WO 00/54830 PCT/US00/07307 5 10 CATHETER WITH IMPROVED JUNCTION HOUSING 15 Background of the Invention This invention relates to the field of intravenous catheters, and, more 20 particularly, to an indwelling catheter that has an improved junction housing configuration that allows the catheter to be affixed to the patient in an orientation free manner and which provides enhanced patient comfort. In general, typical indwelling patient catheters are used to gain access to the 25 patient's venous system and is employed to infuse variously fluids into that patient and/or to withdraw fluids from the patient. The catheter normally includes a junction housing, particularly with the multi lumen catheters, and the junction housing facilitates communication between the plurality of inflow tubes and the single multi lumen cannula that is inserted into the patient for communicating with the venous 30 system of the patient. In the normal practice with such catheters, the indwelling multilumen cannula is inserted into the venous system of the patient by means of the Seldinger technique or other insertion means and the junction housing is then affixed to the 35 skin of the patient so the catheter can remain in place for a continuous period of time. Thus, the fluids can be administered to the patient through the multiple of inflow tubes without continually inserting and withdrawing the catheter from the venous system of the patient. For convenience, the free ends of the inflow tubes preferable have Luer fittings to aid in connecting to the various supplies of fluid or to 10 other devices. SUBSTITUTE SHEET (RULE 26) WO 00/54830 PCT/US00/07307 -2 Accordingly, the catheter junction housing is either taped to the patient's skin or preferable is sutured to that skin, in which case, the junction housing has suture openings that are used to secure the junction housing to the patient with the sutures. Obviously, the mere fact of having a catheter affixed to the patient's skin is an 5 uncomfortable circumstance and it is therefore advantageous that the attachment and the suturing of the junction housing cause a minimum of discomfort to the patient. In many such catheters, the suture openings are displaced away from the surface of the patient 's skin and thus, when the sutures are tightened, the catheter junction housing is drawn toward the skin and correspondingly, the skin is displaced 10 upwardly toward the junction housing and the suture opening in the housing. The raising or pulling of the patient's skin is relatively painful and it is advantageous to avoid such pulling. Therefore, it is preferred that the configuration of the junction housing be as nearly as possible fitted to the skin in a comfortable L5 and conforming surface. Not only is the close fitting feature more comfortable to the patient but additionally, it reduces the free space between the catheter junction housing and the patient's skin where the growth of bacteria is likely to take place. In addition, the present catheter junction housings are designed to have a o0 necessary orientation as they are sutured to the patient, that is, the configuration of current junction housings require that the housing be affixed only in one orientation and such limitation is some times inconvenient to the practitioner that is suturing the junction housing to the patient. 5 Summary of the Invention In accordance with the present invention, an indwelling catheter is provided that has a junction housing configured with a slightly convex curved surfaces so as to lie flat against the surface to the patient's skin and generally conform to the 0 normal curvature of the skin to present a comfortable orientation to the patient. As such, there is a minimum of space between the surface of the catheter junction and the skin of the patient. In addition, the catheter housing has both of its surface SUBSTITUTE SHEET (RULE 26) WO 00/54830 PCT/US00/07307 areas of a mirror image, slightly convex curved surfaces so that the junction housing may be sutured to the patient in an orientation-free manner. As such, the attending personnel can suture the junction housing to the 5 patient in either of its positions and thus is more convenient to the caregiver since the multilumen cannula can be readily inserted by conventional techniques into the venous system of the patient and the catheter need be twisted only a minimum amount to comfortably seat one of its surfaces against the skin of the patient. 10 The above and other objects of this invention will be apparent from the detailed description and drawings in which like parts are referred to by like numbers throughout. Brief Description of the Drawings 15 FIG. 1 is a front perspective view of a typical current indwelling catheter known in the prior art; FIG. 2 is a cross-sectional view of the prior art indwelling catheter of FIG. 1 20 taken along the lines 2-2 of FIG. 1; FIG. 3 is an enlarged perspective view of a junction housing for an indwelling catheter constructed in accordance with the present invention; 25 FIG. 4 is a plan view of an indwelling catheter in accordance with the present invention and showing the junction housing of FIG. 3 with a plurality of inflow tubes; FIG. 5 is a plan view of a junction housing constructed in accordance with the present invention ; 30 FIG. 6 is a side view of the junction housing of FIG. 5; FIG. 7 is an end view of the junction housing of FIG. 5. SUBSTITUTE SHEET (RULE 26) WO 00/54830 - 4 - PCT/US00/07307 