Coexistence of neural tube defects and spinal arteriovenous shunts: a case series and review of literature.

BACKGROUND: Spinal arteriovenous shunts and spinal dysraphism both have a different underlying cause, disease spectrum and developmental process; hence, these entities rarely coexist in a patient. Here, we reported four cases of coexistence of adult-onset spinal arteriovenous shunt and spinal dysraphism in the same patient along with their therapeutic embolisation. Additionally, we conducted an extensive literature review to explore the potential theories and explanations for this coexistence. METHODS: We retrospectively searched our imaging database from January 2015 to December 2023 to identify instances of spinal arteriovenous shunts occurring in patients with spinal dysraphism or neural tube defect disorders. MRI and angiographic imaging, clinical presentation, treatment and follow-up were analysed. RESULTS: Four patients with arteriovenous fistula/shunt and spinal dysraphism were included in the study. The mean age of presentation was 35.5 years. The most common symptoms were sensory disturbance and motor weakness. Arteriovenous fistula or shunt was located at the lumber region in one patient and at the sacral region in three cases. Two patients have a prior history of surgery in first decade. Two patients were treated with glue embolisation. The internal iliac artery was a common feeder in all cases. CONCLUSIONS: The rare coexistence of neural tube defects with spinal vascular abnormalities should be considered when assessing a middle-aged patient with neural tube defect and myelopathy. Correct diagnosis can help in treatment planning and thereby improve prognosis.

Spontaneous spinal hematomas: A case series.

PURPOSE: Spontaneous spinal hematoma (SSH), a rare neurological disorder, demands immediate diagnostic evaluation and intervention to prevent lasting deficits. This case series analyzes instances, particularly highlighting cases where vascular causes were identified despite inconclusive initial imaging. METHODS: In a retrospective study of 20 patients treated for SSH at a Level I spine center from 01/01/2017 to 11/15/2023, we examined demographics, clinical presentation, imaging, and treatment details. Excluding traumatic cases, we present 4 instances of SSH associated with diverse vascular pathologies. RESULTS: Patient ages ranged from 39 to 85 years, with a median age of 66 years. 45% were male, and 55% were female. Among 20 cases, 14 were epidural hematomas, 4 subdural, 1 combined epidural and subdural, and 1 subarachnoid hemorrhage. 85% presented with neurological deficits, while 3 solely had pain-related symptoms. 55% were under anticoagulant medication, and vascular anomalies were found in 25% of cases. The cause of SSH remained unclear in 20% of cases. MRI was performed for all patients, and DSA was conducted in 25% of cases. The 4 highlighted cases involved individuals with distinct vascular pathologies managed surgically. CONCLUSION: Urgent attention is crucial for SSH due to possible lasting neurological consequences. The study emphasizes comprehensive diagnostics and surgical exploration, especially in cases with unclear etiology, to identify and address vascular causes, preventing hematoma progression or recurrence. Despite their rarity, vascular malformations contributing to spinal hematomas warrant particular attention.

A Rare Case of Cervical Spinal Arteriovenous Malformation: A Case Report.

Arteriovenous malformation (AVM) is an abnormal connection of vasculature resulting in capillary bed bypassing and leading to neurological deterioration and high risk of bleeding. Intramedullary AVMs in the cervical spinal cord are rare and require precise diagnostics and treatment. We present a clinical case of recurrent AVMs in a 28-year-old Caucasian female with sudden and severe neck pain and variable neurological symptoms along with current diagnostic and treatment modalities. Conservative treatment was partially effective. MRI and DSA confirmed AVMs at C4 level with subsequent several endovascular treatment sessions at the age of 15 and 24 with mild neurological improvement. Afterwards the patient underwent rehabilitation with minor neurological improvement. This case highlights the clinical progression and treatment of AVMs along with showcasing current pathophysiology, classification, and imaging.

Vascular Malformations of the Spinal Cord in Children.

