WO2022037776A1

WO2022037776A1 - Cannula, heart assist system, kit and method

Info

Publication number: WO2022037776A1
Application number: PCT/EP2020/073246
Authority: WO
Inventors: Torsten Heilmann; Sabine Post
Original assignee: Reco2Very Therapies Gmbh
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2022-02-24
Also published as: DE112020007521T5

Abstract

Cannula, heart assist system and method for cannulizing a heart. Disclosed is a cannula (O1) for insertion into the left atrium (LA) of a heart (H) via the coronary sinus vein (CSV), wherein the cannula (O1) comprises a cannula body (O1B), which, in a base state of the cannula (O1), has a first section (S1), a second section (S2) and a bended intermediate section (K) connecting the first section (S1) and the second section (S2),. The first section (S1) extends from a distal end (DO1) of the cannula body (O1B) to the intermediate section (K). The second section (S2) extends from the intermediate section (K) in the direction of a proximal end (PO1) of the cannula (O1). The cannula (O1) is configured such that, when inserted as intended, the second section (S2) is located in and extends along the coronary sinus vein (CSV) and the first section (S1) projects into and ends in the left atrium (LA) of the heart (H). In the base state, a bending angle of the intermediate section (K) is at least 45° and at most 135°. Furthermore, a heart assist system, a kit and a method for cannulizing a heart are disclosed.

Description

Cannula, heart assist system, kit and method

The invention relates to a cannula for insertion into the left atrium of a heart. Furthermore, the invention relates to a heart assist system, a kit and a method for cannulazing a heart.

The basic principle of an endovascular catheter/cannula therapy may be a treatment of vessels and/or by using vessels for the advancement of a catheter/cannula, for instance plastic tubes or plastic tubes that are armed with metal. An incision for introducing the catheter may be made into the skin of a patient. The incision may have a length that is less than 5 cm (centimeter), less than 3 cm or less than 1 cm. Local anesthesia may be used thereby.

No thoracotomy may be necessary if cannulas or catheters are used. A cannula may be a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of data. A catheter may be a thin tube made from medical grade materials serving a broad range of functions. Catheters may be medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Both terms, “cannula” and “catheter”, are used interchangeable in the following if not stated otherwise.

By modifying the material or adjusting the way cannulas/catheters are manufactured, it is possible to tailor them for cardiovascular, urological, gastrointestinal, neurovascular, and ophthalmic applications. A catheter/cannula left inside the body, either temporarily or permanently, may be referred to as an "indwelling catheter/cannula" (for example, a peripherally inserted central catheter/cannula).

Catheters and cannulas may be inserted into a body cavity, duct, or vessel. Functionally, they allow drainage, administration of fluids or gases, access by surgical instruments, and/or also perform a wide variety of other tasks depending on the type of catheter or cannula. The process of inserting a catheter is “catheterization”. The process of inserting a cannula is “cannulization”. In particular, a cannula/catheter comprises a flexible or bendable tube and may comprise or consist of a plastic. One object to be achieved is to provide a cannula with which an additional or alternative access route to the heart, particularly to the heart of a mammal or human, can be created. Further objects to be achieved are to provide a heart assist system and a kit with such a cannula. Another object to be achieved is to provide an efficient method for cannulizing a heart.

These objects are achieved, inter alia, by the subjects of claims 1, 10, 13 and 14. Advantageous embodiments and further developments are subject of the dependent claims and may further be extracted from the following description and the figures.

Firstly, the cannula is specified.

According to at least one embodiment, the cannula for insertion into the left atrium of a heart via the coronary sinus vein comprises a cannula body, which, in a base state of the cannula, has a first section, a second section and a bended, i.e. pre-bended, intermediate section connecting the first and the second section. For example, the intermediate section is directly adjoining the first section and the second section.

The cannula body has, e.g. the form of a tube. Preferably, the cannula body is flexible or bendable. The cannula body comprises a lumen or, in other words a channel, for transporting a fluid, particularly blood. The lumen is circumferentially or radially surrounded by a sidewall of the cannula body. For example, the lumen and the sidewall extend over the entire length of the cannula body. Preferably, the lumen and/or the sidewall extend continuously and/or without interruptions over the entire length of the cannula body. The lumen and the sidewall may each follow the shape of the cannula body so that also the lumen and the sidewall each comprises a corresponding first section, a corresponding bended intermediate section and a corresponding second section. The outer and/or inner diameter of the cannula body may be constant within the manufacturing tolerance over the entire length of the cannula body. The length of the cannula or the cannula body may be at least 20 cm or at least 30 cm.

Additionally or alternatively, the length may be at most 80 cm or at most 70 cm or at most 60 cm.

The length of the cannula body is preferably much greater than a diameter of the cannula body, for example at least 20 times or at least 100 times as great as the diameter of the cannula body. The length of the cannula body is herein defined as the distance between a proximal end and a distal end of the cannula body, measured along a virtual midline through the cannula body or the lumen, respectively. The diameter is the extension measured perpendicularly to the midline. The midline may be defined as the line through the cannula body which, in every cross-sectional view along the cannula body and with a cut plane chosen perpendicular to the midline, runs through the center of gravity of the cannula body or of the lumen. The sidewall of the cannula body preferably extends continuously, for example without interruptions, over the entire length of the cannula body. In a cross-sectional view, the lumen may have an elliptical or circular shape. The sidewall may concentrically and/or completely surround the lumen in this cross-sectional view. The diameter of the lumen may be constant over the entire length of the cannula body. “Constant” of course means constant within the manufacturing tolerances.

Here and in the following, a longitudinal or axial direction is defined as a direction along the midline, a radial direction is defined as a direction perpendicular to the midline and pointing away from the midline and an angular direction is defined as a direction perpendicular to the midline and perpendicular to the radial direction. Thus, the directions are defined like cylinder coordinates with the longitudinal direction replacing the z-direction. Here and in the following, the definition of “proximal” is near to the person that inserts the cannula and the definition of “distal” is far from a person that inserts the cannula.

The cannula, particularly the sidewall of the cannula body, may comprise an internal metal scaffold or framework that is for instance spirally wound. However, other frameworks or no framework are also possible. The material of the cannula body or the sidewall may be biocompatible and/or comprise or consist of urethane and/or silicone and/or polyvinyl chloride.

The base state of the cannula is the state in which the cannula is not stressed by one or more external forces applied, e.g., to an outer surface of the cannula body and/or an inner surface of the cannula body. In other words, if no external object induces a force on the cannula, the cannula is in or returns into its base state. Thus, the base state may be considered as the relaxed state or natural state of the cannula. The form of the cannula in the base state may be defined by the metal scaffold or framework of the sidewall. In a non-relaxed state, the cannula or the cannula body is deformed with respect to the base state. The inner surface of the cannula body is herein defined as the surface of the sidewall facing or adjoining the lumen of the cannula. The outer surface of the cannula body is herein defined as the surface of the sidewall facing away from the lumen.

The cannula is, in particular, flexible and bendable such that it is guidable intravascularly along the coronary sinus vein.

According to at least one embodiment, the first section extends from the distal end of the cannula body to the intermediate section. Particularly, the first section starts at the distal end and/or ends at the intermediate section.

A distal end of the cannula body or of a section of the cannula body is here and in the following defined as the distal end of the lumen of the cannula body or of the lumen of the section, respectively. A proximal end of the cannula body or of a section of the cannula body is here and in the following defined as the proximal end of the lumen of the cannula body or of the lumen of the section, respectively. At the distal end and/or at the proximal end, the cannula body may comprise an opening via which the lumen is fluidically coupled to the environment. Fluid, e.g. blood, can stream from the environment into the lumen or can stream from the lumen into the environment via the respective opening. The diameter of the opening(s) may be equal to the diameter of the lumen. The opening at the distal end preferably faces in distal direction. The opening at the proximal end may face in proximal direction. Thus, the midline crosses the respective opening.

Additionally or alternatively, one or more openings may be located in the sidewall in the region close to the distal end and/or proximal end, the one or more openings facing in the radial direction.

According to at least one embodiment, the second section extends from the intermediate section in direction of or towards a proximal end of the cannula or a proximal end of the cannula body, respectively. It is possible that the second section extends to the proximal end of the cannula body or that the cannula body comprises one or more further sections between the second section and the proximal end. The one or more further sections may be straight, when the cannula is in its base state. According to at least one embodiment, the cannula is configured such that, when inserted as intended, the second section is located in and extends along the coronary sinus vein, i.e. the second section is located in and extends along the lumen of the coronary sinus vein. Furthermore, when inserted as intended, the first section projects into and ends in the left atrium.

Preferably, when inserted as intended, the bended intermediate section provides the change of direction of the cannula body which ensures that the first section projects into the left atrium of the heart. In other words, the intermediate section provides the change of direction from the second section, which essentially runs along the main direction of extension of the coronary sinus vein, to a direction transverse or perpendicular to the main direction of extension of the coronary sinus vein, along which the first section extends. When inserted as intended, the intermediate section is preferably placed in a region of the coronary sinus vein directly opposing the left atrium so that the first section can be inserted from the coronary sinus vein into the left atrium without having to pass a ventricle or further atrium of the heart.

