RU174786U1 - FRAME OF BIODESINE INTEGRATED INTRAVENOUS FILTER - Google Patents

Abstract

The utility model relates to medicine, namely to biodegradable intravenous filters, and can be used in x-ray surgery to capture blood clots in blood vessels. The framework of the biodegradable intravenous filter has an upper part and a lower one. The lower part contains at least four strata bent at an acute angle, and the upper part contains spacer rods comparable in number to them, the ends of one of the sides of which are connected to two ends from two different strata at one point. On their other side, the strut rods, namely the sections of their end parts, are interconnected in various ways to contain each other, while providing a small cross-sectional area of the upper part of the frame, which preserves the blood flow direction in the vascular bed. 3 of FIG.

Description

FIELD OF TECHNOLOGY

The utility model relates to medicine, namely to biodegradable intravenous filters, and can be used in x-ray surgery to capture blood clots in blood vessels.

BACKGROUND

Known intravenous (WO2006020425), in which the frame has an upper part and a lower part, where the lower part contains a set of strata bent at an angle, and the upper part contains spacer rods comparable in number to them, the ends of one of the sides of which are connected to two ends from two different striations at one point, and the ends of the other side of the spacer rods are connected at one point (clip) and are additionally connected to each other by a fixing element of a biodegradable material of a zigzag shape. The known invention is selected as a prototype.

A disadvantage of the known filter is that the zigzag (ring-shaped) fixing element near the filter holder reduces the cross-sectional area of the vessel, not only preventing the spread of the blood clot, but also to a greater extent changes the blood flow, thereby causing thrombosis. Also, when dissolved, this additional element does not attach anywhere and can migrate subsequently, creating a risk of death in patients.

The proposed utility model avoids the above disadvantages of the prototype.

DISCLOSURE OF A USEFUL MODEL

The task to which the proposed utility model is directed is to create a new framework of a biodegradable intravenous filter of a simpler design that ensures proper fixation in the vessel while maintaining reliable filtration of thromboembolas and allows the filter to be installed from any access for people of any age, without the need for subsequent removal.

The technical result achieved when using the utility model is to increase the reliability of fixing the filter frame in a vessel while simplifying the design and increasing the safety of its use.

The task and the required technical result are achieved by the fact that the new frame of the biodegradable intravenous filter having an upper part and a lower part, where the lower part contains at least four strata curved at an acute angle, and the upper part contains rods comparable in number to them spacers, the ends of one of the sides of which are connected to two ends from two different strata at one point, and with their other side, the spacer bars are connected to a fixing element of biodegradable material, characterized This is due to the fact that the fixing element is a portion of the end parts of the spacer rods connected in various ways to contain each other, while ensuring a small cross-sectional area of the upper part of the frame, which preserves the blood flow direction in the vascular bed.

In one embodiment of the utility model, the end parts of the strut bars are in intersection with each other.

An essential feature of the proposed framework of a biodegradable intravenous filter is its new design, in which only “working” elements are present, i.e. no extra elements. The use of the end parts of the spacer rods as a fixing element, i.e. their continuation, and not a separate ring-shaped element as in the prototype, allows to increase the cross-sectional area for the blood duct, and to protect the frame itself from possible separation of elements. In this case, the end parts of the frame strut rods are connected in such a configuration (form) that provides a small cross-sectional area of the upper part of the frame, which preserves the blood flow direction in the vascular bed, which, unlike the prototype, allows you to distribute mechanical stress so that it does not fall on the middle of the spacer rods, allowing them not to break during dissolution.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 - presents a three-dimensional image of the frame (in a free state), in which the end parts of the spacer rods are in intersection with each other.

In FIG. 2 is a side view of the chassis of FIG. one.

In FIG. 3 is a top view of the chassis of FIG. one.

IMPLEMENTATION OF A USEFUL MODEL

The frame 1 has a lower part formed by at least four strips 2 curved at an acute angle, and an upper part formed by at least four spacer rods 3. The frame 1 is thus represented on one side by an outer ring formed by a set of striations 2, and on the other hand, spacer rods 3, assembled and fixed in the upper part of the frame 1 in various ways. The fixing method (form of connection) of the spacer rods 3, namely their end parts, can be any acceptable for a particular implementation of the frame. However, in all cases of the implementation of the framework, the selected form of the connection should provide a small cross-sectional area of the upper part of the framework, preserving the blood flow direction in the vascular bed.

An example of such an implementation may be the frame depicted in FIG. 1-3, in which the end parts of the spacer rods 3 are in intersection with each other, forming in the form of a top view (Fig. 3) a star-shaped figure.

The above option (Fig. 1-3):

- has the necessary separation (fixation) of the spacer rods 3 while increasing the efficiency of the capture of thromboembolas, i.e. filtration compared to the prototype frame;

- provides a small cross-sectional area of the upper part of the frame 1 and save in the vascular bed of the direction of blood flow.

- allows you to distribute the mechanical stress so that it does not fall on the middle of the spacer rods 3, allowing them not to break during dissolution.

In addition, the embodiment of the carcass 1 shown in FIG. 1-3, has increased radial stability, in the absence of stress in the region of the stratum 2. This contributes to the additional distribution of mechanical stress on the elements of the frame 1, allowing them not to break during dissolution.

Four strata 2 and, respectively, four spacers are minimum 3. The number of strata 2 and spacer bars should be comparable in number, since in the central part of the frame 1, each end of the spacer bars 3 on their respective side is connected to two ends from two different strata 2 at one point 4. If the stratum 2 and the spacer rods 3 are less than four, then the filter frame will not be able to effectively filter blood clots in the system of the inferior vena cava. Table 1 below shows the dimensions of the filter frame 1.

