism is required to prevent premature displacement of the stent during delivery. EP2932943A1 does not provide a specific disclosure that addresses or resolves this issue. Furthermore, EP2932943A1 does not disclose any means for performing a push-pull motion that enables precise stent deployment conforming to the vessel morphology, without requiring movement of the handle itself until deployment is complete.Aims of the Invention

[0003] The invention aims to provide a solution to at least one drawback of the teaching provided by the prior art.

[0004] More specifically, the invention aims to ensure a safe re-sheath operation of the stent and / or a safe repositioning of the stent. The invention additionally aims to enable a push-pull motion in the stent delivery system during stent deployment.Summary of the Invention

[0005] For the above purpose, the invention is directed to a stent delivery apparatus and method for delivering a stent in a patient.

[0006] A stent delivery apparatus comprises a proximal handle and a catheter assembly. The catheter assembly comprises an outer sheath. Preferably, the outer sheath is connected to the proximal handle and is able to be actuated in translation by a first sliding mechanism having a first control member, in particular a first knob mounted inrotation on the handle. The catheter assembly also comprises an inner elongated arrangement connected to the handle. This arrangement comprises an inner shaft, in particular a hollow inner shaft, and an outer tube mounted coaxially in translation. At least one of the inner shaft and outer tube is able to be actuated in translation by a second sliding mechanism having a second control member, in particular a second knob mounted in rotation on the handle. The inner elongated arrangement further comprises a distal clamp adapted to hold or release a stent. This clamp is formed by an inner member and an outer annular member mounted coaxially in translation. In a hold position, a proximal part of the stent is held between the outer surface of the inner member and the inner surface of the outer annular member. A relative translation between the inner member and the outer annular member allows the release of the proximal part of the stent. The stent delivery apparatus is configured such that an actuation of the second control member induces:- in a first functioning mode, a translation in unison of the inner shaft and the outer tube so as to push distally or pull proximally the proximal part of the stent relative to the outer sheath, and- in a second functioning mode different from the first functioning mode, the relative translation between the inner member and the outer annular member, allowing the release of the stent.

[0007] The outer sheath is preferably connected to the proximal handle. However, there may exist alternative embodiments of the invention wherein the outer sheath is not connected to said handle. For example, the outer sheath may be actuated by hand when it is not connected to the proximal handle.

[0008] A distal end region of the outer tube may be attached to or comprise the outer annular member, and a distal end region of the inner shaft may be attached to or comprise the inner member.

[0009] The proximal handle may comprise a safety mechanism configured, in a first operating mode, to prevent the release of the stent, and, in a second operating mode, to allow the release of the stent. The safety mechanism can be configured to prevent the relative translation between the inner member and the outer annular member in the first operating mode, preferably when the second control member induces the translation of the outer tube and the inner shaft.

[0010] An elastic element may be connected to the inner shaft and the outer tube to bias the relative translation between the inner member and the outer annular member, thereby exerting a holding pressure on the stent. The stent delivery apparatus ispreferably configured so that the elastic element is prestressed to press the proximal end of the stent, which may be positioned between the inner member and the outer annular member. Preferably, the elastic element is comprised in the stent delivery apparatus in combination with the safety mechanism. Generally, the elastic element may be selected from a group of spring, elastomeric material, bellow structure, corrugated plate, compressible foam, tensioned elastic cord, and shape memory alloy. The elastic element is preferably a spring.

[0011] The first sliding mechanism may comprise a first slider, and the second sliding mechanism may comprise a second slider. Each slider may be positioned in the proximal handle.

[0012] The first slider may comprise an outer contour with splines adapted to cooperate with corresponding splines formed on an inner surface of the first control member, in particular the first knob, for transforming a rotation of the first control member, in particular the first knob, into a translation of the first slider and the outer sheath. Similarly, the second slider may comprise an outer contour with splines adapted to cooperate with corresponding splines formed on an inner surface of the second control member, in particular the second knob, for transforming a rotation of the second control member, in particular the second knob, into a translation of the second slider and at least one of the inner shaft and outer tube.

[0013] The stent delivery apparatus may be configured so that the first slider and the second slider cannot overlap during their displacement.

[0014] The stent delivery apparatus may further comprise a first and a second abutment adapted to limit the stroke of the outer tube in the distal direction, preferably via a sleeve, and the stroke of the second slider in the distal direction, respectively.

[0015] In a preferred embodiment, the inner shaft is attached or rigidly connected to the second slider and is able to be directly actuated in translation by said slider, and the outer tube is able to be indirectly actuated in translation by said slider via the elastic element.

[0016] In another preferred embodiment, the safety mechanism is configured such that when a coupling control element of said mechanism is set in the first operating mode, it allows the translation in unison of the inner shaft and the outer tube as long as the second slider is not restricted by the second abutment in the distal direction. When the coupling control element is set to the second operating mode, it allows both the translation in unison of the inner shaft and the outer tube as long as the outer tube is not restricted by the first abutment in the distal direction, preferably via the sleeve, and the release ofthe stent while the stroke of the outer tube is restricted in the distal direction, preferably via the sleeve, by the first abutment, and the inner shaft is displaced in the distal direction by the second slider.

[0017] The coupling control element may comprise or consist of a straightening strip adapted to be engaged in a deformable protrusion extending from the second slider in the distal direction.

[0018] The first slider may be attached or rigidly connected to a proximal end region of the outer sheath.

[0019] The inner shaft may be hollow and may comprise or consist of a tube extending from the second slider to the outer annular member.

[0020] The inner shaft may further comprise a clamp abutment, in particular said clamp abutment comprising or consisting of a collar or flange.

[0021] The catheter assembly may further comprise a central shaft, in particular a central tube, and a distal tip connected to said central shaft. The distal tip defines, with a distal portion of the outer sheath, a compartment for housing the stent before its release, wherein the central shaft is positioned in the hollow inner shaft, in particular in the tube of the hollow inner shaft.

