RU2153856C2 - Device for withdrawal of foreign bodies from hollow organs - Google Patents

Abstract

FIELD: medicine; applicable in withdrawal of concrements in inoperative patients. SUBSTANCE: manipulator is provided with working part made of titanium menelide alloy and possessing superelasticity and allowing access to especially narrow and pathologically twisting bilary ducts. EFFECT: higher efficiency. 4 cl, 2 dwg

Description

 The present invention relates to medicine, namely to surgery of hollow tubular organs of a person.

 Inflammatory processes caused by calculi of the bile and urinary tract are accompanied by significant pain and require surgical intervention.

 One of the methods of treating such patients is the extraction of calculi using various types of traps (Pashkovsky extractor - A.S. N 240373, trapping baskets combined with Dilators - A.S. NN 350465, 1673084, etc.). These traps have common drawbacks - they are all made of stainless steel, which limits their scope and durability. In addition, the well-known trap designs do not solve all the problems associated with the frequently encountered difficulty of access and capture by calculus, for example, in very narrow ducts, where there is not enough space for the deployment of known types of traps. Under these conditions, it is promising to use traps based on the effect of superelasticity of the TiNi (nitinol) alloy.

Two types of traps made of TiNi alloys are known (A.S. N 1673084, 1812972). In the first case, the extractor with a wire working tip in the form of a loop from a TiNi alloy has a zero angle and is convenient for insertion into the ureter. To bring the tip into working condition, heat ≈ 45-50 ^o C is supplied to it in the form of physiological saline or electrical pulses. In the second case (AS No. 1812972), the apparatus for removing foreign objects is a rather bulky device, in which 4-6 jaw-basket traps are made of Ti-Ni wire coated with fluoroplastic. The shape of the traps is controlled by a unit made in the form of a power source with an adjustable frequency and duration of pulses.

 The need to supply heat to the working elements of nitinol traps, and in the second case, cumbersome and high cost is a serious drawback, limiting their use.

 The objective of the invention is to create the optimal design of the trap from a biologically inert material that has superelasticity and does not require special heating, which allows to solve the problem of extracting stones from very narrow and pathologically convoluted ducts, where there is not enough space for the deployment of all other types of traps. This goal is achieved in that the trap type "Trawl" is made in the form of a structure (Fig. 1), consisting of the actual working part 1, introduced into the cavity, a manipulator 2, which allows you to control the working part, and a catheter 3.

 The working part 1 of the trap consists of two different thickness branches - axial 4 (Fig. 2) and helical 5 made of titanium nickelide wire with superelasticity. Both branches at the distal end of the structure are fixed by a sleeve.

 The axial jaw of the trap is made of wire with a diameter of 0.45-0.60 mm, and the other, helical jaw is made of wire with a diameter of 0.25-0.30 mm.

 The axial jaw 4 of the trap 1 is located inside the cone, formed by a twisted jaw 5.

 Both branches are connected to the keys 7 and 8 (Fig. 1) of the manipulator inside the catheter 3. Both branches have the ability to move inside the catheter, which allows you to control the branches separately and simultaneously by moving the keys. The key can be made, for example, in the form of a screw with a through hole in the working part with a nut screwed onto it. The end of the jaw can be fixed, for example, in the screw hole with a nut, or it can be sealed in this hole. The technique of using a trap of the “Tral” type involves the following sequence of manipulations: the working part of the trap 1 (Fig. 1) is pulled into the catheter 3 using the manipulator 2 and is inserted into the bile duct through a puncture hole under x-ray control. When both branches are removed from the catheter, the structure restores its original shape due to the effect of superelasticity. Using the manipulator, pulling the axial jaw 4 (Fig. 2) provides pulling and compression along the axis of the helical jaw 5, which wraps and pulls up the calculus, preventing it from slipping between the turns into the duct. By moving the entire trap, the calculus is extracted to the outside. If necessary, the release of the calculus is carried out by feeding forward and stretching the screw jaw. Reliability of the structure is determined by the stiffness of the axial and superelasticity of the helical jaws.

 The working part of the trap is made on a special mandrel, the shape of which the structure retains exactly after heat treatment for superelasticity.

 The selected interval of the diameter of the wire of the power rod of 0.45 - 0.6 mm due to the fact that the wire of this section provides the required rigidity of the working part of the trap when it is ejected from the catheter. When using a wire of a smaller diameter, the design does not have the necessary rigidity, and the use of a wire with a diameter of more than 0.5 mm is impractical, because an increase in diameter leads to an increase in the invasiveness of the operation and a decrease in the flexibility of the rod.

 The selected interval of the diameter of the wire of the screw jaws of 0.25-0.30 mm is due to the fact that the wire of this section provides the required rigidity of the screw jaws when gripping and pulling and moving the calculus. When using a wire of a smaller cross section, the design does not have the necessary rigidity, and the use of a wire of a larger cross section is also impractical due to an increase in the invasiveness of the operation and the deterioration of the conditions for the realization of superelasticity.

Consumer properties of the object of the invention:
- in the pathology of the biliary tract (cholelithiasis, acute calculous cholecystitis, choledecholithiasis), the use of the proposed trap design allows access to particularly narrow and pathologically convoluted bile ducts and evacuation of stones in patients inoperable due to the severity of the condition;
- if necessary, the release of calculus device design features make it easy to implement;
- the creation of a new design of the trap increases the arsenal of surgical instruments for laparoscopic operations.

Claims (4)

 1. A device for removing foreign bodies from hollow organs, containing a working part of titanium nickelide having superelasticity connected to a catheter, and their control mechanism, characterized in that the working part is made of two branches, of different thicknesses, one of which is axial, and the other is screw-shaped, while the control mechanism is made in the form of a manipulator that allows you to manage branches separately and simultaneously by moving the keys on it.  2. The device according to claim 1, characterized in that the axial jaw of the working part is made of titanium nickelide wire with a diameter of 0.45-0.60 mm, and the helical jaw is made of titanium nickelide wire with a diameter of 0.25-0.30 mm.  3. The device according to claim 1, characterized in that the helical jaw of the working part is formed in such a way that it forms a cone frame with a vertex at the distal end, while the axial jaw is located inside the cone formed by the helical jaw.  4. The device according to claims 1 and 2, characterized in that at the distal end both branches are fixed by a sleeve.

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