The length of the first section is particularly chosen such that the distal end of the cannula body projects into and ends in the left atrium of the heart, when the cannula is inserted as intended. Thus, the length of the first section is, in particular, chosen to bridge over the space between the coronary sinus vein and the left atrium. In particular, the length of the first section is adapted to the distance between an inner region of the left atrium and the lumen of the coronary sinus vein. The first section may partially extend in the lumen of the coronary sinus vein and in the left atrium.

Here and in the following, the length of a section is particularly defined by the length of the lumen in this section and is measured along the longitudinal direction or along the midline, respectively.

According to at least one embodiment, in the base state, the bending angle of the intermediate section is at least 45° or at least 50° or at least 60° or at least 70° or at least 80° or at least 85°. Additionally or alternatively, the bending angle of the intermediate section may be at most 135° or at most 130° or at most 120° or at most 110° or at most 100° or at most 95°. The bending angle may be defined as the angle between a tangent to the midline at the distal end of the intermediate section and a tangent to the midline at the proximal end of the intermediate section. In other words, the cannula/cannula body or the midline of the cannula body makes a curve with the above specified angle, when one goes from the distal end of the intermediate section to the proximal end of the intermediate section. In particular, the intermediate section may be a kink of the cannula with the above defined bending angle being the kink angle.

In at least one embodiment, the cannula for insertion into the left atrium of a heart via the coronary sinus vein comprises a cannula body, which, in a base state of the cannula, has a first section, a second section and a bended intermediate section connecting the first and the second section. The first section extends from a distal end of the cannula body to the intermediate section. The second section extends from the intermediate section in direction of a proximal end of the cannula. The cannula is configured such that, when inserted as intended, the second section is located in and extends along the coronary sinus vein and the first section projects into and ends in the left atrium of the heart. In the base state of the cannula, a bending angle of the intermediate section is at least 45° and at most 135°.

With a cannula formed in this way, the cannula is particularly suitable for being inserted into the left atrium of a heart via the coronary sinus vein. The bended intermediate section allows an insertion into the left atrium without inducing much stress on the coronary sinus vein. The heart mentioned herein is preferably the heart of a mammal, e.g. of a human.

According to at least one embodiment, in the base state of the cannula, the second section is curved, i.e. pre-bended. Thus, in the region of the second section, the cannula body or the midline of the cannula body is not straight but has a curvature.

According to at least one embodiment, the curvature of the second section is adapted to the curvature of the coronary sinus vein. When the cannula is inserted into the heart, the second section preferably extends inside the lumen of the coronary sinus vein. The second section is preferably curved such that it imitates the curvature of the coronary sinus vein. For example, when inserted as intended, the second section of the cannula does not induce mechanical stress to the coronary sinus vein. The curvature radius of the second section may be constant over a large part of the length of the second section or may vary, over a large part of the length of the second section, by at most 20 % or at most 10% or at most 5% from the average curvature radius in this large part. The length of the second section is preferably chosen to be approximately the length of the coronary sinus vein, e.g. with a maximum deviation of 20 % or 10% or 5%. The large part of the length is, e.g., at least 60 % or at least 75 % of the length.

According to at least one embodiment, in the base state of the cannula, the first section, particularly the midline in the first section, is straight, that means not bended or curved. A section being straight of course means that the section is straight within the manufacturing tolerance. Furthermore, a section being straight preferably means that the section is straight over its entire length.

According to at least one embodiment, the second section directly adjoins the intermediate section.

According to at least one embodiment, in the base state of the cannula, a curvature radius of the second section is greater than a bending radius of the intermediate section. In this case, particularly the smallest or average curvature radius of the second section is compared to the smallest or average bending radius of the intermediate section. For example, the curvature radius of the second section is at least 2 times or at least 5 times or at least 10 times greater than the bending radius of the intermediate section. Curvature radius and bending radius are just different names for the same measure, where “bending radius” is used for the curvature radius associated with the intermediate section.

The circle of curvature at a given point of a plane curve is the circle that best approximates the curve at that point. The radius of the circle of curvature is the curvature radius or bending radius, respectively. For determining the curvature radius or bending radius, the midline of the respective section may be used as the plane curve.

According to at least one embodiment, in the base state, the curvature radius of the second section is at least 5 cm or at least 10 cm or at least 15 cm or at least 20 cm. Additionally or alternatively, the curvature radius of the second section is at most 50 cm or at most 45 cm or at most 40 cm or at most 20 cm. In case of a varying curvature radius, the above mentioned values may concern the average or minimal curvature radius.

According to at least one embodiment, a length of the intermediate section is smaller than the length of the first section. For example, the length of the intermediate section is at most 50% or at most 25% or at most 10% of the length of the first section. The length of the second section may be greater than the length of the first section and of the intermediate section. For example, the length of the second section is at least 200 % or at least 500 % of the length of the first section.

According to at least one embodiment, the length of the first section is at least 0.5 cm or at least 1.0 cm or at least 1.5 cm or at least 2.0 cm. Additionally or alternatively, the length of the first section may be at most 5.0 cm or at most 4.0 cm or at most 3.0 cm or at most 2.5 cm or at most 2.0 cm.

According to at least one embodiment, the length of the second section is at least 5 cm or at least 7.5 cm or at least 10 cm. Additionally or alternatively, the length of the second section may be at most 20 cm or most 15 cm or at most 10 cm or at most 7.5 cm.

According to at least one embodiment, the length of the intermediate section is at most 2 cm or at most 1cm. Additionally or alternatively, the length of the intermediate section may be at least 0.2 cm or at least 0.5 cm.

According to at least one embodiment, in the base state, the bending angle of the intermediate section is at least 80° and at most 120°, for example 90°.

According to at least one embodiment, the cannula is a single lumen cannula. This means that the cannula/cannula body comprises only one lumen extending along the midline through which a fluid, particularly blood, can be transported. In contrast to this, double or multi lumen cannulas comprise two or more lumens for transporting fluid, e.g. blood, each lumen extending along the midline and being fluidically decoupled from the other lumens. The lumens of a double or multi lumen cannula may be radially surrounded by a common sidewall of a cannula body. Two lumens being fluidcially decoupled means that no direct fluid transfer, particularly no blood transfer, may be possible between the two lumens. The two lumens may be connected only via a circuitry that is outside of the body into which the cannula is inserted, for instance a circuitry that comprises flexible tubes and/or at least one pump and/or medical devices like an oxygenator, filter etc.

According to at least one embodiment, an inner diameter of the cannula body is at least 6 French or at least 8 French or at least 9 French or at least 10 French. Additionally or alternatively, the inner diameter may be at most 14 French or at most 13 French or at most 12 French or at most 10 French. The unit French is defined such that 3 French are exactly 1 mm.

Here and in the following, the inner diameter of a cannula is defined as the diameter of the inner surface of the sidewall of the cannula body. In case of a single lumen cannula, the inner diameter is the diameter of the lumen. In contrast to this, the outer diameter of a cannula is defined, here and in the following, as the diameter of the outer surface of the sidewall of the cannula body. The thickness of the sidewall may be between 1 French and 2 French, inclusive. For example, the outer diameter of the cannula body is at most 18 French or at most 17 French or at most 16 French. Additionally or alternatively, the outer diameter is at least 10 French or at least 11 French or at least 12 French.

According to at least one embodiment, the cannula comprises a diameter variable arrangement in the region of the distal end, which is configured to increase its diameter in order to secure the first section in the left atrium. In its expanded state, the diameter variable arrangement may project beyond the distal end, defined by the distal end of the lumen, e.g. by at least 2 mm or at least 5 mm or at least 10 mm and/or by at most 30 mm or at most 20 mm or at most 10 mm or at most 5 mm.

As far as the words “diameter variable arrangement” are used in this application, they shall refer to an expandable arrangement that has a first embraced volume in a non-expanded state and a second embraced volume in the expanded state. The second volume may be greater than 2 or 3 or 4 or 5 times the first volume. The diameter may increase also by at least factor 2 or 3 or 4 or more comparing the non-expanded state and the expanded state. However, the second volume may be smaller than 100 or 50 times the first volume. The diameter in the expanded state may be smaller than 20 times or smaller than 10 times the diameter in the non-expanded state, for instance using the maximum diameter in the respective state.

The non-expanded state may be a state in which the diameter variable arrangement can be introduced into the body, e.g. using an introducer that stretches the diameter variable arrangement. When the introducer is removed, the diameter variable arrangement may selfexpand or may be expanded.

The diameter variable arrangement may comprise a cage arrangement. The cage arrangement may comprise wires or stripes. The wires or stripes may be arranged without crossing each other in the portion that has a variable diameter. The wires or stripes may be arranged nearly in parallel when in the non-expanded state. The diameter variable arrangement may be made of a different material compared to the material of the sidewall of the cannula.

A possible material for the wires is a shape memory alloy (SMA) or material, for instance a material that changes its shape depending on the temperature of the material. Nitinol (Nickel Titanium Naval Ordnance Laboratory) is an example for such a material. However, other materials may also be used, for instance NiTi (nickel titan), NiTiCu (nickel titan copper) CuZn (copper zinc), CuZnAl (copper zinc aluminum), CuAlNi (copper aluminum nickel). Further materials that may be used are super elastic materials, stainless steel wire, cobaltchrome alloys or cobalt-chromium-nickel-molybdenum-iron alloy.

