WO2010101464A1

WO2010101464A1 - Endovascular treatment device, system for endovascular treatment and method of operating (the same)

Info

Publication number: WO2010101464A1
Application number: PCT/NL2010/050114
Authority: WO
Inventors: Antonius Johannes Cornelis Stokbroekx; Marc Emmanuel Henri Jozef Vuylsteke
Original assignee: TOBRIX BV
Current assignee: TOBRIX BV
Priority date: 2009-03-06
Filing date: 2010-03-08
Publication date: 2010-09-10
Anticipated expiration: 2011-09-06
Also published as: EP2403423A1; NL2002597C2

Abstract

The present invention relates to an endovascular laser treatment device, comprising an optical fibre having a tip configured to emit laser light locally to treat the inner vessel wall and a spacer element arranged close to the distal fibre tip and operable to position the distal fibre tip away from the vessel wall, the spacer element being shaped so as to prevent the fibre tip to be moved further into the blood vessel. The invention also relates to a system comprising a such device and a catheter, the catheter and fibre comprising a first connector and second connector respectively for releasably attaching the catheter to the fibre, wherein the second connector is fixed to the fibre at a position such that the fibre tip and the at least one spacer element extend from the distal end of the catheter when the first connector is attached to the second connector.

Description

ENDOVASCULAR TREATMENT DEVICE, SYSTEM FOR ENDOVASCULAR TREATMENT AND METHOD OF OPERATING (THE SAME)

The present invention relates to an endovascular treatment device, a system for endovascular treatment and to a method of operating a system comprising an endovascular treatment device.

For the treatment of a blood vessel in general or veins in particular endovascular laser therapies have been developed. In this type of therapy laser energy is delivered by a flexible optical fibre to specific pathological locations in the vessel. A guiding catheter is percutaneously inserted into a vein and guided to the location to be treated. Once the distal end of the guiding catheter has reached the area close to the location to be treated, a laser fibre is inserted into a passage formed in the guiding catheter until the distal tip of the laser fibre reaches the location to be treated. The laser fibre is advanced so that the laser fibre tip exits the distal end of the guiding catheter and is exposed inside the blood vessel. The laser fibre is connected to a suitable laser source. Once the laser fibre tip has been exposed, the laser source is energized and the laser energy travels through the laser fibre towards the distal laser fibre end or laser fibre tip. The distal laser fibre tip emits the light energy into the blood vessel. The light energy is absorbed by the blood and the vein wall. When light energy is absorbed by tissue, it is transformed into thermal energy. The thermal energy may cause suitable cell necrosis and sometimes even collapse of the vessel wall.

More specifically, in case of treatment of variocose veins an endo venous laser treatment has been introduced as a minimal invasive alternative to the classical stripping. A difference with the classical treatment is that the crossectomie is no longer performed and the saphenous vein is obliterated in a percutaneous way. This treatment has shown a lower morbidity, a shorter sick leave and less postoperative pain compared to the classical stripping treatment. Nevertheless some inconveniences as postoperative ecchymosis, bruising and periphlebitis jeopardize the reconvalence. Some of these side- effects can be due to the direct contact between the fibre tip and the vein wall. Direct contact with the vessel wall may be due the fact that the laser fibre used in endo venous laser treatment tends to be rather rigid. When this fibre is introduced in a saphenous vein, which usually has some small tortuosities and turnings, the fiber has a tendency to stretch. As a consequence of this stretching, the fibre tip is situated eccentric in the vein and frequently even hits the vessel wall. When in such a situation the energy is delivered from the fiber tip, a direct contact between the fiber tip and the vessel wall may result in a destruction and ulceration or perforation of the vein.

