Spinal dural arteriovenous fistulas

'Pressure cooker' and 'balloon pressure' techniques significantly increase 3-month complete occlusion rate after spinal arteriovenous fistula embolization as compared to glue: single center evaluation on 38 consecutive patients

BACKGROUND

Spinal arteriovenous fistulas can be treated either by surgery or by endovascular means, using different strategies. The main drawback of embolization is the risk of recurrence. Our objective is to evaluate the angiographic occlusion rate and the predictive factors of angiographic cure of spinal arteriovenous fistulas at 3 months or more after embolization.

METHODS

This is a retrospective single-center study including 38 consecutive patients with spinal arteriovenous fistulas treated by embolization as first-line treatment. We reviewed clinical and imaging data, complications, and the immediate angiographic occlusion rate of the fistulas, and at 3 months or more after the embolization.

RESULTS

A total of 45 embolization procedures were performed: 30 procedures using glue, 15 using Onyx by 'pressure cooker' or 'balloon pressure' techniques. We observed no statistically significant difference between the two groups concerning the immediate angiographic occlusion rate (87% in both groups; P>0.9), as well as for periprocedural complication rates. The angiographic occlusion rate at 3 months or more was higher in the Onyx 'combined' techniques treated group (87% vs 40%, P=0.007). The use of Onyx 'combined' techniques was independently associated with angiographic cure at 3 months after embolization (P=0.029). No other factors were identified as predictive of angiographic cure and clinical recovery after embolization procedures, nor were any predictive factors identified for the occurrence of periprocedural complications.

CONCLUSION

Embolization of spinal arteriovenous fistulas with Onyx using 'combined' techniques appears to be safe and associated with a higher rate of angiographic occlusion at 3 months than regular embolization with glue.

Routine MR Imaging Protocol and Standardization in Central Nervous System Demyelinating Diseases

Standardized MR imaging protocols are important for the diagnosis and monitoring of patients with multiple sclerosis (MS) and the appropriate use of MR imaging in routine clinical practice. Advances in using MR imaging to establish an earlier diagnosis of MS, safety concerns regarding intravenous gadolinium-based contrast agents, and the value of spinal cord MR imaging for diagnostic, prognostic, and monitoring purposes suggest a changing role of MR imaging for the management and care of MS patients. The MR imaging protocol emphasizes 3 dimensional acquisitions for optimal comparison over time.

The hybrid operation based on microsurgery assisted by intraoperative spinal angiography in patients with spinal dural arteriovenous fistula: a series of 45 cases from multicenter research

BACKGROUND

To assess the clinical effects of hybrid surgery, which includes spinal angiography-assisted microsurgery, in the treatment of spinal dural arteriovenous fistulas (SDAVF).

METHODS

We retrospectively reviewed 45 patients who underwent hybrid Spinal dural arteriovenous fistula (SDAVF) resection between September 2019 and June 2022. The hybrid surgery involved intraoperative digital subtraction angiography (DSA) of the spinal vessels to determine the source of the blood-supplying artery, location of the fistula and draining vein, indocyanine green fluorescence (ICG)-assisted microsurgical resection of the fistula, and postoperative DSA to verify therapeutic efficacy. The Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Visual Analog Scale (VAS), Barthel score, modified Rankin Scale (mRS) and modified Aminoff-Logue score (key indicator) were used to assess the clinical effects of SDAVF resection.

