Factors affecting the regression of surgically replaced abdominal aortic aneurysms.

PURPOSE

After endovascular therapy for abdominal aortic aneurysms, aneurysm sac shrinkage is considered to be the best marker of successful treatment. Such shrinkage, however, is infrequent and the rate of shrinkage is variable because of endoleaks. To investigate the factors that influence such contraction, the aneurysm sac regression after a conventional surgical replacement of the abdominal aortic aneurysm in an inclusion fashion was studied.

METHODS

Abdominal aortic aneurysms that measured 5 cm in diameter or larger were studied in 35 patients who underwent surgical replacement. The aneurysm sac was closed anterior to the prosthesis. Of the 35 cases, 4 aneurysms were inflammatory and 10 had aneurysm wall circumferential calcification of greater than 40%. Computed tomography was performed preoperatively, and at 1 week, and then 3 months postoperatively.

RESULTS

The maximum major and minor diameters of the aneurysmal sac decreased significantly from 1 week to 3 months after surgery (major diameter: 49 +/- 12 to 32 +/- 8 mm and minor diameter: 39 +/- 10 to 26 +/- 7 mm). In inflammatory aneurysms, the maximum major and minor diameters were significantly larger at 3 months postoperatively, in comparison to nonspecific aneurysms. Among the 31 patients with nonspecific aneurysms, the maximum major diameter was significantly larger in those with aneurysmal calcification of greater than 40% of its circumference at 3 months postoperatively, in comparison to noncalcified aneurysms.

CONCLUSIONS

The surgically repaired abdominal aortic aneurysm contraction tends to develop over 3 months, and inflammation, thickening, and calcification of the aneurysm wall are all considered to influence the regression of the aneurysm.