WO2001008598A1

WO2001008598A1 - Temporary prosthesis

Info

Publication number: WO2001008598A1
Application number: PCT/IL1999/000426
Authority: WO
Inventors: Valerian Voinov; Romul Boldyrev
Original assignee: Brainwave Cardio-Vascular Technologies Ltd.
Priority date: 1999-08-03
Filing date: 1999-08-03
Publication date: 2001-02-08
Also published as: AU5190299A

Abstract

Temporary Prosthesis for insertion into the area of the weakened sections of the tracheal ring cartilages is formed exclusively by the ring structure constructive elements, and provided with a device for the prosthesis removal from the trachea, according to clinical diagnostics recommendations.

Description

TEMPORARY PROSTHESIS Field and Background of the Invention This invention relates generally to the medical technology, particularly, to the prosthesis which is intended for strengthening the tracheal cartilages ring sections and for securing the natural viability of the respiratory tract parts. The prosthetics of the coronary vessels with the help of tubular metal scaffoldings, executed in the shape of different modifications stents, is already known. The examples of common designs in patents are: US 4.733.665, US 4.969.458, US 5.102.417, US 5.195.994, US 5.513.444, WO 91FR013820, etc. At the same time, there is a problem of strengthening the weakened tracheal cartilages ring sections, that could in essence be resolved with the use of metal prosthesis similar to the one mentioned above. The most suitable for this are exactly the ring structures of the tracheal cartilages which could successfully be combined with ring structure of the tracheal cartilages. The applied methods of treating the stenosed tracheal cartilage sections or smaller respiratory tract parts are painful enough and, as a rule, are ineffective. That is why, offered here is a metal prosthesis in a form of a ring structure specially oriented for strengthening the weakened sections of tracheal cartilages, as well as other, smaller stenosed parts of the respiratory tract.

Prior Art The prostheses with the modifications used for the implantation into the trachea according to clinical diagnostics recommendations are known (see J. Rosch et al. The Gianturco - Rosch Z Stents. Tenth International Course of Peripheral Vascular Intervention, May 18 - 21, 1999, Paris, p. 223 - 228). Such prostheses, executed as Z - shaped structures, are fastened together sectionally, mainly by a non - metallic thread. The number of such Z - shaped structures can differ, from two and more, according to the needs. It is possible to locate the prosthesis in a polymer shell. It is supposed that the prosthesis is implanted by way of pushing it through a polymer tube which is later removed, whereas the pusher - catheter keeps the prosthesis in place of its implantation into the trachea. The prosthesis, due to its spring properties, opens up to the diametrical sizes, determined by the connecting thread, fastening the prosthesis sections and forming its edges. The above described prosthesis (Fig. 1) was used in a clinical practice mainly as a device opening the natural canal in which the prosthesis is being implanted. Along side the undubital advantages of such a prosthesis, if has also its drawbacks, inherent in the very construction from which the prototype - prosthesis was formed. The general cylindrical surface of the prosthesis represents a polyhedron (on Fig. 1 a hexahedron is shown) the angles of which do not exclude the possibility of the penetration into a live tissue (hyper expansion and the threat of the tracheal inner wall breakage) that was observed in applying a number of the previous analogues. At the same time the prosthesis "rings" don't fully conform to the ring anatomical outline of the tracheal cartilages that makes the prosthesis position in the place of implantation indeterminate. Besides, the ring joining of the prosthesis constructive elements with the help of a polymer thread is ineffective. With the limiting of the tracheal sizes the prosthesis position in place of its implantation becomes indeterminate. With the increasing of the tracheal sizes the threat of the prosthesis angles penetration into its inner wall arises, that sometimes happened in the clinical practice. Fig. 1 shows schematically two - sectional prosthesis (1) being implanted into the trachea, where two Z - shaped structures (2) and (3) are joined by the polymer thread (4). For this purpose the Z -shaped formations (5, 6) have sufficiently locked openings through which the threads (4) are passed, while on the periphery the threads (8) and (9) accordingly. Position (10) marks the sufficiently sharp prosthesis polyhedron angle which presents a threat of penetration into the tracheal live tissue.

Summary of the Invention The purpose of this invention is to create a temporary metal prosthesis for strengthening the weakened ring sections of tracheal cartilages. The other purpose of this invention is the possibility of unhindered removal of prosthesis from the trachea according to clinical diagnostics recommendations. The set purpose is achieved by the fact that in the proposed Temporary Prosthesis the constructive elements are preliminary shaped in a form of two mainly similar stencils, from periodically repeating winding outlines, regulated after the tracheal cartilage rings, superimposed one on another, the said winding outlines are executed from the unlocked wire blanks of different preconditioned profile, whereas the said constructive elements stencils are specially oriented after the said winding outlines, and the prosthesis in an expanded state is formed from the semicircles of the said wire blank of stencils, united by the mechanical connections interlacing, the said semicircles are located oppositely one after the other along the prosthesis longitudinal axis, forming as a whole the ring structure of the said prosthesis which is placed between the we; kened sections of the trachea ring cartilages upon prosthetics. The proposed device for the said prosthesis removal from the trachea is executed ainly as a kind of the two rods, thin spokes, that are provided with the lateral hooks at the ends of the said spokes, whereas the said hooks, catching on the said interlacing mechanical connections of the said semicircles, ensure the possibility of winding the prosthesis into a single tourniquet, with the outward diameter less than the inner one of the trachea.