The thickness and/or diameter of the wires may be in the range of 0.1 mm to 2 mm, especially if only three or four wires are used within the expandable arrangement that may also be named as cage arrangement. The thickness and/or dimeter of the wires may be in the range of 0.1 mm to 1mm or in the range of 0.25 mm to 0.75 mm. Thinner wires may be useful if more than four wires are comprised within the cage arrangement.

The cage arrangement may comprise a plurality of cage wires that are easy to fabricate and/or easy to pre-bend. There may be 2 to 15 cage wires, preferably 3 to 12 cage wires, i.e. 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 cage wires.

The cage arrangement may comprise in the expanded state of the cage arrangement: - a first or proximal portion in which the distance between neighboring wires increases with increasing distance to a mounting portion of the wires,

- an optional transition portion wherein distance between neighboring wires is constant with increasing distance to the mounting portion of the wires,

- and a third or distal portion in which the distance between neighboring wires decreases with increasing distance to the mounting portion of the wires.

The wires may not have angular overlap between two neighboring wires within each portion and also over all of the portions thus reducing the outer diameter in the non-expanded state. The wires may not cross each other in free portions, crossing may be possible only within a proximal mounting portion of the wires or at the distal end connecting portion. This arrangement of the wires is different form an interwoven or braided material. However, interwoven or braided materials may be used as well as cage arrangements.

The proximal ends of the cage wires of the cage arrangement may be wound around an outer surface of the cannula /sidewall of the cannula, preferably around a distal end portion of the cannula. To coil up wires is a simple but efficient technology for mounting the cage arrangement. Further, the diameter is not increased significantly.

The distal ends of the cage wires may be connected with each other, preferably using a connecting element and/or by twisting them together. The distal ends may be arranged on an extension of the midline in the distal direction allowing the usage of a straight introducer to stretch the respective cage arrangement during insertion.

The cage arrangement may be configured in the expanded mode or state as a sphere or as an ellipsoid. The sphere may have the same radius in all directions in the expanded state. The ellipsoid may have three main axis that have different length or at least one of the main axis may be longer than the other two main axis in the expanded state.

The diameter variable arrangement may comprise a membrane. The membrane may be folded or less stretched in the non-expanded state of the diameter variable arrangement, e.g. it may have lots of wrinkles. The wrinkles may be arranged between supporting structures or outside of spaces that are arranged between such supporting structures, e.g. wires. The membrane may be expanded in the expanded state of the diameter variable arrangement. The membrane may be connected to the diameter variable arrangement using several techniques, for instance dip molding, plastic welding, sewing and/or using glue. The connection technique may also establish a fluid tight connection to the cannula or to a mounting part of the diameter variable arrangement on the cannula.

The material of the membrane may be fluid tight or liquid-tight (impermeable) in both directions, i.e. from inside of diameter variable arrangement (cage) to the surrounding area and/or from surrounding area to inside of cage. Additionally or alternatively, the membrane may define a volume which is fluidically connected to the lumen of the cannula but with a greater diameter than the lumen, especially in the expanded state of the diameter variable arrangement (expandable arrangement). The membrane may be fluid tight and the opening may be an inlet into the lumen or an outlet out of the lumen of the cannula.

The membrane may be or comprise a thin sheet of material, having for instance a thickness of less than 0.5 millimeters, less than 100 micrometer or less than 50 micrometer. However, the membrane may be thicker than 10 micrometer in order to provide appropriate strength. Polytetrafluoroethylene (PTFE) may be an appropriate material for the membrane, preferably if it is manufactured by electro spinning, for instance within an electrical field. However, other materials may also be used. Only one sheet of membrane may be arranged for forming the membrane, e.g. there may be only one layer of membrane material.

In the expanded state of the diameter variable arrangement, an edge of the membrane may define an opening that faces distally relative to the cannula body. This may mean that an edge of the membrane delimits the edge of the opening along the entire circumference of the opening. Preferably the membrane may extends circumferential around an extension of the midline of the cannula body in distal direction by at least 300 degrees or by at least 360 degrees.

Additionally, the membrane may extend from a proximal end of the diameter variable arrangement at most three quarter or at most half way or at most one quarter to a distal end of the diameter variable arrangement. Thus, the membrane may have a lateral sealing function and/or a function in directing an inlet flow or an outlet flow. A membrane having a distally facing opening may have, especially in the expanded state, the following relations relative to the portions of the cage arrangement that are mentioned above:

- the proximal portion and/or the optional transition portion may be covered by the membrane, and

- the distal portion and/or the optional transition portion may not be covered by the membrane.

Next, the heart assist system is specified.

According to at least one embodiment, the heart assist system comprises the cannula specified herein. Moreover, the heart assist system preferably comprises a cannula system with two lumen. The cannula system with two lumen may be a double or multi lumen cannula with all lumens radially surrounded by a common sidewall of the cannula.

According to at least one embodiment, the cannula system comprises a second cannula and a third cannula. The length of the third cannula may be greater than the length of the second cannula, e.g. by at least 5 cm or at least 10 cm. Additionally or alternatively, the length of the third cannula may be greater than the length of the second cannula by at most 20 cm or at most 15. The outer diameter of the third cannula is preferably smaller than the inner diameter of the second cannula. The second and the third cannula may both be single lumen cannulas.

According to at least one embodiment, the third cannula is adapted to be guided into the second cannula, whereby a first lumen is defined between an outer surface of the third cannula, i.e. an outer surface of the sidewall of the cannula body of the third cannula, and an inner surface of the second cannula, i.e. an inner surface of the sidewall of the cannula body of the second cannula. A lumen of the third cannula defines a second lumen. The lumen of the third cannula is defined by the inner surface of the sidewall of the third cannula. The second and the third cannula may be movable relative to each other, particularly, along the longitudinal direction of the second cannula. This movability may be maintained also in the configuration when the third cannula is inserted into the second cannula.

A portion of the second cannula through which the third cannula is guidable within the second cannula may have a length of at least 20 cm or at least 40 cm. The length of the common or overlapping portion may be at most 60 cm length. These length values may be valid for adult persons having a body height in the range of 160 cm to 200 cm. The third cannula may be guidable beyond a distal end of the second cannula by at least 5 cm or by at least 10 cm (e.g. for an adult person). These lengths may be adapted for child body heights between 140 cm and 160 cm.

The features disclosed in connection with the above described cannula, which is herein also referred to as first cannula, are likewise disclosed for the second cannula and/or the third cannula. E.g., the second and/or the third cannula may comprise a diameter variable arrangement in the region of their respective distal end of the respective cannula body. Also the materials, e.g., of the sidewalls of the cannula bodies may be the same.

According to at least one embodiment, the first and the second lumens of the cannula system are fluidically decoupled or separated when the third cannula is inserted into the second cannula. Thus, there is no direct fluid exchange between the two lumens.

According to at least one embodiment, the heart assist system further comprises a pump configured to be connected to the proximal end of the cannula and to suck out blood from a heart, e.g. of a mammal or a human, via the cannula. The pump may be configured to be also connected to a proximal end of the cannula system. Further, the pump may be configured to pump out blood from a heart via the first lumen of the cannula system and to pump blood into the heart via the second lumen of the cannula system.

Next, the kit is specified. The kit may be part of the heart assist system.

According to at least one embodiment, the kit comprises the cannula specified herein. Furthermore, the kit preferably comprises a penetration device configured to penetrate from the coronary sinus vein into the left atrium. In particular, the penetration device is configured to penetrate through the tissue of the coronary sinus vein into the left atrium.

The penetration device may be a catheter with a needle or a wire at its distal end. The catheter may be thinner (smaller diameter) than the cannula and/or may be more flexible or bendable than the cannula. The length of the catheter may be approximately the length of the cannula, e.g. with a maximum deviation of 10 % or 5 %. The penetration device is configured to be inserted into the coronary sinus vein, to be guided intravascularly along the coronary sinus vein and then to form a hole connecting the lumen of the coronary sinus vein and the left atrium. Thus, the penetration device is configured to form a hole in the wall of the heart.

The hole may be formed with the needle at the distal end of the catheter. For example, the needle is configured such that the hole has a diameter of at most 10 French or at most 8 French or at most 6 French. Accordingly, the diameter of the needed may be at most 10 French or at most 8 French or at most 6 French. Particularly, the diameter of the hole is smaller than the outer diameter of the cannula body of the cannula.

Alternatively, when the catheter is inserted into the coronary sinus vein, the wire at the distal end can be used to burn a hole through the wall of the heart to the left atrium, for example by energizing the wire electrically, particularly by using alternating current with radiofrequency (in the following the wire is also called RF wire/tip). Also in this case, the wire and the applied electrical power may be chosen such that the diameter of the hole is at most 10 French or at most 8 French or most 6 French.

Next, the method for cannulizing a heart is specified. Particularly, the heart of a mammal, for example of a human, is cannulized with this method. “Cannulizing” is the process of inserting a cannula.

According to at least one embodiment, the method comprises a step, in which a first cannula is inserted into the coronary sinus vein. The cannula specified herein comprising the first section, the bended intermediate section and the second section may be used as the first cannula. Moreover, for the method of cannulizing a heart, the kit and/or the heart assist system specified herein might be used. Thus, all features disclosed in connection with the cannula, the kit and/or the heart assist system are also disclosed for the method and vice versa.

