A method of inhibiting tissue migration comprises positioning an open area of a hood against or adjacent to a tissue region. The method also comprises displacing an opaque fluid with a transparent fluid from the open area. The method includes engaging a portion of the tissue region within the open area via an end effector advanced through the open area and which grasps onto the portion. The end effector includes a tapered section, tapered along its entire length, through which a lumen extends. The tapered section includes threads extending from a surface of the tapered section in a direction orthogonal to the longitudinal axis. The tissue region is pierced while displacing the opaque fluid with the transparent fluid through the distal opening of the hood and while maintaining engagement of the portion of the tissue region such that distal movement of the tissue is inhibited.