IMPROVED RADIOPAQUE MEDICAL TUBING

Abstract: An improved coextruded tubing (12) composition comprises a physiologically inert flexible waterproof thermoplastic material having encapsulated within the wall (14) of tubing (12) one or more strips (16) of radiopaque material coaxially disposed along the length of tubing.

Description: . IMPROVED RADIOPAQUE MEDICAL TUBING Background of the invention This invention relates generally to a radio- graphic opaque medical tube, and more specifically to catheters cannulae and other similar tubes which are intro¬ duced into the body cavity during the medical procedures. Catheters and like cylindrical tubes for intro¬ duction to the body cavity are presently manufactured of rubber, vinyl and other thermoplastic materials. Extru¬ sion of such plastic materials is widely employed because of the economies of production. Recently, such tubes have been constructed with an X-ray opaque stripe extend¬ ing throughout the length of the tube so that by direct¬ ing a beam of X-rays through the body of the patient, the relative position of the catheter will appear on the fluoroscope or X-ray film. The stripe may include any suitable X-ray opaque pigment such as one of the bismuth salts. • The list of following U.S. patents discloses a wide variety of medical tube constructions having radiopaque properties. U.S. Patent Title* Inventors Issued 2,227,682 Method of Mak¬ Ruth Wade 1/7/41 ing Striped Pellicles 2,237,221 Application of Vincent J.Flynn 4/4/41 Cellulose Deriva¬ tives 2,857,915 X-ray Catheter D. S. Sheridan 10/28/58 3,190,290 Intercostal R. D. Alley, 6/22/65 Catheters et al 3,228,894 Fluoro Carbon Norman C. Jackel 1/11/66 " Tungsten Members 3,336,918 Radiopaque. Norman C. Jackel 8/22/67 ϋrethane Coated Catheter and Method for Coating Same U.S. Patent Title Inventors Issued 3,529,633 X-ray Opaque Tub- V. L. Vaillancourt ing Having A Trans- 9/22/70 parent Stripe 3,605,750 X-ray Tip D. S. Sheridan, 9/20/71 Catheter et al 3,618,614 Nαntoxic Radio¬ Vincent J. Flynn 11/9/71 paque Multi-wall Medical Surgical Surgical Tubings 3,749,134 Radiographically Eugene . Slingluff, Opaque Plastic et al 7/31/73 Tubing 3,847,157 Medical Surgical James C. Caillouette Tube 11/12/74 4,027,659 Radiographic E. . Slingluff 6/7/77 Opaque and Conductive Striped Metal Tubes 4,105,732 Radiographic E. L. Slingluff 8/8/78 Opaque and Conductive Striped Medical Tubes French Certificate de Utilite No. 2,188,448 Composite Walled Surgical/Medical Tubing For Wound Drainage Catheters, Etc., With One Layer of Hard Material in Wall William Warne & Co. Ltd. 7/6/72 South African Patent No. 7303736 Improvements in or Relating to Tubes For Surgical and Medical Purposes" Reginald W. Harrison 3/3/75 n particular, French Certificate de Utilite No.. 2,188,448 describes a multi-layer tubing construction in which one of the materials is. radiopaque. In one em¬ bodiment the catheter may have incorporated therein- rods 5 or wires. Similarly the U.S. 3,19072W of Alley, et al discloses a catheter having a X-ray opaque line embedded longitudinally therein with the opaque line being inter¬ rupted by openings in -the catheter. Nevertheless, the prior art does not disclose-a " c " atfreter in which one or 10. more stripes of radiopaque material are totally encap¬ sulated within the catheter material, so as to prevent a contact between the radiopaque material and either liquid flowing through the catheter or the tissue sur¬ rounding the catheter upon insertion into the body of 5 the patient. Accordingly, it is an advantage of the present invention to provide an improved medical surgical tubing construction having one or more stripes of radiopaque material encapsulated therein. It is an additional 0 advantage of the present invention to provide a tubing construction in which a plurality of radiopaque stripes provides the ability to view the tubing through the x- ray equipment while at the same time permitting viewing of the flow of liquids through the tubing in those areas 5 not occupied by radiopaque stripes. Summary of the invention The present invention is particularly directed to medical tubes formed of a suitable flexible material and including .an integral stripe portion containing radio- 0 opaque material. Preferably the tubing is coextruded of a physiologically inert flexible waterproof thermo-. plastic. The material may be transparent, translucent or opaque depending on the application desired. Encapsu¬ lated and coextruded within the body of the tubing are 5 one or more stripes of radiopaque material extending longitudinally along the length of the tubing. * In an embodiment where more than one stripe is utilized, the stripes are.disposed coaxially from each other. Each stripe, preferably occupies an area not greater than 90° of the circumference of the tubing, in order to minimize- the use of radiopaque material. However, stripes of greater width are encompassed within the scope of the invention, and may extend anywhere up to 160° of the circumference αf the tubing. In one embodiment, each stripe occupies approximately 90° of the circumference of the tubing, with the stripes disposed approximately 180° from the other. In another embodiment of the invention a multi¬ plicity of radiopaque stripes are disposed within the tubing, with each stripe occupying a cross-sectional area of approximately. 