1. Field of the Invention
The present invention is directed toward an improved catheter introducer needle for continuous perineural infusion allowing the introduction of a catheter into a body at a deflection angle in the range of 30-75xc2x0 from the axis of the needle. This invention provides for a continuous perineural placement of a catheter. The present invention is also directed toward an introducer needle/catheter system comprising the needle of the present invention and a catheter extending through the needle such that it extends out beyond the tip of the needle at an angle of deflection in the range of 30-75xc2x0 from the axis defined by the catheter within the main channel of the needle. This invention is useful in delivering pharmacological agents, such as local anesthetics, to nerves in various regions of the body including, but not limited to, the neck, arms, shoulders, back, thigh and legs.
2. Description of the Prior Art
Needles are used in the prior art to place catheters into the body. Prior art introducer needles allow a catheter to be displaced at an angle of either 0xc2x0 or 90xc2x0 to the longitudinal axis of the needle, as shown in FIGS. 1A and 1B, respectively. The 90xc2x0 displacement is achieved with prior art needles, such as the tuhoy needle, used for epidural applications.
The angular displacement of catheters which are implanted using prior art introducer needles are greatly inappropriate in view of the common geometric relationships between the tip of the introducer needle and the position of various nerves within the body of a patient. The term xe2x80x9cpatient,xe2x80x9d as used herein, encompasses human beings and animals. Very few nerves within a patient""s body are displaced parallel or perpendicular to the surface of the body. It is ideal for the portion of the catheter which extends beyond the introducer needle to be in substantially parallel alignment with the nerve which one desires to treat by injection of drugs through the catheter. The closer the catheter is aligned with the nerve, the greater is the efficiency of drug delivery through the catheter to treat the nerve. For most nerves in the body which are not displaced parallel or perpendicular to the surface of the body, prior art introducer needles do not position a catheter in closer alignment with those nerves, as shown in FIG. 3A.
Many drugs which are delivered for anesthesia purposes are toxic. The inefficiency of prior art introducer needles results in increased probability of patient toxicity poisoning resulting from the dispersion of drugs which are not delivered directly to the nerve to be treated.
The present invention is directed to an improved catheter introducer needle which is capable of more closely aligning a catheter with a nerve inside a body than prior art introducer needles. The needle of the present invention results in increased efficiency of drug delivery to a nerve, thereby reducing the volume of drugs which must be delivered. This reduction in drug dosage reduces the probability of patient toxicity poisoning. The present invention is particularly well suited to home health care applications where reducing the volume of toxic drugs delivered to the patient is highly desirable.
The introducer needle of the present invention comprises a tubular body comprising an exterior surface, an interior surface, a first end region, and a second end region. The introducer needle further comprises a channel extending the length of the body to define a channel axis and a first opening located in the first end region contiguous with the channel. The introducer needle may be connected to a tubing.
The introducer needle further comprises a second opening located in the second end region of the body contiguous with the channel. The second opening is positioned such that a flexible catheter extending through the channel and the second opening is deflected at an angle in the range of 30-75xc2x0 from the channel axis.
The present invention is also directed toward an introducer needle/catheter system comprising an introducer needle as described above and further comprising a flexible catheter extending through the channel, first opening and second opening of the body such that the portion of the catheter that extends beyond the second opening is displaced at an angle in the range of 30-75xc2x0 with respect to the portion of the catheter in the channel.