The application describes a catheter with controlled flexibility being relatively stiff at a proximal portion and more flexible at a distal portion, the flexibility profile providing sufficient levels of both pushability and flexibility. The catheter has a smaller cross-section than reinforced catheters, while still providing a variation in flexibility. The catheter includes an expandable implant having an outer surface, a handle coupled to the expandable implant, and a delivery sheath coupled to the handle. The delivery sheath has an outer surface, a lumen in which the expandable implant is disposed, the lumen defined by an inner surface of the delivery sheath, and a plurality of openings near a distal end of the delivery sheath. The plurality of openings extends from the inner surface to the outer surface of the delivery sheath, and the plurality of openings includes a first region of openings and a second region of openings, wherein the first region has a higher density of openings than the second region, and each of the openings in the first region are larger than each of the openings in the second region. A sleeve is disposed over the outer surface of the delivery sheath in the region containing the plurality of openings. The density and size of the openings allows for controlled flexibility of the catheter.
