Medical device and treatment method

Abstract

Medical devices and methods for puncturing tissue in a patient. The devices include a needle with a rigid proximal shaft, a flexible distal shaft, and a distal tip. The distal tip includes an electrode for delivering energy to puncture a tissue. In some embodiments, the distal shaft includes a superelastic material. In other embodiments, the distal shaft includes both a superelastic material and a non-superelastic material. The distal shaft includes shape memory enabling formation of an anchor within the patient.

What is claimed is: 
     
         1 . A needle device comprising:
 an elongate member having a distal shaft and a proximal shaft, the distal shaft including superelastic material;   a distal end of the distal shaft having an electrode for delivering energy to puncture a tissue; and   a distal curved section of the distal shaft capable of forming an anchor that is operable to retain the distal end of the elongate member at a location within a patient's body.   
     
     
         2 . The device of  claim 1 , wherein the anchor is formed in a partial spiral shape. 
     
     
         3 . The device of  claim 1 , wherein the anchor is formed in a pigtail shape having a curve within a curve. 
     
     
         4 . The device of  claim 1 , wherein the distal curved section includes shape memory enabling movement between a straightened configuration and a curved configuration. 
     
     
         5 . The device of  claim 4 , wherein the straightened configuration occurs upon forces being applied to the distal curved section. 
     
     
         6 . The device of  claim 4 , wherein the curved configuration occurs in an absence of forces being applied to the distal curved section. 
     
     
         7 . The device of  claim 1 , wherein the distal shaft and the proximal shaft are joined at a junction, the junction being a superelastic hinge which overlaps with, and is joined to, both the proximal shaft and the distal shaft. 
     
     
         8 . The device of  claim 1 , wherein the proximal shaft overlaps the distal shaft such that the distal shaft is partially nested within the proximal shaft. 
     
     
         9 . The device of  claim 1 , wherein the electrode is mechanically coupled to the distal shaft. 
     
     
         10 . The device of  claim 1 , wherein the electrode is integral with the distal shaft. 
     
     
         11 . The device of  claim 1 , wherein the distal shaft includes an imaging marker. 
     
     
         12 . The device of  claim 1 , wherein the proximal shaft includes columnar strength sufficiently rigid to enable advancement of the elongate member through a puncture in the tissue. 
     
     
         13 . The device of  claim 12 , wherein the distal shaft includes an inner layer and an outer layer. 
     
     
         14 . The device of  claim 13 , wherein one of the inner layer and the outer layer is formed by a non-superelastic material. 
     
     
         15 . The device of  claim 13 , wherein at least one of the inner layer and the outer layer is a superelastic layer forming from 10 to 90 percent of a thickness of the distal shaft. 
     
     
         16 . The device of  claim 13 , wherein a thickness of the non-superelastic material is varied to adjust rigidity of the distal shaft. 
     
     
         17 . A needle comprising a distal shaft and a proximal shaft joined at a junction, the needle having a distal tip which includes an electrode for delivering energy to puncture a tissue, wherein a distal portion of the distal shaft has a partial spiral shape when not being manipulated that is operable to anchor a distal end of the needle in a location in a patient's body, wherein the distal shaft is comprised of a superelastic material, and wherein the proximal shaft is comprised of a non-superelastic material for providing columnar strength for pushability to enable advancement of the needle through a puncture in the tissue. 
     
     
         18 . A method for puncturing tissue of a patient, the method comprising:
 introducing a sheath into a vascular system of the patient;   introducing a dilator into the sheath and advancing to position the dilator against a tissue;   introducing a needle device into the proximal region of the dilator, the needle device including an elongate member having a distal shaft and a proximal shaft, the distal shaft including superelastic material, a distal end of the distal shaft having an electrode for delivering energy to puncture the tissue, and a distal curved section;   advancing the needle device through the dilator to the tissue wherein the distal shaft is sufficiently flexible to conform to a shape of the dilator; and   delivering energy from an energy source through the electrode of the needle whereby the energy creates a puncture.   
     
     
         19 . The method of  claim 18  further including advancing the needle device through the dilator to expose the distal curved section of the distal shaft and thereby forming an anchor that is operable to retain the distal end of the elongate member at a location within the patient.