BE1024715B1 - STENT - Google Patents

Abstract

Stent for connecting a first artery to a second artery, the stent having a head and a tail, the tail being elongated with a diameter to radially abut against an inner wall of the first artery in the deployed state of the stent with the tail and wherein the head has a plurality of hook members which, in the deployed state of the stent, extend radially outward so that the head is adapted to hook into an incision in the second artery.

Description

(73) Holder (s):

HAENEN Filip Walter Nicole 2170, MERKSEM Belgium

PALMERS Charlotte 2000, ANTWERP Belgium

HAENEN Luc 2530, BOECHOUT Belgium (72) Inventor (s):

PALMERS Charlotte 2000 ANTWERP Belgium

HAENEN Filip Walter Nicole

2170 MERKSEM

Belgium (54) STENT (57) Stent for connecting a first artery to a second artery, the stent having a head and a tail, the tail being elongated with a diameter to radially expand the stent with the tail pressing against an inner wall of the first artery, the head having a plurality of hook elements which, in the deployed state of the stent, extend radially outwardly so that the head is suitable for hooking through an incision in the second artery.

FIG. 4B

BELGIAN INVENTION PATENT

FPS Economy, K.M.O., Self-employed & Energy

Publication number: 1024715 Filing number: BE2016 / 5755

Intellectual Property Office

International Classification: A61B 17 / 11A61F 2/966 A61F 2/915 Date of Issue: 04/06/2018

The Minister of Economy,

Having regard to the Paris Convention of 20 March 1883 for the Protection of Industrial Property;

Having regard to the Law of March 28, 1984 on inventive patents, Article 22, for patent applications filed before September 22, 2014;

Having regard to Title 1 Invention Patents of Book XI of the Economic Law Code, Article XI.24, for patent applications filed from September 22, 2014;

Having regard to the Royal Decree of 2 December 1986 on the filing, granting and maintenance of inventive patents, Article 28;

Having regard to the application for an invention patent received by the Intellectual Property Office on the date of 10/10/2016.

Whereas for patent applications that fall within the scope of Title 1, Book XI, of the Code of Economic Law (hereinafter WER), in accordance with Article XI.19, § 4, second paragraph, of the WER, the granted patent will be limited. to the patent claims for which the novelty search report was prepared, when the patent application is the subject of a novelty search report indicating a lack of unity of invention as referred to in paragraph 1, and when the applicant does not limit his filing and does not file a divisional application in accordance with the search report.

Decision:

Article 1

HAENEN Filip Walter Nicole, Azalealei 121, 2170 MERKSEM Belgium;

PALMERS Charlotte, Verbondstraat 18,2000 ANTWERP Belgium;

HAENEN Luc, Vinkenstraat 11, 2530 BOECHOUT Belgium;

represented by

PHILIPPAERTS Yannick, Meir 24 box 17, 2000, ANTWERP;

a Belgian invention patent with a term of 20 years, subject to payment of the annual fees as referred to in Article XI.48, § 1 of the Economic Law Code, for: STENT.

INVENTOR (S):

PALMERS Charlotte, Verbondstraat 18,2000, ANTWERP;

HAENEN Filip Walter Nicole, Azalealei 121, 2170, MERKSEM;

PRIORITY:

BREAKDOWN:

Split from basic application: Filing date of the basic application:

Article 2. - This patent is granted without prior investigation into the patentability of the invention, without warranty of the Merit of the invention, nor of the accuracy of its description and at the risk of the applicant (s).

Brussels, 04/06/2018,

With special authorization:

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BE2016 / 5755

Stent

The present invention relates to an aid and method for realizing an atrial anastomosis.

Regular so-called bypass operations are performed in cardiac surgery.

When veins narrow, for example due to an unhealthy lifestyle or due to old age, the heart muscle gets less blood. This can lead to various discomforts and even to a fatal heart attack. Bypass surgery bridges the narrowing, using other pieces of vein, so that the heart muscle gets enough blood again. The known method for performing so-called bypass surgery involves performing a sternotomy, which is extremely invasive for the patient. The time for rehabilitation after such an operation is also long, making it an expensive operation.

The invention originated from a quest to connect the coronary artery, also known as the left descending anterior artery (LAD) on the heart and thoracic artery, also known as left internal mammary artery (LIMA) in the chest, in a less invasive manner in order to bridge narrowing of the LAD.

It is an object of the invention to provide an aid for connecting two arteries.

