The immediate inflammatory response following aortic reconstruction with two types of sealed Dacron grafts was studied in a prospective, randomized manner. C-reactive protein (CRP) levels were measured before surgery and on days 2 and 8 postoperatively. In the collagen-sealed group (n = 10) CRP levels were 10 +/- 9.6, 180.2 +/- 48.3, and 54.3 +/- 34.3 mg/L, respectively. In the gelatin-impregnated group (n = 10) the values were 10.5 +/- 8.7, 200.7 +/- 27.3, and 80.3 +/- 30.2 mg/L, respectively. The slight differences were not significant according to the analysis of variance test for repeated measurements. These findings suggest that implantation of a knitted Dacron graft sealed with collagen does not lead to a higher inflammatory reaction compared with a gelatin-sealed graft.