Flexible implantable devices or stents can navigate tortuous vessels of the neurovasculature. The devices can also conform to the shape of tortuous vessels of the vasculature. In some embodiments, the devices can direct blood flow within a vessel away from an aneurysm or limit blood flow to the aneurysm. Methods and structures are provided for adjusting, along a length of the device, the porosity of the device while maintaining a cross-sectional dimension. In some embodiments, small hooks releasably engage the stent at a proximal end and are able to resheath the stent by retracting a proximal retaining member where the hooks are coupled to. The hooks straighten, unfurl, or otherwise disengage the stent when either unrestrained by a catheter or when coming into contact with an external stimulus found in the patient's vasculature.