Intracranial infectious aneurysms: a comprehensive review

Management of Septic emboli in patients with infectious endocarditis

BACKGROUND AND AIM

Septic emboli (SE) associated with infectious endocarditis (IE) can result in splenic abscesses and infectious intracranial aneurysms (IIA). We investigated the impact of SE on patient outcomes following surgery for IE.

METHOD

From January-2000 to October-2015, all patients with surgical IE (n = 437) were evaluated for incidence and management of SE.

RESULTS

Overall SE was found in 46/437 (10.52%) patients (n = 17 spleen, 13 brain, and 16 both). No mortality was seen in the brain emboli groups, but in the splenic abscess group the in-hospital mortality was 8.69% (n = 4); and was associated with Age >35 (OR = 2.63, 1.65-4.20) and congestive heart failure (OR = 14.40, 1.23-168.50). Patients with splenic emboli had excellent mid-term outcome following discharge (100% survival at 4-years). Splenic emboli requiring splenectomy was predicted by a >20 mm valve vegetation (OR = 1.37, 1.056-1.77) and WBC >12000 cells/mm (OR = 5.58, 1.2-26.3). No patient with streptococcus-viridians infection had a nonviable spleen (OR = 0.67, 0.53-0.85). Postoperative acute-kidney-injury was higher in the splenectomy group (45.45% vs 9%) (p = 0.027). There were 6 patients with symptomatic IIAs that required coiling/clipping which was associated with age <30 years, (OR = 6.09, 1.10-33.55). Survival in patients with cerebral emboli decreased to 78% at 3-4 years. Patients with both splenic and brain emboli had a 92% survival rate at 1-year and 77% at 2-4 years.

CONCLUSION

Septic emboli is common in endocarditis patients. Patients with high preoperative WBC level and large valve vegetations require CT imaging of the spleen. Both spleen and brain interventions in the setting of IE can be performed safely with excellent early and mid-term outcomes.

Endovascular Treatment of Intracavernous Internal Carotid Aneurysm Secondary to Pituitary Infection

BACKGROUND

Intracavernous internal carotid artery (ICICA) aneurysm secondary to pituitary infection is exceedingly rare.

CASE DESCRIPTION

We report an unusual case of a 63-year-old man who presented with acute left blepharoptosis and imaging findings of a pituitary infection. Interestingly, sudden onset of right blepharoptosis occurred after anti-infective therapy for 10 days. Digital subtraction angiography revealed a right ICICA aneurysm. After 6 months of follow-up visits, enlargement of the ICICA aneurysm was observed, and the endovascular technique of a low-profile visualized intraluminal support stent combined with 5 detachable coils was successfully performed to treat the ICICA aneurysm, with preservation of the internal carotid artery.

CONCLUSION

This rare case highlights a life-threatening complication of a pituitary infection. Moreover, enlargement of the infected ICICA aneurysm could not be relieved by conservative anti-infective therapy. Endovascular treatment may be an alternative therapy for an infected ICICA aneurysm.

Endovascular Embolization of Intracranial Infectious Aneurysms in Patients Undergoing Open Heart Surgery Using n-Butyl Cyanoacrylate

INTRODUCTION

Mycotic aneurysms are a serious complication of infective endocarditis with increased risk of intracranial hemorrhage. Patients undergoing open heart surgery for valve repair or replacement are exposed to anticoagulants, increasing the risk of aneurysm bleeding. These patients may require endovascular or surgical aneurysm treatment prior to heart surgery, but data on this approach are scarce.

METHODS

Retrospective review of consecutive patients with infectious endocarditis and mycotic aneurysms treated endovascularly with Trufill n-butyl cyanoacrylate (n-BCA) at the Cleveland Clinic between January 2013 and December 2015.

RESULTS

Nine patients underwent endovascular treatment of mycotic aneurysms with n-BCA (mean age of 39 years). On imaging, 4 patients had intracerebral hemorrhage, 2 had multiple embolic infarcts, and the rest had no imaging findings. Twelve mycotic aneurysms were detected (3 patients with 2 aneurysms). Seven aneurysms were in the M4 middle cerebral artery segment, 4 in the posterior cerebral artery distribution, and 1 in the callosomarginal branch. n-BCA was diluted in ethiodized oil (1:1 to 1:2). Embolization was achieved in a single rapid injection with immediate microcatheter removal. Complete aneurysm exclusion was achieved in all cases without complications. All patients underwent open heart surgery and endovascular embolization within a short interval, 2 with both procedures on the same day. There were no new hemorrhages after aneurysm embolization.

CONCLUSIONS

Endovascular embolization of infectious intracranial aneurysms with liquid embolics can be performed successfully in critically ill patients requiring immediate open heart surgery and anticoagulation. Early embolization prior to and within a short interval from open heart surgery is feasible.

Interdisciplinary Treatment of Intracranial Infectious Aneurysms

OBJECTIVE

Intracranial infectious aneurysms (IIAs) are a rare clinical entity without a definitive treatment guideline. In this study, we evaluate the treatment options of these lesions based on our own clinical experience and review the current knowledge of therapy as portrayed in the literature.