More specifically, when the fibre tip contacts the wall of the blood vessel during the treatment with laser light, the laser energy is delivered directly to the vessel wall rather than indirectly. This laser energy tends to perforate the blood vessel wall. The perforation of a blood vessel, for instance a vein or other type of vessel, may result in extravasation of blood in the perivascular tissue. When the fibre tip touches the vein wall during the treatment, it will result in local ulcerations and perforations of the vein wall. The tissue effects, like ulceration and perforation, are achieved not only by direct absorption of laser light, but by convection of heat energy from the fibre tip into the surrounding tissue. At these points of direct contact the temperature can rise to 300⁰C. Due to the heat dissipation, vein wall cells at a distance from this point of direct laser impact become necrotic. The steam produced by absorption of laser energy by the blood is a tiny fraction of the energy necessary to damage the vein wall and cannot be the primary mechanism of injury to the vein with endovenous laser. The bubbles grow and when they extend into a cooler area they collapse. By emptying the vein, the light energy will be absorbed by vein wall cells directly and converted to thermal energy. The cytoplasma will be heated causing denaturation of intracellular proteins. So not only direct contact but also light energy absorption by intracellular cytosol of vein wall cells takes part in the mechanism of action of ELT. This laser energy tends to perforate the blood vessel wall and creates a passage for blood to enter the perivascular tissue.

In an attempt to avoid the perforation of the vein wall during a laser treatment it has been proposed in WO 2004/004546 to arrange a spacer close to the distal end of the optical fibre. More specifically, the spacer is arranged at a specific distance, for example several centimeters, from the distal end of the optical fibre, i.e. from the (bare) tip of the fibre. The known design involves an outer sleeve coaxially arranged around an optical fibre and permanently attached to the fiber at the distal end of the sleeve at a bonding point. The outer sleeve can be moved longitudinally relative to the optical fibre except at the bonding point. The sleeve incluses a plurality of slits to define a plurality of ribs each arranged between two adjacent slits When the sleeve is moved longitudinally toward the fibre tip, the ribs between the slits bend causing the ribs to expand radially outward. In the expanded position the ribs may function as a spacer for the optical fibre. By locating the spacer at a couple of centimeters proximal to the distal end of the optical fibre a direct contact between the fibre tip and the inner wall vein can be avoided during treatment, which reduces the risk of perforation of the vessel wall. However, the known system has a number of drawbacks which will become apparent from the following sections.

For instance, when performing a laser ablation of the great saphenous vein, care should be taken to prevent the laser from emitting energy in the deep vein system. An accidental heating of the blood in or near the deep system could result in a deep venousthrombosis. The fibre tip should therefore be carefully placed a specific distance, for instance 2-3 cm, distally to the sapheno-femoral junction. The known spacer design makes it possible to advance the fibre tip into the vessel or to retract the fibre tip from the vessel. However, advancement of the fibre tip, for instance in the direction of the sapheno-femoral junction, may be dangerous since optical energy delivered by the fibre tip could reach the deep vein system. Furthermore, the positioning of the fibre tip from which the laser energy is emitted, should be performed with great accuracy. To improve the accuracy of the placement of the fibre, it may be performed under ultrasound control. It has been proven to be difficult to positively identify the laser fibre tip on the video screen of an ultrasound imaging system. Furthermore, since the distal end of the fibre tip is spaced (by several centimeters) from the position of the spacer, the location of the spacer is not a reliable indication of the position of the end of the fibre, i.e. the fibre tip from which the optical energy is transmitted.

A further drawback of the known system is that is impossible to localize the fibre tip relative to the spacer end. The tip can be pushed up too far away from the catheter, thus eliminating the possibility to avoid direct contact with the vein wall, or it can be localized too close to the catheter resulting in melting and carbonizing the catheter.

US 2008/0292255 Al discloses an alternative design of a spacer element for an optical fibre. The design involves an outer tube or shaft, an inner tube and an optical fibre, the inner tube being arranged coaxially in the outer tube and the optical fibre being arranged coaxially in the inner tube. Attached to the inner tube is a plurality of expandable members. The expandable members surround and are radially spaced from the emitting tip of the optical fibre. The expandable members, which are attached to the distal end of the inner tube, are retractable into the shaft by drawing the inner tube proximally into the surrounding outer tube. The outer tube then forces the expandable members radially inward.

With the expandable members in the retracted position the sheath, i.e. the outer tube, the inner tube and the retracted epandable members, is delivered over a guidewire to the desired treatment location. Once the sheath is in position, the guidewire can be withdrawn and the outer and inner tubes of the sheath are moved relative to each other such that the expandable members move distally beyond the end of the outer tube. The members then self-expand. The optical fibre can then be advanced down the shaft and positioned so that the tip is disposed within the members and spaced proximally from the distal ends of the expandable members by a distance of 2 mm to 20 mm.