[0022] For the above purpose, the invention is directed to a method for delivering a stent in a patient. The method comprises the steps of providing a stent delivery apparatus, configuring the stent delivery apparatus, loading the stent, partially deploying the distal end of the stent, and releasing the proximal end of the stent to ensure its full deployment.

[0023] In the step of providing a stent delivery apparatus, the apparatus comprises a proximal handle and a catheter assembly. The catheter assembly includes an outer sheath. Preferably, the outer sheath is connected to the proximal handle and is able to be actuated in translation by a first sliding mechanism having a first control member. Preferably, the first control member is a first knob mounted in rotation on the handle. The catheter assembly also comprises an inner elongated arrangement connected to the handle. The inner elongated arrangement includes an inner shaft, in particular a hollow inner shaft, and an outer tube mounted coaxially in translation. At least one of the inner shaft and outer tube is able to be actuated in translation by a second sliding mechanism having a second control member. Preferably, the second control member is a second knob mounted in rotation on the handle. The inner elongated arrangement comprises a distal clamp adapted to hold or release the stent. The clamp is formed by an inner member and an outer annular member mounted coaxially in translation. In a hold position, a proximal part of the stent is held between an outer surface of the inner member and aninner surface of the outer annular member. A relative translation between the inner member and the outer annular member allows the release of the proximal part of the stent. The catheter assembly further comprises a central shaft, in particular a central tube.

[0024] In the step of configuring the stent delivery apparatus, the apparatus is configured such that an actuation of the second control member induces, in a first functioning mode, a translation in unison of the inner shaft and the outer tube so as to push distally or pull proximally the proximal part of the stent relative to the outer sheath, and, in a second functioning mode different from the first functioning mode, the relative translation between the inner member and the outer annular member, allowing the release of the stent. A distal tip connected to the central shaft defines, with a distal portion of the outer sheath, a compartment for housing the stent before its release, wherein the central shaft is positioned in the inner shaft, in particular in the hollow inner shaft. The proximal handle may comprise a safety mechanism configured to prevent the release of the stent in a first operating mode and to allow the release of the stent in a second operating mode. The safety mechanism is configured to prevent the relative translation between the inner member and the outer annular member in the first operating mode, preferably when the second control member induces the translation of the outer tube and the inner shaft.

[0025] In the step of loading the stent, the stent is loaded into the compartment, and the stent is covered with the distal portion of the outer sheath.

[0026] In the step of inserting the catheter assembly into the patient, the stent is positioned at a target location within the patient. In the step of partially deploying the distal end of the stent, the outer sheath is moved in the proximal direction, preferably by rotating the first knob. Finally, the proximal end of the stent is released to ensure full deployment of the stent by moving the inner shaft in the distal direction, preferably by rotating the second knob, while the stroke of the outer tube is restricted in the distal direction. This ensures relative translation between the inner member and the outer annular member, allowing the release of the stent.

[0027] This method ensures precise and controlled deployment of the stent, minimizing the risk of misplacement and enhancing patient outcomes.

[0028] The method may further comprise the step of exerting a holding pressure on the stent with an elastic element which is connected to the inner shaft and to the outer tube in order to bias the relative translation between the inner member and the outer annular member, wherein a proximal end of the stent is positioned between the inner member and the outer annular member, and the apparatus is configured so that the elastic element is prestressed in order to press a proximal end of the stent.

[0029] The method may further comprise the step of setting the safety mechanism in the first operating mode, prior to the releasing.

[0030] The method may further comprise the step of longitudinally compressing the stent by moving the inner elongated arrangement of the catheter assembly in the distal direction, preferably through rotating the second knob.

[0031] The method may further comprise the step of moving the outer sheath in the distal direction in order to re-sheath the stent.

[0032] The method may further comprise the step of moving the inner elongated arrangement of the catheter assembly in the proximal direction, in particular through rotating the second knob, in order to re-sheath the stent.Brief Description of Drawings

[0033] Aspects of the disclosure will now be described in more detail with reference to the appended drawings, wherein same reference numerals illustrate same features.

[0034] Figure 1 discloses a cross section of a stent delivery apparatus according to the invention.

[0035] Figure 2 shows stages in the deployment of stent 4 in a substantially rectilinear vessel.

[0036] Figure 3 shows an enlarged views of the stent delivery apparatus shown in Figure 2 for stages 2 and 4.

[0037] Figure 4 shows stages in the deployment of stent 4 in a vessel showing a partially enlarged section.

[0038] Figure 5 illustrates a re-sheath operation (a.k.a. resheathing).

[0039] Figure 6 shows an alternative re-sheath operation.

[0040] The reference list:Detailed description

[0041] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may however be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodimentsare provided for purposes of illustration.

[0042] Figure 1 discloses a first embodiment of a stent delivery apparatus 1. Said apparatus 1 comprises a proximal handle 2 and a catheter assembly 3. The catheter assembly 3 comprises an outer sheath 31 connected to the proximal handle 2. The outer sheath 31 is able to be actuated in translation by a first sliding mechanism 5 having a first knob 51 mounted in rotation on said handle 2. In this description, the side where said handle 2 of the stent delivery apparatus 1 is located is defined as “proximal”, and the side where the stent is loaded is defined as “distal”.

[0043] It should be understood that the term “first sliding mechanism” as used herein may also be referred to as an “outer sliding mechanism” or an “outer sheath sliding mechanism”. These terms may be used interchangeably in the description and in the claims. Similarly, the term “first control member” may also be referred to as an “outer control member” or an “outer sheath control member”, and the term “first knob” may also be referred to as an “outer knob” or an “outer sheath knob”. These alternative expressions are intended to describe the same structural features, unless the context clearly indicates otherwise.

