Revascularisation patterns and characteristics after erythropoietin pretreatment and multiple burr holes in patients who had acute stroke with perfusion impairment.

BACKGROUND: Transdural collaterals, originating mainly from the extracalvarial superficial temporal artery and intracalvarial middle meningeal artery via the external carotid artery (ECA), have been observed after revascularisation surgery. However, the origin of these collaterals in patients with stroke with perfusion insufficiency is not yet known. Therefore, we studied the revascularisation patterns and characteristics based on the origin of these collaterals. METHODS: We employed erythropoietin pretreatment and performed multiple burr holes under local anaesthesia to achieve transdural revascularisation in patients with acute stroke with perfusion insufficiency. After 6 months, we reassessed the transfemoral cerebral angiography to evaluate the revascularisation patterns. The collaterals were categorised into intracalvarial ECA-dominant (originating from the middle meningeal artery), extracalvarial ECA-dominant (originating from the superficial temporal or occipital artery) and balanced groups. We compared various imaging parameters among these groups. RESULTS: Overall, 87 patients with 103 treated hemispheres were involved. Among them, 57.3% were classified as intracalvarial ECA-dominant, 20.4% as extracalvarial ECA-dominant and 22.3% as balanced. Most of the hemispheres with intracalvarial or extracalvarial collaterals (vs balanced collaterals) showed successful revascularisation (78/80 (97.5%) vs 12/23 (52.1%)), p<0.001). In ultrasonographic haemodynamic changes according to revascularisation pattern, only the intracalvarial ECA-dominant revascularisation was significantly associated with specific changes in ECA blood flow, leading to the conversion to a low-resistance ECA Doppler sonography waveform. CONCLUSIONS: Our findings suggest that intracalvarial ECA-dominant revascularisation plays a crucial role in the formation of transdural collaterals following combined therapy. These distinct changes in ECA haemodynamics can be non-invasively identified through bedside ultrasound studies.

RNF213 variant and autophagic impairment: A pivotal link to endothelial dysfunction in moyamoya disease.

Moyamoya disease (MMD) is closely associated with the Ring Finger Protein 213 (RNF213), a susceptibility gene for MMD. However, its biological function remains unclear. We aimed to elucidate the role of RNF213 in the damage incurred by human endothelial cells under oxygen-glucose deprivation (OGD). We analyzed autophagy in peripheral blood mononuclear cells (PBMCs) derived from patients carrying either RNF213 wildtype (WT) or variant (p.R4810K). Subsequently, human umbilical vein endothelial cells (HUVECs) were transfected with RNF213 WT (HUVECWT) or p.R4810K (HUVECR4810K) and exposed to OGD for 2 h. Immunoblotting was used to analyze autophagy marker proteins, and endothelial function was analyzed by tube formation assay. Autophagic vesicles were observed using transmission electron microscopy. Post-OGD exposure, we administered rapamycin and cilostazol as potential autophagy inducers. The RNF213 variant group during post-OGD exposure (vs. pre-OGD) showed autophagy inhibition, increased protein expression of SQSTM1/p62 (p < 0.0001) and LC3-II (p = 0.0039), and impaired endothelial function (p = 0.0252). HUVECR4810K during post-OGD exposure (versus pre-OGD) showed a remarkable increase in autophagic vesicles. Administration of rapamycin and cilostazol notably restored the function of HUVECR4810K and autophagy. Our findings support the pivotal role of autophagy impaired by the RNF213 variant in MMD-induced endothelial cell dysfunction.

Transdural Revascularization by Multiple Burrhole After Erythropoietin in Stroke Patients With Cerebral Hypoperfusion: A Randomized Controlled Trial.

