Device for treatment of mitral insufficiency

(54)

Assignee

INVENTOR

TERMINAL DESIGNATION (56) (57)

Jan Otto Solem, Nordmannavägen 20 237 31 Bjärred SE

Per Ola Kimblad, Saturnusgatan 9 224 57 Lund SE

Jan Otto Solem, Bjärred SE, Per Ola Kimblad, Lund SE

AWAPATENT AB

Apparatus for treating lack of closure of the mitral valve apparatus

CALLED PUBLICATIONS: - - SUMMARY:

An apparatus for treating mitral ring dilation comprises an elongated body (8) having two states. In a first of these conditions, the elongated body (8) is insertable into the large cardiac vein (5) and has a shape which adapts to the shape of the large cardiac vein (5). When the elongated body (8) is placed in the large cardiac vein (5), it is transferable to its second state, in which it adopts a reduced radius of curvature, thereby reducing the radius of curvature of the large heart vein (5) and the radius of curvature of the mitral ring (6) and perimeter. .

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The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

514 718

The present invention relates generally to a device for treating defective closure of the mitral valve apparatus and more specifically to treat dilation of the mitral ring.

Lack of closure ability of the mitral valve apparatus can have several causes, for example, ischemic disease, degenerative disease of the mitral organ, rheumatic fever, endocarditis, congenital heart disease, and cardiomyopathy. The four main parts of the mitral valve apparatus are the mitral valve, the two sail flaps, the tendon strings and the papillary muscles. Some or all of these, in various combinations, can be damaged and cause a lack of closure. Ring dilation is an important part of the pathology of lack of closure capability of the mitral valve apparatus, regardless of its cause. In addition, many patients initially have a lack of closure capability of the mitral valve apparatus, or only because of a posterior ring dilation, since the ring of the anterior flap does not dilate because it is attached to the fibrous body in the base of the heart.

Studies of the natural course of failure of the mitral valve apparatus have shown that completely symptom-free patients with severe defects in the mitral valve's capability usually develop this into a severe disability within five years. Currently, the treatment consists of either replacement or repair of the mitral valve apparatus, both of which require open heart surgery. Replacement can be carried out with either mechanical or biological flap devices.

The mechanical flap apparatus carries the risk of thromboembolism and requires treatment with coagulation inhibitors (P; 2,000-1 0 in 1025.OC).

514 718 part, with all its potential risks, while biological prostheses have limited durability. Another risk of replacement is the risk of endocarditis. These risks and other flap-related complications are greatly reduced with the help of flap closure.

It is theoretically possible to repair the mitral valve apparatus if a substantially normal front sail flap is available. The basic four techniques in repair include the use of an annular plastic ring, square segmental resection of the inflamed posterior flap, truncation of extended tendon strands, and the relocation of the posterior flap to the anterior sail flap.

Ring-shaped plastic rings are required to achieve a durable reduction in ring dilation. All commonly occurring rings are sewn along the posterior mitral seal flap near the mitral annulus in the left atrium. The Duran ring completely surrounds the flap apparatus, while the others are open to the front sail flap. The ring can either be rigid, like the original Carpentier ring, or be flexible but not elastic like the Duran ring or the Cosgrove-Edwards ring.

Effective treatment of the lack of closure capability of the mitral valve apparatus currently requires open heart surgery using total cardiopulmonary bypass, aortic cross-clamping and heartbeat blockage.

This is particularly risky for some patient groups. Particularly elderly patients, patients with poor left ventricular function, kidney disease, severe aortic atherosclerosis, previous cardiac surgery or other accompanying diseases would most likely feel the best of less invasive procedures, although the repair is not complete. The current trend toward less invasive coronary artery disease, without cardiopulmonary bypass, as well as PTCA will also require a trend toward less invasive methods of repairing the often-associated lack of closure capability of the mitral valve apparatus.

It is therefore an object of the present invention to provide a device for treating a lack of closure capability of the mitral valve apparatus, without the need for cardiopulmonary bypass and opening of the chest and heart.

This and other objects are achieved with a device according to the appended claim 1.

According to the present invention, a device for treating a lack of closure of the mitral ring comprises an elongated body having dimensions such that it is insertable into the large cardiac veins and having two states, namely a first state, in which the elongated body has a shape which is adaptable to the shape of large heart veins, and a second condition, to which the elongated body is transmissible from the first state to assume a reduced radius of curvature, thereby reducing the radius of curvature of the large heart vein, as well as the circumference of the mitral valve, when the elongated body is placed, in the large heart vein.