[0044] The catheter assembly 3 further comprises an inner elongated arrangement 32, which includes a hollow inner shaft 322 and an outer tube 321 mounted coaxially in translation. The inner elongated arrangement 32 also comprises a distal clamp 7 designed to hold or release a stent 4. The clamp 7 is formed by an inner member 72 and an outer annular member 71 mounted coaxially in translation. In the hold position, the stent 4 is held between the outer surface of the inner member 72 and the inner surface of the outer annular member 71. The distal end region of the outer tube 321 comprises the outer annular member 71 , while the distal end region of the inner shaft 322 comprises the inner member 72. Preferably, the distal end region of inner shaft 322 further comprises a clamp abutment (clamp pusher) 73 so that the proximal part of the stent 4 can be axially prepositioned within the clamp 7 during the loading phase of the stent 4 and be secured from moving towards the handle direction during the stent releasing step.

[0045] The catheter assembly further comprises a central shaft 33, in particular a central tube 33, and a distal tip 34 connected to said central shaft 33. The distal tip 34 defines, with a distal portion of the outer sheath 31 , a compartment 35 for housing the stent 4 before the release of the stent 4. The central shaft 33 is positioned in the hollow inner shaft 322 and also extends through the handle 2.

[0046] An elastic element 325, preferably a spring element 325, is connected to boththe inner shaft 322 and the outer tube 321 to bias the relative translation between the inner member 72 and the outer annular member 71 , thereby exerting a holding pressure on the stent 4. By continuously applying a proximally directed force to the inner shaft via the elastic element 325, the holding pressure on the stent 4 can be maintained. This configuration enhances the ability of the holding mechanism to withstand the substantial radial force exerted by self-expandable stents. As a result, a more robust clamping mechanism with sufficient holding force can be expected to prevent premature displacement of the stent during delivery. Generally, the elastic element 325 may be selected from a group of spring, elastomeric material, bellow structure, corrugated plate, compressible foam, tensioned elastic cord, and shape memory alloy. The elastic element 325 is preferably a spring. The relative translation between the inner member 72 and the outer annular member 71 allows, in a first step, the release of the holding pressure on the stent 4, and, in a second step, the release of the stent 4, preferably while the clamp abutment 73 pushes out the stent 4. Upon the release of the stent 4, the relative translation between the inner shaft 322 and the outer tube 321 reaches a certain stroke corresponding to the opening of the clamp 7. The stent delivery apparatus 1 is configured so that the relative translation is induced by the actuation of a second knob 61 located on the handle 2.

[0047] It should be understood that the term “second sliding mechanism” as used herein may also be referred to as an “inner sliding mechanism” or an “inner elongated arrangement sliding mechanism”. These terms may be used interchangeably in the description and in the claims. Similarly, the term “second control member” may also be referred to as an “inner control member” or an “inner elongated arrangement control member”, and the term “second knob” may also be referred to as an “inner knob” or an “inner elongated arrangement knob”. These alternative expressions are intended to describe the same structural features, unless the context clearly indicates otherwise.

[0048] A safety mechanism 9 may be provided in the handle 2 to prevent any inadvertent opening of the clamp 7 and release of the stent 4. A safety mechanism 9 can be set in two states (a.k.a. configuration). In a first operating mode illustrated in Figure 1 , the safety mechanism 9 prevents the release of the stent 4 through restricting the relative translation between the inner member 72 and outer annular member 71. In a second operating mode, the safety mechanism 9 allows the release the stent 4.

[0049] The stent delivery apparatus 1 is configured so that the second knob 61 ensures not only the control of the clamp 7 but also a translation in unison of the hollow inner shaft 322 and the outer tube 321 so as to push (i.e. move distally) or pull (i.e. moveproximally) the stent 4 relative to the outer sheath 31 .

[0050] The stent delivery apparatus 1 is also configured so that the first knob 51 ensures a translation of the outer sheath 31 so as to push / re-sheath (i.e. move distally) or pull (i.e. move proximally) the outer sheath 31 relative to the stent 4. Thanks to these configurations according to the invention, once stent deployment has been initiated, push- pull motion can be performed without moving the handle itself until deployment is complete. This enables precise stent deployment conforming to the vessel morphology by reducing the risk of inadvertently advancing the already apposed portion of the stent against the vessel wall, while allowing the self-expandable stent to properly exert its radial expansion force during deployment. As a result, the stent can be deployed so as to reach a sufficient inner diameter even in curved vascular regions or in vessels with a narrowed lumen, including those narrowed due to dissection.

[0051] The safety mechanism 9 comprises a control element, namely a straightening strip 91 , that is engaged in a deformable protrusion 92 extending from the second slider 62 in distal direction.

[0052] When the straightening strip 91 of the safety mechanism 9 is set in the first operating mode, in which the coupling control element 91 engages the deformable protrusion 92, the safety mechanism allows the simultaneous translation of the inner shaft 322 and the outer tube 321 as long as the second slider 62 is not restricted by a dedicated abutment 56 in the distal direction. In this first embodiment, the dedicated abutment 56 is formed by a proximal end surface portion of the first slider 61 . In the first operating mode, the straightening strip 91 is held in place by friction within an orifice located in the proximal end portion of the proximal handle 2.

[0053] The straightening strip 91 consists of an elongated rigid body 91 1 and a head 912. The head 912 is designed to be easily retracted by the operator and includes a portion that ensures frictional attachment within the orifice 93. Alternatively or in addition, a proximal portion of the elongated rigid body 911 can provide frictional retention. The elongated rigid body 911 is also designed to engage within a tunnel formed in the deformable protrusion 92. The distal extremity of the elongated rigid body 911 may be designed to prevent said body 911 from moving proximally further than the tunnel formed in the deformable protrusion 92. For instance, the distal extremity of the elongated rigid body 911 may comprise at least one lateral protrusion adapted to abut against a distal end portion of the deformable protrusion 92, thereby restricting the displacement of said body 911 in the proximal direction.

