A retractor member configured for insertion through a channel of an access member and for moving soft tissue at a treatment site accessible through the channel, comprising: a body having a proximal end and a distal end spaced from each other along a longitudinal direction, the distal end defining a retractor blade, the body defining a first surface and a second surface opposite each other along a transverse direction substantially perpendicular to the longitudinal direction, wherein the body has a first side and a second side spaced from each other along a lateral direction substantially perpendicular to the longitudinal and transverse directions; and an attachment device configured to selectively attach the body to a portion of the access member such that the body is extendable through the channel and is translatable relative to the access member along the longitudinal direction while the body is attached to the portion of the access member, wherein the attachment device extends from at least one of the first and second sides at a longitudinal portion of the body located intermediate the proximal and distal ends, such that the attachment device is configured to reside within the channel for securing the retractor member to an inner surface of the access member; characterized in that the attachment device comprises a pair of wings each extending circumferentially from the first and second sides, respectively, at the longitudinal portion, wherein the pair of wings are compliant and are configured to be flexed inward toward each other from a neutral configuration to a flexed configuration by the inner surface of the access member when the pair of wings are disposed in the channel, such that a return force of the pair of wings causes the pair of wings to engage the inner surface of the access member so as to attach the body to the portion of the access member. a body having a proximal end and a distal end spaced from each other along a longitudinal direction, the distal end defining a retractor blade, the body defining a first surface and a second surface opposite each other along a transverse direction substantially perpendicular to the longitudinal direction, wherein the body has a first side and a second side spaced from each other along a lateral direction substantially perpendicular to the longitudinal and transverse directions; and an attachment device configured to selectively attach the body to a portion of the access member such that the body is extendable through the channel and is translatable relative to the access member along the longitudinal direction while the body is attached to the portion of the access member, wherein the attachment device extends from at least one of the first and second sides at a longitudinal portion of the body located intermediate the proximal and distal ends, such that the attachment device is configured to reside within the channel for securing the retractor member to an inner surface of the access member; characterized in that the attachment device comprises a pair of wings each extending circumferentially from the first and second sides, respectively, at the longitudinal portion, wherein the pair of wings are compliant and are configured to be flexed inward toward each other from a neutral configuration to a flexed configuration by the inner surface of the access member when the pair of wings are disposed in the channel, such that a return force of the pair of wings causes the pair of wings to engage the inner surface of the access member so as to attach the body to the portion of the access member.