BACKGROUND: Right-side infective endocarditis (RSIE) is caused by microorganisms and develops into intracardiac and extracardiac complications with high in-hospital and 1-year mortality. Treatments involve antibiotic and surgical intervention. However, those presenting with extremes e.g. heart failure, or septic shock who are not ideal candidates for conventional medical therapy might benefit from minimally invasive procedures.
OBJECTIVE: This review summarizes existing observational studies that reported minimally invasive procedures to debulk vegetation due to infective endocarditis either on valve or cardiac implantable electronic devices.
METHODS: A targeted literature review was conducted to identify studies published in PubMed/MEDLINE, EMBASE, and Cochrane Central Database from January 1, 2015 to June 5, 2023. The efficacy and/or effectiveness of minimally invasive procedural interventions to debulk vegetation due to RSIE were summarized following PRISMA guidelines.
RESULTS: A total of 11 studies with 208 RSIE patients were included. There were 9 studies that assessed the effectiveness of the AngioVac system and 2 assessed the Penumbra system. Overall procedure success rate was 87.9%. Among 8 studies that reported index hospitalization, 4 studies reported no death, while the other 4 studies reported 10 deaths.
CONCLUSIONS: This study demonstrates that multiple systems can provide minimally invasive procedure options for patients with RSIE with high procedural success. However, there are mixed results regarding complications and mortality rates. Further large cohort studies or randomized clinical trials are warranted to assess and/or compare the efficacy and safety of these systems.

UNASSIGNED: Computed tomography perfusion (CTP) has successfully extended the time window for reperfusion therapies in ischemic stroke. However, the published perfusion parameters and thresholds vary between studies. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines, we conducted a systematic review to investigate the accuracy of parameters and thresholds for identifying core and penumbra in adult stroke patients.
UNASSIGNED: We searched Medline, Embase, the Cochrane Library, and reference lists of manuscripts up to April 2022 using the following terms \"computed tomography perfusion,\" \"stroke,\" \"infarct,\" and \"penumbra.\" Studies were included if they reported perfusion thresholds and undertook co-registration of CTP to reference standards. The quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool and Standards for Reporting of Diagnostic Accuracy (STARD) guidelines.
UNASSIGNED: A total of 24 studies were included. A meta-analysis could not be performed due to insufficient data and significant heterogeneity in the study design. When reported, the mean age was 70.2 years (SD+/-3.69), and the median NIHSS on admission was 15 (IQR 13-17). The perfusion parameter identified for the core was relative cerebral blood flow (rCBF), with a median threshold of <30% (IQR 30, 40%). However, later studies reported lower thresholds in the early time window with rapid reperfusion (median 25%, IQR 20, 30%). A total of 15 studies defined a single threshold for all brain regions irrespective of collaterals and the gray and white matter.
UNASSIGNED: A single threshold and parameter may not always accurately differentiate penumbra from core and oligemia. Further refinement of parameters is needed in the current era of reperfusion therapy.

Stroke is the second most common cause of death worldwide, with 50% of survivors experiencing long-term disability. For more than two decades, treatment with intravenous thrombolysis (IVT) and mechanical endovascular thrombectomy (MET), the only approved stroke reperfusion therapies, was restricted to patients within the 4.5-6 hour time window, respectively. Therefore, patients who presented with acute ischemic stroke (AIS) beyond the conventional time window were excluded from reperfusion treatment. This narrative review aims to review the scientific literature on the possibilities of reperfusion therapies for patients who present with an unknown time of stroke onset, and those with stroke onset beyond the conventional 4.5-6 hour time window. Beyond the conventional time window, the eligibility of patients for IVT or MET, the two main therapeutic procedures, is decided based on the concept of penumbral imaging. Penumbral imaging identifies patients with hypoperfused but viable brain tissue, who could benefit from reperfusion. On the other hand, clock-based DWI-fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can detect stroke that has occurred within 4.5 hours in patients with an unknown time of onset, including patients who awaken with stroke. The introduction of penumbral imaging and MRI-based tissue clocking as imaging biomarkers for stroke has revolutionized stroke therapy, potentially allowing for personalized treatment of eligible stroke patients.

