Active cannulas

Abstract

An active cannula which does more than merely maintain a passage is usable to create and/or enlarge a passage, to position a scope or instrument, to move or locate tissue, etc. The cannula can vary in size or shape as needed, intraoperatively. Because a cannula of the present invention is expandable, the surgeon can make a relatively small incision, stretch the tissue with the expandable cannula, contract the cannula and remove it, allowing the skin to come back to its unstretched condition. Thus, a smaller incision can be made to fit the same size instrument. The cannulas can assume such a non-circular shape, to fit into a natural skin opening and cause less trauma. The devices can be used to seal off a space, expand an existing space or a potential space for working or visualization, move tissue (for example, to stretch an incision), or protect tissue.

1 - 11 . (canceled)  
   
   
       12 : A surgical device comprising: 
 an elongate support member; and    an expandable member supported on the elongate support member, the expandable member including opposed rigid plates, a first flexible portion, and a second flexible portion, wherein introduction of an inflation medium increases a distance separating the rigid plates and causes radial expansion of the first and second flexible portions.    
   
   
       13 : The surgical device of  claim 12 , wherein the first flexible portion and portions of the rigid plates define a first plane when the expandable member is in an unexpanded condition.  
   
   
       14 : The surgical device of  claim 12 , wherein each of the rigid plates is substantially L-shaped.  
   
   
       15 : The surgical device of  claim 14 , wherein the rigid plates are diametrically opposed from one another.  
   
   
       16 : The surgical device of  claim 13 , wherein the second flexible portion is generally arcuate.  
   
   
       17 : The surgical device of  claim 12 , wherein the elongate support member includes a lumen extending therethrough.  
   
   
       18 : The surgical device of  claim 12 , wherein the rigid plates at least partially define a shape of the expandable member in an expanded condition.