Transrenal bare stents in endovascular treatment of abdominal aortic aneurysms.

Endovascular stent-graft (EVSG) repair of abdominal aortic aneurysms (AAA) has continued to evolve since its introduction in 1991. The ability to secure a stent-graft in the suprarenal aorta with an uncovered proximal stent is felt by many to improve the overall fixation of the device and decrease the risk of migration and endoleak. While preliminary evidence suggests that type I endoleaks may be less frequent when transrenal bare stents are used, this has yet to be conclusively shown. Of obvious concern is the risk of renal parenchymal damage or diminished blood flow following placement of a bare stent across the renal artery ostia. Numerous small series have shown little or no risk of significant renal impairment at intermediate length of follow-up after transrenal stent placement. The presence of a stent across the renal artery orifice does not appear to interfere with later interventions on that artery, such as angioplasty and stenting.