METHODS

We conducted a single-center retrospective analysis of all patients with an IIA and performed a systematic review of the literature using the MEDLINE database. We undertook a comprehensive literature search using the OVID gateway of the MEDLINE database (1950-October 2015) using the following keywords (in combination): 'infectious', 'mycotic', 'cerebral aneurysm', 'intracranial aneurysm'. 1,721 potentially relevant abstracts were identified and 63 studies were selected for full review. The studies were analysed regarding ruptured versus unruptured aneurysms, aneurysm localization and treatment, as well as clinical and radiological outcome.

RESULTS

Our institutional series consisted of 6 patients (median age 57 [32-76]) treated between 2011 and 2015. All patients presented with ruptured IIAs located on the middle cerebral artery (MCA, 5 patients) and anterior cerebral artery (ACA, 1 patient). Five patients were treated by clipping and resecting the aneurysm, 1 patient underwent coiling. All patients received antibiotic therapy and 1 patient died. We further identified 814 patients (median age 35.5 [0-81]) in 63 studies. Locations of the aneurysms were mentioned in 55 studies. The most frequent locations of the aneurysms were: MCA (63.5%), posterior cerebral artery (14%), ACA (9.0%) and others (13.5%). Treatment for IIAs was described in 62 studies: antibiotic treatment (56.1%), a combination of antibiotics and surgery (20.9%) or antibiotics and endovascular treatment (23.0%). Outcome was mentioned in 82.4% of the patients with a mortality rate of 16.8%. An evaluation of treatment outcome was limited due to the heterogeneity of patients in the published case series.

CONCLUSION

Antibiotic therapy of patients with IIA is mandatory. However, due to the complexity of the disease and its accompanying comorbidities, a general treatment algorithm could not be defined. Analogous to non-mycotic aneurysms, further treatment decisions require an interdisciplinary approach involving neurosurgeons, interventionists and infectious disease specialists.

Management of infectious intracranial aneurysms in the pediatric population

INTRODUCTION

Infectious intracranial aneurysms (IIAs) account for approximately 15 % of all pediatric intracranial aneurysms. Histologically, they are pseudoaneurysms that develop in response to an inflammatory reaction within the adventitia and muscularis layers, ultimately resulting in disruption of both the internal elastic membrane and the intima. The majority of pediatric IIAs are located within the anterior circulation, and they can be multiple in 15-25 % of cases.

BACKGROUND

The most common presentation for an IIA is intracerebral and/or subarachnoid hemorrhage. In children with a known diagnosis of infective endocarditis who develop new neurological manifestations, it is imperative to exclude the existence of an IIA. The natural history of untreated infectious aneurysms is ominous; they demonstrate a high incidence of spontaneous rupture. High clinical suspicion, prompt diagnosis, and adequate treatment are of paramount importance to prevent devastating neurological consequences.

DISCUSSION

The prompt initiation of intravenous broad-spectrum antibiotics represents the mainstay of treatment. Three questions should guide the management of pediatric patients with IIAs: (a) aneurysm rupture status, (b) the presence of intraparenchymal hemorrhage or elevated intracranial pressure, and (c) relationship of the parent vessel to eloquent brain tissue. Those three questions should orient the treating physician into either antibiotic therapy alone or in combination with microsurgical or endovascular interventions. This review discusses important aspects of the epidemiology, the diagnosis, and the management of IIAs in the pediatric population.

Infective Endocarditis Presenting with Intracranial Bleeding

BACKGROUND

Infective endocarditis (IE) can be complicated by intracranial bleeding (ICB) caused by different pathologic mechanisms. The occurrence of ICB in patients with IE significantly influences therapeutic decisions and has a negative impact on outcome.

CASE REPORT

We describe the clinical courses of 3 patients with aortic prosthetic valve IE presenting with ICB. Patients 1 and 2 experienced subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH), respectively, caused by rupture of an intracranial infectious aneurysm (IIA). Both underwent endovascular treatment of IIA with good outcome. In patient 3, ICB was the hemorrhagic conversion of an acute ischemic lesion from septic brain embolization. In the subacute phase of the disease, aortic valve replacement was performed, with excellent outcome. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ICB is a relevant complication and sometimes the first clinical feature of IE. Imaging of brain vessels should be performed to investigate the pathologic mechanism underlying ICB. The prevalence of IIA is probably underestimated and may influence the therapeutic strategy. Cerebrovascular imaging may therefore also be considered in asymptomatic subjects with left-sided IE. Withdrawal of anticoagulant treatment and delay of cardiac surgery are recommended in all cases of IE complicated by ICB. Because of the impact of ICB on IE management and outcome, a high level of clinical suspicion and prompt recognition and treatment of this complication are necessary.

A case of ruptured infectious anterior cerebral artery aneurysm treated by interposition graft bypass using the superficial temporal artery

Background:

To describe the application of an interposition graft bypass using superficial temporal artery (STA) for the treatment of a ruptured anterior cerebral artery (ACA) infectious aneurysm.

