Endoleak after stent-graft treatment of abdominal aortic aneurysm: a meta-analysis of clinical studies

Background: Endoleak is the major complication after endovascular treatment of abdominal aortic aneurysm (AAA) and its incidence seems to remain signi ficant. Little is known about the association of device type and configurat ion with respect to the incidence, location, time of onset and fate of endo leakage. Methods: A meta-analysis was performed via a Medline search of clinical stu dies after 1995 dealing with the endovascular treatment of AAA. Details of number of patients treated, configuration and type of endovascular device w ere collected. Data concerning site of origin, time of occurrence and fate of the endoleak were retrieved, along with information on change in diamete r of the aneurysm with time. Results: The 23 publications included reported on 1189 patients. The 1118 p atients with successfully inserted transfemoral endovascular grafts experie nced 270 endoleaks (24 per cent). The majority arose from the distal stent attachment site (36 per cent), were present immediately after stent-graft p lacement (66 per cent) and were persistent in time (37 per cent). Tube graf ts were more frequently affected by endoleakage (35 per cent; P < 0.0001), especially at the distal stent attachment site (51 per cent), than bifurcat ed grafts (18 per cent; P = 0.004) and aortounilateral devices (20 per cent ; P = 0.70). Self-expandable stent-grafts were more frequently associated w ith endoleaks (25 per cent) than balloon-expandable stent-grafts (17 per ce nt) (P = 0.037). Conclusion: Endovascular treatment of AAA is an evolving held. Even after t he initial learning curve and attention to device-related problems, it is s till accompanied by a significant number of endoleaks. Uniform presentation of results of treatment is necessary for analysing the effect of differenc es between patients, aneurysm morphology and device type.