WO2013008204A2

WO2013008204A2 - System for tissue marking and treatment

Info

Publication number: WO2013008204A2
Application number: PCT/IB2012/053579
Authority: WO
Inventors: Vitali Verin; Bandar HAKIM
Original assignee: Maestroheart Sa
Priority date: 2011-07-12
Filing date: 2012-07-12
Publication date: 2013-01-17
Also published as: WO2013008204A9; WO2013008204A3

Abstract

The system for marking the surface of tissue, for example in the body of a patient, comprises a delivery means with a head for treating a determined zone and a marking means for delivering a marker, wherein said delivery and marking means are in close proximity such that the marker is delivered substantially to the zone compressed by the head of the delivery means.

Description

SYSTEM FOR TISSUE MARKING AND TREATMENT

Cross-reference to related application The present application claims the benefit of the priority of the Swiss patent application Number 01 166/1 1 , filed on July 12, 2011 in the name of Maestroheart S.A., the entire disclosure of which is incorporated herein by reference.

Field of the invention

The present invention concerns a tissue marker and a delivery system used for example for marking soft tissue in a body (human or animal) in particular the surfaces of hollow organs (internal and external) before during or after a treatment, for example an ablation.

More specifically, the present invention concerns inter alia a tissue marker that can be used with medical devices or apparatuses for ablating tissues point by point and/or along continuous lines for example in the heart chambers for treating different arrhythmias, in renal arteries for renal denervation, or other places of the human/animal body.

The present invention also concerns a method for delivering markers to the surface of tissue before, during or after a treatment of said tissue has been carried out. Typically, a treatment envisaged is ablation of tissue but other treatments are of course possible.

Background of the invention and prior art

Abnormal heart rhythms are generally referred to as cardiac arrhythmias and with an abnormally rapid rhythm called tachycardia. Atrial fibrillation is an abnormal irregular rhythm of the heart caused by abnormal electrical discharges within the two upper chambers of the heart called atria. Atrial fibrillation reduces the ability of the atria to pump blood into the lower chambers of the heart (the ventricles) and usually causes l the heart to beat very rapidly and may induce complications that include heart failure and stroke.

While medications have been used to treat arrhythmias and prevent recurrence of atrial fibrillation, they are not always effective and may induce undesirable or intolerable sometimes life threatening side effects. Furthermore they do not cure the underlying causes. Implantable devices have also been used but they only correct the arrhythmia after it occurs and do not help to prevent it. Surgical and invasive catheterisation approaches in contrast are promising and give very good results as they treat the problem by ablating the portion of the heart tissue that causes electrical trouble inducing arrhythmia.

One commonly used technique for performing ablation is known as radiofrequency (RF) catheter ablation. This technique uses an ablation electrode mounted at the distal end of a catheter that is introduced by natural passageways in the target heart chamber and then manipulated by a surgeon thanks to a handle at the proximal end of the catheter acting on a steering mechanism. This allows displacement of the distal end of the catheter so as to have the ablation electrode lying at the exact position determined by the fluoroscopy and/or heart mapping technique. Once the ablation electrode is in contact with the pre-determined area, RF energy is applied to ablate the cardiac tissue. By successfully causing a lesion on the pre-determined portion of the cardiac tissues, the abnormal electrical pathways responsible for the arrhythmia are eliminated.

To perform ablation a physician (usually electrophysiologist) manipulates the ablation catheter inside the heart under fluoroscopy. Under fluoroscopy guidance the ablation catheter is positioned at certain locations inside the heart chamber. The RF energy is then delivered to heat the tissue at the wall of the organ. To treat certain arrhythmias multiple ablation points at multiple locations need to be delivered. Unfortunately the ablated tissue is not visible under fluoroscopy and the physician has no means to track the points, which were ablated. To alleviate somewhat this problem, very often a cardiac 3D mapping is firstly performed in order to create a 3D representation of the cardiac chambers anatomy to locate aberrant electrical pathways within the heart as well as to keep in memory the 3D coordinates of ablation points. This mapping is done before performing the ablation of some portions of the inner wall of the atria and ventricles. Various methods and devices have been disclosed and are commonly used to establish precise mapping of the heart. Once this mapping is done, the clinician will refer to this heart map, which indicates the points and lines along which ablation is to be performed and keep in memory the points at which ablation energy was delivered. Importantly the 3D map of the cardiac chamber as well as the tagged ablation points are mostly representing virtual anatomy and the correlation between this 3D representation and real anatomy is not accurate. Therefore this 3D map and 3D position of the ablation points on this map lack precision. In addition those maps are even less accurate and even much less useful when a second procedure is to be performed some weeks or months after the first procedure.

