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.

Gene coexpression networks allow the discovery of two strictosidine synthases underlying monoterpene indole alkaloid biosynthesis in Uncaria rhynchophylla.

Plant-derived monoterpene indole alkaloids (MIAs) from Uncaria rhynchophylla (UR) have huge medicinal properties in treating Alzheimer's disease, Parkinson's disease, and depression. Although many bioactive UR-MIA products have been isolated as drugs, their biosynthetic pathway remains largely unexplored. In this study, untargeted metabolome identified 79 MIA features in UR tissues (leaf, branch stem, hook stem, and stem), of which 30 MIAs were differentially accumulated among different tissues. Short time series expression analysis captured 58 pathway genes and 12 hub regulators responsible for UR-MIA biosynthesis and regulation, which were strong links with main UR-MIA features. Coexpression networks further pointed to two strictosidine synthases (UrSTR1/5) that were coregulated with multiple MIA-related genes and highly correlated with UR-MIA features (r > 0.7, P < 0.005). Both UrSTR1/5 catalyzed the formation of strictosidine with tryptamine and secologanin as substrates, highlighting the importance of key residues (UrSTR1: Glu309, Tyr155; UrSTR5: Glu295, Tyr141). Further, overexpression of UrSTR1/5 in UR hairy roots constitutively increased the biosynthesis of bioactive UR-MIAs (rhynchophylline, isorhynchophylline, corynoxeine, etc), whereas RNAi of UrSTR1/5 significantly decreased UR-MIA biosynthesis. Collectively, our work not only provides candidates for reconstituting the biosynthesis of bioactive UR-MIAs in heterologous hosts but also highlights a powerful strategy for mining natural product biosynthesis in medicinal plants.

Filum terminale arteriovenous shunt with nidus structure: a report of rare condition and treatment consideration.

BACKGROUND:  In the literature, filum terminale arteriovenous shunts (FTAVSs) always feature a single shunt point. Nidus-type FTAVSs have rarely been reported, and the best treatment strategy is unclear. This is a report of one exceptional case of a nidus-type FTAVS and surgical treatment of the lesion. CASE DESCRIPTION: The patient suffered from cauda equina syndrome for 9 months. Magnetic resonance imaging and spinal angiography revealed a nidus-type FTAVF at the L2 level. Surgical resection was performed in the hybrid operating room, and the nidus was completely resected with the assistance of intraoperative methylene blue angiography and neurophysiological monitoring. The postoperative neurological function was stable. CONCLUSIONS: A nidus-type arteriovenous shunt could originate from the FT, and in such cases, complete surgical resection with intraoperative neurophysiological monitoring in a hybrid operating room should be suggested.

Prognostic Significance of Tumor Mutation Burden among Patients with Non-small Cell Lung Cancer Who Received Platinum-based Adjuvant Chemotherapy: An Exploratory Study.

This study aimed to investigate the prognostic significance of tumor mutation burden (TMB) among patients with non-small cell lung cancer (NSCLC) who received platinum-based adjuvant chemotherapy. Tumor tissue specimens after surgical resection were collected for DNA extraction. Somatic mutation detection and TMB analysis were conducted using next-generation sequencing (NGS). Recurrence status of the patients was assessed in the hospital during the adjuvant chemotherapy period, and long-term survival data of patients were obtained by telephone follow-up. Univariate analysis between TMB status and prognosis was carried out by survival analysis. A retrospective review of 78 patients with non-squamous NSCLC who received platinum-based adjuvant chemotherapy showed a median disease-free survival of 3.6 years and median overall survival (OS) of 5.3 years. NGS analysis exhibited that the most common mutated somatic genes among the 78 patients were tumor suppressor protein p53 (TP53), epidermal growth factor receptor, low-density lipoprotein receptor related protein 1B, DNA methyltransferase 3 alpha and FAT atypical cadherin 3, and their prevalence was 56.4%, 48.7%, 37.2%, 30.7%, and 25.6%, respectively. TMB status was divided into TMB-L (≤ 4.5/Mb) and TMB-H (> 4.5/Mb) based on the median TMB threshold. Relevance of TMB to prognosis suggested that the median OS of patients with TMB-L was significantly longer than that of patients with TMB-H (NR vs. 4.6, P = 0.014). Higher TMB status conferred a worse implication on OS among patients with non-squamous NSCLC who received platinum-based adjuvant chemotherapy.

