Patent ID: 7414038

Claim:
In a method for embolizing an arteriovenous aneurysm in a patient, the improvement comprising administering to said patient an ester derivative of a polysaccharide, wherein the polysaccharide is selected from the group consisting of pullulan and elsinan as an embolizing material, said ester derivative (i) having a weight-average molecular weight of 10,000 to 500,000 daltons, (ii) having a ratio of the weight-average molecular weight to the number average molecular weight of below two, (iii) having an average substitution degree of acyl group of greater than 2.5 (iv) being preparable into a solution with a viscosity of below 1,000 centipoises (cps) at 20° C. when dissolved in dimethyl sulfoxide; (v) being substantially insoluble in blood, and (vi) having a solubility in dimethyl sulfoxide of at least 10 mg/ml at 20° C.