Endovascular management of cerebral septic embolism: three recent cases and review of the literature

Short-term aneurysm formation and rupture due to septic embolism diagnosed with a thrombus retrieved from another occluded artery

Background:

In rare cases, septic embolism is diagnosed on the basis of pathological findings of retrieved thrombi. Infected aneurysms can rapidly form and rupture after septic embolism, leading to a poor prognosis. We report a case of subcortical hemorrhage due to an infected aneurysm forming shortly after septic embolism in the left anterior cerebral artery.

Case Description:

In this case, the diagnosis of septic embolism was made on the basis of pathological findings of a thrombus retrieved from the simultaneously occluded left middle cerebral artery, and endovascular embolization of the infected aneurysm was performed.

Conclusion:

The pathological findings of a retrieved thrombus were useful for making a diagnosis of septic embolism. The possibility of short-term formation and rupture of an infected aneurysm after septic embolism should be noted. Endovascular embolization of occluded vessels due to septic embolism may prevent aneurysm formation and subsequent bleeding.

Optimal Timing for Cardiac Surgery in Infective Endocarditis with Neurological Complications: A Narrative Review

In patients with infective endocarditis and neurological complications, the optimal timing for cardiac surgery is unclear due to the varied risk of clinical deterioration when early surgery is performed. The aim of this review is to summarize the best evidence on the optimal timing for cardiac surgery in the presence of each type of neurological complication. An English literature search was carried out from June 2018 through July 2022. The resulting selection, comprising observational studies, clinical trials, systematic reviews and society guidelines, was organized into four sections according to the four groups of neurological complications: ischemic, hemorrhagic, infectious, and asymptomatic complications. Cardiac surgery could be performed without delay in cases of ischemic vascular neurological complication (provided the absence of severe damage, which can be avoided with the performance of mechanical thrombectomy in cases of major stroke), as well as infectious or asymptomatic complications. In the presence of intracranial hemorrhage, a delay of four weeks is recommended for most cases, although recent studies have suggested that performing cardiac surgery within four weeks could be a suitable option for selected cases. The findings of this review are mostly in line with the recommendations of the current European and American infective endocarditis guidelines.

Symptomatic Intracranial Artery Stenosis Due to an Unknown Embolus Following Cardiac Surgery: A Case Report

Intracranial artery occlusion due to a foreign body is a complication associated with cardiac surgery that is treated by various techniques. However, little is known about appropriate strategies for symptomatic intracranial artery stenosis due to an unknown embolic source. We reported a case of middle cerebral artery (MCA) stenosis after mitral valve repair (MVR) for infective endocarditis (IE). An 80-year-old man presented with right hemiplegia. MR angiography findings were normal, and diffusion-weighted imaging revealed subtle ischemic change in the left MCA territory. The patient was diagnosed with cardioembolic stroke owing to IE and performed MVR. Four days later, he suddenly presented with consciousness disorder and left hemiplegia. Computed tomography (CT) confirmed a very low-density area within the right MCA. MR angiography revealed right MCA stenosis, which corresponded to the low-density area on CT images. Diffusion-weighted imaging revealed new ischemic change in the right MCA territory. Angiography confirmed an irregular stenosis at the right M2 with antegrade blood flow, and the hemiplegia resolved during angiography. Conservative therapy was performed; however, the resting 123 I-IMP-single photon emission CT revealed moderate perfusion defect in the right MCA territory, and transient left hemiplegia appeared every few days. Therefore, 19 days after the initial transient ischemic attack, the patient was performed superficial temporal artery–MCA anastomosis, and the patient responded with a good clinical course without recurrence of the ischemic symptoms. This strategy may be a safe and effective treatment for symptomatic intracranial artery stenosis due to an unknown embolic source.

Successful Thrombectomy for Endocarditis-Related Stroke in a Very Young Patient: Illustrative Case

Objective

Unlike in older adults, ischemic stroke in young patients occurs secondary to preexisting conditions. Infective endocarditis (IE) is among the most important causes of stroke in young adults and has a severe prognosis. There are few reports of mechanical thrombectomy (MT) for IE-induced large-vessel occlusion (LVO). This paper reports a case of acute IE-induced LVO in a young patient who was successfully treated with MT.

Case Presentation

An 18-year-old woman presented to our hospital with severe headache, high fever, and left fingertip pain. She was admitted to the Department of Neurology for conservative treatment of suspected meningitis. On day 2 of admission, she developed acute left hemiparesis, left hemispatial neglect, and dysarthria. MRA showed occlusion of the right M1 segment of the middle cerebral artery, and the patient immediately underwent MT. After a single pass, we achieved thrombolysis in cerebral infarction 2b. A white clot was diagnosed as a vegetation on pathological examination. As transesophageal echocardiography showed a vegetation on the mitral valve, the patient was diagnosed with IE and underwent cardiovascular surgery. The patient recovered well and underwent additional treatment and rehabilitation.

