Spinal Digital Subtraction Angiography Research Articles

Localization of spinal dural arteriovenous fistulas from the spatial relationships of perimedullary vessels on standard MRI.

The goal in this study was to explore the spatial relationship of perimedullary vessels visualized on MRI to localize the side and the site of spinal dural arteriovenous fistula (SDAVF). A retrospective analysis of 30 consecutive patients diagnosed with SDAVF on MRI was undertaken. Two experienced reviewers blinded to all reports and angiographic images analyzed T2-weighted as well as postcontrast T1-weighted sequences. A focal prominent zone of perimedullary vessels with lateralization to one side in the thecal space was evaluated to locate the side and the site of the fistula. Spinal digital subtraction angiography served as the gold standard technique. Good interrater agreement (κ = 0.77) was shown for the diagnosis of SDAVF with perimedullary vessels on T2-weighted MRI. Flow voids on T2-weighted MRI demonstrated a sensitivity of 1.0 (95% CI 1.0-1.0) and an accuracy of 0.87 (95% CI 0.79-0.95) to identify the presence of fistula. The flow voids on T2-weighted MRI also demonstrated 0.88 (95% CI 0.71-1.03) sensitivity and 0.81 (95% CI 0.70-0.92) accuracy to identify the side of SDAVF. Furthermore, flow voids on T2-weighted MRI showed 0.87 (95% CI 0.71-1.03) sensitivity and 0.87 (95% CI 0.79-0.95) accuracy to identify the site of SDAVF within 3 vertebral levels above or below the actual site. Area under the receiver operating characteristic curve demonstrated significant results (0.87 [95% CI 0.73-1.0]; p < 0.001) for flow voids on T2-weighted MRI to identify the site of shunts within 3 vertebral levels in the cranial or caudal direction. Spatial distribution of perimedullary vessels observed on standard MRI show promise to locate the side and the site of fistula in patients with SDAVF.

Abstract Number ‐ 219: Spinal cord infarct in young: Fibrocartilaginous Embolism with Occlusion of Anterior Spinal Artery

Introduction Spinal cord infarctions are rare and account for fewer than 1% of all strokes. Diagnosis is usually established by clinical symptoms of sudden onset paraplegia and sensory dysfunction along with radiographic evidence of a non‐enhancing, diffusion‐restricted T2 hyperintense lesion on spinal cord MRI. We describe an interesting case of anterior spinal artery infarct from suspected fibrocartilaginous embolus from intervertebral disc. Methods Case report. Demographics and clinical history were obtained by chart review. MRI and cerebral angiogram images were reviewed and compared to radiology reports. Results 21‐year‐old female with no prior medical history presented with sudden onset headache, bilateral arm tingling, and neck stiffness that rapidly progressed within the hour to quadriplegia with numbness below the T2 sensory level. She continued to worsen, developed respiratory failure and required intubation. MRI of the cervical cord revealed a longitudinally extensive, non‐enhancing, diffusion‐restricted lesion extending from the bilateral medial medulla to the ventral spinal cord at C5/6 vertebral level. Cerebral and spinal digital subtraction angiography was notable for non‐opacification of the cervical anterior spinal artery. She had extensive work up for dissection, vasculitis, hypercoagulable state, autoimmune conditions that were all negative. However, there was a diminished T2 signal in her C5‐6 intervertebral disc with subtle loss of intervertebral disc space concerning for disc compression, likely related to her job requiring intensive heavy lifting. It was surmised that she developed a ventral cervical cord infarct secondary to fibrocartilaginous embolization and occlusion of anterior spinal artery, from recent mechanical compression of her C5‐6 disc. Cases of spinal cord infarcts following mechanical trigger, such as heavy lifting or falls, with histopathological confirmation of fibrocartilaginous material in the vasculature postmortem are well reported. It is postulated as a mechanism of spinal cord infarct in young patients that compressive forces on the intra‐vertebral body trigger embolization of nucleus pulposus material through persistent nuclear anastomoses to the spinal circulation. Conclusions Ischemic infarct should be considered in the differential diagnosis for sudden onset of symptoms localizable to spinal cord, especially when spinal MRI shows restricted diffusion in a vascular distribution. Demonstrating non‐opacification of the anterior spinal artery on digital subtraction angiography confirms the diagnosis. In case of negative work up for spinal cord infarct, the presence of an abnormal signal in the intervertebral disc on MRI may suggest fibrocartilaginous embolism as a mechanism of infarction in young patients.