A drawback of this known design is that a correct relative position of the distal end of the optical fibre and the distal ends of the expandable members cannot be guaranteed (regardless of whether or not a marker on the optical fibre is present) because the inner tube and outer tube can move relative to each other. Furthermore, the distal ends of the expandable members extend distally from the distal end of the optical fibre over a distance of 2 mm - 20 mm.

It is an object of the present invention to provide an endo vascular treatment device, a system for endovascular treatment and/or a method of operating a system comprising an endovascular treatment device wherein at least one of the above- mentioned drawbacks and/or other drawbacks or problems of the prior art have been been obviated or at least reduced.

According to a first aspect of the invention an endovascular laser treatment device is provided, the device comprising: an optical fibre configured to be inserted into a blood vessel and having a distal fibre tip configured to emit laser light locally to treat the inner wall of the blood vessel; at least one spacer element fixed to the optical fibre, the spacer element being operable to position the distal fibre tip away from the vessel wall, the spacer element being shaped so as to prevent the fibre tip to be advanced further into the blood vessel.

The shape and arrangement of the spacer element helps to prevent the fibre moving further into the blood vessel, thus reducing the risk of entering the deep venous system provoking a deep venous thrombosis. The spacer element is also shaped and arranged to reduce the risk of perforations of the wall of the blood vessel, while navigating into the vessel.

In an embodiment at least one free end of the spacer element is positioned within 1 mm proximal or distal from the distal end of the fibre. Positioning the spacer element too far away from the end of the fiber in de the proximal direction limits the desired effects of the invention. More precisely, the hot fibre tip may be touching the vein wall when the vein is curved beyond the spacer and it is possible to perforate the vein when advancing the fiber further into the vein which may be dangerous. If, on the other hand, the spacer element is arranged too far beyond the distal end of the fibre, the risk of a large clod of coagulated or carbonized blood accumulating between the spacer elements in front of the distal end of the fiber will prevent the proper distribution of laser energy to the vein wall.

In an embodiment the spacer element is fixed to the distal fibre tip and is operable to push away the vessel wall. Although in some embodiments the fibre tip is not centralised inside the vessel, However, in other embodiments the spacer element is also operable to essentially centralise the fibre tip within the vessel. This reduces the risk of perforations even further.

In an embodiment of the invention the spacer element is shaped so as to both prevent the fibre tip to be moved in a direction further into the blood vessel and still allowing movement of the fibre in the opposite direction. More specifically, when the fibre is inserted in the blood vessel by the use of a guiding catheter and the fibre tip extends from the distal end of the catheter, the shape and arrangement of the spacer element at the end of the fibre prevent the fibre to be pushed further into the vessel and enable withdrawal of the fibre by retracting the fibre from the guiding catheter. According to another embodiment the spacer element comprises a plurality of spacer legs arranged in a generally longitudinal direction, each spacer leg having a fixed end attached to the fibre and a free end for contacting, preferably engaging on, the vessel wall. The free ends of the spacer legs come into contact with the vessel inner wall when the fibre tip comes close to the vessel wall. Due to the properties of the spacer legs (for instance the shape, location, mechanical properties (for instance, elasticity) and/or dimensions), the free ends of the spacer legs will engage on the vessel wall. Due to the friction between the free ends of the spacer legs (which may even cause the spacer legs to get stuck in the vessel when they are pushed further into the vessel), the fibre tip is prevented to advance essentially further into the blood vessel.

In a particular preferred embodiment the spacer element is generally tulip-shaped. The tulip shape provides the legs with sufficient strength so that the risk of damage to the legs, which may even lead to one or more legs to become detached from the remaining part of the spacer element, is reduced. The distal portions of the respective legs or leaves of the tulip shaped spacer element are pointed which results in a particular good contact with the vessel wall. Due to this contact between the pointed distal ends of the legs of the spacer element and the vessel wall the risk of the fibre to be advanced further into the vessel is reduced.