Vascular malformation of the spinal cord in children is a rare and complicated disease spectrum. We will start from the basic spinal cord vascular anatomy and the controversial classification of this kind of disease. Then, we will elaborate the clinical manifestations, diagnostic imaging and treatment of pediatric spinal vascular malformations based on the practical experience of our center and from literature.

Thoracic spinal arteriovenous malformation in a 16-year-old presenting with headache.

Spinal arteriovenous malformations (sAVM) are abnormally developed spinal blood vessels with an increased risk of hemorrhage. Current literature regarding sAVMs is sparse and describes classic presentations in very young children or adults. We report a unique case of a sAVM in an adolescent patient. A 16-year-old female patient presented to the emergency department with a 3-day history of headaches. Initial CT showed no abnormalities. Worsening headaches led the patient to a neurology clinic and a fundoscopy revealed papilledema. The patient was transferred to a pediatric emergency department where repeat head CT showed a possible subarachnoid hemorrhage, and a cranial MRI/MRV showed what appeared to be a non-occlusive sinus venous thrombosis. CT angiography of the head and neck showed no evidence of thrombosis, but it did reveal possible upper thoracic vascular abnormalities. Thoracic MRI revealed an intradural sAVM at T3-T5. The sAVM was successfully resected with thoracic laminectomy with reconstructive laminoplasty. The patient experienced complications with development of right lower extremity motor and sensory deficits intra-op, but is showing continued improvement. This unique case encourages emergency medicine clinicians to expand the differential diagnoses for pediatric patients presenting with a headache and intracranial hypertension without a clear intracranial cause.

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.

The role of spinal angiography in the evaluation and treatment of pediatric spinal vascular pathology: a case series and systematic review.

OBJECT: While it has been extensively studied in adults, the role of spinal angiography in children with suspected spinal vascular malformations is not fully characterized. With special implications regarding technique, radiation dose, and pathology, we sought to review our single-center experience with pediatric spinal vascular pathology and use a systematic review of the literature to further identify its role in pediatrics. METHODS: A retrospective chart review was conducted under IRB approval for all patients age 0-18 years old who underwent spinal angiography at our institution between 2007 and 2018 for concern for spinal vascular pathology. A simultaneous systematic review was conducted via dedicated search terms in two distinct databases and reviewed to identify all studies referring to spinal angiography or angiograms in pediatric patients. RESULTS: Six patients were included. Three patients (50%) had vascular malformations confirmed on diagnostic angiography and underwent subsequent endovascular treatment. Two patients (33.3%), one with hematomyelia and one with spinal cord infarction, had negative diagnostic angiograms. One patient (16.7%) had a spinal tumor and underwent angiography for further evaluation preoperatively. Spinal angiography was used to aid in diagnosis, preoperative planning, and treatment in these cases. It was demonstrated to be safe in this patient population, with no untoward events, minimal radiation dose, and possible therapeutic applications in select cases. The systematic review identified 11 studies regarding pediatric spinal angiography. These ranged from single case reports to case series of up to 38 patients and highlighted the role of spinal angiography in diagnosis, endovascular treatment, preoperative planning, and postoperative follow-up. CONCLUSIONS: Spinal angiography may be used in a variety of scenarios to better understand the architecture of vascular spinal lesions and facilitate endovascular intervention. While its application in both adult and pediatric pathology is limited to select cases, spinal angiography remains a key diagnostic procedure when approaching vascular lesions or tumors of the spine, assessing for etiology of spinal cord infarcts, and in the evaluation of unexplained hemorrhage in the spinal canal.

Quantitative protein profiling and pathway analysis of spinal arteriovenous malformations.

