Aortic stents covering the renal arteries ostia: An animal study

PURPOSE: To evaluate the consequences of placing an aortic stent over the renal arteries. MATERIALS AND METHODS: The renal ostia of 11 pigs were covered by Strecker stents placed in the aorta, At 1 month, the degree of renal ostial stenosis was determined by means of angiography and gross pathologic and histologic examination, Any reduction in area of the renal ostia was considered significant, Preprocedure and 1-month serum creatinine levels were also examined. RESULTS: One stent migrated and was excluded from the study, There was one angiographic failure and, among the remaining 18 renal arteries evaluated, one was occluded, six were stenosed, and 11 were patent, Of the 10 samples available for pathologic examination, one was excluded from study because one stent was not fully deployed, A neointima was covering the struts crossing or encircling the renal arteries ostia with a mean area coverage of 43% +/- 30% (range, 0-84%), Serum creatinine levels rose from 71.1 mu moI/L +/- 7.1 preoperatively to 94.2 mu mol/L +/- 6.7 postoperatively (P < .01). CONCLUSION: An aortic stent placed over the renal arteries in pigs may compromise renal perfusion in the long-term because neointima tends to fill the spaces between the struts.