Conclusion

Although rare, IE-induced septic emboli may occur in young patients with LVO, necessitating MT and pathological diagnosis of the clot.

[Nonrecanalization after mechanical thrombectomy in acute ischemic stroke due to infective endocarditis: an autopsy case]

An 86-year-old man was admitted for the abrupt onset of right hemiparesis and aphasia. DWI revealed the high intensity legion in the left insular cortex, and MRA demonstrated the left middle cerebral artery occlusion. Recanalization of the artery was not achieved after mechanical thrombectomy. The diagnosis of infective endocarditis was made as Enterococcus faecalis was cultured from the blood, and mobile vegetation was detected at the aortic valve by transthoracic echocardiography. The patient died from multiple organ failure at 19 days. Autopsy findings revealed fibrin-rich thrombus in the left middle cerebral artery containing neutrophils and bacteria. At the occluded site, neutrophils had intensively infiltrated into the vessel wall, and endothelial cells had partially disappeared. Moreover, disrupted internal elastic lamina was discovered. These findings could indicate that the thrombus had adhered to the vessel wall. The adhesion of the thrombus and vessel wall could be associated with unsuccessful recanalization after endovascular thrombectomy in patients with ischemic stroke due to infective endocarditis.

Clot Composition Analysis as a Diagnostic Tool to Gain Insight into Ischemic Stroke Etiology: A Systematic Review

Mechanical thrombectomy renders the occluding clot available for analysis. Insights into thrombus composition could help establish the stroke cause. We aimed to investigate the value of clot composition analysis as a complementary diagnostic tool in determining the etiology of large vessel occlusion (LVO) ischemic strokes (International Prospective Register of Systematic Reviews [PROSPERO] registration # CRD42020199436). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we ran searches on Medline (using the PubMed interface) and Web of Science for studies reporting analyses of thrombi retrieved from LVO stroke patients subjected to mechanical thrombectomy (January 1, 2006 to September 21, 2020). The PubMed search was updated weekly up to February 22, 2021. Reference lists of included studies and relevant reviews were hand-searched. From 1,714 identified studies, 134 eligible studies (97 cohort studies, 31 case reports, and six case series) were included in the qualitative synthesis. Physical, histopathological, biological, and microbiological analyses provided information about the gross appearance, mechanical properties, structure, and composition of the thrombi. There were non-unanimous associations of thrombus size, structure, and composition (mainly proportions of fibrin and blood formed elements) with the Trial of Org 10172 in Acute Stroke Treatment (TOAST) etiology and underlying pathologies, and similarities between cryptogenic thrombi and those of known TOAST etiology. Individual thrombus analysis contributed to the diagnosis, mainly in atypical cases. Although cohort studies report an abundance of quantitative rates of main thrombus components, a definite clot signature for accurate diagnosis of stroke etiology is still lacking. Nevertheless, the qualitative examination of the embolus remains an invaluable tool for diagnosing individual cases, particularly regarding atypical stroke causes.

Neurologic complications of infective endocarditis

Infective endocarditis (IE) is an infection primarily affecting the endocardium of heart valves that can embolize systemically and to the brain. Neurologic manifestations include strokes, intracerebral hemorrhages, mycotic aneurysms, meningitis, cerebral abscesses, and infections of the spine. Neurologic involvement is associated with worse mortality, though it does not always portend a poor functional prognosis. Neuroimaging is indicated in patients who have neurologic symptoms, including cerebral vessel imaging in patients who have subarachnoid hemorrhage. In the case of acute ischemic stroke (IS), IV thrombolysis is contraindicated but endovascular thrombectomy may be a consideration. Neurologic findings understandably raise concern about valve surgery when indicated due to the risk of hemorrhage with perioperative anticoagulation. However, most neurologic complications do not preclude valve surgery and valve surgery may in fact be indispensable in some cases to prevent further neurologic problems. Management decisions in patients with IE and neurologic complications should therefore be multidisciplinary with a major contribution from the neurologist.

Endovascular treatment of ischemic large-vessel stroke due to infective endocarditis: case series and review of the literature

BACKGROUND

Mechanical thrombectomy is the standard of care, in selected patients, for acute ischemic stroke with large vessel occlusion but its use in patients with stroke secondary to infective endocarditis is controversial. We report three cases of acute ischemic stroke treated by mechanical thrombectomy and we propose an extensive review of the literature to evaluate the clinical safety and efficacy of thrombectomy in patients with stroke secondary to infective endocarditis.