45" of the circumference of the tubing. In this case, a number of stripes are utilized in order to provide sufficient radiopaque properties to the tubing. In an additional alternative, a triad of stripes equally spaced from each other and each occupying approximately * 90° of the circumference of the tubing, are disposed with- in the tubing. In one embodiment, the previously mentioned radiopaque material of which the stripes are composed, comprises between 10 and 30 percent bismuth trioxide by weight, mixed with a clear plastic material and coex- truded into the wall of the tubing. Equivalent quanti¬ ties of barium sulphate or bismuth subcarbonate may also be utilized. It is particularly important, however, that , a high concentration of" radiopaque material be contained within the stripe, in order to make it sufficiently visible under X-ray. The tubing itself may be constructed of polytetrafluoroethylene, polyfluorinated ethylene/propyl- ene, polyvinylchloride, nylon, polyethylene, polyurethane or polypropylene. Similarly the plastic material in which the radiopaque material is intermixed may also comprise any one of these materials. The above-listed catheters are preferably made by an extrusion procedure, although other commonly known manufacturing methods may be used. Thus, a multi-orifice tubular extrus on d e is f tted to a double screw extru¬ sion machine or similar device equipped with means for blowing air into the resulting extruded tube through a central opening in the die. The tubular die has a major orifice which is substantially circular in cross-section, formed between the inner wall and outer wall and also has one or more minor orifices which may be substan¬ tially circular in cross-section or any other desired shape. In extruding the tube of which the catheter is formed, the plastic material to create the tube is ex¬ truded through the. major orifice, while the X-ray opaque pigmented plastic material which form the longitudinal stripe is extruded through the minor orifice. With the possible exception of that part of the catheter which comprises the tip of the catheter, the catheter should have substantially a uniform wall thick¬ ness throughout its length. Such uniformity in wall thickness is obtained by extruding plastic material through the die in varying quantities per unit time, and at the same time, coordinating the rate of withdrawing the tube away from the die, and also introducing air '• through the die opening so that the air blowing and with¬ drawal is coordinated with the change in rate of- extru- sion of plastic material to maintain a substantially constant wall thickness. * Brief description of the drawings. FIGURE 1 of the drawings is a side view, par¬ tially broken away, of an improved radiopaque medical tubing construction. FIGURE 2 of the drawings is a cross-sectional view of an improved medical tubing showing in particular a stripe of radiopaque material encapsulated within the wall of the tubing. FIGURE 3 of the drawings is a cutaway view of the improved radiopaque medical tubing shown in ' FIGURE 1 showing in particular a pair of oppositely disposed stripes of radiopaque material each occupying a portion of the circumference of the tubing, of less than 90°. FIGURE 4 of the drawings is a cross-sectional view of an improved radiopaque medical tubing construc- tion showing in particular a triad of radiopaque stripes encapsulated within the wall of the tubing. FIGURE 5 of the drawings is a cross-sectional view of an improved radiopaque medical tubing construc¬ tion showing in particular a quartet of' stripes of radio- paque material radially disposed and encapsulated within the walls of the tubing. FIGURE 6 of the drawings is a cross-sectional view of an improved radiopaque medical tubing construc¬ tion showing in particular a single stripe of radiopaque material occupying a cross-sectional portion of approxi¬ mately 160 β of the circumference of the tubing and en¬ capsulated within the wall of the tubing. FIGURE 