DE2313899A1 - Catheter comprising two bonded tubes - with latex tube stuck to parallel water-permeable tube - Google Patents

Abstract

A rod and wire are coated and dried. The rod is then coated with latex and the wire is coated with a film of greater water diffusion rate and only partly dried so that it can be bonded to the coated rod. The assembly is dipped in latex and dried. One end of the wire is cut, a balloon is placed over one end of the catheter and joined on by repeated coatings of lates, the assembly is soaked in warm water and finally the rod and wire are removed.

Description

Method of Making a Two-Tube Catheter The Invention relates to the manufacture of catheters and, more particularly, to a method for making catheters with a pair of parallel # tubes or lumens, for example inflatable catheters.

Inflatable catheters that have a drainage tube and a blow tube are included in practice, usually using an anode immersion technique produced in which a molded body is immersed in liquid latex. Of the Shaped body comprises a rod forming the discharge pipes and one the blowpipe forming wire, which are held together by a hinge. The molding bar and the shaped wire of the shaped body are mixed with a slurry of diatomaceous earth and calcium nitrate coated in latex before first immersion. The molding rod and the molding wire will parallel to each other at a distance through the shaped body during of the first immersion.

There are several problems that arise from the initial anode immersion the usual process for manufacturing inflatable catheters.

It was difficult or impossible to get an even deposition of Latex on the forming wire due to the differences in calcium content on the surface of the wire. Fluctuations in latex quality cause fluctuations in the total amount of latex deposited on the forming wire. Accordingly, the thickness of the latex film deposited on the surface of the forming wire is a conventional one Procedures vary between 0.1 to 0.17 mm after the latex has dried. The upper Part of the thickness range can be used to manufacture catheters with flat outer surfaces Surfaces and a substantially oval cross-section lead. The deposit only a thin latex layer on the forming wire is used in the art # as the reason for considered the non-deflation of inflatable catheters.

It is essential that inflatable catheters be deflatable or inflatable to allow removal from the body. After the end of an inflatable Catheter has been inserted into a body cavity, a balloon is nearby the end of the catheter is inflated with a fluid.

The inflated balloon holds the catheter in the body cavity and to remove the catheter from the body it is necessary to deflate the balloon. This evacuation is accomplished by draining the fluid from the balloon through the inflation tube evidenced. If for some reason it becomes impossible to use the Inflation of the balloon to enable via the inflation tube surgical intervention is necessary. All known surgical interventions for Emptying the balloon of an indwelling catheter is painful for the patient. It is therefore important that inflatable catheters have a foolproof drainage facility are provided.

The wall surface of an inflatable catheter with a drainage tube and an inflation tube is particularly important in order to obtain the desired 10% possibility of emptying za create. It has been found that the step of compressing two latex films together as is the case with the usual process for the manufacture of inflatable catheters of the Case is. microscopic flaws between the two flaws and in the vertex the two gaps formed by the contact between the two tubular latex films, can lead. These defects can preferably absorb large amounts of water. The absorption of water at these imperfections can cause a bubble or peeling of the two films and cause clogging of the blow-out tube. Such Blockage can result in a non-drainable catheter.

The invention. provides an improved method for creating a two-tube catheter or two-lumen catheter available, for example for the manufacture of an inflatable catheter with an evacuation tube and a Second (inflation) tube. 8 such procedures are used to create a drainage tube forming rod and another tube forming wire coated to a pair To form tubular parts, whereupon the tubular parts are essentially parallel connected to each other in abutment and the connected parts coated with rubber to get a smooth outer surface. The by the present Improvement made in accordance with the invention the following steps: The Application of a film from an aqueous, film-forming adhesive mixture directly onto the wire that forms the second tube, which after drying is a water-permeable Forms film the thickness of which does not exceed 0.028 mm; the drying of this film around a thin sticky tubular body on the wire forming the tube to build; and pressing the thin sticky tubular body in adherent Contact parallel to the tubular film against this, which was previously on the the drainage tube forming rod was applied by coating.

