A cannula has a longitudinal base member having a first clamping end and a longitudinal arm member pivotally attached to the longitudinal base member and having a second clamping end, the cannula being in a closed position when the first and second clamping ends are brought together. A first clamp member is located at the first clamping end and has a first passage. A second clamp member is rotatably attached to the arm member at the second clamping end and has a second passage. The first and second passages form a combined passage when the clamp is in the closed position. The cannula may have a first locking member positioned on the arm member and a second locking member positioned on the base member. The first and second locking members interact with each other to lock the cannula in the closed position.