The efficacy and deficiency of contemporary treatment for spinal cord arteriovenous shunts.

Contemporary treatments for spinal cord arteriovenous shunts are only based on clinicians' treatment experiences and expertise due to its rarity. We reviewed the clinical course of the largest multicentred cohort to evaluate the efficacy and deficiency of contemporary interventional treatments for spinal cord arteriovenous shunts. The clinical features, treatment results and clinical outcomes of 463 patients with spinal cord arteriovenous shunts were retrospectively assessed. The main outcome was the neurological deterioration that was evaluated based on the modified Aminoff and Logue scale. According to post-treatment digital subtraction angiography, complete obliteration was defined as disappearance of the intradural lesion, whereas partial obliteration was defined as any residual intradural lesion remaining visible and was further categorized as shunt-reduction obliteration (the nidus or shunt points were reduced) or palliative obliteration (only obliterated aneurysms or feeders). Cure rate was 40.6% for the whole cohort, 58.5% after microsurgery, and 26.4% after embolization. The curative resection was associated with non-metameric lesions, lesions with a maximum diameter <3 cm and lesions without anterior sulcal artery supply. The curative embolization was associated with fistula-type lesions, non-metameric lesions, and main drainage diameter <1.5 mm. The permanent treatment-related neurological deficits rate was 11.2% for the whole cohort, 16.1% after microsurgery, and 5.6% after embolization. The pretreatment clinical deterioration rate was 32.5%/year, which decreased to 9.3%/year after clinical interventions. Following partial treatment, the long-term acute and gradual deterioration rates were 5.3%/year and 3.6%/year, respectively. The acute deteriorations were associated with metameric lesions, craniocervical lesions, lesions with a maximum diameter ≥2 cm and residual aneurysm. Residual aneurysm was the only predictor of acute deterioration for non-metameric spinal cord arteriovenous shunts. The gradual deteriorations were associated with palliative obliteration, absence of pretreatment acute deterioration and intact main drainage. Although clinical risks of spinal cord arteriovenous shunts were reduced following clinical interventions, contemporary treatments for spinal cord arteriovenous shunt remains associated with considerable risks and incomplete efficacy. Individualized treatment plans should be adopted according to the angio-architectural features and major clinical risks of specific lesions. There is a higher opportunity for complete obliteration for lesions with simple angio-architecture. However, for most of spinal cord arteriovenous shunts with complex vascular anatomy, partial treatment is the only choice. For these patients, palliative obliteration targeting the aneurysms is recommended for reducing haemorrhagic risk, whereas shunt-reduction obliteration is necessary for non-haemorrhagic myelopathy. Contemporary treatment is ineffective in reducing haemorrhagic risk of incurable metameric spinal cord arteriovenous shunts.

Health-related quality of life outcomes and influencing factors in patients with unruptured intracranial aneurysms after endovascular treatment.

BACKGROUND: Health-related quality of life (HRQoL) is an important indicator when evaluating prognosis and disease-related treatments. Our current knowledge of the HRQoL outcomes of unruptured intracranial aneurysm (UIA) patients treated by the endovascular intervention appeared to be very limited. To fill this gap, the present study investigated the HRQoL outcomes and identified the influencing factors in UIA patients treated by endovascular intervention. METHODS: We conducted a single-center cross-sectional study on patients who underwent endovascular treatment for UIAs. HRQoL outcomes were assessed by the 36-item Short Form Health Survey (SF-36). The SF-36 results of the Chinese reference population were used as the reference data. The independent variables with a univariate analysis result of P < 0.05 were included in the multivariate analysis. Finally, multivariable linear regression analysis was performed to identify the factors influencing HRQoL. Bonferroni correction was utilized for multiple testing correction. RESULTS: A total of 200 patients (83 males and 117 females, mean age of 55.2 ± 9.48 years) with UIAs treated by endovascular intervention were enrolled. The scores of SF-36 in 8 domains for UIA patients treated by endovascular intervention did not all reach the average level of the Chinese reference population after an average recovery period of 30.67 ± 8.6 months. Ischemic cerebrovascular disease history, advanced age, and mRS progression at discharge were independent risk factors of HRQoL for UIA patients treated by endovascular intervention, but physical exercise at least once a week and daily sleep time no < 6 h were independent protective factors. CONCLUSION: The HRQoL of UIA patients treated by the endovascular intervention was decreased to varying degrees compared with those of the Chinese reference population. The influencing factors of HRQoL explored by this study provide insights for improving the clinical management and daily lives of these patients. HRQoL assessment should be included in future aneurysm prognostic studies to provide better evidence.

