Ultrasound evaluation of abdominal aortic and iliac aneurysms and mesenteric ischemia

Imaging and Biomarkers in Acute Aortic Syndromes: Diagnostic and Prognostic Implications

Acute aortic syndrome (AAS) is an emergency and life-threatening condition including aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer and iatrogenic-traumatic aortic injury. An integrated multiparametric approach (clinical history and examination, electrocardiogram, biomarkers and imaging techniques) is recommended in order to make timely and accurate diagnosis, delineate the prognosis, choose the most appropriate therapeutic interventions tailored for the individual patient. Nowadays the best imaging strategy for diagnosing AAS and its complications is a combination of transthoracic echocardiography and computed tomography angiography (CTA). Transesophageal echocardiography tends to be carried out in complicated cases prior to surgical or endovascular therapy, often in the operating room and under general anesthesia. In this regard, intravascular ultrasound and intraluminal phase array imaging may be implemented during the endovascular procedures depending on operator expertise and cost issues. On the other hand, owing to its intrinsic characteristics, magnetic resonance imaging is an ideal imaging technique for serial measurements in patients at risk of AAS or with chronic dissection. Among biomarkers, D-dimer is the closest to "golden status" (high sensitivity and low negative likelihood ratio). Interestingly, 18fluorodeoxyglucose positron emission tomography/CT is increasingly being used along with specific serologic biomarkers (white blood cells, C-reactive protein, fibrinogen and D-dimer) to detect and monitor vascular inflammation affecting the aorta and systemic arteries. It is expected, in the near future, the development of serologic and imaging biomarkers able to early detect clinically-silent pathologic changes in the aorta wall before (primary prevention) and after (secondary prevention) the acute index event.

Role of multidetector CT angiography in the evaluation of suspected mesenteric ischemia

OBJECTIVE

To assess the role of multidetector CT angiography (MDCTA) in the diagnosis of acute mesenteric ischemia (AMI) and to compare the diagnostic utility of axial images with reconstructed images.

MATERIALS AND METHODS

In this Institute Review Board approved prospective study, MDCTA was performed on 31 patients who presented with the clinical suspicion of AMI (25M; 6F, age range: 16-73 years). Axial and reconstructed images of each patient were evaluated independently by two radiologists for evidence of bowel wall thickening, abnormal mucosal enhancement, bowel dilatation or obstruction, mesenteric stranding, ascites, solid organ infarcts, pneumatosis intestinalis or porto-mesenteric gas, and mesenteric arterial or venous occlusion. MDCT findings were correlated with the surgical findings and clinical outcome. Patients were later divided into two groups: a study group of patients with proven AMI and a control group of patients with an alternate diagnosis, for the purpose of statistical analysis.

RESULTS

AMI was correctly diagnosed in all 16 patients on MDCTA (100% sensitivity and specificity) of whom nine patients underwent surgical exploration. Three patients expired before surgery and the remaining 5 patients were proven based on positive clinical and laboratory findings. Mesenteric arterial occlusion was seen in 7 patients while 5 patients had portomesenteric venous thrombosis. Reconstructed images using minimum intensity projection, volume rendering and multiplanar volume reconstruction were found to perform better for the detection of vascular abnormalities and improved the diagnostic confidence of both radiologists in the evaluation of bowel and mesenteric abnormalities.

CONCLUSION

MDCTA is an effective non-invasive modality for the diagnosis of mesenteric ischemia.

High-risk chief complaints III: abdomen and extremities

Abdominal and extremity complaints are a frequent reason for presentation to the emergency department. Although these are common complaints, several abdominal and extremity disease entities may be missed or may be subject to delayed diagnosis. This article provides an overview of the diagnosis and management of several high-risk abdominal and extremity complaints, including appendicitis, abdominal aortic aneurysm, mesenteric ischemia, bowel obstruction, retained foreign body, hand and finger lacerations, fractures, and compartment syndrome. Each section focuses primarily on the pitfalls in diagnosis by highlighting the limitations of history, physical examination findings, and diagnostic testing and provides specific risk management strategies.

Abdominal aortic aneurysm presenting as back pain to a chiropractic clinic: a case report

OBJECTIVE

The aim of this study was to discuss a patient with abdominal aortic aneurysm (AAA) who presented to a chiropractic teaching clinic and review the pathophysiology, therapeutic strategies, and complications associated with treatment of AAA.

CLINICAL FEATURES

A 69-year-old male patient experienced right-sided low back pain with radiation into the right leg for 3 weeks. The radiologic examination of the lumbar spine showed a 7.0-cm AAA and degenerative joint disease in the lumbar spine. Real-time ultrasonography showed an approximately 6.0-cm (transverse diameter), 4.1-cm (anteroposterior diameter), and approximately 7.0-cm (long) infrarenal AAA. Computed tomographic angiography showed additional bilateral iliac artery aneurysms.

INTERVENTION AND OUTCOME

This patient was treated with an endovascular stent graft repair of the abdominal aorta and bilateral iliac artery aneurysms. He has done well after surgery.

CONCLUSION

This article provides a case study and an overview of AAA. Rupture of an aortic aneurysm is preventable by cautious surveillance and the recognition of suspicious physical and radiographic findings in the population at risk. Early detection reduces mortality because repair is elective rather than emergent.