Paediatric intracranial dural arteriovenous fistulas: clinical characteristics, treatment outcomes and prognosis.

BACKGROUND: Compared with dural arteriovenous fistulas (DAVFs) in adult, paediatric DAVFs are notable for distinct clinical manifestations, low cure rate and poor prognosis. However, due to the limitations of small sample sizes, the long-term prognosis and follow-up data have not been described. METHODS: Clinical data from 43 consecutive paediatric DAVFs were documented and analysed between 2002 and 2022 at the author's institution. They were divided into infantile (Lasjaunias classification) and non-infantile (adult type and dural sinus malformation (DSM)) type DAVFs based on prognosis differences. RESULTS: Their mean age at first symptoms was 8.4±6.0 years. 29 boys and 14 girls presented between at birth and 18 years of age. 5 of 10 patients ≤1 year of age presented with asymptomatic cardiomegaly compared with 5/33 patients >1 year of age (p=0.022). 42 (88.4%) patients received endovascular treatment alone, while 9.3% underwent radiosurgery, burr hole embolisation or surgery. 28 (65.1%) patients experienced DAVF obliteration by the end of treatment. Among them, 26 cases underwent embolisation alone, one case had embolisation in conjunction with surgery, and one case underwent burr hole embolisation. The overall complication rate among patients was 9.3%, all resulting from endovascular treatment. According to the Lasjaunias Classification, there were 18 cases of adult type, 17 cases of infantile type and 8 cases of DSM. Compared with non-infantile-type DAVFs, infantile-type DAVFs showed more times of treatment, lower cure rate and worse prognosis (p<0.001, 0.003 and 0.021, respectively). The average follow-up duration was 41.4±36.2 months (3-228 months). 8 (22.9%) patients died. CONCLUSIONS: Most adult-type DAVFs and DSMs can now be effectively treated with embolisation, resulting in good outcomes and prognosis. However, there are still challenges in treating infantile-type DAVFs, and the prognosis is frequently poor.

Somatic BrafV600E mutation in the cerebral endothelium induces brain arteriovenous malformations.

Current treatments of brain arteriovenous malformation (BAVM) are associated with considerable risks and at times incomplete efficacy. Therefore, a clinically consistent animal model of BAVM is urgently needed to investigate its underlying biological mechanisms and develop innovative treatment strategies. Notably, existing mouse models have limited utility due to heterogenous and untypical phenotypes of AVM lesions. Here we developed a novel mouse model of sporadic BAVM that is consistent with clinical manifestations in humans. Mice with BrafV600E mutations in brain ECs developed BAVM closely resembled that of human lesions. This strategy successfully induced BAVMs in mice across different age groups and within various brain regions. Pathological features of BAVM were primarily dilated blood vessels with reduced vascular wall stability, accompanied by spontaneous hemorrhage and neuroinflammation. Single-cell sequencing revealed differentially expressed genes that were related to the cytoskeleton, cell motility, and intercellular junctions. Early administration of Dabrafenib was found to be effective in slowing the progression of BAVMs; however, its efficacy in treating established BAVM lesions remained uncertain. Taken together, our proposed approach successfully induced BAVM that closely resembled human BAVM lesions in mice, rendering the model suitable for investigating the pathogenesis of BAVM and assessing potential therapeutic strategies.

The subcommissural organ regulates brain development via secreted peptides.

The subcommissural organ (SCO) is a gland located at the entrance of the aqueduct of Sylvius in the brain. It exists in species as distantly related as amphioxus and humans, but its function is largely unknown. Here, to explore its function, we compared transcriptomes of SCO and non-SCO brain regions and found three genes, Sspo, Car3 and Spdef, that are highly expressed in the SCO. Mouse strains expressing Cre recombinase from endogenous promoter/enhancer elements of these genes were used to genetically ablate SCO cells during embryonic development, resulting in severe hydrocephalus and defects in neuronal migration and development of neuronal axons and dendrites. Unbiased peptidomic analysis revealed enrichment of three SCO-derived peptides, namely, thymosin beta 4, thymosin beta 10 and NP24, and their reintroduction into SCO-ablated brain ventricles substantially rescued developmental defects. Together, these data identify a critical role for the SCO in brain development.