The absence of real time visualisation of the atrial wall during the intervention hampers the generation of precise continuous ablation lines. The gaps between ablation points result in a lack of treatment efficacy and may cause atrial flutter. It would be therefore very useful to permanently mark the surface or locations of the heart wall to be ablated or the points that have been treated, i.e. where ablation energy has been applied. Furthermore, starting from the specific application of ablation, the concept could be extended to the permanent marking of treatment areas/points either before, directly during treatment or subsequently, the aim being to permanently keep a visible track of the treated areas or points or points to be treated.

The need to mark ablated tissue is not only limited to the treatment of cardiac arrhythmias but also to other areas where ablative energy is being delivered. Such a recent application of ablative energy is renal artery denervation (http://www.ardian.com/ous/index.shtml) where to make ablated tissue visible is also of major importance. Another known problem relates to the determination of the correct level of energy to deliver to the ablation tip so as to precisely control the ablation lesion depth. When the distal end of the catheter is not correctly positioned or when the ablation electrode is not perpendicular to the cardiac tissue, energy applied may be either too low, in that case the lesion is ineffective, or too high which may lead in rare cases to atrial wall perforation, oesophageal burns and atrial-oesophageal fistula formation. This complication, although rare, is extremely devastating and fatal in more than half of the reported cases. The use of a temperature sensor at the tip of the catheter in the vicinity of the ablating electrode does not help to solve this problem as it does not provide an accurate measure of the tissue temperature because the measure is mostly influenced by the heating of the ablation electrode and its cooling by the irrigation liquid when RF energy is applied. It would therefore be desirable to provide a technology allowing the creation of reproducible predictable lesions.

Ablation devices have been disclosed in PCT applications WO 2008/010039 and WO 20 0/007600 and these documents are incorporated by reference in their entirety in the present application for the disclosure of such a device.

Other prior art publications are the following documents: US 7,322,360, US 6,951 ,564, EP 0 873 091 , US 6,173,715, US 7,556,647, US 7,569,065, US D602,590, US 7,625,397, US 7,819,820, US 7,846,108, EP 0 481 685, WO 2005/094727, US 2008/0033286, US 7,862,602, US 5,980,514, US 5,902,310, US 5,122,136 and EP 1 249 207.

As mentioned previously, one of the problems an electrophysiologist is confronted with in such ablation procedures is to keep track of the ablation points or regions in a given patient. Since ablation is carried out with an imaging system and because the ablated tissue cannot be differentiated from non-ablated tissue with available imaging systems, it is difficult, if not impossible, to find the ablation points or lines that have just been applied as well as after a certain time in order, for example to carry out a subsequent ablation procedure. By extension, on a more general level, a problem physicians are confronted with is the permanent marking of areas/points to be treated or having been treated such that the marking remains visible over time, either for immediate use/consideration (for example for real-time tracking) or for a future use/consideration. Summary of the invention

It is therefore an aim of the present invention to propose a simple and reliable tissue marking system.

It is a purpose of this invention to propose a tissue marking system, which is able to mark the internal and external surface of hollow organs such as the heart, renal artery or other organ before, during or after a treatment of the organ. More specifically, an aim of the present invention is to propose a marking system that may be used with an ablation catheter to mark the ablated tissue in order to improve the overall results of the ablation procedure.

Accordingly, the present invention concerns a marking element that is attachable or self-attachable to the surface of the hollow organ wall tissue being marked, for example self-deformable, preferably avoiding a specific action from the user to create such attachment, for example by deformation. The attachment to the surface of the wall could be done using mechanical means, shape memory alloy deformation, gluing, magnetic attraction, dry adhesion, etc. as will be understood from the following description of different embodiments.

As examples, one may mention here as attachment means or principles: hooking, puncturing, nailing, screwing, stapling, harpooning, Velcro(R)-like attaching, pinching, gluing as possibilities. Additionally, one may envisage other physical effects for the attachment of the marker, for example Van der Waals forces (like the feet of a gecko). Any mechanism or combination of mechanisms may be used.

For the sake of clarity, it is noted here that in the rest of the present application, the notion of "marking element" and "marker" will be used indifferently. Likewise, the "catheter head" will mean in the rest of the present application a part of the catheter entering in contact with tissue during marker delivery and is not limited to "catheter tip" or "tip electrode". In an embodiment, the marking element is made of a shape memory material, for example an alloy (such as Nitinol), and its deformation to attach to tissue is created by heat. Of course, other equivalent means are possible which have the same result. Indeed, in order to facilitate delivery of the marker to tissue surface avoiding complex mechanism of marker release from a delivery system, heat activated materials (such as shape memory alloys e.g. Nitinol) are of particular interest. In such devices the marker changes its geometrical shape under the influence of heat generated during the process of tissue ablation. This shape change allows the marker to attach to the tissue surface. Preferably, in a same move, the marker disconnects from the delivery system. In this way, the tissue heating (for example for ablation), tissue marker delivery and marker release from the delivery system is done at the same time and no additional mechanisms are needed. Importantly, the marker shape transformation in this case is preferably taking place at temperatures higher than body temperature and surely higher than 38°C.