To this end, the invention provides a stent for connecting a first artery to a second artery, the stent having a head and a tail, the tail being elongated with a diameter in the deployed state of the stent with the tail radially against a pressing the inner wall of the first artery, and wherein the head has multiple hook elements which, in the deployed state of the stent, extend radially outwardly so that the head is suitable for hooking through an incision in the second artery.

In the problem statement described above, the stent forms a connector for connecting the LIMA and the LAD. More specifically, the stent will be introduced with its head forward into the LIMA. This can be done, for example, by means of a catheter with a guide wire that is inserted through the groin into the LIMA. Endoscopic tools can be introduced into the chest cavity through one or more incisions in the chest. Using the endoscopic tools, the Surgeon can detach the LIMA from the chest wall and cut it so that the LIMA has an open end. The surgeon can also prepare the LAD through the endoscopic tools, in particular make an incision in the wall of the LAD at a position determined by the surgeon. This position is typically chosen immediately after a narrowing of the LAD, which is narrowed. The LIMA can then be moved towards the incision with its open end. Thereby, the stent is advanced in the LIMA until

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BE2016 / 5755 the head of the stent emerges from the open end of the LIMA, with the head extending further through the incision into the LAD. Deploying the stent in this position results in the hook elements hooking into the LAD because the hook elements extend radially outward. This prevents the stent from moving its head out of the incision. Thus, the head of the stent hooks into the LAD through the incision. By further deploying the stent, the tail of the stent will press radially against an inner wall of the LIMA. Because the tail of the stent presses against the inside of the LIMA, the LIMA is retained by the stent. With its head, the stent will be trapped in the LAD, while the stent with its tail will hold the LIMA. The stent thereby forms a link between the LAD and the LIMA. This connection can be achieved by a combination of catheterization and endoscopy, so that a sternotomy can be avoided. The stent according to the invention makes it possible to realize a LAD bypass in a minimally invasive manner.

During the research and development of the stent to perform a LAD bypass in a minimally invasive manner, it has been found that the stent has a wider scope than just the procedure described above. In particular, the stent can be used to realize an anastomosis between two arteries in a simple manner. Conventionally, anastomoses are performed manually with a wire of about 0.2 mm. In addition, manual anastomosis between two arteries can easily take ten minutes. Surgeons often perform such anastomoses in hard-to-reach places in the body. Due to the limited freedom of movement and access to the site of the anastomosis, the realization of a good anastomosis requires a lot of craftsmanship, experience and knowledge. The tools used for this are also expensive. The stent according to the invention considerably simplifies the realization of an arterial anastomosis. The stent makes manual suturing completely unnecessary, and only requires proper stent deployment and deployment. It should be noted that artery preparation and positioning of one artery relative to another is also required when manual anastomosis is achieved.

Although the stent of the present invention has been initially developed to position by means of a guidewire catheter, the stent may be alternatively positioned in certain situations. For example, when performing open heart surgery that connects a coronary artery to the open heart, the stent may be inserted through the open heart with its tail forward to connect the artery to the heart wall. The hook elements hook onto an inner side of the heart wall, while the tail presses radially against an inner side of the heart artery. In such a situation, the stent can be deployed without a catheter.

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The stent deployment mechanism can be formed in various ways. Preferably, the stent is resilient so that the stent has a natural tendency to deploy. Thereby, the stent is sheathed by a sheath to bring the stent into its desired starting position, after which the sheath is removed in a controlled manner so that the stent deploys to an end position. Alternatively, a so-called balloon may be provided in the stent, which balloon is inflated when the stent is in a desired position, the inflation of the balloon controlling the deployment of the stent.

Preferably, the tail has a plurality of deployed stent extensions of the stent that act as a barb to at least partially prevent axial displacement of the tail relative to the inner wall. Further preferably, the plurality of protrusions extend at least partially radially outward from an outer surface of the tail in the deployed state of the stent. Preferably, further, the plurality of projections extend at least partially toward the head of the stent. After realizing the connection of the first artery to the second artery by means of the stent, it will always be the intention that blood will flow through the first and second arteries again. Arteries act to transport oxygenated blood to the various parts of the body and organs. As a result, the internal pressure in arteries will be increased by the heart. This internal pressure will always cause the first artery to move away from the second artery. By providing barbs in an outer surface of the tail, which barbs preferably extend radially outward and toward the head of the stent, the barbs will engage the inner wall of the first artery when this artery tends to move away. moving the second artery. The barbs hold the first artery at a predetermined position relative to the tail of the stent, allowing for a firm connection.

