Minimally invasive methods and apparatus

Abstract

Methods and apparatus are provided to facilitate the minimally invasive removal of tissue biopsies and to facilitate the direct approach to anesthetizing the chest wall, in accordance with embodiments of the present invention. A pull-type cutting device 1 comprises two coaxially nested tubes, each extending from a proximal end 21 to a distal end 22 . The first tube 61 defines a guide wire lumen 23 for slidingly receiving a guide wire. The second tube 63 extends over the first tube 60 and coupled thereto at the distal end 22 defining an expandable portion 13 adjacent the distal end 22 . The second tube 63 defines an inflation lumen 25 extending from the shaft proximal end 21 to the expandable portion 13 . The inflation lumen 25 communicates inflation fluid from the proximal end 21 to the expandable portion 13 so as to inflate and deploy the expandable portion 13 . Disposed adjacent the shaft distal end 22 is a cutting head 10 comprising the expandable portion 13 having a cutting portion 11 distal from the shaft distal end 22.

What is claimed is: 
     
         1 . A biopsy device for use in extracting target tissue, comprising:
 a first needle defining a first-needle bore, a distal end of said first needle being effective to pierce tissue upon advancement in a patient;   a snare comprising a snare shaft and a deployable snare head at a distal end of said snare shaft, said snare shaft at least partially received within and extending through said first-needle bore, said snare head being made of a shape-memory material such that while retained within said first-needle bore the snare head is compressed to a first, low-profile configuration, and that on advancement relative to said first needle the snare head is deployed to second, high-profile configuration upon advancing beyond said first-needle distal end; and   a sheath insertable into said patient while accommodating said snare shaft through a bore of said sheath for guiding insertion thereof until a distal end said sheath reaches a location adjacent said snare head, said sheath being configured to dilate a tissue tract along said snare shaft between said snare head and a space outside said patient to a sufficient diameter to accommodate withdrawal of a target tissue that has been engaged by said snare head in said high-profile configuration.   
     
     
         2 . The biopsy device of  claim 1 , said sheath distal end being sharpened to core out said target tissue or a portion of tissue surrounding said target tissue for extraction thereof. 
     
     
         3 . The biopsy device of  claim 1 , further comprising a plurality of dilating needles having successively increasing diameters between a diameter of said first needle and a diameter of said sheath, wherein successive ones of said dilating needles are insertable into and removable from said patient while accommodating said snare shaft in respective bores thereof in order to dilate the tissue tract originally created by said first needle to a larger diameter approximately that of said sheath. 
     
     
         4 . A method of extracting target tissue, comprising:
 a) inserting a first needle into a patient toward a target tissue along a tissue tract between an entry point of the patient and said target tissue, said first needle having a first-needle bore and accommodating a snare therein, said snare having a snare shaft extending at least partially within said first-needle bore and a snare head disposed adjacent a distal end of said snare shaft, said snare head having a first, low-profile configuration within said needle bore;   b) advancing said first needle such that a distal end thereof passes beyond said target tissue, thereby disposing the target tissue between said first-needle distal end and an operator of said first needle;   c) advancing said snare relative to said needle at least until said snare head emerges from the first-needle distal end, whereupon said snare head is deployed into a second, high-profile configuration;   d) withdrawing said snare proximally until the high-profile snare head engages said target tissue;   e) withdrawing said first needle from said patient leaving behind said snare such that a proximal portion of said snare shaft extends out of said patient from said entry point;   f) inserting a sheath into said patient via said entry point along said tissue tract, wherein said snare shaft is accommodated through a bore of said sheath for guiding insertion thereof until a distal end said sheath reaches a location adjacent said snare head, thereby dilating or maintaining dilation of said tissue tract based on a diameter of said sheath so that said tract is large enough to accommodate withdrawal of the target tissue engaged by said snare head; and   g) withdrawing said snare from said patient, thereby also withdrawing said target tissue along said tract.   
     
     
         5 . The method of  claim 4 , said sheath distal end being sharpened, the method further comprising advancing said sheath until it cores out said target tissue or a portion of tissue surrounding said target tissue, thereby separating it from surrounding tissue. 
     
     
         6 . The method of  claim 4 , further comprising:
 after withdrawal of said first needle but before insertion of said sheath, successively inserting and then withdrawing into and from said patient, via said entry point and along said tissue tract, a plurality of respective dilating needles having successively increasing diameters between a diameter of said first needle and the diameter of said sheath, wherein said snare shaft is accommodated through respective bores of successive ones of the dilating needles for guiding insertion thereof along said tract, in order to dilate the tissue tract to a larger diameter approaching that of said sheath.   
     
     
         7 . The method of  claim 4 , further comprising locking a distal end of said sheath into said snare head thereby enclosing said target tissue within, and withdrawing said sheath and said snare together from said patient, whereby said target tissue is shielded from an environment outside said patient upon removal from said patient. 
     
     
         8 . The method of  claim 8 , further comprising cauterizing tissue surrounding said tissue tract as said sheath is withdrawn therefrom. 
     
     
         9 . The method of  claim 8 , further comprising delivering a tissue sealant material to said tissue tract as said sheath is withdrawn therefrom. 
     
     
         10 . The method of  claim 4 , wherein insertion of said first needle toward and past said target tissue is performed under image guidance. 
     
     
         11 . The method of  claim 4 , further comprising cauterizing tissue adjacent a tip of said first needle upon insertion thereof, thereby cauterizing the tissue tract as it is initially formed. 
     
     
         12 . The method of  claim 4 , said snare head being made of a shape-memory material and being compressed to said first, low-profile configuration within said first-needle bore. 
     
     
         13 . The method of  claim 4 , further comprising delivering a fluid to said tissue tract and heating said fluid to a temperature effective to seal tissue surrounding said tract. 
     
     
         14 . The method of  claim 13 , wherein said fluid is heated via delivery of RF energy thereto. 
     
     
         15 . The method of  claim 13 , wherein said fluid is heated via delivery of laser energy thereto.