WO2011015218A1

WO2011015218A1 - Catheter with two fenestrations

Info

Publication number: WO2011015218A1
Application number: PCT/EP2009/005686
Authority: WO
Inventors: Miles Dalby
Original assignee: Ls Medcap Gmbh
Priority date: 2009-08-06
Filing date: 2009-08-06
Publication date: 2011-02-10

Abstract

The present invention relates to a Catheter (17) for insertion into a body lumen (11), the catheter having a catheter sleeve (18) comprising a distal section (19) configured to at least temporarily assume an essentially helical or spiral shape, and a first fenestration (20) at the distal end (21) of the catheter (17). The catheter sleeve (18), further, comprises a second fenestration (22) provided proximal to the first fenestration (20), said distal section (19) being provided between said first fenestration (20) and said second fenestration (22). The distal section (19) is configured to assume the essentially helical or spiral shape such that the second fenestration (22) is essentially centred to the body lumen (11) when said catheter (17) is inserted into the body lumen (11).

Description

Catheter with two fenestrations

The present invention relates to a catheter for insertion into a body lumen, the catheter being inserted into the body lumen in that it is pushed over a guide wire that has already been inserted into the body lumen and serves as a guide for the catheter.

Such catheters are well know and are e.g. being used for stent graft placement, cardiological catheterization techniques, angiographic procedures, and the like more. Although placement of such catheters according to the so-called Seldinger-technique has been used since many years, there exist still certain drawbacks with such prior art guide wires and catheters.

Namely, standard guide wires as well as normal catheters do not provide a reliable means for navigating through constrictions with small residual openings. A good example for such a constriction is an aortic valve, in particular a stenosed aortic valve, which owing to calcification can no longer fully open, leaving just a small opening essentially centred to the cross-section of the aorta.

When a standard guide wire is advanced towards a constriction, it will in most cases hit the barrier of the constriction instead of the residual opening. This is even more the case, when the guide wire proximal to the constriction follows a curved section of a body lumen like, for example, the aortic arch. In this situation, the tip of the guide wire, owing to the guide wire's inherent stiffness, tends to follow that part of the body lumen's border describing the widest radius. This position is, however, in most cases not the position of the residual opening. Although the position of the wire can be modified with pre-shaped catheters, these usually need significant manipulation to achieve a successful wire position. Consequently, constrictions like stenosed aortic valves can be difficult and time consuming to cross using standard guide wires and catheters.

In order to solve this problem, GB 2 399 017 A discloses a catheter that can be used to direct the tip of a guide wire to a centred position with respect to the cross section of a body lumen.

This catheter has a catheter sleeve comprising a pre-shaped distal section, adjusted to temporarily forming a helix, a first lumen, which accommodates a first guide wire, a second lumen, accommodating a straightening element, and an opening at the distal catheter tip, this distal opening being centred to the cross section of the helix once the distal section forms a helix. After having been advanced via the guide wire towards a constriction, the catheter is actuated by retracting the straightening element such that the distal section forms a helix and centres the distal opening within the body lumen. The helix is supported against the borders of the body lumen and the guide wire can be advanced through the helix and the opening of the catheter into a centred residual opening of the constriction.

However, even when using a catheter of the known kind, crossing, for example, a stenosed aortic valve is still very complicated and is often very time consuming even for very experienced operators. This is mainly due to the fact that such known catheters often can not be redirected in a precisely defined manner, leading to a situation, where the correct initial positioning of the catheter tip alone is essential for the operational success.

Moreover, in cases, where the residual opening is offset from the centre of the body lumen's cross section, the known catheters may be unsuitable.

This is the case because the known solution just provides means for centring the distal opening and thus the guide wire to the body lumen. It does not provide, however, sufficient flexibility in order to redirect the guide wire to a position offset from the centre of the lumen. Therefore, the operator has virtually no means of adjusting or correcting the position or entry angle of a guide wire into the residual opening of the constriction after the catheter has been helically expanded and its distal opening thus centred.

Under such circumstances, the guide wire will with a high probability miss the opening, thus contacting the constriction itself, for example the leaflets of an aortic valve. In this situation, operators repeatedly advance the guide wire towards the constriction, thereby trying to alter the position of the guide wire tip by attempting to move or twist the catheter. As the possibilities of repositioning the known catheter are very limited, crossing of constrictions is frequently unsuccessful. In such cases, the catheter has to be fully retracted and exchanged.

Even if crossing of the constriction is successful, the abovementioned deficits in usability of the known catheter lead to results, which, from the medical point of view, are frequently unsatisfactory.

In the case of stenosed aortic valves to be crossed, this is due to the fact that a high number of attempts are often made to find and cross the residual opening. Each of the repeated trial pushes of the guide wire against the calcified aortic valve may result in the loosening of particles of calcified matter. These particles are then carried away in the blood stream and can clog blood vessels in many organ systems.

After retrograde passage of guide wires through stenosed aortic valves, using conventional catheters, particles of calcified matter appear to cause acute cerebral embolic events very frequently, as reported by Omran et al., Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study, Lancet 2003, Apr 12;361(9365):1241-6). In their study, the authors have found a ratio of 22% of patients that, having been subjected to catheterization through aortic valves, exhibited focal diffusion imaging abnormalities in a pattern consistent with acute cerebral embolic events. A total of 3% of the patients showed clinically apparent neurological deficits.

In addition to the embolic risks of repeated attempts at aortic valve crossing, this process is time consuming and results in excess x-radiation exposure to the patient.

Thus, the present solutions for crossing calcified aortic valves are highly unsatisfactory from the medical point of view.

In view of the above, it is an object of the invention to improve the known catheters in such a way that, while still being initially essentially centred, the guide wire can more flexibly and precisely be directed to varying positions in the plane of the constriction.

In the case of the catheter mentioned at the outset, this object and other objects are achieved according to the invention in that the catheter has a catheter sleeve comprising a distal section configured to at least temporarily assume an essentially helical or spiral shape, a first lumen for accommodating a first guide wire, a second lumen for accommodating a second guide wire, a third lumen for accommodating a first shaping element, and a first fenestration at the distal end of the catheter, connecting to the fist, second and/or third lumen, whereby the catheter sleeve comprises a second fenestration provided proximal to the first fenestration, said distal section being provided between said first fenestration and said second fenestration, the second fenestration connects to the first, second and/or third lumen, and the distal section is configured to assume the essentially helical or spiral shape such that the second fenestration is essentially centred to the body lumen when said catheter is inserted into the body lumen.

The main difference, compared to GB 2 399 017 A, is that, with the prior art catheter, the fenestration, through which the guide wire to be inserted into the residual opening of a constriction leaves the catheter, is provided distal to the helical or spiral shaped section. Therefore, neither the position of the fenestration with respect to the centre of the body lumen nor the angle, at which the guide wire exits the fenestration with respect to the longitudinal axis of the body lumen, can be altered.

Within the scope of the present invention, a "guide wire" is a wire used for catheter placement according to the Seldinger-technique. For this purpose, the guide wire is inserted into a body lumen, for example a blood vessel, prior to advancing a catheter. The catheter is then advanced into the body lumen, whereby it is guided by the guide wire accommodated in the lumen or the lumina of the catheter. A "shaping element", within the scope of the present invention, is an element slidably accommodated in a lumen of the catheter sleeve, which element is configured to change the shape of the catheter, in particular the distal section.

