Relation of weights of intraaneurysmal thrombi to maximal right-to-left diameters of abdominal aortic aneurysms.

We determined the weight of operatively excised thrombi within abdominal aortic aneurysms (AAAs) in 42 patients aged 52 to 92 years (mean 73 +/- 9). The thrombi in the 32 men ranged in weight from 12 to 586 g (mean 162 +/- 135) and in the 10 women, from 12 to 351 g (mean 94 +/- 102). The maximal right-to-left diameter of the AAA by computed tomography immediately preoperatively in the 32 men ranged from 5.0 to 11.0 cm (mean 7.6 +/- 1.7), and in the 10 women from 4.0 to 10.5 cm (mean 6.7 +/- 1.9). The relation of the weight of the intraaneurysmal thrombus to the maximal right-to-left diameter of the AAA preoperatively was highly significant in both men (r = 0.72, p <0.001) and women (r = 0.88, p <0.001). In conclusion, the intraaneurysmal thrombi consisted virtually entirely of fibrin, indicating no evidence of organization.