BACKGROUND: In patients with acute symptomatic stroke, reinforcement of transdural angiogenesis using multiple burr hole (MBH) procedures after EPO (erythropoietin) treatment has rarely been addressed. We aimed to investigate the efficacy and safety of cranial MBH procedures under local anesthesia for augmenting transdural revascularization after EPO treatment in patients with stroke with perfusion impairments. METHODS: This prospective, randomized, blinded-end point trial recruited patients with acute ischemic stroke with a perfusion impairment of grade ≥2 within 14 days of symptom onset, steno-occlusive mechanisms on imaging examinations, and absence of transdural collaterals on transfemoral cerebral angiography. Patients were randomly assigned to receive MBH + EPO or MBH alone. The primary and secondary outcomes were revascularization success (trans-hemispheric and trans-burr hole) at 6 months and adverse events, respectively. RESULTS: We evaluated 42 of the 44 targeted patients, with 2 patients lost to follow-up. The combined and MBH-only (n=21 each) groups showed no differences in demographic characteristics and baseline perfusion parameters. Significantly, more cases of trans-hemispheric (19/21 [90.5%] versus 12/21 [57.1%]) and trans-burr hole (42/58 [72.4%] versus 30/58 [51.7%]) revascularization and significant improvements in perfusion parameters were observed in the combined group relative to the MBH-only group. No differences in treatment-related complications were observed between groups. Even after adjustment for potential covariates, EPO usage was an independent factor of successful hemispheric revascularization in this study (odds ratio, 6.41 [95% CI, 1.08-38.02]). CONCLUSIONS: The combination of MBH and EPO is safe and feasible for reinforcing transdural revascularization in acute steno-occlusive patients with perfusion impairments. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02603406.

A novel global ischemia-reperfusion rat model with asymmetric brain damage simulating post-cardiac arrest brain injury.

BACKGROUND: Post-cardiac arrest brain injury (PCABI) is a major cause of disability and death in patients with post-cardiac arrest syndrome (PCAS). However, there have been no suitable animal models with characteristic behaviors and cerebral damage adequately mimicking clinical PCABI. NEW METHOD: We established a chimeric model by increasing transient middle cerebral artery occlusion-mediated ipsilateral hemisphere damage in the 4-vessel occlusion (4VO) model, thereby inducing global forebrain asymmetric hemisphere ischemia. Severity of brain damage was then evaluated by behavioral and histological approaches. Neuroprotection was assessed by performing targeted temperature management (TTM) for two hours. RESULTS: Comatose behaviors were observed in both groups. Compared to the 4VO group, the chimeric group exhibited a higher neurological deficit score (NDS) (70.5 ± 17.6 vs. 139.5 ± 16.8, p = 0.0002), decreased brain cell viability (88.6 ± 18.0% vs. 5.7 ± 2.7%, p < 0.0001), and increased inflammation in the cortex (10.3 ± 1.6% vs. 16.9 ± 1.1%, p = 0.0061). After TTM neuroprotection, the chimeric-TTM group showed improvement in NDS (139.5 ± 16.8 vs. 0.0 ± 0.0, p < 0.0001), cortex and hippocampus cell viability (5.7 ± 2.7% vs. 72.8 ± 10.0%, p < 0.0001; and 2.5 ± 1.5% vs. 75.5 ± 10.3%, p < 0.0001, respectively) and inflammation (16.9 ± 1.1% vs. 11.0 ± 2.3%, p = 0.190; and 30.9 ± 1.7% vs. 16.6 ± 1.2%, p < 0.0001, respectively) compared to the chimeric group. COMPARISON WITH EXISTING METHOD: Unlike the extensive brain damage found in clinical PCAS settings, the existing 4VO models showed only global forebrain damage involving CA1 lesions on both hippocampi. Our model induced global forebrain and additional asymmetric hemisphere ischemic damages, which resulted in simulating PCABI-specific clinical manifestations than conventional models. CONCLUSIONS: Our model adequately simulates clinical PCABI and reflects appropriate neuroprotective effects of TTM.

Cranial burr hole with erythropoietin administration induces reverse arteriogenesis from the enriched extracranium.