[0054] During use, when the second slider 62 moves, the deformable protrusion 92 slides around the elongated rigid body 91 1 , which remains fixed relative to the orifice 93 due to its releasable attachment to the handle 2. Consequently, they together form a rigid rod assembly. When the distal tip of the deformable protrusion 92 presses against its dedicated abutment 56, which is formed by the proximal end surface portion of the first slider 51 , the rod does not buckle. As a result, the second slider 62 is blocked in translation upon contact with its dedicated abutment 56. This measure and the fact that the outer tube 321 is in abutment against the first slider 52 prevents unintentional release of the proximal part of the stent 4, as the outer tube 321 and the inner shaft 322 are not moved independently from another, thereby ensuring that the elastic element 325 remains pretensioned to hold firmly the proximal part of the stent 4 in the clamp 7.

[0055] When the coupling control element 91 , namely the straightening strip 91 , is set in the second operating mode, namely the straightening strip 91 is retracted, the stent delivery apparatus 1 is set in an operating mode where the stent 4 can be released. Normally, the operator removes the straightening strip 91 when the stent 4 is almost fully deployed and ready to be freed. Indeed, when the distal end of the outer sheath 31 is reached at the distal end of the distal clamp 7, the first slider 52, has almost reached or reached its end stroke direction in a proximal direction. The end stroke is reached once the first slider 52 abuts against a stroke limiter 21 disposed between the first knob 51 and second knob 61 .

[0056] Before opening the clamp 7, any gap between the abutment 56 and the tip of the deformable protrusion 92 is minimized through a final displacement in unison of the inner shaft 322 and the outer tube 321 , preferably by pushing the second slider 62 in the distal direction. As the straightening strip 91 is retracted, the deformable protrusion 92 in absence of the elongated rigid body 911 , does not restrict the displacement of the second slider 62 towards the first slider 52. Indeed, the deformable protrusion 92 bends without opposing a significant resistance to the second slider 62. The distal end of the first slider 52 comprises an aperture 521 adapted to guide and receive the buckled deformable protrusion 92. The final displacement of the second slider 62 causing the buckling of the deformable protrusion 92 is limited and does not cause a significant displacement of the stent 4. Indeed, as the sent 4 is already almost entirely deployed in the patient, in particular a patient vessel 11 , the stent 4 remains anchored in the vessel 1 1 by friction and form fitting, even if the proximal end of the stent 4 undergoes a small translation induced by clamp 7 during this release preparation. In the second operating mode (sent release possible) of this embodiment, only the stroke of the outer tube 321 is restricted by acorresponding abutment 55 formed on a radially inner portion of the proximal end of the first slider 52.

[0057] Preferably, a spacer, in particular a sleeve 327, is present between the abutment 55 and an abutting flange 328 provided at a proximal end of the outer tube 321 . The use of a spacer having the form of a sleeve eases the design of the outer tube 321 as just an end flange is sufficient.

[0058] When the two following conditions are fulfilled: (a) the stroke abutting flange 328 of the outer tube 321 being restricted by its corresponding abutment 55, via the sleeve 327, and (b) the second slider 62 being still urged in the distal direction by the operator, the clamp 7 opens, releasing the proximal part of the stent 4.

[0059] During the opening of the clamp 7, the clamp inner member 72 (connected to the second slider 62 by means of the inner shaft 322) is further moved distally relative to the outer clamp annular member 71 (connected to the outer tube 321 whose displacement is restricted by the abutment 55). The opening of the clamp 7 is ensured by widening an annular gap between the clamp annular member 71 and the clamp inner member 72. Before the opening of the clamp 7 (when the clamp 7 is still retracted), the annular gap defines an annular cavity adapted to receive and hold the proximal end of the sent 4. Upon reaching a certain opening of the annular gap, the previously prestressed proximal end of the stent 4 elastically expands and is pushed further, preferably by clamp abutment 73. Then the stent 4 is entirely released until reaching its final position.

[0060] Figure 2 illustrates the stages in the deployment of stent 4 using a preferred embodiment of the stent delivery apparatus according to the present application in a substantially rectilinear vessel 11 . Before reaching stage S1 , the stent delivery apparatus 1 is loaded with the stent 4, which is placed in the compartment 35. The catheter assembly 3 is then inserted into the patient’s vessel 1 1 and pushed towards its target location for deployment.

[0061] At stage S1 , the catheter assembly 3 has reached its target position, aligning the stent 4 with the portion of the vessel 11 to be treated. From stage S1 to stage S2, the outer sheath 31 is retracted proximally (often referred to as “pulled”) until it reaches the end stroke of the first slider 52. The end stroke is reached when the first slider 52 abuts against a stroke limiter 21 located between the first knob 51 and the second knob 61 . The stroke limiter 21 may have an annular shape and comprises two opposing abutment surfaces.

[0062] From stage S2 to stage S3, the straightening strip 91 is retracted.

[0063] From stage S3 to stage S4, the second knob is turned to move the second slider 62 distally (a.k.a. push motion). Since the stroke of the outer tube 321 is restricted (via the sleeve 327) by the corresponding abutment 55 formed on the first slider 51 , a relative translation between the outer tube 321 and the hollow inner shaft 322 is induced. This action opens the clamp 7 and releases the stent 4, as shown in stage S4. It should be noted that in Figure 2 stage S1 , the position of the second slider 62 has been pre-set so that the deformable protrusion 92 abuts against the first slider 52, when the first slider 52 reaches its proximal end stroke defined by the stroke limiter 21. However, the prepositioning of the second slider 62 is arbitrary. Advantageously, in example disclosed in Figure 2, it ensures that once the outer sheath 31 is fully retracted, the actuation of the second knob 61 would ensures the triggering of the release phase of the stent 4. In an alternative pre-setting, a minimal unison push stroke may be desired before the opening of the clamp 7. In this case the prepositioning of the second slider 62 is slightly shifted proximally compared to the prepositioning of the second slider 62 show in Figure 2 stage S1 . In another configuration, the prepositioning of the second slider 62 could be set distally compared to the prepositioning of the second slider 62 show in Figure 2 stage S1 . These presetting can be selected depending on the length or type of the stent.