This embodiment using heat activated materials is of particular interest when the marking element is used in combination with an ablation catheter applying heat to tissue, as will be apparent from the following detailed description. As mentioned above, typical catheters of this type are disclosed in PCT applications WO 2008/010039 and WO 2010/007600 for example. Such catheter types are of course not exclusive and other catheter types may be used, dedicated or not. For example, the catheter may not be an ablation catheter but still possesses a heating capability to deliver the marker where desired, thereby using the shape memory properties of the marker.

In an embodiment, the marking element has the shape of a star with several arms (for example six). The marker may have another shape as well suitable for the intended use, for example needle, harpoon, screw, staple, clip, etc. (see for example fig. 23 to 33).

In an embodiment, the marking element is used as a single element and in other embodiments; marking elements may be available as a set of several elements (e.g. more than one). In an embodiment, the marking element is placed on a delivery catheter, for example an ablation catheter, and preferably at the tip of said catheter. In another embodiment, the marking element is placed inside a delivery catheter, preferably near the tip of said catheter. In an embodiment, the marking element is next to the delivery catheter.

The aim of the present invention being to deliver a marker at the treatment location or at least at a position close or very close to the treatment location. In an embodiment, the marking element may comprise a magnetic part which cooperates with a corresponding magnetic part on the delivery catheter for holding the making element on the catheter. Preferably, in this case, the magnetic part of the catheter is movable in order to release the marking element. Other equivalent means are of course possible in the frame of the present invention.

In an embodiment, the invention comprises system for marking the surface of tissue, for example a hollow organ in the body of a patient, wherein said system comprises a catheter with a head and a marking means for delivering at least one marker, wherein said head and said marking means are in close proximity such that the marker is delivered substantially to the zone of tissue compression by said catheter head.

In an embodiment the catheter is an ablation catheter with an ablation head. In an embodiment the marker is self attachable to said tissue. In an embodiment the marker is self-deformable.

In an embodiment the marker is self-attachable or self-deformable by application of heat.

In an embodiment said marker has the shape of a staple, a star, a nail, a screw, a harpoon, a coil, a clip, or a needle or another similar shape. In an embodiment said marker is delivered to tissue using mechanical energy, hydraulic energy, shock waives or explosion energy.

In an embodiment said marker is made of a shape-memory alloy.

In an embodiment said marker is serving for delivering ablation energy.

In an embodiment said marker is RF energy delivering electrode. In an embodiment said marker is delivering energy on tissue surface and/or intramurally.

In an embodiment the catheter or the marking means carry a plurality of markers. In an embodiment said markers are interconnected allowing their withdrawal from the catheter or the marking means before the marker in contact with tissue is completely released.

In an embodiment the marker(s) is (are) placed on the catheter.

In an embodiment said marker at least comprises a magnetic part and the catheter comprises a mobile magnetic part for temporary coupling with the magnetic part of the marker. In an embodiment, there is method for marking the surface of tissue, for example in the body of a patient, whereby said marking is carried out before, during or after a treatment, such that the parts to be treated or the treated parts are marked and carry a durable marking. In an embodiment the marking is realized by application of heat such as to provoke the deformation of a marker to be applied.

In an embodiment successive treatment and marking are carried out. In an embodiment the treatment is ablation of tissue.

The marking element of the present invention may be used in any marking process where it may be needed to keep trace of specific positions on the tissue. As mentioned above, this may be for example ablation points in the human body. This application is not exclusive and others may be envisaged in the frame of the present invention for example for imaging purposes and other treatments. Accordingly, the used delivery device may be any catheter, and not limited to ablation catheters. Several embodiments are now described in the following specification.

Detailed description of the invention

The present invention will be better understood by the detailed description of several embodiments together with the attached figures which show:

Figures 1 to 3 illustrate an embodiment of the invention;

Figures 4 and 5 illustrate a further embodiment of the present invention;

Figures 6 to 8 illustrate a further embodiment of the present invention; Figures 9 to 1 1 illustrate a further embodiment of the present invention; Figures 12 to 14 illustrate a further embodiment of the present invention; Figures 15 to 17 illustrate another embodiment of the present invention; Figures 18 and 19 illustrate another embodiment of the present invention;

Figures 20 to 22 illustrate another embodiment of the present invention; Figures 23 to 33 illustrate different possibilities to realize a marker and Figure 34 to 53 illustrate further embodiments of a system according to the present invention.

