Endovascular grafting for abdominal aortic aneurysms: Changing incidence and indications for conversion to open operation

The incidence and indications for conversion from endoluminal to open repair of abdominal aortic aneurysms are changing. This paper is based on a 5-year experience in which endoluminal repair of abdominal aortic aneurysms was undertaken in 156 patients. Primary conversion at the original operation was required in 14 patients and secondary conversion at a subsequent operation was required in 9 patients. The reasons for primary conversion were access problems (n = 2), balloon related problems (n = 2), endograft migration (n = 4), endograft thrombosis (n = 1) and failed deployment of a bifurcated endograft (n = 5). Twelve of 14 primary conversions occurred in the first half of the study period, in which 59 endoluminal abdominal aortic aneurysms repairs were undertaken. Improvements in technology and interventional techniques for overcoming obstacles, as well as increasing experience, has resulted in primary conversion being limited to two patients in the most recent 2.5-year period in which 97 endoluminal repairs were undertaken. The reasons for secondary conversion were renal arteries covered by the endograft (n = 2), increasing abdominal aortic aneurysm diameter in the absence of endoleak (n = 1) and persistent endoleak (n = 6). The latter group comprised three patients with intact aneurysms and three with known endoleaks who presented with ruptured aneurysms. The current indications for primary conversion include: (i) rupture of the aorta; (ii) complete migration of the endograft resulting in obstruction of the iliac arteries; and (iii) irreversible twisting of a non-modular bifurcated endograft. The current indications for secondary conversion include: (i) persistent endoleak; (ii) sealed endoleak with continued abdominal aortic aneurysms expansion; (iii) apparently successful endoluminal repair without evidence of endoleak but continued abdominal aortic aneurysms expansion; and (iv) infected endograft.