RESULTS

A series of 45 patients with SDAVF were successfully treated with hybrid surgery without fistula recurrence. There were no intraoperative complications related to spinal angiography, and none of the patients died. Postoperatively, two patients experienced clinical deterioration of spinal cord function, which manifested as bilateral lower extremity paralysis and bladder sphincter dysfunction. Postoperatively, improvement in mALS scores was observed in 16 cases (35.6%) within 1-2 days, 12 cases (26.7%) at 1 week, and 7 cases (15.6%) at 6 months. No SDAVF recurrence was detected in the spinal MRA examination 6 months after surgery. When compared with preoperative mALS scores, 35 cases (77.8%) showed significant improvement in symptoms, 8 cases (17.8%), remained unchanged, and 2 cases (4.4%) deteriorated. Compared with the preoperative scores, the postoperative mALS score was significantly decreased [postoperative vs. preoperative: 2(1,3) vs. 3(2,4)], HAMD score [(12.2 ± 5.5) vs. (19.6 ± 6.3)], HAMA score [(15.6 ± 5.5) vs. (20.5 ± 6.5)], and VAS score [3(2,5) vs. 5(4,8)]. Conversely, Barthel scoresshowed significant increase [(74.6 ± 8.7) vs. (67.8 ± 9.2)] (P < 0.05). However, the mRS scores were lower than preoperatively [1(1,2) vs. 2(1,2.5)], but the difference was not statistically significant (P > 0.05). There was a significant increase in "good" neurological outcomes at follow-up compared with preoperative function (62.2% vs. 33.3%) (P = 0.023).

CONCLUSION

Hybrid surgery is a safe and effective treatment for patients with SAVF, which is beneficial for improving anxiety, depression, spinal cord, and neurological function, and relieving pain. However, the treatment of patients with SDAVF is a complex, long-term process requiring further multidisciplinary interventions, including clinical care, psychosocial interventions, and neurorehabilitation.

Specific electromyography characteristics can distinguish longitudinally extensive transverse myelitis from congestive myelopathy due to spinal dural arteriovenous fistula: a retrospective study

Aims/Background Although electromyography has been extensively used in the diagnosis of neurological diseases, there is no comprehensive understanding of the electromyography manifestations of spinal dural arteriovenous fistula. Given the widespread use of electromyography in the diagnosis of neurological conditions, it is worthwhile to holistically analyse the electromyography findings of spinal dural arteriovenous fistula to differentiate it from neurological diseases that share similar clinical manifestations. The aim of this study is to evaluate whether electromyography can distinguish spinal dural arteriovenous fistula from longitudinally extensive transverse myelitis. Methods We holistically reviewed files of all patients who were diagnosed with spinal dural arteriovenous fistula or longitudinally extensive transverse myelitis at The First Medical Centre of PLA General Hospital from 1 January 2010 to 31 December 2020. We compared the symptomology, epidemiology, and imaging results of patients with spinal dural arteriovenous fistula and longitudinally extensive transverse myelitis, placing emphasis on their electromyography manifestations. Student's t test was used to analyse normally distributed data, while Chi-square test was used to compare classification statistics. Results Lesions of spinal dural arteriovenous fistula shown on images tend to appear at lower lumbar and sacral segments, whereas lesions of the cervical and upper thoracic segments are more characteristic of longitudinally extensive transverse myelitis. Spinal dural arteriovenous fistula patients and longitudinally extensive transverse myelitis patients overlap in terms of clinical manifestations. After comparison, the two groups of patients had different demographics (age, sex), onset mode, predisposing factors before onset, and electromyographic features. The electromyographic features of patients with spinal dural arteriovenous fistula were associated with neurogenic damage (p < 0.001). Conclusions In patients with spinal dural arteriovenous fistula, electromyography can help clinicians to identify early disease, avoid patient treatment delay, and eliminate unnecessary treatment.

Spinal dural and epidural fistulas: role of cone beam CT in diagnosis and treatment

Understanding normal spinal arterial and venous anatomy, and spinal vascular disease, is impossible without flow-based methods. Development of practical spinal angiography led to site-specific categorization of spinal vascular conditions, defined by the 'seat of disease' in relation to the cord and its covers. This enabled identification of targets for highly successful surgical and endovascular treatments, and guided interpretation of later cross-sectional imaging.Spinal dural and epidural arteriovenous fistulas represent the most common types of spinal shunts. Although etiology is debated, anatomy provides excellent pathophysiologic correlation. A spectrum of fistulas, from foramen magnum to the sacrum, is now well-characterized.Most recently, use of cone beam CT angiography has yielded new insights into normal and pathologic anatomy, including venous outflow. It provides unrivaled visualization of the fistula and its relationship with spinal cord vessels, and is the first practical method to study normal and pathologic spinal veins in vivo-with multiple implications for both safety and efficacy of treatments. We advocate consistent use of cone beam CT imaging in modern spinal fistula evaluation.The role of open surgery is likely to remain undiminished, with increasing availability and use of hybrid operating rooms for practical intraoperative angiography enhancing safety and efficacy of complex surgery.

