A single port entry surgical instrument has an elongated structure with lumens through which surgical tools and an image capturing device may be inserted and controllably extended out of its distal end for performing a medical procedure, a tubular-shaped balloon disposed around the elongated structure, and an expandable retractor disposed around the balloon so that when the balloon is inflated, the retractor expands and locks in an expanded configuration to retract extraneous tissue. The port entry may be secured using the expandable retractor or sealed using another inflatable balloon disposed around the proximal end of the elongated structure and centered in the port entry.