The shaping element may have a straight form. Hence, when the shaping element is inserted into a catheter lumen, it straightens the catheter sleeve.

Alternatively, the shaping element may have, at least in part, a helical or spiral shape. Hence, when such shaping element is present inside a catheter lumen, the catheter sleeve adopts a helical or spiral shape.

In this connection, a helical or spiral shaping element has to be flexible enough to be straightened by counter pressure, for example exerted on it by a straight shaping element or a guide wire present in a parallel catheter lumen.

A "shaping element" must not necessarily be a continuous wire or tube, also other structures my be used as long as such structures fulfil the purpose of the shaping element as discussed in detail within this application.

According to the invention, the fenestration, through which a guide wire may be advanced in direction towards the residual opening of a constriction, may be a simple opening or a more complex structure, like an outlet or port, allowing at least one lumen inside the catheter sleeve to communicate with the exterior.

The essentially helical or spiral shape assumed by the distal section generally describes at least one full circle in direct attachment with the borders of the body lumen. This way, the borders of the body lumen, for example the walls of the aorta, pose a counter pressure to the distal section from all sides alike, thereby centring the catheter and thus the second fenestration. In this connection, the term "essentially helical or spiral shape" also includes shapes that may, for example, result from lengthwise compression of a helix or spiral, namely annular or circular shapes.

Further, the distal section comprises a proximal part, leading essentially towards the centre of the body lumen. This proximal part may have the shape of a tighter spiral or helical coil or, alternatively, may be formed as a centring shaft.

Within the scope of the present invention, such centring shaft is a straight, relatively rigid structure adjoined by more flexible regions, allowing easy adjustment of the position of the second fenestration with respect to the plane of the constriction in any direction. Even tilting the exit vector through the second fenestration is made possible.

Further, according to the invention, the expression "upstream", with respect to a blood vessel, describes the direction opposing the blood flow, while the expression "downstream" describes the direction following the blood flow.

The expression "proximal", with respect to a catheter, describes the direction towards an operator handling the catheter, while the expression "distal" describes the direction towards the catheter tip, facing away from the operator.

According to the invention, the body lumen may be, but is not limited to, an aorta, the constriction being for example an aortic valve.

The following description relates exclusively to this example. It goes, however, without saying that the devices and methods according to the present invention may also be used in connection with other body lumina, like constituents of the blood vessel system, the urogenital, digestive or respiratory tract, and with other types of constrictions occurring in the blood vessel system, the urogenital, digestive or respiratory tract. According to a first embodiment, the novel catheter comprises a preformed catheter sleeve adjusted to assuming, in the distal section, an essentially helical shape with a proximal centring shaft. The shaping element, in this connection, acts as a straightening element. In other words, as long as the straightening element is inserted into a lumen of the catheter and running through the distal section, the distal section is straight.

When using this catheter, a first guide wire is advanced towards the aortic valve at the beginning of the intervention. Then the novel catheter, with the shaping element inserted into the second lumen, is advanced towards the aortic valve via the first guide wire that is accommodated within the first lumen. When the catheter reaches the position of the aortic valve, the shaping element is retracted from the second lumen and the distal section assumes its essentially helical shape.

The centring shaft now leads to the centre of the aorta, maintaining a certain distance in between the second fenestration and the residual opening of the aortic valve. Therefore, it allows shifting the position of the second fenestration with respect to the plane of the aortic valve in any direction.

Thus, the operator can influence the position of the second fenestration with respect to the centre of the aorta by twisting and turning as well as pushing and pulling the catheter.

At this stage, the tip of a second guide wire is advanced via the third lumen and through the second fenestration. The operator adjusts the position and angle with respect to the residual opening to be passed and inserts the second guide wire through the residual opening.

Then, the catheter is straightened by re-inserting the shaping element. After this, catheter and first guide wire are retracted, leaving the second guide wire within the aorta and the residual opening of the aortic valve to direct a follow-up catheter through the aortic valve. Hence, using the novel catheter, the success of crossing the aortic valve is greatly increased. Further, a high number of trial pushing of the guide wire against the aortic valve is avoided.

Thus, the insertion of a guide wire through an aortic valve can be performed in a comparably quick and secure manner even in cases, where the opening of the aortic valve is offset from its centre.

A further advantage is that the second guide wire to be inserted through the aortic valve can be advanced facing greatly reduced opposing frictional forces, as compared to the catheter of GB 2 399 017 A.

According to the invention, the second guide wire does not have to follow the helical or spiral coil of the catheter, but remains rather straight and is advanced directly from the more or less straight catheter shaft through the second fenestration in direction towards the residual opening of the aortic valve to be passed.

This reduction of frictional force makes the operation of the catheter more easy and convenient for the operator and, further, reduces the risk of the operation, because the novel construction prevents the guide wire from advancing with a sudden jerk, when the force imposed by the operator suddenly exceeds the frictional force opposing.

The novel catheter hence allows the insertion of a guide wire through an aortic valve in a much more defined and controllable manner.

The object underlying the invention is achieved completely in this way.

According to a second embodiment, it is preferred if the first lumen serves also as the third lumen and the first guide wire serves also as the first shaping element. In this configuration, the catheter bears two lumina, a first (and third) lumen accommodating the first guide wire, which first guide wire, due to its inherent stiffness, also acts as a straightening element, and a second lumen accommodating the second guide wire and connecting to the second fenestration. Further, in the region of the distal section, the catheter sleeve is preformed in order to at least temporally assume a helical or spiral conformation.

When inserting such a catheter into the aorta, the stiffness inherent to the guide wire is used to keep the catheter-sleeve straight. When the distal section is to assume its helical or spiral conformation, either the first guide wire is retracted or the catheter sleeve is advanced beyond the distal tip of the first guide wire. After the distal section has assumed its helical or spiral conformation, the second fenestration is centred to the aortic valve.

The second guide wire can then be inserted into the second lumen and through the second fenestration, and further through the residual opening of the aortic valve. In order to retract the catheter, the distal section has to be re-straightened. In this embodiment, this is achieved by reinsertion of the first guide wire (first shaping element) into the first lumen.

The advantage of this embodiment is that the catheter design is simplified as compared to the design with three lumina. The simplification of the catheter design affords a reduction of the production costs. Also, the diameter of the catheter can be reduced, reducing also its overall stiffness.

Moreover, the handling of the catheter is simpler because one element less has to be actuated by the operator. Additionally, the surface reduction, which is due to the reduced diameter, results in a reduced danger of thrombus formation at the catheter surface.

According to a third embodiment, it is preferred, if the first lumen serves also as the second lumen and the first guide wire serves also as the second guide wire. Also in this configuration, the catheter bears two lumina, the first (and second) lumen accommodating the one guide wire and the third lumen accommodating the first shaping element. In this case, the second fenestration connects to the first lumen.

In this embodiment, there exist two alternatives concerning the parts of the catheter responsible for the formation of the helix.

According to a first alternative variant of the third embodiment, the catheter sleeve itself is preformed to at least temporally assume a helical conformation. The first shaping element in this case acts as a straightening element, keeping straight the distal section as long as it is fully inserted.

