In at least one embodiment, a medical device can comprise an elongate outer sheath that extends along a sheath longitudinal axis and defines a central lumen extending therethrough, the elongate outer sheath can comprise a proximal sheath portion and a distal sheath portion. A first guidewire can comprise a first guidewire end and a second guidewire end, the first guidewire can extend from the first and second guidewire ends through the central lumen and can form a distal looped portion. An occlusion device can be disposed at a distal end of an elongate flexible shaft. The elongate flexible shaft can extend from the proximal sheath portion through the central lumen. The occlusion device can include a guide lumen through which the first guide wire passes.