Preferably, each hook member has a distal end that extends at least partially toward the tail of the stent in the deployed state of the stent. Furthermore, preferably, the distal end of each hook member, in the deployed state of the stent, is radially spaced from the tail. The distance is preferably at least 0.3 mm, more preferably at least 0.4 mm. Furthermore, preferably each hook member has a proximal end which, in deployed state of the stent, extends substantially in line with the tail and each hook member includes a curved hook segment connecting the proximal end to the distal end. By constructing the hook element in such a way, it is optimized to extend through the incision and to hook radially outwardly in the second artery, behind the incision. Because the hooks are bent and the distal end of the hook extends towards the tail, the hook elements will be able to pin into the inner wall

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BE2016 / 5755 of the second artery, around the incision. Because the hook elements can pinch, displacement of the hook elements, for example by shifting, is prevented. This makes it possible to build up internal pressure in the second artery by streaming the blood without the incision widening and leaking. Namely, the hook elements hook on the inner wall of the second artery around the incision. The hook elements, because the distal ends extend toward the tail, can snap into this inner wall. The hook elements hold the inner wall of the second artery, at the location of the incision, correctly positioned. Also, as the pressure in the first and second arteries is increased, the head will tend to move out of the incision. Because the head retains and is punctured around the incision, the movement of the head through the incision is prevented so that the stent remains correctly positioned.

Preferably, the hook elements include at least six hook elements that are distributed around a circumference of the stent. Preferably, the hook elements also include at least eight hook elements that are distributed around the circumference of the stent. By providing at least six, preferably at least 8, hook elements and spreading them around the circumference of the stent, a good distribution of pressure around the incision can be achieved.

Preferably, in the pleated state of the stent, the tail and head extend mainly as a cylinder of substantially constant diameter, so that the tail and head are in line. This allows the stent to move in the first and second arteries so that the stent is correctly positionable.

Preferably, the stent is made from nitinol. Nitinol is a material known for its resilience and strength. Nitinol is also known to cause little or no unwanted reactions in the body.

The invention further relates to a set of a catheter and a stent, the catheter including a deployment mechanism for the stent, and the catheter further connected to a guidewire coupled to the deployment mechanism to operate deployment of the stent. The stent can be positioned via the catheter and guidewire. Since a stent deployment mechanism is provided and coupled to the guidewire, the stent can be deployed in a controlled manner after the stent has been positioned correctly. Because the deployment mechanism is connected to the guidewire, deployment of the stent can be controlled and driven from outside the body, further supporting its minimally invasive character.

Preferably, the deployment mechanism is constituted by a sleeve provided to envelop the stent in the deployed state, and wherein the sleeve is movable over the stent, the movement being drivable via the guidewire. The stent is then preferably

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BE2016 / 5755 made of a resilient material that tends to move in the deployed position. When the sheath is moved over the stent to shear off the stent, the stent will deploy and assume its deployed condition and shape.

The invention further relates to a method for connecting a first artery to a second artery, the method comprising:

preparing the first artery so that the first artery has an open end that is movable;

making an incision in a wall of the second artery; moving from the open end of the first artery to the incision;

positioning the stent of any one of claims 1-11 so that the tail of the stent extends into the first artery and so that the head of the stent extends through the open end and through the incision into the second artery;

deploying the stent so that the hook elements hook into the second artery while the tail of the stent presses against an inner wall of the first artery to connect the first artery to the second artery.

Preferably, the first artery is the LIMA, the second artery is the LAD, and the step of positioning by means of a catheter with guidewire is performed through the LIMA.

The invention will now be described in more detail with reference to an exemplary embodiment shown in the drawing.

In the drawing:

Figure 1 shows a catheter with operating device and stent according to an embodiment of the invention;

Figure 2 shows a detail of a catheter with a stent;

Figure 3 shows a detail of a hook element of a stent according to an embodiment of the invention;

Figure 4 shows a stent according to an embodiment of the invention; and Figure 5 shows a use scenario of a stent according to an embodiment of the invention.

In the drawing, the same or analogous element is assigned the same reference numeral.

