Traction trocar apparatus and method

Abstract

The trocar system includes a cannula insertable through a body wall using an obturator having a distal tip. A traction tread disposed interiorly of the obturator inverts at the distal tip and extends proximally along the outer surface of the obturator or cannula. At the distal tip the tread can facilitate parting rather than cutting the tissue Along the outer surface, the tread can engage the tissue to pull it proximally along the advancing obturator. This produces counter forces which can result in a net proximal force facilitating distention of the abdominal wall and separation of the abdominal wall from internal organs The traction tread can be axially and/or radially continuous. An associated method of operation includes the steps of contacting the body wall with the traction tread at the distal tip, and engaging the body wall with the traction tread along wall portions facing the outer surface

1 - 5 . (canceled)  
   
   
       6 . A surgical instrument, comprising: 
 a shaft having a tubular configuration with an outer surface, an axial channel, and a distal tip;    at least one flexible traction tread carried within the axial channel of the tubular shaft and extending outwardly of the shaft at the distal tip; and    a handle coupled to the at least one traction tread exteriorly of the shaft, the handle being moveable proximally to withdraw the at least one traction tread distally through the distal tip.    
   
   
       7 . The surgical instrument recited in  claim 6 , the at least one traction tread including at least two traction treads, the at least two traction treads being substantially equally spaced around the circumference of the shaft.  
   
   
       8 . The surgical instrument recited in  claim 7 , wherein the at least two traction treads are diametrically positioned on the shaft.  
   
   
       9 . The surgical instrument recited in  claim 6 , wherein the at least one traction tread is radially continuous and comprises a woven, mesh sheath having a tubular configuration.  
   
   
       10 . The surgical instrument recited in  claim 6 , wherein the at least one traction tread is axially continuous and comprises a mesh belt.  
   
   
       11 - 29 . (canceled)