The invention is directed to an apparatus for use in a transluminal procedure. The apparatus, comprising, for example, a housing having a guide lumen and a seal proximal to a distal end of the housing that extends across and completely seals the guide lumen; a fixation element in the housing and adapted to secure the distal end of the housing to tissue; and a channel extending through the side wall of the housing having an outlet in communication with the lumen distal of the seal. Methods are also provided. For example, a method includes, performing a transluminal procedure by: securing a datum and position indicator to a wall of a target lumen; forming an opening in the wall; advancing an instrument through the opening; and tracking the advancement of the instrument using the datum and position indicator.