To properly understand the context of the present invention and its field of application, the basic anatomy of veins is explained. The aorta with a diameter of about 2.5 cm starts from the heart. The aorta branches several times to distribute the blood in the body. The first branches of the aorta are called arteries or arteries

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BE2016 / 5755 oxygenated blood to the Organs. In the Organs, the arteries branch further into so-called arterioles or small arteries. These then carry the blood to the capillaries or capillaries. After the blood has been transported via the capillaries to the Organs, which capillaries are responsible for the metabolism of the blood, the blood flows low in oxygen to the venules, being the smallest blood vessels of the venous system. The venous system is the system that returns deoxygenated blood back to the heart. The venules are joined together again into small veins, which in turn send the blood to the medium and large veins before it enters the venae cava, or pulmonary veins. For functional reasons, the wall of a peat is much thinner than the wall of an artery. An artery or artery has more elastic fibers and smooth muscle, allowing the arteries to absorb pressure changes in the bloodstream. In particular, the stent of the invention is optimized for artery splicing. The stent is designed to accommodate the high pressures and pressure changes that typically occur in arteries. Veins, unlike veins, are elastic and relatively strong.

The LIMA, left internal mammary artery, is a chest artery that runs across the chest, about 1 cm from the breastbone. The chest artery rises in the aorta and carries blood to the chest. He branches and continues to the gate where he also supplies blood. The LAD, left descending anterior artery, is a coronary artery that supplies blood to the left side of the heart.

Constriction of the coronaries can occur in the heart. That is, the heart arteries are narrowed and less blood can flow through them. The effect of this is that the heart muscle can become deficient in oxygen and it can function less or less and pump.

If oxygen cannot or hardly reach the heart muscle, it can die. This phenomenon is called myocardial infarction and can be fatal without surgery.

A condition as described above can be resolved by a so-called bypass operation. It diverts arteries to the right place on the heart in order to bridge a narrowing. Veins can be removed from the leg or arm, but preferably the chest artery (LIMA) is used. A peat is a less qualitative candidate for a bypass because of its irregular structure. An artery has a thicker muscle wall, which makes it very elastic.

A bypass is literally a diversion of blood flow. A diversion can be used with any coronary. In the context of this description, the connection between the LIMA and the LAD will be discussed in particular. However, the description is not limited to this connection, and will also include connections from other arteries.

The LIMA is located in the chest wall and the LAD is on the left side of the heart. In a bypass with these two veins, the surgeon typically opens the chest completely through a sternotomy. A lot of preparation is involved in such an operation. The

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BE2016 / 5755 patient must be prepared to go to the heart-lung machine so that the heart and lungs can be shut down. This is a noteworthy risk, especially in elderly patients. The LIMA is removed from the chest and tested for good blood flow. Typically, the surgeon has acquired prior knowledge of the location of the fresh topping in the LAD, for example, through an angiography. The surgeon then positions the LIMA and the LAD and performs an anastomosis, also called suture, to connect them. An anastomosis is traditionally performed with a thin wire of about 0.2 mm. To prevent leakage of blood, glue is applied over the joint. The glue typically disappears after a short time and allows the tissue to grow together. Once a good connection has been made, the patient is prepared to be removed from the heart-lung machine. The patient is also closed again. The chest is typically tied together with stainless steel wire. Such an operation is very invasive and the patient stays in the hospital for an average of ten days. After the procedure, the patient must rehabilitate for two to three months.

An endoscopic procedure is minimally invasive to the patient. Such a procedure typically requires several small incisions between the ribs of 0.5 to 1 cm on average. Tubes or ports are installed through the incisions through which the surgeon's instruments are placed. One input is typically used for the endoscope, a camera the surgeon uses to monitor the procedure. Other inputs are typically used for instruments used to perform the procedure. The instruments can be easily replaced, and attachments and materials can also be passed on. For example, a suture body can be introduced through a gate. Such a gate is also referred to by law as a trocar.

Stents are known and widely used in the medical world. A stent is formed by a metal or plastic tube that has a pleated and a deployed state. In the crimped state, the stent is compact, the purpose of which is to allow the stent to be transported through the body through a blood vessel. In the deployed state, the stent takes a shape to perform its function, for example, widening a vein.

There are two types of stents, in particular stents with two deployment mechanisms.

A first type of stent is a self-expanding stent, also called a self-expandable stent. A second type of stent is a balloon deployed stent, also known as a balloon-expandable stent. A balloon-expandable stent is placed on a balloon catheter prior to surgery. A self-expandable stent comes preformed on the catheter in a sheath, also called a sheath, that keeps the self-expandable stent compact on site. In such an embodiment, the stent is typically slid out of the sheath, or the sheath is slid away from the stent when the stent is positioned in the body.

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Such stents are often made of super-elastic memory material such as nitinol or nickel or titanium. Such a stent typically consists of a metal structure that is compressed on a crimper. The metal structure, which is typically mesh, allows the threads to easily move together to reduce the diameter from 2 to 3 mm to about 1 mm.

