Described herein are introducer devices and methods for using an introducer device to facilitate passing an endoluminal instrument to a target region of a body cavity. An introducer device may include a tubular member having an inner wall that defines a channel configured to receive the endoluminal instrument and a plurality of projections disposed in the channel at perimetrically spaced apart locations around the inner wall, where the projections extend inward and are configured to offset the endoluminal instrument from the inner wall, thereby creating a space between the endoluminal instrument and the inner wall. A method for using an introducer device may include passing the endoluminal instrument to a first instrument insertion depth within the introducer device, advancing the introducer device in the body cavity, and advancing the endoluminal instrument to a second instrument insertion depth within the introducer device.