Detection of bleeding due to small bowel cholesterol emboli using helical CT examination in gastrointestinal bleeding of obscure origin

Provocative mesenteric angiography for occult gastrointestinal bleeding: a systematic review

Occult gastrointestinal bleeding (GIB) is a challenge for physicians to diagnose and treat. A systematic literature search of the PubMed and Embase databases was conducted up to January 1, 2023. Eligible studies included primary research studies with patients undergoing provocative mesenteric angiography (PMA) for diagnosis or localization of occult GIB. Twenty-seven articles (230 patients) were included in the review. Most patients (64.8%) presented with lower GIB. The average positivity rate for provocative angiography was 48.7% (58% with heparin and 46.7% in thrombolytics). Embolization was performed in 46.4% of patients, and surgical management was performed in 37.5%. Complications were rare. PMA can be an important diagnostic and treatment tool but studies with high-level evidence and standardized protocols are needed to establish its safety and optimal use.

Upper endoscopy in patients with acute myocardial infarction and upper gastrointestinal bleeding: results of a decision analysis

BACKGROUND

The management of patients with acute myocardial infarction (AMI) and upper gastrointestinal bleeding (UGIB) can present a challenge. The utility of upper endoscopy (esophagogastroduodenoscopy, EGD) and endoscopic therapy must be weighed against safety considerations.

AIM

To assess the utility and safety of EGD in patients with UGIB and AMI.

METHODS

Using decision analysis, patients with UGIB and AMI were assigned to one of two strategies: (1) EGD prior to cardiac catheterization (EGD strategy) and (2) cardiac catheterization without EGD (CATH strategy).

RESULTS

In patients with overt UGIB, the EGD strategy resulted in 97 deaths per 10,000 patients, compared with 600 deaths in the CATH strategy. The EGD strategy resulted in fewer non-fatal complications (1,271 vs. 6,000 per 10,000 patients). In patients with occult blood loss, the EGD strategy resulted in more deaths (59 vs. 16 per 10,000) and more non-fatal complications (888 vs. 160 per 10,000) than the CATH strategy.

CONCLUSIONS

Our analysis supports EGD prior to cardiac catheterization in patients with AMI and overt UGIB. This strategy results in fewer deaths and complications compared with a strategy of proceeding directly to catheterization. Our analysis does not support routine EGD prior to cardiac catheterization in patients with fecal occult blood.

Hemorrhage control using high intensity focused ultrasound

Hemorrhage control is a high priority task in advanced trauma care, because hemorrhagic shock can result in less than a minute in cases of severe injuries. Hemorrhage was found to be solely responsible for 40-50% of traumatic civilian and battlefield deaths in recent years. The majority of these deaths were due to abdominal and pelvic injuries with hidden and inaccessible bleeding of solid organs such as liver, spleen, and kidneys, as well as major blood vessels. High intensity focused ultrasound (HIFU) offers a promising method for hemorrhage control. An important advantage of HIFU is that it can deliver energy to deep regions of tissue where hemorrhage is occurring, allowing cauterization at depth of parenchymal tissues, or in difficult-to-access anatomical regions, while causing no or minimal biological effects in the intervening and surrounding tissues. Moreover, HIFU can cause both thermal and mechanical effects that are shown to work synergistically for rapid hemorrhage control. The major challenges of this method are in development of bleeding detection techniques for accurate localization of the injury sites, delivery of large HIFU doses for profuse bleeding cases, and ensuring safety when critical structures are in the vicinity of the injury. Future developments of acoustic hemostasis technology are anticipated to be for applications in peripheral vascular injuries where an acoustic window is usually available, and for applications in the operating room on exposed organs.

Detection of bleeding in injured femoral arteries with contrast-enhanced sonography

OBJECTIVE

The purpose of this study was to investigate the feasibility of detecting acute arterial bleeding by means of contrast-enhanced sonography.

METHODS

Puncture injury was produced transcutaneously with an 18-gauge needle in 26 femoral arteries (13 in the control group and 13 in the contrast-enhanced group) of rabbits. A sonographic contrast agent (Optison; Mallinckrodt Inc, St Louis, MO) was administered intravenously at a dose of 0.06 to 0.07 mL/kg. Sonography of the femoral arteries was performed before and after injury, both before and after injection of Optison, with B-mode imaging, color Doppler imaging, and pulse inversion harmonic imaging (PIHI).