Extravertebral low back pain: a scoping review

BACKGROUND

Low back pain (LBP) is one of the most common reasons for consultation in general practice. Currently, LBP is categorised into specific and non-specific causes. However, extravertebral causes, such as abdominal aortic aneurysm or pancreatitis, are not being considered.

METHODS

A systematic literature search was performed across MEDLINE, Embase, and the Cochrane library, complemented by a handsearch. Studies conducted between 1 January 2001 and 31 December 2020, where LBP was the main symptom, were included.

RESULTS

The literature search identified 6040 studies, from which duplicates were removed, leaving 4105 studies for title and abstract screening. Subsequently, 265 publications were selected for inclusion, with an additional 197 publications identified through the handsearch. The majority of the studies were case reports and case series, predominantly originating from specialised care settings. A clear distinction between vertebral or rare causes of LBP was not always possible. A range of diseases were identified as potential extravertebral causes of LBP, encompassing gynaecological, urological, vascular, systemic, and gastrointestinal diseases. Notably, guidelines exhibited inconsistencies in addressing extravertebral causes.

DISCUSSION

Prior to this review, there has been no systematic investigation into extravertebral causes of LBP. Although these causes are rare, the absence of robust and reliable epidemiological data hinders a comprehensive understanding, as well as the lack of standardised protocols, which contributes to a lack of accurate description of indicative symptoms. While there are certain disease-specific characteristics, such as non-mechanical or cyclical LBP, and atypical accompanying symptoms like fever, abdominal pain, or leg swelling, that may suggest extravertebral causes, it is important to recognise that these features are not universally present in every patient.

CONCLUSION

The differential diagnosis of extravertebral LBP is extensive with relatively low prevalence rates dependent on the clinical setting. Clinicians should maintain a high index of suspicion for extravertebral aetiologies, especially in patients presenting with atypical accompanying symptoms.

Spontaneous thrombosis of high flow pediatric arteriovenous fistulae: Case series of two patients and a comprehensive literature review

Pediatric pial arteriovenous shunts in the brain and spine are challenging to understand because of low incidence, variable presentation, and associations with genetic syndromes. What is known about their natural history comes from reviews of small series. To better understand the natural history and role for intervention, two cases are presented followed by a review of the literature. In the first case, an infant with a prior history of intracranial hemorrhage from a ruptured pial fistula returns for elective embolization for a second pial fistula which was found to be spontaneously thrombosed 2 weeks later. In the second case, a 5-year-old with a vertebro-vertebral fistula, identified on work up for a heart murmur and documented with diagnostic angiography, is brought for elective embolization 6 weeks later where spontaneous thrombosis is identified. In reviewing the literature on pediatric single-hole fistulae of the brain and spine, the authors offer some morphologic considerations for identifying which high-flow fistulae may undergo spontaneous thrombosis to decrease the potentially unnecessary risk associated with interventions in small children.

Surgical treatment of marginal sinus dural arteriovenous fistula: a narrative review

BACKGROUND

Dural arteriovenous fistulas of the marginal sinus (DAVFms) are uncommon and complex, with varied symptoms. Their complexity is heightened by the region's dense anastomotic network, posing risks for endovascular treatment. Surgical intervention can be effective, but this depends on thorough pre-operative understanding and optimal intra-operative visualization of the fistula.

OBJECTIVE

To review the relevant anatomy, presentation patterns of DAVFms, and provide insights for surgical treatment.