Detailed Description of the Invention Referring now to FIGs. 1 and 2, there is shown, respectively, a perspective 5 view and a cross-sectional view taken along the line 2-2 of FIG 1 showing a typical prior art catheter. As can be seen, the indwelling catheter 10 comprises a housing 12 having a single cannula 14 extending outwardly from the housing 12 and which is intended to be inserted into the patient and have the distal tip 16 positioned within the venous system of the patient to infuse or withdraw fluids from that venous 0 system. Extending proximally from housing 12 is an inflow tube 18 that may include a Luer lock fitting 20 at its proximal end thereof for ready attachment to the various medical tubing that supplies fluid for introduction into the patient. As also can be seen, the housing 12 has a plurality of suture openings 22, 5 two of which are used in the preferred embodiment. In attaching the indwelling catheter 10 to the patient, the sutures are placed in the skin of the patient and then circle through each of the suture openings 22 so as to tightly affix the catheter in position on the patient. ) In the configuration of the housing, and turning specifically to FIG. 2, the lower surface is a flat surface 24 while the opposite, upper surface is a curved surface 26 that is slightly convex. In use, the flat surface 24 is intended to face the surface skin of the patient and the curved surface 26 faces away from the skin of the patient. As can be seen, therefore, it is important that the prior art indwelling catheter 12 be oriented by the user so as to be in the only proper, designed position for being sutured to the patient, that is, with the flat surface 24 facing the patient. As also seen in FIG. 2, a passageway 28 passes through the housing 12 and forms a part of the communication from the Luer fitting 20 to the distal end 16 of the indwelling catheter 10 so that fluids can be introduced into the patient through the indwelling catheter 10.
WO 00/54830 PCT/US00/07307 -5 Turning now to FIG. 3, there is shown an enlargea perspeCLIV view u, , junction housing 30 constructed in accordance with the present invention as used on an indwelling catheter 32. As shown there is a single multilumen cannula 34 that extends distally from the junction housing 30 and which contains, for example, five 5 separate lumens for delivering fluids to and/or for withdrawing fluids from the patient. Extending proximally from the junction housing 30 are a plurality of inflow tubes 36 and in the embodiment shown, there are four of the inflow tubes 36 although a greater or lesser number of the inflow tubes 36 can be used. In the catheter construction, the junction housing 30 is insert molded such that each of the inflow 10 tubes 36 is fluidly communicating with an individual lumen contained within the multilumen cannula 34. Accordingly, each inflow tube 36 can have a particular fluid introduced into the inflow tube and that fluid will pass through the catheter junction housing 30 into a specific lumen within the multilumen cannula 34 to be discharged from the distal end thereof into the venous system of the patient. 15 The outer surface 38 of the junction housing 30 is, as seen, slightly curved outwardly, that is, a slightly convex, smooth surface and thus is a surface that fits well into and conforms to the surface of the patient's skin. A pair of suture openings 40 are provided in the outer periphery of the generally circular configuration of the 0 junction housing 30. Turning now to FIG. 4, there is shown a perspective view of a portion of the indwelling catheter 32 and illustrating the plurality of inflow tubes 36 that, for convenience, have their proximal ends terminate in Luer fittings 42 to be attached to 5 other medical tubing or devices to administer or receive fluids to and from the patient. Generally, the inflow tubes may be of a polymer material to be flexible yet sufficiently strong to withstand the application. Turning finally to Figs. 5-7 there is shown, respectively, a plan view of the 0 junction housing 30, a side view of the junction housing 30 and an end view of the junction housing 30, all constructed for use in an indwelling catheter 32 in accordance with the present invention. In the FIGs., there can be seen that the outer surfaces 38 of the indwelling catheter 32 are mirror images and both are SUBSTITUTE SHEET (RULE 26) WO 00/54830 PCT/US00/07307 -6 slightly curved outwardly, or slightly convex. Thus, the outer surfaces 38 are interchangeable with respect to the positioning of the indwelling catheter on the patient, that is, therefore the indwelling catheter is orientation-free and can be sutured to the patient in either position. Thus, in the positioning of the indwelling 5 catheter in the patient, the caregiver does not have to pre-orient the catheter in any particular position since, once the multilumen cannula 34 had achieved the desired position in communication with the venous system of patient the junction housing can be immediately sutured in place without regard to whether either side is correct to face the patients skin. 0 Numerous further variations and combinations of the features discussed above can be utilized without departing from the spirit of the invention as defined by the claims below. Accordingly, the foregoing description of the preferred embodiment should be taken by way of illustration rather than by way of limitation of 5 the invention as claimed. SUBSTITUTE SHEET (RULE 26)