Case Description:

A 30-year-old male suffered from severe headache with high fever. The patient's diagnosis was ruptured infectious ACA aneurysm at the A3 segment with a maximum diameter of 4.5 mm, caused by infectious endocarditis. The patient was initially treated with high-dose intravenous antibiotics. Follow-up digital subtraction angiography (DSA) revealed that the fusiform aneurysm had enlarged to a maximum diameter of 14.0 mm. A left paracentral artery, supplying the motor area of the left lower extremity, originated from the body of this aneurysm. Because the angiographic findings suggested a risk of recurrent bleeding, the patient underwent open surgery. Interposition graft bypass using the STA was performed to reconstruct the left A3 segment in an end-to-side manner (left proximal callosomarginal artery – STA graft – left distal pericallosal artery). Then, the origin of the left paracentral artery was cut and anastomosed to the STA graft in an end-to-side manner. The affected parent artery was trapped, and the aneurysm was resected. Postoperative magnetic resonance imaging showed no ischemic or hemorrhagic complications, and postoperative DSA revealed the patency of the interposition graft. Pathological diagnosis of the resected aneurysm revealed features corresponding to infectious cerebral aneurysm. The postoperative course was uneventful, and the patient was discharged without any neurological deficits.

Conclusion:

In the treatment of infectious cerebral aneurysms, revascularization should be considered when the affected artery supplies the eloquent area. Interposition graft bypass using the STA is one of the options for revascularization surgery for the treatment of infectious ACA aneurysms.

Bacterial DNA findings in ruptured and unruptured intracranial aneurysms

OBJECTIVE

Chronic inflammation has earlier been detected in ruptured intracranial aneurysms. A previous study detected both dental bacterial DNA and bacterial-driven inflammation in ruptured intracranial aneurysm walls. The aim of this study was to compare the presence of oral and pharyngeal bacterial DNA in ruptured and unruptured intracranial aneurysms. The hypothesis was that oral bacterial DNA findings would be more common and the amount of bacterial DNA would be higher in ruptured aneurysm walls than in unruptured aneurysm walls.

MATERIALS AND METHODS

A total of 70 ruptured (n = 42) and unruptured (n = 28) intracranial aneurysm specimens were obtained perioperatively in aneurysm clipping operations. Aneurysmal sac tissue was analysed using a real-time quantitative polymerase chain reaction to detect bacterial DNA from several oral species. Both histologically non-atherosclerotic healthy vessel wall obtained from cardiac by-pass operations (LITA) and arterial blood samples obtained from each aneurysm patient were used as control samples.

RESULTS

Bacterial DNA was detected in 49/70 (70%) of the specimens. A total of 29/42 (69%) of the ruptured and 20/28 (71%) of the unruptured aneurysm samples contained bacterial DNA of oral origin. Both ruptured and unruptured aneurysm tissue samples contained significantly more bacterial DNA than the LITA control samples (p-values 0.003 and 0.001, respectively). There was no significant difference in the amount of bacterial DNA between the ruptured and unruptured samples.

CONCLUSION

Dental bacterial DNA can be found using a quantitative polymerase chain reaction in both ruptured and unruptured aneurysm walls, suggesting that bacterial DNA plays a role in the pathogenesis of cerebral aneurysms in general, rather than only in ruptured aneurysms.

True mycotic aneurysm in a patient with gonadotropinoma after trans-sphenoidal surgery

Background:

Immunosuppressive therapy, prolonged antibiotic use, and intrathecal injections are known risk factors for the development of invasive aspergillosis. Central nervous system (CNS) aspergillosis can manifest in many forms, including mycotic aneurysm formation. The majority of the mycotic aneurysms presents with subarachnoid hemorrhage after rupture and are associated with high mortality. Only 3 cases of true mycotic aneurysms have been reported following trans-sphenoidal surgery.

Case Description:

A 38-year-old man was admitted with nonfunctioning pituitary adenoma for which he underwent trans-sphenoidal surgery. Three weeks later, he presented with cerebrospinal fluid (CSF) rhinorrhea and meningitis. He was treated with intrathecal and intravenous antibiotics, stress dose of glucocorticoids, and lumbar drain. The defect in the sphenoid bone was closed endoscopically. After 3 weeks of therapy, he suddenly became unresponsive, and computed tomography of the head showed subarachnoid hemorrhage. He succumbed to illness on the next day, and a limited autopsy of the brain was performed. The autopsy revealed extensive subarachnoid hemorrhage and aneurysmal dilatation, thrombosis of the basilar artery (BA), multiple hemorrhagic infarcts in the midbrain, and pons. Histopathology of the BA revealed the loss of internal elastic lamina and septate hyphae with an acute angle branching on Grocott's methenamine silver stain, conforming to the morphology of Aspergillus.

Conclusion:

The possibility of intracranial fungal infection should be strongly considered in any patient receiving intrathecal antibiotics who fails to improve in 1–2 weeks, and frequent CSF culture for fungi should be performed to confirm the diagnosis. Since CSF culture has poor sensitivity in the diagnosis of fungal infections of CNS; empirical institution of antifungal therapy may be considered in this scenario.