[0064] Once the stent 4 is released, the catheter assembly 3 can be removed by pulling the central tube 33. For this purpose, a holding means is provided at the proximal end of the central tube 33. The pulling the central tube 33 is not illustrated.

[0065] Figure 3 shows an enlarged views of the stent delivery apparatus shown in Figures 2 for stages S2 and S4.

[0066] Figure 4 illustrates the stages in the deployment of stent 4 using a preferred embodiment of the stent delivery apparatus according to the present application within a vessel 11 with a more complex shape, including an enlarged section. Similar to Figure 2, prior to reaching stage S1 , the stent delivery apparatus is loaded with the stent 4, which is placed in the compartment 35. The catheter assembly 3 is then inserted into the patient so that the stent 4 is positioned close to the target location within the patient vessel 11 to be treated.

[0067] From stage S1 to stage S2, the outer sheath 31 is partially retracted proximally, causing the distal end of the stent 4 to expand into the vessel 1 1 . However, due to the local curvature, it does not adequately cover the inner surface of the vessel 1 1 , especially in the enlarged section. In this case, the stent delivery apparatus 1 allows for the compression of the stent 4 so that it can conform to the inner wall shape of the vessel 11 . In this process, the proximal end of the stent 4 can be pushed using a combination ofthe outer tube 321 and the hollow inner shaft 322, while securely holding the stent in the clamp 7. As the first and second sliding mechanisms allow the first 52 and second 62 sliders to move independently relative to the handle, it is possible to perform pull and push motions of the outer sheath 31 and push and pull motions of the clamp 7 without accidentally releasing the partially deployed stent 4 in the vessel 11 Thanks to these configurations according to the invention, once stent deployment has been initiated, a push-pull motion can be performed smoothly without moving the handle itself until deployment is complete. This further reduces the risk of inadvertently advancing the already apposed portion of the stent against the vessel wall in regions of local curvature.

[0068] Stage S3 depicts the stent 4 after the distal shift (referred to as “push”) of the clamp 7, and in stage S4, the final release of the stent 4 is illustrated, which is comparable to the scenario presented in Figure 2.

[0069] In Figure 5, a re-sheathing operation as a preferred embodiment of the stent delivery apparatus 1 according to the present application is depicted. Stage S1 is performed in the same manner as in Figure 2. From stage S1 to stage S2, the outer sheath 31 is retracted proximally, often referred to as “pulled”. In stage S2, the operator decides to reload it into the compartment 35, enabling it to be deployed in an alternative location. Importantly, the stent delivery apparatus 1 allows for the re-sheathing of the stent 4 through a distal displacement (a.k.a. resheathing motion) of the outer sheath 31 .

[0070] Stage S3 illustrates a partial re-sheathing process. During the re-sheathing operation, a longitudinal traction force is applied to the stent 4. Thanks to the presence of the clamp 7, which securely holds the stent 4, the risk of accidental stent release is effectively prevented.

[0071] In Figure 6, a re-sheathing operation as a preferred embodiment of the stent delivery apparatus 1 according to the present application in another way is depicted, and stage S1 is carried out in the same manner as that shown in Figure 5. From stage S1 to stage S2 in Figure 6, the outer sheath 31 is retracted partially proximally. Figure 6 introduces an alternative method for re-sheathing the stent 4. The stent delivery apparatus enables the re-sheathing of the stent 4 through a proximal displacement of both the outer tube 321 and the hollow inner shaft 322 in unison, as illustrated in stages S3 and S4.

[0072] This re-sheathing process also induces a longitudinal traction force on the stent 4. Thanks to the presence of the clamp 7, which securely holds the stent 4, any accidental release of the stent is effectively prevented.

[0073] The first and second knobs, 51 and 61 , have a generally cylindrical shape withan outer surface designed to be handheld and an inner surface with splines that cooperate with a corresponding outer surface of the corresponding first 52 or second 62 slider. These knobs, 51 and 61 , along with the corresponding sliders, 52 and 62, are preferably designed to transform the rotation of the knob, 51 or 61 , into the translation of the slider, 52 or 62, and the outer sheath 31 or at least one of the inner shaft 322 and outer tube 321 . In other words, the first slider 52 may comprise an outer contour with splines adapted to cooperate with corresponding splines formed on an inner surface of the first control member 51 , in particular the first knob 51 , for transforming a rotation of the first control member 51 , in particular the first knob 51 , into a translation of the first slider 52 and the outer sheath 31 . Similarly, the second slider 62 may comprise an outer contour with splines adapted to cooperate with corresponding splines formed on an inner surface of the second control member 61 , in particular the second knob 61 , for transforming a rotation of the second control member 61 , in particular the second knob 61 , into a translation of the second slider 62 and at least one of the inner shaft 322 and outer tube 321.

[0074] In the first embodiment, the first slider 51 is connected to the outer sheath 31 , and they are illustrated as two distinct elements. Alternatively, these elements can be integrated into a single unit. The first embodiment employs a hand-driven spindle screw mechanism, which is depicted in Figures 1 to 6. However, it is worth noting that each of the sliding mechanisms 5 and 6 can be mechanically driven by an electric motor, electrically driven with a spool / plunger configuration, or hydraulically or pneumatically driven by a cylinder / piston arrangement in alternative embodiments. As another alternative embodiment to the spindle screw mechanism, a rack gear mechanism could also be considered.