The stent is preferably made from a cardiovascular biomaterial. The most commonly used materials for stent are steel, titanium, cobalt chromium and nitinol. They have good biocompatible properties.Cardiovascular biomaterials are materials that can reside in the heart arteries and promote their action. Nitinol is an alloy of titanium and nickel. Due to its memory properties and elasticity, this material is often chosen in cardiovascular procedures. The memory properties of this material are related to temperature. If a nitinol stent has its shape at about 30 °, it can be squeezed in a colder environment and it will stay that way until it gets back to the temperature of 30 ° where it will unfold to its pre-formed shape. Nitinol is also relatively resistant to stress and deformation. In an artery or artery, a nitinol stent works outward with a slight force, but is again deformed with great force. Alternatively, polymers such as polyamide (nylon) can be used in cardiovascular applications.

To improve a connection between two arteries, an adhesive can be used. An example of glue is CryoLife's BioGlue, which is a biological surgical glue consisting of Glutaraldehyde and concentrated bovine albumin.

Three stages can be distinguished in the stent delivery method. The first phase is the transport phase in which the stent is transported through the arteries to the correct location. The second phase is the localization phase in which the correct peak is located in the narrowed artery so that the stent can be brought to this peak. The third phase is the transformation phase in which the stent is transformed from its pleated state.

The stent is transported through the catheter on which the stent is attached. The catheter is typically inserted through the groin and transports through the femoral artery, abdominal aorta, aorta and finally the LAD. Those skilled in the art will understand that transportation and the distance traveled depend on the desired location of use of the stent.

The stent according to the invention provides a connecting system that can connect two arteries in a qualitative manner and allow blood flow between the two arteries. The stent can be compactly introduced into the body and given a specific location that is different for each patient. The stent is constructed to undergo a transformation that adapts it to the arterial environment to perform the functions described below.

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In an alternative method, when the stent is introduced into the body through endoscopic instruments, the transporting step is performed alternatively and without a catheter.

The stent can be made by weaving nitinol wire, or by laser cutting a nitinol tube. Preferably, the stent is made from a nitinol tube. Tests and simulations have been performed to determine an optimal material thickness for the stent. These tests and simulations were done with a nitinol tube with a tube thickness of 0.1 mm, with the meshes cut out to leave a material width of 0.2 mm. Simulations showed that when it comes under a predetermined pressure, the yield strength is exceeded and the material thus deforms plastically. The predetermined pressure is determined in function of the arterial connection, taking into account the blood pressure and the blood pressure variation and the associated forces this causes on the stent material. A second and a third simulation were performed with a tube thickness of 0.2 mm and 0.3 mm respectively. The tube with a tube thickness of 0.3 mm turned out to be very strong but probably too thick to be used as a stent. The hook elements would come out too much, so that the diameter becomes too large and the interior space of the LIMA and / or LAD would fill up too much. From this it can be concluded that it is safe to manufacture a stent with a material thickness of 200 micrometers +/- 70 micrometers, preferably +/- 50 micrometers, more preferably +/- 30 micrometers. A stent with such a material thickness will not take up too much space for the blood flow and the elasticity of the LIMA allows to create extra space by pushing on the wall.

Figure 1 shows a stent 1 mounted on a distal end of a catheter 7.

The stent 1 is kept compact by a sheath 2. The figure illustrates how a guidewire 3 is used to guide the catheter 7 to the desired location. The guidewire 3 can be first inserted into the artery, or it can be inserted together with the catheter. At the proximal end of the catheter and the guidewire 3, an operating device 4 is provided. The operating device 4 comprises a moving element 5 and a base element 6 which are mutually connected by means of screw thread. The moving element 5 can be rotated with respect to the base element 6 so that, by rotation, the moving element 5 is displaced with a predetermined and known distance from the base element 6. The movable part 5 is connected to the sleeve 2 which is is located around the stent 1 such that the sleeve can be removed from the stent 1 in a controlled manner by rotating the moving element 5 relative to the base element 6. For example, the screw thread may have a pitch of 1 mm, so that the moving element 5 moves by 1 mm with each rotation relative to the base element 6.

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Figure 2A shows a detail of a stent according to an embodiment of the invention in the collapsed position on the catheter. Figure 2B shows the same stent in a state where the sheath has been partially moved backward to deploy the stent hook members. In addition, figure 2 shows the stent 1, the sheath 2 and figure 2B also illustrates well that the catheter 7 has a basic body 8 which has a notch in its outer surface in which the stent in the folded state fits. The sheath is then slid over the notch so that the stent is reliably transportable through the body in a crimped condition.