Comprehensive Treatment and Vascular Architecture Characteristic of High-Flow Vascular Malformations in Periorbital Regions.

OBJECTIVE: This study analyzed the vascular architecture characteristics of high-flow vascular malformations (VMs) in periorbital regions, as well as the treatment and imaging prognosis of occlusion degree of the outflow veins. METHOD: The clinical data of 24 patients with high-flow VMs in periorbital regions treated in our center from 2012 to 2019 were analyzed retrospectively, and the vascular architecture characteristics, treatment methods, and follow-up results were recorded. RESULTS: The vascular architecture of high-flow VMs in periorbital regions which usually contained the intracranial feeding arteries (24/24,100.0%) and intracranial outflow veins (18/24, 75.0%). The average age of first diagnosis was 23 ±â€Š16 years; the average age of treatment was 37 ±â€Š10 years; the median follow-up time was 42.5 months. Twenty-four patients with high-flow VMs in periorbital regions had 58 treatments in all. The imaging cure was achieved in 6 patients by complete occlusion of outflow veins, and no recurrence was found by DSA. Eighteen patients who get incomplete occlusion of outflow veins were given 49 treatments, and 8 patients had imaging recurrence. Seven patients (7/24, 29.2%) had treatment-related complications in all. CONCLUSIONS: Patients with high-flow VMs in periorbital regions are the most complex cases. The prognosis of patients whose outflow veins can be completely occluded is relatively good. The stepwise embolization while preserving organ function is advisable. Nevertheless, the incidence of treatment complications is still high.

Prevalence of and risk factors for anxiety and depression in Chinese patients with unruptured intracranial aneurysms treated by endovascular intervention.

BACKGROUND: Studies on anxiety and depression in unruptured intracranial aneurysm (UIA) patients after treatment via endovascular intervention are rare and controversial. We aimed to explore the prevalence of anxiety and depression among Chinese patients with UIAs treated by endovascular intervention and to identify which factors contribute to the development of these symptoms. METHODS: We performed a cross-sectional study on anxiety and depression in patients who underwent endovascular treatment for UIAs using the Hospital Anxiety and Depression Scale (HADS). The demographic, clinical and radiological data for all patients were retrospectively collected from the aneurysm database and medical records. Moreover, we utilized data from a large sample of 200 UIA patients and multivariate logistic regression analysis to investigate the risk factors for anxiety and depression in these patients. Candidate variables with P values less than 0.20 in univariate analysis were included in the multivariate logistic regression analysis. RESULTS: Two hundred patients returned completed questionnaires in this study. Of these 200 patients, 34 (17.0%) suffered from anxiety and 31 (15.5%) suffered from depression 30.67 ± 8.6 months after being discharged. The multivariate analysis results indicated that shorter sleep times were statistically significantly associated with depression (OR = 1.62, 95% CI: 1.14 ~ 2.29, P = 0.007, Adjusted P = 0.02). . CONCLUSION: The prevalences of anxiety and depression in UIA patients treated by endovascular intervention were 17.0 and 15.5%, respectively. Shorter sleep times were significantly associated with depression. Our findings provide evidence for the clinical and psychological management of these patients.

Using the modified Delphi method to research the influencing factors of long-term health-related quality of life in patients with unruptured intracranial aneurysms after endovascular treatment.

