A stent assembly (10) is formed with a plurality of stent rings (12) which have sections (16, 18, 24) which are of a non-biodegradable material and struts and tie bars (20, 14) which are at least partially biodegradable. The stent ring (12) thus partially biodegrades in a patient over time. The structure is such that the apices (16, 18, 24) of the stent ring (12) are of a non-biodegradable material and thus able to behave as a conventional non-biodegradable stent, that is with the same flexibility and expansion force consistent with such stent rings. Parts (34, 44) of the stent ring (12) will degrade in time, thereby reducing the restoring force produced by the stent ring (12) and reducing the amount of foreign material retained within a patient's body. In one embodiment, the stent ring (12) will separate into individual components after a period.