Aortic aneurysm size and graft behavior after endovascular stent-grafting:Clinical experiences and observations over 3 years

Purpose: To assess the long-term safety and efficacy of aortic endografts i n terms of clinical outcome, continuing aneurysm exclusion, and changes of aneurysm size and graft configuration. Methods: Between August 1994 and July 1997, 190 patients (176 men; mean age 68.7 years, range 40-87) with aortic and aortoiliac aneurysms were treated with endovascular stent-grafts (Stentor, Vanguard, and EGS) in a tertiary care municipal hospital setting. Follow-up involved clinic visits every 3 t o 6 months with contrast-enhanced computed tomography (CT), color duplex, a nd plain abdominal radiographs at regular intervals; angiography was used s electively. All data were collected prospectively and entered into a comput erized database. Results: implantation was possible in 188 (98.9%) patients. Early conversio n to open surgical repair was required in 14 (7.4%) patients. Primary endol eaks were detected in 32 (16.8%) patients. Perioperative mortality was 0.53 % (1/190). During follow-up, 17 (8.9%) additional patients were converted t o open repair over a mean 20.9 months. Thirty-seven secondary procedures to treat endoleaks and pelvic outflow occlusions were performed in 30 (15.8%) patients. Changes in stent configuration suggestive of endograft disintegr ation were observed in 31 (29.8%) of 104 abdominal radiographs. intralumina l layering of thrombus was seen on contrast-enhanced CT images in 20 patien ts. A significant trend (chi(2)(4) = 12.34, p < 0.025) toward aneurysm enla rgement was seen in patients with persistent endoleaks at a mean 18-month f ollow-up. Conclusions: Although endoleaks after aortic stent-graft placement tend to cause ongoing aneurysm growth, we have also observed aneurysm shrinkage des pite ongoing endoleak. The presence or absence of an endoleak in itself may be a poor predictor of successful stent-graft therapy. Lifelong surveillan ce is needed to assure successful aneurysm exclusion and stability or shrin kage of the aneurysm sac. Technical improvements in stent materials and des ign are necessary to guarantee long-term stability and safety of the device .