Fungal Mycotic Aneurysm of the Internal Carotid Artery Associated with Sphenoid Sinusitis in an Immunocompromised Patient: A Case Report and Review of the Literature

In immunocompromised patients, invasive molds such as Aspergillus and Mucor can lead to locally aggressive angioinvasive infections that are often life-threatening. A particularly devastating complication is the development of a fungal mycotic aneurysm resulting from invasion of the arterial wall. Due to anatomic contiguity, the sphenoid sinus provides potential access for these fungi, which often colonize the respiratory sinuses, into the cavernous sinus and internal carotid artery (ICA), thus leading to the formation of ICA aneurysms. The ideal treatment of fungal ICA aneurysms includes a combination of surgical debridement and long-term effective antifungal therapy, but the role of endoscopic resection and the duration of antimicrobials are poorly defined. Here, we present the case of a 71-year-old immunocompromised patient who developed an ICA mycotic aneurysm, associated with a proven invasive fungal infection (presumptively Mucorales) of the sphenoid sinuses, as defined by EORTC/MSG criteria, and who survived after undergoing coil embolization with parent vessel sacrifice of the aneurysm in combination with liposomal amphotericin B. We also review the literature for published cases of invasive fungal sphenoid sinusitis associated with mycotic aneurysms of the ICA and provide a comparative analysis .

Endovascular treatment of intracranial infectious aneurysms in eloquent cortex with super-selective provocative testing: Case series and literature review

Intracranial infectious aneurysms (IIAs) are a rare subgroup of intracranial aneurysms. Often erroneously termed mycotic aneurysms, these lesions most often result from infectious endocarditis and involve the distal anterior cortical circulation. Diagnosis typically follows headaches or septic infarcts, although increasing numbers of lesions are found incidentally, during screening protocols for infectious endocarditis. Open surgical treatment was previously the mainstay of treatment; however, these IIAs are often fusiform and quite fragile, making open surgical obliteration difficult and typically requiring lesion trapping. Current treatment techniques more commonly involve endovascular coil embolization or parent vessel occlusion. Many of these lesions occur distally, in or around the eloquent cortex, making embolization potentially dangerous. We present cases that highlight the use of super-selective provocative testing with sodium amobarbital and lidocaine, to help clarify and predict the risk of parent vessel occlusion in IIAs located in the eloquent cortex.

National treatment practices in the management of infectious intracranial aneurysms and infective endocarditis

Introduction

There is an absence of widely accepted guidelines for the management of infectious intracranial aneurysms (IIAs) owing to a dearth of high-quality evidence in the literature.

Objective

To better define the incidence of IIAs, treatment practices, and patient outcomes by performing a Nationwide Inpatient Sample (NIS) database query.

Methods

We queried the NIS database from 2002 to 2011 for all patients with theprimary diagnosisof infectious endocarditis (IE), subarachnoid hemorrhage (SAH), or unruptured cerebral aneurysm by ICD-9-CM codes. ICD-9 procedure codes were used to identify patients undergoing neurosurgical or cardiothoracic procedures.

Results

The query identified 393 patients withprimary diagnosisof IE, SAH or unruptured cerebral aneurysm treated during 2002–2011. The mean age of the patients was 53.5 years; 244 (62%) were male. The majority of patients presented with SAH (361; 91.9%). Only 73 (18.6%) patients underwent neurosurgical coiling or clipping for IIA. Of patients undergoing a neurosurgical procedure, 65 had SAH (constituting only 18% of patients with SAH) and 8 had unruptured aneurysms (constituting only 25% patients with unruptured aneurysms). Cardiac procedures were performed in only 72/393 patients (18.3%) patients. Only 67 (18.6%) of the patients with SAH and 5 (15.6%) with unruptured aneurysms underwent a cardiac corrective surgical procedure. Mortality was significantly higher in those patients managed conservatively (26.7%) than in those who underwent clipping or embolization (15.1%; p<0.001).

Conclusions

In this NIS database study, the majority of patients with IIAs were managed non-operatively, regardless of rupture status. Further investigation is warranted to standardize the management of these lesions.

Preoperative Cerebrovascular Evaluation in Patients With Infective Endocarditis

Approximately 12% to 40% of infective endocarditis patients experience cerebrovascular complications. One of the major clinical challenges in cerebrovascular medicine is management of infective endocarditis patients with cerebrovascular complications who require valve operations. Cerebrovascular specialists are often summoned to address appropriate preoperative brain imaging, timing of surgery, and estimation of the risk of perioperative cerebral embolization and hemorrhage. This article addresses these issues based on the available evidence.

The imaging features of neurologic complications of left atrial myxomas

BACKGROUND

Neurologic complications may be the first symptoms of atrial myxomas. Understanding the imaging features of neurologic complications of atrial myxomas can be helpful for the prompt diagnosis.

OBJECTIVE

To identify neuroimaging features for patients with neurologic complications attributed to atrial myxoma.

METHODS

We retrospectively reviewed the medical records of 103 patients with pathologically confirmed atrial myxoma at Xiangya Hospital from January 2009 to January 2014. The neuroimaging data for patients with neurologic complications were analyzed.

