Acute non-traumatic disease of the abdominal aorta

A secondary abdominal aorta-duodenal fistula accompanied with acquired Immune Deficiency Syndrome presented with recurrent sepsis: a case report

BACKGROUND

Abdominal aorta-duodenal fistulas are rare abnormal communications between the abdominal aorta and duodenum. Secondary abdominal aorta-duodenal fistulas often result from endovascular surgery for aneurysms and can present as severe late complications.

CASE PRESENTATION

A 50-year-old male patient underwent endovascular reconstruction for an infrarenal abdominal aortic pseudoaneurysm. Prior to the operation, he was diagnosed with Acquired Immune Deficiency Syndrome and Syphilis. Two years later, he was readmitted with lower extremity pain and fever. Blood cultures grew Enterococcus faecium, Salmonella, and Streptococcus anginosus. Sepsis was successfully treated with comprehensive anti-infective therapy. He was readmitted 6 months later, with blood cultures growing Enterococcus faecium and Escherichia coli. Although computed tomography did not show contrast agent leakage, we suspected an abdominal aorta-duodenal fistula. Esophagogastroduodenoscopy confirmed this suspicion. The patient underwent in situ abdominal aortic repair and received long-term antibiotic therapy. He remained symptom-free during a year and a half of follow-up.

CONCLUSIONS

This case suggests that recurrent infections with non-typhoidal Salmonella and gut bacteria may be an initial clue to secondary abdominal aorta-duodenal fistula.

Enhancing the Interpretation of Unenhanced Abdominopelvic CT

Unenhanced abdominopelvic CT is frequently performed in patients who are critically ill or have contraindications to intravenous contrast. These cases can be challenging to interpret for the radiologist. Attention to CT physics and care in optimizing image viewing through techniques such as windowing can maximize diagnostic yield. In this case-based review, we will discuss the CT physics concepts of attenuation, common indications and reasons for unenhanced abdominopelvic CT, and review its utility through a series of illustrative cases.

Emergent Magnetic Resonance Angiography for Evaluation of the Thoracoabdominal and Peripheral Vasculature

Thoracoabdominal and peripheral vasculature pathologies include a variety of severe and life threatening conditions that may be encountered in the emergent setting. Computed tomography angiography (CTA) is the first-line modality for imaging of the vasculature in this context, but magnetic resonance angiography (MRA) also plays an important and emerging role in the evaluation of carefully selected patients. Intravenous (IV) iodinated contrast is necessary for CTA, although MRA is most useful in patients who cannot receive IV iodinated contrast for reasons including prior severe allergic-like reaction to iodinated contrast, poor IV access, or severe renal insufficiency. Gadolinium-based contrast agents are administered for MRA when possible, as they generally improve the diagnostic quality and shorten the duration of the exam. In most clinical situations, however, noncontrast MRA is sufficient to obtain a diagnostic evaluation. In this review, we discuss the key strengths and limitations of MRA performed in the emergent setting, highlighting the role of MRA in the diagnosis of acute aortic syndromes, aortitis, aortic aneurysm, pulmonary embolism, and peripheral vascular disease.

Primary aortoenteric fistula: A case report and brief review of the literature

Aortoenteric fistula is a life-threatening emergency and is associated with high morbidity and mortality. Prompt surgical intervention before the aneurysm ruptures lowers the mortality rate to about 50%. Potential imaging mimics for aortoenteric fistula include retroperitoneal fibrosis, mycotic aortic aneurysm, and infectious aortitis. Secondary aortoenteric fistula has relative higher incidence compared to primary and is more common with open aortic repair versus endovascular stent graft repair. Ectopic gas in the aneurysm sac and extravasation of enteric contrast into the aneurysm sac is diagnostic for aortoenteric fistula. However, enteric contrast is not recommended for routine evaluation of aortoenteric because the aforementioned finding is extremely rare. More common imaging findings include bowel loop appearing adherent to aneurysm sac with associated inflammatory stranding and foci or ectopic gas within the aneurysm sac or interposed between the bowel and aneurysm sac. Here we present a case of 52-year-old male who presents with incidental primary aortoenteric fistula.

Role of MRI in the Evaluation of Thoracoabdominal Emergencies

Thoracic and abdominal pathology are common in the emergency setting. Although computed tomography is preferred in many clinical situations, magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) have emerged as powerful techniques that often play a complementary role to computed tomography or may have a primary role in selected patient populations in which radiation is of specific concern or intravenous iodinated contrast is contraindicated. This review will highlight the role of MRI and MRA in the emergent imaging of thoracoabdominal pathology, specifically covering acute aortic pathology (acute aortic syndrome, aortic aneurysm, and aortitis), pulmonary embolism, gastrointestinal conditions such as appendicitis and Crohn disease, pancreatic and hepatobiliary disease (pancreatitis, choledocholithiasis, cholecystitis, and liver abscess), and genitourinary pathology (urolithiasis and pyelonephritis). In each section, we will highlight the specific role for MRI, discuss basic imaging protocols, and illustrate the MRI features of commonly encountered thoracoabdominal pathology.

Extraabdominal Rupture of an Inflammatory Abdominal Aortic Aneurysm in a Patient With Aortodecubital Fistula: A Case Report

Aortodecubital fistula is a pathologic communication between aorta and a decubitus ulcer. It is very rarely encountered vascular condition in abdominal aortic aneurysms (AAA), with difficult diagnostics and high mortality. Patients often present with systemic and local infection and are at risk for hemorrhage. We present a paraplegic patient with fistulous communication between an inflamed abdominal aortic aneurysm and a sacral decubitus ulcer, leading to intermittent bleeding episodes and finally to exsanguination. While extremely rare, this case emphasizes the need for early, accurate diagnosis and salvage intervention when possible.