A delicate tissue retraction system having a retractor, an introducer and a clamp mechanism. The retractor has a hollow retractor passage extending along a longitudinal axis from a proximal retractor end to a distal retractor end. The introducer has an introducer channel extending from a proximal introducer end to a distal introducer end. The introducer is configured to be removably installed within the retractor such that the proximal introducer end and distal introducer end are located along the longitudinal axis and the distal introducer end extends beyond the distal retractor end. The clamp mechanism is located on the introducer and includes a clamp axially aligned with the introducer channel, and control member configured to move the clamp between an open position and a closed position. The clamp may be used to hold a navigation probe inside the introducer, and a registration indicator may confirm the proper installation of the probe.