Preferably, visual markings, e.g., color markers, are provided on the catheter 7 to enable tracking and control of positioning of the catheter via the endoscope. Preferably, in addition to visual markings, "radiopaque" markings are also provided such that the radiopaque markings can be visualized via the X-ray machine.

A first marking is preferably provided at the location of the hook elements of the stent 1, a second marking different from the first marking is provided directly behind the hook elements in the folded state of the stent 1, and a third marking is provided at the height of the tail of the stent, as will be discussed in further detail below, wherein the third marker is different from the second marker. The first mark and the third mark may be the same or different. The markings assist the surgeon in positioning the stent 1.

The transformation method of the stent according to the invention preferably takes place in three steps. In the first step, the stent is inserted through an incision in the second artery, after which the sheath is slid over the hook members so that the hook members move outward. The second step in the transformation is to slide the sleeve further about five mm from the tail, so that the part of the tail, which is located at the location of the head with the hook elements, folds open to mainly its final diameter. This also puts the hook elements in their final position. Typically, the stent is then pulled back so that the distal ends of the hook members snap into the wall of the second artery. As a result, the wall of the second artery is fixedly positioned at the incision by the hook elements. In the third step, the sheath can be completely removed from the stent so that the entire tail of the stent presses against the inner wall of the first artery. Before fully deploying the tail of the stent in this manner, typically the first artery is positioned over the stent, as close as possible to the second artery, by endoscopic tools to optimize connection.

Figure 3 shows a detail of a hook element 9 which forms part of the head of a stent 1 according to an embodiment of the invention. The figure further illustrates how the hook element 9 connects to the tubular base body of the stent 1. The stent has a tail

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BE2016 / 5755 and a head 12. The material thickness of the stent, described in detail above, is indicated in the figure with reference numeral d. The hook elements extend over a distance in radial direction indicated by reference numeral a. This increases the diameter of the stent at the head position with the hook elements by a distance equal to 2 x a. The hook elements 9 are bent so that the distal end of the hook member 9 extends toward the tail. Preferably, the distal end of the hook element 9 extends a distance b towards the tail. In addition, tests and simulations have indicated that the thickness d is preferably 200 micrometers +/- 50 micrometers, the distance a is preferably at least 0.3 mm, more preferably at least 0.4 mm, most preferably about 0.5 mm , and the distance b is also preferably a minimum of 0.3 mm, more preferably a minimum of 0.4 mm, most preferably about 0.5 mm.

A stent can be woven, or fabricated via laser cutting or laser cutting. The laser-cut stents have a different cross-section from the woven stents because they are made of tubing while woven stents, as the name suggests, are made of wire material that is coiled along a tube of a predetermined size. The stent according to the invention is, for example, made of tubular material to ensure good workability and reliability of the stent.

After production of the stent, the stent is preferably packaged in a sterile manner. This means that air, moisture and debris cannot get to the stent, so the stent cannot become contaminated.

The cutting and shaping of the stent from the nitinol tube is preferably done so that the stent is cut into its deployed shape. Then, the hook elements are bent to their deployed shape by means of a die, for example a mechanical plug, and so the stent will undergo heat treatment. Due to the heat treatment, the pleated position of the hook elements will be assumed by the stent as the base shape, or shape in the deployed state. This is the shape the stent moves to when external forces are released and when the stent is at a predetermined temperature as described above. In a way, barbs, discussed in more detail below, can be pleated in the correct direction by means of a die and the stent will be heat treated to determine the direction of the barbs.

After forming the stent and performing the heat treatments, the stent is deformed to enter the crimped state. In the case of nitinol, the stent is cooled so that the material can be deformed without losing its so-called memory.

Then the stent can be mounted on the catheter and covered with the sheath so that it is ready for further packaging.

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Figure 4 shows an embodiment of a two-state stent. Figure 4A shows the embodiment in the pleated state, while Figure 4B shows the stent in the fully deployed state. In addition, Figure 4 shows how the stent has a tail 11 and a head 12. Tail 11 and head 12 are preferably directly connected to each other and formed as a single unitary assembly. At the location of the head 12, the stent 1 is provided with hook elements 9. In the pleated condition of the stent 1, the hook elements 9 extend substantially parallel to the tubular shape 10 of the tail 11. In the deployed condition of the stent, the hook elements 9 from the tail 11 outward and preferably curved so that the distal end of the barbs extends towards the tail 11. Figure 4 further shows how the tubular shape 10 of the tail 11 is provided with barbs 13. The barbs 13 extend radially from the surface of the tail 11 in deployed state. Furthermore, the barbs 13 extend towards the head 12 of the stent 1. In the unloaded state, the barbs 13 preferably have an angle with respect to the outer surface of the tail of maximum 30 °, preferably maximum 20 °. The barbs extend over a distance of about 100 micrometers. Figure 4 further illustrates how the stent in a collapsed state has a diameter V significantly smaller than the diameter W of the stent in a deployed state. Preferably 2xV <W.

