Overt colon ischemia after endovascular aneurysm repair: the importance of microembolization as an etiology.
OBJECTIVE
The purpose of this study was to analyze the incidence, severity, and etiologic factors of the development of colon ischemia after endovascular aortoiliac aneurysm repair (EVAR).


METHODS
During the last 9 years we performed 278 elective EVARs using a variety of grafts. To facilitate these repairs, one hypogastric artery (HA) was coil embolized in 109 patients and both HAs were coil embolized in 13 patients. The preprocedural status of the inferior mesenteric, hypogastric, and iliac arteries as well as anatomical characteristics of the abdominal aortic aneurysm were determined arteriographically and by computerized tomographic scans. Postoperative colon ischemia was documented by colonoscopy or operative findings.


RESULTS
Colon ischemia occurred in eight patients (2.9%). Three patients with colon ischemia died and had evidence of widespread (cutaneous, renal, small bowel, and/or lower extremity) microembolization. One of these three had a colectomy and microscopic emboli were present. One other patient who required a colectomy also had pathologic evidence of colonic microembolization but survived. Four other patients with colon ischemia were treated conservatively and survived. In one patient, previous colectomy with interruption of mesenteric collaterals may have been a contributory cause of colon ischemia. Of the eight patients with colon ischemia, only one had unilateral HA occlusion, and none had bilateral HA occlusion. The other 121 patients with unilateral and bilateral HA occlusion had no evidence of colon ischemia.


CONCLUSIONS
Colon ischemia occurs after EVAR with an incidence approximating that of open repair. Colon ischemia was unrelated to HA interruption. Embolization appears to be a major cause of colon ischemia, although inadequate mesenteric collateral circulation may also play an etiologic role. Mortality with colon ischemia accompanied by widespread embolization was high, whereas colon ischemia without it was often mild and amenable to nonoperative management.
Dadian
N
N
Division of Vascular Surgery Montefiore Medical Center - Albert Einstein College of Medicine, New York, New York, USA.
Ohki
T
T
Veith
F J
FJ
Edelman
M
M
Mehta
M
M
Lipsitz
E C
EC
Suggs
W D
WD
Wain
R A
RA
D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D017130:Angioplasty / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D003082:Colectomy; D003108:Colonic Diseases / Q000145:classification / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D003113:Colonoscopy; D004617:Embolism / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D004621:Embolization, Therapeutic / Q000009:adverse effects; D006801:Humans; D017543:Iliac Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D007083:Iliac Artery; D015994:Incidence; D007511:Ischemia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015607:Stents; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D011138:Polytetrafluoroethylene