AU2007331740A1

AU2007331740A1 - Tube for enteral nutrition

Info

Publication number: AU2007331740A1
Application number: AU2007331740A
Authority: AU
Inventors: Thomas Horbach; Reinhold Wolkenstorfer
Original assignee: Nutricia NV
Current assignee: Nutricia NV
Priority date: 2006-12-11
Filing date: 2007-12-05
Publication date: 2008-06-19
Anticipated expiration: 2027-12-05
Also published as: EP1935355A1; RU2009125467A; EP2099370A2; EP1935355B1; RU2463009C2; AU2007331740B2; WO2008071330A3; WO2008071330A2; PL2099370T3; PL1935355T3; NZ578314A; EP2099370B1

Description

-1 Tube for enteral feeding The invention relates to a tube for enteral feeding, in particular a PEG tube (PEG = percutaneous endoscopic gastrostomy). 5 Percutaneous endoscopic gastrostomy is the application of a feeding probe into the stomach, through the abdominal wall, with the aid of an endoscope. A gastroscope is routinely used for this purpose, i.e. a flexible optical instrument comprising a lens and an eyepiece or an electronic image transmission device. A PEG tube (also 10 termed PEG probe) is used for enteral feeding, i.e. feeding directly via the stomach/intestinal tract. A liquid, or food in liquid or thin-paste form, can be administered via the PEG tube. The PEG tube is one of the most frequently employed means for long-term enteral is feeding of patients who, owing to particular illnesses, are no longer able to take in sufficient food orally. The positioning of a PEG tube is usually effected with the aid of the so-termed filament pull-through method. In this method, the physician pushes a gastroscope 20 into the stomach via the mouth and the oesophagus. Air is blown into the stomach, causing it to distend, such that it is more easily examined. A hollow needle is then inserted through the abdominal wall, under endoscopic control, into the stomach through the abdominal wall. The hollow needle contains an inserted small plastic tube. The hollow needle is then removed and a filament is introduced into the 25 stomach through the small plastic tube that remains. This filament can then be gripped by means of a pincer, which the physician has introduced via the gastroscope. The filament, pincer and gastroscope are then drawn out via the oesophagus and the mouth. The PEG tube can then be connected to the end of the filament protruding from the mouth and, by pulling on the other end of the filament, 30 the probe is brought into the stomach via the mouth and oesophagus, and drawn partially through the abdominal wall. Plates on the PEG tube position it in relation to -2 the abdominal wall and the stomach. The protruding end of the PEG tube can then be connected to means for supplying food. Although percutaneous endoscopic gastrostomy has become established to a large 5 extent, nevertheless for a long time there has continued to be a considerable risk of infection, which can extend into the two-digit percentage range. Thus, a percentage rate of 5 - 15 % is still being reported in the year 2000 for peristaltic infection alone (C.H. L6ser, DMW 125, 805). In particular, necrosis and mycosis occur. lo Various attempts to prevent infections caused by PEG tubes are known in the prior art. Thus, surfaces that are as smooth as possible are used on the PEG tube, as are hydrophilic surfaces, as well as hydrogels, heparin and heparioid. Monoclonal antibodies are also used in the case of catheters. There are studies relating to the prevention of infections by means of antibiotics in the case of PEG. 15 However, antibiotics also have disadvantages; in particular, the antimicrobial effect can decline after just 24 hours, and the effect is not locally limited. In addition, the application spectrum is limited and the patient can develop resistance. Antibiotics are also disadvantageous in terms of cost. 20 US 2004/0220534 Al describes, in particular, a stomach probe having a wall made of a hydrophobic polymer, there being applied to an outer surface of the wall a hydrophilic polymer having an antimicrobial compound consisting of a phosphorus based glass in which a metal, in particular silver ions, is dispersed. Such a teaching 2s does not constitute subject-matter of the present invention. US 6,060,000 describes, in particular, catheters with the use of oligodynamic iontophoresis. For the purpose of achieving an antibacterial effect, silver ions are delivered into the surrounding fluid with the aid of an electric potential. The wall of 30 the catheter includes delimited regions, for example in the form of elongate strips, which contain electrodes for the purpose of generating the said electric potential.

