Devices, systems, and methods employ at least one ferromagnetic structure sized and configured for placement in a tissue region. A component is attached to the structure to stabilize its placement in the tissue region. An anchoring structure holds the component in a state of tension. The anchoring structure can, e.g., take the from of an anchoring body that expands in situ. The anchoring structure can be adjustable for adjusting the state of tension. The component can be elastic, to deflect under load in a prescribed manner and to recover an initial shape when unloaded.