RU156774U1 - BIOLOGICAL PROSTHESIS FOR REPROTHESIS OF HEART VALVES - Google Patents

Abstract

1. Biological prosthesis for prosthetics of heart valves, including a flexible cylindrical frame, the wall of which has a honeycomb structure, and a biological leaflet mounted on the frame, characterized in that the output section of the frame is made with the possibility of formation during the implantation of the expansion to form an engagement with the supporting frame element previously implanted heart valve prosthesis, while the formed expansion extends beyond the cylindrical frame by 1-10 mm and gives the frame a cup shape. 2. A biological prosthesis according to claim 1, characterized in that the honeycomb frame contains support legs of the leaflet commissures. The biological prosthesis according to claim 1, characterized in that the cellular structure of the frame is formed by beams with a width of 0.1-0.9 mm and a length of 0.1-10 mm. The biological prosthesis according to claim 1, characterized in that the cell beams contain holes with a diameter of 0.05-1 mm.

Description

BIOLOGICAL PROSTHESIS FOR REPROTHESIS OF HEART VALVES

The utility model relates to medicine, namely to cardiovascular surgery, and can be used to replace previously implanted biological prostheses of heart valves in the event of their structural dysfunctions.

Despite the significant number of developments in the world in the field of creating and improving biological heart valves, a significant number of patients require repeated operations on the valve apparatus due to the dysfunction of previously implanted prostheses.

Repeated heart surgeries are known to be associated with an increased risk of adverse outcome, especially in groups of elderly patients with concomitant pathologies such as renal failure, lung disease, cognitive impairment, high functional class of heart failure, etc. In addition, the removal of earlier an implanted device is a traumatic procedure and can lead to insolvency of the fibrous ring and damage to the conduction system of the heart. Often repeated interventions are carried out on an emergency basis in conditions of limited ability to stabilize the vital functions of the body, indicators of hemostasis, blood coagulation. In such conditions, the search for new technical solutions aimed at minimizing injuries and the time of surgical intervention becomes relevant.

Known heart valve prosthesis for replacing previously implanted (US Pat. No. 8,591,570 B2: IPC A61F 2/24. Prosthetic heart valve for replacing previously implanted heart valve [Text] / Assignee: Medtronic Inc. (US); filed 03/07/08, date of patent November 26, 2013), the design of which includes a metal frame with shape memory with a sewn biological casement device, while fixing the device in the old frame is carried out by means of external anchors located at the end sections of the prosthesis.

A disadvantage of the known device is the fixation system of the new frame, which is not universal and requires precise positioning in the old frame depending on the size of the primary frame, or a modification of the old frame to secure the new prosthesis.

Known biological prosthesis of the heart valve intended for reimplantation (Pat. 2438621 Russian Federation: IPC A61F 2/24 Reimplantable biological prosthesis of the heart valve [Text] / SV. Evdokimov VT Kostava, AS Evdokimov, etc .; patent holder Evdokimov CB (RU), Kostava V.T. (RU). - No.2010132802 / 14; decl. 04.08.10; publ. 10.01.12, Bull. 1. - 8 p.). The prosthesis consists of an annular body with three legs and a cuff, inside of which there is a rigid frame. Additionally, the cuff is equipped with support and locking elements designed to fix the annular body, on the outer surface of which a protrusion is made. The locking element is made in the form of a split ring, with the possibility of increasing the inner diameter by spreading two cams on the outer surface of the cuff. The inner and end surfaces of the hull and racks are shrouded in a xenopericardium plate.

A disadvantage of the known device is that with the development of fibrosis in the implantation zone of the cuff of the primary prosthesis, the removal of the body may be difficult due to the growth of the sliding cams in the surrounding tissue. The disadvantages of this technical solution include the fact that it is intended for primary implantation and excludes the possibility of reimplantation of other models of prostheses.

The prior art transcatheter aortic valve replacement system CoreValve (Medtronic, Inc.) is known for replacing failed valves both primary and secondary using a valve-in-valve technique (Piazza Ν, Often A, Schultz C, et al Adherence to patient selection criteria using the third generation 18F CoreValve ReValving System. Heart 2010; 96: 19-26). The known device contains a self-expanding nitinol skeleton with a fixed leaflet made of biological material. The implantable device is packaged in a delivery system that provides gradual release of the prosthesis. The valve is implanted in the excretory tract of the left ventricle with a transition to the ascending part of the aorta, while the cellular structure of the skeleton provides the possibility of maintaining coronary perfusion.