Treatment of spontaneous spinal epidural hematoma in children: analysis of 25 cases.

Spontaneous spinal epidural hematoma (SSEH) is a rare neurosurgical emergency, presenting as sudden onset of back pain and weakness of lower extremities. Many patients have no definite cause. Some cases of SSEH caused by vascular malformation have been reported. The treatment strategy remains controversial. This study aimed to analyze the causes of SSEH and proposed a treatment strategy according to clinical outcomes of patients at a single institution. A total of 25 cases of SSEH under 18years of age treated between March 2004 and July 2021 were retrospectively analyzed. The mean age of the first SSEH onset was 7.1years. The most common location was cervicothorax. Nine patients suffered from multiple episodes. Twenty-three patients underwent spinal digital subtraction angiography (DSA), of which seven (30.4%) patients had positive findings: three cases had epidural artery venous fistula (AVF), two cases had epidural artery venous malformation (AVM), and two cases had abnormal concentration of contrast agent. Seventeen patients received surgery. Eleven patients (44%) were diagnosed as vascular malformation by either DSA or pathology. The follow-up rate was 80%, with 20 patients (80%) achieving satisfactory clinical outcome. Risk factors for poor clinical outcome included multiple episodes (p = 0.028) and higher Aminoff-Logue score (p = 0.005). Spinal epidural vascular malformation is a significant cause of SSEH. Spinal DSA is necessary. Surgery should be recommended for patients with multiple episodes, positive findings on DSA, or severe neurological deficits. Conservation therapy can be considered for other patients, but long-time follow-up is necessary.

Intraoperative Spinal Angiography during Microsurgical Occlusion of Spinal Dural Arteriovenous Fistula within the Hybrid Operation Room.

Spinal dural arteriovenous fistula (SDAVF) is a rare cause of progressive myelopathy in predominantly middle-aged men. Treatment modalities include surgical obliteration and endovascular embolization. In surgically treated cases, failure of obliteration is reported in up to 5%. The aim of this technical note is to present a safe procedure with complete SDAVF occlusion, verified by intraoperative digital subtraction angiography (DSA). We describe four patients with progressive leg weakness who underwent surgical obliteration of SDAVF with spinal intraoperative DSA in the prone position after cannulation of the popliteal artery. All surgeries took place in our hybrid operating room (OR) and were accompanied by electrophysiologic monitoring. Surgeries and cannulation of the popliteal artery were performed in the prone position. Ultrasound was used to guide the popliteal artery puncture. A 5-Fr sheath was inserted and the fistula was displayed using a 5-Fr spinal catheter. Spinal intraoperative DSA was performed prior to and after temporary clipping of the fistula point as well after the final SDAVF occlusion. The main feeder of the SDAVF fistula in the first patient arose from the right T11 segmental artery, which also supplied the artery of Adamkiewicz. The second patient initially underwent endovascular treatment and deteriorated 5 months later due to recanalization of the SDAVF via a small branch of the T12 segmental artery. The third and fourth cases were primarily scheduled for surgical occlusion. Access through the popliteal artery for spinal intraoperative DSA proved to be beneficial and safe in the hybrid OR setting, allowing the sheath to be left in place during the procedure. During exposure and after temporary and permanent occlusion of the fistulous point, intraoperative indocyanine green (ICG) video angiography was also performed. In one case, the addition of intraoperative DSA showed failure of fistula occlusion, which was not visible with ICG angiography, leading to repositioning of the clip. Complete fistula occlusion was documented in all cases. Spinal intraoperative DSA in the prone position is a feasible and safe intervention for rapid localization and confirmation of surgical SDAVF occlusion.