In the following description, for the sake of clarity and simplicity, similar or identical parts and elements will be identified by the same reference numbers in principle. In some instances, for the sake of clarity of the description of an embodiment, other references will be used but the terminology remains identical.

An embodiment is now described with reference to figures 1 to 3. In this embodiment, the marking element or marker 1 has the general shape of a star or spider with arms or legs 2. For example, it may have six arms but can also have less or more arms. In figure 1 , the marker is mounted on the tip 3 of a delivery means 4. This delivery means may typically, but not exclusively, be a catheter, such as an ablation catheter. Reference 5 denominates the object on which the maker will be applied, such object being typically a tissue (i.e. a wall of a hollow organ in any part of the human body).

On figure 1 , the marker 1 is pressed against the tissue 5 by the delivery means 3-4.

Preferably, in this embodiment and as illustrated in figures 1 and 3, the marker 1 is self attached to the tip 3, for example by pressure exerted by arms 2 against tip 3. The interest of this principle will be explained later in the present description.

On figure 2, the maker 1 is being attached to the tissue using the self deformation properties of the marker 1 . More specifically, the arms 2 of the marker 1 have now "turned around" and have penetrated into tissue 5 by a gripping effect thus detaching the marker 1 from the tip 3 of the delivery device 4. This is done by heating the tip 3 of the delivery means 4, typically this could be an ablation catheter 4 that effectively applies heat to tissue at its tip electrode 3 by delivering the RF energy. As a consequence, a marker 1 is delivered at the exact locations at which heat is applied in an ablation procedure, thus marking the effective ablation point. The ablation catheter 4 could preferably have a force sensor at its tip 3 helping to implant the marker by indicating the contact force between the tip and the tissue during marker implantation. Advantageously, the marker is made from a shape memory material (for example a metallic alloy such as Nitinol) and heat and cold formed in a way that the desired effect takes place. Figure 2A illustrates a variant in which the tip 3' of the delivery catheter 4 comprises grooves 2" which correspond to the arms 2 of the marker. Accordingly, in this configuration, the marker 1 is flush with the surface of the catheter. The marker may be bent inside the grooves for a more efficient hold to the delivery means. Figure 3 illustrates an application example of the marker 1 in case of a cardiac procedure. The delivery means 4 is here an ablation catheter intended to deliver energy at its tip in order to ablate parts of the tissue, for example in a treatment against atrial fibrillation as exposed at the beginning of the present application and in prior art publications WO 2008/010039 and WO 2010/007600 for example. In such case, the ablation catheter 4 comprises a tip 3 which is able to heat the tissue against which it is applied, by RF energy or another similar method. As illustrated in figure 3, a first marker has already been delivered and placed on the tissue (this may have been done just before the new application or several hours/days/years before) and the delivery means 4 is in the process of applying a new marker 1 on the tissue 5. This new delivery may be done in accordance with the principles exposed above.

In the embodiment illustrated in figures 4 and 5, the system comprises a delivery means 4, for example an ablation catheter, with a tip electrode 3. The markers 1 have the shape of a star and are placed in matter of a sheet 6, for example a plastic sheet. This has the advantage over the previous embodiment of putting several markers at disposal for application to the tissue, rather than a single one on the delivery means. The sheet 6 is held by appropriate means 7, 8 allowing a precise placement of the marker against the tissue. In order to free a given marker, the tip 3 is for example put in contact with the opposite surface of the sheet 6 and then heated (for example by delivering the RF energy) which allows the marker to be freed from the sheet 6 and grip to the tissue, as explained with reference to figures 1 to 3 and in application of the principles of the present invention. This is illustrated in figure 5 where one marker is attached to the tissue 5 and the next marker 1 will be attached. A further embodiment is illustrated in figures 6 to 7. In this embodiment (see figure 8), the system is used for creating continuous linear ablation lines on the atrial wall. This embodiment thus comprises a delivery means, for example an ablation catheter 4 with a tip 3, in a gliding fit within a flexible catheter 6 containing the markers 1 integrated in its wall, the marked references 1 ' in figure 7 having been applied to the tissue 5, for example at an ablation point.

In the embodiment illustrated in figure 8, the ablation catheter 4 is coupled magnetically with another catheter 9-10 used as a guiding catheter, the ablation catheter being the guided catheter. This principle of coupled and guiding/guided catheter is explained in detail in applications WO 2008/0 0039 and WO 2010/007600 cited here above and incorporated by reference herein. Accordingly, like in previous embodiment, the marker maybe integrated in the wall of a sheath, which covers in gliding fit, the delivery means 3, 4 and then applied at the ablation points in a precise and simple manner. The marker could also be placed directly on the head 3 of the catheter 4.