METHODS

A comprehensive literature search was performed following a pre-specified protocol of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Case reports, cases series, cross-sectional studies, case control studies, randomized controlled trials or nonrandomized controlled trials were considered that included endocarditis-related acute ischemic stroke patients who underwent mechanical thrombectomy.

RESULTS

The database search yielded 431 relevant records published until January 2020. Nineteen articles fulfilled the eligibility criteria that described thirty patients. After the thrombectomy, 13.3% of the patients experienced intracranial haemorrhage. After the procedure, the median National Institutes of Health Stroke Scale score dropped from 15 (IQR 7) to 2.5 (IQR 5.75). At 90 days, mortality was 23.3% while 46.7% of the patients were functionally independent (mRS ≤ 2).

DISCUSSION

Based on our review, the use of mechanical thrombectomy in patients with large vessel occlusion due to endocarditis-associated stroke might improve patient outcome but it should be considered on a case by case base as the safety has not been well established yet. Further research on risk stratification is needed to drive clinician during the decision-making process.

[Therapeutic and endovascular management of cerebral mycotic aneurysms]

Infective endocardites are associated with both ischemic and hemorrhagic neurological complications and also with cerebral abscesses and the development of "mycotic" aneurysms, which are detected in about 5 % of patients in the acute and sub-acute phase of the infection. Data about their natural history and their hemorrhagic risk are scarce and fragmented. The therapeutic management is represented by the medical treatment of the infection with interventional abstention, the surgical treatment and the endovascular approach by selective embolization of the aneurysm. No evidence is provided concerning the superiority of a specific approach. Mycotic aneurysms remain a diagnostic and therapeutic challenge and their management is necessarily based on a multidiscplinary approach.

Early cardiac surgery for infective endocarditis with acute extensive cerebral infarction

Early cardiac surgery was successfully performed on a patient with infective endocarditis and extensive cerebral infarction due to septic embolus, following mechanical embolectomy for proximal middle cerebral artery occlusion. Mechanical embolectomy may be useful for the success of early cardiac surgery in these patients.

Clinical challenges associated with the endovascular treatment of acute stroke in a patient with infective endocarditis

Although stroke is common in infective endocarditis (IE), only 26 cases of thrombectomy have been reported to date for IE-related acute stroke. We report a 40-year-old man who presented with left middle cerebral artery occlusion of unknown cause. Multiple attempts of mechanical aspiration thrombectomy and stentrievers failed to recanalize the artery. Effective revascularization was eventually achieved by placing a self-expanding intracranial stent. Post-procedurally the patient was diagnosed with IE with mitral valve insufficiency, mandating emergent valvular replacement while the patient was still on tirofiban infusion. On follow-up, the patient had a modified Rankin’s score of 0, had no recurrent stroke, and the intracranial stent remained patent yet stenosed. Based on the use of a self-expanding intracranial stent in the setting of IE, we discuss the consequences of the fibrotic and inflammatory content of the embolus and the associated high risk of intracranial hemorrhage which complicates clinical decision making.

Safety and outcomes of mechanical thrombectomy for acute stroke related to infective endocarditis: A case–control study

Background and purpose

Successful reperfusion can be achieved in more than two-thirds of patients with usual large-vessel occlusion stroke causes treated with mechanical thrombectomy. However, the safety and outcomes after mechanical thrombectomy in the setting of large-vessel occlusion related to infective endocarditis is not known. In this study, we investigated the impact of mechanical thrombectomy in infective endocarditis patients on angiographic and clinical outcomes.

Methods

This was a multicenter study from five comprehensive stroke centers. We compared the outcomes of mechanical thrombectomy treated stroke patients due to infective endocarditis with patients presenting atrial fibrillation. Clinical outcomes included 90-day modified Rankin Scale, symptomatic intracerebral hemorrhage, and mortality.

Results

Between June 2013 and March 2019, 28 patients presenting large-vessel occlusion stroke due to IE were included. These cases were matched with 84 large-vessel occlusion stroke related to atrial fibrillation. Successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b/3) was obtained in 85.7%. Symptomatic intracranial hemorrhage, favorable outcome and mortality rates were respectively 8.0%, 25.9%, and 25.9%. In the case–control analysis, we demonstrated no difference in terms of successful reperfusion, procedural complication, symptomatic intracranial hemorrhage, and mortality rates. Three-month favorable outcome was less often achieved in the infective endocarditis group.

Conclusions

Mechanical thrombectomy of infective endocarditis patients presents similar safety and angiographic results compared to patients suffering from atrial fibrillation.

