Systems and methods for implanting a surgical sling in a patient by a transobturator approach are disclosed. A sling delivery device couplable to a sling assembly with the surgical sling includes a guide tube and an extendible shaft section movable inside the guide tube. At least a portion of the shaft may be made of a shape memory material and can, when extended, assume a shape different from the shape of the guide tube in which the shaft is housed. This allows the extended shaft to navigate along a path that tracks close to bone structures, in particular the ischiopubic ramus, and prevents damage to surrounding tissue.