Spinal arteriovenous malformations (sAVM) are rare and heterogeneous group of blood vessel disorders that affect spinal cord function directly or indirectly; however, the pathogenesis of sAVM is still unclear. In this study, we compared four sAVM specimens obtained during surgery and donated control samples in a Tandem Mass Tag (TMT)-labeled proteomic analysis. We identified 3101 proteins, 654 of which were differentially expressed in sAVM samples compared with the controls. Of these, 96 proteins were upregulated and 358 proteins were downregulated. Gene ontology (GO) analysis revealed that extracellular matrix organization in the biological process category and integrin-binding proteins in the molecular function category were the most enriched items. Two significant differentially expressed proteins (MYLK and MMP9) were verified by Western blot analysis. The pathway analysis indicated that the differentially expressed proteins in the pathways of angiogenesis, focal adhesion and cytoplasmic ribosome contributed to sAVM. The changes in protein profiles identified in this proteomic study provide an improved understanding of the pathogenesis of sAVM. The proteomics data are available via ProteomeXchange with identifier PXD007982.

Pediatric Dilemma: Endovascular versus Surgical Intervention for Spinal Vascular Malformations.

OBJECTIVE: Spinal arteriovenous malformations (AVM) manifest in the pediatric population very differently from the ones in adulthood. Despite that fact, the treatment strategy is quite the same, which provokes a question - whether some of the therapies have an advantage and if so, in which age group. METHODS: For this reason, the authors searched the world literature between 1989 and 2018 for spinal AVM in children and further categorized the studies into two age groups: < 12 and ≥12. RESULTS: The total number of included studies in this meta-analysis is 35. Seventeen of them are on the subject of AVM and 15 on the subject of arteriovenous fistula. Three studies encompass both types of lesions. CONCLUSION: After processing the data, we observed that there is no relationship between age group and the utilized management, except for the endovascular AVF in children less than 12 years of age. Because of this, it should be strongly considered in further management planning.

Spinal vascular malformations: treatment strategies and outcome.

Spinal vascular malformations (SVMs) are a heterogeneous group that can cause acute, subacute, or chronic spinal cord dysfunction. The majority of the patients present to neurosurgical attention after a protracted course with severe neurological dysfunction. Spinal vascular lesions comprise approximately 3-4 % of all intradural spinal lesions. They are pathologically similar to their intracranial counterparts, but their clinical impact is often comparatively worse. Early, correct recognition of the pathology is mandatory to halt the progression of the disease and minimize permanent spinal cord injury. The first clinical observation of a SVM was published in 1890, but it was not until 1914 that the first successful surgical treatment of a spinal vascular malformation was reported. Intervention-either by microsurgical or endovascular means-aims to halt or reverse the progressive neurological deterioration by eliminating flow through the abnormal fistulous or nidal connections, and restoring normal spinal cord perfusion and intravascular pressures. In fact, complex spinal arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) frequently require a multimodality approach that utilizes both microsurgery and endovascular embolization effectively. The goal of this review is to describe the various types of vascular malformations of the spine, their pathophysiology, clinical presentation, treatment strategies, and outcome. For purposes of discussion on the current manuscript, vascular malformations of the spine were divided into arteriovenous fistulas (AVFs) and arteriovenous malformations (AVMs). Spinal cord aneurysms are extremely rare, and the majority of the lesions that come to the neurosurgeon's attention are concomitant to a spinal AVM.

Spinal extradural arteriovenous fistula with intradural drainage: three surgical cases with long-term follow-up.

Spinal extradural arteriovenous fistulas (SEDAVF) with intradural drainage are uncommon vascular lesions that cause venous congestive myelopathy. We present three SEDAVF with intradural drainage treated with surgical disconnection of the intradural drainage via a single level laminectomy, followed by transarterial embolization (TAE) with Onyx if spontaneous thrombosis of the extradural fistula did not occur spontaneously. All patients improved their neurological condition and no congestive myelopathy recurrence was noted after mean follow-up of 84 months. We believe that SEDAVF with intradural drainage constitute a specific entity that should be included in the classifications of spinal arteriovenous malformations.

Diffuse subarachnoid and intraventricular hemorrhage as the presenting sign of a conus medullaris arteriovenous malformation: Case report.