Identification of pathogen composition in a Chinese population with iatrogenic and native vertebral osteomyelitis by using mNGS.

BACKGROUND: Early antimicrobial therapy is crucial regarding the prognosis of vertebral osteomyelitis, but early pathogen diagnosis remains challenging. OBJECTIVE: In this study, we aimed to differentiate the types of pathogens in iatrogenic vertebral osteomyelitis (IVO) and native vertebral osteomyelitis (NVO) to guide early antibiotic treatment. METHODS: A total of 145 patients, who had confirmed spinal infection and underwent metagenomic next-generation sequencing (mNGS) testing, were included, with 114 in the NVO group and 31 in the IVO group. Using mNGS, we detected and classified 53 pathogens in the 31 patients in the IVO group and 169 pathogens in the 114 patients in the NVO group. To further distinguish IVO from NVO, we employed machine learning algorithms to select serum biomarkers and developed a nomogram model. RESULTS: The results revealed that the proportion of the Actinobacteria phylum in the NVO group was approximately 28.40%, which was significantly higher than the 15.09% in the IVO group. Conversely, the proportion of the Firmicutes phylum (39.62%) in the IVO group was markedly increased compared to the 21.30% in the NVO group. Further genus-level classification demonstrated that Staphylococcus was the most common pathogen in the IVO group, whereas Mycobacterium was predominant in the NVO group. Through LASSO regression and random forest algorithms, we identified 5 serum biomarkers including percentage of basophils (BASO%), percentage of monocytes (Mono%), platelet volume (PCT), globulin (G), activated partial thromboplastin time (APTT) for distinguishing IVO from NVO. Based on these biomarkers, we established a nomogram model capable of accurately discriminating between the two conditions. CONCLUSION: The results of this study hold promise in providing valuable guidance to clinical practitioners for the differential diagnosis and early antimicrobial treatment of vertebral osteomyelitis.

A Novel Rat Model of Venous Hypertensive Myelopathy Produced by Arteriovenous Bypass Plus Venous Stenosis.

BACKGROUND AND OBJECTIVES: Venous hypertensive myelopathy (VHM), mainly induced by the spinal dural arteriovenous fistula, is a congestive spinal cord injury that currently has no appropriate animal model available in preclinical research. METHODS: Sprague Dawley rats (280-320 g) were used. The rats were divided into 3 groups: (1) Group 1, which underwent renal artery-dorsal spinal venous bypass (AVB group); (2) Group 2, which underwent renal artery-dorsal spinal venous bypass and drainage vein stenosis (AVB/VS group); and (3) Control group, with T13 dorsal vein ligation. The success of the model was assessed using Doppler ultrasound and 7.0-T magnetic resonance imaging. Transmission electron microscopy, histochemistry, proteomics, and western blot analysis were used to evaluate ultrastructural, pathological, and molecular features in the spinal cord and cerebrospinal fluid (CSF). RESULTS: The success rate of the arteriovenous bypass was 100% at 5 days and 83% at 2 weeks. The locomotor assessment showed decreased lower extremity strength in the AVB/VS group (P = .0067), whereas unremarkable changes were found in the AVB and Control groups. Histochemical staining suggested a 2-fold expansion of the dorsal spinal vein in the AVB/VS group, which was lower than that in the AVB group (P < .05); however, the former displayed greater myelin and neuronal damage (P < .05) and slight dilatation of the central canal (P > .05). Proteomics analysis revealed that the complement and coagulation cascade pathways were upregulated in the CSF of AVB/VS rats, whereas the C3 level was elevated both in the CSF and bilateral spinal cord. Furthermore, overexpression of C3, ITGB2, and CD9 in the spinal cord was confirmed by immunoblotting. CONCLUSION: These findings suggest that the AVB/VS model can effectively mimic the clinical and molecular characteristics of VHM. Furthermore, they suggest that impaired deep intramedullary venous drainage is the key reason for the VHM.