In figures 9-1 1 another embodiment of the invention is illustrated. In this embodiment, one uses magnetic means to temporarily attach the marker 1 to the delivery means 4. More specifically, each marker comprises a magnetic part 1 1 , which is used for coupling with a corresponding magnetic part 12 of the delivery means, for example a catheter 4 with a tip 3. Preferably, the magnetic part 12 is placed at the distal end of the catheter 4 for ensuring a best coupling of the marker 1 and its proper positioning at the distal end. Once at the proper position on the tissue, the energy activation takes place and the marker attaches to the tissue in accordance with the teaching of the present application.

In order then to stop the coupling, or at least reduce it, the magnetic part 12 is attached to an inner guiding member 13 which allows an axial movement of the magnetic part 12. As illustrated in figure 10, the magnetic part 12 is moved away from the marker 1 to allow decoupling of both. Figure 1 1 illustrates the application of this embodiment in a human body (left atrium). Importantly, if a repeat procedure is to be done some weeks or months after the initial ablation and marker implantation procedure, the markers may easily be found by an ablation catheter having a magnet on its head and the energy could be delivered for the second time to the same marker. In figures 12 to 14, a further embodiment of the invention is illustrated. This embodiment is specific in that the tip 3 is ball-shaped and also the marker 1 has a shape that conforms to the one of the tip. This allows a better fixation of the marker 1 on the tip 3 with the arms 2 before delivery, said arms being preshaped as illustrated. Typically, while previously described configurations of markers 1 may be directly mounted on existing catheter with no adaptation needed, this embodiment requires a specific tip shape. Once deployed, the marker may take several shapes, as illustrated in figure 13 and 14. These shapes may be predetermined for example by the tissue, or the application location, or even the material used for the marker, or its size etc... In this and in other embodiments, the catheter head 3 could have irrigation channels well known in the art allowing for cooling of the ablation electrode and tissue surface. In case of irrigated catheter ablation and shape memory marker delivery, in order to allow a temperature rise on the marker leading to its attachment to the tissue surface, the irrigation should preferably be switched off during marker delivery and switched on should the ablation energy delivery be continued.

Figures 15 to 17 show another embodiment of the invention. In this embodiment, the marker 1 has arms that have different reactions to heat, i.e. they deploy at different temperatures as illustrated specifically in figure 16. Accordingly, in figure 15, the marker 1 is attached to the tip of the delivery means 4, for example a catheter heat is then applied to the tip 3 and a first set of arms 2" deploy and penetrate the tissue 5, the marker still being attached to the tip 3. For example, this temperature may be about 45°C. This first phase of tissue heating begins creating a lesion. Then, the temperature is increased and the second set of arms 2 then deploy in the tissue 5 when a second temperature is reached, for example 55°C, thus releasing the marker 1 . During this second phase of tissue heating the lesion size is increased and transmurality is possibly reached. Of course, other temperatures may be envisaged in the frame of the present invention. Figures 18 and 19 illustrate an embodiment of the present invention where a deflectable carrier is used to allow orientation of the marker in a way that it is parallel to the surface of the tissue independently of the angle between this surface and the catheter. More specifically, on the tip 3 of the delivery means 4, a movable carrier 14 is mounted which may move and rotate on the tip 3, thus allowing an orientation of the marker 1 to be deployed parallel relative to tissue surface. In this way, the marker 1 is oriented in the most optimal position with respect to tissue 5 surface during treatment (i.e. ablation) and release. Figure 18 shows the marker 1 before deployment and figure 19 after deployment.

Figures 20 to 22 illustrate another embodiment of the present invention using the principle of the present invention but where the marker has a different shape than in preceding embodiments. In this embodiment, the marker 20 has the general shape of a needle and is placed or integrated in the delivery means 21 , for example in a channel of said means 21. The channel 22 extends through the tip 23 and through the entire catheter length to allow delivery of the marker 20 at the distal end of the delivery means 21 as illustrated in figure 21 . More specifically, the marker 20 has a tip that separates into two parts 24, 25 under the influence of heat (according to the principles described herein with the use of shape memory alloys and materials) or mechanical means (utilizing super elastic alloy that deploy when released from the delivery channel). The marker can also take a harpoon-like shape (35) or any other suitable shape under the influence of heat. The deployment takes place in the tissue, once the marker 20 has been inserted in the tissue 5 in order to maintain the marker safely in position. Figure 22 illustrates the application of such marker in the human body using a catheter as delivery means 21. In a variant (illustrated in figure 20) one may add a joint 20' between the markers 20. Preferably, this joint 20' will dissolve when the marker 20 is applied.