Furthermore, in figure 4 it is indicated where markings 18, 19 and 20 are preferably made. As described above, the markings may be visual markings and / or radiopaque markings. The head of the stent 1 is preferably provided with a first marking 18, while a second marking is provided directly behind the head. The tail of the stent may further be provided with a third mark 20. The third mark 20 may extend over the full length of the tail, or over a segment thereof.

A preferred use scenario and method for using the stent according to the invention will now be described with reference to Figure 5. This usage scenario relates to bridging the LAD using the LIMA. Based on this use scenario, those skilled in the art will clearly understand that other arteries can also be joined using the stent of the invention and via a method similar to the method described below.

The patient goes under complete anesthesia and has three incisions of approximately 1 cm. Endoscopic tools are passed through the incisions. These tools can always be changed during the procedure. The surgeon detaches the LIMA from the chest wall via the endoscopic tools. The LIMA is cut to create an open end that is movable in the chest space. Preferably a piece of fat is stored at the open end, so that the

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BE2016 / 5755 surgeon can easily grab it later. When the LIMA is loose, a so-called bulldog clip can be placed on it, so that no more blood flows through it.

The stent is transported to the LIMA using the catheter. This is typically performed by the cardiologist using X-ray images showing the blood vessels of the patients.

The surgeon also prepares the LAD. Typically, a needle is placed under the LAD for this, with which the LAD is clamped. Thus, the blood flow in the LAD is stopped. This action ensures that the LAD stretches itself thickly and that it becomes much more visible on the heart. This simplifies the further actions that are carried out on this. In the outer surface of the LAD, the surgeon makes an incision at a predetermined location of a predetermined length, for example, from about 2 to 2.5 mm. In Figure 5, the LAD is shown as the second artery 15, with the incision 16. The LIMA is shown as the first artery 14 with the open end 17.

After the LIMA and LAD have been prepared in the manner described above, the surgeon can move the LIMA with its open end 17 to the incision 16 of the LAD.

For this, the surgeon can grasp the fat lobe. The cardiologist can then gently move the catheter toward the LAD 15 while the surgeon holds the LIMA 14 at its peak with an endoscopic clamp. The visual markings on the catheter described above allow the surgeon to see if the catheter is deep enough or not too deep in the LAD. Since the wall of the LAD has an average thickness of 1 mm, the first mark 18 on the catheter preferably extends over a distance of 1 mm. Those skilled in the art will understand that the width of the first marker 18 is adaptable to the application.

The head of the stent is properly inserted into the LAD when the first marker is in the LAD. A second mark follows the first mark. This dash of between half and one millimeter is yet to be seen by the surgeon. He then signals that one is in the right place. Furthermore, there is a third mark 20 which indicates that one is past the two mark when it is no longer visible. The cardiologist can also follow on a screen.

With "radiopaque" markers, he can see where he is in the artery.

When the catheter is properly positioned, the deployment of the stent may begin.

By giving the operating device 4 a half turn, the cardiologist can start the deployment. He pivots the moving element 5 backwards and keeps the basic element 4 stable in his hand.

By rotating the base element 4 backwards, the sleeve 2 of the catheter automatically follows.

The control device 4 preferably has a few pictograms 10 which indicate the position of the sleeve 2.

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The cardiologist first makes a half turn with the operating device 4.

When he encounters the first pictogram, he knows that the hook elements 9 of the stent are deployed, which he can also verify on the screens. When the first deployment step is complete, the second unfolds. The diameter of the stent now folds open and pushes the wall of the LAD aside. The cardiologist must now hold the operating device 4 in the same position and must then pull the catheter manually and gently to prick the hook elements 9 into the wall of the LAD.

Preferably, the surgeon helps by using an atraumatic clamp, which is a small one without teeth that does not cause damage to the tissue. The surgeon pushes the clamp onto the LAD and helps the hook elements pierce the tissue.