Angioarchitecture of Dural Arteriovenous Fistulas: Definition of Fistulous Points.

Because histopathological aspects of dural arteriovenous fistulas (DAVFs) are often lacking, there can be controversies regarding their angioarchitecture. Depending on various statements or DAVF types, the shunts can be situated directly on the sinuses, at the confluence of sinuses and cortical veins, in adjacent vascular structures surrounding the sinus, or, even, in the bone.1-5 Comprehensive knowledge of the intricate arteriovenous shunt anatomy is crucial for the secure and effective management of DAVFs.1 It has been confirmed that the dural arteries communicate with crack-like veins that connect ≥1 dural veins near the affected sinuses.3 In DAVFs, it is certain that ≥1 draining veins exist before draining into the venous sinus, in contrast to the commonly stated direct artery-to-sinus communication. Arteries branch and taper, and veins receive branches and thicken their lumens. We define fistulous points as the locations where the feeding arteries transition from thick to thin and the draining veins transition from thin to thick. We provide an image description based on superselective angiography.

Cervical Sagittal Alignment and Related Factor Analysis and Prediction Model in Patients Undergoing Revision Surgery After Anterior Cervical Fusion.

INTRODUCTION: Patients with myelopathy or radiculopathy commonly undergo anterior cervical fusion surgery (ACFS), which has a notable failure rate on occasion. The goal of this study was to compare revision and nonrevision surgery patients in cervical sagittal alignment (CSA) subsequent to ACFS; additionally, to identify the best CSA parameters for predicting clinical outcome after ACFS; and furthermore, to create an equation model to assist surgeons in making decisions on patients undergoing ACFS. METHODS: The data of 99 patients with symptomatic cervical myelopathy/radiculopathy who underwent ACFS were analyzed. Patients were divided into group A (underwent revision surgery after the first surgery failed) and group B (underwent only the first surgery). We measured and analyzed both preoperative and postoperative CSA parameters, including C2 slope, T1 slope, cervical lordosis C2-C7 (CL), C2-C7 sagittal vertical axis (C2C7 SVA), occiput-C2 lordosis angle (C0-C2), and chin brow vertical angle, and we further computed the correlation between the CSA parameters and created a prediction model. RESULTS: The (T1S-CL)-C2S mismatch differed significantly between groups A and B ([9.95 ± 9.95] 0 , [3.79 ± 6.58] 0 , P < 0.05, respectively). A significant correlation was observed between C2 slope and T1CL in group B relative to group A postoperatively (R 2 = 0.42 versus R 2 = 0.09, respectively). Compared with group B, patients in group A had significantly higher C2C7SVA values, more levels of fusion, and more smokers. The sensitivity, specificity, accuracy, and discrimination of the model were, respectively, 73.5%, 84%, 78.8%, and 85.65%. CONCLUSION: The causes of revision surgery in cervical myelopathic patients after anterior cervical corpectomy and fusion/anterior cervical diskectomy and fusion are multifactorial. (T1S-CL)-C2S mismatch and high C2C7SVA are the best cervical sagittal parameters that increase the odds of revision surgery, and the effect is more enhanced when comorbidities such as smoking, low bone-mineral density, and increased levels of fusion are taken into account.

Axl as a potential therapeutic target for adamantinomatous craniopharyngiomas: Based on single nucleus RNA-seq and spatial transcriptome profiling.