Spinal arteriovenous malformations (AVMs) are rare vascular lesions that usually present with progressive myelopathy or less frequently, with acute neurological deficit due to hematomyelia or spinal subarachnoid hemorrhage (SAH). There are few reports of concomitant cerebral SAH and intraventricular hemorrhage (IVH) following rupture of a spinal AVM. Herein, we present a rare case of conus medullaris arteriovenous malformation, out-breaking with loss of consciousness due to SAH and IVH.

Treatment of conus medullaris arteriovenous malformation: the role of microsurgical treatment.

OBJECTIVE: Conus medullaris arteriovenous malformation (AVM) is rare and challenging to treat. To better define the presentation, prognosis, and optimal treatment of these lesions, the authors present their treatment experiences for conus medullaris AVM. METHODS: Eleven patients with AVM of the conus medullaris were identified between March 2013 and December 2021. Among these patients, 7 who underwent microsurgical treatment were included. Patient data, including age, sex, symptoms at presentation, neurological status, radiological findings, nidus depth (mainly pial lesion vs intramedullary lesion), type of treatment, and recurrence at follow-up, were collected. Postoperative angiography was performed in all patients. Spinal cord function was evaluated using the Frankel grade at the time of admission and 1 year after surgery. RESULTS: All 7 patients presenting with myeloradiculopathy were treated surgically. Four patients (57.1%) underwent endovascular embolization, followed by resection. The other 3 patients underwent microsurgery only. Complete occlusion was confirmed with postoperative angiography in all patients. Of the 3 patients who were nonambulatory before surgery (Frankel grade C), 2 were able to walk after surgery (Frankel grade D) and 1 remained nonambulatory (Frankel grade C) at 1-year follow-up. CONCLUSIONS: Based on the authors' clinical experiences, the results of multimodal treatment for conus medullaris AVM are good, with microsurgical treatment playing an important role. The microsurgical strategy can differ depending on the location of the nidus, and when possible, good results can be expected through microsurgical resection.

Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review.

Spinal dural arteriovenous fistula (SDAVF) is among the most common arterial shunt diseases typically found in middle aged or older men. Herein, we aimed to clarify the reasons for misdiagnoses and delayed diagnoses of SDAVF, determine how these affect prognoses, and establish how they can be prevented. We conducted a PubMed/MEDLINE literature search using "spinal dural arteriovenous fistula", "delayed diagnosis", "late diagnosis", and "misdiagnosis" terms. We identified 18 articles, including 965 SDAVF cases. Patients were predominantly males (71.8-100.0%) (mean age: 53.5-71.0 years). Misdiagnoses rates varied (17.5-100.0%) and encompassed many conditions. The mean time between early manifestations and confirmed diagnosis was approximately 10-15 months and from the first radiologic image revealing dural arteriovenous fistula (DAVF) features to diagnosis was 9.2-20.7 months. Posttreatment outcomes showed a significant improvement in motor functions, gait, and micturition, particularly in patients exhibiting preoperative symptoms over a short period. SDAVF is frequently misdiagnosed or subject to delayed diagnosis, causing poor clinical outcomes. SDAVF symptoms including progressive lower-limb weakness, paresthesia, and vesicorectal dysfunction are indications for spinal magnetic resonance imaging with subsequent spinal angiography, wherein DAVF is evidenced by extensive T2 hyperintensity and flow-void abnormalities. We reported a representative case with delayed diagnosis.

Diagnostic, clinical management, and outcomes in patients with spinal dural arteriovenous fistula.