It is challenging to revitalize ischemic penumbra after an acute stroke with intracranial perfusion insufficiency. To evaluate whether cranial burr hole and erythropoietin (EPO) generate effective revascularization, we investigated the efficacy of the augmentation method for reverse arteriogenesis from the healthy extracranial milieu. An intracranial perfusion insufficiency was created through bilateral internal carotid artery ligation (bICAL) in Sprague-Dawley rats. We administered recombinant human EPO (5000 U/kg) or saline intraperitoneally for 3 days after bICAL. Mechanical barrier disruption (MBD) was performed through a cranial burr hole with small dural cracks in the right hemisphere. The ipsilateral hemisphere with MBD grossly showed vascular networks between the extra- and intra-cranial spaces 2 weeks after the MBD procedure. It also showed significantly increased vessels in the intracranial vasculature adjacent to the MBD region (p = 0.0006). The levels of pro-angiogenic and inflammatory factors with prominent markers of vessel permeability were also significantly increased (MBD-only vs. control; Tnf-α, p = 0.0007; Vegf, p = 0.0206). In the EPO-administered group, such elevations in inflammation were significantly mitigated (combined vs. MBD-only; Tnf-α, p = 0.0008). The ipsilateral hemisphere with MBD-EPO (vs. MBD-only) showed significantly increased vessels (RECA-1, p = 0.0182) and their maturation (RECA-1/α-SMA, p = 0.0046), with upregulation of tumor growth factor-ß1 (Tgf-ß1, p = 0.037) and matrix metalloproteinase-2 (Mmp-2, p = 0.0488). These findings were completely blocked by minocycline (MIC) administration during in vivo (Tgf-ß1, p = 0.0009; Mmp-2, p < 0.0001) and in vitro experiments (tube formation, p < 0.0001). Our data suggest that the MBD procedure (for angiogenic routes) and EPO administration (for an arteriogenic booster) are complimentary and can facilitate successfully "reverse arteriogenesis" in subjects with intracranial perfusion insufficiency.

Erythrocyte Fraction Within Retrieved Thrombi Contributes to Thrombolytic Response in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Recent advent of endovascular thrombectomy (EVT) enables us to provide a new perspective on the use of tPA (tissue-type plasminogen activator) through histological analysis of retrieved thrombus. We investigated the responsiveness of intravenous thrombolysis (IVT) according to the thrombus composition in EVT-attempted patients with acute ischemic stroke. METHODS: We reviewed 92 consecutive patients with anterior circulation stroke who received combined IVT and EVT for 2 years. IVT responsiveness is defined as any decrease in the clot burden from baseline computed tomographic angiography to digital subtraction angiography during EVT. We histologically analyzed the relative fractions of red blood cells (RBCs), congregated fibrin and platelets, and white blood cells in the retrieved thrombi using semiautomated color-based segmentation method. Clinical characteristics according to the RBC fraction were investigated, and associated factors with IVT responsiveness were explored. RESULTS: Fifty-two patients with histological analyses were stratified into lowest, middle, and highest tertiles of RBC fraction. Toward higher RBC fraction, there was more common susceptibility vessel signs on magnetic resonance imaging (50.0% versus 66.7% versus 91.7%; P=0.022) and prevalent IVT responsiveness (25.0% versus 41.7% versus 75.0%; P=0.010). IVT-responsive group (n=23) had higher RBC fraction (45.7±15.5% versus 35.9±12.2%; P=0.010), lower fibrin and platelet (50.4±14.0% versus 58.5±11.1%; P=0.027), and lower white blood cells fraction (3.9±2.1% versus 5.5±3.0%; P=0.027) than IVT-unresponsive group (n=29). After adjusting for potential variables, RBC fraction (odds ratio, 1.05; 95% confidence interval, 1.01-1.10) remained only independent determinant of IVT responsiveness. CONCLUSIONS: In EVT-attempted patients with acute ischemic stroke, IVT responsiveness would be closely associated with RBC fraction.