From the Guidelines
Evaluation for mycotic (fungal) aneurysm should include imaging studies such as cerebral CT scan or MRI, as well as TTE or TOE, to detect intracranial infectious aneurysms in patients with infective endocarditis and neurological symptoms.
Evaluation Approach
- Clinical assessment is crucial in evaluating patients with suspected mycotic aneurysms, particularly those with infective endocarditis (IE) and neurological symptoms 1.
- Imaging studies, including:
- Cerebral CT scan
- MRI
- TTE (transthoracic echocardiography)
- TOE (transoesophageal echocardiography) are essential for detecting intracranial infectious aneurysms in patients with IE and neurological symptoms 1.
Key Considerations
- Intracranial location is most common, with a reported frequency of 2-4%, although this may be an underestimation since some infectious aneurysms are clinically silent 1.
- Early detection and treatment of infectious aneurysms are essential due to the high morbidity and mortality rate secondary to rupture 1.
- Clinical presentation is highly variable, including focal neurological deficit, headache, confusion, seizures, making systematic imaging necessary in cases of IE with neurological symptoms 1.
Diagnostic Imaging Characteristics
- Mycotic aneurysms can be characterized by irregular, lobular, or saccular shape, with less common intimal calcifications and uncommon mural thrombosis 1.
- Periaortic findings, such as stranding, encasing, or contiguous mass, are common in mycotic aneurysms, and the presence of gas is highly suggestive of mycotic aneurysm 1.
Management
- The management of unruptured intracranial aneurysms depends on the risk of rupture, based on absolute size, growth rate, presence of symptoms, and other anatomic characteristics 1.
- For ruptured infectious aneurysm and hemorrhage, surgery is often delayed and based on serial imaging and clinical progression 1.
From the Research
Evaluation for Mycotic (Fungal) Aneurysm
The evaluation for mycotic aneurysm involves various diagnostic approaches to identify the condition and its causative pathogens. The following points highlight the key aspects of evaluation:
- Diagnostic Challenges: Mycotic aneurysms pose diagnostic challenges due to their nonspecific symptoms, such as fever and discomfort 2.
- Imaging Studies: CT and MRI are commonly used imaging modalities for diagnosing mycotic aneurysms, with moderately high sensitivities and specificities 3.
- Diagnostic Performance: The pooled sensitivities and specificities of CT for all mycotic aneurysms were 0.82 and 0.93, respectively, while those of MRI were 0.79 and 0.89, respectively 3.
- Clinical Presentation: Patients with mycotic aneurysms can have wide-ranging clinical presentations, depending on the site of the aneurysm, and may present with non-specific symptoms such as nausea and vomiting 4.
- Risk Factors: Certain patient populations, such as those with immunodeficiency or a history of IV drug use, are at higher risk for developing mycotic aneurysms 4, 5.
- Diagnostic Approach: A comprehensive diagnostic approach, including laboratory tests, imaging studies, and physical examination, is essential for early identification and treatment of mycotic aneurysms 2, 6.
- Treatment Options: Endovascular treatment of mycotic aneurysms is a feasible and durable treatment option, but late infections can occur and warrant long-term antibiotic treatment and follow-up 5.