Ischemic stroke is characterized by a complex cascade of events starting from vessel occlusion. The term \"penumbra\" denotes the area of severely hypo-perfused brain tissue surrounding the ischemic core that can be potentially recovered if blood flow is reestablished. From the neurophysiological perspective, there are local alterations-reflecting the loss of function of the core and the penumbra-and widespread changes in neural networks functioning, since structural and functional connectivity is disrupted. These dynamic changes are closely related to blood flow in the affected area. However, the pathological process of stroke does not end after the acute phase, but it determines a long-term cascade of events, including changes of cortical excitability, that are quite precocious and might precede clinical evolution. Neurophysiological tools-such as Transcranial Magnetic Stimulation (TMS) or Electroencephalography (EEG)-have enough time resolution to efficiently reflect the pathological changes occurring after stroke. Even if they do not have a role in acute stroke management, EEG and TMS might be helpful for monitoring ischemia evolution-also in the sub-acute and chronic stages. The present review aims to describe the changes occurring in the infarcted area after stroke from the neurophysiological perspective, starting from the acute to the chronic phase.

While the time window for reperfusion after ischemic stroke continues to increase, many patients are not candidates for reperfusion under current guidelines that allow for reperfusion within 24 h after last known well time; however, many case studies report favorable outcomes beyond 24 h after symptom onset for both spontaneous and medically induced recanalization. Furthermore, modern imaging allows for identification of penumbra at extended time points, and reperfusion risk factors and complications are becoming better understood. Taken together, continued urgency exists to better understand the pathophysiologic mechanisms and ideal setting of delayed recanalization beyond 24 h after onset of ischemia.

Periodic lateralized epileptiform discharges (PLEDs) or lateralized periodic discharges (LPDs) are a well-known variant of pathological EEG activity. However, the mechanisms underpinning the appearance of this pattern are not completely understood. The heterogeneity of the features derived from LPDs patterns, and the wide range of pathological conditions in which they occur, raise a question about the unifying mechanisms underlying these phenomena. This paper reassesses the current opinion surrounding LPDs which considers glutamate excitotoxicity to be the primary pathophysiological basis, and the penumbral region to be the main morphological substrate. Arguments in favour of this hypothesis are presented, with interpretations supported by evidence from recent literature involving clinical and experimental data. Presently, no single hypothesis places considerable emphasis on the pathochemical properties of LPDs, which are implicitly meaningful towards better understanding of the clinical significance of this pattern.

Acute ischemic strokes account for 85% of all strokes and are the fifth leading cause of mortality in the United States. About one in five of all ischemic strokes occur during sleep and are not noticed until the patient wakes up with neurological deficits. There is growing evidence to support that a significantly higher number of stroke patients could benefit from more aggressive care, especially those patients who wake up with strokes. There is increasing research to support a physiologically-based approach based on advanced imaging rather than simply a time-based determination of whether or not a patient would benefit from reperfusion. Advanced imaging such as CT-Perfusion and MR DWI-FLAIR can be used to establish the age of the lesion and determine the extent of the brain tissue that is salvageable. If physicians could identify those patients with wake-up strokes that are candidates for intervention, there may be opportunity to treat 3 million more people, reducing long term disability and healthcare expenditures. Patients who are in the window for IV rtPA should receive it as soon as possible as well as be evaluated for mechanical thrombectomy. For those who are out of the window for IV rtPA, consider further imaging such as CTP and MR brain for diffusion-weighted sequences to evaluate for potential endovascular intervention. If a large vessel occlusion is present and imaging demonstrates a small infarct core and a large area of salvageable tissue, mechanical thrombectomy may be beneficial for the best possible functional outcome.

Acute renal artery embolism (RAE) is a rare condition associated with significant morbidity and mortality. The treatment strategy for RAE includes anticoagulation with or without thrombolysis or surgical or endovascular embolectomy. We describe here a case presentation of acute RAE secondary to atrial fibrillation treated successfully with Penumbra Indigo Aspiration System, a novel device in peripheral endovascular interventions. Our patient had ongoing symptoms and acute renal failure on presentation with contraindication to thrombolysis given hypertensive emergency. A 6F Penumbra Aspiration catheter was used to aspirate large amounts of thrombus from segmental renal arteries with restoration of flow. Patient\'s symptoms and renal function returned to baseline after intervention. Penumbra system is used routinely in cerebral endovascular intervention, yet here we describe its potential use in peripheral vascular interventions in addition to a literature review of all available evidence for the different treatment modalities of acute RAE.