Creative works describing old atomic vessel (5)
I believe the answer is:
aorta
'vessel' is the definition.
(blood vessel)
'creative works describing old atomic' is the wordplay.
'creative works' becomes 'art' (I've seen this before).
'describing' is an insertion indicator (describe can mean to form the outline of).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'atomic' becomes 'a' (eg in A-test, atomic test).
'art' placed around 'o' is 'aort'.
'aort'+'a'='AORTA'
(Other definitions for aorta that I've seen before include "it's drawing blood!" , "Heart's great artery" , "Main route from the heart" , "Trunk artery from the heart" , "Tube" .)