The disadvantages of the known device is the high cost of the device, as well as the fact that implantation is possible only in the aortic position. At the same time, the implantation of this prosthesis is carried out using a transfemoral delivery system, however, pronounced calcification and tortuosity of the iliac arteries may not allow the intervention to be performed through the femoral access.

Closest to the claimed technical solution is the Edwards Sapien biological prosthesis (Edwards Lifesciences), which is used to replace a failed prosthesis using a valve-in-valve technique (Piazza N. Et al. Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve : from concept to clinical application and evaluation (part 2) // JACC: Cardiovascular Interventions 2011a; 7: 733-742.). The device is made in the form of a balloon-expandable frame prosthesis made of cobalt-chromium alloy sheathed with biological material and containing three bovine pericardial valves. Delivery and installation of this prosthesis is carried out by means of transcatheter 4

devices, and upon reaching the positioning position, the balloon is expanded by straightening and fixing the frame in the region of the old prosthesis.

The disadvantage of this technical solution is that after opening the prosthesis takes a cylindrical shape and is held in the zone of the fibrous ring only due to the radial bursting forces of the frame, as a result of which incomplete fixation of the reimplantable prosthesis is possible, leading to its disposition and incomplete tightness in the area of contact with the old wall frame. Also, this technical solution eliminates the possibility of removing a degraded biological casement device, which limits the choice of the optimal size of the prosthesis.

The aim of the development of the proposed device is the creation of a heart valve prosthesis designed for open reprosthesis of an insolvent frame biological prosthesis of a heart valve using a seamless valve-to-valve implantation.

The technical result of the utility model is to reduce the incidence of cardiovascular complications during repeated surgical interventions to replace heart valves.

The technical result is achieved due to the fact that the proposed device consists of a flexible frame with a cellular wall structure and mounted on a biological leaflet, while the output section of the frame is made with the possibility of formation during the implantation of the expansion to form an engagement for the supporting frame element of the previously implanted valve prosthesis hearts.

The frame is made in the form of a hollow cylindrical structure, the walls of which have a cellular structure of closed or open types, as well as their combination with a beam width of 0.1-0.9 mm and a length of 0.1-10 mm. The beam section can be parallelogram, or round, or ellipsoid, or triangular, or polygonal. To increase the rigidity of the frame, the design may contain support racks commissures 5

casement apparatus. These racks may contain holes with a diameter of 0.05-1 mm for hemming the sash and fixing the lining.

The supporting frame may be made of metal, for example, stainless steel, an alloy of cobalt-chromium, tantalum, gold, as well as polymers, for example silicone, polyurethane or polypropylene, a combination of the above materials. The manufacture of the support frame is carried out by laser cutting of a pipe or sheet of material with a thickness of 0.1-0.9 mm, followed by giving the final shape and diameter. To increase biocompatibility and remove sharp edges and burrs, the support frame is subjected to ultrasound and electro-polishing. The sizes of the supporting frame should cover the entire range of final diameters of known bioprostheses of heart valves 18-34 mm.

The essence of the utility model is illustrated by drawings, which depict:

in FIG. 1 - reimplantable prosthesis of the valve assembly, where 1 is the supporting cellular frame, 2 is the biological sash, 3 is the skin of the frame, 4 is the rack commissures of the sash, 5 is the hole for suture material, 7 is suture material;

in FIG. 2a-2c show variants of the cellular structure of the walls of the supporting frame; 2a - a six-beam supporting frame of the proposed prosthesis, 2b - a fully cellular supporting frame, 2c - an embodiment of the supporting frame of the prosthesis with rigid struts;

in FIG. 3a-3c is a view of the implanted frame in the supporting element of the old prosthesis; where in FIG. 3a - the claimed prosthesis installed in the supporting frame 6 of the "old" heart valve prosthesis, isometric view, in FIG. 3b is the same, but with a fully cellular version of the support frame, in FIG. 3c - the same, but completely rigid struts 4 frames;

in FIG. 4 shows a swollen balloon 8 with a prosthetic heart valve, schematically.