The present invention essentially avoids either Fluid barriers that are used in inflation catheters in conventionally manufactured the wall between the tubes. The presence of only a single one Barrier layer avoids the possibility of blistering and peeling of adjacent ones Layers, which is possible with a two-layer structure. This is why the possibility of clogging of the inflation tube largely diminishes, which leads to a non-drainable catheter. Defects and pores in the crevices between the shaping rod and the shaping wire are not more significant than after Removal of the wire forming the inflation tube is only one result, and although that the inflation tube has a slightly larger cross-section at the point which is permeable to the fluid within the inflation tube.

In addition, the round catheter that passes through the present method is formed by the concentric arrangement of an inflation balloon on the catheter shaft. This is due to the latex dipping process during completion Deposited latex securing the balloon to the catheter shaft is uniform deposited.

The slight uneven absorption of latex on a non-circular catheter shaft, which is produced according to the known method and to an inclined arrangement leads from balloons, d. H. an off-center arrangement of the balloons with respect to the Catheter shaft was avoided.

The invention is explained in more detail with reference to the drawing, in which a Embodiment is shown. In this drawing shows: Fig. 1 is lower End of a tube forming rod and an unconnected tube forming rod Wire, partially cut; Fig. 2 is a section along the line 2-2 in Fig. 1; 3 is a partially sectioned view of the lower end of a coated one Form rod and a coated form wire according to FIG. 1, which are parallel to each other touching each other lying down; Fig. 4 is a section along the line 4-4 in Fig. 3; Fig. 5 a partially sectioned view of the lower end of a partially molded one Inflation catheter after the completion of the latex immersion, resulting in an essentially round surface of the catheter leads; and FIG. 6 is a section along line 6-6 in Fig. 5.

The invention provides improvements in a method of manufacturing a two-lumen catheter or two-tube catheter, in which one is the drainage tube forming rod and a further tube forming wire are coated to to form a pair of tubular parts. Then the tubular parts are usually dried and then connected lying parallel to each other. The connected one tubular parts are layers with / number of rubber, for example by immersion coated to form a uniform surface. Such procedures are at the manufacture of inflatable catheters widely used in which the second Tube is a small diameter inflation tube that has an expandable Pouch or balloon.

According to the invention, a tubular latex body is on a die Drainage tube-forming rod is formed and an aqueous adhesive mixture is applied directly applied to a wire forming a second tube.

The formation of the continuous tubular latex body on the the rod forming the discharge tube can be made in accordance with the usual anode-latex deposition process are made, which is usually used in the manufacture of catheters comes. In such a method, the metal molding rod first coated with a slurry of diatomaceous earth and calcium nitrate before they is immersed in latex for the first time. By dipping in latex is preferred created a film with a dry thickness of 0.254 to 0.381 mm.

The continuous latex film is dried, for example, by that the latex coated, the drainage tube forming molding rod by a Oven is performed, which has a temperature between 34.60C 'and 51.30C.

The dried latex film on the forming rod forming the drainage tube is desirably dipped in a latex adhesive or the latex adhesive is sprayed to create a latex adhesive layer less than 0.0254 mm. The latex adhesive can be a mixture of the same Parts made of rubber latex and resin solution or rubber latex and resin emulsion. The application of glue on The dried latex film is desirable but not required for retention of the dried latex film and the adhesive mixture that is applied to the the wire forming the blowpipe is deposited, which is described in more detail below will.

According to the invention, an aqueous adhesive mixture is applied directly to the The tube-shaped molding wire is applied to a thin water-permeable film to produce on the forming wire. The thickness of this film should be after the application not more than 0.0381 mm and preferably between 0.01 and 0.0254 mm, The film of the adhesive mixture can be formed by a number of coating techniques such as B.

Spraying, dipping or mechanical application.

The aqueous adhesive mixture must be one that will dry after drying a water-permeable tubular body on the wire forming the blowpipe form. The term "water permeable" used in the description and claims used refers to the ability of water through a unit area of the adhesive film to pass through at a greater speed than this the unit area of a latex film of comparable thickness and under the same conditions the case is.

The thin layer of adhesive should be able to after a partial Dry to form a sticky surface covering the thin tubular body sticks to the latex-coated molding rod on the bare molding wire that previously was gummed in the usual way. The adhesive mix should at least have some of the adhesive properties during normal Manufacture of the catheter and during post-treatment lose in order to pull the catheter off the forming wire can.

