ITTO20090564A1 - DEVICE FOR THE TREATMENT OF VALVULAR MALFORMATIONS IN PERIPHERAL VENOUS VASES, WHICH, FOR EXAMPLE, THE INTERNAL JUNCTIONAL VEINS, IS RELATIVE TO THE KIT - Google Patents

Description

"Device for the treatment of valve malformations in peripheral venous vessels, such as internal jugular veins, and related equipment"

TEXT OF THE DESCRIPTION

Field of the invention

The present description refers to devices for the treatment of peripheral vessels.

This description has been developed with particular attention to its possible use for the treatment of jugular veins.

Description of the prior art

Documents such as PCT / IB2008 / 000621 and PCT / IB2008 / 000623 and again T02008A000654 have highlighted the existence of a possible correlation between chronic cerebrospinal venous insufficiency (Chronic Cerebro-Spinal Venous Insufficiency or CCSVI), in particular at the level of internal jugular veins (Internai Jugular Vein or IJV) and the onset of multiple sclerosis (MS).

These previous documents describe various techniques for detecting the risk of onset and / or treating this clinical picture.

Aims and summary of the present invention

The present invention aims to provide further improvements with respect to such techniques.

According to the present invention, this object is achieved thanks to a device having the characteristics recalled in the following claims. The invention also relates to a respective kit or kit comprising, in conjunction with the device described here, also instruction means (and for example printed instructions) for the use of this device for a valvotomy in a venous context such as for example the proximal segment of the vein. internal jugular.

The claims form an integral part of the technical teaching administered herein in relation to the invention.

The solution described here is inspired by the fact, observed by the Inventor through ultrasound, venographic, histological and post mortem investigations, that a significant percentage of patients with chronic cerebrospinal venous insufficiency associated with multiple sclerosis present in the proximal segment of the internal jugular vein (or IJV) a grossly malformed valve corresponding to the morphologies represented in Figures 1 and 2.

Both figure 1 and figure 2 are schematic representations of the proximal tract of the internal jugular vein IJV in which the presence of a malformed valve V can be found, capable of appearing as a "normal" valve whose valvular veils or leaflets L are oriented in the opposite direction to the direction of blood circulation (represented by the arrow BF and therefore oriented from top to bottom so as to indicate a direction of blood flow from the brain to the chest - remember that we are talking about a venous vessel ), as much as a valve whose non-functioning C cusps actually act as a septum. In both cases, an incorrect closure of the valve occurs at the moment of inspiration, with a net effect of regurgitation of the blood towards the brain. This effect is at the basis of the manifestation of the chronic cerebrospinal venous insufficiency.

Other morphological variants of this valvular malformation are observable, among which the most frequent are those of transversely oriented valve cusps, or fixed valve cusps which do not have the possibility to open or close respectively to favor blood flow or to prevent reflux. Whatever the morphology, the malformation of the valve prevents the correct passage of blood from the brain to the right atrium, resulting in a picture of CCSVI.

A treatment of percutaneous transluminal angioplasty (Percutaneous Transluminal Angioplasty or PTA) usually proves ineffective in healing a situation of this nature in a lasting way: the experimental data indicate that a treatment of PTA gives rise to recurrence of the pathological picture in a period of very short time

In one embodiment, the solution described here treats the problem outlined above through endovascular valvotomy (therefore of the non-invasive or minimally invasive type) of the malformed valve.

Up to now, endovascular valvotomy has been limited to interventions in arterial contexts (for example to perform the ablation of the valve veils of an aortic valve in view of its replacement with a valve prosthesis implanted via the skin) or to interventions in venous contexts, for example, in the technique known as saphenous vein valvotomy to perform arterial bypasses for the lower limbs in critical ischemia, using the devalvolated saphenous vein as an in situ arterial prosthesis.

The saphenous vein is a vessel that on average has a diameter of half a centimeter and a length that goes from the medial malleolus to the groin. De-valvulation is in fact necessary to arterialize the saphenous vein, which after surgery no longer belongs to the venous system but to the peripheral arterial one. Devalvulation generally occurs blind, ie without any radiological control or guidance, with valvulotomal catheters inserted during an open and non-endovascular surgery. The valvulotome catheters can be resterilizable or disposable, with a variable diameter between 3mm and 7mm and of the length mentioned above. The radiological control takes place at the end of the operation (open and not endovascular) to verify the patency of the arterial bypass with devalved saphenous left in situ.

