Relevance of capsule endoscopy in patients with obscure gastrointestinal bleeding - a comprehensive real-world study.

Gastrointestinal bleeding is a common clinical problem. In 5% of these cases, no source of bleeding can be found by gastroscopy or colonoscopy. The aim of this study was to investigate which of these patients benefit from capsule endoscopy (CE) and how it affects subsequent management. 305 patients who underwent CE for suspected obscure gastrointestinal bleeding at two German gastroenterological centers were analysed retrospectively. All patients had previously undergone gastroscopy and colonoscopy without evidence of a sufficient source of bleeding. The PillCam SB (Medtronic) was used for CE. A source of bleeding was identified in 63.9% (195/305) of cases with CE. A source of bleeding tented to be detected more frequently by CE in patients with melena only (72.4%, p=0.002) compared to patients with hematochezia with or without melena (55.6% and 45.9%). Furthermore, early CE (day 1: 73.3%, day 2: 61.5%, day 3: 53.8%; p=0.378) and complete CE (71.1% vs. 38.8%, p=2.56*10-6) were associated with a higher detection rate. Blood was detected in 31.5% (96/305) of all CEs. However, this tended to be observed more often in patients with a high need for red blood concentrates (0 RBC: 21.4%, 1-2 RBC: 34.9%, 3-4 RBC: 38.3%, ≥5 RBC: 45.7%; p=0.026), a derailed INR (<1.15: 32.6%, 1.16-2.0: 19.5%, 2.0-3.0: 32.0%, >3: 60.0%; p=0.023) and early CE (day 1: 46.7% (7/15), day 2: 41.0% (16/39), day 3: 25.0% (13/52); p=0.244). In 12.5% of the patients a double-ballon enteroscopy (DBE) was conducted. The detection of blood during CE increased the probability for a DBE (25.0% vs. 6.7%; OR: 4.61; p=2.061*10-5). Detection of a source of hemorrhage with CE increased the likelihood of detecting a source of hemorrhage with DBE (48.1% vs. 9.1%; OR: 8.83; p=0.030). Performing a DBE did not affect the length of hospitalisation (without DBE 10d, with DBE 9.1d, p=0.81) or the number of RBCs transfused after CE (without DBE 1.9 RBC, with DBE 2.4 RBC, p=0.67). In particular, patients with melena and an increased need for RBCs could benefit from an early and complete capsule endoscopy. If a source of bleeding was detected by CE, the probability of a finding in DBE could be increased.