Purpose: Colon ischemia (CI) is thought to be caused by localized occurrences of non-occlusive vascular disease. Cases of stroke and congestive heart failure have been found to be associated with a high erythrocyte red cell distribution width (RDW), the altered red cell morphology possibly increasing blood viscosity and decreasing blood flow in the microcirculation. The purpose of this study was to see whether a similar association could be made with CI.
Methods: We performed a retrospective review of the charts of 256 patients with biopsy-proven CI, evaluated their RDW's and compared them with the RDW's of 256 healthy patients referred for colonoscopy for indications other than anemia or bleeding. Patients were excluded from analysis if they had a known malignancy, advanced liver disease, chronic kidney disease requiring hemodialysis or if they had received a blood transfusion within 3 months prior to colonoscopy. The complete blood count closest to the day of colonoscopy was evaluated for each patient. An RDW of 14.2% or higher was considered elevated for this study. Data were compared using a chi squared analysis.
Results: Patients with CI had a higher mean age (70.2 yrs) compared with the control group (58.9 yrs); both groups were relatively matched for gender (CI: 69.0% female; control: 64.8% female). An elevated RDW was observed in 105 patients (41.0%) with CI and 86 patients (33.6%) within the control group (p=0.083).
Conclusion: Red cell distribution width, a reflection of the variability in circulating red blood cell size, when elevated, does not appear to confer an increased risk for colon ischemia.