In one embodiment, the solution described here addresses the specific problems related to the realization of a valvotomy in a venous context such as for example the proximal segment of the internal jugular vein. In this context it is therefore a question of devalvulating a vein affected by the presence of a malformed valve. The devai volation does not have the purpose of arterializing a vein, but rather the purpose of allowing a regular passage of the cerebral blood back into the internal jugular vein. The operation can take place endovascularly and not in the open, under radiological control or even high resolution ultrasound. The way of introduction can be the femoral vein, with the use of catheters of a variable length between 100 and 120 cm, capable of sliding on a guide.

In various embodiments, provision is made for the use of a catheter with an external control which allows the deployment of a valvulotome or instrument and of a basket or basket for collecting the residues of the devalvulation.

In various embodiments, the diameter of the deployed valve varies between 6 and 12mm. In various embodiments, the device is of the self-centering and self-sizing type.

Brief description of the annexed representations The invention will now be described, purely by way of non-limiting example, with reference to the annexed representations, in which:

- Figure 1 and Figure 2 have already been described above,

- figure 3 is a schematic representation of the methods of use of the device described here, and

Figures 4 and 5 are two longitudinal sectional views of part of the device illustrated here, shown in the condition of introduction and in condition of use.

Detailed description of embodiments The following description illustrates various specific details aimed at an in-depth understanding of the embodiments. The embodiments can be made without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments.

Reference to "an embodiment" within this description means that a particular configuration, structure or feature described in relation to the embodiment is included in at least one embodiment. Therefore, phrases such as "in one embodiment", possibly present in different places of this description, are not necessarily referred to the same embodiment. Furthermore, particular conformations, structures or features can be combined in a suitable way in one or more embodiments.

The references used here are for convenience only and therefore do not define the scope of protection or the scope of the forms of implementation.

In Figures 3 to 5, reference 10 generally indicates a device for carrying out a valvotomy of a malformed valve V present, for example, in the proximal segment of the internal jugular vein IJV. Valvulotomy surgery involves at least partial ablation of the related valve veils and / or of any non-functioning cusps acting as a septum hindering the flow inside the lumen of the IJV vein.

In one embodiment, the device 10 is placed at the distal end of an introduction catheter C - only partially visible in Figure 3 - so that it can be positioned by catheterization in a jugular vein in correspondence with the distal jugular lumen "" (near the confluence of the brachiocephalic trunk). In one embodiment, the catheter C for positioning the device 10 is compatible with 6-8 French introducers; It is flexible, sliding with resistance to kinking even in curvilinear paths, it has a length of, for example, 100-120 cm.

In the illustrated embodiment, the device 10 essentially comprises two elements:

an ablation instrument 12, intended to carry out the cutting operation which is at the base of the valvotomy, e

a collection element 14 having an open structure, substantially similar to that of a canister, having the function of collecting the valve veils or, in any case, the residues released by the ablation action carried out by the instrument 12, avoiding that such residues, carried by the bloodstream BF, they can flow in an undesirable way towards the chest with the risk of producing a pulmonary embolism.

As can be better appreciated in the view of Figure 3, in the condition of use, the two elements 12 and 14 are intended to be arranged astride the zone V where the valvotomy is performed.

This straddle arrangement provides that the cutting instrument 12 and the "basket" 14 are respectively arranged in a distal position and in a proximal position with respect to the region V. The terms "distal" and "proximal" are used here with reference to the direction of introduction catheter C and therefore, generically, in the anatomical sense: it will in fact be appreciated that the flow of blood BV in a venous vessel occurs in a distal-proximal direction, ie from the periphery towards the center of the body.

The instrument 12, the characteristics of which will be better illustrated hereinafter, has on its proximal side - therefore in the position facing the region V in the condition of use of Figure 3 - one or more cutting edges 120.

Once the cutting instrument 12 and the collection element 14 are arranged astride the region V, by acting on the catheter C in the sense of recalling the device 10 in the proximal direction, i.e. in the direction of extraction of the catheter, it is possible to so that the cutting edge 120 acts on the valve V realizing the desired valvotomy action. The action in question can also involve a rotation of the catheter C around its axis.