During insertion, the catheter is kept straight by the shaping element. When the distal section is to assume its helical or spiral conformation, the shaping element is retracted. After the distal section has assumed its helical or spiral conformation, the second fenestration is centred to the aortic valve. Then, the one guide wire is retracted to a position proximal to the second fenestration.

When re-advancing this single guide wire, it exits the catheter sleeve through the second fenestration, due to the curvature of the catheter. The guide wire can then be further advanced through the residual opening of the aortic valve. In order to re- straighten the catheter, prior to its retraction from the aorta, the shaping element is re-advanced into the third lumen.

According to a second alternative variant of the third embodiment, the catheter sleeve is flexible. The first shaping element in this case is preformed to at least temporally assume a helical or spiral conformation.

When inserting such a catheter into the aorta, the stiffness inherent to the one (single) guide wire is used to keep the first shaping element and consequently the catheter-sleeve straight. When the distal section is to assume its helical or spiral conformation, either the one guide wire is retracted or the catheter sleeve is advanced beyond the distal tip of the guide wire.

After the distal section has assumed its helical or spiral conformation, the second fenestration is centred to the aortic valve. Again, the single guide wire can be pushed through the second fenestration and further inserted through the residual opening of the aortic valve.

In order to re-straighten the catheter, in this case, the first shaping element is retracted to a position proximal to the second fenestration. The first shaping element, now being juxtaposed to the single guide wire inside the catheter sleeve, is hence straightened. Accordingly, the catheter sleeve distal to the second fenestration is no longer formed by the first shaping element and, owing to its flexibility, assumes a relaxed conformation suitable for retraction of the catheter.

In any case, combining the two lumina and using one instead of two guide wires is advantageous, resulting in a simplification of the catheter design and catheter use.

It is also preferred, if the first shaping element, when fully inserted into said third lumen, is adjusted to straightening the distal section in longitudinal direction and/or that the distal section of the catheter sleeve is preformed for at least temporarily assuming an essentially helical or spiral shape.

It is, in this connection, of course desirable for the catheter sleeve to be preformed in order to form for example a centring shaft as well.

Further, according to a fourth embodiment, it is preferred, if the catheter comprises a fourth lumen for accommodating a second shaping element. Preferably, the second shaping element is adjusted at its distal end to at least temporarily assuming an essentially helical or spiral shape. In this embodiment, the catheter sleeve is flexible at least in the region of the distal section, the second shaping element being preformed in order to at least temporally assume an essentially helical or spiral shape whereas the first shaping element acts as a straightening element.

Thus, when the first shaping element is retracted, the second shaping element can adopt a helical or spiral shape, shaping as well the catheter. To re-straighten the catheter, the second shaping element is then retracted as well.

The advantage here is that all steps of shaping the catheter are brought about by retracting the shaping elements. This configuration makes the use of the catheter extremely simple. Further, owing to the fact that no direct friction between the tip of the first shaping element and the catheter sleeve occurs, the risk of the first shaping element penetrating the catheter sleeve when being re-advanced into the distal section can be avoided.

Generally, it is preferred, if the first shaping element and/or the second shaping element are comprised of shape-memory material.

Such materials, for example nitinol, are extensively known from the prior art. In the context of the present invention, it is conceivable to use a material, that, responsive to external cues like temperature or electric current, changes its shape either to form a helix or spiral or to form a straight line.

It is preferred as well, if the catheter comprises a lumen, which can guide a liquid.

Such a liquid-guiding lumen can be used to transport, for example, radiopaque contrast media in direction towards the position of the distal end of the catheter. Such lumen can be a further lumen or one of the lumina used for guide wires and/or shaping elements. In this connection, it is of course possible to design the further lumen in such way, that it has, preferably in the range of the distal section, at least one, preferably a number of openings, connecting it with the aorta.

The advantage of such a catheter with a liquid guiding lumen is that it makes visualizing the position and spatial orientation of the aortic valve easier.

A problem, often occurring when replacing calcified aortic valves with endoluminal valve prostheses, is that the spatial orientation of the aortic valve, using X-Ray in connection with contrast media, cannot be visualized appropriately.

As any faulty determination of the aortic valve's spatial orientation may lead to misplacement of the endoluminal valve prosthesis and, hence, to incomplete coverage of the leaflets of the calcified aortic valve, the correct determination of the aortic valve's spatial orientation is decisive for the successful placement of the endoluminal valve prosthesis.

When injecting radiopaque liquid into the liquid guiding catheter lumen, the catheter becomes radiopaque. Hence, when the catheter is pushed against the annulus formed by the aortic valve, it marks the position and tilt of the aortic valve in a reliable manner. The operator can hence, even using conventional X-Ray devices for visualization, exactly determine the position and tilt of the aortic valve with respect to the visualized plane.

When contrast medium is injected into the aorta via the novel catheter, it will not only mark the outer limits of the aorta as well as position and tilt of the aortic valve, but may as well indicate the position of the residual opening of the calcified aortic valve. This is because the jet of blood emitted through the residual opening does not contain any radiopaque contrast medium, therefore being visible as a region of decreased X-Ray density. Furthermore, a liquid carrying lumen can also be used to inject medication into the blood stream. Such medication, in the context of the present invention, may be for example heparin or other agents counteracting blood clotting at or in the vicinity of the catheter and/or the guide wire.

In this connection, it is understood that the concept of a visualization catheter with a shaping mechanism for its distal section according to any of the embodiments described above and with a liquid guiding lumen is new and inventive also on its own as it can be used independent of placing a guide wire.

In a fifth embodiment, further specifying the catheter according to the first embodiment mentioned above, the present invention relates to a catheter for insertion into a body lumen, the catheter having a catheter sleeve comprising a distal section preformed for at least temporarily assuming an essentially helical or spiral shape, a first lumen for accommodating a first guide wire, a second lumen for accommodating a second guide wire, a third lumen for accommodating a first shaping element, said shaping element, when fully inserted into said third lumen, being adjusted to straightening the distal section in longitudinal direction, a first fenestration at the distal end of the catheter, connecting to the first, second and/or third lumen, and a second fenestration provided proximal to the first fenestration, said distal section being provided between said first fenestration and said second fenestration.

As already discussed above, such catheter is technically straight-forward and easy to use. Due to the fact that two different guide wires are accommodated within the catheter sleeve, the catheter allows rapid placement of a guide wire through the residual opening of an aortic valve even in cases, where the guide wire used for catheter advancement and the guide wire for crossing the residual opening differ from each other.

According to a sixth embodiment, further specifying the catheter according to the third embodiment mentioned above, the present invention relates to a catheter for insertion into a body lumen, the catheter having a catheter sleeve comprising a distal section which is flexible in order to permit it to at least temporarily assume an essentially helical or spiral shape, a first lumen for accommodating a first guide wire, a second lumen for accommodating a first shaping element, said shaping element being adjusted at its distal end to at least temporarily assuming an essentially helical or spiral shape, a first fenestration at the distal end of the catheter, connecting to the first and/or second lumen, and a second fenestration provided proximal to the first fenestration, said distal section being provided between said first fenestration and said second fenestration.

The advantage of such a catheter is that the re-straightening of the catheter is brought about by retraction of the second shaping element. The danger of a straightening element penetrating the catheter sleeve when being re-advanced is, therefore, avoided.