It has been found that adhesive mixtures comprising starch and latex have a satisfactory initial tack and good peeling results and are water-permeable Allow tubular bodies to be produced which provide blowpipes which essentially are free from constipation problems. Such starch latex adhesives preferably have 5 to 15 weight percent starch and 7.5 to 75 weight percent latex on a solids basis. The starch can be U.S.P. starch, an oxidized starch such as those under the trade name "Fibersize" from National Starch & Cehmical Corp. is sold or one Acid converted starch, as sold under the trade name "Flogel 90" the National Starch & Chemical Corp.

on sale is.

The preferred starch-latex adhesive mixture contains a small amount from 0.001 to 0.04 wt. ## of an enzyme.

The enzyme helps increase the viscosity of the starch built up Glue control and can be used to help remove starch from inside the tube wall during the usual leaching step to cause which is carried out after the catheter from the metal rods or metal wires removed on which it is manufactured. The aqueous leaching step is usually at an acidic pH and at a temperature above 23.50 carried out. These conditions and the presence of Ca ++ ions contribute to the enzymatic digestion of starch.

It is currently preferred to use an adhesive for the film a bare metallic shaped wire by dipping the bare shaped wire into the adhesive mixture to raise. The viscosity of the adhesive is preferable for the immersion process 700 to 1200 centipoise, as shown with the Brookfield 7 discosimeter, model LVF 6 RPM was measured using the # 2 spindle.

Other suitable aqueous adhesive mixtures used in the manufacture of water permeable: films according to the invention can be used Latex with corn starch that is converted with acetic anhydride and under named Flozyme 3008 from National Starch & Chemical Corp. sold will.

Application by spraying the starch-rubber-adhesive mixture can can also be used to apply the mixture to the forming wire. at using a spray technique, starch-rubber mixtures with viscosities in of the order of 30,000 cps and more can be used.

The adhesive film on the forming wire forming a tube is dried, around a thin sticky water-permeable tubular body on the forming wire to form, which forms the blowpipe. Drying can be done by the tubular body is exposed to room temperature for 10 to 45 minutes or by having warm air with temperatures of 34.60C to 5E ', 80C for a Duration of 30 to 90 seconds circulates.

The sticky film on the wire forming the blowpipe becomes tight Contact with the tubular latex body and pressed parallel to this, the is on the wire forming the drainage tube. This pressure effect can from Can be carried out by hand or using a wide variety of tools, which have been developed for pressing two common latex-coated tubes.

In general, the tubular shape formed from the adhesive mixture tends to be Body for easy sticking to the latex-coated stick.

After the sticky tubular glue body and the tubular Latex bodies have been connected to one another, the catheter is connected by a standard Coating processes, such as. B. by immersion, built to a uniform to form outer wall surface for the shaft of the catheter. Following the Dipping processes follow finishing operations that include attaching a balloon or expandable pouch and cutting and separating Include openings that are carried out in a conventional manner.

Preferably, the catheters, if a starch-containing adhesive base to which an enzyme is added is used in an aqueous leaching step Subject to temperatures above 55.50. The pH of the leach medium is preferred kept at acidic levels to reveal the strength of the wall of the Accelerate tube forming forming wire.

The following example is made with reference to the drawing explained. All percentages given in the description and claims are percentages by weight, unless otherwise indicated.

The adhesive mix contains 18% latex and approximately 10% oxidized starch on a dry solids basis. The starch comes in about 56 parts of water cooked to the point of solubility and then mixed with latex.

Already before using the adhesive mixture 0.02 Parts of enzyme sold by the Marshal under the name Tilezyme Tenaset ' Division of Mildes Laboratories, Inc., added to adhesive mix - By reference In Fig. 1, the adhesive mixture is applied directly to a bare shaped wire 10 by dipping of the metallic wire formed into the adhesive mixture. The immersion process leads to an adhesive film directly on the forming wire 10.

The adhesive film is made by circulating air at a temperature of 12.40C and a humidity of up to 50% for 10 minutes. Of the The drying process results in a sticky tubular body 12 having a thickness from 0.0127 mm to 0.0381 mm.

A latex film 14 that dries to a thickness of approximately 0.3048 mm, is on a shape rod 16 forming the drainage tube using a conventional one Anode immersion technique has been applied, with the diatomaceous earth and calcium nitrate on the rod 16 can be applied prior to dipping in latex.