Background: Spinal dural arteriovenous fistulas (SDAVFs) are rare spinal vascular malformations, but account for 70 to 80% of all spinal arteriovenous malformations. SDAVFs can be treated either surgically or endovascularly, with surgical treatment appearing to lead to higher closure rates. Our aim was to analyze the demographic data, diagnostic history, treatment characteristics and clinical short- and long-term outcomes. Methods: The medical records of 81 patients who underwent surgical (n = 70, 86.4%) and endovascular (n = 11, 13.6%) treatment for SDAVF at a university hospital between 2002 and 2023 were retrospectively analyzed. Results: SDAVF was observed more frequently in men than women (61, 75.3% vs. 20, 24.7%) with a mean age of 63.5 ± 12.7 years and a mean duration of symptoms to diagnosis of 12.0 ± 12.8 months. The most common first symptom was gait disturbance (36, 44.4%), followed by sensory disturbance (24, 29.6%). The location of the fistula point was most common in the lower thoracic region (36, 44.5%), followed by the lumbar region (23, 28.4%). Incomplete or failed occlusion of the fistula occurred in 8 patients (9.9%), with 6 patients (7.4%) undergoing further treatment either surgically or endovascularly. Treatment- or hospital-related complications were observed in 16 patients (19.8%). A single-level laminectomy was the most common approach (31, 44.3%), followed by single-level hemilaminectomy (28, 40.0%), and unilateral interlaminar fenestration (11, 15.7%). Back pain or radiculopathy was observed in 58% of patients (47/81) pre-treatment and had already decreased to 24.7% at hospital discharge (p < 0.001). No significant differences were observed in sensory disturbances (p = 0.681). The median of American Spinal Injury Association motor score (ASIA-MS) was 94 [82.5-100] at admission, 98 [86.5-100] at hospital discharge, 100 [90-100] at the first, second, and third follow-up (p = 0.019). The median modified Aminoff-Logue scale (mALS) was 5 [2-7] at admission, 3 [1-6] at hospital discharge, 2 [1-5] at the first follow-up, 2 [0.5-5] at the second follow-up and 2 [1-7] at the third follow-up (p = 0.006). Conclusions: SDAVF occurs predominantly in men in the 6th decade of life and can be safely and effectively treated surgically and endovascularly, improving symptoms such as pain and motor deficits, gait disturbances as well as bowel and bladder dysfunction, but not sensory disturbances.

Spontaneous obliteration of a spinal perimedullary fistula.

We herewith report a young patient who had an incidental spinal vascular malformation of the cervicomedullary junction discovered during a work-up for anosmia. Angiography demonstrated a perimedullary spinal arteriovenous fistula with supply from lateral spinal arteries arising from bilateral V3 level segmental arteries. It was decided to manage the patient conservatively with magnetic resonance imaging monitored biannually. On a recent follow-up magnetic resonance, nearly 10 years later, we noted a subtle change in caliber and imaging characteristics at the posterior margin of the cervical medullary junction. Repeat digital-subtraction angiography showed no evidence of early venous filling from the previously involved branches. Microcatheter exploration of the right lateral spinal artery confirmed spontaneous occlusion of the spinal perimedullary arteriovenous fistula, without any persistent shunting. Spontaneous resolution of a spinal vascular malformation is rare; this case demonstrates the dynamic nature of shunting vascular malformations and that spontaneous obliteration of arteriovenous shunts is possible.

Spinal arteriovenous malformation with a calcified nodule: illustrative case.

BACKGROUND: This article describes a rare case of cervical spinal arteriovenous malformation (AVM) mimicking a neurogenic spinal tumor. OBSERVATIONS: A 22-year-old female presenting with a C6-7 AVM with a calcification nodule experienced new-onset acute right upper radiculopathy associated with extradural compression of the spinal cord. Note that spinal AVMs with a calcified nodule are rare. Endovascular embolization is generally used to relieve the symptoms of AVM; however, this procedure cannot relieve cord compression, particularly in cases complicated by calcified nodules. This article discusses treatment options. LESSONS: Decompression surgery is preferable to endovascular embolization because it alleviates symptoms while preventing cord compression and minimizing the risk of recurrence.

Recurrence Rates Following Treatment of Spinal Vascular Malformations: A Systematic Review and Meta-Analysis.