Further, this catheter has only two lumina and two structural elements (guide wire, shaping element), making easier its use and reducing its production costs.

In addition, the present invention concerns methods of advancing a guide wire through a constriction of a body lumen, preferably an aortic valve, using the catheters described above.

In a first variant, said method comprises the steps of a) advancing the first guide wire towards the constriction, b) advancing the catheter towards the constriction via the first guide wire, c) allowing the distal section to assume an essentially helical or spiral shape, d) advancing the second guide wire so that it exits the catheter sleeve through the second fenestration, e) advancing the second guide wire through the constriction, f) straightening and/or relaxing the catheter sleeve, and g) retracting the catheter from the body lumen. In a second variant, said method comprises the steps of a) advancing the first guide wire towards the constriction, b) advancing the catheter towards the constriction via the first guide wire, allowing the distal section to assume an essentially helical or spiral shape by advancing the catheter sleeve beyond the distal end of the first guide wire, c) advancing the second guide wire so that it exits the catheter sleeve through the second fenestration, d) advancing the second guide wire through the constriction, e) retracting the catheter sleeve over the first shaping element in order to straighten the distal section, and f) retracting the catheter from the body lumen. In a third variant, said method comprises the steps of a) advancing the first guide wire towards the constriction, b) advancing the catheter towards the constriction via the first guide wire, allowing the distal section to assume an essentially helical or spiral shape by advancing the catheter sleeve beyond the first guide wire, such that the tip of the first guide wire comes to lie proximal to the second fenestration, c) advancing the first guide wire so that it exits the catheter sleeve through the second fenestration, d) retracting the shaping element so that the distal section is relaxed, and e) retracting the catheter from the body lumen.

Again, the advantage is that, using the novel method, guide wires can be inserted through residual openings of body lumina with greater ease. This is due to the improved maneuverability of the guide wire, which results from the guide wire exiting the catheter sleeve through the second fenestration. Moreover, the risk caused by loosened calcified particles is reduced.

Using the novel catheter with preformed catheter sleeve, one straightening element and two guide wires, the method allows to rapidly place a guide wire of choice for example through a calcified aortic valve.

If a catheter is used that comprises a flexible catheter sleeve, a shaping element, adjusted at its distal end to at least temporarily assuming an essentially helical or spiral shape, and a single guide wire, one advantage of the method is the avoidance of risks associated to potential catheter sleeve penetration by shaping elements.

Further, a supplemental invention concerns a Catheter for visualizing the spatial orientation of a constriction inside a body lumen, the catheter having a catheter sleeve comprising a distal section configured to at least temporarily assume an essentially helical or spiral shape, a first lumen for accommodating a first guide wire, a second lumen for accommodating a first shaping element, a third lumen for accommodating a radiopaque material, and a first fenestration at the distal end of the catheter, connecting to at least the first lumen. In this connection, the shaping mechanism for the distal section and the distal section itself may be designed according to anyone of the embodiments described above in connection with the catheter for guide wire placement.

It is preferred, if the third lumen is adjusted for receiving a liquid and that the radiopaque material is a radiopaque liquid.

Hence, the radiopaque liquid, being present inside the third lumen, makes radiopaque the catheter itself. This way, the position and tilt of the aortic valve with respect to the plane of X-Ray visualization can be easily determined.

It is also preferred, if the catheter sleeve comprises, in the region of the distal section, two or more openings connecting to the third lumen.

Hence, radiopaque liquid and/or medication can be injected into the aorta such that it is distributed very fast. Thus, the entire aortic lumen can be visualized and also the jet of blood ejected through the residual opening of the aortic valve can be made visible.

According to a preferred embodiment of the supplemental invention, the third lumen accommodates at least one solid radiopaque marker.

Radiopaque markers may, alone or in combination with radiopaque liquid injected into the third lumen, serve to visualize the position and tilt of the aortic valve with respect to the plane of X-Ray visualization.

These markers may be either continuous or consist of several individual markers, distributed along the circumference of the helix or spiral formed by the distal section. The "third lumen" may in this connection not necessarily be an elongated internally running channel but be comprised of several lateral indentations, i.e. externally accessible openings within the outer wall of the catheter sleeve, which openings may contain each a piece of radiopaque material. In particular, radiopaque markers may also serve to indicate the orientation of the distal section. When the distal section is compressed against the aortic valve, it may be visible, using an X-Ray imaging device, as an annular structure. When this annular structure is more or less symmetric between front and aft side, it is not possible to determine, which of its sides is facing the operator and which side is facing away from the operator. Accordingly, the annular structure and, respectively, the aortic valve still may have two different orientations with respect to the plane of visualization, which orientations cannot be distinguished from each other.

Solid radiopaque markers provided in the third lumen can be configured such that the possible orientations of the annular distal section can always be distinguished. For this reason, the radiopaque markers may be asymmetric with respect to the annular structure, marking, for example, a first position on the annular structure and, further, marking a second position, preferably approximately 90° radian measure apart from the first position. Moreover, the two marks may be visually distinct from each other, providing an even better distinction of the annular structure's possible orientations.

According to a further embodiment of the supplemental invention, the distal section is configured such that, when said distal section has assumed its essentially helical or spiral shape, said catheter sleeve, proximal to distal section, is offset from the centre of body lumen.

In this connection, the proximal part of the distal section, which proximal part in the catheter for guide wire placement leads essentially towards the centre of the body lumen, may, in the context of the novel visualization catheter, be shorter or may not be provided at all.

Hence, the visualization catheter does not interfere with the placement of another catheter through the residual opening of the aortic valve. Further, the supplemental invention concerns a respective method of visualizing the spatial orientation of an aortic valve using the novel visualization catheter.

Still further, the invention concerns a kit comprising a catheter for the insertion of a guide wire through a constriction inside a body lumen and a catheter for visualizing the spatial orientation of constriction inside a body lumen.

Further advantages follow from the description and the attached figures.

It goes without saying that the features named above and those still to be explained below can be used not only in the respectively specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

Several embodiments of the invention are illustrated in the figures and explained in more detail in the following description. In the Figures:

Fig. 1 shows in schematic sectional view an aorta with an aortic valve, a guide wire being inserted therein;

Fig. 2 shows a schematic sectional view of the aorta of Fig. 1, wherein a catheter is inserted into the aorta via the guide wire;

Fig. 3 shows a first embodiment of the catheter of Fig. 2 in cross-section along plane A;

Fig. 4 shows a second embodiment of the catheter of Fig. 2 in cross-section along plane A;

Fig. 5 shows a third embodiment of the catheter of Fig. 2 in cross-section along plane A; Fig. 6 shows a fourth embodiment of the catheter of Fig. 2 in cross-section along plane A;

Fig. 7 shows the catheter of Fig. 2, wherein the distal section has assumed a helical shape;

Fig. 8 shows the catheter as in Fig. 7, wherein a second guide wire has been inserted through the aortic valve;

Fig.9 shows the aorta as in Fig. 8, wherein the catheter has been retracted and a second catheter has been partly advanced towards the aortic valve via the second guide wire;

Fig. 10 shows in partial sectional view the catheter according to the second embodiment prior to assuming a helical shape;

Fig. 11 shows the catheter of Fig. 10, wherein the catheter is in the process of assuming a helical shape at its distal section;

Fig. 12 shows the catheter of Fig. 11, wherein the catheter has assumed a helical shape at its distal section;

Fig. 13 shows the catheter as in Fig. 12, wherein the second guide wire has been advanced through the second opening;

Fig. 14 shows the catheter of Fig. 13, wherein the distal section has been re- straightened;

Fig. 15 shows, in partial sectional view, an aortic valve, the visualization catheter according to the supplemental invention having been advanced thereto, Fig. 16 shows in top view, as seen in distal to proximal direction, the visualization catheter;

Fig. 17 shows an aortic valve, the visualization catheter according to a second embodiment of the supplemental invention having been advanced thereto; and

Fig. 18 shows, in partial sectional view, the aortic valve and the visualization catheter as in Fig. 17, but from a shifted perspective.