According to at least one embodiment, the method comprises a step performed after the step of inserting the first cannula into the coronary sinus vein, in which the first cannula is guided intravascularly along the coronary sinus vein. According to at least one embodiment, the method comprises a step performed after the step of guiding the first cannula along the coronary sinus vein in which the first cannula is inserted from the coronary sinus vein into the left atrium. After insertion into the left atrium, the first cannula, particularly the first section, protrudes into the left atrium, for example by at least 0.2 cm or at least 0.5 cm or at least 1.0 cm and/or by at most 3.0 cm or at most 2.0 cm. Particularly, after insertion, i.e. in the final position of the first cannula, the first cannula / the first section of the first cannula ends in the left atrium. Thus, after insertion into the left atrium, the first cannula is preferably not further guided into another region of the heart.

In at least one embodiment, the method for cannulizing a heart comprises:

- inserting a first cannula into the coronary sinus vein,

- afterwards, guiding the first cannula intravascularly along the coronary sinus vein,

- afterwards, inserting the first cannula from the coronary sinus vein into the left atrium.

Inserting a cannula via the coronary sinus vein into the left atrium of the heart turned out to be particularly advantageous for sucking out blood out from the left atrium. For example, when a further cannula or a cannula system is inserted into the heart, via which blood is sucked out from the left atrium, the above mentioned first cannula can be used to increase the amount of blood sucked out per time interval. However, the total suction pressure can be kept sufficient small so that the sucked out blood is not damaged. For example, the absolute value of the total suction pressure is at most 150 mmHg or at most 200 mmHg or at most 300 mmHg.

According to at least one embodiment of the method, before inserting the first cannula into the left atrium, a hole is formed connecting the left atrium with the lumen of the coronary sinus vein. Thus, the hole fluidically connects the left atrium with the lumen of the coronary sinus vein so that blood can be exchanged between the coronary sinus vein and the left atrium via the hole. The maximum diameter of the hole is, for example, at most 10 French or at most 8 French or at most 6 French. The hole may be formed with the penetration device.

According to at least one embodiment, the first cannula is inserted into the left atrium via the hole. As the outer diameter of the first cannula is preferably greater than the diameter of the hole, the tissue of the heart around the hole is stretched when guiding the first cannula through the hole so that no gap between the tissue and the first cannula is formed. According to at least one embodiment, the hole is created by puncturing with help of a needle or by burning the hole using a wire, e.g. by applying an alternating current with a radiofrequency to the wire. The hole is, for example, formed with help of the catheter comprising the needle or the wire, specified herein. For this purpose, before inserting the cannula into the body, the catheter may first be inserted into the coronary sinus vein and may be guided intravascularly along the coronary sinus. Then the needle or the wire is used to form the hole connecting the coronary sinus vein with the left atrium. The catheter may then be removed from the body, before the first cannula is inserted into the body. The catheter may be inserted into the body along the same path as it is foreseen for the first cannula.

According to at least one embodiment, before inserting the first cannula into the coronary sinus vein, the first cannula is inserted into and intravascularly guided along the vena cava, for example along the superior vena cava. Afterwards, the first cannula is inserted into the coronary sinus vein. Particularly, the first cannula is inserted from the right atrium via the coronary sinus ostium into the coronary sinus vein.

According to at least one embodiment, the first cannula is inserted jugularly, i.e. intravascularly along the jugular vein. From there, it may be guided into the superior vena cava and then into the coronary sinus vein and finally into the left atrium. It is also possible to insert the first cannula intravascularly along the subclavian vein and from there further into the superior vena cava and into the coronary sinus vein.

Alternatively, the first cannula may be inserted fem orally, i.e. intravascularly along the femoral vein, and from there guided into the inferior vena cava and then into the coronary sinus vein.

According to at least one embodiment, the first cannula is inserted into the body over a length of at least 10 cm or at least 15 cm of at least 20 cm.

An introducer may be used for introducing the first cannula. The introducer may be inserted into the lumen of the first cannula before the first cannula is inserted into the body. The introducer may, when inserted into the lumen, straighten the first cannula, particularly in the intermediate section and in the second section. The introducer may leave only a small gap or offset to the inner surface of the first cannula preventing or reducing blood flow out of the first cannula during the placement of the first cannula. The first cannula may be inserted into the body with the introducer in the lumen of the first cannula. When the first cannula is in its final position, the introducer may be removed.

A guide wire may also guide the introducer. E.g., the introducer may have a longitudinal central opening for a guide wire. The guide wire may be inserted into the body, particularly into the left atrium, along the path which is foreseen for the first cannula, but preferably before the first cannula is inserted. The guide wire may be guided through the catheter or may be introduced after the catheter has been removed. Also if no introducer is used, the first cannula may be guided along a guide wire.

According to at least one embodiment, after inserting the first cannula into the left atrium, blood is sucked out from the left atrium into a lumen of the first cannula and is guided along the lumen of the first cannula towards the proximal end of the first cannula. Particularly, the blood sucked out via the first cannula is guided out of the body. For sucking out the blood, the proximal end of the first cannula may be connected to a pump.

For sucking out the blood, the cannula body of the first cannula comprises an opening at or in the region of its distal end, which fluidically connects the left atrium with the lumen of the first cannula. For example, at least 0.5 1 blood per minute and/or at most 2 1 blood per minute are sucked out with help of the first cannula.

According to at least one embodiment, the blood sucked out with help of the first cannula is afterwards medically processed. Medical processing preferably happens outside of the body. After medical processing, the blood may be reinserted into the heart, preferably via a further cannula or a cannula system. For reinserting the blood, a pump may be used. Medical processing includes, but is not limited to: enriching with oxygen, removing of carbon dioxide, adding a drug to the blood.

Instead of medically processing the blood, it is also possible to only reinsert the blood into the heart, e.g. with help of a pump but without medical processing. In this way, the function of the heart as a natural pump may be supported. According to at least one embodiment, the method comprises a step, in which a second cannula is inserted into the left atrium via a different path than the first cannula. The second cannula may be a single lumen cannula or a double lumen cannula or a multi lumen cannula. The second cannula is, in particular, inserted into the left atrium along a path which does not run along the lumen of the coronary sinus vein. After inserting, i.e. in the final position of the second cannula, the second cannula preferably ends in the left atrium, i.e. the distal end of the second cannula ends in the left atrium.

The insertion of the second cannula into the left atrium may happen before or after the first cannula is inserted.

According to at least one embodiment, the second cannula is first inserted intravascularly into the right atrium of the heart. Afterwards, the second cannula is further inserted from the right atrium through the atrial septum into the left atrium. The second cannula may be guided through a hole in the atrial septum fluidically connecting the left atrium and the right atrium. The hole may be formed with help a catheter, similar to the one described above.

The second cannula may be inserted jugularly, then into the superior vena cava and from there into the right atrium. It is also possible to insert the second cannula intravascularly along the subclavian vein and form there further into the superior vena cava and into the coronary sinus vein.

According to at least one embodiment, a third cannula is inserted into the second cannula so that the second cannula and third cannula define a cannula system with two lumens being fluidically decoupled. The cannula system may be the cannula system described in connection with the heart assist system.

According to at least one embodiment, the third cannula is inserted into the second cannula after the second cannula has been inserted into the left atrium, i.e. has been brought in its final position. Inserting the second cannula and the third cannula one after the other is advantageous as the second cannula is more bendable or flexible if the third cannula is not yet inserted. According to at least one embodiment, the third cannula is further inserted into the left ventricle or into the aorta. For example, the third cannula is inserted, starting from the distal end of the second cannula, through the mitral valve into the left ventricle. A distal end of the third cannula may then end in the left ventricle. Alternatively, the third cannula may further be inserted through the aortic valve into the aorta and may then end in the aorta, e.g. in the ascending aorta.

According to at least one embodiment, after insertion of the second cannula and the third cannula, i.e. after the second cannula and the third cannula have reached their final positions, blood is sucked out from the left atrium into a first lumen of the cannula system and is guided along the first lumen towards a proximal end of the cannula system. For example, the proximal end of the cannula system is outside the body so that the blood is guided out of the body along the first lumen. For sucking out the blood, the cannula body of the second cannula comprises an opening at its distal end which fluidically connects the first lumen with the left atrium. By way of example, at least 2 1 blood per minute and/or at most 4.5 1 blood per minute are sucked out from the left atrium with help of the cannula system.

According to at least one embodiment, blood is guided along the second lumen of the cannula system and is injected into the left ventricle or the aorta. For injecting the blood, the third cannula comprises an opening at its distal end which fluidically connects the second lumen of the cannula system with the left ventricle or the aorta, respectively. For example, at least 3 1 blood per minute and/or at most 6 1 blood per minute is injected into the left ventricle or the aorta with help of the cannula system.

According to at least one embodiment, blood sucked out from the left atrium via the first cannula and the cannula system is afterwards inserted into the second lumen of the cannula system. For example, proximal ends of the first cannula and of the cannula system are connected to a pump outside the body. The pump is used to suck out the blood via the first cannula and the cannula system and may also be used to reinsert the blood into the second lumen of the cannula system.

