A medical device comprises an elongate sheath defining a first lumen and comprising a distal portion and a flexible proximal portion. The medical device further comprises an elongate instrument slidably disposed at least partially within the first lumen. The elongate instrument comprises a flexible tubular proximal section and a rigid distal section defining a second lumen. The medical device further comprises an instrument handle coupled to a proximal end of the elongate instrument. The medical device further comprises a sheath handle coupled to a proximal end of the elongate sheath. The sheath handle is configured to at least partially receive the instrument handle. The medical device further comprises a holding mechanism coupled to the sheath handle. The holding mechanism is rotatable to engage the elongate instrument to maintain the rigid distal section of the elongate instrument in an extended position from the distal portion of the elongate sheath.