Endoluminal introducer with contamination avoidance

A method for using an introducer device to facilitate passing a solid endoluminal instrument to a target region of a body cavity, the method comprising:

• passing the endoluminal instrument within a channel defined by an inner wall of a tubular member of the introducer device to a first instrument insertion depth, wherein the introducer device comprises an insufflation port coupled to the tubular member and configured to pass insufflation gas into the channel;
• advancing the introducer device toward the target region of the body cavity while the endoluminal instrument is positioned within the introducer device at the first instrument insertion depth;
• and
• advancing the endoluminal instrument within the introducer device to a second instrument insertion depth that is distal to the first instrument insertion depth, wherein when the endoluminal introducer is at the second instrument insertion depth there is a space between the endoluminal instrument and the inner wall of the introducer device, wherein the introducer device comprises a plurality of projections disposed in the channel at circumferentially spaced apart locations around the inner wall that extend inward and are configured to offset the endoluminal instrument from the inner wall, thereby creating the space between the endoluminal instrument and the inner wall.