RESULTS

Eight patients with atrial myxomas (7.77%) presented with neurologic manifestations, which constituted the initial symptoms for seven patients (87.5%). Neuroimaging showed five cases of cerebral infarctions and three cases of aneurysms. The main patterns of the infarctions were multiplicity (100.0%) and involvement of the middle cerebral artery territory (80.0%). The aneurysms were fusiform in shape, multiple in number (100.0%) and located in the distal middle cerebral artery (100.0%). More specifically, high-density in the vicinity of the aneurysms was observed on CT for two patients (66.7%), and homogenous enhancement surrounding the aneurysms was detected in the enhanced imaging for two patients (66.7%).

CONCLUSION

Neurologic complications secondary to atrial myxoma consist of cerebral infarctions and aneurysms, which show certain characteristic features in neuroimaging. Echocardiography should be performed in patients with multiple cerebral infarctions, and multiple aneurysms, especially when aneurysms are distal in location. More importantly, greater attention should be paid to the imaging changes surrounding the aneurysms when myxomatous aneurysms are suspected and these are going to be the relevant features in our article.

Results and current trends of multimodality treatment for infectious intracranial aneurysms

The authors retrospectively reviewed their cases of infectious intracranial aneurysms and discuss results and trends of current treatment modalities including medical, neurosurgical, and endovascular. Twenty patients (10 males and 10 females; mean age 46 years) with 23 infectious aneurysms were treated by various treatment modalities during a 15-year period. Fifteen cases (75.0%) were caused by infective endocarditis. Eleven aneurysms (47.8%) were ruptured. Two aneurysms (8.7%) presented a mass effect and 7 (30.4%) were unruptured and asymptomatic. The average aneurysm size was 6.5 ± 4.8 mm (range 1–22 mm). The aneurysms were located in proximal cerebral circulation in 7 (30.4%) and distal in 16 (69.6%). Six (26.1%) aneurysms were treated surgically (5: trapping, 1: neck clipping), 10 (43.5%) endovascularly (7: trapping, 2: proximal occlusion, 1: saccular coiling), and the remaining 7 (30.4%) medically. Endovascular treatment was gradually increased with time. Medical and surgical treatments were continuously performed during the study period. Surgery was preferred for the patient with intraparenchymal hematoma or treated by bypass surgery. Three periprocedural minor complications occurred in endovascular treatment. There was one postoperative infarction with permanent deficit developed from surgical treatment. During the follow-up period (mean 28.8 months), none of the aneurysms presented a recurrence or rebleeding. Thirteen patients (65.0%) had favorable clinical outcomes (modified Rankin Scale: 0–2), although four (20.0%) had poor outcomes (modified Rankin Score: 5–6). A multimodal approach for the management of infectious aneurysms achieved satisfactory results. Endovascular intervention is a feasible and efficacious treatment option and surgical intervention is still an indispensable procedure.

Intracranial mycotic aneurysm associated with left ventricular assist device infection

Infection is a frequent complication of left ventricular assist device (LVAD) use in patients with severe heart failure. The development of bacteremia with "LVAD endocarditis" is a serious infection that has rarely been associated with mycotic aneurysm formation. We describe the first case of an LVAD-associated intracranial mycotic aneurysm. We suggest that this is an underappreciated condition that merits more aggressive evaluation and treatment in patients with chronic LVAD-associated infections.

Enterococcal endocarditis complicated with ruptured infected-intracranial aneurysm: with pharmacokinetic-pharmacodynamic documentation in proof of the successful antimicrobial treatment

A 74-year-old man presented with sudden onset of aphasia and apraxia. Magnetic resonance image (MRI) of the brain disclosed a left frontal hemorrhage. The concomitant low grade fever suggestive of infection was unresponsive to cefazolin 1 g q12h, and refractory to piperacillin (PIPC) 2 g q8h. Blood culture grew enterococci, establishing together with echocardiography the diagnosis of infective endocarditis. The angiography revealed cerebral hemorrhage to have resulted from the rupture of the infected intracranial aneurysm. The antimicrobial therapy was switched to ampicillin (ABPC) 2 g q4h plus gentamicin (GM) 60 mg q8h. The positive blood culture was subsequently identified Enterococcus faecium to which the minimum inhibitory concentration (MIC) of PIPC, and ABPC was 16 mcg/mL, and 4 mcg/mL, respectively. The peak concentration of serum ABPC was 83.1, median 50.8, and trough 25.8 mcg/mL. Thus, the percent time > MIC for ABPC was 100%, and the time > minimum bactericidal concentration (MBC) as well. On the other hand, time > MIC for PIPC, was found nearly 30% in retrospective analysis using population pharmacokinetics. The neurological deficit of the patient was completely restored to the normal status after 4-weeks' antimicrobial therapy with ABPC plus GM, then he underwent cardiac surgery for valvular replacement, where microbiological culture of the resected valve was negative. The constellation of the clinical, pharmacological and microbiological outcome in our case provides scientific evidence that the antibiotic therapy given to our case is the best available strategy as an antimicrobial treatment of severe enterococcal endocarditis complicated by disseminated lesion as infected intracranial aneurysm.

