Nishibe T, et al. - Researchers examined the value of simple renal cyst (SRC) as a risk factor for failure of sac shrinkage after endovascular aneurysm repair (EVAR). From October 2013 to May 2017, they assessed 155 patients with an infrarenal abdominal aortic aneurysm (AAA) or a common iliac artery aneurysm who underwent EVAR with the GORE C3 Excluder (W. L. Gore & Associates, Flagstaff, Ariz) at Tokyo Medical University Hospital. Of these, 92 patients had SRC (59.0%) and 63 patients had no SRC (41.0%). Outcomes revealed SRC presence as a risk factor for failure of sac shrinkage after EVAR. This indicates a more degenerated wall in AAA in patients with SRC vs those without SRC. They suggest a possible association of the property of the aneurysm wall with sac shrinkage after EVAR.