A lead assembly for an electrical stimulation system includes terminals disposed along a proximal end of a lead body and electrodes disposed along a distal end of the lead body. The at least one fin element includes an outer surface portion that is configured and disposed to be in direct contact with a first fluid and an inner surface portion that is configured and disposed to be in direct contact with a second fluid. Flexural assemblies may be implemented to minimize lateral cross-coupling between the linear actuators.