According to at least one embodiment, the blood is enriched with oxygen and/or carbon dioxide is removed before inserted into the second lumen of the cannula system. For example, an oxygenator outside of the body enriches the blood with oxygen. According to at least one embodiment, the third cannula has an outer diameter that is smaller than an inner diameter of the second cannula by at least 3 French or at least 4 French or at least 5 French or at least 6 French. Additionally or alternatively, the outer diameter of the third cannula may be smaller than the inner diameter of the second cannula by at most 12 French or at most 11 French or at most 10 French or at most 9 French. The outer or inner diameter of the second cannula may be at least 21 French and/or at most 33 French. The outer or inner diameter of the third cannula may be at least 9 French and/or at most 21 French. Outer and inner diameters refer to the outer and inner diameters of the respective cannula bodies of the cannulas.

The area of the first lumen of the cannula system is defined by the difference between the outer diameter of the third cannula and the inner diameter of the second cannula. In order to guarantee a sufficient flexibility of the second and the third cannula for the insertion into the heart, the outer diameters of both cannulas should not be too large, for example at most 33 French or at most 29 French or most 27 French. Of course, the outer diameter of the third cannula has to be smaller than the inner diameter of the second cannula so that the third cannula fits into the second cannula. However, the third cannula should not be too thin in order to allow a sufficient blood flow through the lumen of the third cannula. Thus, the area of the first lumen of the cannula system is limited. As a consequence, the amount of blood which can be sucked out and guided along the first lumen of the cannula system is also limited. For example, between 2 1 and 4 1 blood per minute can be sucked out via the first lumen of the cannula system.

Using the first cannula is advantageous, because it allows to additionally suck out blood from the left atrium, for example about 1 1 per minute. In total, about 5 1 per minute can be sucked out from the left atrium, which is in accordance with the natural blood flow of the heart.

Sucking out blood via the first cannula and/or the cannula system and/or the insertion of blood via the cannula system may be done in a pulsed manner with help of the pump or in a continuous manner with help of a pump. A pulsed flow is the natural mode of transport of body fluids and may result in less damage to the body and/or to specific organs. Moreover, a cannula is specified which is configured to be used as the first cannula in the method specified.

Hereinafter, a cannula, a cannula system, a kit and a method described herein will be explained in more detail with reference to drawings on the basis of exemplary embodiments. Same reference signs indicate same elements in the individual figures. However, the size ratios involved are not necessarily to scale, individual elements may rather be illustrated with an exaggerated size for a better understanding.

Figures 1 A and IB show an exemplary embodiment of the cannula/first cannula in different views,

Figure 2 shows an exemplary embodiment of a kit comprising a cannula and a catheter,

Figure 3 shows an exemplary embodiment of the heart assist system,

Figure 4 shows a cross-sectional view of an exemplary embodiment of a cannula system with two lumens,

Figure 5 shows a further exemplary embodiment of the heart assist system,

Figures 6 to 11 show different positions in a method for cannulizing a heart.

Figure 1A shows an exemplary embodiment of the cannula 01, also referred to as first cannula 01, in a side view. Figure IB shows a cross sectional view of the cannula 01, wherein the cut plane AA’ runs through a distal end DOI of a cannula body O1B of the cannula 01.

The cannula 01 is in a base state, i.e. no external forces are applied to the cannula 01. The cannula 01 or the cannula body O1B is bendable or flexible, respectively. The cannula 01 comprises a cannula body 01B, which is formed as a tube. A sidewall of the cannula body 01B may comprise a plastic or silicone. The sidewall may comprise an internal metal scaffold or framework. The sidewall is hashed in Figure IB. The length of the cannula 01 or of the cannula body 01B may be between 20 cm and 80 cm, inclusive.

The cannula body O1B comprises, in the base state of the cannula 01, a first section SI, a second section S2 and a pre-bended intermediate section K connecting the first section SI and the second section S2. A bending angle of the intermediate section K is, e.g., 90°. The first section SI extends from a distal end DOI of the cannula body O1B to the intermediate section K and adjoins the intermediate section K. The second section S2 adjoins the intermediate section K and extends from the intermediate section K in direction to the proximal end PO1 of the cannula 01.

A length of the first section SI is, for example, between 1 cm and 2 cm, inclusive. The intermediate section K is shorter than the first section SI. The second section S2 has, for example, a length between 5 cm and 10 cm, inclusive. Between the second section S2 and the proximal end PO1, a third section S3 of the cannula 01 is arranged. The borders between the different sections are indicated by dashed lines, respectively.

In the base state of the cannula 01, the second section S2 has a curvature. A curvature radius of the second section S2 is, for example, between 5 cm and 50 cm, inclusive. The curvature radius of the second section S2 is, preferably, constant over a large part of the length of the second section S2 or varies by at most 10% around an average curvature radius.

Moreover, in the base state, the first section SI is straight. Also the third section S3 is straight. The length of the third section S3 is, e.g., greater than 10 cm.

The cannula 01 is a single lumen cannula comprising only one lumen LI, along which a fluid, particularly blood, can be guided (see also Figure IB). An inner diameter of the cannula body O1B, i.e. the diameter of the lumen LI, is, for example between 10 French and 12 French, inclusive. The outer diameter may be between 2 French and 4 French larger than the inner diameter.

In the region of the distal end DOI of the cannula body O1B, the cannula 01 comprises a diameter variable arrangement DVA in the form of a cage arrangement with a plurality of wires. The wires may be made of a super elastic material, e.g. stainless steel, and may each have a thickness between 0.25 mm and 0.75 mm, inclusive. The cage arrangement DVA is in an expanded state, in which its diameter is larger than the diameter of the sections SI, S2 S3 of the cannula body O1B. The cage arrangement DVA projects beyond the distal end DOI of the cannula body O1B by, e.g., 1 cm. The cage arrangement DVA further comprises a membrane M, which is also in an expanded state. The membrane M covers a proximal portion of the diameter variable arrangement DVA. An edge of the membrane M defines a distal opening that faces distally relative to the first section S 1. The membrane M has a proximal opening facing proximally with respect to the first section SI. The diameter of the proximal opening is smaller than the one of the distal opening. The proximal opening radially surrounds the first section SI. A volume defined by the membrane M is fluidically coupled to the lumen LI of the cannula 01 via an opening at the distal end of the first section SI. The diameter of the opening of the first section SI at the distal end of the first section SI is, e.g., the same as the diameter of the lumen LI (see also Figure IB). The membrane M is, e.g., made of PTFE and has, e.g., a thickness between 10 pm and 50 pm, inclusive.

The diameter variable arrangement DVA and/or the membrane M are optional. The cannula 01 could also be used for the insertion into the left atrium via the coronary sinus vein without these two elements.

The usage of single end-opening (i.e. without any side-holes) in the cannula body may result in high flow rates and/or less wall shear stress and/or less shear rates and/or less turbulences and/or less recirculation and/or more homogeneous velocity profile of the blood transported within the first cannula 01. However, alternatively the first cannula 01 may have a distal tip having side-holes in combination with a cage arrangement and/or membrane or without a cage arrangement

Figure 2 shows an exemplary embodiment of the kit comprising the cannula 01 of figure 1 and a penetration device PD in the form of a catheter. The catheter PD comprises a needle PD1 or a wire PD1 at its distal and. The catheter PD may be inserted into a body before the cannula 01 is inserted into the body. The needle PD1 or the wire PD1 are configured for producing a hole connecting the lumen of the coronary sinus vein of a heart with the left atrium of the heart. For example, the catheter PD has a smaller outer diameter than the cannula body O1B and/or is more bendable or flexible than the cannula 01. The length of the catheter PD may be approximately the length of the cannula 01. The diameter of the needle PD1 may be 5 French. The needle PD1 or wire PD1 may be configured to produce a hole with a diameter of about 5 French in the wall of the heart. Figure 3 shows a heart assist system 100 comprising the cannula 01 of figure 1 and a cannula system S23. The cannula system S23 comprises a second cannula 02 and a third cannula 03, both of them being a single lumen cannula. The third cannula 03 is thinner than the second cannula 02 and is inserted into the second cannula 02. By way of example, an outer diameter of the cannula body of the third cannula 03 is smaller by 8 French than the inner diameter of the cannula body of the second cannula 02 (see also Figure 4).

The second cannula 02 and the third cannula 03 of the cannula system S23 define two lumens L2, L3, wherein a first lumen L2 is defined between an outer surface of the third cannula 03 and an inner surface of the second cannula 02. A second lumen L3 is defined by the lumen of the third cannula 03 (see also figure 4).

The proximal ends of the first cannula 01 and of the cannula system S23 are connected to a pump P. The pump P can be a diaphragm pump with two ports (or just one port plus additional external valves and Y-connector) or another pump (centrifugal pump, roller pump, etc.).

In figure 3, the first cannula 01 and the cannula system S23 are inserted into a heart H of a body, particularly a human body. The heart H is viewed from the backside. The heart H comprises the left ventricle LV, the right ventricle RV, the left atrium LA and the right atrium RA. The inferior vena cava IVC and the superior vena cava SVC are connected to the right atrium RA. The right atrium RA is connected to the right ventricle RV via the tricuspid valve TV. The right ventricle RV is connected to a pulmonary artery PA. The left atrium LA is connected to a pulmonary vein PV. The left atrium LA and the left ventricle LV are connected via the mitral valve MV. Moreover, the left ventricle LV is connected to the aorta AO. The left atrium LA and the right atrium RA are separated from each other by the atrial septum AS.

