Both: (a) percutaneous placement of sacral nerve lead or leads using fluoroscopic guidance, or open placement of sacral nerve lead or leads; and (b) intra‑operative test stimulation, to manage: (i) detrusor over‑activity that has been refractory to at least 12 months conservative non‑surgical treatment; or (ii) non‑obstructive urinary retention that has been refractory to at least 12 months conservative non‑surgical treatment (H) (Anaes.)