Contemporary Approaches to the Management of Neurosurgical Complications of Infective Endocarditis

Ultrasound-based imaging in neurocritical care patients: a review of clinical applications

OBJECTIVE

To analyze the diagnostic, monitoring, and procedural applications of ultrasound (US) imaging in neurocritical care (NCC) patients.

METHOD

US imaging has been extensively validated in various subset of critically ill patients, but not specifically in the NCC population. We reviewed the clinical applications of US imaging for heart, vascular, brain, and lung evaluation and for possible procedural uses in NCC patients. Major neurosurgical books, journals, testimonials, authors' personal experience, and scientific databases were analyzed.

RESULTS

Cardiac US imaging provides accurate information at NCC arrival to stratify risk factors, including presence of atrial septal defect/patent formen ovale, abnormal ventricular function, or pericardial effusion, and to monitor cardiac anatomy and function during the NCC stay for guiding goal-directed therapy. Vascular US in NCC patients has three especially relevant indications: to screen anatomy and flow in extracranial supra-aortic arteries, to diagnose deep vein thrombosis, and to optimize the safety of central venous catheterization. Brain US has important clinical applications in the NCC, including transcranial Doppler and emerging techniques for cerebral blood flow evaluation with contrast-enhanced US imaging. Lung US, as demonstrated in other intensive care unit patients, provides accurate diagnosis of anatomical and functional abnormalities and enables diagnosis of pleural effusion, pneumothorax, lung consolidation, pulmonary abscess and interstitial-alveolar syndrome, and lung recruitment/derecruitment. US imaging can effectively guide percutaneous tracheostomy.

CONCLUSION

In conclusion, US imaging is an important diagnostic tool that provides real-time information at the bedside to stratify risk, monitor for complications, and guide invasive procedures in NCC patients.

Endovascular intervention for acute stroke due to infective endocarditis

The overall incidence of neurological complications due to infective endocarditis is as high as 40%, with embolic infarcts more common than hemorrhagic strokes. The standard of care for typical strokes does not apply to infective endocarditis because there is a substantial risk of hemorrhage with thrombolysis. In the last decade there have been multiple case reports of intravenous and intraarterial thrombolysis with successful outcomes for acute strokes with related infective endocarditis, but successful endovascular interventions for acute strokes associated with infective endocarditis are rarely reported. To the authors' knowledge, this report is the first case in the literature to use a mechanical retrieval device in successful vegetation retrieval in an infective endocarditis acute stroke. Although an interventional approach for treatment of acute stroke related to infective endocarditis is a promising option, it is controversial and a cautious clinical decision should be made on a case-by-case basis. The authors conclude that this approach can be tested in a case series with matched controls, because this condition is rare and a randomized clinical trial is not a realistic option.

Early Endovascular Coiling of Posterior Communicating Artery Saccular Aneurysm in the Setting of Staphylococcus Bacteremia

OBJECTIVE

Although infectious complications of endovascular aneurysm treatment are in general rare, platinum coil therapy for patients with ruptured cerebral aneurysms and active bacteremia could be expected to carry increased risk. The literature on the timing and safety of endovascular treatment in this setting, however, is limited. In this report, the authors present a case of aneurysmal subarachnoid hemorrhage and active bacteremia in which intravenous antibiotics and early endovascular therapy were successfully used. A review of the literature is also provided.

CLINICAL PRESENTATION

A 79-year-old woman presented with Hunt-Hess grade 4, Fisher grade 3 + 4 subarachnoid hemorrhage. Blood cultures obtained on admission revealed gram-positive cocci, which later proved to be coagulase-negative Staphylococcus.

INTERVENTION

Intravenous cefepime and vancomycin were begun soon after admission. A right posterior communicating artery saccular aneurysm was identified on diagnostic cerebral angiography and was treated with bare platinum coils 28 hours after antibiotic therapy was initiated. An extended course of vancomycin was completed. No intracranial infectious complications were noted at 34-month clinical and radiographic follow-up.

CONCLUSION

This is the first case report to document the efficacy and safety of early endovascular coil embolization of a ruptured saccular cerebral aneurysm presenting in the context of active bacteremia. Review of the available literature suggests that a similar strategy for ruptured infectious aneurysms may also be safe. Further validation of this approach for both saccular and infectious aneurysms, however, is required.

Central nervous system infections in injection drug users

Central nervous system infections in injection drug users are often devastating in terms of excess morbidity and mortality. In injection drug users with infective endocarditis, embolization from infected valvular vegetations may cause cerebral infarction, intracranial hemorrhage, and the formation of brain abscess. Focal intracranial infections (i.e., brain abscess and spinal epidural abscess) may occur in the absence of infective endocarditis, resulting from bacteremia that seeds the brain or epidural space. Antimicrobial therapy, combined with surgical intervention, may be essential to improve outcome from these neurologic complications. Toxin-mediated diseases (especially tetanus and wound botulism) are also seen in injection drug users. Inoculation of Clostridium spp at injection sites may lead to toxin generation and disease. Clinicians must maintain a high level of suspicion for these diagnoses in injection drug users.