The Accuracy of the TRICKS MRI in Diagnosing and Localizing a Spinal Dural Arteriovenous Fistula: A Feasibility Study

Spinal vascular malformations (SVMs) are a heterogenous group of vascular abnormalities. The gold standard for diagnosis of SVMs is spinal digital subtraction angiography (DSA), which can be challenging because of the large number of segmental arteries that need to be catheterized and the limitations in term of contrast volume used and fluoroscopy time. We describe and compare the use of the time-resolved imaging of contrast kinetics (TRICKS) sequence and DSA in the diagnosis of spinal dural arteriovenous fistulas (SDAVFs) in our institution. This is a retrospective cohort study of 27 patients who had a TRICKS MRI followed by a DSA for the diagnosis of their SDAVFs between November 2003 and November2021. A total of 19 (70.4%) patients were positive for a SDAVF on both TRICKS MRI and DSA. Out of those 19, 9 (47.4%) were in the exact location on both TRICKS MRI and DSA whereas 10 (52.6%) were in different locations. With respect to the 10 patients who had discrepancies in their SDAVF localization between the 2 modalities, 9 (90%) patients had a 1-level difference and 1 (10%) had a 2-level difference. TRICKS MRI represents an accurate screening tool to be performed before a spinal DSA in order to guide the interventionalist to focus on the correct level ±2 levels; this extra noninvasive screening tool will decrease the risk of a kidney injury from an overuse of contrast and minimize the fluoroscopy/radiation overexposure.

Key of Classification and Diagnosis of Spinal Arteriovenous Malformation

Spinal arteriovenous malformation(AVM)is a rare disease in which blood is received from the spinal feeding arteries. Owing to its rarity, there is limited experience regarding its diagnosis and treatment. In addition, the various classifications that have been proposed historically make it more difficult for the young neurosurgeons to understand this disease. Because delayed initial diagnosis leads to irreversible damage of the spinal cord, neurosurgeons should always consider spinal AVM as one of the differential diagnoses. In order to understand the pathological condition of spinal AVM, it is important to learn basic classification. Spinal AVM is classified as intradural, dural, and epidural. Spinal digital subtraction angiography(DSA)is the gold-standard for the diagnosis of spinal AVM and is indispensable toolfor treatment planning. The purpose of this paper is to summarize a basic classification and diagnosis of spinal AVM.

The Relevance of Preoperative Identification of the Adamkiewicz Artery in Posterior Mediastinal Pediatric Tumors

BackgroundInjury to the artery of Adamkiewicz (AKA) during surgery may lead to spinal cord ischemia and severe neurologic complications. Posterior mediastinal tumors may be adjacent to AKA, but data on preoperative visualization of AKA in children are rare. This study analyzed the importance of identifying the AKA preoperatively by spinal digital subtraction angiography (DSA) in children with posterior mediastinal tumors for therapeutic procedure.MethodsBetween 2002 and 2021, 36 children with posterior mediastinal tumors were evaluated for surgery at the authors’ clinic. In 10 children with left-sided or bilateral tumor located at vertebral levels T8 to L1, spinal DSA was performed during preoperative workup to assess AKA. The patient and tumor characteristics as well as the diagnostic and therapeutic procedures were analyzed.ResultsThe median age of the 10 children at examination was 69 months (range, 16–217 months). Three of the children were younger than 2 years. The tumor entities were neuroblastoma, ganglioneuroblastoma, ganglioneuroma, local relapse of a hepatocellular carcinoma, and neurofibroma. The AKA was identified in all cases, and proximity to the tumor was detected in four patients, three of whom had their planned surgery changed to irradiation. No complications occurred during spinal DSA or surgery.ConclusionsIn posterior mediastinal pediatric tumors, spinal DSA is a safe and reliable method for preoperative visualization of the AKA. It can show proximity to the tumor and guide the local therapy, thereby avoiding critical intra- and postoperative situations.