Thus, the set purpose is achieved by the fact that the metal ring prosthesis, combined with the ring cartilage of the trachea, restores the integrity of its anatomical outlines and creates the confident functioning of the respiratory tract other parts. The prosthesis longitudinal flexibility, envisaged in the design, doesn't practically limit any possible shifts of the tracheal fragments in the natural conditions of the organism viability. At the same time, if according to clinical recommendations the presence of prosthesis in the trachea becomes unnecessary, the prosthesis could be removed from the trachea with the help of a simple enough mechanical medical device.

Brief Description of the Drawings This invention is herein described with the help of examples and references to the accompanying drawings, wherein:

Fig. 1 shows schematically the two - sectional prototype - prosthesis used for the implantation into the trachea.

Fig. 2 shows fragmentarily one of the two similar constructive elements stencils of the future temporary prosthesis, according to the invention, executed from the unlocked wire blank.

Fig. 3 shows the constructive elements united stencils of the future prosthesis, according to the invention. For the depiction convenience sake, one of the said stencils is blackened. The initial stage of the future prosthesis calibration is also shown.

Fig. 4 shows schematically the finally expanded prosthesis, according to the invention, in a shape it will have in the trachea. Here are also conditionally shown two thin spokes with the hooks used for winding the prosthesis into a single tourniquet prior to its removal from the trachea.

Fig. 5 shows schematically the prosthesis cross - section and that of the trachea, where the prosthesis is inserted.

Specific Description Fig. 2 shows fragmentarily one of the future prosthesis constructive elements stencils, executed from the unlocked wire blank (11). The wire blank profile could be of different form. For example, quadrilateral, hexagonal, etc. Positions (12, 13) depict the ends of the wire blank (11). Somewhat elongated form of the ends (12, 13) is intended for folding and fastening on the mechanical connection interlacing which unites the future prosthesis semicircles between themselves. Fig. 3 shows the united stencils (14, 15) constructive elements of the future prosthesis which are introduced one into another against the stop prior to the calibration. As a result, the interlacing (16, 17) and mechanical connections are formed that keep the future semicircles: upper (14) and lower (15) between themselves and, at the same time, allowing short relative shifts of the united stencils. This, in turn, ensures the necessary longitudinal flexibility of the prosthesis. For the depiction's convenience sake the stencil (14) constructive elements are blackened. The ends (18, 19, 20, 21) of the winding wire blank are conditionally not folded on the interlacing (16, 17). In this the beginning and the end of each stencil are better seen. Here is also conditionally shown the beginning of the future prosthesis ring structure forming with the help of a gauge (22). After the completion of prosthetics calibration up to the sizes ensuring its safe delivery to the prosthesis place in the trachea, the prosthesis is conducted to the trachea with help of the conducting catheter with a balloon (the conduction catheter with a balloon aren't shown in Figs.). The balloon is expanded together with the prosthesis, thus fixing the location of the prosthesis in the trachea. After that the conductive catheter with the balloon are removed from the trachea. The medical procedure of the prosthesis insertion in the trachea is performed with the help and control of the standard bronchoscope.

Fig. 4 shows a finally expanded prosthesis (23) in a shape it will be implanted in the trachea (in Fig. 4 the trachea isn't shown). It is seen that the upper semicircles (24) and the lower ones (27) are kept fast on the mechanical connection interlacing (25, 26). The thin spokes (28, 29) with hooks (30, 31) are depicted conditionally. They are used for the prosthesis (23) removal from the trachea. For this purpose the hooks (30, 31) are superimposed on the interlacing (25, 26) of the semicircles mechanical connections upon the control of the bronchoscope, the spokes (28, 29) are being rotated, as is shown by the arrows in Fig. 4, and the prosthesis is being winded into a single tourniquet with the outward diameter less than the inner one of the trachea. Then this tourniquet with spokes (28, 29) is removed from the trachea, thus completing the medical procedure.

Fig. 5 shows schematically the cross - section (32) of the trachea with the prosthesis inserted it. Positions (33, 34) depict the oppositely located prosthesis semicircles, and position (35) the mechanical connection interlacing of the said semicircles. Thus, the proposed prosthesis has a natural (according to the trachea anatomical outline) ring structure that forms a reliable "corset" in the trachea, excludes the risk of the device constructive elements penetration into a live tissue, could be fastened reliably in the place of implantation for a long time, after which could be removed from the trachea by a relatively simple method. The proposed prosthesis could be also used for the other, smaller respiratory tract parts, thus restoring the natural viability of the organism.

Claims

What is claimed is:

1. Temporary prosthesis for insertion into the area of the weakened sections of the tracheal ring cartilages, comprising: the constructive elements, preliminary formed in a shape of two mainly similar stencils, from periodically outlines regulated after the tracheal cartilage rings, superimposed one on another, the said winding outlines are executed from the unlocked wire blank of different preconditioned profile, whereas the said stencils constructive elements are specially oriented after the said winding outlines, and the prosthesis in an expanded state is formed from the semicircles of the said wire blank of stencils, united by the mechanical connections interlacing, the said semicircles are located oppositely one after the other along the prosthesis longitudinal axis, forming as a whole the ring structure of the said prosthesis, which is placed between the said weakened sections of the trachea ring cartilages upon prosthetics.

2. The device for the prosthesis removal from the trachea as in claim 1, is executed mainly as a kind of two rods, thin spokes, that are provided with the lateral hooks at the ends of the said spokes, whereas the said hooks, catching on the said interlacing mechanical connections of the said semicircles, ensure the possibility of winding the prosthesis in to a single tourniquet with the outward diameter less than the inner one of the trachea.