Preferably, the spacer element is designed in such a way that it prevents the fibre to advance further into the vessel, while at the same time a relatively large distance from the fibre tip to the vessel wall, even in case the fibre extends obliquely relative to the vessel wall. The spacer element may be shaped such that the location wherein the spacer element defines a maximum cross-section is located at or even distally beyond the distal end of the optical fibre tip. A tulip-shaped spacer element suitably positioned on the fibre is one of the embodiments that enables the creation of a maximum cross- section at the end of the fibre tip or beyond the fibre tip.

In a further embodiment the spacer element comprises a plurality of self expandable spacer legs, the spacer legs being operatively biased to a radially outward direction. When the spacer legs of the spacer element are not maintained in an unexpanded state, for instance by arranging a sleeve or similar element around the spacer element, the spacer legs may automatically expand in at least the radial direction. This implies that no further means are needed to cause the spacer element to enter the expanded state wherein it can keep the fibre tip spaced away from the inner wall of the blood vessel.

In a further embodiment the spacer element is made of shape-memory material, for instance nitinol or the like, and is moveable between a unexpanded position wherein it is arranged around the fibre and an expanded position wherein it is extending radially outward from the fibre tip. The spacer element has the tendency to take the expanded position and may be forced to take the unexpanded position, for instance by arranging over the spacer element a sleeve, for instance formed by a separate element such as a pusher element, and/or by a separate guiding catheter or similar element. In an embodiment a spacer leg has a proximal portion attached to the fibre and a distal, free portion. In further embodiments the length of the distal portion of the spacer leg may be about 1 mm - 10 mm or, preferably, between 4 mm - 6 mm. Depending on the diameter of the blood vessel to be treated the preferred length may vary slightly. For a typical blood vessel the length in either of the above-mentioned ranges is found to be particularly suitable for the purpose of allowing movement of the fibre tip in one direction only.

In further embodiments the at least one free end of the spacer element is positioned at or beyond the fibre tip. In an embodiment the fibre tip may be covered by the spacer element. In these embodiments the position of maximum cross-section is localised at the fibre tip or beyond. The spacer element makes it possible to realize a relatively large cross-section of the blood vessel right in the area in which the optical energy is emitted. This not only reduces the risk of inadvertently contacting the vessel wall, but also provides for a relatively even distribution of the optical energy in the vessel. Furthermore, the positioning of the spacer element at or beyond the fibre tip allows for a good localization of the fibre tip during an endovascular procedure. In an embodiment the spacer element is at least partly made of echogenic material, i.e. material showing a relatively high reflectivity for ultrasound waves. Examples of this type of material include - but are not limited to - metals, for instance nitinol, polymers with or without radiopac and similar materials.

In an embodiment the spacer element may be in an undeployed state in which the spacer element is essentially unexpanded, during the insertion of the fibre and the spacer element into the blood vessel (or during retraction from the same). The spacer element may also be brought to a deployed state in which the spacer element is expanded in a essentially radial direction after the spacer element has been inserted in the blood vessel.

In order to maintain the spacer element in the undeployed state, a sleeve or similar element may be arranged around the spacer element. The sleeve prevents the spacer element to automatically expand from the unexpanded position to the expanded position. The combination of the fibre, spacer element and sleeve has a diameter that still is small enough to allow the combination to be inserted into the blood vessel (directly in the vessel or indirectly by means of a guiding catheter or the like). In situations wherein the fibre and the spacer element are not present inside the guiding catheter, the sleeve may be formed by a pusher element that can be slid over the fibre and the spacer element. When the fibre and spacer element are inserted into the guiding catheter, the sleeve may be formed by the guiding catheter itself. As long as the spacer element remains inside the guiding catheter, the spacer element remains in its undeployed state.

