Suture anchors for securing therapy delivery elements, such as stimulation leads or catheters, within a living body. The suture anchor includes an inner sleeve constructed with an inner layer of a softer, more pliable material that easily conforms to the therapy delivery element to reduce slippage and an outer layer constructed from a harder, stiffer durometer material that protects the therapy delivery elements from damage due to over-tightening the tie down sutures. A suture material located in the suture groove is tensioned to apply a radial compressive force. The reinforcing structure spreads the radial compressive force along a greater surface area of the therapy delivery element.