BACKGROUND: The purpose of this study was to use the modified Delphi method to identify the influencing factors of health-related quality of life (HRQoL) in patients with unruptured intracranial aneurysms (UIAs) after endovascular treatment. METHODS: A modified Delphi method to obtain expert consensus on the content of potential influencing factors of HRQoL in patients with UIAs treated by endovascular intervention was employed. The research team consists of three neuroradiologists and one epidemiologist from Xuanwu Hospital of Capital Medical University. They randomly selected 21 well-known experts in cerebrovascular disease diagnosis and treatment as participating experts. The importance of the indicator is based on the 5-Likert scale. The standard deviation (SD), coefficient of variation (CV), mean ( x ¯ ), and minimum and maximum scores of each indicator were calculated. The consistency was described by Kendall coefficient of concordance with a p value < 0.05 indicating that the expert consistency was high. RESULT: Twenty-one and 18 questionnaires were responded in 2 rounds, with effective response rates of 85.7% and 100.0%, respectively. The average authoritative coefficient (Cr) of all 21 experts was 0.88, familiarity with the indicators (Cs) was 0.82, and the judgment basis of the indicators (Ca) was 0.94. Eventually, the x ¯ values of arterial puncture hematoma, hyperlipidemia, gender, marital status, and hospitalization for other diseases were lower than 3.5; CV for marital status and gender was higher than 0.35. The Kendall coefficient of concordance in the first round was 0.19 (p < 0.001), and the second round was 0.15 (p < 0.001). CONCLUSION: In this study, the factors affecting the recovery of HRQoL after endovascular treatment in patients with UIAs were analyzed by the modified Delphi method, which provided a valuable evidence for the clinical management and daily life guidance for UIAs patients.

Microsurgical and Endovascular Treatment Outcomes in Pericallosal Artery Aneurysms: A Single Center Retrospective Analysis.

AIM: To summarize the clinical outcomes, follow-up results and to discuss the optimal therapeutic strategy for pericallosal artery aneurysms (PAAs). MATERIAL AND METHODS: From January 2013 to May 2017, the charts of 49 patients with PAAs, representing 2.43% of 2,018 consecutive patients with intracranial aneurysms (IAs) were reviewed. The clinical and radiological data of these patients were retrospectively analyzed. RESULTS: There were no technical failures in the clipping group, but one patient in the coiling group presented rebleeding during the operation, resulting in a poor prognosis. Although the difference was not significant, the coiling group had a better complete recovery rate than the clipping group [overall: coiling, n=20 (87.0%) vs clipping, n=11 (68.8%), p=0.33; unruptured PAAs: coiling, n=12 (92.3%) vs clipping, n=5 (83.3%); ruptured PAAs: coiling, n=8 (80%) vs clipping, n=6 (60%), p=0.63]. One patient in the coiling group exhibited recurrence. No patients experienced rebleeding during the follow-up period in either group. CONCLUSION: In our study, both endovascular coiling and microsurgery were technically feasible and achieved favorable clinical outcomes in patients with PAAs. Longer radiological follow-up is necessary. Patients should be evaluated by a multidisciplinary team prior to determining the optimal treatment modality.

Morphological Characteristics of Pericallosal Artery Aneurysms and Their High Propensity for Rupture.

BACKGROUND: Compared with intracranial aneurysms (IAs) at other locations, pericallosal artery aneurysms (PAAs) have demonstrated an extremely high risk of rupture. However, owing to their rarity, our understanding of their morphological characteristics has been limited, and whether the morphological characteristics of PAAs contribute to this high rupture risk has remained unexplored. In the present study, we aimed to provide a detailed description of the morphological characteristics of PAAs and investigate the association between its morphology and rupture risk compared with anterior circulation IAs at other locations. METHODS: A total of 40 patients with 45 PAAs and 348 patients with 392 anterior circulation IAs at other locations were recruited. The clinical and radiological data for these patients were retrospectively reviewed. The differences in the morphological parameters, including the aneurysm diameter, neck width, height, width, parent artery diameter, inflow angle, aspect ratio (AR), size ratio (SR), and aneurysm diameter/width ratio, between PAAs and other IA groups were compared. RESULTS: Of the 45 PAAs, 22 (48.9%) had ruptured. The proportion of ruptured aneurysms was greater for PAAs than for anterior circulation IAs at other locations. For both ruptured and unruptured anterior circulation IAs, PAAs had the highest AR and SR among all IA groups and had the largest inflow angle. CONCLUSION: The morphological characteristics of PAAs are unique. Compared with other anterior circulation IAs, PAAs have significantly increased ARs, SRs, and inflow angles, which, ultimately, promote their high propensity toward rupture.

