Multi‐detector CT angiography for lower gastrointestinal bleeding: Can it select patients for endovascular intervention?

Abstract

Summary This is a retrospective review of the results at our institution of using multi‐detector CT angiography (CTA) to localise lower gastrointestinal (GI) bleeding. We hypothesised that in our patient population: (i) CTA was unlikely to demonstrate bleeding in patients who were haemodynamically stable; (ii) in haemodynamically unstable patients in whom CTA was undertaken, the results could be used to select patients who would benefit from catheter angiography; and (iii) in haemodynamically unstable patients in whom CTA was undertaken, a subgroup of patients could be identified who would benefit from primary surgical treatment, avoiding invasive angiography completely. A retrospective review was conducted of the clinical records of all patients undergoing CTA for lower GI haemorrhage at our institution between 1 January 2005 and 30 June 2007. Out of the 20 patients examined, 10 had positive CTAs demonstrating the bleeding site. Nine were haemodynamically unstable at the time of the study. Four patients with positive CT angiograms were able to be treated directly with surgery and avoided invasive angiography. Ten patients had negative CTAs. Four of these were haemodynamically unstable, six haemodynamically stable. Only one required intervention to secure haemostasis, the rest stopped spontaneously. No haemodynamically stable patient who had a negative CTA required intervention. CTA is a useful non‐invasive technique for localising the site of lower GI bleeding. In our patient population, in the absence of haemodynamic instability, the diagnostic yield of CTA was low and bleeding was likely to stop spontaneously. In haemodynamically unstable patients, a positive CTA allowed patients to be triaged to surgery or angiography, whereas there was a strong association between a negative CTA and spontaneous cessation of bleeding.

Outcome Following a Negative CT Angiogram for Gastrointestinal Hemorrhage

“…Foley et al [6] recommended CTA as a primary imaging modality in unstable patients with GI hemorrhage as a positive CTA can guide a patient's subsequent intervention, whereas patients with a negative CTA are more likely to settle spontaneously.…”

Quality Improvement Guidelines for Transcatheter Embolization for Acute Gastrointestinal Nonvariceal Hemorrhage

“…In addition, compared to conventional angiography, it is able to depict surrounding anatomical structures and to determine not only the place, but also a possible cause of bleeding. MDCT angiography also displays the complete vascular anatomy and may allow better planning of subsequent endovascular intervention [17]. It is generally recommended to include precontrast scans before IV contrast injection to differentiate blood from other high-density material in the bowel.…”

Radiographic techniques for the localization and treatment of gastrointestinal bleeding of obscure origin

“…In these cases, in our opinion, a CTA must be done. CTA is an excellent non-invasive method with sensitivities in detecting obscure GIB reported up to 100% [18,33,34,39,40,45]. The only diagnostic method in detecting obscure GIB with a higher sensitivity is TRBC, which is not very useful in an acute situation, as it is very timeconsuming.…”

“…Less specific signs have been reported, such as bowel wall thickening, contrast enhancement of the bowel wall, or high density of the peribowel fat [33,39,40].…”

“…Other authors make a positive diagnosis based on the comparison between the precontrast and postcontrast, including a native scan before arterial-phase scans [39,41].…”