[0075] The discussed embodiments demonstrate a series of mechanisms to ensure the synchronization of the different elements. Alternatively or additionally, position sensors can be provided to monitor and coordinate the various movements of the components. In combination with these sensors, at least two electric motors can be dedicated to actuating the outer sheath 31 , inner shaft 322, and outer tube 321 .

[0076] The safety mechanism 9 is advantageously illustrated with the use of a deformable protrusion 92. Alternatively, the coupling of the inner shaft 322 and the outer tube 321 to ensure a unison motion thereof or their disengagement (allowing the clamp 7 to open or close) can be ensured by other types of locking systems, such as a pin actuated transversely with regard to the displacement of the inner shaft 322 and the outer tube 321 . In a first operating mode, the pin engages in an aperture formed in both the inner shaft322 and the outer tube 321 , preventing any relative displacement between the inner shaft 322 and the outer tube 321 , thereby avoiding an accidental release of the stent 4. In a second operating mode, the pin is only engaged with the outer tube 321 , setting the stent delivery apparatus in mode to release the stent 4. This pin can be mechanically or electrically actuated by the operator via a button positioned on the handle.

[0077] The invention also relates to a method for delivering a stent 4 in a patient. Particular embodiments of said method are described hereinbelow.

[0078] In an embodiment, the method according to the invention comprises:- providing a stent delivery apparatus 1 comprising a proximal handle 2 and a catheter assembly 3, said catheter assembly 3 comprising:- an outer sheath 31 , preferably connected to said handle 2 and able to be actuated in translation by a first sliding mechanism 5 having a first control member 51 , in particular a first knob 51 mounted in rotation on said handle 2;- an inner elongated arrangement 32 connected to said handle 2, said arrangement comprising an inner shaft 322, in particular a hollow inner shaft 322, and an outer tube 321 mounted coaxially in translation; wherein at least one of the inner shaft 322 and outer tube 321 is able to be actuated in translation by a second sliding mechanism 6 having a second control member 61 , in particular a second knob 61 mounted in rotation on said handle 2; wherein the inner elongated arrangement 32 further comprises a distal clamp 7 adapted to hold or release the stent 4, said clamp 7 being formed by an inner member 72 and an outer annular member 71 mounted coaxially in translation, wherein in a hold position a proximal part of the stent 4 is held between an outer surface of the inner member 72 and an inner surface of the outer annular member 71 and wherein a relative translation between the inner member 72 and the outer annular member 71 allows the release of the proximal part of the stent 4;- a central shaft 33, in particular a central tube 33; wherein the stent delivery apparatus 1 is configured such that an actuation of the second control member 61 induces: in a first functioning mode, a translation in unison of the inner shaft 322 and the outer tube 321 so as to push distally or pull proximally the proximal part of the stent 4 relative to the outer sheath 31 , and, in a second functioning mode different from the first functioning mode, the relative translation between the inner member 72 and the outer annular member 71 , allowing the release of the stent 4; wherein a distal tip 34 connected to said central shaft 33 defines with a distal portion of the outer sheath 31 , a compartment 35 for housing the stent 4 before the release of the stent 4, wherein said central shaft 33 is positioned in the inner shaft 322, in particular in the hollow inner shaft 322, wherein the proximal handle 2 preferably comprises a safety mechanism 9 configured, in a first operating mode, toprevent the release of the stent 4, and, in a second operating mode, to allow the release of the stent 4, said mechanism being configured to prevent the relative translation between the inner member 72 and the outer annular member 71 in the first operating mode, preferably when the second control member 61 induces the translation of the outer tube 321 and the inner shaft 322;- loading the sent 4 into a compartment, in particular the compartment 35, and covering the compartment and the stent 4 with the distal portion of the outer sheath 31 ;- inserting the catheter assembly 3 into the patient so that the stent 4 is positioned at a target location within the patient;- at least partially deploying a distal end of the stent 4 by moving the outer sheath 31 in the proximal direction, preferably by rotating the first knob 51 ;- releasing a proximal end of the stent 4 to ensure the full deployment of the sent 4, by moving the inner shaft 322 in the distal direction, preferably by rotating the second knob 61 , while the stoke of the outer tube 321 is restricted in the distal direction, thereby ensuring the relative translation between the inner member 72 and the outer annular member 71 , allowing the release of the stent 4.

[0079] The method according to the invention may further comprise exerting a holding pressure on the stent 4 with an elastic element 325 which is connected to the inner shaft 322 and to the outer tube 321 in order to bias the relative translation between the inner member 72 and the outer annular member 71 , wherein a proximal end of the stent 4 is positioned between the inner member 72 and the outer annular member 71 , and the apparatus 1 is configured so that the elastic element 325 is prestressed in order to press a proximal end of the stent 4.

[0080] The method according to the invention may further comprise setting the safety mechanism 9 in the first operating mode, prior to said releasing.

[0081] The method according to the invention may further comprise the step of longitudinally compressing the stent 4 by moving the inner elongated arrangement 32 of said catheter assembly in the distal direction, in particular through rotating of the second knob 61 .

[0082] The method according to the invention may further comprise the step of moving the outer sheath 31 in the distal direction in order to re-sheath the stent 4.

[0083] The method according to the invention may further comprise the step of moving the inner elongated arrangement 32 of said catheter assembly 3 in the proximal direction, in particular through rotating of the second knob 61 , in order to re-sheath the stent 4.