Four-dimensional digital subtraction angiography for exploration of spinal cord vascular malformations: preliminary experience

BackgroundThe precise understanding of the angioarchitecture of spinal vascular malformations (SVMs) is often difficult to reach with conventional digital subtraction angiography (DSA). The purpose of our study was to evaluate...

Removal of Antiscatter Grids for Spinal Digital Subtraction Angiography: Dose Reduction without Loss of Diagnostic Value.

Background Spinal digital subtraction angiography (DSA) exposes patients and operators to substantial amounts of radiation. Antiscatter grid (ASG) removal is used to decrease radiation exposure but may reduce image quality. Purpose To determine whether ASG removal during spinal DSA in adults reduces radiation dose while maintaining diagnostic image quality and whether dose reduction is related to body mass index (BMI). Materials and Methods This Health Insurance Portability and Accountability Act-compliant prospective study included adults undergoing spinal DSA between January and December 2016. Each procedure included an additional angiographic acquisition performed twice, once with and once without ASG, either documenting the artery of Adamkiewicz (no pathology group) or the condition leading to the procedure (pathology group). Dose differences between study acquisitions and the influence of BMI were evaluated via paired t test. Two neurointerventionalists blinded to acquisition protocols were asked to independently evaluate a sample of 40 study acquisitions (20 with ASG, 20 without ASG) from 20 randomly selected participants to (a) rate image quality, (b) categorize findings, and (c) determine whether images had been obtained with or without ASG. Percentage agreement on image quality, findings categorization, and ability to correctly identify the acquisition protocol was calculated for both readers. Results Fifty-three participants (mean age ± standard deviation, 51 years ± 15.2; 32 men) were evaluated. ASG removal reduced the mean dose per acquisition by approximately 33% (mean dose-area product and air kerma decreased from 202 to 135.6 µGy/m2 and from 35.3 to 24 mGy, respectively; P < .001) independently of BMI (P = .3). Both readers evaluated all images (40 of 40) as being of diagnostic quality and correctly categorized findings in 19 of 20 (95%) cases. Overall percentage agreement for correct protocol identification was 60% (12 of 20) for grid-in and 45% (nine of 20) for grid-out images. Conclusion Antiscatter grid removal during spinal digital subtraction angiography decreased participants' radiation exposure while preserving diagnostic image quality. © RSNA, 2020.

Advances in 3D angiography for spinal vascular malformations

Spinal vascular malformations are difficult to diagnose lesions that can be associated with significant permanent morbidity. The angioarchitecture of spinal vascular anatomy and the associated pathologies have only recently been illuminated by the advent of spinal angiography. However, conventional spinal digital subtraction angiography is often limited by significant variability, overlapping vessels, as well as an inability to understand the precise location of the nidus or fistula in relation to the spinal cord and spine. In this study, we present 4 unique cases wherein 3-dimensional rotational angiography (3DRA) with dual volume acquisition was useful in defining the anatomy of spinal fistulas as well as planning treatment.

Diagnostic accuracy and efficiency of combined acquisition of low-dose time-resolved and single-phase high-resolution contrast-enhanced magnetic resonance angiography in a single session for pre-angiographic evaluation of spinal vascular disease.