Preferably, means are provided for transferring the elongated body to the second state by bending and / or shortening the body from a larger radius of curvature to a smaller radius of curvature.

The transfer means may comprise means for bending and / or shortening the elongate body by a preferably asymmetric contraction thereof.

The elongated body may further comprise a memory material which provides for the transfer to the second state.

In a preferred embodiment, the elongated body may comprise a stent. In an alternative embodiment, the device according to the invention may comprise several stent sections, and the bending and / or shortening means may comprise wires for shortening the distance between the stent sections.

One way of reducing the circumference of the mitral valve ring comprises the steps of inserting an elongated body into the large cardiac vein near the posterior sail flap of the mitral valve device, and then to effect a bending and / or shortening of the elongated body, when placed in the large cardiac vein. to reduce its radius of curvature and thereby reduce the circumference of the mitral valve.

The method thus utilizes that the large heart vein is located near the mitral ring. This enables repair through the use of current catheter controlled techniques.

The coronary veins drain blood from the heart muscle to the right atrium. The smaller veins drain blood directly into the atrial cavity, and the larger veins follow the main arteries and run into the large heart vein, which essentially surrounds the mitral orifice and the mitral ring. The large heart vein runs into the posterior atrioventricular recess, which lies in the adipose tissue between the left atrial wall and the ventricular cardiac muscle, before opening into the right atrium between the atrial septum and the posterior Eustachi vein.

In an adult, the path of the large heart vein may be within 5-15 mm to the medial attachment of the mitral valve to the rear sling flap of the device. Preliminary measurements made at normal weight autopsies show similar results at a distance of 5.3 ± 0.6 mm at the medial attachment and approximately 10 mm at the lateral side of the posterior flap. The circumference of the large heart vein was 18.3 ± 2.9 mm at the orifice (giving a diameter of the posterior sail flap of 5.8 ± 0.9 mm) and 9.7 ± 0.6 mm along the lateral side of the posterior flap ( corresponding to a diameter of 3.1 + 0.2 mm).

514 718

The invention is more easily understood by the following description of preferred embodiments with reference to the accompanying drawings, in which:

Fig. 1 is a cross-sectional view of a heart portion.

Figures 2 and 3 are schematic views of a first embodiment of a device according to the present invention.

Figures 4-6 are schematic views showing an instrument that can be used in placing the device shown in Figures 2 and 3 in the large cardiac veins.

Fig. 7 is a partial enlargement of the first embodiment of Fig. 2.

Figures 8 and 9 are schematic views showing the location of the device of Figures 2 and 3 in the large heart veins.

Figures 10 and 11 are schematic views showing the location of a second embodiment of the device of the present invention in the large cardiac vein.

Figures 12 and 13 are schematic views showing the location of a third embodiment of the device of the present invention in the large cardiac vein.

Fig. 1 is a cross-sectional view through the cardiac region of the posterior atrioventricular depression 1, which is filled with adipose tissue. The figure shows the posterior flap 2 of the mitral valve apparatus and the adjacent portions 3, 4 of the atrial cardiac muscle as well as the ventricular cardiac muscle. The large cardiac vein 5 is shown near the mitral ring 6 and behind the attachment 7 of the rear sail flap 2. Since the large heart vein 5 essentially surrounds the mitral ring 6, a decrease in the radius of curvature of the curved large heart vein 5 also results in a decrease in the diameter and circumference of the mitral ring 6.

The device of Figure 2 comprises an elongated body 8 made of memory metal, for example Nitinol, or other similar material having a memory of an original shape shown in Figure 3 and which may be temporarily forced to take another shape which is shown in Fig. 2. This elongated body 8 comprises one, two or more

514 718 helical wire memory metal threads 9 or any other shape so that they fit together and allow the movements described below. A plurality of hooks 10 are attached to the elongated body 8 so that they project radially from it. These hooks 10 are covered by a covering housing 11 in Fig. 2.

The elongated body 8 is forced to take an extended or expanded state by means of a stabilizing instrument 12, as shown in Figure 4. This instrument 12 has two arms 13 at a distal end 14 of a rod 15 and a locking member 16 at a proximal end. of the rod 15. The distance between the ends of the rod 15 corresponds to the desired length of the elongated body 8 as it is inserted into the large cardiac vein 5.

The arms 13 are free to move between the position shown in Figure 4 and a position in line with the rod 15, as shown in Figure 6. The locking member 16 has two locking buttons 17 which are radially extruded from the rod 15 by two leaf springs.

