Bowstring Phenomenon in Renal Artery Aneurysm Exclusion Using a Viabahn Stent Graft

A 77-year-old man presented with an incidental finding of right renal artery aneurysm without symptoms. Computed tomography revealed a 22 mm saccular aneurysm with a wide neck at the main renal artery trunk. An 8 × 100 mm Viabahn stent graft (W. L. Gore, Flagstaff, AZ) was deployed by fully pulling back the guiding sheath. However, the deployment knob was not able to be pulled. We returned the guiding sheath to the original position and confirmed the cause was the bowstring phenomenon. Because avoidance of this phenomenon required straightening of the tortuous vessel, the stent graft was deployed by short pull-back of the guiding sheath. Computed tomography after a year revealed no opacification of the aneurysm and the patency of the stent graft.