Obscure gastrointestinal bleeding: diagnostic performance of multidetector CT enterography

The American Society for Gastrointestinal Endoscopy (ASGE) diagnostic algorithm for obscure gastrointestinal bleeding: eight burning questions from everyday clinical practice

The diagnosis and management of patients with obscure gastrointestinal bleeding are often long and challenging processes. Over the last 10 years the introduction in clinical practice of new diagnostic and therapeutic procedures (i.e. Capsule Endoscopy, Computed Tomographic Enterography, Magnetic Resonance Enterography, and Device Assisted Enteroscopy) has revolutionized the diagnostic/therapeutic work-up of these patients. Based on evidence published in the last 10 years, international scientific societies have proposed new practice guidelines for the management of obscure gastrointestinal bleeding, which include these techniques. However, although these algorithms (the most recent ones are endorsed by the American Society for Gastrointestinal Endoscopy - ASGE) allow the management of the large majority of patients, some issues still remain unsolved. The present paper reports the results of the discussion, based on the literature published up to September 2011, among a panel of experts and gastroenterologists, working with Capsule Endoscopy and with Device Assisted Enteroscopy, attending the 6th annual meeting of the Italian Club for Capsule Endoscopy and Enteroscopy. Eight unresolved issues were selected: each of them is presented as a "Burning question" and the "Answer" is the strategy proposed to manage it, according to both the available evidence and the discussion among participants.

CT enterography in obscure gastrointestinal bleeding: a systematic review and meta-analysis

The objective of this article is to provide a comprehensive and update overview of clinical application of CT enterography (CTE) in the evaluation of obscure gastrointestinal bleeding (OGIB). We performed a systematic review of relevant literatures in PubMed, EMBASE and The Cochrane Library and pooled the yield of CTE and the incremental yield (IY) of CTE over an alternate modality. A total of 18 studies (n = 660) reported the yield of CTE in evaluating OGIB and the pooled yield was 40% (95% confidence interval (CI): 33-49%). Seven studies (n = 279) compared the yield of CTE with capsule endoscopy (CE). The yield for CTE and CE for all findings was 34% and 53%, respectively (IY = -19%, 95% CI = -34% to -4%). When considering the types of identified lesions, the yield was significantly different for vascular and inflammatory lesions but not significantly different for neoplastic or other lesions. Two studies (n = 63) compared the yield of CTE with double-balloon enteroscopy (DBE). The yield for CTE and DBE was 38% and 78%, respectively (IY = -40%, 95% CI = -55% to -25%). Three studies (n = 49) compared the yield of CTE with digital subtraction angiography. The yield for CTE and digital subtraction angiography was 64% and 60%, respectively (IY = 4%, 95% CI = -40% to 47%). CTE is an excellent diagnostic tool in patients with OGIB. It may play a complementary role to CE and can be used as a triage tool prior to DBE in evaluating OGIB.

Small bowel diagnostics: current place of small bowel endoscopy

The small intestine has been difficult to examine by traditional endoscopic and radiologic techniques. Until the end of the last century, the small bowel follow through was the primary diagnostic tool for suspected small bowel disease. In recent years capsule endoscopy, deep enteroscopy using balloon-assisted or spiral techniques, computerized tomography and magnetic resonance enteroclysis or enterography have facilitated the diagnosis, monitoring, and management of patients with small bowel diseases. These technologies are complementary, each with its advantages and limitations. In the present article, we will discuss the different options and indications for modern diagnostic methods for visualization of the small bowel. We also try to provide a clinical rationale for the use of these different diagnostic options in less established, newly emerging, indications for small bowel evaluation.

Obscure and occult gastrointestinal bleeding: comparison of different imaging modalities

Patients with persistent, recurrent, or intermittent bleeding from the gastrointestinal (GI) tract for which no definite cause has been identified by initial esophagogastroduodenoscopy, colonoscopy, or conventional radiologic evaluation are considered to have an obscure GI bleeding (OGIB). The diagnosis and management of patients with OGIB is challenging, often requiring extensive and expensive workups. The main objective is the identification of the etiology and site of bleeding, which should be as rapidly accomplished as possible, in order to establish the most appropriate therapy. The introduction of capsule endoscopy and double balloon enteroscopy and the recent improvements in CT and MRI techniques have revolutionized the approach to patients with OGIB, allowing the visualization of the entire GI tract, particularly the small bowel, until now considered as the "dark continent" . In this article we review and compare the radiologic and endoscopic examinations currently used in occult and OGIB, focusing on diagnostic patterns, pitfalls, strengths, weaknesses, and value in patients' management.

Diagnostic yield of dual-phase computed tomography enterography in patients with obscure gastrointestinal bleeding and a non-diagnostic capsule endoscopy

BACKGROUND AND AIM

In patients with obscure gastrointestinal (GI) bleeding, capsule endoscopy is widely used to determine the source of bleeding. However, there is currently no consensus on how to further evaluate patients with obscure GI bleeding with a non-diagnostic capsule endoscopy examination. This study aims to determine the diagnostic yield of dual-phase computed tomographic enterography (CTE) in patients with obscure GI bleeding and a non-diagnostic capsule endoscopy.

METHODS

Patients with obscure GI bleeding who were referred for capsule endoscopy were prospectively enrolled. Obscure GI bleeding was defined as overt if there was obvious GI bleeding; otherwise it was defined as occult. Patients with a non-diagnostic capsule endoscopy and no contraindications underwent a CTE.

RESULTS

Capsule endoscopy was performed in 52 patients; 26 patients (50%) had occult GI bleeding and 26 patients (50%) had overt GI bleeding. CTE was then performed in 25 of the 48 patients without a definitive source of bleeding seen on capsule endoscopy. The diagnostic yield of CTE was 0% (0/11) in patients with occult bleeding versus 50% (7/14) in patients with overt bleeding (P < 0.01). Using clinical follow up as the gold standard, for the 25 patients with a non-diagnostic capsule, CTE had a sensitivity of 33% (95% confidence interval 0.15, 0.56) and a specificity of 75% (95% confidence interval 0.22, 0.99).

CONCLUSIONS

In patients with a non-diagnostic capsule endoscopy examination, CTE is useful for detecting a source of GI bleeding in patients with overt, but not occult, obscure GI bleeding.

Obscure gastrointestinal bleeding: difficulties in comparing CT enterography and video capsule endoscopy

A paper reports the results of a retrospective study that was designed to evaluate the potential role of video capsule endoscopy (VCE) in elucidating the cause of bleeding in patients with obscure gastrointestinal bleeding (OGIB) for whom CT enterography was negative. The authors highlight the limitations of dual-phase CT enterography for the detection of flat lesions of the small bowel such as ulcers, angiodysplasias or arteriovenous malformations, and confirm the superiority of VCE for the detection of this category of lesions. This commentary discusses some of the issues raised.

KEY POINTS

• Video capsule endoscopy surpasses CT enterography in detecting flat small bowel lesions. • Retrospective VCE and CT enterography findings in obscure bleeding need further evaluation. • A fair and unbiased comparison of the two investigations is still needed.

CT enterography of Crohn's disease

CT enterography (CTE) is a technique using neutral oral contrast, intravenous contrast and thin cut, multiplanar CT acquisitions to optimize small bowel imaging. One of the primary indications for CTE is the detection and evaluation of Crohn's disease. This article summarizes the advantages/disadvantages, scanning technique, imaging findings, performance and pitfalls of CTE for the evaluation of Crohn's disease.