Inflammatory abdominal aortic aneurysm: A postoperative course of retroperitoneal fibrosis.

PURPOSE: The long-term outcome and the development of retroperitoneal fibrosis after surgery on an inflammatory aortic aneurysm was studied.

METHODS: Between 1989 and 1997, 1035 patients underwent surgery for an abdominal aneurysm, 42 of whom (4.1%) had typical signs of inflammation. All patients underwent computed tomography (CT) scans before operation, and 26 patients were followed up with a CT scan after a median of 36 months (range, 10 to 91 months).

RESULTS: The inflammatory layer resolved completely in only 23% of the patients. One patient had marked progression, 35% of patients showed improvement, and the remaining patients had no change, compared with the preoperative findings. Although clinical symptoms subsided in 90% of patients, in five cases an involvement of the ureter or intestine that did not exist at the time of operation developed. Although ureteral involvement to the inflammation tends to subside after surgery, persisting fibrosis was associated with ureteral entrapment in 30% of these cases and resulted in renal compromise in 49%. Hydronephrosis that was not present at the time of operation was found in 19% of patients, despite improving or stable inflammatory lesions.

CONCLUSION: This case-control study supports the findings that retroperitoneal fibrosis persists longer than previously thought, and progression might even occur. Formerly uninvolved organs might become included in the process despite regression of the layer, leading to considerable problems if the condition is not treated in institutions familiar with this complex disease. We advocate a moderated follow-up scheme, as in the case of ordinary abdominal aortic aneurysm, and the need for long-term surveillance of inflammatory aneurysms.