Pararenal aortic aneurysms: definition, classification, directions for surgery

The formidable impact derived by the endovascular correction (Evar) of abdominal aorta aneurysms (AAA), has risen its classification aspects. The topographical criteria has assumed importance in decisional diagnostic-therapeutic strategy especially in cases of so called pararenal aneurysms (PRAA). PRAA defines aneurysm being involved underenal juxtarenal aorta (JRA), or more rarely, suprarenal aorta with normal aortic diameter at level of celiac (JRA), or more rarely, suprarenal aorta with normal aortic diameter at level of celiac trunk. The morphologic-topographic aspect is considered in function of selection or eligibility of patients to Evar or standard open surgery, in the need of a suprarenal clamping for the tailoring of proximal anastomosis or anchorage of endoprotesis. Various specific classifications for these aneurysms have been proposed (Schumacher, 1997; Wolf, 2000; Ayari, 2001) that considers: 1. Aneurysm collar: short/long/tortuous, 2. Relations with renal arteries, 3. Relations with the left renal vein. The choice between the technical solution to prefer either open or endovascular surgery will have to consider a series of additional variables to the standard direction common to every AAA based on dimensions and morphology. Priority will have to be given to evaluating, using shared morphologic-topographical classification criteria, real incidence of PRAA-JRA (3%-20% in literature review); greater post opening mortality (1.3%-15.3%); dimensions (AAA with diameter > or = 5.5 cm in operating risk assessment of single patient, in clinical evolution and increase in the time of the lesion); in common occurrence in AAA of steno-obstructive lesions of renal arteries and involvement of same ones in the aneurysm collar in need of reconstruction and suprarenal aortic clamping.