Unreported neurological complications of Gemella bergeriae infective endocarditis

We report the first case of native aortic and mitral valve endocarditis due to Gemella bergeriae from the Middle East in a young patient with rheumatic heart disease. Our case illustrates a fulminant course of infection with G. bergeriae endocarditis that was complicated by embolic stroke, as well as intracerebral and subarachnoid haemorrhage secondary to rupture of a mycotic aneurysm in the right middle cerebral artery. This case highlights the dire, unreported neurological complications of infective endocarditis due to a rare causative organism-G. bergeriae.

Meningitis complicated by mycotic aneurysms

Mycotic aneurysms complicated by vasospasm and strokes represent a rare manifestation of bacterial meningitis. We describe a healthy woman diagnosed with bacterial meningitis and mycotic aneurysms, who received both antibiotic and corticosteroid therapy. This approach fostered a significant radiologic improvement in her mycotic aneurysms as evidenced by serial angiographic examinations. During her course, she developed vasospasm and strokes and required intra-arterial verapamil. More importantly and as a result of these combined therapies, the patient experienced a substantial clinical improvement. This case allows the description of mycotic aneurysms epidemiology, clinical presentation and complications. In addition, our vignette bestows the relevance of serial neurologic examinations and radiologic testing during the acute vasculopathy period. Current conservative and interventional therapeutic options are briefly discussed.

Mycotic aneurysm detection rates with cerebral angiography in patients with infective endocarditis

BACKGROUND

Cerebral angiography remains the gold standard for the detection of mycotic aneurysms, and it has been estimated that ruptured mycotic aneurysms result in 5% of the neurological complications of patients with infective endocarditis (IE).

OBJECTIVE

To determine the diagnostic yield of cerebral angiography in the above patient population and to assess patient factors that might suggest greater or lesser utility.

METHODS

We retrospectively reviewed 168 patients who underwent cerebral angiography with a diagnosis of IE or infected left ventricular assist device at the Cleveland Clinic between January 2003 and March 2010 in accordance with institutional review board guidelines. Chart and imaging review was performed.

RESULTS

15/168 patients (8.9%) had mycotic aneurysms; 93.3% (14/15) of the patients with mycotic aneurysms presented with CNS hemorrhage and 66.7% (10/15) had acute ischemic findings. Of the 15 patients with mycotic aneurysms on angiography, seven underwent CT angiography and six underwent MR angiography, which showed mycotic aneurysms in three (42.9%) and two cases (one of which was questionable; 33.3%), respectively.

CONCLUSIONS

Patients with IE or similar sources of central bacterial emboli are prone to neurovascular complications. Approximately 9% of patients with IE at our institution who undergo cerebral angiography have mycotic aneurysms. Presentation with hemorrhage appears to be more predictive of aneurysm, as approximately 22% of patients with IE and hemorrhage were found to have an aneurysm compared with only 1% when hemorrhage was absent. Thus, patients with IE presenting with intracranial hemorrhage should undergo vascular imaging, preferably with cerebral angiography.

Patient selection for endovascular treatment of intracranial aneurysms

With recent advancement in medical imaging, techniques, and endovascular tools more patients are diagnosed with unruptured intracranial aneurysms. The main aim of offering aneurysm treatment is to ameliorate the risk of future aneurysm bleeding, while not posing additional risks on the patient from the treatment itself. We discuss in this paper our approach of selecting patients for treatment (simple coiling, balloon-assisted, stent-assisted, vessel sacrifice, or flow-divertion stents). Our decision-making is based on the published data and our center experience. Risks of all option are compared to each other and weighed against natural history of intracranial aneurysms. In this paper, literature is cited and case illustrations are presented to support this approach. Factors that affect our decision-making are aneurysm location, presentation, size, aneurysm geometry, parent vessel anatomy, and relevant co-morbidities.

Symptomatic peripheral mycotic aneurysms due to infective endocarditis: a contemporary profile

