Nerve surveillance cannulae systems

Abstract

An expandable tip cannula system, comprising: a hollow cannula shaft having a proximal end and a distal end; and an expandable tip mounted at the distal end of the hollow cannula shaft, the expandable tip comprising a plurality of generally-triangular shaped petals held together in a radially-inwardly tapered arrangement between adjacent petals, each petal comprising a nerve sensing electrode disposed therein.

1 . A system for accessing a surgical target site, comprising: 
 a plurality of tissue displacement members dimensioned to be advanced to a surgical site and moved relative to one another to provide surgical access to said surgical target site; and    an expandable member coupled to said plurality of tissue displacement members to prevent tissue from migrating into said surgical target site during surgical access.    
   
   
       2 . The system of  claim 1 , wherein said plurality of tissue displacement members may be at least one of straight and curved in shape.  
   
   
       3 . The system of  claim 1 , wherein said expandable member is coupled to an exterior surface of said plurality of tissue displacement members.  
   
   
       4 . The system of  claim 1 , wherein said expandable member is disposed over at least half of the length of said tissue displacement members.  
   
   
       5 . The system of  claim 1 , wherein said expandable member is disposed over at least seventy-five percent of the length of said tissue displacement members.  
   
   
       6 . The system of  claim 1 , wherein said tissue includes neural tissue.  
   
   
       7 . An apparatus for preventing tissue ingress during surgical access, comprising: 
 an expandable member dimensioned to be coupled to a surgical access system to prevent tissue from migrating into a surgical target site during surgical access.    
   
   
       8 . The apparatus of  claim 7 , wherein said surgical access system includes a plurality of tissue displacement members dimensioned to be advanced to said surgical target site and moved relative to one another to provide surgical access to said surgical target site.  
   
   
       9 . The apparatus of  claim 8 , wherein said plurality of tissue displacement members may be at least one of straight and curved in shape.  
   
   
       10 . The apparatus of  claim 7 , wherein said expandable member is coupled to an exterior surface of said surgical access system.  
   
   
       11 . The apparatus of  claim 8 , wherein said expandable member is disposed over at least half of the length of said tissue displacement members.  
   
   
       12 . The apparatus of  claim 8 , wherein said expandable member is disposed over at least seventy-five percent of the length of said tissue displacement members.  
   
   
       13 . The apparatus of  claim 7 , wherein said tissue includes neural tissue.  
   
   
       14 . A method for accessing a surgical site, comprising the steps of: 
 (a) coupling an expandable member to a plurality of tissue displacement members;    (b) advancing the plurality of tissue displacement members to a surgical target site; and    (c) moving said plurality of displacement members relative to one another to provide surgical access to said surgical site, wherein said expandable member prevents tissue from migrating into said surgical target site.    
   
   
       15 . The method of  claim 14 , wherein said plurality of tissue displacement members may be at least one of straight and curved in shape.  
   
   
       16 . The method of  claim 14 , wherein said expandable member is coupled to an exterior surface of said tissue displacement members.  
   
   
       17 . The method of  claim 14 , wherein said expandable member is disposed over at least half of the length of said tissue displacement members.  
   
   
       18 . The method of  claim 14 , wherein said expandable member is disposed over at least seventy-five percent of the length of said tissue displacement members.  
   
   
       19 . The method of  claim 14 , wherein said tissue includes neural tissue.