The latex film is solidified and then dried. On that is, as shown in Figs. 3 and 4, the tubular body 12 against the tubular latex body 14 pressed parallel to this, while this tubular Bodies are still on the form wire 10 and the form rod 16.

After the tubular body 12 is attached to the tubular latex body 14 is glued on, this assembly is repeatedly dipped in latex to form layers of latex 12 and 20 to be applied, as shown in Fig. 5 and, which have more and more circular cross-sections.

According to the usual procedure, after the immersion hole To build up the cross-section, the latex coating is dried and then a opening, not shown, cut at the end of the shaped wire 10, which the interior of the tubular #drpers 12 in connection with the outer latex layer 20 according to the Removal of the forming wire 10 brings. A balloon (not shown) is then over the distal end of the catheter striped and arranged so that the interior de + allons is connected to the opening described above.

The balloon is then passed through the distal end of the catheter Application of several layers of latex attached.

The catheters are then dried and cured in an oven and then leached in 68-73.50C water for 3/4 to 1 hour. The leaching step causes at least part of the starch to be broken down in the tubular body 12. The opening up of the starch makes the tubular Body 12. even more permeable to water. After the leaching step, the catheters are withdrawn from the shaping wire 10 and the shaping rod 16 and for further treatment bundled as usual.

Over 8500 catheters being used according to the present procedure a bare metal wire are subjected to rigorous use tests has been subjected to immersion in water. None of the over 8500 catheters tested has due to blistering or peeling in the wall between the tubes fails when blowing off.

It usually occurs with inflatable catheters designed according to the hitherto customary processes were produced and in which both tubes were produced simultaneously Immersion in latex was produced, an error due to blistering or Detachment phenomena per 1000 catheters, which are subjected to a strict usage test will.

The new method according to the invention seems to be the possibility of one Plate formation or a bleeding in the wall between the tubes is completely eliminated to have.

Claims (10)

Expectations Method of making a catheter with a drainage tube or drainage lumen and a second tube or lumen in which one 'die.die Lead tube forming rod and another tube forming wire coated to form a pair of tubular parts, whereupon the tubular parts in the essentially parallel butting together and the connected Parts are coated with rubber to obtain a smooth outer surface, g e k e n n n n z e i c h n e t, by a) the formation of a continuous latex tube part (14) on the rod (16) forming the discharge tube, b) the application of a thin water-permeable film (12) of an aqueous adhesive mixture directly the wire (10) forming the further tube; c) drying the film to one water-permeable tubular body (12) on which another tube forming Wire (10); and d) pressing the thin water-permeable tubular body (12) in an adhesive contact in a parallel position against the latex tube part (14) on the rod (16) forming the drainage tube. 2. The method according to claim 1, characterized in that the adhesive mixture (5 to 15 wt. Starch and 7.5 to 25 wt. Contains latex on a solid basisj5. 3. The method according to claim 2, characterized in that the additional Tube forming wire (10) is a metal wire and that an adhesive film (12) on the bare wire (10) by dipping the bare shaped wire is applied in an aqueous, starch-containing adhesive mixture. 4. The method according to claim 3, characterized in that the viscosity of the aqueous starch glue is 700 to 1200 cps during the dipping step. 5. The method according to claim 2, characterized in that the aqueous Adhesive mixture is sprayed onto the forming wire (10) forming the tube. 6. The method according to any one of claims 1 to 5, characterized in that that the aqueous adhesive mixture prior to application on the forming wire forming the tube (10) an enzyme is added. 7. The method according to claim 6, characterized in that the proportion of the enzyme is 0.001 to 0.04 wt. 8. The method according to any one of claims 1 to 7, characterized in that that the forming wire (10) forming the tube is a metal wire and that a continuous one Adhesive film on the bare shaped wire by dipping the bare shaped wire into an aqueous, starch-containing adhesive mixture is applied. 9. The method according to one of claims 1 to 8, characterized in that that the thickness of the film applied to the forming wire (10) is less than 0.0381 mm. 10. The method according to any one of claims 1 to 9, characterized in, that the interconnected tubular films (12, 14) after they have been covered with rubber (18, 20) are coated in order to obtain a smooth outer surface, an aqueous one Leaching step are subjected to the acidic pH range and at temperatures above 23> 50C is done to the strength on the inner wall surface of the forming wire (10) #zu digging up the tube (12).