-3 WO 95/04564 describes an enteral feeding probe having an outer surface coated with Parylene. 5 US 2001/0051669 Al describes medical equipment such as, in particular, catheters or the like, having a slip layer to reduce friction. The invention is based on the object of providing a tube for enteral feeding in which the risk of infection is reduced by simple means. 10 For this purpose, the invention provides a tube having an antiseptic and/or antimicrobial compound, which is applied to or introduced into at least selected surface regions of the tube. 15 Metal salts, in particular silver salts, that release metal ions (silver ions) are particularly suitable as a compound for this purpose. Compounds that release colloidal silver can also be used. According to a preferred development of the invention, the compound that releases 20 the metal ions or colloidal silver is in the form of so-termed nanoparticles, i.e. particles having dimensions in the nano range. The invention has the following advantages, in particular: a very broadband antimicrobial spectrum; a high level of activity against organisms and variants in very 25 small colonies; a long-lasting activity over weeks, months or even years; no induction of resistance; no stimulation of risk of thrombosis or-cytotoxicity; no alteration of the material properties of the tube plastic; in addition, low cost. According to a preferred development, the tube is not fully provided with antiseptic 30 and/or antimicrobial substance in all regions, but only in partial regions. These partial regions of the tube preferably extend in striate form, in particular in the -4 longitudinal direction of the tube, such that simple production, by means of extrusion methods, is rendered possible. A preferred development makes provision whereby the striate surface regions have a zigzag form or waved form. A uniform delivery and distribution of the metal ions is thereby promoted. Striate regions comprising s the antimicrobial compound and having a width that varies over the longitudinal extent or, also, that are arranged helically, can also be provided for this purpose. In order to enhance the possibilities for inspection, the tube can be designed, preferably, to have, in part, transparent regions that extend in the longitudinal 1o direction, for example in that its plastic material is transparent. Another preferred development of the invention provides for a Parylene coating on the surface of the tube. This Parylene coating can be provided on the outer surface and/or the inner surface of the tube. An anti-crustation layer can also be provided, 15 in addition to or as an alternative to the Parylene coating. A further preferred development of the invention provides for a tube made, for example, of polyurethane or silicone, which is provided with a Parylene coating on the outer surface and/or the inner surface, a further coating, of a material that 20 releases metal ions, being applied over the Parylene coating. The metal ions can be, for example, silver ions or titanium ions. A further coating, which releases colloidal silver, can also be provided. Preferably, Parylene C and/or Parylene N is/are used. It has been found that, for the 25 application intended here, Parylene C has a particularly good chemical resistance and a slight antibacterial effect. Parylene N, on the other hand, is distinguished by a particular slipperiness. Also suitable is a mix of Parylene C and Parylene N. The invention also relates generally to tubes for enteral feeding, in particular probes 30 and catheters, that are distinguished in that they are provided with a coating of -5 Parylene or Polyparylene, the coating containing substances that act antiseptically or antimicrobially, in particular by releasing metal ions or colloidal silver. Here likewise, as in the case of the other embodiments, in particular the PEG tube, 5 the antiseptically or antimicrobially acting substances are preferably introduced or applied in the form of nanoparticles. In the case of all the exemplary embodiments described here, the layer thickness of the Parylene coating can preferably be in the pm range, in particular in the range 10 from 0.2 to 10 pm, particularly preferably in the range from I to 5 pm. In this case, a further coating, of a material that releases Ag-ions or Ti-ions or colloidal silver, can be additionally applied to the Parylene coating already mentioned above. This applies both to the outer coating of the tube and to its inner coating. 15 Techniques for applying such coatings are known as such from other fields, for example from the general technique of metal coatings. The concentration and/or layer thickness of the antiseptically or antimicrobially acting substances that release metal ions or colloidal silver is/are preferably to be so 20 dimensioned that they are active, in particular, in the first 20 days of the application, for as long as the risk of infection exists. The tubes described here are preferably composed of polyurethane or silicone. Multilayer tubes can also be provided, for example two-layer tubes having a 25 somewhat thinner outer layer, in which or on which the antiseptically or antimicrobially acting substances are arranged, while a preferably somewhat thicker inner tube layer can be free from same. Such a multilayer tube structure can be produced easily by the extrusion method. The layer arrangement can also be the inverse of that described above. 30 -6 The invention also teaches generally the use of ionized titanium, i.e. a compound that releases titanium in ionic form, as an antiseptically or antimicrobially acting substance that releases metal ions. This use relates, in particular, to PEG tubes and, generally, to tubes for enteral feeding. 5 An exemplary embodiment of the invention is explained more fully in the following with reference to the drawing. Figures 1, 2 and 3 each show, schematically, a portion of a PEG tube. Figure 4 1o shows a section through an exemplary embodiment of a tube for enteral feeding. In the figures, components that correspond to one another or have a similar function are denoted by the same references. is Figures 1, 2 and 3 shows a short portion of a PEG tube 10 made of PU. Silver nanoparticles 14 have been introduced into selected regions 12 of the tube. The regions 20 therebetween are free from such particles. The regions 12 provided with the nanoparticles containing silver extend from the 20 outer surface 16 of the tube 10 to the inner surface 18. The concentration of nanoparticles containing silver is such that they continually deliver antibacterially acting silver ions over relatively long periods of time, in particular periods of many days, weeks or months. 25 Figure 1 shows an arrangement of the regions 12 having the added antibacterial compound, which extend helically (in the form of a helical line) around the longitudinal axis of the tube 10.