METHODS

Recent literature on DAVFms was reviewed, and three surgical cases are discussed to highlight treatment principles.

RESULTS

The symptoms of a DAVFms vary depending on its venous drainage pattern. Drainage may be either ascending towards the cranial compartment or descending towards the spinal canal. Patients suffering from DAVFms may experience hemorrhage, particularly when venous drainage is directed upwards. Congestive symptoms of the spinal cord or brainstem can occur in cases of downward venous drainage. Compared to the endovascular approach, open surgery has a higher success rate in obliterating the fistula and yields better outcomes in cases of perimedullary venous drainage. Achieving surgical success necessitates thorough preoperative evaluation and adequate surgical exposure. Brainstem hyperintensity observed on T2-weighted MRI scans is linked to a poorer prognosis for recovery.

CONCLUSION

Treating complex DAVFms often requires surgery, as endovascular methods may not be feasible. Successful surgery hinges on a precise understanding of the fistula's venous architecture and its spatial relationships, assessed using digital substraction angiography (DSA), angio-MRI, and angio-CT. Optimal intraoperative exposure is crucial for effective surgery.

Clinical presentation and treatment of 26 spinal epidural arteriovenous fistulas: a single-center experience

BACKGROUND

Spinal epidural arteriovenous fistulas (SEDAVFs) are rarely diagnosed vascular malformations that can cause spinal cord compression and congestive myelopathy.

METHODS

This is a single-center, retrospective case series of patients with SEDAVFs who underwent observation or treatment at UCLA medical center between 1993 and 2023.

RESULTS

Between 1993 and 2023 a total of 26 patients at UCLA were found to have a SEDAVF. The median age at treatment was 59 years (range 4 months to 91 years). Compared with sacral, lumbar, and thoracic SEDAVFs, patients with cervical SEDAVF were younger (41 years vs 63 years, P=0.016) and more likely to be female (66.7% vs 14.3%, P=0.006). Possible triggers for development of SEDAVFs may be prior spinal surgery or trauma (n=4), turning the neck (n=1), lifting a heavy box (n=1), a prolonged period of bending over (n=1), and neurofibromatosis type 1 (n=1). Of the 22 patients treated endovascularly, 18 (82%) were angiographically cured on the first attempt without complications. One patient underwent surgical treatment alone and had a failed surgery on the first attempt, and developed a surgical site infection after the second successful attempt at treatment. Of the 16 patients with adequate clinical follow-up, 11 (69%) demonstrated early improved clinical outcome (eg, improved strength on examination, absent bruit).

CONCLUSIONS

SEDAVFs are a rarely diagnosed disease that can be treated effectively and safely with endovascular embolization in most cases. Patients with sacral, lumbar, and thoracic SEDAVFs were older and more often male compared to patients with cervical SEDAVFs.

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.

Functional Anatomy of the Spinal Cord

Localization of lesions in the spinal cord requires knowledge of the functional anatomy of gray and white matter tracts. Using decussation points for white matter tracts can help determine lesion level. Pathologies can affect gray and white matter tracts in distinct ways and pattern recognition can help narrow down the differential diagnosis.

Vascular Myelopathies

OBJECTIVE

Vascular injuries of the spinal cord are less common than those involving the brain; however, they can be equally devastating. This article discusses the diagnosis and management of ischemic and hemorrhagic vascular disorders of the spinal cord.

LATEST DEVELOPMENTS

Clinical suspicion remains the mainstay for recognizing vascular myelopathies, yet diagnoses are often delayed and challenging in part because of their rarity and atypical manifestations. Noninvasive imaging such as CT and MRI continues to improve in spatial resolution and diagnostic precision; however, catheter-based spinal angiography remains the gold standard for defining the spinal angioarchitecture. In addition to hemorrhagic and ischemic disease, the contribution of venous dysfunction is increasingly appreciated and informs treatment strategies in conditions such as intracranial hypotension.