The hook elements should not pierce completely through the fabric, but should preferably pierce about halfway. Therefore, the hook elements are preferably half a millimeter in length. When the hook elements are punctured in the tissue, the cardiologist can fully deploy the stent by rotating the motion element 5 of the operating device 4 fully towards the base element 6. This is equivalent to deploying the entire stent. To help the stent maintain its final position optimally, the stent is equipped with barbs on the outside of the tail, which fold out thanks to the elastic nitinol material when deployed. The barbs puncture the wall of the LIMA and anchor the stent in this way. The barbs do not pierce the tissue because they are only 300 micrometers long.

Once all previous steps have been completed, the stent is correctly positioned. Optionally, an adhesive can be applied at the junction of the arteries. Finally, the cardiologist and surgeon can remove the Instruments from the patient and close the wounds.

Based on the above description, those skilled in the art will understand that the stent is not only applicable for connecting the LAD and the LIMA, but that the stent is suitable for connecting two arteries in a more general context. Therefore, the scope of the stent is noticeably wider than any other for connecting the LAD and the LIMA.

Based on the description above, those skilled in the art will understand that the invention can be practiced in different ways and on different principles. In addition, the invention is not limited to the above-described embodiments. The above-described embodiments, as well as the figures, are merely illustrative and serve only to enhance the understanding of the invention. Therefore, the invention will not be limited to the embodiments described herein, but is defined in the claims.

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Legend of the figures

1. stent

2. sleeve

3. guide wire

4. control device

5. movement element

6. basic element

7. catheter

8. catheter basic body

9. hook elements

10. tube shape

11. tail

12.head

13. barbs

14. first artery

15. second artery

16. incision in second artery

17. open end of the first artery

18. first marking

19. second marking

20. third marking

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Claims (10)

Conclusions A stent for connecting a first artery to a second artery, the stent having a head and a tail, the tail being elongated with a diameter about 5 in the deployed state of the stent with the tail pressed radially against an inner wall of the first artery, the head having a plurality of hook elements which, in the deployed state of the stent, extend radially outwardly so that the head is adapted to to hook an incision in the second artery. 2. The stent according to claim 1, wherein the tail has a plurality of protrusions in the deployed state of the stent which act as a barb to at least partially prevent axial displacement of the tail relative to the inner wall. The stent of claim 2, wherein the plurality of protrusions extend at least partially radially outward from an outer surface of the tail in the deployed state of the stent. 15 The stent according to claim 2 or 3, wherein the plurality of projections extend at least partially toward the head of the stent. The stent according to any of the preceding claims, wherein each hook member has a distal end which, in deployed state of the stent, extends at least partially toward the tail of the stent. 20 The stent according to claim 5, wherein the distal end of each hook member, in deployed state of the stent, is radially spaced from the tail. The stent according to claim 6, wherein the distance is at least 0.3 mm, preferably at least 0.4 mm. 8. Stent according to any one of claims 5-7, wherein each hook element has a proximal end which, in deployed state of the stent, extends substantially in line with the tail, and each hook element further comprises a curved hook segment which extends the proximal end to the distal end. The stent according to any of the preceding claims, wherein the plurality of hook elements includes at least 6 hook elements that are distributed over a circumference of the stent. 10. The stent according to any one of the preceding claims, wherein the tail and the head in the pleated state of the stent extend mainly as a cylinder of substantially constant diameter, so that the tail and the head are in line. The stent according to any of the preceding claims, wherein the stent is made of nitinol. 2016/5755 BE2016 / 5755 The set of a catheter and a stent of any preceding claim, wherein the catheter includes a deployment mechanism for the stent, the catheter further connected to a guiding action coupled to the deployment mechanism to operate deployment of the stent. 13. The set of claim 12, wherein the deployment mechanism is formed by a sheath provided for enveloping the stent in the deployed state, and wherein the sheath is movable over the stent, the movement being drivable via the guidewire. A method of connecting a first artery to a second artery, the method comprising: 10 - preparing the first artery so that the first artery has an open end that is movable; making an incision in a wall of the second artery; moving from the open end of the first artery to the incision; positioning the stent of any one of claims 1-11 so that the tail of the stent extends into the first artery and so that the head of the stent extends through the open end and through the incision into the second artery; deploying the stent so that the hook elements hook into the second artery while the tail of the stent presses against an inner wall of the first artery to connect the first artery to the second artery. The method of claim 14, wherein the first artery is the LIMA, the second artery is the LAD, and the step of positioning through a catheter with guidewire is performed through the LIMA. BE2016 / 5755 BE2016 / 5755