The evolution of endoscopy: wireless capsule cameras for the diagnosis of occult gastrointestinal bleeding and inflammatory bowel disease

Detection and localization of active gastrointestinal bleeding with multidetector row computed tomography angiography: a 5-year prospective study in one medical center

GOAL

To prospectively assess the utility of multidetector row computed tomography angiography (MDCTA) in the diagnosis of active gastrointestinal bleeding (GIB).

BACKGROUND

MDCTA is a relatively recent advance in CT scanning technology enabling excellent vascular visualization and detection of various vascular abnormalities. However, there is no prospective study with a large population evaluating the role of MDCTA in the diagnosis of active GIB.

STUDY

From January 2006 to January 2011, 113 consecutive patients with clinical signs of active GIB underwent MDCTA (16-slice, 64-slice, or dual-source). The criteria for positive CT findings included active extravasation of contrast material within bowel lumen, abnormal bowel mucosal enhancement, vascular malformation, abnormally enhancing polyp or diverticulum, or tumor. Two radiologists reviewed the images and assessed CT findings in consensus. The standards of reference included digital subtraction angiography, endoscopy, surgery, or final pathology reports. Sensitivity, specificity, positive and negative predictive values, and accuracy of MDCTA for detection of active GIB were evaluated.

RESULTS

Positive CT findings for active GIB were identified in 80 of 113 patients (70.8%), all of which were confirmed by 1 or more reference standard. Negative MDCTA results were obtained in 33 patients (29.2%). Of these, 27 patients did not require any further intervention and were discharged without incident. The overall sensitivity, specificity, positive and negative predictive values, and accuracy of MDCTA was 86.0%, 100%, 100%, 60.6%, and 88.5%, respectively.

CONCLUSIONS

MDCTA is an accurate first-line screening method for detection and localization of GIB and can guide triage in patients with active GIB.

10 years of capsule endoscopy: an update

Capsule endoscopy (CE) has evolved in a few short years to become a first-line, noninvasive diagnostic technique for the small bowel. CE is now being utilized worldwide to assess patients for obscure gastrointestinal bleeding, possible Crohn's disease, celiac disease and small bowel tumors. The device is now used in tandem with balloon enteroscopy to direct therapeutic interventions. Alterations and improvements in CE have also led to the evaluation of both the esophagus and colon. It can be anticipated that in the near future pan CE of the entire GI tract will be performed, as well as possible tissue acquisition, drug delivery and therapeutic interventions.

Prospective study comparing multi-detector row CT and endoscopy in acute gastrointestinal bleeding

BACKGROUND

Upper and lower acute gastrointestinal bleeding (AGIB) is associated with high rates of mortality and morbidity. The latest computerized tomography (CT) imaging techniques play an important role in the treatment of this pathology.

METHODS

Twenty-nine patients with severe AGIB (11 upper, 18 lower), all hemodynamically stable, underwent endoscopy followed by a multi-detector row CT (MDCT) scan. Endoscopic and MDCT accuracy for the anatomical localization and etiology of AGIB was assessed, the diagnosis being considered correct when the two procedures were concordant or when the diagnosis was confirmed by angiographic, surgical, or post-mortem findings.

RESULTS

The sensitivity in identifying the site and etiology of bleeding was, respectively, 100% and 90.9% for the MDCT scan, compared with 72.7% and 54.5% for endoscopy in upper AGIB, and 100% and 88.2% for the MDCT scan, compared with 52.9% and 52.9% for endoscopy, in lower AGIB.

CONCLUSIONS

Considering the advantages of MDCT over endoscopy, we propose a new diagnostic algorithm for AGIB.

Capsule endoscopy

Capsule endoscopy (CE) is a simple, safe, non-invasive, reliable technique, well accepted and tolerated by the patients, which allows complete exploration of the small intestine. The advent of CE in 2000 has dramatically changed the diagnosis and management of many diseases of the small intestine, such as obscure gastrointestinal bleeding, Crohn's disease, small bowel tumors, polyposis syndromes, etc. CE has become the gold standard for the diagnosis of most diseases of the small bowel. Lately this technique has also been used for esophageal and colonic diseases.

Acute gastrointestinal bleeding: value of MDCT

Contrast-enhanced multidetector row helical computed tomography (MDCT) scanning is establishing itself as a rapid, noninvasive, and accurate diagnostic method in suspected acute gastrointestinal bleeding. Active bleeding can be depicted as an area of focal high attenuation within the bowel lumen on arterial phase MDCT images. New MDCT technologies facilitate three-dimensional image reconstruction, and higher temporal resolution is available with new MDCT scanner generations. This allows for the acquisition of arterial- and portal-venous phase images of the whole abdomen, revealing potential bleeding sources and simultaneously depict morphological changes in the abdomen, such as intestinal tumors. This article gives an overview of available diagnostic modalities in assessing gastrointestinal (GI) tract hemorrhage, with a special emphasis on new MDCT technology.