Imaging of gastrointestinal bleeding. Surg Clin North Am. 2011;91:93-108. [PMID: 21184902 DOI: 10.1016/j.suc.2010.10.014]

ACR Appropriateness Criteria® Nonvariceal Upper Gastrointestinal Bleeding

Upper gastrointestinal bleeding (UGIB) remains a significant cause of morbidity and mortality with mortality rates as high as 14%. This document addresses the indications for imaging UGIB that is nonvariceal and unrelated to portal hypertension. The four variants are derived with respect to upper endoscopy. For the first three, it is presumed that upper endoscopy has been performed, with three potential initial outcomes: endoscopy reveals arterial bleeding source, endoscopy confirms UGIB without a clear source, and negative endoscopy. The fourth variant, "postsurgical and traumatic causes of UGIB; endoscopy contraindicated" is considered separately because upper endoscopy is not performed. When endoscopy identifies the presence and location of bleeding but bleeding cannot be controlled endoscopically, catheter-based arteriography with treatment is an appropriate next study. CT angiography (CTA) is comparable with angiography as a diagnostic next step. If endoscopy demonstrates a bleed but the endoscopist cannot identify the bleeding source, angiography or CTA can be typically performed and both are considered appropriate. In the event of an obscure UGIB, angiography and CTA have been shown to be equivalent in identifying the bleeding source; CT enterography may be an alternative to CTA to find an intermittent bleeding source. In the postoperative or traumatic setting when endoscopy is contraindicated, primary angiography, CTA, and CT with intravenous contrast are considered appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Use of radiopharmaceuticals in diagnostic nuclear medicine in the United States: 1960-2010

To reconstruct reliable nuclear medicine-related occupational radiation doses or doses received as patients from radiopharmaceuticals over the last five decades, the authors assessed which radiopharmaceuticals were used in different time periods, their relative frequency of use, and typical values of the administered activity. This paper presents data on the changing patterns of clinical use of radiopharmaceuticals and documents the range of activity administered to adult patients undergoing diagnostic nuclear medicine procedures in the U.S. between 1960 and 2010. Data are presented for 15 diagnostic imaging procedures that include thyroid scan and thyroid uptake; brain scan; brain blood flow; lung perfusion and ventilation; bone, liver, hepatobiliary, bone marrow, pancreas, and kidney scans; cardiac imaging procedures; tumor localization studies; localization of gastrointestinal bleeding; and non-imaging studies of blood volume and iron metabolism. Data on the relative use of radiopharmaceuticals were collected using key informant interviews and comprehensive literature reviews of typical administered activities of these diagnostic nuclear medicine studies. Responses of key informants on relative use of radiopharmaceuticals are in agreement with published literature. Results of this study will be used for retrospective reconstruction of occupational and personal medical radiation doses from diagnostic radiopharmaceuticals to members of the U.S. radiologic technologists' cohort and in reconstructing radiation doses from occupational or patient radiation exposures to other U.S. workers or patient populations.

Small bowel bleeding: a comprehensive review

The small intestine is an uncommon site of gastro-intestinal (GI) bleeding; however it is the commonest cause of obscure GI bleeding. It may require multiple blood transfusions, diagnostic procedures and repeated hospitalizations. Angiodysplasia is the commonest cause of obscure GI bleeding, particularly in the elderly. Inflammatory lesions and tumours are the usual causes of small intestinal bleeding in younger patients. Capsule endoscopy and deep enteroscopy have improved our ability to investigate small bowel bleeds. Deep enteroscopy has also an added advantage of therapeutic potential. Computed tomography is helpful in identifying extra-intestinal lesions. In cases of difficult diagnosis, surgery and intra-operative enteroscopy can help with diagnosis and management. The treatment is dependent upon the aetiology of the bleed. An overt bleed requires aggressive resuscitation and immediate localisation of the lesion for institution of appropriate therapy. Small bowel bleeding can be managed by conservative, radiological, pharmacological, endoscopic and surgical methods, depending upon indications, expertise and availability. Some patients, especially those with multiple vascular lesions, can re-bleed even after appropriate treatment and pose difficult challenge to the treating physician.

Factors predictive for a positive invasive mesenteric angiogram following a positive CT angiogram in patients with acute lower gastrointestinal haemorrhage

INTRODUCTION

Computed tomographic mesenteric angiography (CTMA) is increasingly adopted in patients with massive lower gastrointestinal (LGI) bleeding. However, a positive computed tomography scan does not always translate to a positive invasive mesenteric angiography (MA) when performed. The aim of this study was to identify factors that could predict a positive invasive MA following a positive CTMA.