Table 1. Filter Dimensions

Parameter Name Value 1. Length (L) mm 30 - 50 2. Diameter (W) of the cross section, mm 20 - 40 3. The diameter of the fibers, mm 0.5 - 1.5 4. Angle (α), FIG. 1 degree 10 - 170

The length of the cross-section is due to the convenience of installing a cava filter through a catheter introducer using pushers, as well as to make the product partially in the bloodstream and partially pressed against the vein wall.

The diameter of the cross section is limited by the size of the human vein (about 1-2 cm) into which the cava filter should be implanted, and under the conditions of the implanted device, it should exceed the norm by 70%.

The fiber diameter is chosen to achieve radial stability and mechanical resistance of the object in order to achieve a pressure force on the wall of the vein of 1 N or more.

The angle of the rings is chosen in this way, but not limited to them, in order to achieve the development of the cava filter in the vein cavity.

The frame 1 of the filter is made of biodegradable material. As the material of the carcass 1, a copolymer of D, L-lactide and glycolide with a molecular weight of 75,000 to 200,000 Da with a composition in a molar ratio of 50.00-99.99: 0.01-50.00, or copolymer D, L can be used -lactide, trimethyl decarbonate and glycolide with a molecular weight of 75,000-200,000 Yes with a composition in a molar ratio of 0.01-75.00: 0.01-99.98: 0.01-24.99. This material is elastic, provides fixation of the frame 1 of the intravenous filter inside the vein and dissolves in the bloodstream.

The L-lactide polymer (LLA) is made by polycondensation of L-lactic acid, followed by thermal decomposition and cyclization.

Glycolide (GA) is made from glycolic acid under similar conditions.

Both monomers are purified five times by recrystallization from ethyl acetate. LLA, GA, and dried in vacuo at room temperature for 72 hours.

Monomers and copolymers are ring-opened synthesized by polymerization of the respective monomer streams using SnOct ₂ as a catalyst. The molar ratio remains constant and equal to 2000/1. Monomers and catalyst are loaded into a silane polymerization tube. After degassing, the tube is sealed under vacuum, after which the polymerization proceeds at a temperature of 130 ° C for 72 hours. The resulting polymers are restored by dissolving in dichloromethane, and the precipitation in methanol, and then dried in vacuum at room temperature. In this way, poly (lactide-D, L-glycolide) is synthesized.

Then this copolymer is used to produce bars of the required diameter. For this, it is extruded through a die using a single screw extruder (screw diameter = 3 mm). The screw speed is maintained at 40 rpm. The temperature of the drum is from 150 to 170 ° C.

The final dimensions of the bar are from 1.0–2.0 mm in diameter and 12.0 mm in length.

The construction of the frame 1 is carried out using a 3D printer based on poly-L-lactide and / or using a laser and / or injection molding of products. The structure is cleaned of support material manually. Next, an intravenous filter is inserted into a 7 F diameter catheter introducer (service jacket) and the device is sterilized assembled. After sterilization, the device is packaged in a sterile package.

The implantation of the frame 1 of an intravenous filter is carried out after a diagnostic study that established pulmonary embolism or float thrombosis of the lower hollow, deep veins of the lower limb, iliac or femoral veins, as well as in patients with repeated pulmonary embolism with an undetected source of relapse.

The frame 1 of the intravenous filter is implanted in the inferior vena cava with the lumen of the catheter cap down so that the spacer rods are below the mouth of the renal veins at the level of the intervertebral disc L1-L2 and the upper edge of the L2 vertebra. When implanting the device, percutaneous catheterization of the subclavian, right internal jugular or femoral veins is used.

A wired Teflon cannula is installed below the mouth of the renal veins. In the case of emergency access, the IF is inserted into the conduction cannula with the legs forward, in the case of transclavicular or emergency access, the lumen of the metal cap is facing down. When pushed through an implant catheter, the intravenous filter is in a compressed state. When the inferior vena cava reaches the loop-pusher, the filter is passed through the lumen of the cap into the vascular bed, where it opens, and the spacer rods of the upper and lower tiers abut against the walls of the vein. Then, by moving in the opposite direction, the filter is fixed with hooks to the vein wall. Then the extractor is removed, and a control contrast of the inferior vena cava is performed.

The wire cannula is removed, the bleeding is stopped by finger pressing of the puncture site.

The proposed frame 1 can be manufactured on existing equipment using materials approved for use in medical practice. For example, using a Picasso 3D Designer Pro 250 3D printer and / or a Satsumi femtosecond laser.

Although the present utility model has been described in detail with examples of options that appear to be preferred, it must be remembered that these embodiments of the utility model are provided only to illustrate the utility model. This description should not be construed as limiting the scope of the utility model, since the described construction of the frame and the stages of its preparation by specialists in the field of medicine, chemistry, physics, etc. can be amended to adapt them to specific frame designs or situations, and not beyond the scope of the attached utility model formula. The person skilled in the art understands that within the scope of the utility model, which is determined by the claims of the utility model, various options and modifications are possible, including equivalent solutions.

Claims (1)

The frame of a biodegradable intravenous filter having an upper part and a lower part, where the lower part contains at least four elements bent at an acute angle (as shown in Fig. 1), and the upper part contains spacer rods that are comparable in number to them, the ends one of the sides of which are connected to two ends from two different elements at one point, and the end sections of its other side are strut bars in intersection with each other to restrain each other, while ensuring sufficient passing the blood-retarded, but containment of thrombus cross sectional area of the upper part of the frame is stored in the bloodstream direction krovopotoka.

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