Craniopharyngiomas (CPs), particularly Adamantinomatous Craniopharyngiomas (ACPs), often exhibit a heightened risk of postoperative recurrence and severe complications of the endocrine and hypothalamic function. The primary objective of this study is to investigate potential novel targeted therapies within the microenvironment of ACP tumors. Cancer-Associated Fibroblasts (CAFs) were identified in the craniopharyngioma microenvironment, notably in regions characterized by cholesterol clefts, wet keratin, ghost cells, and fibrous stroma in ACPs. CAFs, alongside ghost cells, basaloid-like epithelium cells and calcifications, were found to secrete PROS1 and GAS6, which can activate AXL receptors on the surface of tumor epithelium cells, promoting immune suppression and tumor progression in ACPs. Additionally, the AXL inhibitor Bemcentinib effectively inhibited the proliferation organoids and enhanced the immunotherapeutic efficacy of Atezolizumab. Furthermore, neural crest-like cells were observed in the glial reactive tissue surrounding finger-like protrusions. Overall, our results revealed that the AXL might be a potentially effective therapeutic target for ACPs.

The subcommissural organ regulates brain development via secreted peptides.

The subcommissural organ (SCO) is a gland located at the entrance of the aqueduct of Sylvius in the brain. It exists in species as distantly related as amphioxus and humans, but its function is largely unknown. To explore its function, we compared transcriptomes of SCO and non-SCO brain regions and found three genes, Sspo, Car3, and Spdef, that are highly expressed in the SCO. Mouse strains expressing Cre recombinase from endogenous promoter/enhancer elements of these genes were used to genetically ablate SCO cells during embryonic development, resulting in severe hydrocephalus and defects in neuronal migration and development of neuronal axons and dendrites. Unbiased peptidomic analysis revealed enrichment of three SCO-derived peptides, namely thymosin beta 4, thymosin beta 10, and NP24, and their reintroduction into SCO-ablated brain ventricles substantially rescued developmental defects. Together, these data identify a critical role for the SCO in brain development.

Effects of calcium channel blockers on perioperative ischemic events in hypertensive patients with intracranial aneurysms undergoing neurointervention.

BACKGROUND: Although calcium channel blockers (CCBs) are useful in stroke prevention, their specific role in preventing stroke in hypertensive patients with intracranial aneurysms undergoing endovascular stent placement remains unclear. METHODS: We retrospectively examined 458 hypertensive patients with intracranial aneurysms who underwent stent treatment, drawn from a larger multicenter cohort comprising 1326 patients across eight centers. Patients were dichotomized into two groups according to use of a CCB. Propensity score matching (PSM) was performed to balance group differences in patient and aneurysm characteristics. We conducted a comparison of patient and aneurysm characteristics, ischemic complications, and clinical outcomes between the two groups. RESULTS: The CCB and non-CCB groups comprised 279 and 179 patients, respectively. PSM resulted in 165 matched pairs. After PSM, the incidence of ischemic events within 1 month of the procedure (4.2% vs 10.9%; P=0.022) and proportion of patients with modified Rankin Scale score >2 at last follow-up (1.5% vs 7.8%; P=0.013) were significantly lower in the CCB group. Among patients treated with combination therapy, inclusion of a CCB was associated with a lower incidence of ischemic events (1.5% vs 13.3%; P=0.345), but the difference was not statistically significant after correction. CONCLUSIONS: CCB use in hypertensive patients undergoing endovascular stenting for treatment of intracranial aneurysms is associated with a lower incidence of ischemic events and a lower incidence of unfavorable neurological outcomes, especially when used in combination therapy.

Isolated sinus dural arteriovenous fistulas: a single-center experience in 44 patients.

