An aneurysm -LRB- or aneurism -RRB- -LRB- -RRB- is a localized , blood-filled dilation -LRB- balloon-like bulge -RRB- of a blood vessel caused by disease or weakening of the vessel wall .

An aneurysm -LRB- or aneurism -RRB- is a blood-filled bulge of a blood vessel .