The cannula / first cannula 01 is inserted into the heart H. In particular, the first cannula 01 is guided intravascularly along the superior vena cava SVC, from there it is inserted into the coronary sinus vein CSV, is guided intravascularly along the coronary sinus vein CSV and is inserted from the coronary sinus vein CSV into the left atrium LA of the heart H, where the first cannula 01 ends. Instead of guiding through the superior vena cava SVC, the first cannula 01 may also be guided intravascularly along the inferior vena cava IVC and from there being inserted into the coronary sinus vein CSV. The first cannula 01 is inserted into the heart H in such a way that the second section S2 of the first cannula 01 lies in and runs intravascularly along the coronary sinus vein CSV. Particularly, the curvature of the second section S2 in the base state is adapted to the curvature of the coronary sinus vein CSV so that the second section S2 of the first cannula 01 does not induce too much force or stress or pressure onto the coronary sinus vein CSV. The length of the second section is, e.g., the length of the coronary sinus vein ± 20 %. The intermediate section K of the first cannula 01 lies in a region directly opposing the left atrium LA, is sharply bended and thus allows the first section SI to project into the left atrium LA. For example, the first section SI projects into the left atrium LA by at least 0.2 cm and at most 2 cm.

The cannula system S23 is inserted into the heart H and is guided intravascularly along the superior vena cava SVC into the right atrium RA. From the right atrium RA, the cannula system S23 is guided through a hole in the atrial septum AS into the left atrium LA. The second cannula 02 ends in the left atrium LA, i.e. its distal end is in the left atrium LA. The third cannula 03 runs inside the second cannula 02, i.e. in the lumen of the second cannula 02, along the entire length of the second cannula 02 and projects beyond the distal end of the second cannula P2. From the distal end of the second cannula 02, the third cannula 03 further runs inside the left atrium through the mitral valve MV into the left ventricle LV. The third cannula 03 might end in the left ventricle LV, i.e. has its distal end in the left ventricle LV. In the present case, however, the third cannula 03 is further inserted through the aortic valve into the aorta AO and ends in the aorta AO, e.g. in the ascending aorta AO.

The heart assist system 100 of figure 3 might be operated as follows: blood is sucked out from the left atrium LA via the first lumen L2 of the cannula system S23 (see also figure 4). The under pressure necessary for this step is provided by the pump P at the distal end of the cannula system S23. For example, between 2 1 blood per minute and 4 1 blood per minute are sucked out from the left atrium LA via the cannula system S23. The blood is guided along the first lumen L2 of the cannula system S23 to the proximal end of the cannula system S23.

As the blood flow through the first lumen L2 of the cannula system S23 is limited by the area of the first lumen L2 and the maximum acceptable suction pressure, the first cannula 01 is used to support the sucking out of blood from the left atrium LA. Blood in the left atrium LA is sucked out via the first cannula 01, is guided along the lumen LI of the first cannula 01 to the proximal end of the first cannula 01. For example, about 1 1 blood per minute is sucked out via the first cannula 01.

The blood guided along the lumen LI of the first cannula 01 and along the first lumen L2 of the cannula system S23 is, e.g., guided out of the body. It can then be reinserted into the body with help of the pump P, which reinserts the sucked out blood into the second lumen L3 of the cannula system S23. The blood is then guided along the second lumen L3 of the cannula system S23 to the distal end of the third cannula 03 and is there inserted into the aorta AO. In this way, the function of the heart as a pump can be supported by the pump P outside of the body.

Figure 4 shows the cannula system S23 in a cross-sectional view with the cut plane BB’ shown in figure 3. It can be seen that the third cannula 03 is inserted into the second cannula 02 so that the first lumen L2 is defined between the outer surface of the third cannula 03 and the inner surface of the second cannula 02. The lumen of the third cannula 03 defines the second lumen L3 of the cannula system S23.

Figure 5 shows a second exemplary embodiment of the heart assist system 100, wherein the first cannula 01 and the cannula system S23 are inserted into the heart H of a body as shown in figure 3. In difference to figure 3, the heart assist system 100 comprises an oxygenator OXY besides the pump P also located outside of the body. Blood, sucked out with help of the pump P, is injected into the oxygenator OXY, is enriched with oxygen or carbon dioxide is removed, and is then inserted into the second lumen L3 of the cannula system S23 through which it is guided into the aorta AO. Additionally or instead of enriching with oxygen or removing carbon dioxide, the blood could also be enriched with a drug outside of the body.

Figure 6 shows a first position of an exemplary embodiment for cannulizing a heart H. In this position, a tube PT, e.g. a plastic tube, is inserted intravascularly, through the internal jugular vein IJV and the superior vena cava SVC into the heart H. In the region of its distal end, the tube PT comprises a bended section, configured such that an opening of the tube PT at its distal end faces the opening (coronary sinus ostium) to the lumen of the coronary sinus vein CSV. The distal end of the tube PT may be moveable, e.g. with help of a wire. During insertion of the tube PT, the tube PT may be substantially straight. After insertion, by operating the wire, the distal end can be bended so that the bended section is formed.

Figure 7 shows a second position in the method, in which a guide wire GW is guided through the lumen of the tube PT. The guide wire GW passes the bended region of the tube PT, is guided into the lumen of the coronary sinus vein CSV, is guided intravascularly along the coronary sinus vein CSV and is inserted from the coronary sinus vein CSV into the left atrium LA via a hole connecting the lumen of the coronary sinus vein CSV and the left atrium LA.

Before inserting the guide wire GW, a catheter, for example the catheter of figure 2, may be used to form the hole connecting the lumen of the coronary sinus vein CSV and the left atrium LA. The catheter may be guided inside the tube PT, then intravascularly along the coronary sinus vein CSV to a region of the coronary sinus vein CSV directly opposing to the left atrium LA. Then, the needle can be used to puncture a hole connecting the left atrium LA and the lumen of the coronary sinus vein CSV or an alternating current may be applied to a wire of the catheter so that the hole is burned into the wall of the heart H. For example, the diameter of the hole is 5 French. Accordingly, the diameter of the needle may be 5 French, as well.

Figure 8 shows a third position in the method. An introducer IT is inserted into the lumen LI of the first cannula 01 of figure 1. The introducer IT may reach from the distal end DOI to the proximal end POL Particularly, the introducer IT stretches the cannula 01 so that the bending or curvature of the intermediate section K and the second section S2 at least partially vanishes.

The introducer IT also stretches the diameter variable arrangement DVA so that the diameter variable arrangement DVA as well as the membrane M are in their non-extended states, in which the diameter is smaller, e.g. a factor 10 smaller, than in the extended state.

Insertion of the introducer IT into the first cannula 01 is preferably performed outside of the body, i.e. before the first cannula 01 is inserted into the body. For insertion, the introducer IT may be locked or clamped in a fixed position relative to the cannula 01 with help of a releasable locking mechanism. Figure 9 shows a fourth position in the method. The first cannula 01 is inserted into the heart H. The first cannula 01 is inserted, e.g., with the introducer IT in its lumen LI. The introducer IT may also comprise a lumen or central opening so that for insertion of the first cannula 01 the lumen / central opening of the introducer IT may be put over the guide wire GW. The guide wire GW can then be used to guide the first cannula 01 together with the introducer IT along the same path along the guide wire GW runs. Particularly, the first cannula 01 is guided intravascularly along the coronary sinus vein CSV and from there into the left atrium LA.

After finalizing the insertion of the first cannula 01, the introducer IT may be removed. This may cause the variable diameter arrangement DVA to automatically expand (the optional diameter variable arrangement is not shown in figures 3, 5 and 9 to 11 for reasons of clarity of the illustrations).

Figure 10 shows a fifth position in the method. A second cannula 02 is inserted into the body, is thereby guided intravascularly along the internal jugular vein IJV, along the superior vena cava SVC into the right atrium RA. From the right atrium RA, the second cannula 02 is guided through a hole in the atrial septum AS into the left atrium LA. The second cannula 02 ends in the left atrium LA. The hole in the atrial septum AS may have been produced before with help of a catheter.

Figure 11 shows a sixth position of the method, in which a third cannula 03 is guided through the lumen of the second cannula 02 along the same path as the second cannula 02. Starting from the distal end of the second cannula 02, the third cannula 03 is further guided through the mitral valve into the left ventricle LV. There the third cannula 03 might end. In the present example, the third cannula 03 is further inserted into the aorta through the aortic valve and ends in the aorta AO.

The second cannula 02 and the third cannula 03 may be inserted into the heart H using a respective catheter and/or a respective guide wire and/or a respective introducer. The proximal end of the first cannula 01 and the cannula system S23 may then be connected to a pump and/or an oxygenator and a blood flow may be started, e.g. as explained in connection with figures 3 and 5.

After a treatment of the heart H, the cannulas 01, 02, 03 may be removed again. The hole in the wall of the heart H used for inserting the first cannula 01 may be closed with an occluder.

In difference to what is shown in figures 3, 5 and 11, blood might be sucked out from the left atrium LA only via the first cannula 01. Moreover, instead of using a cannula system S23 with two lumens, it is also possible to guide a single lumen cannula via the atrial septum AS into the left atrium LA and to insert or suck out blood via this single lumen cannula while at the same time blood is sucked out via the first cannula 01.