Fig. 1, which like the following Fig. 2 to 16 is not drawn to scale, shows in a perspective view a guide wire 10 placed in an aorta 11 comprising aortic walls 12, a side vessel 13 as well as an aortic valve 14.

Aortic valve 14 has a residual opening 15, which is lying approximately centred to a longitudinal axis 16 of aorta 11.

For the replacement of a calcified aortic valve 14, a catheter with an endoluminal prosthesis adjusted for functional replacement of the aortic valve 14 has to be inserted through the residual opening 15 of the calcified aortic valve 14.

This intervention is usually carried out, using a guide wire for catheter placement according to the Seldinger-technique. For this purpose, a guide wire is inserted into aorta 11 and subsequently must be placed through residual opening 15 of aortic valve 14.

The optimal entry vector for guide wire through the residual opening here is indicated by an arrow 16.

Fig. 1 illustrates the problem underlying the present invention. Placed in aorta 11, guide wire 10 is shown. Guide wire 10, crossing the aortic arch, is bent against its inherent stiffness. When being inserted, guide wire 10, with its tip, will follow the aortic walls 12 in a manner allowing it to bend as little as possible. Therefore, instead of being centred to the lumen of aorta 11, the tip of guide wire 10 is positioned adjacent to the part of the aortic walls 12 featuring the widest curvature.

This is also the case, when guide wire 10, with its tip, approaches aortic valve 14.

In order to cross aortic valve 14, however, guide wire 10 must pass the residual opening 15 following a vector, corresponding the optimal vector indicated by the arrow 16.

As follows from the difference between the actual position of guide wire 10 and the desired position in the centre of residual opening 15 of aortic valve 14, it is very difficult, if not impossible, to cross aortic valve 14 without a mechanical aid, translocating guide wire 10 to the centre of aorta 11 and hence to the position of residual opening 15.

With respect to this problem, the present provides means for translocating guide wire 10 to the centre of aorta 11, thus facilitating the insertion of guide wire 10 through residual opening 15 of aortic valve 14.

When using the novel catheter, a guide wire 10 is inserted into aorta 11 in a conventional manner, until it approaches with its tip, aortic valve 14. At this point, the situation exactly corresponds to the situation shown in Fig. 1.

The coordinate system in the lower right corner indicates the distribution of spatial axes with respect to aortic valve 14, whereby XY is a plane parallel to the plane of aortic valve 14, whereas planes XZ and YZ are parallel to a longitudinal axis 16 of aorta 11. Also in the following figures coordinate systems in the lower left or lower right corners indicate the plane corresponding to the shown perspective.

Fig. 2 shows a sectional side view of aorta 11, wherein a catheter 17 has been advanced into aorta 11 via guide wire 10.

Catheter 17 comprises a catheter sleeve 18 with a distal section 19, a first fenestration 20, which is present at the distal end 21 of catheter sleeve 18, and a second fenestration 22.

When catheter 17 is advanced into aorta 11 using the Seldinger-technique, guide wire 10 enters the lumen of catheter 17 via first fenestration 20 at distal end 21.

Distal section 19, which has as its distal border distal end 21, its proximal border being marked by a dotted line, is the section of the catheter, which in a later process will assume a helical or spiral conformation.

At the time of insertion of catheter 17 into aorta 11, however, distal section 19 is still in a straight form.

Second fenestration 22, which at a later point will serve the exit of a guide wire from catheter sleeve 18 and the insertion of a guide wire through residual opening 15 of aortic valve 14, is located close to the proximal border of distal section 19.

Dashed line A indicates the plane of the cross sections shown in following Fig. 3 to 6.

Fig. 3 shows a cross section of catheter 17 according to a first embodiment of the present invention, the plane of the cross section corresponding to plane A as indicated in Fig. 2. Catheter 17 comprises catheter sleeve 18, having, in this embodiment, three lumina. Guide wire 10 is accommodated in a lumen 23, a second guide wire 24 is accommodated in a lumen 25, and a first shaping element 26 is accommodated in a lumen 27.

In this connection, catheter sleeve 28 may be, in the region of the distal section 19 of Fig. 2, pre-shaped in order to assume a helical or spiral shape.

In this case, shaping element 26 has a straight form, straightening the catheter, when fully inserted in lumen 27.

Hence, when shaping element 26 is withdrawn from lumen 27, catheter 17 assumes a helical conformation in the region of distal section 19 of Fig. 2.

When shaping element 26 is inserted again into lumen 27, catheter 17 is stretched again into a straight form.

Alternatively, catheter sleeve 18 may be flexible, in the region of distal section 19 of Fig. 2.

In this case, shaping element 26 is pre-shaped in order to assume a spiral or helical conformation when facing reduced counter pressure. In this connection, counter pressure, keeping shaping element 26 and, hence, catheter 17 straight, is exerted by guide wire 10.

Thus, when guide wire 10 is withdrawn from distal section 19 of Fig. 2, shaping element 26 shapes the flexible catheter sleeve 18 into a spiral or helical shape. When withdrawing also shaping element 26 from distal section 19 of Fig. 2, catheter sleeve 18 is again brought into a relaxed, flexible form, suitable for retraction of catheter 17. Fig. 4 shows catheter 17 according to a second embodiment of the present invention in cross section, whereby the plane of the cross section corresponds to plane A, as indicated in Fig. 2.

Catheter 17 comprises a catheter sleeve 18', having, in this embodiment, only two lumina. A lumen 23' accommodates a guide wire 10', which guide wire 10' also serves as a shaping element. Further, second guide wire 24 is accommodated in lumen 25.

Catheter 17 according to the second embodiment, hence, combines in lumen 23', functionally corresponding to lumina 23 and 27 of the first embodiment, the functionalities of guide wire 10 and first shaping element 26 from Fig. 3.

In this context, catheter sleeve 18' is pre-shaped in order to assume a helical or spiral conformation in the region of distal section 19 of Fig. 2. Guide wire 10', in this context, serves as well a shaping element, which, when inserted in first lumen 23', keeps in straight form catheter sleeve 18'.

Hence, when first guide wire 10' is retracted from distal section 19 of Fig. 2, catheter sleeve 18', in the distal section 19 of Fig. 2, assumes a helical or spiral conformation. Upon reinsertion of guide wire 10' into distal section 19 of Fig. 2, catheter sleeve 18' is again brought into a straight form.

Fig. 5 shows catheter 17 according to a third embodiment in cross section, the plane of the cross section corresponding to plane A as indicated in Fig. 2.

