Management of a gradually enlarging post stenotic inferior mesenteric artery aneurysm with hostile aortoiliac anatomy

A 72-year-old male was referred for asymptomatic, incidentally detected atherosclerotic superior mesenteric artery (SMA) and celiac occlusion.Review of computed tomography (CT) imaging revealed a gradually enlarging 2-cm previously undiagnosed inferior mesenteric artery aneurysm (IMAA) (A).Comorbidities included hypertension, stroke, obstructive sleep apnea on continuous positive airway pressure, chronic renal failure (baseline creatinine, 2), spine surgery, left nephrectomy, solitary right kidney with multiple calcified small renal arteries, bladder cancer, peripheral arterial disease, and prior failed lower extremity bypass.On examination, the right femoral pulse was palpable with significant groin scarring; the left femoral pulse was not palpable.The inferior mesenteric artery (IMA) with the post stenotic aneurysm was the only patent mesenteric artery with robust collateralization to the occluded superior mesenteric artery (SMA) (B).Aortic anatomy was hostile, with only a 1.5-cm mid-aortic infrarenal clamp zone (B).Antegrade SMA/ celiac recanalization was unsuccessful.Open repair was performed, the IMAA was dissected, and the test clamp on the IMA after heparinization did not cause bowel ischemia.An aortic to IMA bypass was performed with 8-mm Dacron graft (C); histopathology confirmed an atherosclerotic aneurysm.His postoperative recovery was uneventful; he was dismissed home on postoperative day 5 in excellent functional status.Postoperative computed tomography angiography at 6 months demonstrates a widely patent IMA.(C).The patient provided consent for publication (D/Cover).In our patient, IMAA expansion was 1 cm over 7 years.There are only 13 reports of IMAA associated with celiomesenteric occlusion, and none report the growth rate. [1][2]][3][4][5][6][7][8][9][10][11][12][13][14] Although the largest reported IMAA size is 6 cm, fatal rupture is reported at 2 cm. 1 The Society for Vascular Surgery practice guidelines advise individualized management for IMAA due to rarity; there are no specific size guidelines for repair. 13This case demonstrates that, as expected, the natural history of a IMAA associated with IMA stenosis (post stenotic dilatation) as well as celiomesenteric occlusion is continued or more rapid growth due to the jet-phenomenon hemodynamics. 5We recommend repair for an IMAA with celiomesenteric occlusion to prevent rupture, or at a size of 1.5 cm if the SMA and celiac are patent.Aneurysm growth could be different in smokers or in patients with other aneurysms such as aortoiliac or peripheral aneurysms.Early endovascular intervention