Background/PurposeThe purpose of this study was to evaluate the utility and efficacy of combined low-dose, time-resolved (TR) and single-phase high-resolution (HR) contrast-enhanced MRA (CE-MRA) as a pre-angiographic study for spinal vascular disease.Materials and methodsSeventeen consecutive patients with suspected spinal vascular disease were retrospectively reviewed. All patients underwent combined low-dose TR CE-MRA and three-dimensional single-phase HR CE-MRA at 3 Tesla, followed by conventional spinal digital subtraction angiography (DSA) within 90 days. Six patients underwent additional spinal MRA and DSA for treatment follow-up. Spinal lesions were analyzed in terms of presence, disease type, laterality, spinal level, and number of arterial feeders.ResultsLow-dose TR CE-MRA helped proper localization of subsequent HR CE-MRA in two patients with high or low level of the lesion. For initial detection of spinal vascular disease, sensitivity, specificity and accuracy of CE-MRA were 93.3% (n = 14/15), 100% (n = 3/3), and 94.4% (n = 17/18), respectively. In characterization of dural arteriovenous fistula (AVF), perimedullary AVF, spinal cord arteriovenous malformation (AVM), and extraspinal AVM, CE-MRA correctly characterized in 86.7% (n = 13/15) among the positive findings, and in 88.9% (n = 16/18) among the several patients including negative results. CE-MRA showed matched per-case localization of arterial feeders within 1 vertebral level in 80% (n = 12/15), and matched per-lesion localization in 78.3% (n = 18/23).ConclusionCombined low-dose TR CE-MRA and single-phase HR CE-MRA at 3 Tesla was an effective and accurate non-invasive tool for the pre-angiographic evaluation of spinal vascular diseases in a single session.

Spinal dural arteriovenous fistula: delay to radiological diagnosis and sources of radiological error

To highlight the magnetic resonance imaging (MRI) signs associated with spinal dural arteriovenous fistula (SDAVF) through categorisation of sources of radiological error and investigation of the delay to radiological diagnosis. This was a retrospective, observational study of cases referred to a neuroscience centre over 11 years. All patients who underwent spinal digital subtraction angiography (DSA) with a subsequent diagnosis of SDAVF were identified. Prior imaging was reviewed and compared with the formal reports issued. Thirty-seven patients with SDAVF were initially imaged in seven institutions. Radiological abnormalities including intradural vessels (37/37, 100%), cord T2 signal change (34/37, 91.9%), and cord expansion (26/37, 70.2%) were present on prior MRI. These signs were not recognised in 22/37 (59.5%), 7/34 (20.5%), and 15/26 (57.7%) of cases, respectively. Increased T2 signal in the cord was the most commonly identified sign (27/34; 79.4%), but prompted either no diagnosis (7/34; 20.5%) or differential diagnoses including ischaemic, inflammatory, or neoplastic aetiologies or a syrinx in 11/34 (32.4%). An appropriate diagnosis was made on initial MRI in 15 patients (40.5%). The time from initial imaging to diagnosis was significantly delayed for those patients who did not have an arteriovenous vascular aetiology included in the initial differential diagnosis (281 (423.3) days versus 22 (15.7) days, p=0.03). SDAVF have imaging features that are frequently missed or misinterpreted. This results in a significant delay to definitive diagnosis and therefore treatment.

Diagnosis of spinal dural arteriovenous fistula using 3D T2-weighted imaging.

To evaluate spinal MRIs without and with 3D T2W imaging among patients without and with spinal dural arteriovenous fistula (SDAVF) confirmed by spinal digital subtraction angiography (DSA). A retrospective case-control study was performed among patients without and with SDAVF who had both spinal MRIs and gold standard spinal DSA. Two neuroradiologists independently reviewed spinal MRIs that were performed with either sagittal T2W turbo spin echo (2D group) or sagittal 3D T2W sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) (3D group) and documented the presence or absence of SDAVF. Using spinal DSA diagnosis as a gold standard, the sensitivity, specificity, and interobserver agreement for the 2D-group and 3D-group MRI diagnosis were calculated. The 2D group consisted of 21 patients and the 3D group consisted of 16 patients. For both radiologists, the 2D group demonstrated a sensitivity of 100% and specificity of 100%. Interobserver agreement in the 2D group was perfect (k=1.0). For both radiologists, the 3D group demonstrated sensitivity of 100.0% and specificity of 92.3%. Interobserver agreement in the 3D group was perfect (k=1.0). While flow voids were considered more conspicuous, spinal cord signal abnormality was considered less conspicuous with 3D T2W SPACE compared with conventional 2D STIR sequence. 3D T2W SPACE should be used in conjunction with 2D T2W sequences to more accurately detect abnormal cord signal and determine when perimedullary flow voids are pathologically abnormal for the radiologic diagnosis of SDAVF.