The interest of the marker according to this embodiment is that the catheter (delivery means 21 ) may contain several markers 20 in the channel thus making the successive application of several markers more easy than with previous constructions carrying a single marker as described above. Typically, when making a line of several ablation points, it is useful to be able to apply successive markers at the successive effective ablation points. The markers 20 should of course be displaceable in the delivery means 21 by appropriate means, such as mechanical means (piston, pusher, screw, shock wave, hydraulic pressure, explosion or other means).

Figures 23 to 33 illustrate different embodiments of the marker that may be used in the present invention, each time in a configuration before application (at the top of each figure) and a configuration where it has been applied to the surface of the tissue 5. For example in figure 23, the marker 30 has a rounded shape before application and the general shape of a staple after application to the surface of the tissue.

In figure 24, the marker 31 has an elongated shape before application and a rounded shape after.

In figure 25, the marker 32 has the shape of a nail, and once applied parts 33, 34 of the nail separate to ensure a better attachment to the surface of the tissue 5.

Typically, in the embodiments of figures 23-25, the activation of the marker (to attain its deformed position) is done by heating, i.e. the markers are made in a shape memory alloy. In a variant, the marker 32 may comprise a radio opaque material part 32' as illustrated.

In figure 26, another marker embodiment is illustrated; in this case the marker 35 has an arrow (or harpoon) shaped end 36 which maintains the marker mechanically in the tissue 5. The arrow end 36 could be permanently deployed or only deploy by external activation for example heat activation if one uses shape memory alloys according to one of the teachings of the present invention. In a variant, the marker 35 may comprise a radio opaque material part 35' as illustrated. In further embodiments the mechanical principles of marker to tissue attachment are illustrated. The markers could be delivered to tissue using mechanical energy, hydraulic, shock waves, explosion or other suitable energy. In figure 27, the marker 37 has screw like end 38 to screw into the tissue and maintain the marker 37 in position. In a variant, the marker 37 may comprise a radio opaque material part 37' as illustrated. In figure 28, the marker 38 may be a simpler embodiment such as a nail. In a variant, the marker 38 may comprise a radio opaque material part 38' as illustrated.

In figure 29, the maker 39 may have the shape of a coil that is screwed in the tissue. It may be possible to use a shape memory alloy in this embodiment such that the marker shrinks once applied to improve its fixation to the tissue 5.

In figure 30, the marker 40 of this embodiment uses glue 41 that may be heat activated or not, as desired, once the marker 40 has been applied to the surface of tissue 5. Of course, the use of glue is not limited to this embodiment and it may be used in other embodiments. In a variant, the marker 40 may comprise a radio opaque material part 40' as illustrated.

In figure 31 , a Velcro(R) like fixation 43 of the marker 42 is illustrated. In a variant, the marker 42 may comprise a radio opaque material part 42' as illustrated.

In figure 32, a further embodiment is illustrated where the marker 44 is fixed by Van der Waals forces, using thin hair-like elements 45 similar to those of the gecko feet for example. In a variant, the marker 44 may comprise a radio opaque material part 44' as illustrated.

In figure 33, the marker 46 has the shape of a support with thin needles 47, The support is deformed when applied to the surface of tissue and by this deformation is maintained in position on the surface of the tissue 5. The deformation may be obtained mechanically or with a shape memory material, for example a metal that is heat activated or not.

Other embodiments of systems according to the present invention are illustrated in figures 34 to 44 and are described in more detail hereunder. In figures 34 and 35, an embodiment is shown wherein markers 50 are carried in a channel or lumen 51 of the delivery means 52, for example a catheter. Typically (as described previously in the present application), the catheter 52 has a distal tip 53 for treatment, for example heating of the tissue in the case of an ablation catheter. The advantage of this embodiment is the fact that the catheter may contain several markers so the delivery of successive markers is made easy. This can be needed for example when one wishes to form an ablation line, or other successive treatment with the same catheter without (preferably at least) removing the catheter. Accordingly, the markers 50 may be delivered successively at the distal tip 53 of the catheter 52, the delivery being effectuated by specific means in the catheter 52 (for example a pusher). Figure 35 illustrates more specifically a marker 50 having been delivered and the catheter 52 is ready to deliver a next marker 50. Of course, the number of markers 50 is not limited to two and several, i.e. more than two (as desired and appropriately designed) may be present as well. Any type of markers described in this application (23 to 33) but not limited to it, could be delivered in this manner.

In a variant (illustrated in figures 34 and 35) one may add a joint 50' between the markers 50. Preferably, this joint 50' will dissolve when the marker 50 is applied to allow separation, e.g. by electrolysis.

