Suprarenal fixation of endovascular aortic stent grafts: assessment of medium-term to long-term renal function by analysis of juxtarenal stent morphology.

OBJECTIVE The effect of suprarenal stent fixation during endovascular aortic aneurysm repair (EVAR) on renal function remains unclear. A unique validated three-dimensional intraluminal imaging technique was used to analyze the effect of suprarenal stent position relative to renal artery orifices. Also analyzed was its medium-term to long-term effects on renal function. METHODS The study cohort comprised 29 of 34 consecutive patients who underwent EVAR with the Zenith endograft system from September 1999 to March 2002 at a single institution. The precise locations of the uncovered suprarenal stent struts were assessed by a virtual endoscopic imaging technique. Anatomic and quantitative categorization of patients was made according to the configuration of uncovered stent struts across the renal artery ostia (RAO). The anatomic subgroups were defined as struts located centrally or peripherally across both RAO. The quantitative subgroups were defined as RAO crossed by multiple struts, a solitary strut, or no struts. The subgroups were compared for their renal function, as assessed by temporal measurements of serum creatinine concentration and creatinine clearance, and renal parenchymal perfusion defects, as assessed using contrast-enhanced computed tomography (CT). RESULTS Mean follow-up was 52.7 months. Separate subgroup analysis for both anatomic and quantitative configurations did not demonstrate any significant difference in renal function between the different strut permutations (P > .05). Follow-up imaging confirmed one case of renal infarction secondary to an occluded accessory renal artery, although this patient had normal serum creatinine levels. CONCLUSION RAO coverage by suprarenal uncovered stents does not appear to have a significant effect on renal function as evaluated by creatinine measurements in patients with normal preoperative renal function.