Embolization of the middle meningeal artery for the prevention of chronic subdural hematoma recurrence in high-risk patients: a randomized controlled trial-the EMPROTECT study protocol.

BACKGROUND: Middle meningeal artery (MMA) embolization has been proposed as a treatment of chronic subdural hematoma (CSDH). The benefit of the procedure has yet to be demonstrated in a randomized controlled trial. We aim to assess the efficacy of MMA embolization in reducing the risk of CSDH recurrence 6 months after burr-hole surgery compared with standard medical treatment in patients at high risk of postoperative recurrence. METHODS: The EMPROTECT trial is a multicenter open label randomized controlled trial (RCT) involving 12 French centers. Adult patients (≥18 years) operated for CSDH recurrence or for a first episode with a predefined recurrence risk factor are randomized 1:1 to receive either MMA embolization within 7 days of the burr-hole surgery (experimental group) or standard medical care (control group). The number of patients to be included is 342. RESULTS: The primary outcome is the rate of CSDH recurrence at 6 months. Secondary outcomes include the rate of repeated surgery for a homolateral CSDH recurrence during the 6-month follow-up period, the rate of disability and dependency at 1 and 6 months, defined by a modified Rankin Scale (mRS) score ≥4, mortality at 1 and 6 months, total cumulative duration of hospital stay during the 6-month follow-up period, directly or indirectly related to the CSDH and embolization procedure-related complication rates. CONCLUSIONS: The EMPROTECT trial is the first RCT evaluating the benefit of MMA embolization as a surgical adjunct for the prevention of CSDH recurrence. If positive, this trial will have a significant impact on patient care. TRIAL REGISTRATION NUMBER: NCT04372147.

Pituitary apoplexy score, toward standardized decision-making: a descriptive study.

Pituitary apoplexy (PA), a rare and life-threatening complication of pituitary adenomas, prompts urgent glucocorticoid administration. The optimal surgical approach is debated, and the Pituitary Apoplexy Score (PAS) aids decision-making. Our retrospective study (2003-2022) assesses variables in PA patient groups (surgical vs. non-surgical), applying PAS to establish a significant threshold for surgical decisions. Additionally, we aim to compare the rates of ophthalmological and endocrine deficit between both groups and identify any associated variables. PAS discrepancies were observed, with averages of 1.7 ± 1.7 (p < 0.0001) for conservative and 3.9 ± 1.7 (p < 0.0001) for surgical groups, confirmed by multivariate analysis (p = 0.009). A PAS threshold of 5, showing over 80% positive predictive value, was established. Patients with low prolactin levels (< 5 ng/ml) had higher corticotropic deficiency prevalence at 3-month and 1-year follow-ups (p = 0.017 and 0.027). Our study supports PAS as a valuable PA management tool, suggesting potential variable adjustments. Multicenter studies are crucial due to PA's low incidence.

Comparative analysis of histopathological parameters, genome-wide copy number alterations, and variants in genes involved in cell cycle regulation in chordomas of the skull base and sacrum.

Chordomas are rare tumors of the axial skeleton that are refractory to conventional therapy. Few studies have compared the morphological and molecular characteristics of chordomas according to the skull base and sacral locations. Histopathological data and changes revealed by array comparative genomic hybridization (CGH) and next-generation sequencing (NGS) of cell cycle regulation genes were analyzed for 28 skull base (SBCs) and 15 sacral (SC) chordomas. All cases were conventional chordomas. SBCs were significantly more frequent in patients aged <40 years and SCs predominated in patients aged >60 years. Mitotic indices ≥2 mitoses/10 high-power fields were correlated with high degrees of nuclear atypia and Ki67 labeling indices ≥6%. We identified 321 genomic positions, and copy number variation losses were more frequent than gain. Moreover, we report a panel of 85 genetic variants of cell cycle genes and the presence of molecular clusters for chordoma as well in CGH as in NGS. These new data strengthen the view that the chordoma should not be considered as a single molecular entity.

Treatment of A3.2 and A2 traumatic thoracolumbar spine compression fractures using vertebral body stenting: a 63-patient series.