BACKGROUND: Isolated sinus dural arteriovenous fistulas (DAVFs) constitute a rare and distinctive subtype of DAVF, typically found in small case numbers or case reports. The optimal treatment for this DAVF type remains unclear. OBJECTIVE: This study aims to further detail the treatment outcomes of isolated sinus DAVFs in a sizable cohort from a single center. METHODS: A retrospective study was undertaken on a consecutive series of patients with isolated sinus DAVFs treated at a single institution from 2002 to 2022. The article delineates the clinical presentation, angiographic features, treatment strategy, clinical and angiographic outcomes, and complications. RESULTS: The cohort consisted of 31 males and 13 females, with an average age of 52.0 ± 15.5 years (range, 16-83). The success rate for trans-arterial embolization (TAE) was 97.3% (36/37). Transvenous embolization (TVE) with the reopening technique was successful in 3 of 4 patients (75.0%). Two open burr-hole TVE cases (66.7%, 2/3) and one surgery (100%) resulted in immediate complete closure of the fistula. Immediate complete occlusion was achieved in 93.2% (41/44) of cases. There was one major complication (2.3%, 1/44) and two fistulas recurred (9.5%, 2/21). CONCLUSIONS: The majority of isolated sinus DAVFs can be effectively treated with TAE using Onyx. TVE and surgery serve as alternative techniques when arterial access is deemed inappropriate or when complete occlusion cannot be attained with TAE. Complete embolization of isolated sinus DAVFs by TAE can typically be achieved without delay.

MIBPred: Ensemble Learning-Based Metal Ion-Binding Protein Classifier.

In biological organisms, metal ion-binding proteins participate in numerous metabolic activities and are closely associated with various diseases. To accurately predict whether a protein binds to metal ions and the type of metal ion-binding protein, this study proposed a classifier named MIBPred. The classifier incorporated advanced Word2Vec technology from the field of natural language processing to extract semantic features of the protein sequence language and combined them with position-specific score matrix (PSSM) features. Furthermore, an ensemble learning model was employed for the metal ion-binding protein classification task. In the model, we independently trained XGBoost, LightGBM, and CatBoost algorithms and integrated the output results through an SVM voting mechanism. This innovative combination has led to a significant breakthrough in the predictive performance of our model. As a result, we achieved accuracies of 95.13% and 85.19%, respectively, in predicting metal ion-binding proteins and their types. Our research not only confirms the effectiveness of Word2Vec technology in extracting semantic information from protein sequences but also highlights the outstanding performance of the MIBPred classifier in the problem of metal ion-binding protein types. This study provides a reliable tool and method for the in-depth exploration of the structure and function of metal ion-binding proteins.

Selenium Nanoparticles Attenuate Cobalt Nanoparticle-Induced Skeletal Muscle Injury: A Study Based on Myoblasts and Zebrafish.

Cobalt alloys have numerous applications, especially as critical components in orthopedic biomedical implants. However, recent investigations have revealed potential hazards associated with the release of nanoparticles from cobalt-based implants during implantation. This can lead to their accumulation and migration within the body, resulting in adverse reactions such as organ toxicity. Despite being a primary interface for cobalt nanoparticle (CoNP) exposure, skeletal muscle lacks comprehensive long-term impact studies. This study evaluated whether selenium nanoparticles (SeNPs) could mitigate CoNP toxicity in muscle cells and zebrafish models. CoNPs dose-dependently reduced C2C12 viability while elevating reactive oxygen species (ROS) and apoptosis. However, low-dose SeNPs attenuated these adverse effects. CoNPs downregulated myogenic genes and α-smooth muscle actin (α-SMA) expression in C2C12 cells; this effect was attenuated by SeNP cotreatment. Zebrafish studies confirmed CoNP toxicity, as it decreased locomotor performance while inducing muscle injury, ROS generation, malformations, and mortality. However, SeNPs alleviated these detrimental effects. Overall, SeNPs mitigated CoNP-mediated cytotoxicity in muscle cells and tissue through antioxidative and antiapoptotic mechanisms. This suggests that SeNP-coated implants could be developed to eliminate cobalt nanoparticle toxicity and enhance the safety of metallic implants.

[Trametenolic acid inhibits migration and invasion of hepatocellular carcinoma HepG2.2.15 cells via RhoC/ROCK1 pathway].