In further embodiments the endovascular treatment device comprises a connector to attach the fibre to a guiding catheter, the connector being fixed to the fibre at a position such that the fibre tip and the at least one spacer element extend from the distal end of the guiding catheter when the fibre is attached to the guiding catheter. According to another aspect of the invention a system for endovascular treatment is provided, the system comprising:

- an endovascular laser treatment device as defined herein;

- a guiding catheter configured to be inserted into the vessel and having a passage for the fibre and the at least one spacer element; the guiding catheter and fibre comprising a first connector and second connector respectively for releasably attaching the guiding catheter to the optical fibre, wherein the second connector is fixed to the fibre at a position such that the fibre tip and the at least one spacer element extend from the distal end of the guiding catheter when the first connector is attached to the second connector. This ensures that the fibre cannot be activated inside the guiding catheter by wrong placement of the fiber initially or by moving the fiber into the guiding catheter during lasering and pullback. wherein the first and second connectors define an interior space that is shaped and dimensioned to accommodate the pusher element when the connectors attach the fibre to the guiding catheter. In a further embodiment of the system the first connector and the pusher element are configured to essentially maintain the at least once spacer element in the unexpanded position while inserting the fibre tip from the pusher element into the guiding catheter. For instance, when the fist connector is connected to the second connector and the pusher element is accommodated inside the interior space in the connectors, the proximal end of the guiding catheter or the entrance opening of the first connector is close to or abuts the distal end of the pusher element so that the fibre an spacer element may be pushed into the passage in the guiding catheter without the spacer element expanding from the unexpanded position to the expanded position. In another embodiment the first and second connectors define an interior space that is shaped and dimensioned to accommodate the pusher element when the connectors attach the fibre to the guiding catheter. When the first and second connector are disconnected and the fibre is retracted from the guiding catheter, the fibre tip with the spacer element is received again in the pusher element present in the interior space so that the spacer element remains in the unexpanded position and is ready for subsequent use.

According to another aspect of the invention a method of operating a system comprising an endo vascular treatment device is provided, the method comprising: - providing a guiding catheter configured to be inserted into a blood vessel and having a passage for insertion of an optical fibre having a distal fibre tip configured to emit laser light locally to treat the inner wall of the blood vessel and at least one spacer element arranged close to the distal fibre tip;

- arranging a deployment element around at least a part of the at least one spacer element to maintain the spacer element in an undeployed state;

- inserting the distal fibre tip into the passage in the guiding catheter while keeping the spacer element in the undeployed state;

- advancing the fibre through the guiding catheter so that the spacer element of the fibre extends beyond the distal end of the guiding catheter and expands to the deployed state.

Further advantages, characteristics and details of the present invention will become apparent from the following description of preferred embodiments thereof. In the description reference is made to the annexed drawings, that show:

- figure 1 a schematic view of a first embodiment of the endo vascular treatment device and a guiding catheter, with the spacer element in expanded position;

- figure 2 a view of the first embodiment of the endo vascular treatment device and guiding catheter, with the spacer element in original unexpanded position;

- figures 3 and 4 schematic views of the endo vascular treatment device and a guiding catheter positioned in a vein; - figures 5-7 are schematic views showing a method of operating the endovascular treatment device, in an initial state, in a state before insertion into a catheter and in a state after insertion respectively; and - figure 8 a schematic view showing different positions of the distal end of the spacer relative to the distal end of the optical fibre.

Figures 1 and 2 show an embodiment of a system 1 for endovascular treatment. The system comprises an optical fibre 2 guided into a passage 9 provided in a guiding catheter 10. In the shown embodiment, a 600 μm fibre is guided into a 6Fr guiding catheter 10, herein also referred to as the (guiding) sheath. The optical fibre 2 includes a core 3 surrounded by a flexible casing 4. Generally the casing 4 includes a cladding layer. The refractive index of the core 3 is greater than that of the cladding layer to confine the optical signal in the core 3. The optical fibre 2 is provided at its proximal end with a connector for connecting the fibre to a laser light source 12 (shown schematically in figure 1). In the neighbourhood of the distal end 5 the cladding layer is absent. Therefore laser energy originating from the laser light source 12 and travelling through the laser fibre core 3 is emitted at the distal end of the fibre.

The optical fibre 2 is provided at its distal end with a spacer element 6. The spacer element 6 may be attached to the fibre using any standard bonding or welding technique known the art. The function of the spacer element is to avoid contact between the wall (W) of the blood vessel in which the fibre is to be arranged, and the fibre tip 5 or even to keep at least a minimal distance between the fibre tip 5 and the vessel wall (W). In the embodiment shown the spacer element 6 is comprised of a plurality of spacer legs 7 extending in a generally longitudinal direction along the distal part of the optical fibre 2. The number of spacer legs 7 may vary and may be selected in accordance with the specific circumstances. In embodiments of the invention the number of spacer legs 7 is between three and ten, but fewer of more spacer legs may be present as well. Furthermore, in the embodiment of figure 1 the fibre 2 is provided with one spacer element 6 only. In other embodiments two or more spacer elements may be provided, for instance at different positions along the fibre.