The valvulotomy residues (valve veils, etc ...) thus released are dragged by the blood flow BF inside the basket element 14, whose open structure, for example a mesh, offers minimal resistance to blood flow but it holds within it what is carried away by the bloodstream itself.

Figures 4 and 5 show a possible embodiment of the device 10 aimed at taking into account the fact that:

the device 10 is placed on the valvotomy site by advancing it through the patient's vascular system (for example following insertion into the femoral vein, right or left), and

once the valvotomy has been performed, the device 10 is extracted from the patient's body, making him travel backwards along the path he traveled to reach the site of the valvotomy.

In the example of embodiment illustrated in Figures 4 and 5, the numerical reference 100 indicates a tubular core which can in fact correspond to a tubular core of flexible material (for example plastic material) constituting the core of the catheter C as a whole. .

A thread-like actuation element 102 is slidably mounted inside the core 100. The element 102 is capable of being maneuvered, making it slide longitudinally with respect to the core 100, acting on the proximal end of the catheter C by means of a actuation device 104 which will be better described in the following.

Similarly, a tubular sheath 106 is slidably fitted onto the tubular core 100 and is also capable of being made to slide longitudinally with respect to the core 100 by acting on the actuation device 104, located at the proximal end of the catheter C.

It will be appreciated that the technique of producing the operation of elements located at the distal end of a catheter by means of actuation devices situated at the proximal end of the catheter itself, with such devices capable of causing longitudinal sliding with respect to the catheter of thread-like actuation elements and / or tubular, it is a widely used technique in many sectors of non-invasive surgery (for example for the implantation of coronary stents or similar devices), which makes it unnecessary to provide a more detailed description here.

In the illustrated example, the drive wire 102 is connected at its distal end to a hollow capsule 110 having a spindle or ogive shape. The capsule 110 therefore forms a sort of cap having a shape that is approximately similar to the shape of the cap of a mushroom and is therefore able to conceal with its proximal edge a real cutting tool or valvulotome that carries the cutting edge or edges 120. In the illustrated example, the valvulotome comprises a hub 120a fixed to the end of the core 100 and a plurality of spokes or spokes 120b extending from the hub 120a and carrying at their ends a cylindrical skirt 120c whose proximal edge precisely constitutes the edge cutting edge 120.

In the condition (of introduction) shown in Figure 4, the valvulotome with the cutting edge 120 is inserted (ie "inserted") into the proximal edge of the capsule 110. In this condition, the capsule 110 therefore covers the valvulotome and maintains the cutting edge 120 in a hidden condition with respect to the outside: this prevents the edge 120 from damaging the tissues with which the device 10 comes into contact while the device itself is made to advance towards the site of the valvotomy.

The sheath 106 has at its distal end a slightly enlarged part 106a with the function of retaining the basket element 14 in a radially contracted condition while the device 10 is made to advance towards the site of the valvotomy in the condition shown in Figure 4.

The various details of the solution illustrated here are however to be considered of an exemplary nature and certainly not mandatory.

For example, the sheath 106 could have a non-enlarged distal end (i.e. be a sheath of constant diameter along its entire length, with the canister member 14 housed in a corresponding annular groove formed in the core member 100). Similarly, the capsule 110 could have a different shape, for example a prismatic shape and have a distal end with a shape different from the rounded shape illustrated here, intended to facilitate the advancement of the device 10 towards the valvotomy site.

The embodiment considered here allows the operator to introduce the device 10 into the patient's body and to make it advance towards the site of the valvotomy in conditions of minimum resistance to advancement, i.e. with the capsule 110 which exerts its ogive effect while maintaining in the concealed condition the valve valve and the sheath 106 which holds the canister element 14 in the radially contracted condition referred to in Figure 4.

Once the positioning on the V site of the valvotomy has been achieved (a condition that can be detected for example thanks to the presence of one or more "marker" 112 radiopaque present on the device 10, for example in an intermediate position between the instrument 12 and the canister element 14), by acting on the device 104 the operator can produce the deployment of both the instrument 12 and the canister element 14, bringing them to the operating condition referred to in figure 5.