This study investigated the effect of trametenolic acid(TA) on the migration and invasion of human hepatocellular carcinoma HepG2.2.15 cells by using Ras homolog gene family member C(RhoC) as the target and probed into the mechanism, aiming to provide a basis for the utilization of TA. The methyl thiazolyl tetrazolium(MTT) assay was employed to examine the proliferation of HepG2.2.15 cells exposed to TA, and scratch and Transwell assays to examine the cell migration and invasion. The pull down assay was employed to determine the impact of TA on RhoC GTPase activity. Western blot was employed to measure the effect of TA on the transport of RhoC from cytoplasm to cell membrane and the expression of RhoC/Rho-associated kinase 1(ROCK1)/myosin light chain(MLC)/matrix metalloprotease 2(MMP2)/MMP9 pathway-related proteins. RhoC was over-expressed by transient transfection of pcDNA3.1-RhoC. The changes of F-actin in the cytoskeleton were detected by Laser confocal microscopy. In addition, the changes of cell migration and invasion, expression of proteins in the RhoC/ROCK1/MLC/MMP2/MMP9 pathway, and RhoC GTPase activity were detected. The subcutaneously transplanted tumor model of BALB/c nude mice and the low-, medium-, and high-dose(40, 80, and 120 mg·kg~(-1), respectively) TA groups were established and sorafenib(20 mg·kg~(-1)) was used as the positive control. The tumor volume and weight in each group were measured, and the expression of related proteins in the tumor tissue was determined by Western blot. The results showed that TA inhibited the proliferation of HepG2.2.15 cells in a concentration-dependent manner, with the IC_(50) of 66.65 and 23.09 µmol·L~(-1) at the time points of 24 and 48 h, respectively. The drug administration groups had small tumors with low mass. The tumor inhibition rates of sorafenib and low-, medium-and high-dose TA were 62.23%, 26.48%, 55.45%, and 62.36%, respectively. TA reduced migrating and invading cells and inhibited RhoC protein expression and RhoC GTPase activity in a concentration-dependent manner, dramatically reducing RhoC and membrane-bound RhoC GTPase. The expression of ROCK1, MLC, p-MLC, MMP2, and MMP9 downstream of RhoC can be significantly inhibited by TA, as confirmed in both in vitro and in vivo experiments. After HepG2.2.15 cells were transfected with pcDNA3.1-RhoC to overexpress RhoC, TA down-regulated the protein levels of RhoC, ROCK1, MLC, p-MLC, MMP2, and MMP9 and decreased the activity of RhoC GTPase, with the inhibition level comparable to that before overexpression. In summary, TA can inhibit the migration and invasion of HepG2.2.15 cells. It can inhibit the RhoC/ROCK1/MLC/MMP2/MMP9 signaling pathway by suppressing RhoC GTPase activity and down-regulating RhoC expression. This study provides a new idea for the development of autophagy modulators targeting HSP90α to block the proliferation and inhibit the invasion and migration of hepatocellular carcinoma cells via multiple targets of active components in traditional Chinese medicines.

Isolated spinal artery aneurysm: etiology, clinical characteristics, and outcomes.

OBJECTIVE: Isolated spinal aneurysms (ISAs) are rare causes of subarachnoid hemorrhage (SAH), which encompass a highly heterogeneous group of clinical entities with multifarious pathogeneses, clinical characteristics, and treatment strategies. Therefore, knowledge about the ISAs remains inadequate. In this study, the authors present a comprehensive analysis of clinical data associated with ISAs at their institutions to enhance the understanding of this disease. METHODS: Patients with ISAs confirmed by spinal angiography or surgery at the authors' institutions between 2015 and 2022 were included. Data regarding clinical presentation, lesion location, aneurysm morphology, comorbidities, treatment results, and clinical outcomes were reviewed. RESULTS: Seven patients with ISAs were included in the study. Among them, 4 patients (57.1%) experienced severe headache, and 3 patients (42.9%) reported sudden-onset back pain. Additionally, lower-extremity weakness and urinary retention were observed in 2 of these patients (28.6%). Four of the aneurysms exhibited fusiform morphology, whereas the remaining were saccular. All saccular aneurysms in this series were attributed to hemodynamic factors. Conservative treatment was administered to 3 patients, 2 of whom underwent follow-up digital subtraction angiography, which showed spontaneous occlusion of both aneurysms. Four patients ultimately underwent invasive treatments, including 2 who underwent microsurgery and 2 who received endovascular embolization. One patient died of recurrent SAH, while the remaining 6 patients had a favorable prognosis at the latest follow-up assessment. CONCLUSIONS: The morphology of aneurysms may be associated with their etiology. Saccular ISAs are usually caused by pressure due to abnormally increased blood flow, whereas fusiform lesions may be more likely to be secondary to vessel wall damage. The authors found that a saccular spinal aneurysm in young patients with a significant dilated parent artery may be a vestige of spinal cord arteriovenous shunts. ISAs can be managed by surgical, endovascular, or conservative procedures, and the clinical outcome is generally favorable. However, the heterogeneous nature of the disease necessitates personalized treatment decision-making based on specific clinical features of each patient.

