Fate of the proximal aortic cuff: implications for endovascular aneurysm repair

Long-term success of endoluminally placed grafts for exclusion of abdominal aortic aneurysms (AAAs) relies on secure fixation at the proximal and distal cuffs and, as such, assumes that the fixation sites will not dilate over time. Data regarding this issue, however, are not yet available. This study was performed to evaluate the region of the proximal anastomosis in patients many years after having undergone conventional AAA repair to determine the potential for late dilatation after placement of an endoluminal device.

Three hundred forty-six patients underwent repair of an infrarenal AAA at our institution between January 1985 and December 1990. Of 97 eligible living patients, 33 both had their original CT scans available and underwent repeat scanning at a mean of 88.6 +/- 23.8 months (mean +/- SD; range, 40 to 134 months) after repair.

The overall 5-year survival rate was 73%. The mean preoperative infrarenal aortic cuff diameter by CT scan was 24.5 +/- 3.7 mm (range, 19 to 33 mm). At an average of 89 months after repair, the mean infrarenal aortic diameter increased 4.3 mm to 28.8 +/- 7.7 mm (range, 20 to 52 mm; p = 0.0004 by t test). The proximal cuff at this time measured 30 mm or more in 11 patients (33%), and as early as 6 years after operation three of the seven patients (43%) scanned within this time period had cuffs that were dilated to 30 mm or more. Late dilatation to 30 mm or more was rare (16%) in patients who had preoperative cuffs that measured 27 mm or less. The mean late iliac artery size was 16.9 +/- 8.9 mm (range, 10 to 52 mm), and 30% (10 of 33) measured 20 mm or more.

One third of all patients who survive AAA repair experience significant dilatation of their proximal aortic cuff over time. Proximal dilatation is rare but not absent in patients who have smaller initial aortic cuff diameters. This dilatation rarely causes problems after conventional suture fixation, but the long-term implications of cuff dilatation after endoluminal repair are unclear. Our findings suggest that endovascular aortic prostheses that have the ability to continue to self-expand many years after implantation may be required and that endovascular prostheses may not be the best option for patients who have a long life expectancy or for those who have preoperative proximal cuffs greater than 27 mm.