In the embodiment illustrated here, the deployment of the element 12 is achieved by the fact that the valvulotome is at least partially "extracted" from the capsule 110 in such a way that the cutting edge 120 protrudes outside the edge of the capsule so as to be able to carry out the desired cutting action according to the criteria schematically illustrated in figure 3.

This result can be obtained as a result of a relative movement of the core 100 and of the thread 102 such as to ensure that (as well as directly appreciable from the comparison of figures 4 and 5), the core 100, on which it is fixed the valvulotome, moves back with respect to the thread 102, which carries the capsule 110, thus causing the edge 120 to protrude with respect to the capsule 110. The fact of speaking of a relative movement takes into account the fact that the same result can also be obtained by advancing the thread 102, which carries the capsule 110, with respect to the core 100, on which the vaivulotome is fixed, or by moving both the core 100 and the thread 102.

Again, it has been assumed here that the deployment of the valvulotome involves only a (relative) sliding with respect to the capsule 110. In various embodiments (in addition or as an alternative to this relative sliding movement) it can be foreseen that, in the condition of introduction of Figure 4, the capsule 110 maintains the valvulotome in a radially contracted condition, facilitating the advancement towards the valvulotomy site, and that the capsule, by disengaging the valvulotome, allows the valve itself to expand radially.

In the embodiment example considered here, such a deployment mechanism is adopted for the canister element 14. For example, in one embodiment, the canister element 14 can be made of a superelastic material and / or with shape memory characteristics such as the material known as Nitinol. Once released from the containment action carried out by the sheath 106a, retracted by acting on the sheath 106, the basket element 14 reaches the desired unfolded condition.

The basket element 14 is particularly suitable for being made with materials such as Nitinol and with a reticular structure which, without prejudice to the general diverging and preferably slightly bowl shape in the unfolded condition, has been used for some time both for stent for angioplasty, both to create prosthetic heart valve structures intended to be implanted percutaneously or with "sutureless" techniques.

In the example of embodiment illustrated here, the basket element 14 has a proximal shank 140 which, when the sheath 106 itself is retracted, remains in any case inserted in the sheath 106 itself while the distal part of the element 14 opens like a basket towards the tool 12.

Both in the case of element 12 and in the case of element 14, instead of an unfolding mechanism based on elasticity / shape memory characteristics, it is possible to use a positive type unfolding mechanism, controlled for example by means of a balloon mounted at the distal end of the catheter.

In the embodiment considered here, the transition from the condition of introduction (represented in figure 4) to the unfolded condition of use (represented in figure 5) is at least partially reversible both as regards the instrument 12 and as regards the element to basket 14.

Once the valvulotomy has been completed, the device 10 can thus be at least partially brought back to the condition of Figure 4, i.e. with the cutting edge 120 hidden again inside the capsule 110, so as to be able to recall the device 10 towards the outside the patient avoiding unwanted cutting phenomena along the backward path.

This feature is otherwise advantageous since, should the valvulotomy procedure be aborted for some reason, it allows the device 10 to be easily recalled towards the outside of the patient.

Once the valve veils and / or any other residue from the valvotomy operation has been received inside, the canister element 14 can no longer be recalled in the radially contracted condition of Figure 4. In any case, the extraction movement backwards of the basket element 14, even in a radially expanded condition, is not in general at the basis of undesirable phenomena affecting the vessels involved in the catheterization. This is especially true if the basket element 14 is made of (super) elastic material, capable of yielding easily without giving rise to damage to the walls of the vessels crossed backwards during the extraction of the device 10. In this regard, a beneficial role is also played by the general divergence of the basket element 14, facing distally: during the return movement the basket element 14 therefore has an "aerodynamic" shape such as to facilitate sliding along the wall of the vessels during the reverse extraction movement.

At the same time it will be appreciated that the proximal edge of the capsule 110, intended to conceal the valvulotome (see Figure 4), has a rounded external shape, also "aerodynamic" and such as to facilitate sliding along the wall of the vessels both during the forward movement of the device 10 towards the site of the valvotomy, both during the backward extraction movement.

The control device 104 can be made (according to criteria known per se) in such a way as to act on the core 100, on the wire 102 and / or on the sheath 106 so as to command the deployment of the cutting tool 12 and of the collection element 14. This both in sequence, i.e. in successive moments, and simultaneously, i.e. together: the latter solution can be advantageous as it ensures that the cutting edge 120 is in a position to perform the cutting action only when the collection element 14 is also deployed and able to collect the relative residues avoiding their dragging by the blood flow BF.