In all embodiments one of the following methods may be used to bring or guide a guide wire and/or a catheter around or along the acute angle within the left ventricle LV. At least one snare may be used to catch the catheter and/or the guide wire in the left ventricle LV. The methods may be performed independent whether there is jugular access or a femoral access or another access for the catheter and/or the guide wire.

Variant A (catching the catheter with the snare):

1) Introducing a catheter through the right atrium RA, the atrial septum AS (a puncturing step may be performed earlier or using the catheter, e.g. using a needle and/or RF (radio frequency) tip/wire within the catheter). The catheter may be introduced further through the hole (puncture) in the atrial septum AS through left atrium LA, through mitral valve MV into the left ventricle LV.

2) Introducing a snare from descending aorta AO through aortic valve AV into left ventricle LV. This step may be performed also before step 1.

3) Catching the catheter in the left ventricle LV using the snare.

4) Pulling the snare and the distal end of the catheter therewith to the aorta AO.

5) Introducing a guide wire through the catheter.

6) Forwarding the guide wire out of the distal end of the catheter. Slight loosening of the snare may be optionally performed thereby.

7) As the guide wire is already within the snare, pull back the snare to a region in which only the guide wire is located but not the catheter. 8) Fix the guide wire using the snare, e.g. contract the snare and/or tighten the snare.

9) Optional, externalizing for instance the distal end of the guide wire out of the body. This step is optionally, because the proximal end of the snare is already outside of the body.

10) Remove catheter, e.g. pull back the catheter.

11) Introduce cannula using the guide wire, e.g. pushing the cannula along and/or over the guide wire until it is on its final place.

Variant B (catching the guide wire with the snare):

1) Introducing a catheter through the right atrium RA, through the atrial septum AS (a puncturing step may be performed earlier or through catheter, use needle and/or RF (radio frequency) tip/wire). Introducing the catheter further through left atrium LA, mitral valve MV into the left ventricle LV.

2) Introducing a guide wire through the catheter until the distal end of the guide wire comes out of the distal end of the catheter within the left ventricle LV. The RF wire may be used also as a guide wire.

3) Introducing a snare from descending aorta AO through aortic valve AV into left ventricle LV. This step may be performed before step 1 and/or before step 2.

3) Catching the distal end of the guide wire in the left ventricle LV using the snare.

4) Fixation of the guide wire using the snare.

5) Pulling the snare and the distal end of the guide wire therewith to the aorta AO.

6) Optional, externalizing guide wire by pulling it out of the body using the snare. This step is optional as the snare is already outside of the body from where it has been introduced.

7) Remove catheter, e.g. by pulling it back along the guide wire.

8) Introduce cannula over/along the guide wire until it is on place.

The following method may also be used in all corresponding embodiments for introducing a cannula jugularly transseptally:

1) Introduce a first snare into an internal jugular vein IJV, for instance into the right jugular vein RJV or into the left jugular vein LJV.

2) Advancing the first snare to inferior vena cava IVC.

3) Introducing a catheter into a common femoral vein CFV (left or right).

4) Advancing the catheter through the first snare into an inferior vena cava IVC.

5) Advancing the catheter through the first snare into the vena cava VC in an antegrade fashion. 6) Advancing the catheter through the first snare into the right atrium RA in an antegrade fashion.

7) Advancing the catheter through the first snare and from the right atrium RA transseptally through the atrial septum into the left atrium LA in an antegrade fashion. Puncturing of atrial septum may have been performed earlier. Alternatively, the catheter is used to puncture the atrial septum, for instance using a needle or using a RF (radio frequency) wire/tip which is introduced trough the catheter.

8) Advancing the catheter through the first snare and advancing the catheter across the mitral valve MV and into the left ventricular outflow tract, e.g. the left ventricle LV.

9) Advancing a second snare in the ascending aorta AO catching and snaring a distal portion of the catheter (Variant A) within the left ventricle LV. The second snare may optionally be introduced through an artery, which may include, but is not limited to, a radial artery, a brachial artery, an axillary artery, a subclavian artery, a carotid artery, or common femoral artery, and advanced retrograde into the aorta AO and into the left ventricle LV. The second snare may be already introduced before the catheter is introduced. Alternatively, a guide wire may be inserted into the catheter until a distal end of the guide wire comes out of a distal opening of the catheter. This distal end of the guide wire is then caught and snared within the left ventricle (Variant B)

10) Pulling the catheter (Variant A) or the guide wire (Variant B) into the aorta AO in an antegrade fashion using the second snare.

11) In variant A, advancing a guide wire through the catheter and through the first snare in antegrade fashion to the ascending aorta AO and through the second snare. Snaring the distal end of the guide wire in variant A but not the catheter.

12) In both variants A and B remove the catheter with the guide wire remaining in the heart H and through the first snare after the catheter is removed.

13) Externalizing a proximal portion of the guide wire from the femoral vein, through inferior vena cava, through superior vena cava SVC, into the internal jugular vein IJV and then out of the internal jugular vein IJV using the first snare, for instance left jugular vein LJV or right jugular vein RJV. In some embodiments the snare may externalize a different portion of the guide wire, for instance an intermediate portion.

14) Advancing a cannula using the guide wire and/or along and/or over the guide wire from the internal jugular vein IJV. The cannula may be any of the cannulas described in this specification or known in the art. Especially, an outer cannula may be advanced over the guide wire from the internal jugular vein IJV. An inner cannula may optionally be advanced through a port proximal of the distal end of the outer cannula. The inner cannula and the outer cannula may be positioned as described in this description, or if a single multi-lumen cannula is used, it may be positioned in a similar manner.

15) Optionally, a distal portion of the guide wire may be externalized out of the body through the artery. This step is optional because the second snare is already externalized and may form a secure anchor for the distal portion of the guide wire.

Subclavian arteries/veins or other arteries/veins may be used for introducing the snare(s) because the snares require smaller diameters, e.g. less than 10 French (1 French equal to 1/3 mm (millimeter)) or less than 8 French, e.g. more than 3 French, compared to the diameters of the cannula(s).

In the following details of a method for puncturing transseptally through the atrial septum AS of the heart H are provided. However, other methods may be used as well, for instance using a needle.

A catheter and/or a wire may be used which has a distal tip which can be heated, for instance using RF (radio frequency) energy, alternating current (ac), direct current (de) etc. Thus, e.g. a hole may be burned into the septum, e.g. the atrial septum AS, during puncturing, for instance using temperatures above 100 °C (degrees Celsius) or above 200 °C, less than 1000 °C for instance.

The RF (radio frequency) may be in the range of 100 kHz (kilohertz) to 1 MHz (Megahertz) or in the range of 300 kHz to 600 kHz, for instance around 500 MHz, i.e. in the range of 450 kHz to 550 kHz, e.g. 468 kHz.

The power of the radio frequency energy may have a maximum of 50 Watt. A power range of 5 W (watt) to 100 W may be used, for instance a range of 10 W to 50 W.

A sinus current/voltage may be used for the RF. The sinus current/voltage may be continuous. Alternatively, a pulsed sinus current/voltage may be used for the RF.

All parameters or some of the parameters of the RF equipment may be adjustable by an operator who performs the puncturing, for instance dependent on the specifics of the septum, e.g. normal septum, fibrotic septum, aneurysmal septum, etc. Preferably, the power may be adjustable.

A solution of Baylis Medical (may be a trademark), Montreal, Canada may be used, for instance NRG® trans-septal needle or Supra Cross® RF Wire technology. RF generator of type RFP-100A or a further development of this model may be used. This RF generator uses for example a frequency of 468 kHz (kilohertz).

A single puncture of the septum may be performed from a jugular access or from a femoral access or from another appropriate access using the RF energy. Smaller angles may be possible for the catheter if for instance compared with a needle.

Alternatively, the RF method may be used also if two separate punctures are made in the septum. However, usage of needles is possible as well. One of the punctures using the RF method may be made through left jugular vein LJV and the other puncture of the atrial septum AS may be made through the right jugular vein RJV.

It is possible to introduce both guide wires first through the atrial septum AS. Preferably, separate holes are used for each of the guide wires. Guide wire(s) may be used which include an RF tip. Alternatively, the wire(s) having the RF tip may be pulled back and a further wire may be introduced through the catheter.

Only after both guide wires are in place, both cannulas may be introduced using a respective one of the guide wires.

Alternatively, the first puncture may be performed using RF energy or a needle. Thereafter, the first cannula for blood transfer is inserted using the first guide wire. After insertion of the first cannula, the second puncture may be made. A second guide wire or the first guide wire may be used to introduce the second cannula.

Puncturing of the atrial septum may be assisted by at least one medical imaging method, preferably by at least two medical imaging methods. US (ultra-sonic) echo imaging may be used to visualize the movement of heart H and the location of the valves of heart H. No dangerous radiation may result from ultra-sonic imaging. An ultra-sonic transmitter may be introduced for instance via the esophagus, e.g. trans esophagus echo (TEE) may be used.

X-ray radiation preferably in combination with fluorescence (fluoroscopy), may be used in order to visualize the location of catheters (comprising for instance at least one X-ray marker, or the devises are usually radiopaque) and/or the location of guide wire(s), snares etc.