[0084] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in different mutually dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

Claims1 . A stent delivery apparatus (1 ) comprising:- a proximal handle (2),- a catheter assembly (3) comprising:- an outer sheath (31 );- an inner elongated arrangement (32) connected to said handle (2), said arrangement comprising an inner shaft (322), in particular a hollow inner shaft (322), and an outer tube (321 ) mounted coaxially in translation;- wherein at least one of the inner shaft (322) and outer tube (321 ) is able to be actuated in translation by a second sliding mechanism (6) having a second control member (61 ), in particular a second knob (61 ) mounted in rotation on said handle (2);- wherein the inner elongated arrangement (32) further comprises a distal clamp (7) adapted to hold or release a stent (4), said clamp (7) being formed by an inner member (72) and an outer annular member (71 ) mounted coaxially in translation, wherein in a hold position a proximal part of the stent (4) is held between an outer surface of the inner member (72) and an inner surface of the outer annular member (71 ) and wherein a relative translation between the inner member (72) and the outer annular member (71 ) allows the release of the proximal part of the stent (4);- wherein the stent delivery apparatus (1 ) is configured such that an actuation of the second control member (61 ) induces:- in a first functioning mode, a translation in unison of the inner shaft (322) and the outer tube (321 ) so as to push distally or pull proximally the proximal part of the stent (4) relative to the outer sheath (31 ), and- in a second functioning mode different from the first functioning mode, the relative translation between the inner member (72) and the outer annular member (71 ) allowing the release of the stent (4).

2. The apparatus (1 ) according to Claim 1 , wherein the proximal handle further comprises a safety mechanism (9) configured, in a first operating mode, to prevent the release of the stent (4), and, in a second operating mode, to allow the release of the stent (4), said safety mechanism (9) being configured to prevent the relative translation between the inner member (72) and the outer annular member (71 ) in the first operating mode, preferably when the second control member (61 ) induces the translation of the outer tube (321 ) and the inner shaft (322), and wherein an elastic element (325) is connected to the inner shaft (322) and to the outer tube (321 ) in order to bias the relative translation between the inner member (72) and the outer annular member (71 ), thereby exerting aholding pressure on the stent (4), the apparatus (1 ) being configured so that the elastic element (325) is prestressed in order to press a proximal end of the stent (4), said end being positioned between the inner member (72) and the outer annular member (71 ).

3. The apparatus (1 ) according to Claim 1 or 2, wherein the outer sheath (31 ) is connected to the proximal handle (2) and is able to be actuated in translation by a first sliding mechanism (5) having a first control member (51 ), in particular a first knob (51 ) mounted in rotation on said handle (2).

4. The apparatus (1 ) according to any of the preceding claims, wherein a distal end region of the outer tube (321 ) is attached to or comprises the outer annular member (71 ) and a distal end region of the inner shaft (322) is attached to or comprises the inner member (72).

5. The apparatus (1 ) according to any of the preceding claims, wherein the proximal handle (2) comprises a safety mechanism (9) configured, in a first operating mode, to prevent the release of the stent (4), and, in a second operating mode, to allow the release of the stent (4), said safety mechanism (9) being configured to prevent the relative translation between the inner member (72) and the outer annular member (71 ) in the first operating mode, preferably when the second control member (61 ) induces the translation of the outer tube (321 ) and the inner shaft (322).

6. The apparatus (1 ) according to any of the preceding claims, wherein an elastic element (325) is connected to the inner shaft (322) and to the outer tube (321 ) in order to bias the relative translation between the inner member (72) and the outer annular member(71 ), thereby exerting a holding pressure on the stent (4), preferably the stent delivery apparatus (1 ) being configured so that the elastic element (325) is prestressed in order to press a proximal end of the stent (4), said end being positioned between the inner member(72) and the outer annular member (71 ).

7. The apparatus (1 ) according to any of the preceding claims in combination with Claim 2 or 6, wherein the elastic element (325) is selected from a group of spring, elastomeric material, bellow structure, corrugated plate, compressible foam, tensioned elastic cord, and shape memory alloy, preferably a spring.

8. The apparatus (1 ) according to any of the preceding claims in combination with Claim 3, wherein the first sliding mechanism (5) comprises a first slider (52) and the second sliding mechanism (6) comprises a second slider (62), each slider (52, 62) being positioned in the proximal handle (2).

9. The apparatus (1 ) according to Claim 8, wherein the first slider (52) comprises an outer contour with splines adapted to cooperate with corresponding splines formed on an inner surface of the first control member (51 ), in particular the first knob (51 ), for transforming a rotation of the first control member (51 ), in particular the first knob (51 ), into a translation of the first slider (52) and the outer sheath (31 ), and wherein the second slider (62) comprises an outer contour with splines adapted to cooperate with corresponding splines formed on an inner surface of the second control member (61 ), in particular the second knob (61 ), for transforming a rotation of the second control member(61 ), in particular the second knob (61 ), into a translation of the second slider (62) and at least one of the inner shaft (322) and outer tube (321 ).

10. The apparatus (1 ) according to Claim 8 or 9, wherein the stent delivery apparatus (1 ) is configured so that the first slider (52) and the second slider (62) cannot overlap during their displacement.11 . The apparatus (1 ) according to any of Claims 8 to 10, comprising a first (55) and a second (56) abutment adapted to limit the stroke of the outer tube (321 ) in the distal direction, preferably via a sleeve (327), and the stroke of the second slider (62) in the distal direction, respectively.

12. The apparatus (1 ) according to any of Claims 8 to 11 in combination with Claim 2 or 6, wherein the inner shaft (322) is attached or rigidly connected to the second slider(62) and is able to be directly actuated in translation by said slider (62), and the outer tube (321 ) is able to be indirectly actuated in translation by said slider (62) via the elastic element (325).

13. The apparatus according to any of Claims 8 to 12 in combination with Claim 2 or 6, wherein the safety mechanism (9) is configured to:- when a coupling control element (91 ) of said mechanism (9) is set in the first operating mode, allow the translation in unison of the inner shaft (322) and the outer tube (321 ) as long as the second slider (62) is not restricted by the second abutment (56) in the distal direction, and- when the coupling control element (91 ) is set the second operating mode, allow both:- the translation in unison of the inner shaft (322) and the outer tube (321 ) as long as the outer tube (321 ) is not restricted by the first abutment (55) in the distal direction, preferably via the sleeve (327), and- the release of the stent (4) while the stroke of the outer tube (321 ) is restricted in the distal direction, preferably via the sleeve (327), by the first abutment (55), and the inner shaft (322) is displaced in the distal direction by the second slider (62).

