THE OCCLUDER DEVICE FOR CARDIOVASCULAR SYSTEM

TECHNICAL FIELD

The invention is related to the "occluder device" for cardiovascular system and its production process. The occluder device is self-expanding, comprising of braided wire mesh made of a memory material similar to nitinol (nickel-titanium), alloy or metal, thread mesh, natural or artificial matrix. The exterior of the braided wire mesh has been coated with biocompatible material such as gold through various technological methods in order to prevent the secretion and releasing of nickel into the tissues in time, which may be harmful to the human body. The final shape of the device with a hollow design is formed with heat treatment process, and it gains self- expandability. The device consists of an expandable body part which occludes with a partly hollow holder. The body part consists of the proximal retention zone, neck and distal retention zone parts and it is placed in the patients with its specific carrier apparatus.

PRIOR ART

As it is known, defects in the heart due to congenital heart diseases in children or due to abnormal blood vessels outside the heart which are normally supposed to be covered but have not been covered may be present. This type of heart and vascular diseases can be seen in adults but not as common as in children.

For the closure of these defects in cardiovascular system, lumen occlusion devices in different shapes and structures have been used since the past. These devices can be placed by transcatheter methods which require no surgical intervention. Especially in the last ten years, we can see the rapid development in this area. The most common types have been manufactured from nitinol like metal alloy wires known as memory metal. Such devices include a releasable connection apparatus after it has been inserted into appropriate places via the catheter. Also it has a carrier system such that the device can be pulled back into the sheath if the location is not suitable and then can be taken out again.

One of the first examples is the "Amplatzer" branded occluder device of Aga Medical Corporation, and it had two separate welding points; one in the front and one at the back of the lumen occluder device, and all the wires made of nitinol alloy, which establishes the system, were connected together by these two points welding. Then the "Occlutech" branded occluder device that belongs to Occlutech Holding AG was available at the market. Although this device was made of wires with the same alloy and similar design, all the wires were attached together with only one point welding. Thus a lighter device was obtained with only one point welding, and when compared with the other devices, it is stated that less metal load has been imposed to the human body. In following-years, generally the shape of the device or connection apparatus were modified but nitinol, a memory metal, was used in all of them. Screw was used as a connector apparatus in the first twos, and different mechanical apparatus were proposed for the devices developed later.

Nowadays, there is valid rule applies to all implants made of nitinol alloy as it applies to all other metal alloys, and this rule is; unnecessary metal load should not be installed into the human body, if there is no other resort but the implant placement, then the lightest should be preferred. Because metal ions are gradually released from the implant over the years and this can lead to some complications.

BRIEF DESCRIPTION OF THE INVENTIO

The hole in interatrial septum between the two atria of the heart is called "atrial septal defect" and if it is too small, it is called "patent foramen ovale". The hole in the interventricular septum between the two ventricles of the heart is known as "ventricular septal defect". In addition, "patent ductus arteriosus" is another defect to be occluded. Furthermore in order to prevent thrombus build-up in the left atrial appendage in the elderly patients with heart diseases, "occluder device for left atrial appendage" is placed. Thus, surgical intervention of a cardiac surgeon is no longer required for the closure of such defects. Lumen occlusion devices in different shapes and structures are placed by transcatheter methods and occlusion is achieved through the sheath positioned in the groin artery and conveying systems. Occlusion devices known as memory metal wires are made from metal alloys like nitinol. In general, the shape or connection apparatus have been modified in all of the devices but nitinol, which is a memory metal, is still used. Screws are used as the connection apparatus in some devices, but various mechanical apparatus have been proposed in the devices developed later. Nobody knows what problems the metal ions released from the inserted implant will lead to in the years ahead, and at this respect, our invention is one of the lightest metal load occluder devices that have ever been developed, and that is, although the proximal retention zone forms a disc-shaped body, the center of distal retention area is open. It has been designed like basket and looks as if it is an outspread hem of a whirling dervish's skirt, and thus, it has formed a lighter structure than its counterparts. Employing natural or artificial or dermal matrix with or without silk fibers in order to provide complete occlusion also provide additional advantages to the system.