In this embodiment, catheter 17 comprises a catheter sleeve 18", having, similar to the second embodiment shown in Fig. 4, only two lumina. Lumen 23", functionally corresponding to lumina 23 and 25 of the first embodiment, houses first guide wire 10". Lumen 27 accommodates shaping element 26. The difference when comparing the first and the third embodiment is that in the third embodiment guide wire 10" functionally replaces guide wire 24. Accordingly, guide wire 10", which has been inserted into aorta 11 for advancing catheter 17 towards aortic valve 14 of Fig. 2, is as well inserted through residual opening 15 of aortic valve 14 of Fig. 2.

Hence, the same guide wire can be used for both procedures.

Further, in this embodiment, first shaping element 26 may function exactly following the scheme described for the first embodiment of catheter 17, wherein first shaping element 26 may serve either to straighten a pre-shaped catheter sleeve 18 or to bring a flexible catheter sleeve 18 into a helical or spiral conformation.

Fig. 6 shows catheter 17 according to a fourth embodiment of the present invention in cross section, whereby the plane of the cross section corresponds to plane A, as indicated in Fig. 2.

Catheter 17 comprises a catheter sleeve 18'" having, in this embodiment, four lumina. The first lumen 23 houses first guide wire 10, the second lumen 25 accommodates second guide wire 24, the third lumen 27 accommodates first shaping element 26, and a fourth lumen 29 houses a second shaping element 28.

The difference between this fourth embodiment and the first embodiment, shown in Fig. 3, is that in the fourth embodiment neither catheter sleeve 18'" nor guide wires 10 and 24 are directly involved in distal section 19 of Fig. 2 assuming a helical or spiral conformation or a straight shape.

In this embodiment, catheter sleeve 18 is flexible. Second shaping element 28 is adjusted to assuming a helical or spiral shape whereas first shaping element 26 has a straight form. Hence, when second shaping element 28 and first shaping element 26 are juxtaposed inside catheter sleeve 18'", catheter 17 has a straight form. When shaping element 26 is retracted from lumen 27, catheter 17 in distal section 19 of Fig. 2 assumes a helical or spiral conformation. When second shaping element 28 is as well retracted from lumen 29, catheter 17 again assumes a straight conformation.

Fig. 7 shows aorta 11 of Fig. 2, wherein distal section 19 of catheter 17 has assumed a helical conformation with a centring shaft 30. Second fenestration 22 is centred to longitudinal axis 16 of aorta 11, being exactly aligned with the optimal entry vector through residual opening 15 of aortic valve 14, the entry vector being marked by an arrow.

At this stage, the position of second fenestration 22 with respect to aortic valve 14 can be easily altered by the operator by twisting or pushing and pulling catheter 17.

Hence, second fenestration 22 can be brought into juxtaposition with residual opening 15 of aortic valve 14 even in cases, where residual opening 15 is offset from the centre of aortic valve 14.

When second fenestration 22 is brought into juxtaposition with residual opening 15, guide wire 24 (or respectively guide wire 10") is to be inserted along the optimal entry vector (arrow) into residual opening 15.

This situation is shown in Fig. 8.

Fig. 8 shows catheter 17 as in Fig. 7, wherein second guide wire 24 has been inserted into residual opening 15 of aortic valve 14.

As second guide wire 24 is now inserted into its final position within aortic valve 14, catheter 17 has to be retracted in order to allow the insertion of another catheter, for example a catheter comprising an endoluminal prosthesis for functionally replacing aortic valve 14.

For this purpose, catheter 17 is straightened following the schemes described in connection with the first to fourth embodiments (see description of Fig. 3 to 6).

After retraction of catheter 17, a second catheter is inserted into aorta 11 via guide wire 24 (or respectively guide wire 10").

This situation is shown in Fig. 9.

Fig. 9 shows aorta 11 as in Fig. 8, wherein a second catheter 31 is inserted into aorta 11 via guide wire 24.

Catheter 31 may be a catheter for directly replacing aortic valve 14, which means that catheter 31 may comprise an endoluminal prosthesis for the replacement of aortic valve 14, which endoluminal prosthesis is to be inserted into the residual opening and then deployed in order to press the leaflets of aortic valve 14 to aortic walls 12 and take over their function.

Alternatively, before replacement of aortic valve 14, it may also be necessary to replace guide wire 24 now present within residual opening 15 of aortic valve 14 by a guide wire of different characteristics, such as lower flexibility.

Such replacement of guide wire 24 can be accomplished using a simple two lumen catheter 31, which is advanced through the residual opening 15 of aortic valve 14 along second guide wire 24 and is then used to insert, through residual opening 15 of aortic valve 14, a different guide wire (not shown), whereupon second guide wire 24 and catheter 31 are retracted from aorta 11. Fig. 10 shows in partial sectional view a section of catheter 17 according to the second embodiment, shown as well in Fig. 4.

Catheter 17 here is shown at that point of the intervention, where it has been advanced towards aortic valve 14 of Fig. 2. When catheter 17 is further inserted into aorta 11, catheter sleeve 18' begins to extend beyond guide wire 10', serving in this connection as well a shaping element.

Alternatively, guide wire 10' may be retracted from catheter lumen 23'.

In either case, preformed catheter sleeve 18', no longer being kept straight by guide wire 10', begins to assume its spiral or helical shape.

This situation is shown in Fig. 11.

Fig. 11 shows the distal section of catheter 17 of Fig. 10, catheter sleeve 18' now being advanced beyond the end of guide wire 10'.

As catheter sleeve 18' is pre-shaped, it begins to adopt a spiral or helical shape where it is devoid of counter pressure exerted by guide wire 10'.

At first, distal end 21 of catheter 17 begins to form a j-shape, which then wiil gradually extend into a spiral or helical shape.

This situation is shown in Fig. 12.

Fig. 12 shows the section of catheter 17 of Fig. 11, catheter 17 now having assumed a spiral or helical conformation with a centring shaft 30. This configuration corresponds to the situation shown before in Fig. 7, where distal section 19 has assumed a helical shape and second fenestration 22 juxtaposes residual opening 15 of aortic valve 14.

Guide wire 10' is now retracted beyond distal section 19, second fenestration 22 being centred to the helix or spiral formed by catheter sleeve 18'.

At this stage, second guide wire 24 is inserted into catheter lumen 25. Second guide wire 24 can then exit catheter sleeve 18' through second fenestration 22.

This situation is shown in Fig. 13.

Fig. 13 shows the distal section of catheter 17 of Fig. 12, second guide wire 24 being inserted into catheter lumen 25 and exiting catheter sleeve 18' through second fenestration 22.

This configuration corresponds to the situation shown before in Fig. 8, where second guide wire 24 has been advanced through residual opening 15 of aortic valve 14.

As guide wire 24 now is in its final position, catheter 17 and first guide wire 10' need to be retracted from aorta 11. For this reason, catheter 17 needs to be straightened.

This situation is shown in Fig. 14.

Fig. 14 shows catheter 17 of Fig. 13, guide wire 10' being reinserted into section 19 of catheter 17.

By reinserting guide wire 10' into distal section 19, catheter sleeve 18' is again brought into straight form. In this connection, it is to be noted, that alternatively catheter sleeve 18' may be retracted in distal direction over guide wire 10'. This way being pulled away from aortic valve 14 and avoiding damages to aortic valve 14.