14. The apparatus (1 ) according to the preceding claim, wherein the coupling control element (91 ) comprises or consists of a straightening strip (91 ) adapted to be engaged in a deformable protrusion (92) extending from the second slider (62) in distal direction.

15. The apparatus (1 ) according to any of the preceding claims in combination with Claim 8, wherein the first slider (52) is attached or rigidly connected to a proximal end region of the outer sheath (31 ).

16. The apparatus (1 ) according to any of the preceding claims in combination with Claim 8, wherein the inner shaft (322) is hollow and comprises or consists of a tube (322) extending from the second slider (62) to the outer annular member (71 ).

17. The apparatus (1 ) according to any of the preceding claims, wherein the inner shaft (322) comprises a clamp abutment (73), in particular said clamp abutment (73) comprising or consisting of a collar or flange.

18. The apparatus according (1 ) to any of the preceding claims in combination with Claim 16, wherein said catheter assembly (3) further comprises a central shaft (33), in particular a central tube (33), and a distal tip (34) connected to said central shaft (33), said distal tip (34) defining, with a distal portion of the outer sheath (31 ), a compartment (35) for housing the stent (4) before the release of the stent (4), wherein said central shaft (33) is positioned in the hollow inner shaft (322), in particular in the tube (322) of the hollow inner shaft (322).

19. A method for delivering a stent (4) in a patient and comprising:- providing a stent delivery apparatus (1 ) comprising a proximal handle (2) and a catheter assembly (3), said catheter assembly (3) comprising:- an outer sheath (31 );- an inner elongated arrangement (32) connected to said handle (2), said arrangement comprising an inner shaft (322), in particular a hollow inner shaft (322), and an outer tube (321 ) mounted coaxially in translation; wherein at least one of the inner shaft (322) and outer tube (321 ) is able to be actuated in translation by a second sliding mechanism (6) having a second control member (61 ), in particular a second knob (61 ) mounted in rotation on said handle (2); wherein the inner elongated arrangement (32) further comprises a distal clamp (7) adapted to hold or release the stent (4), said clamp (7) being formed by an inner member (72) and an outer annular member (71 ) mounted coaxially in translation, wherein in a hold position a proximal part of the stent (4) is held between an outer surface of the inner member (72) and an inner surface of the outer annular member (71 ) and wherein a relative translation between the inner member (72) and the outer annular member (71 ) allows the release of the proximal part of the stent (4);- a central shaft (33), in particular a central tube (33); wherein the stent delivery apparatus (1 ) is configured such that an actuation of the second control member (61 ) induces: in a first functioning mode, a translation in unison of the inner shaft (322) and the outer tube (321 ) so as to push distally or pull proximally the proximal part of the stent (4) relative to the outer sheath (31 ), and, in a second functioning mode different from the first functioning mode, the relative translation between the inner member (72) and the outer annular member (71 ) allowing the release of the stent (4); wherein a distal tip (34) connected to said central shaft (33) defines, with a distal portion of the outer sheath (31 ), a compartment (35) for housing the stent (4) before the release of the stent (4), wherein said central shaft (33) is positioned in the inner shaft (322), in particular in the hollow inner shaft (322);- loading the sent (4) into a compartment, in particular the compartment (35), and covering the compartment and the stent (4) with the distal portion of the outer sheath (31 );- inserting the catheter assembly (3) into the patient so that the stent (4) is positioned at a target location within the patient;- at least partially deploying a distal end of the stent (4) by moving the outer sheath (31 ) in the proximal direction;- releasing a proximal end of the stent (4) to ensure the full deployment of the sent (4), by moving the inner shaft (322) in the distal direction, while the stoke of the outer tube (321) is restricted in the distal direction, thereby ensuring the relative translation between the inner member (72) and the outer annular member (71 ) allowing the release of the stent (4).

20. The method according to Claim 19, wherein the proximal handle (2) comprises a safety mechanism (9) configured, in a first operating mode, to prevent the release of the stent (4), and, in a second operating mode, to allow the release of the stent (4), said mechanism being configured to prevent the relative translation between the inner member (72) and the outer annular member (71 ) in the first operating mode, preferably when the second control member (61 ) induces the translation of the outer tube (321 ) and the inner shaft (322).

21. The method according to Claim 19 or 20, wherein the outer sheath (31 ) is connected to the proximal handle (2) and is able to be actuated in translation by a first sliding mechanism (5) having a first control member (51 ), in particular a first knob (51 ) mounted in rotation on said handle (2).

22. The method according to any of Claims 19 to 21 further comprising exerting a holding pressure on the stent (4) with an elastic element (325) which is connected to the inner shaft (322) and to the outer tube (321 ) in order to bias the relative translationbetween the inner member (72) and the outer annular member (71 ), wherein a proximal end of the stent (4) is positioned between the inner member (72) and the outer annular member (71 ), and the apparatus (1 ) is configured so that the elastic element (325) is prestressed in order to press a proximal end of the stent (4).

23. The method according to any of Claims 19 to 22 further comprising setting the safety mechanism (9) in the first operating mode, prior to said releasing.

24. The method according to any of Claims 19 to 23 further comprising the step of longitudinally compressing the stent (4) by moving the inner elongated arrangement (32) of said catheter assembly in the distal direction, in particular through rotating of the second knob (61 ).

25. The method according to any of Claims 19 to 24 further comprising the step of moving the outer sheath (31 ) in the distal direction in order to re-sheath the stent (4).

26. The method according to any of Claims 19 to 25 further comprising the step of moving the inner elongated arrangement (32) of said catheter assembly (3) in the proximal direction, in particular through rotating of the second knob (61 ), in order to re-sheath the stent (4).

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