7 of the drawings is a cross-sectional view of an improved radiopaque medical tubing construc- tion showing in particular -sextet of radiopaque stripes, radially disposed and encapsulated within-the walls of the tubing. Detailed Description of the preferred embodiment While this invention is susceptible of embodi- ment in many different forms, there are shown in the draw¬ ings and will herein be described in detail several specific embodiments with the understanding that the present disclosure is to be considered as exemplification of the principles of the invention and ' is not intended to limit the invention to the embodiments illustrated. As best seen in FIGURE 1 of the drawings, im¬ proved medical tubing construction 10 comprises a tubular portion 12 constructed of a physiologically inert flex¬ ible waterproof thermoplastic material. Encapsulated within the wall 14 of the tubular portion 12 are stripes 16 and 18 of radiopaque material which extend coaxially along . tubular portion 12, in substantially parallel alignment with axis a-a. As best seen in FIGURES 2 and 3 of the drawings, medical tubing 12 may have a- single stripe 16 or a pair of stripes 16 and 18 disposed within the wall 14 of tubing 12. Stripes 16 and 18 occupy a cross-sectional area of less than 9 ' 0 β of the circumfer¬ ence of tubing 12 in order to provide, as best seen in FIGURE 1, visibility through the window portions 20 and 22 of tubing 12, when tubing 12 is constructed of a transparent material. This is particularly important when medical tubing 10 is used as a catheter, in that the flashback of blood may be observed through the wall of tubing 12. While the invention encompasses, the use of a single stripe such as stripe 16 seen in FIGURES 2 and 6, it is preferred, that a number of stripes, such as stripes 16 and 18 as seen in FIGURE 3 be utilized, in order to provide enhanced radiopaque properties no matter the position of the tubing 12 within the body of the patient. At the same time these considerations must be weighed against the cost of increasing the quantity of radiopaque material encapsulated within the walls of the tubing. Accordingly, a wide variety of configurations of radio¬ paque stripes encapsulated within the walls of tubing 12 may be utilized. For example, as seen in FIGURE 2, a single stripe of less than 90° of the circumference of the tubing 12 may be utilized. Alternatively, a pair of.stripes each occupying 90° or less of the circumference of tubing 12 may be seen in FIGURE 3. As seen in FIGURE 4, a triad of stripes 16, 18 and 24 may be encapsulated coaxially within tubing' 12. In FIGURE 4, stripes 16 and 18 and 24 each occupy less than 45° of the cross-sectional area of tubing 12, but combine to provide the desired degree of radiopacity. Stripes 16, 18 and 24 may be round, square rectangular or any shape required. As best seen in FIGURE 5* of the drawings, a quartet of stripes 16, 18 r - 24 and 26 may be utilized. Alternatively, as seen in FIGURE 7, a sextet of stripes 16, 18, 24, 26, 28 " and 30 may be encap¬ sulated within -the wall 14 of tubing 12. The prefecred^- ± -f- embodiment of the invention may be seen in FIGURES 1 and 3 in which a pair of radiopaque stripes are coaxially positioned 180° apart from each other. Of particular significance in the present inven¬ tion is the enhanced radiopaque properties of the stripes themselves. In order to reduce the cross-sectional area of the stripe an increased degree of loading of radiopaque material must be encapsulated within the tubing. It has been found that a mixture of between 10 and 30% by weight bismuth trioxide, barium sulphate, or bismuth subcarbonate intermixed with physiologically inert thermoplastic mater¬ ial and encapsulated within the tubing provides the desired degree of radiopacity. It has been further_ found that be¬ tween 12% and 24% of the aforementioned radiopaque mater¬ ials (bismuth trioxide or barium sulphate) by weight pro- vide optimum manufacturing and radiopaque properties. Medical tubing 12 may be constructed of such physiolog¬ ically ' inert transparent flexible waterproof thermoplastic materials as polytetrafluoroethylene, polyfluorinated ethylene/propylene, polyvinylchloride, nylon, polyethylene, polyurethane or polypropylene. However, the preferred material is polytetrafluoroethylene (Teflon®) * . The foregoing description and drawings merely explain " and illustrate the invention and invention is not so limited thereto except insofar as the appended claims are so limited as those skilled in the art who have the disclosure before them will be able to make modi ications and variations therein without departing the scope of the invention.

