Hollow Curved Superelastic Medical Needle And Method

Abstract

A needle assembly 10 compromising an infusion needle 11 that includes a needle cannula 13 made of a superelastic material such as Nitinol. The needle cannula is cold-worked or heat annealed to produce a preformed bend 16 that can be straightened within passageway 21 of a coaxial outer cannula 12 for introduction into the body of a patient. Upon deployment from the outer cannula, the needle cannula substantially returns to the preformed configuration for the introduction or extraction of materials at areas lateral to the entry path of the needle assembly. The needle assembly can compromise a plurality of needle cannulae than can be variably arranged or configured for attaining a desired infusion pattern.

1 - 21 . (canceled) 
     
     
         22 . A method of infusing fluid into a tumor comprising:
 providing a housing having a plurality of side apertures and a first set of needle cannula each having a passageway and a distal tip portion, each of the needle cannula while in its unconstrained configuration having a least one preformed bend proximate to said distal tip and being constrainable to the second configuration, the side openings are positioned along the wall of the housing and are spaced apart radially and axially, the distal tip portions of the first set of needle cannula being longitudinally aligned and radially spaced;   releasing the external constraining forces so the needle cannula radiates outwardly from the region of the outer cannula spaced proximally from a distal tip of the housing and the needle extends through a respective side aperture in the housing so said distal tip portion of each of said needle cannula substantially returns to the unconstrained configuration extending forwardly and radially outwardly from a respective preformed bend; and   delivering fluid through the passageways of the needle cannulas so the fluid exits through the opening in the needle and infuses into the tissue to ablate the tissue to provide lateral fluid infusion.   
     
     
         23 . The method of  claim 22 , further comprising a second set of needle cannula spaced proximally of the first set of needle cannula and having passageways for fluid infusion and extending through additional side apertures in the housing for lateral infusion of fluid when deployed from the constrained configuration to the unconstrained configuration, the second set of needle cannula each having a distal tip portion, and the distal tip portions of the second set of needle cannula being longitudinally aligned and radially spaced. 
     
     
         24 . The method of  claim 22 , further comprising a plurality of needle cannula extending out the distal opening of the housing. 
     
     
         25 . An apparatus for infusing fluid into a tumor comprising:
 a housing having a plurality of side apertures and a first set of needle cannula each having a passageway and a distal tip portion, each of the needle cannula while in its unconstrained configuration having a least one preformed bend proximate to said distal tip and being constrainable to the second configuration, the side openings are positioned along the wall of the housing and are spaced apart radially and axially, the distal tip portions of the first set of needle cannula being longitudinally aligned and radially spaced, the needle cannula having an constrained and unconstrained position, and in the unconstrained position, the needle cannula radiating outwardly from the region of the outer cannula spaced proximally from a distal tip of the housing and the needle extends through a respective side aperture in the housing so said distal tip portion of each of said needle cannula substantially returns to the unconstrained configuration extending forwardly and radially outwardly from a respective preformed bend, the needle cannulas having passageways for delivering fluid therethrough so the fluid exits through the opening in the needle and infuses into the tissue to ablate the tissue to provide lateral fluid infusion.   
     
     
         26 . The apparatus of  claim 26 , further comprising a second set of needle cannula spaced proximally of the first set of needle cannula and having passageways for fluid infusion and extending through additional side apertures in the housing for lateral infusion of fluid when deployed from the constrained configuration to the unconstrained configuration, the second set of needle cannula each having a distal tip portion, and the distal tip portions of the second set of needle cannula being longitudinally aligned and radially spaced. 
     
     
         27 . The method of  claim 26 , further comprising a plurality of needle cannula extending out the distal opening of the housing. 
     
     
         28 . The apparatus of  claim 25 , wherein the needle is composed of superelastic alloy. 
     
     
         29 . The apparatus of  claim 25 , wherein the handle is coaxial.