For example, the device 104 may have a general pistol-like configuration and comprise a lever 1042 similar to the brake lever of a bicycle operable to simultaneously control the deployment of the cutting tool 12 and the collecting element 14. This trigger shape or a brake lever allows to control in a regulated and precise way the exit of the cutting formation 120 from the capsule 110.

Again with known means (for example by mounting the sheath 106 and the element 14 on an intermediate tubular sheath - not expressly illustrated in the drawings - slidable longitudinally on the core 100 under the control of an adjustment wheel 1044 or an equivalent member) It is possible to make selectively adjustable - before and / or after deployment - the distance between the cutting tool 12 and the collecting element 14 (see for example the distance D in figure 5) so as to adapt it optimally to the needs of intervention.

In other embodiments, the ring nut or wheel 1004 can be split and comprise, in addition to a part intended to adjust the distance between the elements 12 and 14, a part intended to allow choosing the simultaneous deployment of the cutting tool 12 and the basket element 14, at the same time.

In this way the catheter, both inlet and outlet, will have a small footprint, minimizing its invasiveness.

Naturally, the principle of the invention remaining the same, the details of construction and the embodiments may vary, even significantly, with respect to what is illustrated here purely by way of non-limiting example, without thereby departing from the scope of the invention. , as defined by the appended claims.

Claims (13)

CLAIMS 1. Device for venous valvotomy that can be introduced via an introducer catheter (C), the device comprising: - a cutting instrument (12) carrying at least one cutting formation (120) to perform the valvulotomy action, and a collection element (14) of the valvotomy residues disposed in a proximal position with respect to said cutting instrument (12) to collect said valvotomy residues dragged by the blood flow starting from said cutting instrument (12). Device according to claim 1, wherein said collection element (14) has an open structure so as to allow free flow of blood through the collection element (14). Device according to any one of the preceding claims, wherein at least one (14) between said cutting tool (12) and said collecting element (14) is expandable between a radially contracted condition of introduction of the patient's body and a condition radially expanded to perform valvotomy. 4. Device according to claim 3, wherein said at least one (14) between said cutting tool (12) and said collecting element (14) is made of elastic material so that expansion towards said radially expanded condition is achieved for elastic effect. 5. Device according to any one of the preceding claims 3 or 4, wherein said at least one (14) between said cutting tool (12) and said collecting element (14) has associated a radial confinement element (106a) to confine it in said radially contracted condition, said radial confinement element (106a) being disengageable from said at least one (14) between said cutting tool (12) and said collecting element (14) in view of allowing its expansion towards said radially condition expanded. Device according to any one of the preceding claims, wherein said cutting tool (12) has associated a covering element (110) capable of keeping said at least one cutting formation (120) hidden from the outside during introduction of the patient's body and selectively uncovering said at least one cutting formation (120) to perform said valvotomy action. Device according to claim 6, wherein said at least one cutting formation (120) and said covering element (110) are operable with a relative longitudinal sliding movement with respect to said introduction catheter (C). 8. Device according to claim 6 or claim 7, wherein said cover element (110) has a general hood shape with said cutting formation (120) selectively insertable and disconnectable with respect to said hood. Device according to any one of the preceding claims 6 to 8, in which said covering element (110) has an ogive profile to facilitate the advancement towards the site of the valvotomy. Device according to any one of the preceding claims 6 to 9, wherein said at least one cutting formation (120) has a general ring configuration. Device according to any one of the preceding claims, in which said collection element (14) has a general shape of a basket opening distally with respect to the device (10) itself. Device according to any one of the preceding claims, comprising a control device (104) in a proximal position with respect to said introduction catheter (C) and comprising at least one of: a control member (1042) for sequentially or simultaneously controlling the deployment of said cutting tool (12) and said collecting element (14) between a condition for introducing the patient's body and a condition deployed for unwinding valvulotomy, e - an adjustment member (1044) for adjusting the distance (D) between said cutting tool (12) and said collecting element (14). 13. Kit or kit including: - a device (10) according to any one of claims 1 to 12, and - means for instructing the use of the device itself for a valvotomy in a venous context, preferably the proximal segment of the internal jugular vein.