This invention is directed to methods for treating aneurysms wherein the aneurysmal sac is filled with a non-particulate agent or plurality of such agents and/or with a fluid composition which solidifies in situ. Filling of the aneurysmal sac employs sufficient amount of the non-particulate agent or plurality of such agents and/or the fluid composition to inhibit blood flow into the aneurysm sac. In addition, the methods of this invention also provide for non-endogenous isolation of the parent artery proximal and distal to the aneurysmal sac from systemic blood flow of the treated mammal. The combination of these features provides for treatment of the aneurysmal sac while, at the same time, inhibiting aneurysm formation and/or regrowth in the diseased portions of the arterial wall proximal and distal to the treated aneurysm.