Prevented from being maintained? (4)
I believe the answer is:
kept
I believe this clue is a double definition.
'prevented' is the first definition.
(keeping is a kind of preventing)
'being maintained?' is the second definition.
(I've seen this in another clue)
'from' acts as a link.
(Other definitions for kept that I've seen before include "Saved" , "Retained possession" , "Maintained, detained" , "Retained, held back" , "Looked after" .)