RESULTS

The specific location of active bleeding could not be visualized in B-mode and PIHI scans in the control group (no Optison injection). After administration of Optison, the bleeding site was visualized because of the increased echogenicity of the extravasated blood at the puncture site in both B-mode imaging and PIHI. In color Doppler images, bleeding sites were localized successfully in 84.6% of the cases in the presence of Optison and in 30.8% of the cases without Optison. Histologic examination (light microscopy) of the hematoma confirmed the presence of contrast agent microbubbles in the extravascular space surrounding the artery.

CONCLUSIONS

Contrast-enhanced sonography may provide an effective method for detecting arterial bleeding.

Obscure gastrointestinal bleeding

Obscure GI bleeding is a relatively common problem facing internists, gastroenterologists, and surgeons in a typical clinical practice. The etiology is occasionally suggested by the patient's age, history, and medications. Management is complicated and typically requires a team-oriented approach, with input from the internist, gastroenterologist, radiologist, and surgeon alike. SBFT and enteroclysis seem to have a limited role, unless there is a high suspicion of a small bowel mass lesion or Crohn's disease. Scintigraphy may be performed in patients with active bleeding in whom endoscopy has failed oris contraindicated. Angiography may be used in patients with an early positive nuclear imaging or failed endoscopic therapy. Provocative angiography probably has a lower diagnostic yield than previously reported, and should be performed only in experienced centers. Helical CT is a new and potentially important option in patients with obscure bleeding, but is currently considered experimental. All patients with obscure GI bleeding should undergo repeat upper endoscopy and perhaps colonoscopy to rule out missed lesions. SBE seems to be complementary to capsule endoscopy, and it is unknown whether this should be performed before capsule endoscopy or only if capsule endoscopy yields a positive proximal small bowel finding. Double balloon enteroscopy seems promising, but the technique requires further study. Surgery should be reserved for patients who have a positive capsule endoscopy requiring surgical therapy or patients who have persistent GI bleeding requiring recurrent blood transfusions in whom all other modalities have failed. Treatment for vascularectasias, the most common cause of obscure GI bleeding, is currently inadequate,and typically requires a combination of multiple management approaches.

An initial experience: using helical CT imaging to detect obscure gastrointestinal bleeding

Obscure gastrointestinal (GI) bleeding is a common but frustrating disease for clinicians because of its elusive nature despite extensive work-up. We evaluate the role of helical computed tomography (CT) imaging using rapid infusion of intravenous contrast and water as oral contrast in the work-up of patients who are actively bleeding. Helical CT may be a useful noninvasive, alternative study to consider when routine work-up fails to determine the cause of active GI bleeding. Our preliminary study shows that helical CT was able to identify a wide variety of causes of obscure GI bleeding.

Cholesterol crystal embolization (CCE) after cardiac catheterization: a case report and a review of 36 cases in the Japanese literature

Cholesterol crystal embolization (CCE) is a complication of atherosclerosis. A 67-year-old Japanese man underwent coronary artery bypass grafting. After the surgery, he underwent coronary angiography via the right femoral artery. Twelve days later, he suddenly developed acalculous cholecystitis and was treated with antibiotics. Gradual deterioration in renal function, purplish discoloration of the distal portion of his toes, and eosinophilia were noted. We performed a skin biopsy and made a diagnosis of CCE. Cilostazol and intravenous heparin improved the symptoms and decreased the creatinine level. We retrospectively studied the clinical features of 36 cases registered with a diagnosis of CCE in the Japanese literature.

Recent advances in small-bowel imaging: a review

This review outlines technical advances in imaging of the small bowel. These include enhancement characteristics of normal bowel mucosa in computed tomography, contrast agents in magnetic resonance imaging, contrast ultrasonography, small-bowel transit measurements by radionuclide imaging, and enteroscopy. Subsequently, the application of these in clinical problem areas, including small-bowel obstruction, bleeding, and Crohn and celiac disease, will indicate the excellent potential of computed tomography, magnetic resonance imaging, and enteroscopy in particular.