Mechanical Thrombectomy for Acute Ischemic Stroke Secondary to Infective Endocarditis

Intravenous thrombolysis is contraindicated in acute ischemic stroke secondary to infective endocarditis. We report our initial experience in 6 cases of proximal vessel occlusion treated with mechanical thrombectomy, which was safe (no bleeding) and effective (significant early neurological improvement) and might be useful in this clinical setting.

Neurological Complications of Infective Endocarditis

PURPOSE OF REVIEW

The purpose of this narrative review and update is to summarize the current knowledge and provide recent advances on the neurologic complications of infective endocarditis.

RECENT FINDINGS

Neurological complications occur in about one-fourth of patients with infective endocarditis. Brain MRI represents a major tool for the identification of asymptomatic lesions, which occur in most of the patients with infective endocarditis. The usefulness of systematic brain imaging and the preferred treatment of patients with infective endocarditis and silent brain lesions remains uncertain. The basis of treatment of infective endocarditis is early antimicrobial therapy. In stroke due to infective endocarditis, anticoagulation and thrombolysis should be avoided. Endovascular treatment can be useful for both acute septic emboli and mycotic aneurysms, but evidence is still limited. In patients with neurological complications, cardiac surgery can be safely performed early, if indicated. The optimal management of a patients with neurological complications of infective endocarditis needs an individualized case discussion and the participation of a multidisciplinary team including neurologists, cardiologists, cardiothoracic surgeons, neuroradiologists, neurosurgeons, and infectious disease specialists.

A Puzzling Case of Cryptogenic Stroke

BACKGROUND

Stroke is a common neurological complication of infective endocarditis (IE) and it is associated with increased morbidity and mortality but infective endocarditis in acute stroke setting is hard to discover.

MATERIAL AND METHODS

A 75-year-old man referred to hospital for the onset of left hemiparesis and dysarthria. His past medical history included hypertension. He had 3 months history of fatigue, fever, and weight loss. Neurological examination revealed left hemiparesis and dysarthria.

FINDINGS

Brain CT and CT angiography revealed a right M1 segment occlusion. Thrombolysis was delivered followed by mechanical thrombectomy by clot aspiration and recanalization was achieved. Anatomopathological analysis of the clot showed necrotic material and bacterial colonies consistent with septic emboli. The day after he developed fever and brain CT revealed a right parieto-occipital intraparenchymal and subarachnoid hemorrhage. Blood cultures demonstrated growth of Enterococcus faecalis. Treatment with vancomycin and ampicillin was started.

CONCLUSION

Management of acute ischemic stroke related to IE is difficult. The great clinical challenge for the physician is recognizing the signs suggestive of IE in the acute stroke setting. Anatomo-pathological and bacteriological analysis of the clot in patients eligible to mechanical thrombectomy can provide the remarkable advantage to analyse directly the extracted material, allowing an early diagnosis and appropriate antibiotic therapies and treatments.

Successful thrombectomy in endocarditis-related stroke: Case report and review of the literature

Neurological complications of infective endocarditis are frequent, especially ischaemic strokes. As intravenous thrombolysis in infective endocarditis-related ischaemic stroke has a controversial benefit/risk ratio, alternative treatment regimens have to be considered. We present the case of a young patient with septic embolism of the middle cerebral artery who was successfully treated with mechanical thrombectomy, and give a short review of the existing literature.

Updates on Prevention of Cardioembolic Strokes

Cardiac embolism continues to be a leading etiology of ischemic strokes worldwide. Although pathologies that result in cardioembolism have not changed over the past decade, there have been significant advances in the treatment and stroke prevention methods for these conditions. Atrial fibrillation remains the prototypical cause of cardioembolic strokes. The availability of new long-term monitoring devices for atrial fibrillation detection such as insertable cardiac monitors has allowed accurate detection of this leading cause of cardioembolism. The non-vitamin K antagonist oral anticoagulants have improved our ability to prevent strokes for many patients with non-valvular atrial fibrillation (NVAF). Advances in left atrial appendage closure and the U.S. Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device for stroke prevention in NVAF patients who have an appropriate rationale for a nonpharmacological alternative, have revolutionized the field and provided a viable option for patients at higher hemorrhagic risk. The role of patent foramen ovale closure for secondary prevention in selected patients experiencing cryptogenic ischemic strokes at a relatively young age has become clearer thanks to the very recent publication of long-term outcomes from three major studies. Advances in the management of infective endocarditis, heart failure, valvular diseases, and coronary artery disease have significantly changed the management of such patients, but have also revealed new concerns related to assessment of ischemic versus hemorrhagic risk in the setting of antithrombotic use. The current review article aims to discuss these advances especially as they pertain to the stroke neurology practice.