Expandable thoracic access port

1. A method of accessing an internal cavity of a patient comprising:

forming an opening in a patient's tissue;

providing an access assembly including:

an outer member positionable outside the patient and defining an opening therein dimensioned to receive a surgical instrument, the outer member including first and second portions, the first and second portions being relatively movable to adjust a dimension of the opening;

an inner member configured and dimensioned for insertion through the opening in the patient's tissue;

a flexible member extending between the inner member and the outer member and operatively associated with the outer member, the flexible member defining a passageway configured and dimensioned to receive the surgical instrument, wherein relative movement between the first and second portions of the outer member adjusts tension on the flexible member; and

a first locking member including a first arm;

inserting the inner member into the opening in the patient's tissue such that the inner member is passed into an intercostal space defined between the patient's adjacent ribs such that the flexible member extends proximally through the opening in the patient's tissue;

enlarging the opening in the patient's tissue and the passageway through the flexible member by effecting relative movement between the first and second portions of the outer member; and

subsequently actuating the first locking member to lock the outer member in one of a plurality of select expanded positions by embedding a tip of the first arm in a soft material of the outer member.

2. The method according to claim 1 , further including passing the surgical instrument and/or a tissue specimen through the passageway extending through the flexible member and the opening in the patient's tissue.

3. The method of claim 1 , wherein inserting the inner member into the opening in the patient's tissue includes folding the inner member.

4. The method of claim 1 , wherein actuating the first locking member includes sliding a first collar in relation to the outer member to embed the tip of the first arm in the soft material of the outer member.

5. The method of claim 4 , wherein sliding the first collar in relation to the outer member includes contacting a ramped surface of the first arm with the first collar to cam the first arm towards the soft material of the outer member.

6. The method of claim 5 , wherein providing the access assembly includes providing a second locking member including a second arm.

7. The method of claim 6 further including actuating the second locking member to lock the outer member in one of the plurality of select expanded positions by embedding a tip of the second arm in the soft material of the outer member.

8. The method of claim 7 , wherein actuating the second locking member includes sliding a second collar in relation to the outer member to embed the tip of the second arm in the soft material of the outer member.

9. The method of claim 8 , wherein sliding the second collar in relation to the outer member includes contacting a ramped surface of the second arm with the second collar to cam the second arm towards the soft material of the outer member.

10. A method of accessing an internal workspace comprising:

inserting an access assembly into an opening in tissue such that an inner member of the access assembly is positioned beneath the tissue, an outer member of the access assembly is positioned above the tissue, and a flexible member connecting the inner and outer members extends through the opening in the tissue;

moving the outer member into an expanded configuration to enlarge the opening in the tissue by effecting relative movement between first and second portions of the outer member;

actuating a locking mechanism of the access assembly to lock the outer member in the expanded configuration by embedding a portion of the locking mechanism in a portion of the outer member; and

introducing at least one surgical instrument into the internal workspace through a passageway defined by the flexible member.

11. The method of claim 10 , wherein moving the outer member into the expanded configuration applies tension to the flexible member.

12. The method of claim 10 , wherein actuating the locking mechanism includes pivoting a first arm of the locking mechanism towards the outer member.

13. The method of claim 12 , wherein actuating the locking mechanism further includes embedding a tip of the first arm in a soft material of the outer member.

14. The method of claim 13 , wherein actuating the locking mechanism includes sliding a first collar in relation to the outer member such that the first collar contacts a ramped surface of the first arm to cam the first arm towards the soft material of the outer member.

15. The method of claim 14 , wherein actuating the locking mechanism further includes pivoting a second arm of the locking mechanism towards the outer member.

16. The method of claim 15 , wherein actuating the locking mechanism further includes embedding a tip of the second arm in the soft material of the outer member.

17. The method of claim 16 , wherein actuating the locking mechanism further includes sliding a second collar in relation to the outer member such that the second collar contacts a ramped surface of the second arm to cam the second arm towards the soft material of the outer member.