ESSENTIAL POINTS

Vascular disorders of the spine manifest in variable and often atypical ways, which may lead to delayed diagnosis. Increased awareness of these conditions is critical for early recognition and treatment. The goal of treatment is to minimize long-term morbidity and mortality.

Spinal dural arteriovenous fistula: a comprehensive review of the history, classification systems, management, and prognosis

Spinal dural arteriovenous fistulas account for the majority of spinal vascular malformations. They are typically located in the thoracolumbar region and are diagnosed in the middle-aged and elderly populations. Although spinal dural arteriovenous fistulas have been postulated to be acquired, their exact development remains uncertain. Typically, the arteriovenous shunt is situated close to the spinal nerve root, inside the dura mater, where the blood from the radiculomeningeal artery and radicular vein intermix. Throughout history, there have been multiple classification systems of spinal arteriovenous shunts since 1967. Those were mainly based on the evolution of diagnostic studies as well as the treatment of these lesions. Such classification systems have undergone significant changes over the years. Unlike intracranial dural arteriovenous fistula, spinal dural arteriovenous fistula is progressive in nature. The neurological manifestations, due to venous congestion, tend to be insidious as well as non-specific. These include sensory deficits, such as paresthesia, bilateral and/or unilateral radicular pain affecting the lower limbs, and gait disturbances. Spinal dural arteriovenous fistulas can be suspected on magnetic resonance imaging/magnetic resonance angiography and confirmed by digital subtraction angiography (DSA). The management includes surgery, endovascular therapy, and in selected cases, radiotherapy. The treatment goal of spinal dural arteriovenous fistula is to halt the progression of the disease. The prognosis depends on both the duration of symptoms as well as the clinical condition prior to therapy. The present article comprehensively reviews the pathophysiology, changes in classification systems, natural history, clinical manifestations, radiological features, management, and prognosis.

Spinal dural arteriovenous fistula in a child: a rare presentation

Spinal dural arteriovenous fistula (AVF) is an abnormal shunting between the segmental artery and radicular vein adjacent to the dural root sleeve in the spine. This is the most common vascular malformation of the spinal cord and is a rare but treatable cause of para or quadriplegia. It most commonly occurs in elderly men and often affects the thoracolumbar region. These patients clinically present with progressive myelopathies, and other autonomic symptoms (e.g., bladder and bowel dysfunction) subsequently in the later course of the disease. Computed tomography angiography and magnetic resonance imaging remain the modality for initial evaluation. Herein, we present a rare case of spinal dural AVF in a child along with a review of imaging modalities. To the best of our knowledge, there are few case reports of this condition in a paediatric age group.

Things are not what they seem neurologically and radiologically: An apt descriptor for spinal dural arteriovenous fistula (SDAVF)

Spinal dural arteriovenous fistulas (SDAVF) are the most common vascular malformations affecting the spinal cord. It is infrequently encountered in clinical practice and is believed to be acquired, predominantly affecting middle-aged and elderly men with unknown etiology. It is usually misdiagnosed despite presenting with conventional clinical findings and radiological features. Insidious onset of myelopathic findings is seen in addition to pathognomonic findings of cord edema and intrathecal flow voids on MRI. We present a case of SDAVF that was missed by the treating orthopedic surgeon and underwent spinal decompression with subsequent persistence of myelopathic symptoms. Angiography is required to confirm the diagnosis location of the fistula. Treatment is with embolization using liquid embolic agents or surgical through ligation of the draining vein. Endovascular techniques are minimally invasive, safe, and effective. Knowledge of the characteristics and advantages/disadvantages of each agent helps in planning and appropriate selection of agents for the patient. We report successful embolization with improved clinical outcomes for the patient using precipitating hydrophobic injectable liquid (PHIL) embolic agent. The outcome and prognosis of SDAVF depend on the duration of symptoms, severity of neurological symptoms, and successful occlusion of the fistulous draining vein. Awareness of this rare condition amongst clinicians and radiologists, would enable an earlier diagnosis and avoid morbid outcomes of this treatable condition.