-7 According to Figure 2, the regions 12 having the added antibacterial compound extend in the longitudinal direction of the tube and have a zigzag form or waved form. 5 According to Figure 3, the corresponding regions 12 are so configured that their width varies in the longitudinal direction of the tube. The representations are schematic. In reality, the regions having the added antibacterial substance are geometrically so configured that the active metal ions are 1o delivered, to a very large degree, homogeneously by the tube, i.e. the regions carrying the compound are located so close to one another that no gaps remain in respect of the antimicrobial action. The tube 10 is provided with a coating that prevents the penetration of a polyvidon is iodine complex agent and/or the penetration of disinfectants into the tube material. Parylene, in particular, is suitable for this coating. Preferably by means of a coextrusion method, the inner surface 18 of the tube is provided with a layer that is resistant to cytostatics, such that the tube retains its 20 mechanical properties. Parylene, in particular, offers protection against cytostatics. In particular, Parylene or Polyparylene (trade name) is suitable as a coating material for the tube. Parylene is a polymer from the poly-p-xylylene families. 25 Figure 4 shows a section through an exemplary embodiment of a tube 10 for enteral feeding, in particular for PEG. A tube 10a made of polyurethane or silicone constitutes the supporting structure of the tube. Applied to the tube 10a, radially outwards, there is a layer 22 of Parylene, in particular Parylene C or Parylene N or a mix of Parylene C and Parylene N. Applied over the layer 22 there is a further layer 30 24, of an antimicrobially acting material that releases metal ions, the metal ions preferably being silver ions or titanium ions. A colloidal silver, or another -8 antimicrobially acting layer that releases colloidal metal, can also be applied instead of the layer 24 or in addition thereto. The exemplary embodiment according to Figure 4 can be complemented by the 5 application of an analogous coating on the inner surface 18 of the tube 10a, thus there is applied to the inner surface 18, firstly, a coating (analogous to the layer 22) of Parylene C and/or Parylene N, and then, upon the latter on the inside, a further coating (analogous to the coating 24) of a material that releases metal ions and/or colloidal metal. 10 In Figure 4, the layer thicknesses are not true to scale; rather, the outer layers are shown as being thicker, for the purpose of simplified representation. In the description hereinbefore and in the claims and the drawing, tubes for enteral is feeding, in particular PEG tubes, are shown in general. All described details, features and measures are suitable and applicable both for application in the case of PEG tubes and, quite generally, for application in the case of tubes for enteral feeding.

Claims

1. PEG tube having, at least on or in surface regions (12) of the tube (10), an antiseptically or antimicrobially acting compound that releases metal ions or 5 colloidal metal.

2. PEG tube according to Claim 1, characterized in that the compound is distributed homogeneously in the material of the tube (10), over its thickness. 10

3. PEG tube according to either of Claims 1 or 2, characterized in that the compound is diffusibly distributed in the material of the tube (10).

4. PEG tube according to any one of the preceding claims, characterized in that the tube (10) has a Parylene coating, in particular of Parylene N and/or 15 Parylene C.

5. PEG tube according to Claim 4, characterized in that an antimicrobially acting compound that releases metal ions is mixed into the Parylene coating, or a layer (24) of a material that releases metal ions, in particular silver ions or 20 titanium ions, is applied to the Parylene coating.

6. PEG tube according to either of Claims 4 or 5, characterized by a Parylene coating on the outer surface (16) and/or inner surface (18) of the tube (10). 25

7. PEG tube according to Claim 1, characterized in that the surface regions (12) extend in striate form in the longitudinal direction of the tube (10).

8. PEG tube according to Claim 7, characterized in that the striate surface regions (12) have a zigzag form, waved form or helical form. 30 - 10

9. PEG tube according to any one of Claims 8, 9 or 10, characterized in that the striate surface regions (12a) have a varying width.

10. PEG tube according to any one of the preceding claims, characterized in that 5 the tube (10) is at least partially transparent.

11. PEG tube according to any one of the preceding claims, characterized in that the tube (10) is at least partially opaque. 10

12. PEG tube according to any one of the preceding claims, the antiseptic and antimicrobial compound that releases metal ions being in the form of nanoparticles.

13. PEG tube according to any one of the preceding claims, made of polyurethane 15 or silicone.

14. Tube for enteral feeding, characterized by a coating comprising Parylene or Polyparylene, characterized in that an antiseptically or antimicrobially acting compound, in particular an antiseptically or antimicrobially acting compound 20 that releases metal ions, is introduced into and/or applied to the coating.

15. Tube according to Claim 14, having a coating (22) of Parylene N, or Parylene C, or a mix of Parylene N and Parylene C, and having a further coating (24) of a material that releases metal ions, in particular silver ions or titanium ions.