An apparatus includes a locking portion, a flexible pulling portion, a flexible body, and a plurality of barb features extending laterally from the body. The locking portion is configured to receive the pulling potion. The pulling portion is configured to engage and translate relative to the locking portion after the locking portion has received the pulling portion. The flexible body extends from the locking portion to the pulling portion. The flexible body is configured to form a loop when the pulling portion engages the locking portion. The loop is configured to decrease in size in response to pulling of the pulling portion relative to the locking portion. The barb features are configured to engage a tubular region of tissue and thereby form pleats in the tubular region of tissue.
