Abstract:
An intravenous catheter has a tip portion, an extendable portion and a proximal portion attached to a hub. The extendable portion has a refracted position and an extended position. A wire may be incorporated in the intravenous portion. The wire may have a receiver disposed in the tip portion. An extender tool is insertable and removable from the catheter. The extender is dimensioned to engage the receiver upon insertion into said catheter and lengthen the extendable portion of said catheter to said extended position when inserted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/791,289 filed Mar. 15, 2013, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention is in the field of intravenous catheters, methods of using the catheters and a kit comprising the catheters. 
     BACKGROUND 
     Intravenous catheters are used for administration of intravenous medications, fluids and blood products routinely in emergency departments, hospitals and other patient care areas. Placing a peripheral venous catheter (PIV), is relatively easy in adults, but can be tedious, difficult (even for an experienced provider) and time consuming in infants and younger children as they have smaller and more fragile veins than adults and the veins are difficult to locate and stabilize while inserting and securing the catheter. 
     Once placed, it is harder to maintain the catheter in place, due to its short length, constant movement of the extremity and non-cooperation from younger children. Under the age of 5 years, the mean duration of patency of catheters is less than two days and it is shorter for infants and neonates. Maintenance of patency of these catheters is important for reducing patient discomfort and need for restarting of the PIV. Fewer IV restarts can reduce pain and anxiety to the patient and its family members; conserve supplies and professional time for any busy hospital. 
     When IV therapy is needed for a longer duration, peripherally inserted central venous catheters (PICC) are used. These catheters require provider expertise on the part of the provider, ultrasound guidance and special catheter kits and may also require fluoroscopy. PICC line placement, especially in children, is time consuming and can be associated with similar complications as central venous catheters including thrombosis, infection and bleeding. Accordingly there is an ongoing need for a catheter that can be placed by clinical providers without the need special training and will last longer than traditional IV catheters. 
     SUMMARY 
     The invention is an extendable intravenous catheter. The catheter is configured as a conventional catheter for purposes of insertion and placement. However, the catheter may be lengthened after placement to extend farther into the vessel. 
     The catheter includes a hub and an intravenous portion having fluid communication therethrough. The intravenous portion has a tip portion, an extendable portion and a proximal portion attached to the hub. The extendable portion has a retracted position and an extended position. An extender tool is insertable and removable from the catheter. The extender tool is dimensioned for passing through said hub, proximal portion and extendable portion but not through said opening in said tip portion such that said extenable portion may be extended to its extended position by inserting and applying sufficient pressure to said extender tool. 
     In another embodiment, a wire is incorporated in the intravenous portion. The wire includes a coiled portion that supports maintenance of said intravenous portion of said catheter in said extended position 
     In another embodiment, the wire has a receiver disposed in the tip portion. 
     In another embodiment, this invention is a method of inserting a catheter into a patient comprising inserting into the patient an extendable catheter of the invention wherein the extendable portion is in its retracted position, inserting the extender tool into said catheter and exerting sufficient pressure on said extender tool to extend the catheter to its full length. 
     In another embodiment, this invention is a kit comprising an extendable catheter of the invention and an extender tool. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  shows a prior art intravenous catheter. 
         FIG. 2  shows an extendable intravenous catheter of the present invention. 
         FIG. 3  shows a coiled and unwound spring. 
         FIG. 4  depicts an embodiment of the extender tool. 
         FIG. 5  is a cut away side view of an embodiment of the extendable intravenous catheter. 
         FIG. 6  is a cut away side view of an embodiment of the extendable intravenous catheter with the extender tool inserted. 
     
    
    
     DETAILED DESCRIPTION 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
       FIG. 1  shows a prior art intravenous catheter without a needle.  FIG. 2  shows an extendable intravenous catheter of the present invention  10  without a needle. The extendable intravenous catheter of the present invention  10  includes an intravenous portion  12 , which is further comprised of a tip portion  14 , an extendable portion  16  and a proximal portion  18 . The proximal portion  18  is attached to or integrally formed with a hub  20 . An entrance opening  22  in the hub  20  is in fluid communication with an outlet tip, outlet  24  because all of these portions are assembled together or integrally formed to create a continuous lumen from the hub entry to the tip outlet. This patent lumen will accommodate a needle for placement of the IV, followed by an extender to dispose the catheter in the vessel and finally throughput of fluid solutions containing therapeutic agents. 
