Catheter/needle assembly kit and method for administering therapeutic agents to the subarachnoid space

A method for introducing an injectable medicament into the subarachnoid space of a patient comprising:

• introducing an epidural needle having a distal point and a bore therethrough into an epidural space of a patient until said distal point of said epidural needle is in close approximation to the dural membrane;
• advancing a catheter/needle assembly through said bore of said epidural needle, said assembly comprising an elongate flexible tube portion sized to fit within said bore of said epidural needle, said tube portion having a distal end and a hollow bore therethrough, said tube portion having a length greater than said epidural needle said assembly further comprising an elongate needle portion having a distal point and a passageway therethrough, said needle portion being fit within, fixedly attached and fluidly sealed in said hollow bore of said flexible tube, said point of said needle portion distally projecting a distance from said distal end of said flexible tube, said passageway fluidly communicative with said bore of said tube, said distal end of said flexible tube forming a shoulder projecting radially outwardly from said needle portion, until said elongate needle portion extends beyond said distal point of said epidural needle;
• penetrating the dural membrane with said needle portion so that said bore of said assembly is in fluid communication with said subarachnoid space and said shoulder contacts the dural membrane providing a resistance to penetration of said flexible tube into the subarachnoid space;
• withdrawing said epidural needle from said patient thereby leaving said catheter/needle assembly in the subarachnoid space;
• and
• introducing the medicament into the subarachnoid space of the patient through said hollow bore of said assembly.