Thus, transseptal puncturing or puncturing of other tissue may be guided by TEE and by fluoroscopy or by other imaging methods. At least two different image generating methods may be used.

In all embodiments mentioned above, it is also possible to use a soft guide wire and a stiffer guide wire which does not bend so easy if compared with the soft guide wire. The following steps may be performed, preferably in combination with snaring:

1) Introduce a soft guide wire.

2) Introduce catheter using the soft wire as a guide.

3) Optionally, remove soft wire, for instance by pulling back the soft wire out of the catheter.

4) Introduce stiffer guide wire into the catheter, e.g. there may be a change of wire from soft wire to the stiffer wire.

The catheter may be removed, e.g. pulled back. Thereafter, the stiffer wire may be used to introduce a cannula or cannulas.

The RF puncturing or another thermal puncturing may be used to puncture a hole from coronary sinus vein through wall of left atrium. Thus, the arc that is formed by eh coronary sinus vein does not form a hindrance during puncturing because the thermal tip, for instance the RF tip may be guided to the wall and is thereafter activated in order to burn the hole which is later used to introduce the cannula from the coronary sinus vein CSV into the left atrium LA. At least two different image generating methods may be used to puncture the wall of the left atrium from the coronary sinus vein CSV, e.g. the puncturing may be guided by TEE and by fluoroscopy or by other imaging methods. Thus, RF puncturing may be used at least once for puncturing through the coronary sinus vein CSV. The atrial septum AS or another septum of the heart H may also be punctured using RF energy or other thermal methods. However, the atrial septum AS may also be punctured using a needle, for instance if a femoral access is used.

The invention described herein is not limited by the description in conjunction with the exemplary embodiments. Rather, the invention comprises any new feature as well as any combination of features, particularly including any combination of features in the patent claims, even if said feature or said combination per se is not explicitly stated in the patent claims or exemplary embodiments.

Reference sign list:

01 cannula/ first cannula

02 second cannula

03 third cannula

S23 cannula system

LI lumen of cannula 01

L2 first lumen of cannula system S23

L3 second lumen of cannula system S23

O1B cannula body of the cannula 01

51 first section of cannula 01

52 second section of cannula 01

53 third section of cannula 01

K intermediate section of cannula 01

P pump

OXY oxygenator

DOI distal end of cannula 01

PO1 proximal end of cannula 01

IT introducer

AS atrial septum

AO aorta

CSV coronary sinus vein

SVC superior vena cava

I VC inferior vena cava

RA right atrium

LA left atrium

RV right ventricle

LV left ventricle

PA pulmonary artery

PV pulmonary vein

IJV internal jugular vein

TV tricuspid valve

MV mitral valve

PT tube W wire

GW guide wire

PD penetration device

PD1 needle or wire of the penetration device DVA diameter variable arrangement

Claims

1. Cannula (01) for insertion into the left atrium (LA) of a heart (H) via the coronary sinus vein (CSV), wherein

- the cannula (01) comprises a cannula body (O1B), which, in a base state of the cannula (01), has a first section (SI), a second section (S2) and a bended intermediate section (K) connecting the first section (SI) and the second section (S2),

- the first section (SI) extends from a distal end (DOI) of the cannula body (O1B) to the intermediate section (K),

- the second section (S2) extends from the intermediate section (K) in the direction of a proximal end (PO1) of the cannula (01),

- the cannula (01) is configured such that, when inserted as intended , the second section (S2) is located in and extends along the coronary sinus vein (CSV) and the first section (SI) projects into and ends in the left atrium (LA) of the heart (H),

- in the base state, a bending angle of the intermediate section (K) is at least 45° and at most 135°.

2. Cannula (01) according to claim 1, wherein

- in the base state of the cannula (01), the second section (S2) is curved,

- the curvature of the second section (S2) is adapted to the curvature of the coronary sinus vein (CSV).

3. Cannula (01) according to claim 2, wherein

- the second section (S2) directly adjoins the intermediate section (K).

4. Cannula (01) according to any of the claims 2 or 3, wherein

- in the base state of the cannula (01), a curvature radius of the second section (S2) is greater than a bending radius of the intermediate section (K).

5. Cannula (01) according to any of the claims 2 to 4, wherein

- in the base state of the cannula (01), the curvature radius of the second section (S2) is at least 5 cm and at most 50 cm.

6. Cannula (01) according to any of the preceding claims, wherein

39 - a length of the intermediate section (K) is smaller than the length of the first section (SI).

7. Cannula (01) according to any of the preceding claims, wherein

- the length of the first section (SI) is at least 1.0 cm and at most 2.5 cm,

- the length of the second section (S2) is at least 5 cm,

- in the base sate, the bending angle of the intermediate section (K) is at least 80° and at most 100°.

8. Cannula (01) according to any of the preceding claims, wherein

- the cannula (01) is a single lumen cannula,

- an inner diameter of the cannula body (O1B) is at least 8 Fr and at most 14 Fr.

9. Cannula (01) according to any of the preceding claims, wherein in the region of the distal end (DOI), the cannula (01) comprises a diameter variable arrangement (DVA), which is configured to increase its diameter in order to secure the first section (SI) in the left atrium (LA).

10. Heart assist system (100) comprising

- the cannula (01) according to any of the preceding claims,

- a cannula system (23) with two lumen (L2, L3).

11. Heart assist system (100) according to claim 10, wherein

- the cannula system (S23) comprises a second cannula (02) and a third cannula (03), wherein

- the third cannula (03) is adapted to be guided into the second cannula (02), whereby a first lumen (L2) is defined between an outer surface of the third cannula (03) and an inner surface of the second cannula (02),

- a lumen of the third cannula (03) defines a second lumen (L3),

- the first (L2) and the second (L3) lumen of the cannula system (S23) are fluidically decoupled when the third cannula (03) is inserted into the second cannula (02).

12. Heart assist system (100) according to claim 10 or 11, further comprising

- a pump (P) configured to be connected to the proximal end (PO1) of the cannula (01) and to suck out blood from a heart (H) via the cannula (01).

40

13. Kit comprising

- a cannula (01) according to any of the claims 1 to 9,

- a penetration device (PD) configured to penetrate from the coronary sinus vein (CSV) into the left atrium (LA).

14. Method for cannulizing a heart (H), comprising

- inserting a first cannula (01) into the coronary sinus vein (CSV),

- afterwards, guiding the first cannula (01) intravascularly along the coronary sinus vein (CSV),

- afterwards, inserting the first cannula (01) from the coronary sinus vein (CSV) into the left atrium (LA).

15. Method according to claim 14, wherein

- before inserting the first cannula (01) into the left atrium (LA), a hole is formed connecting the left atrium (LA) with the lumen of the coronary sinus vein (CSV),

- the first cannula (01) is inserted into the left atrium (LA) via the hole.

16. Method according to claim 15, wherein

- the hole is created by puncturing with help of a needle or by burning the hole using a wire.

17. Method according to any of the claims 14 to 16, wherein

- after inserting the first cannula (01) into the left atrium (LA), blood is sucked out from the left atrium (LA) into a lumen (LI) of the first cannula (01) and is guided along the lumen (LI) of the first cannula (01) towards a proximal end (PO1) of the first cannula (01).

18. Method according to claim 17, wherein

- the blood sucked out with help of the first cannula (01) is afterwards medically processed.

19. Method according to any of the claims 14 to 18, wherein

- a second cannula (02) is inserted into the left atrium (LA) via a different path than the first cannula (01).

20. Method according to claim 19, wherein

41 - the second cannula (02) is first inserted intravascularly into the right atrium (RA) of the heart (H),

- afterwards, the second cannula (02) is further inserted from the right atrium (RA) through the atrial septum (AS) into the left atrium (LA).

21. Method according to claim 19 or 20, wherein

- a third cannula (03) is inserted into the second cannula (02) so that the second cannula (02) and the third cannula (03) define a cannula system (S23) with two lumens (L2, L3) fluidically decoupled.

22. Method according to claim 21, wherein

- the third cannula (03) is inserted into the second cannula (02) after the second cannula (02) is inserted into the left atrium (LA).

23. Method according to claim 22, wherein

- the third cannula (03) is further inserted into the left ventricle (LV) or into the aorta (AO).

24. Method according to claim 23, wherein, after insertion of the second cannula (02) and the third cannula (03),

- blood is sucked out from the left atrium (LA) into a first lumen (L2) of the cannula system (S23) and is guided along the first lumen (L2) towards a proximal end of the cannula system (S23),

- blood is guided along a second lumen (L3) of the cannula system (S23) and is injected into the left ventricle (LV) or the aorta (AO).

25. Method according to claims 17 and 24, wherein

- blood sucked out from the left atrium via the first cannula (01) and the cannula system (S23) is afterwards inserted into the second lumen (L3) of the cannula system (S23).

26. Method according to claim 25, wherein

- the blood is enriched with oxygen and/or carbon dioxide is removed before inserted into the second lumen (L3) of the cannula system.

27. Method according to claim 21 or any of claims 22 to 26 in its dependency of claim 21, wherein

- the third cannula (03) has an outer diameter that is smaller than an inner diameter of the second cannula (03) by at least 3 Fr and at most 12 Fr.

28. Cannula (01) configured to be used as the first cannula (01) in the method according to any of the claims 14 to 27.