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

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 ofSEDAVFs that is featured with a unique drainage pattern and present our natural history hypothesis of SEDAVFs. Five SEDAVF cases of the new type werereviewed retrospectively from a high case-volume spinal vascular malformation database. The clinical manifestations, neuroradiologic findings, angioarchitecture, treatment strategies, and clinical outcomes were assessed. 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. 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.

Application of hybrid operating room in the treatment of spinal dural arteriovenous fistulas

Objective: To explore the experience in the treatment of spinal dural arteriovenous fistulas with application of hybrid operating room. Method: A retrospective analysis was performed among 22 patients with spinal dural arteriovenous fistulas admitted to Department of Neurosurgery of Tianjin Medical University General Hospital who received operation in the hybrid operating room from March 2011 to February 2016. Modified Aminoff-Logue scores (ALS) for myelopathy was used to evaluate the spinal function.All the 22 patients were followed up 6-12 months after the operation. Result: All the patients were diagnosed by spinal digital subtraction angiography (DSA). The modified ALS pre-operation and post-operation 6 months were (4.7±1.8) and (2.0±1.5), respectively, with significant difference (P<0.01). There were 15 cases with mild dysfunction, 6 cases with moderate dysfunction, severe dysfunction in 1 case before operation.Fifteen cases were cured, 4 cases improved, 1 case had no change after 6 months follow-up.The improvement rate was 95.45%. Conclusion: The application of hybrid operating room in the treatment of spinal dural arteriovenous fistulas achieves good outcome and provides a convenient and effective approach, which embodies the idea of precision medicine.

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

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. Fifty-five cases of SSEH treated at our institutions between February 2002 and February 2016 were retrospectively analyzed. 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). 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.

Dynamic contrast-enhanced magnetic resonance angiography for the localization of spinal dural arteriovenous fistulas at 3T

This study was undertaken to evaluate the accuracy of dynamic contrast-enhanced magnetic resonance angiography (DCE-MRA) in the precise location and demonstration of fistulous points in spinal dural arteriovenous fistulas (SDAVFs). Fifteen patients (14men, 1woman; age range: 40-78years; mean: 55.5years) harboring SDAVF who underwent preoperative DCE-MRA and spinal digital subtraction angiography (DSA) between January2012 and January2015 were evaluated retrospectively. Two reviewers independently evaluated the level and side of the arteriovenous fistula and feeding artery on 3T DCE-MRA and DSA images. The accuracy of DCE-MRA was assessed by comparing its findings with those from DSA and surgery in each case. All 15patients underwent DCE-MRA and DSA. DSA was unsuccessful in two patients due to technical difficulties. All cases were explored surgically, guided by the DCE-MRA. Surgery confirmed that 14AVF sites were located in the thoracic spine, 5 in the lumbar spine, and 1 in the cervical spine. The origin of the fistulas and feeding arteries was accurately shown by DCE-MRA in 11 of the 15patients. DCE-MRA also detected dilated perimedullary veins in all 15patients. Overall, DCE-MRA facilitated DSA catheterization in 10cases. In six patients, the artery of Adamkiewicz could be observed. In 15 out of 20fistulas (75%), both readers agreed on the location on DCE-MRA images, and the κ coefficient of the interobserver agreement was 0.67 (95% confidence interval [CI], 0.16-0.87). In 13 of 16shunts (75%), the DCE-MRA consensus findings and DSA findings coincided. The intermodality agreement was 0.77 (95% CI: 0.35-0.92). Our DCE-MRA studies benefited from the use of a high-field 3T MR imaging unit and reliably detected and localized the SDAVF and feeding arteries. As experience with this technique grows, it may be possible to replace DSA with DCE-MRA if surgery is the planned treatment.