BACKGROUND: Percutaneous treatments for spinal injury are underused by neuroradiologists and spine surgeons, mainly owing to a lack of data on indications. OBJECTIVE: To assess the safety and efficacy of vertebral body stenting (VBS) for post-traumatic A3.2 and A2 fractures (Magerl classification) and determine the factors that influence the improvements. METHODS: We retrospectively reviewed patients who underwent VBS to treat a single traumatic thoracolumbar fracture from 2010 to 2019. Kyphosis, loss of vertebral body height (VBH), and clinical and functional outcomes (including the Visual Analog Scale pain score and Oswestry Disability Index) were assessed. We examined the overall effects of VBH in all patients by constructing a linear statistical model and evaluated whether the efficacy was dependent on the characteristics of the patients or fractures. RESULTS: We included 63 patients comprising 44 A3.2 and 19 A2 fractures. No patient had worsening neurological symptoms or wound infection. The average rates of change were 67.1% (95% CI 59.1% to 75%) for kyphosis and 88.5% (95% CI 85.6% to 91.3%) for VBH (both p<0.0001). After 1 year, the VBS treatment was more effective for kyphosis in younger patients and at the L1 level, and for VBH in younger patients and cases of Magerl A3.2 fracture. CONCLUSIONS: This large reported series on VBS validates this surgical treatment. All patients had improved kyphosis and restored VBH. We recommend using VBS rather than open surgery for A3.2 and A2 fractures at the thoracolumbar junction and in young patients.

Extended endoscopic transsphenoidal approach for suprasellar craniopharyngiomas.

BACKGROUND: Craniopharyngiomas are benign sellar lesions. Surgical excision of craniopharyngiomas is difficult because of the surrounding important neurovascular structures. The choice of surgery depends on the histological type, location, hormonal status, and size of the craniopharyngioma, surrounding neurovascular structures, and invasion of the brain parenchyma. METHODS: We describe the resection of an adamantinomatous craniopharyngioma using an extended endoscopic endonasal approach and discuss the relevant surgical anatomy, indications, limitations, and possible complications. CONCLUSIONS: The extended endoscopic endonasal approach allows successful removal of the craniopharyngioma and poses little risk to surrounding neurovascular structures.

Treatment of congenital thrombocytopenia and decreased collagen reactivity in G6b-B-deficient mice.

Mice lacking the immunoreceptor tyrosine-based inhibition motif-containing co-inhibitory receptor G6b-B (Mpig6b, G6b knockout, KO) are born with a complex megakaryocyte (MK) per platelet phenotype, characterized by severe macrothrombocytopenia, expansion of the MK population, and focal myelofibrosis in the bone marrow and spleen. Platelets are almost completely devoid of the glycoprotein VI (GPVI)-FcRγ-chain collagen receptor complex, have reduced collagen integrin α2ß1, elevated Syk tyrosine kinase activity, and a subset has increased surface immunoglobulins. A similar phenotype was recently reported in patients with null and loss-of-function mutations in MPIG6B. To better understand the cause and treatment of this pathology, we used pharmacological- and genetic-based approaches to rescue platelet counts and function in G6b KO mice. Intravenous immunoglobulin resulted in a transient partial recovery of platelet counts, whereas immune deficiency did not affect platelet counts or receptor expression in G6b KO mice. Syk loss-of-function (R41A) rescued macrothrombocytopenia, GPVI and α2ß1 expression in G6b KO mice, whereas treatment with the Syk kinase inhibitor BI1002494 partially rescued platelet count but had no effect on GPVI and α2ß1 expression or bleeding. The Src family kinase inhibitor dasatinib was not beneficial in G6b KO mice. In contrast, treatment with the thrombopoietin mimetic romiplostim rescued thrombocytopenia, GPVI expression, and platelet reactivity to collagen, suggesting that it may be a promising therapeutic option for patients lacking functional G6b-B. Intriguingly, GPVI and α2ß1 expression were significantly downregulated in romiplostim-treated wild-type mice, whereas GPVI was upregulated in romiplostim-treated G6b KO mice, suggesting a cell intrinsic feedback mechanism that autoregulates platelet reactivity depending on physiological needs.

Megakaryocytes form linear podosomes devoid of digestive properties to remodel medullar matrix.

