A medical device may include a shaft extending from a proximal end toward a distal end, the shaft including a lumen extending from the proximal end toward the distal end; a first stapling head at the distal end, the first stapling head configured to contain one or more staples, and the first stapling head having a block disposed within, and movable relative to, the first stapling head; a second stapling head at the distal end; and a pushing element extending through the lumen, the pushing element being movable from a first position to a second position, wherein transition of the pushing element from the first position to the second position urges the block to move toward second stapling head to deploy the one or more staples.