A Prospective Study of Changes in Morphology and Dimensions of Abdominal Aortic Aneurysms following Endoluminal Repair: A Preliminary Report

Purpose: The aim of this prospective study was to analyze early changes in morphology and dimensions of abdominal aortic aneurysms (AAA) following endoluminal repair. Methods: Forty-two of 62 patients undergoing endoluminal repair of AAAs between May 1992 and November 1994 were potentially available for follow-up at 6 months or longer after operation. After excluding patients with failed endoluminal repairs, patients who died within 6 months of operation, and patients with anastomotic aneurysms, a study group of 30 patients remained. Contrast-enhanced computed tomography (CE-CT) was performed preoperatively, within 10 days of operation, and at 6 and 12 months postprocedure. Based on the postoperative CE-CT findings, patients were divided into two groups: those with no extravasation of contrast into the aneurysmal sac (group I; n = 26), and those in which there was contrast extravasation (“leak”) into the aneurysmal sac (group II; n = 4). Results: The mean maximum diameters of AAAs in group I diminished progressively at 6 and 12 months, while those in group II increased. Twenty-three (88%) patients in group I had decreased diameter of AAA, while all patients in group II had progressive increase in AAA diameter. Patients who had an increase in AAA diameter had a significantly higher incidence of leak compared with those who had a decrease in diameter (p = 0.001). Conclusions: The majority of AAAs in which the sac has been excluded from the general circulation diminish in size following successful endoluminal repair. An increase in size occurs in those AAAs in which a communication exists between the aortic lumen and the sac. These results suggest that successfully excluded AAAs that continue to increase in size should be suspected of having an undetected leak.