In figure 36, the system is similar to the one of figures 34, 35 with identical references and the difference resides in the shape of the markers 54 which are "harpoon- shaped". Other markers such as nail, needle, screw, etc. may also be delivered using the same principle. In a variant, one may add a joint 54" between the markers 54. Preferably, this joint 54" will dissolve when the marker 54 is applied to allow separation, e.g. by electrolysis.

In figure 37, the markers 55 have another shape where they are interconnected. Such a shape would for example facilitate their extraction from the delivery means 52 before the distal marker is completely disconnected from the next proximal marker once applied to the surface of tissue 5. Again different types of markers described in this application (23 to 33) could be designed and delivered using this principle. In these figures (as in figures 20-22), the channel 51 is illustrated centrally located in the delivery means (along the axis of the catheter 52) but of course it may also be laterally offset with respect to this axis as well, the aim being as in other embodiments to deliver the markers in proximity to the treatment area or zone of the tissue 5 compressed by the catheter head, see fig 40, 41

Figures 38 and 39 illustrate another embodiment wherein the markers have the shape of a coil 59. The coils 59 could have their distal tip sharp facilitating penetration into tissue. More specifically, the delivery means 56 (for example a catheter) with its distal tip 57 is covered by a sheath 58 which can be used to guide the marker 59 which is coil shaped for its penetration into tissue 5 (as illustrated in figure 39). The sheath 58 could be in sliding fit with the catheter 56. The tip 57 could be an ablation energy delivery head e.g. RF ablation electrode. In a variant (illustrated in figure 38) one may add a joint 59' between the markers 59. Preferably, this joint 59' will dissolve when the marker 59 is applied to allow separation. The connection between the coils could also be done in a way shown in fig 37. Likewise the coils 59 could be interconnected to allow withdrawal and release by screwing.

Figures 40 and 41 illustrate another embodiment in which the markers 60 are delivered from a channel 61 that is on the side of the delivery means 62 and its tip 63. The markers can be of any suitable shape and the markers 60 illustrated in figures 40 and 41 are only given as an example of a possible realization.

Figures 42 to 44 illustrate another example of means used to maintain a marker 65 on its delivery means. For example, such maintaining means may comprise a wire 66 temporarily attached to the marker 65. The wire 66 will extend in the delivery means (for example a catheter 67 with a tip 68) and be used to maintain the marker 65 on the tip 68. Once the marker 65 has been applied to the tissue 5 surface and attached to said surface (see figure 43), the wire may be detached from the marker 65. This operation may be done by the application of heat, when attaching the marker 65 to the tissue. Accordingly, the distal end of the wire 66 may be soldered to the marker 65, the heat or electrolysis (see US 5,122,136) being sufficient to remove the attachment of the wire 66 to the marker 65.This situation is illustrated in figure 44 where the delivery means 67 and the marker are separated from each other. Figure 44A illustrates a variant whereby the catheter 67 has a channel 67' in which the wire 66 extends and holds the marker 65 via a joint 66'. As mentioned above, this joint 66' will dissolve to free the applied marker 65.

Figure 45 illustrate the use of the system according to the present invention in a renal application, for example for marking ablation points or lines.

Figure 46 illustrates another use of the system according to the present invention in combination with the catheters of WO 2008/010039 and WO 2010/007600 (cited above) which are incorporated by reference herein, with a guided (ablation) marking catheter 4 and a guiding catheter 70.

Figures 47 to 49 illustrate an embodiment of the invention where the delivery means 71 -73 used to apply the marker 74 are pliers or a forceps with jaws 72/73 with hold a part 75 of the marker 74. For example by application of heat through the delivery means 71 -73, the marker will deform in accordance with the principle taught by the present invention and grip the surface of tissue 5, as illustrated in figure 48 and the delivery means may then be removed (figure 49).

Figure 50 to 52 illustrate a further embodiment of the invention. These figures specifically show a marking device 80 with a delivery means 4 and a tip 3 with several markers 81 that are fixed to said tip 3 of the device. Once a marker 81 is deployed and is properly attached to tissue 5 in accordance with the principle of the present invention, the marking device 80 can then be removed. If the marker 81 is not properly fixed to the tissue 5, it will remain attached to the tip 3 marking device 80 and can be retracted with removal of the device 80. In order to be held on the tip 3, the markers 81 may by mounted on a support 82 which may be in the shape of a wire or another equivalent element which may conform with the shape of the catheter forming the delivery means. The said support may be moved relatively to the delivery means 80 to allow the placement of markers 81 before use (the number of markers may be varied according to the length of the support 82 that protrudes from the tip 3) and also this length may be adjusted each time a marker 81 has been attached to tissue 5. Figure 53 illustrates a further embodiment of the invention. In this embodiment, the marking means is formed by the injection of a fluid, for example a radio opaque fluid, inside the tissue 5, where the marking has to be done. Typically in this embodiment, the system comprises a delivery device 90 in the shape for example of a catheter with a tip 91 where the fluid may be delivered in the tissue, thus marking a desired location 93 in the tissue 5. The marking 93 being radio opaque, it may be seen later on images taken of the marked patient. This embodiment may be used in the same manner as the other embodiments previously described whereby successive locations 93 in a patient are marked, for example where a surgical treatment has been carried out.

