Postoperative regression of retroperitoneal fibrosis in patients with inflammatory abdominal aortic aneurysms: evaluation with spiral computed tomography.

Partial or total regression of aortic and retroperitonel fibrosis after surgery has been reported in combination with inflammatory abdominal aortic aneurysm (AAA). In this report, we consider the most recent 21 patients with inflammatory AAA consecutively operated on at our institution. The group was composed of 19 men and 2 women, with a mean age of 66 years. In addition to preoperative CT angiographic study, abdominal ultrasound and aortoiliac angiography were also performed. There were no perioperative deaths. The perioperative morbidity rate was 9.5%. In 20 cases (95.2%), the aortic wall was subjected to histological examination with calculation of an inflammatory index. Each patient was reexamined with spiral CT angiography after surgery; postoperative results were assessed in terms of changes in maximal fibrotic-mantle thickness observed on follow-up spiral CT angiograms, expressed both in millimeters and percentage of change. Regression was analyzed for possible correlation with preoperative severity of fibrotic reaction, time of the postoperative exam, inflammatory index, and changes in the fibrotic process involving the adjacent structures. The results show that postoperative improvement was significantly more marked in cases characterized by higher preoperative inflammatory indices in the aneurysmal wall; the time course of regression was highly variable; but on the whole, improvement was more substantial during the early months after surgery, with significant slowing after the second or third year.