Bone marrow megakaryocytes (MKs) undergo a maturation involving contacts with the microenvironment before extending proplatelets through sinusoids to deliver platelets in the bloodstream. We demonstrated that MKs assemble linear F-actin-enriched podosomes on collagen I fibers. Microscopy analysis evidenced an inverse correlation between the number of dot-like versus linear podosomes over time. Confocal videomicroscopy confirmed that they derived from each-other. This dynamics was dependent on myosin IIA. Importantly, MKs progenitors expressed the Tks4/5 adaptors, displayed a strong gelatinolytic ability and did not form linear podosomes. While maturing, MKs lost Tks expression together with digestive ability. However, those MKs were still able to remodel the matrix by exerting traction on collagen I fibers through a collaboration between GPVI, ß1 integrin and linear podosomes. Our data demonstrated that a change in structure and composition of podosomes accounted for the shift of function during megakaryopoiesis. These data highlight the fact that members of the invadosome family could correspond to different maturation status of the same entity, to adapt to functional responses required by differentiation stages of the cell that bears them.

Platelet FcγRIIA-induced serotonin release exacerbates the severity of transfusion-related acute lung injury in mice.

Transfusion-related acute lung injury (TRALI) remains a major cause of transfusion-related fatalities. The mechanism of human antibody-mediated TRALI, especially the involvement of the Fcγ receptors, is not clearly established. Contrary to mice, human platelets are unique in their expression of the FcγRIIA/CD32A receptor, suggesting that our understanding of the pathogenesis of antibody-mediated TRALI is partial, as the current murine models incompletely recapitulate the human immunology. We evaluated the role of FcγRIIA/CD32A in TRALI using a humanized mouse model expressing the FcγRIIA/CD32A receptor. When challenged with a recombinant chimeric human immunoglobulin G1/mouse anti-major histocompatibility complex class I monoclonal antibody, these mice exhibited exacerbated alveolar edema and higher mortality compared with wild-type (WT) mice. Unlike in WT mice, monocytes/macrophages in CD32A+ mice were accessory for TRALI initiation, indicating the decisive contribution of another cell type. Platelet activation was dramatically increased in CD32A+ animals, resulting in their increased consumption and massive release of their granule contents. Platelet depletion prevented the exacerbation of TRALI in CD32A+ mice but did not affect TRALI in WT animals. By blocking platelet serotonin uptake with fluoxetine, we showed that the severity of TRALI in CD32A+ mice resulted from the serotonin released by the activated platelets. Furthermore, inhibition of 5-hydroxytryptamine 2A serotonin receptor with sarpogrelate, before or after the induction of TRALI, abolished the aggravation of lung edema in CD32A+ mice. Our findings show that platelet FcγRIIA/CD32A activation exacerbates antibody-mediated TRALI and provide a rationale for designing prophylactic and therapeutic strategies targeting the serotonin pathway to attenuate TRALI in patients.

Leukodepletion Filters-Derived CD34+ Cells As a Cell Source to Study Megakaryocyte Differentiation and Platelet Formation.

The in vitro expansion and differentiation of human hematopoietic progenitors into megakaryocytes capable of elongating proplatelets and releasing platelets allows an in-depth study of the mechanisms underlying platelet biogenesis. Available culture protocols are mostly based on hematopoietic progenitors derived from bone marrow or cord blood raising a number of ethical, technical, and economic concerns. If there are already available protocols for obtaining CD34 cells from peripheral blood, this manuscript proposes a straightforward and optimized protocol for obtaining CD34+ cells from leukodepletion filters readily available in blood centers. These cells are isolated from leukodepletion filters used in the preparation of blood transfusion products, corresponding to eight blood donations. These filters are meant to be discarded. A detailed procedure to collect hematopoietic progenitors identified as CD34+ cells from these filters is described. The method to obtain mature megakaryocytes extending proplatelets while discussing their phenotypic evolution is also detailed. Finally, the protocol present a calibrated pipetting method, to efficiently release platelets that are morphologically and functionally similar to native ones. This protocol can serve as a basis for evaluating pharmacological compounds acting at various steps of the process to dissect the underlying mechanisms and approach the in vivo platelet yields.