Claims: -9- I CLAIM: 1. An improved coextruded medical tubing construction comprising a physiologically inert flexible waterproof thermoplastic material having encapsulated therein a plurality of stripes of radiopaque material coa ially disposed about said tubing. 2. The medical tubing as described in Claim 1 in which each of said stripes of radiopaque material is disposed within a cross-sectional area of approximately 90* of the circumference of said tubing, so as to re- duce the quantity of radiopaque material required for radiopacity. 3. The medical tubing as described in Claim 1 or 2 in which said thermoplastic material is substan¬ tially transparent so as to permit the observation of the flow of liquid through said tubing between said stripes, while retaining the radiopaque properties of said tubing. 4. The medical tubing as described in Claim 1 in which ' said plurality of stripes comprises a single stripe of between 30 and 160° of the circumference of said tubing. 5. The medical tubing as described in Claim 1 in which said plurality of stripes comprise a pair of stripes each occupying approximately 90° of the circum-. ference of said tubing, said pair of stripes being op¬ positely disposed on said tubing. 6. The medical tubing as described in Claim 2 in which each of said stripes is separated from the next by a cross-sectional area of the circumference of said tubing substantially equal to or greater than the cross sectional area of said stripe. 7. The medical tubing as described in Claim 6 in which each of said pair of stripes is disposed within a cross-sectional area of approximately 45" of the circum¬ ference of said tubing. 8. The medical tubing as described in Claim 6 in which said plurality of stripes comprises a triad, each separated by a substantially equal cross-sectional area of said tubing. 9. The medical tubing as described in Claim 1 in which said plurality of stripes of radiopaque material comprises a mixture of between 6% and 30% by weight of barium sulfate to a physiologically inert filler material. 10. ' The medical tubing as described in Claim 1 in which sa-id plurality of stripes of radiopaque material comprises a mixture of between 6% and 30% by weight of bismuth trioxide to a physiologically inert filler material. 11. The medical tubing as described in Claim 1 or 2 in which said plurality of stripes of radiopaque material comprises a mixture of between 6% and 30% bis¬ muth subcarbonate by weight to a physiologically inert filler material. 12. The medical tubing as described in Claim 9 or 10 in which said physiologically inert filler material is selected from the group comprising polytetra- fluroethylene, polyfluorin ' ated ethylene-propylene -polyvinylchloride, nylon, polyethylene, polyurethane or polypropylene. 13. The medical tubing as described in Claim 1 or 2 in which said physiologically " inert flexible waterproof thermoplastic material is selected from the group comprising polytetrafluroethylene, polyfluorinated ethylene-propylene, polyvinylchloride, nylon, polyurethane, polyethylene or polypropylene.

Inventors: CHESTER B
Applicants: ABBOTT LAB
Application year: 1981
Main classification: A61M25
IPC codes: A61M25