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: 
 a tubular member having an open proximal end and an open distal end, the open proximal end and the open distal end defining a bore through the tubular member;    an inner wall disposed in the bore and extending along a length of the tubular member;    a lumen defined between an outer wall of the tubular member and the inner wall;    an expandable member disposed in a distal region of the tubular member, wherein ends of the expandable member are affixed to the tubular member at spaced apart locations; and    at least one filament extending from the outer wall of the tubular member to the expandable member, the at least one filament limiting the expansion of the expandable member upon introduction of an inflation medium to the expandable member.    
   
   
       13 : The surgical device of  claim 12 , wherein a diameter of the unexpanded expandable member is substantially equal to a diameter of the tubular member.  
   
   
       14 : The surgical device of  claim 12 , wherein the expandable member has a generally pyramidal configuration and defines a plane at a distal end of the expandable member when the expandable member is in an expanded state.  
   
   
       15 : The surgical device of  claim 14 , wherein the plane of the expandable member is parallel to a plane defined by the open distal end of the tubular member and axially spaced therefrom.  
   
   
       16 : The surgical device of  claim 12 , wherein expansion of the expandable member moves surrounding tissue, thereby creating a working space distally of the surgical device.  
   
   
       17 : The surgical device of  claim 16 , wherein the working space is accessible from the open proximal end of the tubular member.  
   
   
       18 : An inflatable medical device comprising: 
 a support member having a longitudinal axis, a proximal portion, a central portion, and a distal portion; and    an inflatable balloon mounted on the support member and having an inner surface, an outer surface, a proximal end, a distal end, and an inflatable portion therebetween, the support member extending at least the entire length of the inflatable balloon when, fully inflated such that the inflatable portion expands between the proximal and distal portions of the support member, the inflatable balloon comprised of a thin layer of uniform material including a plurality of rigid members arranged along the inflatable portion to define a predetermined shape of the inflatable balloon when the inflatable balloon is fully inflated.    
   
   
       19 : The device of  claim 18 , wherein the support member includes a lumen.  
   
   
       20 : The device of  claim 19 , wherein the support member includes a number of tethering cords, the number of tethering cords corresponding to the number of rigid members, said tethering cords having proximal and distal ends, said proximal ends attached to the support member and said distal ends attached to the rigid members.  
   
   
       21 : The device of  claim 18 , wherein said rigid members are disposed circumferentially about the support member such that each rigid member partially overlaps at least one other rigid member when the balloon is in an uninflated state and each rigid member is separate from every other rigid member when the balloon is fully inflated.  
   
   
       22 : The device of  claim 21 , wherein said rigid members are disposed in a substantially planar arrangement.  
   
   
       23 : The device of  claim 22 , wherein said proximal portion has a larger diameter than said central portion.  
   
   
       24 : The device of  claim 22 , wherein said distal portion has a larger diameter than said central portion.  
   
   
       25 : The device of  claim 22 , wherein said central portion has a smaller diameter than said proximal and distal portions and, in an uninflated state, said balloon lies flat within a recess formed by said central portion.