Clinical outcomes and spinal growth after posterior hemivertebra resection and short segment fusion in children.

To evaluate the corrective effect of posterior hemivertebra resection and short-segment fusion surgery on pediatric patients and to assess the impact of short-segment fixation surgery on vertebral development during follow-up, a retrospective analysis was performed on 28 pediatric patients who underwent posterior hemivertebra resection surgery. The corrective effect was evaluated by comparing indicators such as segmental scoliosis Cobb angle, upper and lower compensatory curves and trunk balance at different time points. Meanwhile, the vertebral and spinal canal diameters of instrumented vertebrae and adjacent noninstrumented vertebrae were measured and compared to assess vertebral and spinal canal development. The correction rate of segmental scoliosis was 72.2%. The estimated mean vertebral volume of the instrumented vertebra was slightly lower than that of the unfused segment at the final follow-up, but the difference was not statistically significant. The growth rate of the spinal canal during follow-up was much smaller than that of the vertebral body. In summary, internal fixation at a young age shows no significant inhibitory effects on spinal development within the fusion segment. Posterior hemivertebra resection and short-segment fusion surgery are safe and effective.

Intraorbital Arteriovenous Fistulas: Case Series and Systematic Review.

BACKGROUND AND OBJECTIVES: Intraorbital arteriovenous fistulas (AVFs) are an extremely rare subtype of intracranial fistula with ophthalmic symptoms similar to cavernous sinus dural AVFs or carotid cavernous fistulas but worse visual outcomes. Here, we present a case series and thorough systematic review on intraorbital AVFs to demonstrate treatment modalities and address this rare type of AVF. METHODS: We conducted a retrospective study at a single center, in which we identified all cases of intraorbital AVFs that occurred between 2002 and 2022. We collected and analyzed data on demographics, fistula characteristics, treatment methods, clinical outcomes, and fistula closure. In addition, we conducted a systematic review of intraorbital AVFs. RESULTS: Seven cases in our center and 41 cases of intraorbital AVFs reported in the 35 articles were identified. At our center, transarterial embolization (TAE) (42.9%) alone resulted in immediate complete occlusion in 3 cases. Transvenous embolization (14.3%) resulted in one case of immediate complete occlusion. In 2 cases, surgery (28.6%) resulted in immediate complete occlusion. In one case, conservative treatment (14.3%) was used, and the fistula was eventually spontaneously occluded. Immediate complete occlusion rate was 85.7%. One blindness occurred (14.3%). In the literature reported, 3 cases (60%) of retinal artery occlusion were reported when performing TAE via the ophthalmic artery. Two fistulas recurred as reported. In 33 (80.5%) patients, the fistula was finally completely occluded. CONCLUSION: TAE via the ophthalmic artery carries a high risk of blindness and a low cure rate. Transvenous techniques such as conventional transvenous routes, surgical exposure, or direct puncture of the drainage vein have been used as the first line of treatment for intraorbital AVFs.