An occlusion device delivery system can deliver an expandable coiled implant using a catheter. A distal portion of the catheter has proximal and distal apertures extending through a wall of the catheter. The expandable coiled implant is wound about the distal portion and has a proximal section that extends within the proximal aperture and a distal section that can extend radially within the distal aperture. Further, the system has an elongate member that extends through the lumen and engages and radially restrains the at least one of the proximal and distal sections within its respective aperture while engaged with the member.