Patent ID: 8486045

Claim:
A method for accessing an anatomic structure, the method comprising: a) providing a cannula adapted for insertion through the wall of an anatomic structure, the cannula comprising a housing; a distal tube having a wall with a thickness defined by medial and lateral surfaces; at least one opening in the distal tube medial surface; a helical impression on the distal tube medial surface; a proximal tube located adjacent the cannula housing, the proximal tube having a raised helical lateral surface adapted to engage the helical impression on the distal tube; an obturator having a lock adapted to engage the opening; a collapsible anchor disposed about the distal tube in communication with the obturator; b) moving the obturator distally relative to the cannula housing to collapse the anchor about the cannula; c) inserting the cannula into an anatomic structure; d) moving the obturator proximally relative to the cannula housing to deploy the anchor; and e) rotating the obturator relative to the cannula housing to cause the distal tube helical impression to rotatingly engage the proximal tube's raised helical surface driving the distal tube in a proximal or distal direction.