After straightening catheter 17, catheter 17 including as well guide wire 10', can be retracted from aorta 11.

During the process of retraction, guide wire 24, which is to rest in the residual opening 15 of aortic valve 14 as well as aorta 11, exits re-straightened catheter sleeve 18' through second fenestration 22.

According to a supplemental invention, a catheter is provided, which may serve for the improvement of visualizing the position and tilt of aortic valve 14 inside aorta 11 using X-Ray during an intervention.

Such visualization catheter is shown in Fig. 15.

Fig. 15 shows, in sectional side view, a catheter 32 according to the supplemental invention, wherein catheter 32 has assumed a helical conformation in direct proximity to aortic valve 14.

Dashed line B indicates the plane of the cross section shown in Fig. 16.

Visualization catheter 32 comprises a catheter sleeve 33 with a distal section 34 adjusted to at least temporarily assuming a helical or spiral confirmation. In this, catheter 32 corresponds to catheter 17, described hereinabove.

Further, in the region of distal section 34, visualization catheter 32, in addition to a first fenestration 36, comprises a number of openings 37, equally distributed around the circumference of the helix or spiral formed by distal section 34, openings 37 facing to the inside of distal section 34. When pushed against aortic valve 14, distal section 34 adjusts its position to the position and tilt of aortic valve 14, thereby making possible the direct visualization of position and tilt of aortic valve 14. In this connection, visualization can be achieved either by injecting into catheter 32 a radiopaque liquid, so that catheter 32 itself becomes radiopaque and can be visualized on X-ray, or, alternatively, radiopaque liquid may be injected into aorta 11 via the circumferentially distributed openings 37 and, for example, also first fenestration 36.

Hence, the radiopaque liquid is distributed in the aortic lumen very quickly and completely.

Visualization catheter 32, thus, enables easy determination of position and tilt of aortic valve 14.

Fig. 16 shows visualization catheter 32 in top view as seen in distal to proximal direction.

Visualization catheter 32, according to one embodiment, has a catheter sleeve 33 comprising three lumina. A lumen 38 accommodates a first guide wire 10, a lumen 39 is adjusted for guiding liquid, and a lumen 40 accommodates a shaping element 41.

Further embodiments of catheter 32, concerning the number of lumina and the function of the first guide wire 10 and first shaping element 26 correspond to the second and fourth embodiments of catheter 17, shown in Figs. 4 and 6.

Catheter 32 shows most of the features of catheter 17 according to anyone of embodiments 1, 2 and 4 shown in Figs. 3, 4 and 6. Accordingly, catheter sleeve 33 corresponds structurally and functionally to catheter sleeve 18, as described for embodiments 1 to 4 of catheter 17. The same holds true for shaping element 40, corresponding to shaping element 26, and for guide wire 10.

Such catheter can, accordingly, be brought into a helical conformation exactly following the scheme described already for embodiments 1 to 4 described in the previous figures.

Catheter 32 differs from catheter 17 in that its second lumen does not accommodate a second guide wire 24, but rather is adjusted for guiding a liquid. Further, catheter 32 does not comprise a second fenestration 22, but rather a number of openings 37, said openings 37 connecting to said lumen 39.

When injecting liquid into lumen 39, the liquid will exit catheter sleeve 33 through openings 37 and, for example, also through first fenestration 36, becoming distributed in aorta 11.

Fig. 17 shows, in partial sectional side view, a catheter 32' according to a second embodiment of the supplemental invention, wherein catheter 32' has assumed a helical conformation in direct proximity to aortic valve 14.

Visualization catheter 32' comprises a catheter sleeve 33' with a distal section 34' adjusted to at least temporarily assuming a helical or spiral confirmation.

Different from visualization catheter 32, shown in Figs. 15 and 16, visualization catheter 32' comprises a centring shaft 35', which is shorter than centring shaft 35 of catheter 32. As a consequence, visualization catheter 32', proximal to distal section 34', is offset from the centre of aorta 11.

For this reason, visualization catheter 32' does not interfere with the placement of another catheter (not shown) through the centre of aortic valve 14. Further, catheter 32' differs from catheter 32 in that its catheter sleeve 33' does not have openings 36 provided therein.

Moreover, instead of guiding a liquid, lumen 39 accommodates a number of solid radiopaque markers 42.

When pushed against aortic valve 14, distal section 34' adjusts its position to the position and tilt of aortic valve 14, thereby making possible the direct visualization of position and tilt of aortic valve 14. In this embodiment, visualization is achieved by the solid radiopaque markers 42 being accommodated in lumen 29 of Fig. 16. Radiopaque markers 42 form a more or less annular structure when distal section 34' has assumed its helical or spiral conformation and is pressed against aortic valve 14.

This annular structure makes possible visualizing of the position and tilt of aortic valve 14.

In addition, the radiopaque markers 42 are separated from each other by a broad gap 43 and narrow gaps 44.

The position of these gaps 43 and 44 is chosen such that the orientation of the front and aft sides of the annular structure with respect to the plane of X-Ray visualization can easily be determined.

For this reason, broad gap 43 is approximately 90° radian measure apart from narrow gaps 44.

In Fig. 17 aortic valve 14 is tilted with respect to the visualized plane such that its downstream side, facing away from the heart (not shown) is visible, is facing the viewer. Accordingly, an X-Ray image, corresponding to the view of Fig. 17, shows that broad gap 43 is positioned on the left side of the annular structure whereas narrow gaps 44 are present in the lower half of the annular structure. The operator hence knows that the lower half of the annular structure is facing in direction towards the viewer of the X-Ray image and that, correspondingly, the leaflets of aortic valve 14 in a lower position are closer to the viewer.

A different example is shown in Fig. 18.

Here, the orientation of the annular structure and as well the orientation of aortic valve 14 with respect to the visualized plane is reversed compared with the orientation of the example described in connection with Fig. 17.

Hence, in Fig. 18, the upstream side of aortic valve 14 is visible. In this case, the leaflets of aortic valve 14 in upper position are facing the viewer.

Owing to gaps 43 and 44 provided in between the radiopaque markers 42 accommodated in catheter 32', this orientation can be distinguished from the orientation shown in Fig. 17.

This is the case, because this time, while narrow gaps 44 are still present in the lower half of the annular structure, broad gap 43 is visible at the right side of the annular structure. Therefore, the operator can see that the lower half of the annular structure is facing away from the viewer of the X-Ray image. Therefore, the leaflets of aortic valve 14 in a upper position are closer to the viewer.

Hence, aortic valve 14 can be visualized such, that its position and tilt and also its orientation with respect to the visualized plane are easily determined by the operator.

Claims

1. Catheter (17) for insertion into a body lumen (11), the catheter (17) having a catheter sleeve (18) comprising a distal section (19) configured to at least temporarily assume an essentially helical or spiral shape, a first lumen (23) for accommodating a first guide wire (10), a second lumen (25) for accommodating a second guide wire (24), a third lumen (27) for accommodating a first shaping element (26), and a first fenestration (20) at the distal end (21) of the catheter (17), connecting to the fist, second and/or third lumen (23, 25, 27), wherein the catheter sleeve (18) comprises a second fenestration (22) provided proximal to the first fenestration (20), said distal section (19) being provided between said first fenestration (20) and said second fenestration (22), the second fenestration (22) connects to the first, second and/or third lumen (23, 25, 27), and the distal section (19) is configured to assume the essentially helical or spiral shape such that the second fenestration (22) is essentially centred to the body lumen (11) when said catheter (17) is inserted into the body lumen (11).