LIST OF FIGURES

Figure 1. Four-Hollow Section of the Heart, and the View of the Occluder Device from its Location

Figure 2. The View of the Occluder Device Used in the Atrial Septal Defect Closure Figure 3. The View of the Occluder Device Used in Patent Foramen Ovale Closure Figure 4. The View of the Occluder Device Used in Ventricular Septal Defect Closure Device

Figure 5. The Lateral Sectional View of the Device Used in Perimembraneous Ventricular Septal Defect Closure

Figure 6. The Anterior Sectional View of the Device Used in Perimembraneous Ventricular Septal Defect Closure

Figure 7. The Superior Radius Sectional View of the Device Used in Perimembraneous Ventricular Septal Defect Closure

Figure 8. The View of the Device Used in the Patent Ductus Arteriosus Closure Figure 9. The View of the Occluder Device Used in Vessels

Figure 10.The View of the Conical Shaped Occluder Device Used in Patent Ductus

Arteriosus Closure

Figure 11. Manufacturing Process

Figure 12. Whirling Dervish

Figure 13. Natural or Artificial Dermal Matrix and Fixing Seams

Figure 14. The View of the Occluder Device Used in Left Atrial Appendage

Closure, (A: for narrow and long appendage B: for wide-mouthed appendage) Provision of the track numbers specified in the figures is given below.

1. Occluder Device

1.1. Memory Wire Ball

1.2. Proximal Retention Area

1.3. Neck Area

1.4. Distal Retention Area

1 .5. Connection Apparatus

1.6. Silk Fiber

1.7. Natural or Artificial Dermal Matrix

1.8. Dermal Matrix Fixing Seams

1.9. Marker

2. Transport Apparatus

2.1. Sheath

2.2. Spiral Wire Carrier

2.3. Holder Apparatus for the Spiral Wire Carrier

DETAILED DESCRIPTION OF THE INVENTION

The present invention occluder device (1 ) has been made of wires prepared from the nitinol alloy, which is a nickel-titanium alloy known as memory material, or made of a memory polymeric material. The occluder device (1 ) mainly consists of memory wire ball (1.1), the proximal retention zone (1.2), neck zone (1.3), distal retention zone (1.4), the connection apparatus (1.5), the silk fiber (1.6) inside the memory wire ball (1.1 ), natural or artificial acellular dermal matrix (1.7), and dermal matrix fixing seams (1.8).

The transport device (2) is a system which carries the occluder device (1) through the groin vessels up to the place where it will be applied with transcatheter method. The transport apparatus (2) is mainly made up of the sheath (2.1 ), the spiral wire carrier (2.2), and the holder apparatus for the spiral wire carrier (2.3).

While the occluder devices (1) perform their duties, they are required not to harm the human body. The concern is that the metal ions released from inserted implants may lead to some troubles in later years. Therefore, the design of the lighter occluder devices (1) has been dealt with. Our invention is one of the lightest occluder devices that have ever been developed. This feature is important since especially the nickel ions in nitinol alloy can be detrimental to the human body, so the lightest ones should be preferred if there is no other choice but a device should be placed.

The occluder device (1 ) can be obtained by manually winding nitinol wire on a simple mold in a particular pattern, and it attains flexibility and memory property after heat treatment. Its special design like an uncovered basket makes it possible to wind easily.

Our invention is one of the lightest occluder devices that have ever been developed with its light metal load; that is, although the proximal retention zone (1 .2) has a disc-shaped volume, the center of the distal retention zone (1 .4) is open. It has been designed like basket and looks as if it is an outspread hem of a whirling dervish, and that is why it is lighter than its counterparts. Wing

Additional benefits are provided to the system by way of employing natural or artificial dermal matrix (1 .7) instead of silk fibers for assuring complete blockage.

Another method developed to prevent the release of especially nickel ions into the blood and tissues in time is to coat the device with metal like gold or polymeric material by using various methods. This thin layer prevents corrosion of the device and the release of metal and also provides a faster recovery.

