True abdominal aortic aneurysm in Marfan syndrome

True abdominal aortic aneurysm (AAA) in patients with Marfan syndrome is relatively rare because most aortic aneurysms in this disease are dissecting aneurysms in the thoracic area. Therefore, its clinical characteristics and long-term outcome are still unclear.

We examined six patients (3 men, 3 women) with Marfan syndrome who had a true AAA. These patients underwent surgical treatment from 1972 to 2004, and we investigated the clinical and histologic findings.

The patients were a median age of 45 years (range, 23-73 years) at the time of operation. The median maximum AAA diameter was 76 mm (range, 30-140 mm). Two AAAs ruptured, one of which had twice undergone stent graft insertion before open repair. There was one anastomotic aneurysm and three aortic dissections with additional repair. Marfan-related cardiac complications, all found perioperatively or postoperatively, comprised three patients with annuloaortic ectasia and four with aortic regurgitation. Three patients died, including one death during the operation. Only slight mural thrombus was seen at nonruptured AAAs, and each surgical specimen of aneurysmal wall demonstrated significant cystic medial necrosis in the tunica media.

True AAAs in Marfan syndrome seemed to have several specific features, such as the tendency to occur in relatively young patients, lack of mural thrombus, and susceptibility to dissection and rupture, and the patients have poor life expectancy. Therefore, careful follow-up, keeping these features in mind, is important to treat Marfan syndrome patients with a true AAA.