Isolated Right Colon Ischemia (IRCI) May Be the Heralding Presentation of Acute Superior Mesenteric Artery (SMA) Occlusion

Abstract

Purpose: In a previous study, we showed that IRCI had a poor outcome, requiring surgery or resulting in death, six and three times respectively more often than when ischemia involved other segments of the colon; 46.3% of patients with IRCI required surgery and 22.2% died. The SMA supplies blood to both the small intestine and the right colon and it is possible that the poor prognosis of IRCI may be explained by coincident acute SMA occlusion with resultant ischemic injury of the small intestine; the purpose of this study was to evaluate this possibility. Methods: This study is a retrospective chart review of all cases of colon ischemia identified at Montefiore Medical Center between the years 1998 through 2005 in whom splanchnic angiography was performed. Anatomic location of the ischemia, radiologic imaging, colonoscopic or surgical biopsy results, and patient outcomes were studied. Results: 21 patients were identified with colon ischemia confirmed by biopsy or radiologic imaging; 7 with IRCI and 14 with non-IRCI. 5 of the 7 patients with IRCI and 4 of the 14 patients with non-IRCI had unfavorable outcomes. Of the 5 patients with IRCI and unfavorable outcomes, 3 had acute SMA occlusion. None of the 4 patients with non-IRCI that had unfavorable outcomes had an SMA occlusion. Conclusions: Despite the small number of patients in this study, there is a suggestion that IRCI may be the presentation of otherwise silent SMA occlusive disease. Of 21 splanchnic angiograms performed in patients with colon ischemia, occlusive disease of the SMA was seen in 4 patients, all of whom had IRCI. Of these 4 patients with IRCI, 3 required surgery (1 of these died postoperatively). IRCI is a disease with high mortality that may be the heralding presentation of acute SMA occlusion (4 of 7 patients with IRCI had acute SMA occlusion). Vascular imaging is an important initial test in managing patients with IRCI.