Capsule enteroscopy versus scintigraphy for the diagnosis of obscure gastrointestinal bleeding

Abstract

Background: capsule enteroscopy (CE) and Tc-99m red blood cell (RBC) scintigraphy are frequently used in the investigation of obscure gastrointestinal bleeding (OGIB). There are few data comparing both diagnostic modalities.This study aimed to assess the performance of CE and scintigraphy for the diagnosis of OGIB. Methods: patients who underwent CE and scintigraphy for OGIB were selected and analyzed retrospectively.The hemorrhagic potential of CE findings was rated using Saurin's classification. The concordance between both diagnostic techniques for bleeding detection and localization was analyzed. Results: eighty-five patients (62 % female), with a median age of 63 years, were included in the study. Capsule enteroscopy identified 37 patients (43 %) with high hemorrhagic potential (P2) lesions. Most scintigraphy exams were positive for gastrointestinal bleeding (82 %). No concordance was found in the detection of lesions with hemorrhagic potential between CE and scintigraphy (kappa < 0). The distribution of P0, P1 and P2 findings was similar in patients with positive or negative scintigraphy (p = 0.526). There was no agreement regarding the location of P2 findings in CE and the bleeding detected by scintigraphy (kappa < 0). Patients with P2 lesions had significantly lower median levels of hemoglobin (p = 0.002) at presentation. No significant differences were found in hemoglobin values between patients with positive and negative scintigraphy (p = 0.058). Conclusion: significant diagnostic discrepancy was observed between CE and scintigraphy. The findings of CE correlated better with hemoglobin values at presentation than scintigraphy results. Therefore, scintigraphy does not appear to be useful in the diagnostic workup of OGIB.