     The extendable portion  16  has a first position which is retracted and short relative to a second position, which is extended and long. 
     In an embodiment, the intravenous portion  12  of the catheter  10  includes a wire  30 . Wire  30  has a retracted configuration  32  which is compacted in an axial direction and wound relatively tightly. The wire  30  has no memory for retaining this configuration  32 . The wire  30  may be extended to an extended position  34 , which is relatively less compacted axially, unwound and long. The metal or other material of which spring  30  is fabricated is selected for retaining the extended configuration  30  after having been placed in the extended configuration  34 . 
     As is seen in the cutaway side view of  FIG. 5 , in an embodiment of the invention, the entrance opening  22  and tip outlet  24  are in fluid communication through a patent lumen throughout the catheter  10 . The side wall  40  of the catheter  10  includes wire  30 . Wire  30  may be embedded in the side wall  40 , attached to an outer wall or an inner wall of said side wall  40  or sandwiched between laminated layers of said wall  40  as at layer  42  for example. In a preferred embodiment, the interior lumen of the catheter maintains a smooth wall. In an alternate embodiment (not shown), the wire  30  could be completely omitted, as long as the receiver  54  is sturdy enough to withstand axial force generated by the extender tool, and to maintain a lengthened position after being extended in situ. 
     As can be seen in  FIG. 4 , an extender tool  50  is provided. In the depicted embodiment, the extender tool  50  comprises a relatively stiff wire that includes a ball end  52 . Referring now to  FIG. 5 , the wire  30  includes a receiver  54 . In the depicted embodiment, the receiver  54  is a loop in the end of the wire disposed proximate to the tip outlet  24 . The receiver loop  54  is dimensioned to have a diameter smaller than ball  52  at the end of extender  50 . 
     The catheter of the invention can be constructed of any material that is biocompatible and hemocompatible. Suitable biomaterials include polytetrafluorethylene (PTFE), polyvinyl chloride (PVC), and polyurethane (PU). In an embodiment, the catheter will be constructed using PTFE because it has a greater rate of hemocompatibility than PVC or PU, as well as a longer duration period. 
     In operation, the catheter with the extendable portion  16  in its retracted position has a needle placed therein, with the point of the needle extending through the tip outlet  24 . The IV is placed in the conventional manner. Once free flow of blood is obtained indicating the presence of the needle in the lumen of the vein, the needle is withdrawn and through the outlet opening  22 , the extender  50  is placed within the catheter  10 . Appropriate pressure is placed by the operator on the extender  50  in order to place its ball end  52  against receiver  54  of wire  30  and thereafter extend wire  30  and the intravenous catheter extendable portion  16  to move it from the retracted short position to the extended long position. Thereafter, the extender  50  is withdrawn. The wire  30  maintains its extended configuration  34  and supports the catheter in retaining its long, extended configuration for its in-dwelling duration. 
     In the depicted embodiment, the wall  40  of the intravenous portion  12  of the catheter includes an accordion shape or corrugated configuration having its outer pleats substantially corresponding to the coiled portion of said wire  30 . Thus, the material of side wall  40  can contribute to the provision in the overall catheter of a first short retracted position and then an extended long position during its indwelling use. In the embodiment depicted, the wire  30  has a proximal end anchored substantially within or near said hub  20 . 
     The catheter may be manufactured in various lengths and gauges depending on its intended use. The catheter gauge will be essentially identical to that of conventional, non-extendable catheters used for a given application. Selection and placement of the extendable catheter for a given application is well within the skill of the clinical provider. Typically the catheter will be extendable to about 3 to about 5 times its unextended length. For example, in certain embodiments, the catheter may have an unextended length of up to about 1.5 inches and an extended length of up to about 4.5 to about 7.5 inches within the patient. In other embodiments, the catheter will have a fully extended length between the lengths of a peripheral IV and that of a PICC. 
     Just after birth, the average upper arm length is 4.1 inches, while at 5 years old the length is 7.5 inches. This particular invention is applicable for all ages but is particularly applicable to the younger age groups. The gauge and length of the catheter will depend on the age and size of the patient as determined by the provider. The catheter material will be biocompatible, and smooth on the outside when extended. Like a PICC, our catheter will be inserted peripherally, but it will require less training for nurses and a shorter insertion time. 
     As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.