One of the important problems encountered especially during the perimembranous ventricular septal defect occlusion is that the wings of the proximal retention zone (1 .2) and of the distal retention zone (1 .3) are in close proximity to the heart valves and the heart conduction pathway and thus the wings damages the heart valves and heart conduction pathway. As a solution to this problem, the edge of the device (1 ) has been designed semi-circular or oval. In addition, when viewed from the side it represents an asymmetric and radial structure. Thus, during the perimembranous ventricular septal defect occlusion, it enables the occluder device (1 ) to locate into the defect completely.

Our occluder device (1 ) contains at least one marker (1 .9) to help cardiologists to see whether it has been located in the right place and in the right position. Thus, especially during occlusion of perimembranous ventricular septal defect, the position of asymmetric and radius retention zone of the occluder device (1 ) can be monitored more appropriately through X-ray fluoroscopy.

Left atrial appendage is in the form of a glove finger and has a curved structure. Although the device that will occlude this zone consists of proximal, neck and distal parts, the front and back sides of the wire mesh winding has been designed as curved outwardly in the form of tabs so that it can cling to the folds of the appendix and cannot come off. Silk fibers, natural or artificial acellular dermal matrix have been placed into this device also. The structural properties of the occluder device used for the closure of the left atrial appendage mouth or for filling interior of the appendix, should depend on whether the anatomical features of the appendix mouth is narrow, long or wide. If a narrow-mouthed long appendix view has been obtained through different imaging methods, narrow-long and flexible devices (A) should be used in the patient. If the appendage is wide-mouthed, then wide and a little harder devices (B) designed for wide-mouthed appendix should be preferred. Whether the devices are rigid or slightly flexible is related to the thickness of the wire they are made of, and if it is made from thinner wire, the device becomes more flexible, and the device becomes more rigid if it is made of thicker wire. The surfaces of the proximal retention area (1 .2) facing the left atrium has been coated with biocompatible and anti-fibrin material so that new thrombus formation, due to the nickel-titanium alloy content of the sides of the occluder device used for the occlusion of the mouth of the left atrial appendage, is prevented.

Acellular dermal allograft is a genuine human skin donation obtained from human. It is a natural material derived from undamaged dermal tissue matrix. This material has great advantages for both surgeons and patients. The vital components of this material have been removed and the material has been made acellular in order to prevent immune/infection response and tissue rejection. Physically, it is extremely soft, however, it is resistant to stresses and flexion, and is easy to shape. With the advances in recent years, it is now possible to make physical "artificial dermal matrix" or "artificial scaffold" in the desired form with the method of "three- dimensional tissue scaffold system". Three-dimensional dermal tissue scaffold or matrix is manufactured with specific bio-compatible polymeric materials using mechatronic systems. The recent manufacture of these new natural or artificial matrixes has brought major benefits to our invention. Since they do not include any cells or cell fragments, they do not cause allergic or immunologic reactions, and they are not rejected by the body, and they play an important role in the realization of a complete occlusion, and they also accelerate endothelialization after the process. Moreover, the natural matrix is organized in time among the healthy tissues, and the artificial matrix developed from biocompatible polymer dissolves over time and disappears in the body.

As to the advantages of these developments associated with our invention; as known it has been intended to achieve a complete occlusion quickly through the clinging of the blood platelets on the silk fiber inserted into the occluder device. Thus, blood fibrin fibers together with platelets will prevent possible blood leakage through the biocompatible memory wire like nitinol. When the natural or artificial acellular dermal matrix is placed instead of silk fiber and these are fixed to the nitinol wire, this structuring will provide an additional biomechanical force to the device. As they are soft and can be shaped easily, they can be loaded into the transport system of the device together with the device itself without causing any additional resistance. When the device is released in patient, this natural or artificial dermal matrix will be opened when the occluder device is opened, and total occlusion will be achieved with the blood-proofing property of the matrix. It is also expected that endocardial surface of the heart or endothelial layer of the blood vessels will coat the device much faster.

One of the other features of the occluder devices is that they are required to be designed in various sizes from small to large so that their proximal and distal retention zones and neck regions can be applied in all sizes of defects and in patients of all ages. The manufacture of the device should be planned in all sizes from the narrowest defect (2 mm) up to the largest defect.