ACG and SAR release consensus recommendations on the role of imaging for GI bleeding

GI bleeding is the most common GI diagnosis, resulting in hospitalization. Prompt diagnosis and treatment of GI bleeding are improving for improving patient outcomes and reducing high healthcare utilization and costs. Radiologic techniques are frequently used to evaluate GI bleeding patients and complement GI endoscopy. However, multiple management guidelines differ in the recommended utilization of these radiologic examinations. This variability can lead to confusion about using these tests for evaluating GI bleeding.

In the article, published in Radiology, a panel of experts from ACG and SAR reviewed the radiologic examinations used to evaluate for GI bleeding including technique, nomenclature, advantages, performance, and limitations. It also included a comparison of advantages and limitations relative to endoscopic examinations. Finally, consensus statements and recommendations on technical parameters and utilization of radiologic techniques are provided for GI bleeding.

Consensus Recommendations for Imaging in Overt Lower GI Bleeding (LGIB)

CT Angiography

• Unenhanced images (conventional or virtual noncontrast) should be acquired in all cases.
• Images should be acquired during a late arterial phase and a portal venous or delayed phase.
• No oral contrast material should be administered.
• Three-dimensional CTA images can be generated to help guide subsequent conventional angiography.
• Dual-energy CT techniques may be used, if available, to improve the visibility of sites of contrast material extravasation.
• CTA should be performed as the first diagnostic study in hemodynamically unstable patients.
• CTA could be considered the first-line study in hemodynamically stable patients where the suspicion of active bleeding is high.
• CTA is not indicated as a first-line test in hemodynamically stable patients in whom bleeding has subsided.
• A for LGIB can be performed through the common femoral artery or radial artery access.
• Permanent agents, such as microcoils or glue, are used to embolize the vasa recta at the site of identified bleeding.
• In most cases, if CTA is negative for GI bleeding, CA is not indicated.
• In unstable patients with active extravasation at CTA, CA with embolization can be used as the primary treatment modality.
• If the patient has recurrent intermittent LGIB and all modalities have failed to identify the source of bleeding, provocative CA can be performed to identify and treat the culprit lesion.

Catheter Angiography

• A for LGIB can be performed through the common femoral artery or radial artery access.
• Permanent agents, such as micro coils or glue, are used to embolize the vasa recta at the site of identified bleeding.
• In most cases, if CTA is negative for GI bleeding, CA is not indicated.
• In unstable patients with active extravasation at CTA, CA with embolization can be used as the primary treatment modality.
• If the patient has recurrent intermittent LGIB and all modalities have failed to identify the source of bleeding, provocative CA can be performed to identify and treat the culprit lesion.

99mTc-RBC Scan

• The in vitro RBC labeling method has the highest labeling efficiency and is the preferred method.
• Imaging should be continued for 1 hour if no bleeding is detected.
• In a hemodynamically stable patient with evidence of ongoing LGIB, negative evaluation with colonoscopy, and a CTA examination is negative, contraindicated, or not available, tagged RBC scanning can be performed.

Consensus Recommendations for Imaging in Suspected Small Bowel Bleeding

CT Enterography

• CTE should be performed using the multiphase technique in patients older than 40 years of age where vascular lesions are a common cause for bleeding.
• Multiphase CTE should include at least arterial, and enteric or portal venous phases.
• Multiphase CTE is the recommended term for a CTE examination performed for suspected small bowel bleeding and acquired with multiple phases after the administration of intravenous contrast material.
• A single phase performed during the enteric or portal venous phase is adequate to evaluate for inflammatory conditions such as Crohn's disease, radiation enteritis, nonsteroidal anti-inflammatory drug enteropathy, and most malignancies.
• Neutral enteric contrast material should be administered in divided doses beginning 1 hour before CTE.
• CTE should be performed instead of CTA in hemodynamically stable patients presenting with ongoing suspected small bowel bleeding after negative colonoscopy esophagogastroduodenoscopy (EGD), and capsule endoscopy (if negative or not performed).
• If there is brisk ongoing bleeding with hemodynamic instability, CTA should be performed instead of CTE.
• CTE should be the first-line imaging test for suspected small bowel bleeding in hemodynamically stable patients if patients are at increased risk for video capsule retention.
• CTE should be the first-line study for suspected small bowel bleeding in hemodynamically stable patients if small bowel neoplasm is the suspected cause for small bowel bleeding.
• CTE can be performed as the first-line diagnostic study for suspected small bowel bleeding in hemodynamically stable patients depending on clinical scenarios such as local availability and expertise.
• CTE should be performed if there is no definitive cause for small bowel bleeding identified at capsule endoscopy and there is suspicion of ongoing bleeding.

Meckel Scan

Meckel scan can be considered to identify the cause of unexplained intermittent GI bleeding in children and adolescents after negative endoscopic evaluation, including capsule endoscopy if available, and cross-sectional evaluation of the small bowel.

Consensus Recommendations for Imaging in Nonvariceal UGIB

• CA with intent to treat is indicated when an EGD is unsuccessful in achieving initial hemostasis, or the patient experiences recurrent bleeding after a successful initial EGD and a repeat EGD is either unsuccessful or not recommended.
• In the setting of ongoing bleeding, CTA can be considered:
• If the patient is not thought to be suitable for EGD or if there is no in-house emergency gastroenterology coverage.
• After negative EGD or if EGD is unable to identify the site of bleeding.

Reference:

Sengupta N, Kastenberg DM, Bruining DH, Latorre M, Leighton JA, Brook OR, Wells ML, Guglielmo FF, Naringrekar HV, Gee MS, Soto JA, Park SH, Yoo DC, Ramalingam V, Huete A, Khandelwal A, Gupta A, Allen BC, Anderson MA, Dane BR, Sokhandon F, Grand DJ, Tse JR, Fidler JL. The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations. Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298. PMID: 38441091.