BACKGROUND: Spinal vascular malformations (SVMs), including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), are a varied group of vascular lesions that can be subclassified according to localization, vascular structure, and hemodynamics. Early intervention is necessary to halt progression of disease and minimize irreversible dysfunction. We sought to characterize initial treatment success and recurrence rates following interventional treatment of various types of SVMs. METHODS: A systematic review and meta-analysis were performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. SVMs were categorized into 4 groups: dural AVFs, perimedullary AVFs, intramedullary AVMs, and extradural-intradural AVMs (e.g., epidural, paraspinal). Initial occlusion, recurrence, and complication rates were compared using random-effects analysis. RESULTS: There were 112 manuscripts included, with a total of 5626 patients with SVM. For treatment, 2735 patients underwent endovascular embolization, 2854 underwent surgical resection, and 37 underwent stereotactic radiosurgery. The initial treatment success and overall recurrence rates following surgical resection of all SVMs were 89.5% (95% CI: 80.5%-98.5%) and 2.3% (95% CI: 0.9%-3.7%), respectively. Those rates following endovascular embolization were 55.9% (95% CI: 30.3%-81.5%) and 27.7% (95% CI: 11.2%-44.2%), respectively. Higher rates of initial treatment success and lower rates of recurrence with surgery were observed in all subtypes compared to embolization. Overall complication rates were higher after embolization for each of the SVM categories. CONCLUSIONS: Surgical resection of SVMs provided higher rates of initial complete occlusion and lower rates of recurrence than endovascular techniques. Attaining technical success through obliteration must still be weighed against clinical impact and natural history of the specific vascular malformation.

Glomus Cervical Arteriovenous Malformation Presenting with Intracranial Subarachnoid Hemorrhage: Clinical Case and Pial Resection Surgical Technique Description.

Spinal intramedullary arteriovenous malformations (AVMs) can present with spinal hemorrhage. However, some of them occasionally can be the cause of angiographically negative intracranial subarachnoid hemorrhage, thus requiring a more comprehensive diagnostic approach to detect the possible source of bleeding. Nidal or arterial feeder aneurysms are widely considered high-risk rupture portions of the spinal AVM and recognized as a major cause of bleeding. Due to the tight eloquent confines within the thecal sac and the higher annual rupture risk after the initial bleeding, recurrent hemorrhage may have catastrophic outcomes. Hence the goal of management is to obliterate the spinal AVM preserving neurologic function and preventing future hemorrhagic events. Unlike cerebral AVMs, partial treatment of spinal intramedullary AVMs has been documented to be effective to improve the patients' prognosis dramatically. Microsurgical resection with or without adjuvant embolization has been considered the mainstay treatment for symptomatic glomus spinal intramedullary AVMs. The case of a 25-year-old man with acute cerebral subarachnoid hemorrhage caused by intranidal aneurysm rupture of cervical glomus-type AVM is presented here. The patient was surgically treated by C3-C4 laminectomy and AVM excision by pial resection technique. Thereby, the pial resection technique helps in providing subtotal AVM nidus resection, minimizing parenchymal dissection but effectively devascularizing glomus AVMs with satisfactory long-term results.

The usefulness of three-dimensional fusion imaging of spinal arteriovenous malformation by a workstation connected to angiography systems.

Digital subtraction angiography (DSA) is the most useful technique for diagnosing spinal arteriovenous malformations (AVM). In recent years, with the improvement of imaging capabilities, the usefulness of three-dimensional (3D) imaging by fusing various modalities has been recognized. The use of 3D fusion imaging with a workstation connected to an angiography system has been reported in many cases of intracranial disease, but less frequently for spinal AVM. In this article, we describe two illustrative cases of spinal AVM in which 3D fusion imaging was useful for treatment. Although 3D fusion images using the system have the disadvantage that only a maximum of two images can be fused, it provides spinal surgeons with useful information for preoperative evaluation in a small amount of time.