METHODS

A review of all patients with LGI haemorrhage who had a positive CTMA followed by an invasive MA was performed.

RESULTS

From July 2009 to October 2012, 33 positive CTMA scans from 30 patients were identified. Of the 33 bleeding points, 28 were in the colon, while 5 were in the small intestine. Diverticular disease accounted for 20 of the bleeding points. The median duration from the CTMA to the invasive MA was 165 (74-614) min. Of the 33 invasive MAs that were performed, only 14 demonstrated positive extravasation. Factors that were significant for a positive invasive MA included non-diverticular aetiology (odds ratio (OR), 6.75, 95 % confidence interval (CI), 1.43-31.90, p = 0.029) and haemoglobin <100 g/l (OR, 14.44, 95 % CI, 1.56-133.6, p = 0.009). When the invasive MA procedure was performed within <150 min of the positive CTMA scan, it was 2.89 (95 % CI, 0.69-12.12) times more likely to be associated with a positive invasive MA.

CONCLUSIONS

Patients with non-diverticular aetiologies and lower haemoglobin levels are associated with a positive invasive MA following a positive CTMA. It is prudent to consider performing the invasive MA within 150 min after a positive CTMA.

The safety and efficacy of mesenteric embolization in the management of acute lower gastrointestinal hemorrhage

Purpose

Mesenteric embolization is an integral part in the management of acute lower gastrointestinal (GI) bleeding. The aim of this study was to highlight our experience after adopting mesenteric embolization in the management of acute lower GI hemorrhage.

Methods

A retrospective review of all cases of mesenteric embolization for acute lower GI bleeding from October 2007 to August 2012 was performed.

Results

Twenty-seven patients with a median age of 73 years (range, 31 to 86 years) formed the study group. More than half (n = 16, 59.3%) of the patients were on either antiplatelet and/or anticoagulant therapy. The underlying etiology included diverticular disease (n = 9), neoplasms (n = 5) and postprocedural complications (n = 6). The colon was the most common bleeding site and was seen in 21 patients (left, 10; right, 11). The median hemoglobin prior to the embolization was 8.6 g/dL (6.1 to 12.6 g/dL). A 100% technical success rate with immediate cessation of hemorrhage at the end of the session was achieved. There were three clinical failures (11.1%) in our series. Two patients re-bled, and both underwent a successful repeat embolization. The only patient who developed an infarcted bowel following embolization underwent an emergency operation and died one week later. There were no factors that predicted clinical failure.

Conclusion

Mesenteric embolization for acute lower GI bleeding can be safely performed and is associated with a high clinical success rate in most patients. A repeat embolization can be considered in selected cases, but postembolization ischemia is associated with bad outcomes.

Application of anisodamine to emergency digital subtraction angiography for abdominal organ hemorrhage

AIM: To explore the value of anisodamine applied to emergency digital subtraction angiography (DSA) for abdominal organ hemorrhage.

METHODS: Thirty-three patients with gastrointestinal or kidney hemorrhage underwent emergency DSA. Arterial injection of 10 mg of anisodamine was employed before angiography. DSA images were acquired during free breathing and post-processed using re-mask function.

RESULTS: Artifacts caused by gastrointestinal peristalsis were reduced remarkably. The image quality was satisfactory in all cases. Bleeding signs were presented in 27 cases (81.82%) and endovascular embolization was performed after superselective catheterization of the lesioned vessels.

CONCLUSION: The use of anisodamine before angiography can improve the quality of images acquired by emergency DSA for abdominal organ hemorrhage.

Surgical management of lower gastrointestinal bleeding

PURPOSE

Lower gastrointestinal bleeding (LGIB) is any form of bleeding distal to the Ligament of Treitz. In most cases, acute LGIB is self-limited and resolves spontaneously with conservative management.

METHODS

Only a minority of approximately 10% is admitted to hospital with signs of massive bleeding and shock requiring resuscitation, urgent evaluation and treatment.

RESULTS

Over the past decade, there has been a progressive decrease in upper GI events and a significant increase in lower GI events. Overall, mortality has also decreased, but in-hospital fatality due to upper or lower GI complications have remained constant. The problem is that LGIB can arise from a number of sources and may be a significant cause of hospitalisation and mortality in elderly patients.

CONCLUSIONS

After initial resuscitation, the diagnosis and treatment of LGIB remains a challenge for acute care surgeons, whereby the identification of the source of bleeding is of utmost importance.