Diagnostic Yield of Capsule Endoscopy in Overt GI Bleeding Compared to Iron Deficiency Anemia

Abstract

Purpose: Capsule endoscopy (CE) is an established technique for the identification of small bowel lesions in patients with obscure GI bleeding. It is also performed in the setting of iron deficiency anemia (IDA) when standard upper and lower endoscopy fail to reveal a source of blood loss. Studies have been conflicting regarding whether the diagnostic yield differs in those with obscure overt GI bleeding and those with IDA with or without occult bleeding. The aim of the study was to compare the diagnostic yield of CE in these two groups. We also sought to identify clinical factors associated with positive CE findings. Methods: A retrospective chart review was performed for all patients who had undergone CE for evaluation of overt GI bleeding or IDA at our center from May 2005 until March 2011. Only lesions felt to represent a definite or probable source of bleeding according to previously established guidelines were included in the diagnostic yield calculation. Variables in the two groups were compared using Chi-Square and two-sample T-test. Results: A total of 631 CE procedures done for obscure overt gastrointestinal bleeding (n=220) and IDA (n=411) were studied. Diagnostic yield was 56.4% in overt bleeding patients and 50.6% in IDA patients (p=0.168). Table 1 shows the identified lesions in the two groups. Patients with overt bleeding were more likely to have fresh blood (13.2% vs. 6.8%, p=0.008) and altered blood (3.6% vs. 0.5%, p=0.004) compared to IDA patients. 58.2% of patients with positive CE findings had prior transfusion requirement while 42.2% of patients with negative CE findings had transfusion requirement (p<0.001). Patients with positive CE findings were found to have lower hemoglobin (8.3 ± 2.2 vs. 9.0 ± 2.2 g/dL, p<0.001) and were older (66.2 ± 12.2 vs. 64.0 ± 13.6, p=0.034) compared to patients with negative CE findings.Table 1: . No Caption available.Conclusion: Diagnostic yield of CE in patients with obscure overt GI bleeding and patients with iron deficiency anemia was not significantly different making CE an important tool in the work-up of unexplained iron deficiency anemia. Patients with positive CE findings were more likely to have prior transfusion requirement, lower hemoglobin, and older age when compared to patients with negative CE findings.