2. Catheter according to claim 1, characterized in that the first lumen (23) serves also as the third lumen (27) and the first guide wire (10) serves also as the first shaping element (26).

3. Catheter according to claim 1, characterized in that the first lumen (23) serves also as the second lumen (25) and the first guide wire (10) serves also as the second guide wire (24).

4. Catheter according to anyone of claims 1 to 3, characterized in that the first shaping element (26), when fully inserted into said third lumen (27), is adjusted to straightening the distal section (19) in longitudinal direction.

5. Catheter according to anyone of claims 1 to 4, characterized in that the distal section (19) of the catheter sleeve (18) is preformed for at least temporarily assuming an essentially helical or spiral shape.

6. Catheter according to anyone of claims 1 to 4, characterized in that it comprises a fourth lumen (29) for accommodating a second shaping element (28).

7. Catheter according to claim 6, characterized in that the second shaping element (28) is adjusted at its distal end to at least temporarily assuming an essentially helical or spiral shape.

8. Catheter according to anyone of claims 1 to 7, characterized in that the first shaping element (26) and/or the second shaping element (28) is comprised of shape-memory material.

9. Catheter according to anyone of claims 1 to 8, characterized in that it comprises a lumen (33), which can guide a liquid.

10. Catheter (17) for insertion into a body lumen (11), the catheter having a catheter sleeve (18) comprising a distal section (19) preformed for at least temporarily assuming an essentially helical or spiral shape, a first lumen (23) for accommodating a first guide wire (10), a second lumen (25) for accommodating a second guide wire (24), a third lumen (27) for accommodating a first shaping element (26), said shaping element (26), when fully inserted into said third lumen (27), being adjusted to straightening the distal section (19) in longitudinal direction, a first fenestration (20) at the distal end (21) of the catheter (17), connecting to the fist, second and/or third lumen (23, 25, 27), and a second fenestration (22) provided proximal to the first fenestration (20) said distal section (19) being provided between said first fenestration (20) and said second fenestration (22).

11. Catheter (17) for insertion into a body lumen (11), the catheter having a catheter sleeve (18") comprising a distal section (19) which is flexible in order to permit it to at least temporarily assume an essentially helical or spiral shape, a first lumen (23") for accommodating a first guide wire (10"), a second lumen (25) for accommodating a first shaping element (26), said shaping element (26) being adjusted at its distal end to at least temporarily assuming an essentially helical or spiral shape, a first fenestration (20) at the distal end (21) of the catheter (17), connecting to the fist and/or second lumen (23", 25), and a second fenestration (22) provided proximal to the first fenestration (20) said distal section (19) being provided between said first fenestration (20) and said second fenestration (22).

12. Method of advancing a guide wire (10) through a constriction of a body lumen (11), preferably an aortic valve (14), using a catheter (17) according to anyone of claims 1 to 9, said method comprising the steps of a) advancing the first guide wire (10) towards the constriction (14), b) advancing the catheter (17) towards the constriction (14) via the first guide wire (10), c) allowing the distal section (19) to assume an essentially helical or spiral shape, d) advancing the second guide wire (24) so that it exits the catheter sleeve (18) through the second fenestration (22), e) advancing the second guide wire (24) through the constriction (14), f) straightening and/or relaxing the catheter sleeve (18), and g) retracting the catheter (17) from the body lumen (11).

13. Method of advancing a guide wire (10) through a constriction of a body lumen (11), preferably an aortic valve (14), using a catheter (17) according to claim 10, said method comprising the steps of a) advancing the first guide wire (10) towards the constriction (14), b) advancing the catheter (17) towards the constriction (14) via the first guide wire (10), allowing the distal section (19) to assume an essentially helical or spiral shape by advancing the catheter sleeve (18) beyond the distal end of the first guide wire (10), c) advancing the second guide wire (24) so that it exits the catheter sleeve (18) through the second fenestration (22), d) advancing the second guide wire (24) through the constriction (14), e) retracting the catheter sleeve (18) over the first shaping element (26) in order to straighten the distal section (19), and f) retracting the catheter (17) from the body lumen (11).

14. Method of advancing a guide wire (10") through a constriction of a body lumen (11), preferably an aortic valve (14), using a catheter (17) according to claim 11, said method comprising the steps of a) advancing the first guide wire (10") towards the constriction (14), b) advancing the catheter (17) towards the constriction (14) via the first guide wire (10"), allowing the distal section (19) to assume an essentially helical or spiral shape by advancing the catheter sleeve (18") beyond the first guide wire (10"), such that the tip of the first guide wire (10") comes to lie proximal to the second fenestration (22), c) advancing the first guide wire (24) so that it exits the catheter sleeve (18") through the second fenestration (22), d) retracting the shaping element (28) so that the distal section (19) is relaxed, and e) retracting the catheter (17) from the body lumen (11).

15. Catheter (32) for visualizing the spatial orientation of a constriction (14) inside a body lumen (11), the catheter (32) having a catheter sleeve (33) comprising a distal section (34) configured to at least temporarily assume an essentially helical or spiral shape, a first lumen (38) for accommodating a first guide wire (10), a second lumen (40) for accommodating a first shaping element (41), a third lumen (39) for accommodating a radiopaque material, and a first fenestration (36) at the distal end of the catheter, connecting to at least the fist lumen (38).

16. Catheter (32) according to claim 15, characterized in that the third lumen (39) is adjusted for receiving a liquid and that the radiopaque material is a radiopaque liquid.

17. Catheter (32) according to claim 16, characterized in the catheter sleeve (33) comprises, in the region of the distal section (34), two or more openings (37) connecting to the third lumen (39).

18. Catheter (32) according to anyone of claims 15 to 17, characterized in that the third lumen (39) accommodates at least one solid radiopaque marker (42).

19. Catheter (32) according to anyone of claims 15 to 18, characterized in that its distal section (34) is configured such that, when said distal section (34) has assumed its essentially helical or spiral shape, said catheter sleeve (33), proximal to distal section (34), is offset from the centre of body lumen (11).

20. Method of a visualizing the spatial orientation of a constriction (14) inside a body lumen, using a catheter (32) according to anyone of claims 15 to 19, said method comprising the steps of a) advancing the first guide wire (10) through a body lumen (11) towards the constriction (14), b) advancing the catheter (32) towards the constriction (14) via the first guide wire (10), c) allowing the distal section (34) to assume an essentially helical or spiral shape, d) determining, using an X-Ray device, the spatial orientation of the constriction (14), e) straightening and/or relaxing the catheter sleeve (33), and f) retracting the catheter (32) from the body lumen (11).

21. Method according to claim 20, characterized in that after step c) a radiopaque liquid is injected through the third lumen (39) into the body lumen (11).

22. Kit, comprising a catheter (17) according to anyone of claims 1 to 11 and a catheter (32) according to anyone of claims 15 to 19.