Peripheral mycotic aneurysms (PMAs) are a relatively rare but serious complication of infective endocarditis (IE). We conducted the current study to describe and compare the current epidemiologic, microbiologic, clinical, diagnostic, therapeutic, and prognostic characteristics of patients with symptomatic PMAs (SPMAs). A descriptive, comparative, retrospective observational study was performed in 3 tertiary hospitals, which are reference centers for cardiac surgery. From 922 definite IE episodes collected from 1996 to 2011, 18 patients (1.9%) had SPMAs. Because all SPMAs developed in left-sided IE, we performed a comparative study between 719 episodes of left-sided IE without SPMAs and 18 episodes with SPMAs. We found a higher frequency of intravenous drug abuse, native valve IE, intracranial bleeding, septic emboli, multiple embolisms, and IE diagnostic delay >30 days in patients with SPMAs than in patients without SPMAs. The causal microorganisms were gram-positive cocci (n =10), gram-negative bacilli (n = 2), gram-positive bacilli (n = 3), Bartonella henselae (n = 1), Candida albicans (n = 1), and negative culture (n = 1). The median IE diagnosis delay was 15 days (interquartile range [IQR], 13-33 d) in the case of high-virulence microorganisms versus 45 days (IQR, 30-240 d) in the case of low- to medium-virulence microorganisms. Twelve SPMAs were intracranial and 6 were extracranial. In 10 cases (8 intracranial and 2 extracranial), SPMAs were the initial presentation of IE; the remaining cases developed symptoms during or after finishing parenteral antibiotic treatment. The initial diagnosis of intracranial SPMAs was made by computed tomography (CT) or magnetic resonance imaging in 6 unruptured aneurysms and by angiography in 6 ruptured aneurysms. The initial test in extracranial SPMAs was Doppler ultrasonography in limbs, CT in liver, and coronary angiography in heart. Four (3 intracranial, 1 extracranial) of 7 (6 intracranial, 1 extracranial) patients treated only with antibiotics died. Surgical resection was performed in 7 (3 intracranial, 4 extracranial) and endovascular repair in 4 (3 intracranial, 1 extracranial) patients; all of them survived. In conclusion, we found that SPMAs were a rare complication of IE that developed only in left-sided IE, and especially in native valves. Intracranial hemorrhage, embolism, multiple embolisms, and diagnostic delay of IE were more common in patients with SPMAs. The microbiologic profile was diverse, but microorganisms of low-medium virulence were predominant, and had a greater delayed diagnosis of IE than those caused by microorganisms of high virulence. SPMAs were often the initial presentation of IE. The most common location of SPMAs was intracranial. Noninvasive radiologic imaging techniques were the initial imaging test in intracranial unruptured SPMAs and in most extracranial SPMAs. Surgical and endovascular treatments were safe and effective. Endovascular treatment could be the first line of treatment in selected cases. Mortality was high in those cases treated only with antibiotics.

Infective endocarditis

Infective endocarditis is a serious disease of the endocardium of the heart and cardiac valves, caused by a variety of infectious agents, ranging from streptococci to rickettsia. The proportion of cases associated with rheumatic valvulopathy and dental surgery has decreased in recent years, while endocarditis associated with intravenous drug abuse, prosthetic valves, degenerative valve disease, implanted cardiac devices, and iatrogenic or nosocomial infections has emerged. Endocarditis causes constitutional, cardiac and multiorgan symptoms and signs. The central nervous system can be affected in the form of meningitis, cerebritis, encephalopathy, seizures, brain abscess, ischemic embolic stroke, mycotic aneurysm, and subarachnoid or intracerebral hemorrhage. Stroke in endocarditis is an ominous prognostic sign. Treatment of endocarditis includes prolonged appropriate antimicrobial therapy and in selected cases, cardiac surgery. In ischemic stroke associated with infective endocarditis there is no indication to start antithrombotic drugs. In previously anticoagulated patients with an ischemic stroke, oral anticoagulants should be replaced by unfractionated heparin, while in intracranial hemorrhage, all anticoagulation should be interrupted. The majority of unruptured mycotic aneurysms can be treated by antibiotics, but for ruptured aneurysms, endovascular or neurosurgical therapy is indicated.

Neurologic complications of valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications; cerebral embolism is the most common of these since thrombus formation results from the abnormalities in the valvular surfaces or from the anatomic and physiologic changes associated with valve dysfunction, such as atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for anticoagulation for the prevention of embolism. Infective endocarditis is a disease process with protean manifestations that include not only cerebral embolism but also intracranial hemorrhage, mycotic aneurysms, and systemic manifestations such as fever and encephalopathy. Other neurologic complications include nonbacterial thrombotic endocarditis, a process associated with systemic diseases such as cancer and systemic lupus erythematosus. For many of these conditions, anticoagulation is the mainstay of treatment to prevent cerebral embolism, therefore it is the potential complications of anticoagulation that can explain other neurologic complications in patients with VHD. The prevention and management of these complications requires an understanding of their natural history in order to balance the risks posed by valvular disease itself against the risks and benefits associated with treatment.

Endovascular treatment of cerebral mycotic aneurysm: a review of the literature and single center experience

The management of mycotic aneurysm has always been subject to controversy. The aim of this paper is to review the literature on the intracranial infected aneurysm from pathogenesis till management while focusing mainly on the endovascular interventions. This novel solution seems to provide additional benefits and long-term favorable outcomes.

Neurological complications of infective endocarditis: new breakthroughs in diagnosis and management

Neurological complications are frequent in infective endocarditis (IE) and increase morbidity and mortality rates. A wide spectrum of neurological disorders may be observed, including stroke or transient ischemic attack, cerebral hemorrhage, mycotic aneurysm, meningitis, cerebral abscess, or encephalopathy. Most complications occur early during the course of IE and are a hallmark of left-sided abnormalities of native or prosthetic valves. Ischemic lesions account for 40% to 50% of IE central nervous system complications. Systematic brain MRI may reveal cerebral abnormalities in up to 80% of patients, including cerebral embolism in 50%, mostly asymptomatic. Neurological complications affect both medical and surgical treatment and should be managed by an experimented multidisciplinary team including cardiologists, neurologists, intensive care specialists, and cardiac surgeons. Oral anticoagulant therapy given to patients presenting with cerebral ischemic lesions should be replaced by unfractionated heparin for at least 2 weeks, with a close monitoring of coagulation tests. Recently published data suggest that after an ischemic stroke, surgery indicated for heart failure, uncontrolled infection, abscess, or persisting high emboli risk should not be delayed, provided that the patient is not comatose or has no severe deficit. Surgery should be postponed for 2 to 3 weeks for patients with intracranial hemorrhage. Endovascular treatment is recommended for cerebral mycotic aneurysms, if there is no severe mass effect. Recent data suggests that neurological failure, which is associated with the location and extension of brain injury, is a major determinant for short-term prognosis.