Each of the spacer legs 6 has a proximal portion 16 attached to the outer surface of the fibre 2 and a distal portion 15, that is not attached to the fibre 2. In the embodiment of figure 1 the spacer element 6 is generally tulip-shaped and the spacer legs 7 have free ends 5 for contacting or engaging the wall (W) of the blood vessel. Referring to figure 1, the length of the legs may vary. The length of the legs relate to the intended diameter of the expanded spacer element, which diameter varies, for instance between 4 and 6 mm. The remaining length of the legs is needed to be able to properly fix the spacer element to the fibre. Typically the length (1) of the legs are in the range of 6-15 mm.

The material of the spacer element 6 should be thermoresistent (up to 200⁰C) to be able to cope with the high temperatures caused by the laser energy emitted from the fibre tip. Furthermore, in embodiments of the invention, the spacer legs 7 are made of memory-material, for instance nitinol or the like. If the legs 7 are pre-curved radially outward, as shown in figure 1 , the legs then have the tendency to expand and to assume this curved shape unless the legs are forced radially inward by mechanical means (to be described hereafter) to an unexpanded position. In embodiments of the present invention the spacer element 6 covers the entire fibre tip 5, while in other embodiments the distal end of the spacer element 6 even extends slightly beyond the distal end of the fibre, that is when the spacer element is in the unexpanded position. Preferably, the spacer element is arranged such that the radial projection (P, cf. figure 1) of the distal ends of each of legs to the fibre is located very close to or at the end of the fibre tip. The spacer element is attached in such a way to the fibre that the radial projection of each of the ends of the spacer element is always positioned within 2 mm, preferably within 1 mm, from the the end of the fibre, (i.e. distance Δ is 2 mm or smaller). The radial projection of ends of the spacer element may be positioned at a location on the tip 5 of the fibre, as is represented by Δ in the upper part of figure 6, while in other embodiments (or in the same embodiment) the radial projection of ends of the spacer element may be positioned beyond the tip 5 of the fibre, as is shown in the lower part of figure 8 (cf. Δ'). The detection of the exact location of the fibre tip 5 is promoted by selecting the material of the spacer element to be of an echogenic type. This helps in positively identifying the position of the fiber tip and therefore further increasing the safety of the procedure.

The fibre 2 with spacer element 2 is arranged in the passage 9 of the guiding catheter 10. When withdrawing the guiding catheter 10 (pullback, direction P₁, figure 1) and/or when advancing the fibre 2 into the guiding catheter 10, the distal end of the spacer element is exposed. This causes the spacer element 6 to expand (in an essentially radial direction P₂, figure 2) from the unexpanded position (cf. figure 2) to the expanded position (cf. figure 1), thereby pushing away the wall (W) of the blood vessel. Due to the shape of the spacer element 6 withdrawal of the fibre 2 from the fiber is possible, while the shape helps to prevent the fiber tip 5 to move further into the blood vessel. The legs 7 of the spacer element in expanded position may extend in a generally oblique manner relative to the longitudinal direction of the fibre. The angle (α) between the longitudinal direction of the fibre and a leg 7 may be substantially constant (for instance in a range from 10 to 60 degrees, preferably between 20 and 45 degrees) or may increase going from the proximal part of the leg to its distal part. The latter situation is depicted in figure 1.