Natural history of spinal cord arteriovenous shunts: an observational study.

The natural history of intradural spinal cord arteriovenous shunts is unknown. We performed an observational study in a consecutive patient cohort with symptomatic intradural spinal cord arteriovenous shunts who were admitted to three institutes to investigate the clinical course of this complex disease, which would provide valuable evidence to inform clinical decision-making. The clinical course of patients with symptomatic intradural spinal cord arteriovenous shunts from initial presentation to occurrence of clinical deterioration, initiation of treatment, or last follow-up was analysed. Patients with at least 1 month of observation were included in this study. Clinical onset and deterioration patterns were divided into acute and gradual. Annual and cumulative rates of clinical deterioration as well as their risk factors were analysed using Kaplan-Meier life table analysis and Cox proportional hazards model. To assess risks and benefits of treatment, post-treatment clinical courses were further assessed. Four hundred and sixty-six patients with a mean observational period of 36.9 ± 58.8 months were included; 56.7% of patients presented with acute onset, of whom 77.3% experienced spontaneous recovery. Age of onset older than 28 years, initial modified Aminoff and Logue scale of >3, mid-thoracic lesions and non-ventral lesions were independent predictors of failure for spontaneous recovery. The annual risk of general, acute and gradual clinical deterioration after onset was 30.7%, 9.9% and 17.7%, respectively. Risk of deterioration was highest in the early period after initial onset. Acute onset was the only independent risk factor [hazard ratio 1.957 (95% confidence interval, CI 1.324-2.894); P = 0.0008] of acute deterioration and gradual onset was the strongest predictor [hazard ratio 2.350 (95% CI 1.711-3.229); P < 0.0001] of the gradual deterioration among all the stratifying factors. After invasive treatment, complete obliteration was achieved in 37.9% of patients (138 of 364) and improved or stable clinical status was noted in 80.8% of patients. Forty-two patients (11.5%) experienced permanent complications. Overall post-treatment deterioration rate was 8.4%/year, and 5.3%/year if permanent complications were excluded. The natural history of symptomatic spinal cord arteriovenous shunts is poor, especially in the early period after onset, and early intervention is thus recommended. Initial onset pattern significantly affects the natural history of the lesion, which prompts a differentiated treatment strategy.

Filum Terminale Arteriovenous Fistulas with Multiple Shunt Points: A Report of Two Exceptional Cases.

BACKGROUND: Filum terminale arteriovenous fistula (FTAVF) with multiple shunt points has not been reported in the literature. In previous studies, the angioarchitecture of FTAVFs was always featured with only one single shunt point, and such a uniformity had established the preconceived and conventional understanding of FTAVFs for clinicians. CASE DESCRIPTION: The authors describe 2 exceptional cases of FTAVFs with multiple shunt points confirmed by open surgery, which means that the above understanding may lead to misdiagnosis and incomplete treatment in future. The surgery of both cases was performed in a hybrid operating room, and all of shunt points were obliterated with the help of intraoperative digital subtraction angiography. CONCLUSIONS: The exceptional finding of these 2 cases is a renewal of the conventional understanding of FTAVFs, not only for the angioarchitecture of the lesions but also for the treatment strategy.

Diagnostic significance of microRNAs as novel biomarkers for bladder cancer: a meta-analysis of ten articles.