Microsurgical intraluminal obliteration of type IV perimedullary arteriovenous fistula with an in situ hemostatic agent: illustrative case

BACKGROUND

Spinal arteriovenous fistulas (SAVFs) are underdiagnosed entities that can lead to severe morbidity from spinal cord dysfunction or hemorrhage. Treatment options include endovascular embolization or direct surgical obliteration at the level of the arteriovenous shunt. The authors present a case of intraluminal microsurgical access for occlusion with a hemostatic agent of a type IV SAVF near the conus medullaris as an alternative to clip occlusion to avoid nerve root compromise.

OBSERVATIONS

Temporary microsurgical clipping of the SAVF led to nerve root compromise detected via intraoperative monitoring. Instead, the authors advanced elongated pieces of a hemostatic agent directly into the arterial lumen via arteriotomy to create direct obliteration of the fistula without intraoperative monitoring changes.

LESSONS

In patients unable to tolerate clipping of the SAVF because of nerve root involvement and neurophysiological signal decline, open access of the vessels and direct intraluminal obliteration using a hemostatic agent should be considered as an alternative method of fistula occlusion.

Vascular Myelopathies

There are many vascular disorders that can affect the spinal cord, and their prevalence and etiology are highly influenced by age, sex, and risk factors. This article reviews the embryology and anatomy of the spinal cord, as well as several vascular conditions, describing their clinical and imaging presentation, emphasizing the different imaging modalities' contributions to increasing specificity and better defining the most appropriate therapy strategy for improving the patient's prognosis.

Bilateral mirror image lumbar spinal dural arterial venous fistula: a rare case and systematic review of the literature

BACKGROUND

Spinal dural arteriovenous fistulas (SDAVF) are rare with an incidence of 5-10/million annually. They can be difficult to diagnose causing a delay in treatment with significant morbidity. We describe the first case in the literature of a symptomatic mirror lumbar SDAVF which may go unnoticed due to its unique vascular anatomy.

CASE DESCRIPTION

A 78-year-old gentleman presented with a progressive deterioration in his walking distance and urinary retention. An initial MRI scan of the whole spine did not show features suggestive of an underlying vascular malformation. During further investigations of neurological causes, the patient continued to have progressive symptoms over a 10-month period resulting in a repeat MRI scan. This showed a new finding of cord oedema without abnormal flow voids. He went on to have vascular imaging which demonstrated a mirror L3 SDAVF and underwent subsequent surgical management. At follow up there was a significant improvement in symptoms.

CONCLUSIONS

Completing a systematic review of the literature we find that the mirror lumbar SDAVF in our patient presented in a more aggressive manner with symptoms progressing faster than in single or multi-level SDAVF. Our case demonstrates how this unique vascular anatomy may result in a diagnostic challenge, behaving in an occult way where typical findings are not seen on initial MRI scanning. We provide an argument for early vascular imaging which can result in the treatment of these lesions in a timely manner.

Surgical evolution in spinal dural arteriovenous fistula treatment-a 7 years monocentric experience

Accounting for 70% of all spinal vascular malformations, spinal dural arteriovenous fistulas (SDAVF) are the most common type of malformation. Interruption of the fistulous arterialized vein point is the goal of surgical treatment. The aim of the study was to compare open surgery (laminectomy) versus minimal invasive surgery (MIS) in SDAVF treatment. Between March 2013 and March 2020, we retrospectively collected 21 consecutive adult patients with SDAVF. Since March 2017, MIS has been routinely used for surgical treatment. Pre- and post-operative clinical evaluations used Aminoff-Logue score (ALS). Complication rate was noted. Post-operative occlusion of the malformation was confirmed by digital subtraction angiography (DSA) in all patients. MIS was compared to open surgery in terms of efficacy and complications with statistical evaluation. Standard laminectomy was performed in 12 patients and MIS technique in 9 patients. No difference was noted on pre-operative parameters. ALS and MRI signs of myelopathy were improved in all cases except for 1 patient in each group. All SDAVFs were excluded based on post-operative DSA. Significant differences were noted between the 2 groups in terms of perioperative blood loss (p<0.001), post-operative pain visual analog scale values (p<0.001), and first time out of bed (p<0.001). Wrong level surgery occurred in one patient in each group; patients were re-operated using the same technique. No infection or cerebrospinal fluid (CSF) leak was noted. In our experience, MIS is a safe alternative to open laminectomy for SDAVF treatment. MIS contributes to patient comfort and minimizes blood loss without increasing complication rate.