18th Thus, the elongated body 8 can be pulled over the rod 15 of the stabilizing instrument 12, then the body is extended between the arms 13 and the buttons 17, and finally locked in its extended state on the stabilizing instrument 12 between the arms 13 and the buttons 17, as shown in Fig. 5. .

The rod 15 may be a metal wire which is relatively rigid between the distal end 14 and the locking member 16 but is so flexible that it will follow the shape of the large cardiac vein 5. The metal wire of the stabilizing instrument 11 is more flexible proximal to the locking member 16 for easily following the bends of the veins.

The elongated body 8 described above is placed in the large cardiac vein 5 as follows:

An insertion tube (not shown) of synthetic material can be used to provide access to the vein system. Once the vein system has been accessed, a long guide wire (not shown) of metal is inserted through the insertion tube and via the vein system into the large cardiac vein 5. This guide wire is

514 718 provided with X-ray distance markers so that the position of the guide wire in the large heart vein 5 can be monitored.

The elongated body 8 is locked onto the stabilizing instrument 12, as shown in Figure 5, and inserted into the long covering housing 11 of synthetic material. This assembly is then pushed through the insertion tube and the venous system up to the large heart vein 5, carried by the guide wire. After precisely positioning the elongated body 8 in the large cardiac vein 5, as shown in Fig. 8, in which the mitral valve 19 is shown including a central opening 20, the covering housing 11 is retracted and reveals the elongated body 8 within the large cardiac vein 5. This operation enables the hooks 10 of the elongated body 8 to dig into the walls of the large heart vein 5 and into the heart. The elongated body 8 is still locked on the stabilizing instrument 12 so that the hooks 10 engage the walls of the large cardiac vein 5 in the extended or expanded state of the elongated body 8.

A catheter 21, shown in Fig. 6, is pushed forwardly over the guide wire and rod 15 to release the elongated body 8 from the locking member 16, by pressing the leaf springs 18 against the rod 15. This movement releases the buttons 17 and arms 13 from engagement with the elongate member. the body 8, which is contracted as shown in Figure 9, which results in the body bending toward the mitral flap ring 6 and moving its rear portion forward (shown by arrows in Figure 9). This displacement reduces the circumference of the mitral valve ring 6 and thereby closes the central opening 20.

Fig. 7 shows part of an arrangement with the threads 9 and the hooks 10 along a peripheral part of the elongate body 8, with which arrangement the elongated body 8 will be contracted asymmetrically, resulting in a bending of the body when interconnected parts 22, comprising at least some of the hooks 10, shortened to its original shape.

514 718

Figs. 10 and 11 show an alternative embodiment of an elongated body 8 ', which is a solid wire, in the form of an open, U-shaped ring, which will engage the wall of the large cardiac veins 5, closest to the mitral valve ring 6, when the body is inserted into the large cardiac vein 5. The elongated body 8 'consists of a memory metal material which, when returning to its original shape, will bend, as shown in Fig. 11. The return of the open ring 8 'to its original form can be initiated in several ways, which will be apparent to one skilled in the art.

The third embodiment of the elongated body 8, shown in Figs. 12 and 13, comprises three stent sections 23-25 ​​located at one end of the elongate body 8, at the center thereof, and at the other end of the elongated body 8, respectively. These stent sections 23-25 ​​can be placed in the large heart vein 5 as shown by conventional means so that their positions are locked. The sections are connected by wires 26, 27, which can be operated from the exterior of the vein system so that the distances between the adjacent stent sections 23, 24 and 24, 25 are reduced. More specifically, the distances are reduced asymmetrically, ie more on the side of the large cardiac vein 5 which is closest to the posterior part of the mitral valve ring 6. Thereby, the elongated body 8 bends, as shown in Fig. 13, and presses the large heart vein 5 against the mitral valve ring 6 and closes the opening 20.

In summary, the present invention provides a device located in the large cardiac vein which is designed to reduce the mitral ring dilation. This device is at a distance from the rear sail flap attachment, which does not greatly exceed the distance at which now used annular plastic rings are placed by open surgical methods, and the large heart vein is along its entire path sufficiently large to accommodate such a device. . The device can be put in place by catheter or other appropriate technique and offers a safer al514 71.8 alternative to current open surgical methods. The device can be designed or heparin-coated gas to avoid thrombosis of the large heart vein, thereby reducing the need for treatment with aspirin, ticlopedin or anti-coagulants.

It will be appreciated that modifications to the above-described device can be made by persons skilled in the art without circumventing the spirit and scope of the invention.

514 718