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An extension in the form of a truncated cone is made in the output zone of the supporting frame 1, which gives the frame a "bowl" shape and ensure reliable fixation of the prosthesis at the implantation site. These bending shapes are formed in such a way as to go 1-10 mm out of the plane of the cylinder formed by the carcass 1, thereby securing the structure for the supporting element 6 of the “old” insolvent prosthesis. The main function of the supporting frame 1 is to maintain the shape of the cuspid 2 and casing 3, as well as to create a force sufficient to counter the biasing force of the bloodstream and to secure the prosthesis at the implantation site.

The flap apparatus 2 of the prosthesis consists of three identical flaps made of biological or biocompatible material, mounted according to known technologies on the supporting frame 1 due to the holes 5 of the supporting posts 4 and / or holes 5 of the cells using medical suture material 7 intended for prolonged use in the patient’s body . All flaps are connected to the casing 3 of the prosthesis also due to suture material 7. The function of the flap apparatus 2 is to prevent the return of blood through the prosthesis, by creating a reliable closure of the three flaps.

Sheathing 3 of the bioprosthesis is a biological or biocompatible material mounted in the inflow and / or outlet zone of the frame 1 using suture material 7 and holes 5 made on the posts 4 of the beams of the cellular frame 1. The function of the sheathing 3 is to prevent blood leaks bypassing the leaf apparatus, as well as blood contact with the material of the supporting frame 1.

The flap apparatus 2 and the casing 3 can be made of biological material, for example, stabilized pericardium of cattle or small cattle, pigs, kangaroos. As the stabilizer, epoxy compounds and / or glutaraldehyde can be used. As the material can be used material of non-biological origin - polymers, for example PTFE, polyester, polycaprolactone.

The manufacture of the flap apparatus is carried out using laser cutting, or cutting with a surgical tool, or by carving elements, or by a combination of these techniques from a flat sheet of material using known technologies. The obtained elements of the leaflet 2 and casing 3 can be further modified to increase resistance to thrombosis and calcination according to known technologies.

The claimed prosthesis is intended to replace the "old" insolvent frame biological prosthesis of the heart valve without removing the latter. The design of the claimed prosthesis allows you to abandon the use of sutures when installing it and removing the "old" prosthesis and, thus, reduces the number and frequency of cardiovascular complications during repeated surgical interventions.

The implantation of the proposed prosthesis is carried out as follows: after providing standard open access to the previously installed insolvent prosthesis of the heart valve, the surgeon estimates the volume and degree of intervention, as well as selects the required size of the claimed device. The surgeon can perform a partial decalcification of the implantation site, as well as excision of the flap apparatus of the "old" prosthesis. The assistant crimps - fixes - the “new” prosthesis on balloon 8 using a special installation. Due to this procedure, the final diameter of the "new" prosthesis is reduced, which allows you to enter it into the implantation area in the future. After positioning the “new” prosthesis, the surgeon inflates the balloon 10, which, with an increase in internal pressure to 1-10 atm., Increases its diameter to the required (18-34 mm) and gives the final shape to the claimed product. In this case, the output section of the cellular frame 1 bends under the action of bursting forces by 1-10 mm, forming the final shape of the prosthesis in the form of a "bowl". Having achieved the necessary fixation of the “new” prosthesis, the surgeon blows off the balloon 8, and then completes the intervention according to the standard scenario.

With a contraction of the ventricle or atrium, depending on the position of the prosthesis, at the moment of excess of pressure before the prosthesis, the valves of the 2 prosthesis open and the blood is released through the latter. Further, as the pressure of the ventricle or atrium decreases, under the influence of the back pressure, the valves of the prosthesis 2 are locked and the blood flow is prevented.

Claims (4)

1. Biological prosthesis for prosthetics of heart valves, including a flexible cylindrical frame, the wall of which has a honeycomb structure, and a biological leaflet mounted on the frame, characterized in that the output section of the frame is configured to form an expansion during implantation to form an engagement with the supporting frame element previously implanted prosthesis of the heart valve, while the formed expansion extends beyond the cylindrical frame by 1-10 mm and gives the frame a cup shape. 2. The biological prosthesis according to claim 1, characterized in that the honeycomb frame comprises support legs of the leaflet commissures. 3. The biological prosthesis according to claim 1, characterized in that the cellular structure of the frame is formed by beams with a width of 0.1-0.9 mm and a length of 0.1-10 mm. 4. The biological prosthesis according to claim 1, characterized in that the beams of the cells contain holes with a diameter of 0.05-1 mm

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