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

LPS induces RGS-1 to promote infectious intracranial aneurysm formation and rupture by accelerating smooth muscle cell phenotypic switching

OBJECTIVE

Patients with infectious intracranial aneurysms (IIAs) have high mortality rates. Sepsis is an important condition that induces IIA. Smooth muscle cell (SMC) phenotypic switching may have a critical effect on sepsis-induced IIA, but its role remains unclear. Hence, we aimed to identify sepsis-induced target genes involved in SMC phenotypic switching and their underlying mechanisms.

METHODS AND RESULTS

RNA sequencing and bioinformatics analyses of samples from patients with intracranial aneurysms and sepsis identified RGS-1 as a common differentially expressed gene (DEG) involved in SMC phenotypic switching. Experimental verification demonstrated that lipopolysaccharide (LPS), a critical molecule in sepsis, increased RGS-1 levels, promoted SMC phenotypic switching and proliferation, and upregulated the expression of matrix metalloproteinases and inflammatory factors. Furthermore, qRT-PCR and immunofluorescence experiments confirmed that RGS-1 knockdown under LPS stimulation inhibited SMC phenotypic switching, cell proliferation, and decreases in matrix metalloproteinases and inflammatory factors. Mechanistically, western blotting, bioinformatics analyses, and chip assays revealed that RGS-1 activates the JNK-P38 pathway to promote SMC phenotypic switching and is regulated by the transcription factor STAT1.

CONCLUSION

LPS induces RGS-1 to promote IIA formation and rupture by accelerating SMC phenotypic switching.

Significant increase in mortality and risk of acute ischemic stroke in infective endocarditis patients with subarachnoid hemorrhage secondary to mycotic aneurysms

Infective Endocarditis (IE) patients are known to have a variety of complications with one of the rarest, but serious being cerebral mycotic aneurysm, which can result in subarachnoid hemorrhage (SAH). Using the National In-Patient Sample database, we sought to determine the rate of acute ischemic stroke (AIS) and outcomes in IE- patients with and without SAH. In total, we identified 82,844 IE-patients from 2010 to 2016, of which 641 had a concurrent diagnosis of SAH. IE patients with SAH had a more complicated course, higher mortality rate (OR 4.65 CI 95% 3.9-5.5, P < 0.001), and worse outcomes. This patient population also had a significantly higher rate of AIS (OR 6.3 CI 95% 5.4-7.4, P < 0.001). Overall, 41.5% of IE-patients with SAH had AIS during their hospitalization as compared to 10.1% of IE only patients. IE-patients with SAH were more likely to undergo endovascular treatment (3.6%) with 0.8% of the IE patients with AIS undergoing mechanical thrombectomy. While IE-patients are at risk for various complications, our study suggests a significant increase in the mortality and risk of AIS in those with SAH.

Endovascular treatment of an infectious aneurysm using the selective provocative test and transcranial motor evoked potential monitoring under general anesthesia: a case report

The selective provocative test (SPT) under local anesthesia aids in protecting against ischemic complications during endovascular treatment. However, the use of this test under general anesthesia is not well described. Herein, we present a case of a 51-year-old man with a ruptured fusiform aneurysm in the middle cerebral artery M4 segment, which was thought to possibly supply the motor cortex. Internal trapping of the affected vessel and aneurysm by endovascular intervention was successfully performed after SPT using transcranial motor evoked potential (MEP) monitoring under general anesthesia. Transcranial MEP is suitable for neurological assessment during SPT under general anesthesia.

Endovascular treatment of infectious intracranial aneurysms complicating infective endocarditis: a series of 31 patients with 55 aneurysms

PURPOSE

Endovascular treatment (EVT) has become a major option in management of infectious intracranial aneurysms (IIAs) complicating infective endocarditis. We report a retrospective, single-center series of consecutive patients with IIAs treated by EVT.

METHODS

Patients were included from January 2009 to July 2020. IIAs were diagnosed on DSA. Each patient underwent a neurological assessment before and after EVT and was followed up by imaging within 15 days of EVT. Safety was assessed on the evolution of NIHSS score. A minor stroke was defined as a worsening of NIHSS < 4 points. Efficacy was defined as the absence of hemorrhagic event during cardiac surgery and the exclusion of the IIA on control imaging.

