RU1813000C - Method and device for manufacturing microcatheters - Google Patents

Abstract

The task is to simplify the manufacture of microcatheters by reducing operations and transitions, improve their quality and manufacture on one device. SUMMARY OF THE INVENTION: A method involving plastic deformation of a tubular billet by drawing through a die, wherein the tubular billet is pre-tensioned with a reduction in diameter and cut in the middle part at an acute angle to the longitudinal axis of the billet, one of which is inserted into the die with a pointed end whose diameter is equal to the outer diameter of the working part of the microcatheter. Then, a mandrel with a diameter equal to the inner diameter of the working part of the microcatheter is inserted into the preform, and the preform is pulled together with the mandrel to a length greater than the length of the working part of the microcatheter, then the mandrel is moved inside the preform, after which the workpiece is cut off at the end of the mandrel, then the mandrel is withdrawn. and the workpiece at the end of the mandrel is again cut. Microcatheters are made using a device containing a bed, on which a working body is mounted, made in the form of a drawing board, each die of which is mounted against a handle located on the body, on which the front marking mechanism of the microcatheter's working length is installed, and the clamp is installed on the back. 2 s, and 1 s.p. of f-ly, 2 ill., 1 tab. THX

Description

The invention relates to medicine, in particular to methods for the manufacture of microcatheters used, for example, for the implementation of endolymphatic chemotherapy with repeated administration of drugs to peripheral lymphatic vessels.

The objective of the invention is to simplify the manufacture of the microcatheter by reducing the number of operations and transitions and perform them on one device, improving the quality of the microcatheter by obtaining in this way the correct shape and atraumatic surface of the working end.

In FIG. 1 shows the operations of the steps of manufacturing microcatheters; Figure 2 shows a device for the manufacture of catheters.

The device comprises a housing 1, on which a drawing board 2 is mounted, having dies 3, against which streams are mounted in the housing 4. In the front part of the housing 1, a mechanism for marking the working length of the catheter is installed, made in the form of a movable carriage 5, and in the back of the housing 1 is fixed clamp 6.

The essence of the proposed method for the manufacture of microcatheters is as follows: a polyethylene tube dizso

d

so o o o o

s

With a meter of 1-1.5 mm, a length of 20 cm, they are preliminarily (manually) extended as much as possible, while reducing its diameter. The initial elongated tube is cut in the middle part at an acute angle to the axis into two blanks. The pointed end of the preform is inserted into. corresponding to spinneret 3 (Fig. 1a) and a wire mandrin (mandrel) with a diameter necessary to form a microcatheter of the desired caliber is inserted into the tube. The tube is pulled together with the wire mandrel (mandrel) to the mark mounted by the carriage 5 on the surface of the device (Fig. 16), which determines the working length of the microcatheter.

Then, the wire mandrin is partially withdrawn from the working end of the microcatheter from the reference mark applied to the housing 1 by the movable carriage 5, and the defective end of the microcatheter is cut with a blade at an angle of 90 ° to the axis of the latter (Fig. 1c). Again, the wire mandrel (mandrel) is carried out beyond the end face from the cutting side (Fig. 1 g) and the free, non-working end of the tube is freed from the mandrel (mandrel). At the control mark 5 fixed by a clamp of the total length, the excess workpiece tube is cut off. Together with a wire mandrel (mandrel) extending beyond the working end of the tube, a microcatheter of a given size is removed from the die (Fig. 1e).

This eliminates the oval deformation in the working part of the microcatheter that occurred during the cut, sharp edges (burrs) are smoothed out. The microcatheter along the entire length acquires the correct cylindrical shape. In the manufacture of a microcatheter by the proposed method, the tube is uniformly deformed on both the outer and inner surfaces, and the cold pulling of the tube through the die retains its original elasticity.

The microcatheters made by the proposed method not only meet the requirements defining its caliber, i.e. the diameter of the working part of the atraumatic end, but also the total length of the entire catheter, which allows to normalize their sizes, in addition, the working part of microcatheters of different diameters can be made. The table provides a description of the effect of the known and proposed methods for the manufacture of microcatheters on quality of lymphatic infusion.

As can be seen from the table, when using the proposed method for the manufacture of microcatheters, the number of complications is reduced by 19 times and practically does not occur. By blocking or thrombosis of the catheter and having the same length of microcatheters and mandrin, this complication can be eliminated.

5 Thus, the practical application of the microcatheters made by the proposed method has shown that they do not injure the vessel walls at the time of catheterization. In addition, it was noted that micro0 catheters with regular cylindrical shape and uniform deformation are less susceptible to clogging with drug crystals during infusion: they significantly reduce the likelihood of damage to the lymphatic vessel when the catheter is in the lymphatic vessel for a long time, especially in the active position of patients, which increases the duration of treatment and reduces the percentage of complications.

The manufacture of microcatheters of the same size makes it possible to normalize the size type and wire mandrels accordingly, which makes it possible

5 restoration of patency of microcatheters when they are blocked without risk of damage to the catheterized lymphatic vessel, which also prolongs the duration of infusion therapy. The foregoing is supported by clinical trials.

Claims (3)

1. A method of manufacturing microcatheters, which involves the plastic deformation of a tubular workpiece by drawing 5 through a die, characterized in that the tubular billet is pre-tensioned to reduce the diameter and cut in the middle part at an acute angle to the longitudinal axis into two blanks, one of which is inserted with a pointed end into a die with a diameter equal to the outer diameter of the working parts of the microcatheter, then a mandrel with a diameter equal to the inner 5 to the diameter of the working part of the microcatheter, and pulling the workpiece together with the mandrel to a length greater than the length of the working part of the microcatheter, then the mandrel is moved inside the workpiece so that the length of the part of the guide placed in the working part of the workpiece is equal to the length of the working part of the microcatheter, after whereupon the workpiece is cut off at the end of the mandrel, then the mandrel is brought out beyond the limits of the trimmed working end 5 so that the length of the mandrel portion placed in the preform is equal to the total length of the microcatheter, and the blank is again cut off at the end of the mandrel. 2. Device for the manufacture of micro-catheters containing a housing on which a working body for drawing is placed, which means that the working body is made in the form of a drawing board with dies and arms, each die being placed against the handle, and the body is equipped in front with a mechanism for marking the working length of the microcatheter and a clamp in the back . 3. The device according to claim 2. characterized in that the mechanism for marking the working length of the catheter is made in the form of a movable carriage. and so on / tn / t: f o.crmeir Cf 4 # CTAfg / 7 W 0fnpe3t: cs S