BACKGROUND: Previous studies have revealed the importance of microRNAs' (miRNAs) function as biomarkers in diagnosing human bladder cancer (BC). However, the results are discordant. Consequently, the possibility of miRNAs to be BC biomarkers was summarized in this meta-analysis. METHODS: In this study, the relevant articles were systematically searched from CBM, PubMed, EMBASE, and Chinese National Knowledge Infrastructure (CNKI). The bivariate model was used to calculate the pooled diagnostic parameters and summary receiver operator characteristic (SROC) curve in this meta-analysis, thereby estimating the whole predictive performance. STATA software was used during the whole analysis. RESULTS: Thirty-one studies from 10 articles, including 1556 cases and 1347 controls, were explored in this meta-analysis. In short, the pooled sensitivity, area under the SROC curve, specificity, positive likelihood ratio, diagnostic odds ratio, and negative likelihood ratio were 0.72 (95%CI 0.66-0.76), 0.80 (0.77-0.84), 0.76 (0.71-0.81), 3.0 (2.4-3.8), 8 (5.0-12.0), and 0.37 (0.30-0.46) respectively. Additionally, sub-group and meta-regression analyses revealed that there were significant differences between ethnicity, miRNA profiling, and specimen sub-groups. These results suggested that Asian population-based studies, multiple-miRNA profiling, and blood-based assays might yield a higher diagnostic accuracy than their counterparts. CONCLUSIONS: This meta-analysis demonstrated that miRNAs, particularly multiple miRNAs in the blood, might be novel, useful biomarkers with relatively high sensitivity and specificity and can be used for the diagnosis of BC. However, further prospective studies with more samples should be performed for further validation.

A New Type of Spinal Epidural Arteriovenous Fistulas Causes Spinal Epidural Hemorrhage: An Analysis of Five Cases and Natural History Consideration.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEDAVFs) are peculiar and poorly understood lesions with a poorly understood natural history. They usually are subclassified into 2 types according to their drainage components. This study aimed to describe a new type of SEDAVFs that is featured with a unique drainage pattern and present our natural history hypothesis of SEDAVFs. METHODS: Five SEDAVF cases of the new type were reviewed retrospectively from a high case-volume spinal vascular malformation database. The clinical manifestations, neuroradiologic findings, angioarchitecture, treatment strategies, and clinical outcomes were assessed. RESULTS: All patients presented with spontaneous spinal epidural hematoma, and 2 of them exhibited rebleeding. The median age at the initial episode was 20 years. Spinal digital subtraction angiography revealed slow-flow epidural fistulas drained by spinal epidural venous plexus without intradural drainage or engorged venous pouches in all 5 patients. Three patients underwent microsurgical treatment. The outcomes of all of the patients were favorable. CONCLUSIONS: Our study reported a special type of hemorrhagic SEDAVF without an intradural drainage component or epidural mass effect. The key diagnostic clue was early opacification of spinal epidural venous plexus on spinal angiogram. We believe SEDAVFs may form at an early age and gradually develop with time. Different types of SEDAVFs may represent different developing stages of one disease, and our type may represent the early stage of SEDAVFs.

Spontaneous Spinal Epidural Hematoma: A Study of 55 Cases Focused on the Etiology and Treatment Strategy.

BACKGROUND: Spontaneous spinal epidural hematoma (SSEH) is a rare neurologic emergency of the spinal cord. Its cause and treatment strategy remain controversial. This study aimed to evaluate a significant cause of SSEH and to discuss the treatment strategy according to the clinical outcomes of patients in 2 institutions. METHODS: Fifty-five cases of SSEH treated at our institutions between February 2002 and February 2016 were retrospectively analyzed. RESULTS: The mean age of the first SSEH onset was 31.8 years. The follow-up rate was 72.7%, with 28 patients (70%) showing satisfactory clinical outcomes. Forty patients received preoperative spinal digital subtraction angiography. Spinal epidural (extradural) arteriovenous fistula was detected in 6 patients (15%), 5 of whom showed 1 type of special slow-flow shunt. Nineteen patients (34.5%) suffered from multiple episodes until they underwent invasive treatments or last follow-up. Rebleeding was confirmed in 8 patients. None of the patients had a subsequent episode or rebleeding after invasive treatment. The risk factors for poor clinical outcome included advanced age at initial onset (P = 0.020), a short progression interval (P = 0.030), no symptom relief after admission (P = 0.011), hypesthesia (P = 0.017), complete spinal cord injury (P = 0.001), and hematoma below the T4 level (P = 0.014). CONCLUSIONS: Spinal epidural (extradural) arteriovenous fistula is a significant cause of SSEH. Standard spinal digital subtraction angiography is necessary for patients with SSEH. Conservative treatment could not prevent occurrence of multiple episodes or rebleeding in patients. Microsurgery should be recommended as the preferred treatment strategy for SSEH. Endovascular embolization is also recommended if applicable.