Intraoperative spinal digital subtraction angiography: indications, technique, safety, and clinical impact

BackgroundCerebral intraoperative DSA (IODSA) is a well-described, routinely performed procedure that allows the effectiveness of cerebrovascular interventions to be evaluated in the operating room. Spinal IODSA, on the other hand,...

P.119 Minimally invasive surgical disconnection of a spinal dural arteriovenous fistula with the use of intraoperative digital subtraction angiography

Background: Spinal dural arteriovenous fistulas (dAVF) are a significant but treatable cause of progressive myelopathy. The goal of treatment is disconnection of the fistula, which is often accomplished through an open surgical approach. We report two cases using a minimally invasive surgical (MIS) approach for dAVF ligation with intraoperative digital subtraction angiography (DSA) to confirm occlusion. Methods: Case report. Results: Two patients presented with progressive thoracic myelopathy and were identified to have fistulous connections at the left L1 and T8 levels respectively. Intraoperatively, a left femoral puncture was performed and a 5-French (40 cm) sheath was inserted. Patients were positioned prone and intraoperative spinal DSA was performed using the Siemens Zeego. Once the feeding radicular artery was visualized, image overlay and cross-hair laser was used to trace and localize the fistulous zone. A unilateral single level MIS hemi-laminectomy was performed. The fistulous zone and accompanying nerve root were exposed and small hemostatic clips were applied followed by surgically disconnection. Finally, intraoperatively video angiography as well as spinal DSA were performed for confirmation. Conclusions: MIS disconnection with intraoperative DSA is a safe and effective technique for treating spinal dAVFs. Patients benefit from quicker recovery and shorter hospital stay.

E-008 imaging workup for angiographically negative subarachnoid hemorrhage: how much is life worth?

Introduction At presentation, the source of subarachnoid hemorrhage is cryptogenic in approximately 15% of cases. In such cases, while perimesencephalic hemorrhages have a low rate of morbidity and mortality, non-perimesencaphic patterns of hemorrhage may portend other bleeding sources; in some reports as high as 16%. Diagnostic work-up after negative catheter angiography in the latter patients typically includes magnetic resonance imaging of the brain and cervical spine for arteriovenous malformations and fistulae, as well as repeat angiography at a delayed date to look for vascular lesions that may have become visible in the interim such as previously thrombosed aneurysms or vascular malformations that are tamponaded by hemorrhage. Methods Case Series. Results Three patients (males – 2, median age – 25) presented with headaches and on imaging were found to have intracranial subarachnoid hemorrhage (SAH). Initial work-up for etiology of SAH was negative which included cerebral digital subtraction angiography (DSA) and MRI of the brain. All three patients also had lower back and lower extremity radicular pain, for which further investigations were performed. MRI of the spine revealed thoraco-lumbar aterio-venous malformation (AVM). Spinal DSA confirmed the findings, with the one of the patient’s AVM nidus from T12 to L2 vertebral body, while the other had a nidus at L1 vetebral body and the third had the nidus at T12 vertebral body. We suspect the thoraco-lumbar AVM as the etiology of SAH in these three unique cases. Conclusion Already, the cost effectiveness of routine cervical imaging in angiographically negative subarachnoid hemorrhage is often debated due to low yield; the causative lesions in these three patients would not have been identified using standard imaging protocols and were only discovered after imaging of the lower thoracic and lumbar spine. While the cost effectiveness of routine imaging of the spine in these patients is debatable, these cases show that thoraco-lumbar arteriovenous malformations can rarely present with headache and subarachnoid hemorrhage, and judicious use of whole spine imaging should be considered in these patients. Disclosures R. Cerejo: None. M. Grabowski: None. S. John: None. A. Bauer: None. B. Chaudhry: None. M. Bain: None. G. Toth: None. F. Hui: None.