Apparatus and methods are provided for closing a tubular structure within a patient's body. The apparatus includes a needle including a proximal end including a hub, a distal end including a sharpened distal tip, a lumen having an oblong cross-section extending proximally from the distal end, and defining a longitudinal axis between the proximal and distal ends, and a clip deliverable from the lumen. The clip is compressible between a relaxed state in which a plurality of tines of the clip are shaped to engage and close a tubular structure within a patient's body, and a stressed state in which the tines are compressed to allow the clip to be loaded into the. The apparatus may also include a pusher member for deploying the clip from the distal tip of the needle such that the tines engage and close a tubular structure through which the tubular member is directed.