Referring to figures 3 and 4, the spacer element 6 may be designed to prevent the fiber tip from touching the wall (W) of the blood vessel which might cause side-effects such as perforation of the wall of the blood vessel. In further embodiments of the invention the spacer element 6 may be configured to ensure keeping at least a minimum distance between the wall (W) of the blood vessel and the fiber tip 5 while treating the blood vessel with the optical energy from the laser source. More specifically, in e preferred embodiment, the spacer element is configured (shape, position on fibre, etc) to provide for a minimal distance d_r in radial direction (cf. fig 3) and a minimal distance di in longitudinal direction (cf. figure 4). When the fibre tip shape and the position on the fiber are designed to keep a maximum distance the laserbeam from the fibre tip has to travel before the vessel wall is reached, a relatively homogenous heating of the vessel wall may be achieved. More specifically, a more even optical energy distribution may be created in the blood vessel and consequently a more homogeneous destruction of the vessel wall. This more circumferential tissue destruction should lead to a higher occlusion rate, less side-effects like postoperative ecchymosis, inflammation around the treated vein and/or pain.

Referring to figures 5-7, a description is given of one of the modes of operation of the endovascular treatment system according to the above-described embodiments. Figure 5 is a representation of the fibre 2 (provided with a spacer element 6 at its distal end) and a connector 20 attached to the fibre 2 at a predetermined position, when the fibre and connector are still inside the packaging. Figure 6 is a representation of the fibre, spacer element and connector just before insertion into a guiding catheter. Figure 7 is a similar representation wherein the connector 20 of the fibre 2 is attached to the connector 22 of the guiding catheter 10. In this situation the treatment system 1 is ready for use.

In figure 5 the fibre 2 is fitted with a connector 20, for instance a TouhyBorst lock 21. The connector 20 may be attached to another connector 22 attached to the proximal end 24 of the guiding catheter 10. The connector 22 may be a Luerlock type connector 23 shown in figure 6 or a similar device.

The spacer element 6 will be inserted into the guiding catheter using a deployment element 28. In figure 5 one of a variety of embodiments of a deployment element 28 is illustrated. Deployment element 28 in this embodiment is a tubular element, for instance a sleeve-like element, which can be arranged in a close-fitting manner around the spacer element 6 arranged at the distal portion of the fibre 2 so that the spacer element is kept in the unexpanded position.

Inside the packaging the deployment element 28 is kept free from the fibre tip 5 to maintain the expanded position of the spacer element 6 over longer periods of storing and to be able to visually inspect the shape of the spacer element. Before use the deployment element 28, for instance a relatively short sleeve-like element, is arranged over the fibre tip 5 and the spacer element 6 to collapse the spacer element 6 to the unexpanded position so it can be inserted into the proximal end 24 of the guiding catheter 10. The deployment element 28 is pulled back once the spacer element 6 is inside the catheter 10. The deployment element 28 may be accommodated in a hollow space 30 created by the first connector 22 and the second connector 23.

After having inserted the fibre 2 into the guiding catheter 10, one can connect the connectors 20,22 to one another, for instance by screwing the TouhyBorst lock 21 attached to the fibre 2 on the Luerlock 23 attached to the guiding catheter 10. The position of the connector 20 on the fibre 2 is chosen such that the fiber tip 5 with the spacer element 6 just extends from the distal end 25 of the guiding catheter 10 when the connector 20 is connected to the connector 22 of the guiding catheter 10 (cf. figure 7). This positioning of connector 20 on the fibre 2 ensures that the fibre 2 cannot be activated inside the guiding catheter 10, for instance by wrong placement of the fibre initially or by refracting the fibre tip 5 into the guiding catheter 10 during the laser treatment.

To reposition the fibre 2 and guiding catheter 10 it is possible to disconnect the fibre 2 with connector 20 from the other connector 22 on the guiding catheter 10 and slightly pull back the fibre 2 such that the spacer element 6 is inside the catheter passage 9 again.

Although the invention has been described with reference to specific embodiments thereof, it will be appreciated that the invention is not limited to these embodiments and that changes and modifications to the device, system and method described herein may be made without departing from the scope of the invention. The rights applied for are defined by the following claims.

Claims

1. Endo vascular laser treatment device, comprising: - an optical fibre configured to be inserted into a blood vessel and having a distal fibre tip configured to emit laser light locally to treat the inner wall of the blood vessel;

- at least one spacer element fixed to the optical fibre, the spacer element being arranged close to the distal fibre tip and operable to position the distal fibre tip away from the vessel wall, the spacer element being shaped so as to prevent the fibre tip to be advanced further into the blood vessel.