RESULTS

Sixty-two IIAs (30 ruptured) were diagnosed in 31 patients. Fifty-six IIAs were diagnosed on the first DSA and 6 on the early control exploration. EVT was achieved in 55 IIAs by parent artery occlusion with glue in 52 distal IIAs and coils in 3 proximal IIAs. IIAs were located in 90.9% of cases on a fourth-division branch of a cerebral artery. The neurological examination remained unchanged in 29 patients (93.5%), and 2 patients suffered minor stroke. EVT was performed before cardiac surgery in 20/22 patients. All treated IIAs were excluded on follow-up imaging. No hemorrhage was observed during cardiac surgery or in the aftermath. Seven (11.3%) unruptured IIAs were not embolized.

CONCLUSION

EVT of IIAs by occlusion of the parent artery is effective in preventing rupture and carries no significant neurological risk.

Rapid formation and rupture of an infectious basilar artery aneurysm from meningitis following suprasellar region meningioma removal: a case report

Background

Infectious basilar artery (BA) aneurysm has been occasionally reported to be generated from meningitis following transcranial operation. However, infectious BA aneurysm formed by intracranial infection after endoscopic endonasal operation has never been reported.

Case presentation

A 53-year-old man who was diagnosed with suprasellar region meningioma received tumor removal via endoscopic endonasal approach. After operation he developed cerebrospinal fluid (CSF) leak and intracranial infection. The patient ultimately recovered from infection after anti-infective therapy, but a large fusiform BA aneurysm was still formed and ruptured in a short time. Interventional and surgical measures were impossible due to the complicated shape and location of aneurysm and state of his endangerment, therefore, conservative anti-infective therapy was adopted as the only feasible method. Unfortunately, the aneurysm did not disappear and the patient finally died from repeating subarachnoid hemorrhage (SAH).

Conclusion

Though extremely rare, it was emphasized that infectious aneurysm can be formed at any stage after transnasal surgery, even when the meningitis is cured. Because of the treatment difficulty and poor prognosis, it was recommended that thorough examination should be timely performed for suspicious patient to make correct diagnosis and avoid fatal SAH.

Provocative Testing Prior to Anterior Cerebral Artery Fusiform Aneurysm Embolization

We report 2 cases of parent artery occlusion (PAO) for anterior cerebral artery (ACA) fusiform aneurysm embolization after superselective provocative testing was performed to confirm distal territory viability. The first case involves a patient in the second decade of life who presented with subarachnoid hemorrhage and underwent PAO after a balloon test occlusion in the distal ACA revealed no neurophysiology changes. The second case involves another patient in the forth decade of life who presented with an enlarging pseudoaneurysm and underwent PAO after a sodium amobarbital infusion in the distal ACA revealed no clinical change. Both patients tolerated PAO without clinical compromise. PAO after provocative testing may be a safe and effective strategy in the management of fusiform aneurysm treatment.

Key Messages

Provocative testing with superselective balloon test occlusion and sodium amobarbital infusion are both viable options for clinical and physiological interrogation of brain tissue prior to parent vessel occlusion. Neurophysiological monitoring may be a useful surrogate for clinical examination after provocative testing, particularly if patients were treated under general anesthesia.

Infectious intracranial aneurysms: a systematic review of epidemiology, management, and outcomes

Infectious intracranial aneurysms (IIAs) are a rare cerebrovascular complication of systemic infections induced by microbial infiltration and degradation of the arterial vessel wall. Studies on the epidemiology and management of IIAs are limited to case reports and retrospective single-center studies, and report a large variability in epidemiological features, management, and outcomes due to the limited sample size. We conducted a systematic review of all published papers on IIAs in the English literature using MEDLINE and SCOPUS database from January 1950 to June 2017. A total of 288 publications describing 1191 patients with IIA (1398 aneurysms) were included and reviewed for epidemiological features, disease features, treatment and outcome. All patients were merged into a single cohort and summary data are presented. The majority of reported IIAs are distally located, relatively small (<5 mm), involve the anterior circulation, are associated with a relatively high rate of rupture, and demonstrate a propensity to multiplicity of aneurysms. Sensitive diagnosis of IIAs requires digital subtraction angiography and not CT angiography or MR angiography. Treatment of ruptured, symptomatic, or enlarging IIAs has evolved over the last 50 years. Endovascular therapy is associated with a high success rate and low morbidity compared with microsurgical and medical management. A treatment algorithm for the management of patients with IIA in various contexts is proposed and the need for prospective multicenter studies is emphasized.