Of course, all the embodiments described in the present application should not be construed in a limiting manner but only as illustrative examples of possible realizations. Other embodiments are possible and may be envisaged by a skilled person, for example using equivalent or similar means, within the frame and scope of the present invention. Also, the different embodiments described herein may also be combined together according to circumstances. As a skilled person will understand from the above description, the marker should be radio-opaque, for example made in metal or comprise a metallic part. Particularly radio-opaque metals such as platinum, gold, iridium or their alloys could be used for marker or its parts fabrication to improve its visibility under fluoroscopy. Of course, other materials may be envisaged depending on the visualization techniques used in a case such as radio opaque fluids which are known in the prior art.

The present invention is not limited to the marking of ablated tissue and the process of marking could be used in combination with other treatment of tissue than ablation. In fact, many treatment and diagnostic modalities could be improved by their combination with the marking so that the treated part is marked and recognizable during time. As an example, the marking could be combined with visualization means (for example fluoroscopy, 3D mapping, 3D volume reconstruction, etc.) to identify specific parts of a patient and mark them appropriately for future treatment, imaging, 3D anatomy reconstruction etc. This approach would allow a realistic or real marking of places (typically in the body of a patient) that can then be imaged and the marks could thus be used as reference points. Such points would have the advantage of being dynamic, i.e. they will move with the marked places or organ thus providing a real and dynamic information about (for example) the position of said places or organ which can be very useful in interventional and surgical procedures. Of course, this is only an example of possible use and other applications may be envisaged by a skilled person.

Claims

1 . A system for marking tissue surface, for example of a hollow organ in the body of a patient, wherein said system comprises a catheter with a head and a marking means for delivering at least one marker, wherein said head and said marking means are in close proximity such that the marker is delivered substantially to the zone of tissue compression by said catheter head.

2. The system as defined in claim 1 , wherein the catheter is an ablation catheter with an ablation head.

3. The system as defined in one of the preceding claims, wherein the marker is self attachable to said tissue.

4. The system as defined in one of the preceding claims, wherein the marker is self-deformable.

5. The system as defined in one of claims 2 or 3, wherein said marker is self- attachable or self-deformable by application of heat.

6. The system as defined in one of the preceding claims, wherein said marker has the shape of a staple, a star, a nail, a screw, a harpoon, a coil, a clip, or a needle or another similar shape.

7. The system as defined in claim 6, wherein said marker is delivered to tissue using mechanical energy, hydraulic energy, shock waves or explosion energy.

8. The system as defined in one of the preceding claims 1 to 6, wherein said marker is made of a shape-memory alloy.

9. The system as defined in one of the preceding claims, wherein said marker is serving for delivering ablation energy.

10. The system as defined in claim 9, wherein said marker is RF energy delivering electrode.

1 1 . The system as defined in claim 9, wherein said marker is delivering energy on tissue surface and/or intramurally.

12. The system as defined in one of the preceding claims, wherein the catheter or the marking means carry a plurality of markers.

13. The system as defined in claim 12, wherein said markers are interconnected allowing their withdrawal from the catheter or the marking means before the marker in contact with tissue is completely released.

14. The system as defined in one of the preceding claims, wherein the marker is placed on the catheter.

15. The system as defined in one of the preceding claims, wherein said marker at least comprises a magnetic part and the catheter comprises a mobile magnetic part for temporary coupling with the magnetic part of the marker.

16. The system as defined in claim 1 , wherein said marking means is a fluid.

17. The system as defined in claim 16, wherein the fluid is a radio opaque fluid.

18. A method for marking the surface of tissue, for example in the body of a patient, whereby said marking is carried out before, during or after a treatment, such that the parts to be treated or the treated parts are marked and carry a durable marking.

19. The method as defined in claim 18, wherein the marking is realized by application of heat such as to provoke the deformation of a marker to be applied.

20. The method as defined in claim 18, wherein the marking is made by application of a fluid.

21. The method as defined in claim 20, wherein the fluid is radio opaque.

22. The method as defined in one of claims 18 to 21 , wherein successive treatment and marking are carried out.

23. The method as defined in one of claims 18 to 22, wherein the treatment is ablation of tissue.