Ruptured mycotic cerebral aneurysm development from pseudoocclusion due to septic embolism

Background:

Cerebral mycotic aneurysms are rare sequelae of systemic infections that can cause profound morbidity and mortality with rupture. Direct bacterial extension and vessel integrity compromise from septic emboli have been implicated as mechanisms for formation of these lesions. We report the 5-day development of a ruptured mycotic aneurysm arising from a septic embolism that caused a focal M1 pseudoocclusion.

Case Description:

A 14-year-old girl developed acute left-sided hemiparesis while hospitalized for subacute bacterial endocarditis that was found after she presented with a 2-week history of fever, myalgia, shortness of breath, and lethargy. Mitral valve vegetations were confirmed in the setting of hemophilus bacteremia. Brain magnetic resonance (MR) imaging and angiography confirmed middle cerebral artery infarct with focal pseudoocclusion of the distal M1 segment. Given that further middle cerebral artery territory was at risk, a trial of heparin was attempted for revascularization but required discontinuation owing to hemorrhagic conversion. Decline of the patient's mental status necessitated craniectomy for decompression. Postoperatively, her mental status improved with residual left hemiparesis. On the third postoperative day (5 days after MR angiography), the patient's neurologic condition acutely declined, with development of right-sided mydriasis. Computed tomography (CT) angiography revealed a ruptured 19 × 16 mm pseudoaneurysm arising from the M1 site of the previous occlusion. Emergent coiling of aneurysm and parent vessel followed by hematoma evacuation ensued. At discharge, the patient had residual left hemiparesis but intact speech and cognition.

Conclusion:

Focal occlusions due to septic emboli should be considered high-risk for mycotic aneurysm formation, prompting aggressive monitoring with neuroimaging and treatment when indicated.

The connection between ruptured cerebral aneurysms and odontogenic bacteria

BACKGROUND

Patients with ruptured saccular intracranial aneurysms have excess long-term mortality due to cerebrovascular and cardiovascular diseases compared with general population. Chronic inflammation is detected in ruptured intracranial aneurysms, abdominal aortic aneurysms and coronary artery plaques. Bacterial infections have been suggested to have a role in the aetiology of atherosclerosis. Bacteria have been detected both in abdominal and coronary arteries but their presence in intracranial aneurysms has not yet been properly studied.

OBJECTIVE

The aim of this preliminary study was to assess the presence of oral and pharyngeal bacterial genome in ruptured intracranial aneurysms and to ascertain if dental infection is a previously unknown risk factor for subarachnoid haemorrhage.

METHODS

A total of 36 ruptured aneurysm specimens were obtained perioperatively in aneurysm clipping operations (n=29) and by autopsy (n=7). Aneurysmal sac tissue was analysed by real time quantitative PCR with specific primers and probes to detect bacterial DNA from several oral species. Immunohistochemical staining for bacterial receptors (CD14 and toll-like receptor-2 (TLR-2)) was performed from four autopsy cases.

RESULTS

Bacterial DNA was detected in 21/36 (58%) of specimens. A third of the positive samples contained DNA from both endodontic and periodontal bacteria. DNA from endodontic bacteria were detected in 20/36 (56%) and from periodontal bacteria in 17/36 (47%) of samples. Bacterial DNA of the Streptococcus mitis group was found to be most common. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Treponema denticola were the three most common periodontal pathogens. The highly intensive staining of CD14 and TLR-2 in ruptured aneurysms was observed.

CONCLUSIONS

This is the first report showing evidence that dental infection could be a part of pathophysiology in intracranial aneurysm disease.

Ruptured mycotic aneurysm of the distal middle cerebral artery manifesting as subacute subdural hematoma

Mycotic aneurysms are rare inflammatory neurovascular lesions. Ruptured mycotic aneurysm manifesting as subdural hematoma is extremely rare. A 72-year-old male patient was admitted to our hospital with headache and drowsiness. Computer tomography (CT) of brain and CT angiography revealed subdural hematoma and an aneurysm located at the M4 segment of the left middle cerebral artery (MCA). Cerebral angiogram revealed 2 aneurysms; one located at the left distal MCA and the other at the bifurcation of left MCA. Laboratory studies showed leukocytosis and elevated inflammatory factors. The patent was treated with antibiotic therapy for 4 weeks. The follow-up CT and cerebral angiography showed that the mycotic aneurysm was completely resolved, and the patient was nearly free of symptoms.