2. Device as claimed in claim 1, wherein the at least one free end of the spacer element is positioned within 2 mm proximal or distal from the the distal end of the fibre, preferably within 1 mm proximal or distal from the distal end of the fibre..

3. Device as claimed in claim 1 or 2, wherein the spacer element is operable to essentially centralise the fibre tip within the vessel.

4. Device as claimed in any of the preceding claims, wherein the spacer element comprises a plurality of self expandable spacer legs, the spacer legs being operatively biased in a radially outward direction.

5. Device as claimed in any of the preceding claims, wherein the spacer element is generally tulip-shaped.

6. Device as claimed in any of the preceding claims, wherein the spacer element is made of shape-memory material and is moveable between a unexpanded position arranged around the fibre and an expanded position extending radially outward from the fibre tip.

7. Device as claimed in any of the previous claims, wherein a spacer leg has a proximal portion attached to the fibre and a distal free portion and wherein the length of the distal portion of the spacer leg is about 2-10 mm, preferably between 4 mm - 6 mm.

8. Device as claimed in any of the previous claims, wherein the spacer element is configured so that the radial projection of the distal end of the spacer element in its expanded position, onto the fibre is located essentially at the end of the fiber tip.

9. Device as claimed in any of the preceding claims wherein the spacer element is in an undeployed state in which the spacer element is essentially unexpanded, while the optical fibre is being inserted into the blood vessel and wherein the spacer element is in a deployed state in which the spacer element is expanded in essentially a radial direction after the optical fibre has been inserted in the blood vessel.

10. Device as claimed in any of the preceding claims, comprising an deployment element that is configured to be arranged around the spacer element to maintain the spacer element in the unexpanded position and to be removed from the spacer element to allow the spacer element to expand to the expanded position.

11. Device as claimed in claim 10, wherein the deployment element is formed by a sleeve that can be arranged over the fibre and the at least one spacer element.

12. Device as claimed in claim 10, wherein the deployment element is formed by the guiding catheter.

13. Device as claimed in any of the preceding claims, comprising a connector for attaching the fibre to a guiding catheter, the connector being fixed to the fibre at a position such that the fibre tip and the at least one spacer element attached to the fibre extend from the distal end of the guiding catheter when the fibre is attached to the guiding catheter.

14. Device as claimed in any of the preceding claims, wherein the spacer element is made of echogenic material.

15. System for endo vascular treatment, comprising:

- an endo vascular laser treatment device as claimed in any of the preceding claims; - a guiding catheter configured to be inserted into the blood vessel and having a passage for insertion of the laser treatment device..

16. System as claimed in claim 14, the guiding catheter and fibre comprising a first connector and second connector respectively for releasably attaching the guiding catheter to the optical fibre, wherein the second connector is fixed to the fibre at a position such that the fibre tip and the at least one spacer element extend from the distal end of the guiding catheter when the first connector is attached to the second connector.

17. System as claimed in claim 16, wherein the sleeve is formed by a pusher element when the fibre is not inserted into the guiding catheter and the sleeve is formed by the guiding catheter when the fibre is inserted into the guiding catheter.

18. System as claimed in any of claims 16-17, wherein the first and second connectors define an interior space that is shaped and dimensioned to accommodate the pusher element when the connectors attach the fibre to the guiding catheter.

19. System as claimed in any of claims 17-20, wherein the first connector and pusher element are configured to essentially maintain the at least once spacer element in the unexpanded position while inserting the fibre tip from the pusher element into the guiding catheter.

20. Method of operating a system comprising an endo vascular treatment device, the method comprising:

- providing a guiding catheter configured to be inserted into a blood vessel and having a passage for insertion of an optical fibre having a distal fibre tip configured to emit laser light locally to treat the inner wall of the blood vessel and at least one spacer element arranged close to the distal fibre tip; - arranging a deployment element around at least a part of the at least one spacer element to maintain the spacer element in an undeployed state;

- inserting the distal fibre tip into the passage in the guiding catheter while keeping the spacer element in the undeployed state; - advancing the fibre through the guiding catheter so that the spacer element of the fibre extends beyond the distal end of the guiding catheter and expands to the deployed state.

21. Method as claimed in claim 20, wherein the endovascular treatment device is a device as claimed any of the preceding claims.