A rare case of sacral epidural arteriovenous fistula with concomitant occult multiple lumbar epidural arteriovenous fistulas

We describe a rare case of sacral epidural arteriovenous fistulas (edAVFs) with atypical clinical course of treatment. A 78-year-old man with a history of spinal surgery presented progressive gait disturbance and urinary incontinence. Spinal angiography demonstrated a sacral spinal AVF fed by bilateral lateral sacral arteries, draining to the venous pouch with subdural drainage. The first treatment by direct interruption of a subdural drainer was incompletely finished. Postoperative reassessment by 3D imaging analysis led to the diagnosis of sacral edAVF and 3D understanding of its angioarchitecture. The second treatment by transarterial embolization (TAE) resulted in complete occlusion of a sacral edAVF. However, spinal venous congestion didn't improve, because the recruitment of occult edAVFs at the multiple lumbar levels and complex-shaped sacral ventral epidural venous plexus (VEP) were involved in the remnant of prior subdural drainage. The third treatment was performed by TAE for three occult edAVFs and the VEP compartment connecting between a patent edAVF and subdural drainage, which resulted in complete disappearance of spinal cord edema. Endovascular embolization of VEP compartment connecting to subdural drainage in addition to fistulous occlusion may be one of the treatment options for several edAVFs at the multiple spinal levels.

Sacral arteriovenous fistula with lower thoracic cord edema without perimedullary vein enlargement

Background

Sacral dural arteriovenous fistulas (AVFs) are often undiagnosed at the initial presentation due to their rarity.

Case Description

For 1 year, a 71-year-old man developed progressive motor and sensory disturbances in both legs. Magnetic resonance imaging showed spinal cord edema with mild contrast enhancement at the T9-10 and T12 levels. Although mild venous dilatation was observed only at the cauda equina level, it was not initially recognized as abnormal. Blood and cerebrospinal fluid tests and spinal angiography of the lower thoracic to upper lumbar levels were nonspecific. The patient was unsuccessfully treated with three courses of high-dose intravenous methylprednisolone. Ultimately, following repeat spinal angiography (i.e., including the bilateral internal iliac arteries) that revealed a low-flow sacral dural AVF supplied by the right lateral sacral artery, the patient underwent successful surgical venous AVF occlusion/transection.

Conclusion

In cases of spinal cord edema without perimedullary abnormal flow voids, careful spinal angiography including the sacral spine is necessary even if only minimal venous dilation is initially observed at the cauda equina level.

Cost-Effectiveness of Forgoing Postoperative Catheter Angiography After Microsurgical Occlusion of Spinal Dorsal Intradural Arteriovenous Fistulas

OBJECTIVE

Spinal dorsal intradural arteriovenous fistulas (DI-AVFs) represent 70% of all spinal vascular lesions. Diagnostic tools include pre- and postoperative digital subtraction angiography (DSA) and intraoperative indocyanine green videoangiography (ICG-VA). ICG-VA has a high predictive value in DI-AVF occlusion, but postoperative DSA remains a core component of postoperative protocols. The aim of this study was to evaluate the potential cost reduction of forgoing postoperative DSA after microsurgical occlusion of DI-AVFs.

METHODS

Cohort-based cost effectiveness study of all DI-AVFs within a prospective, single-center cerebrovascular registry from January 1, 2017, to December 31, 2021.

RESULTS

Complete data including intraoperative ICG-VA and costs were available for 11 patients. Mean (SD) age was 61.5 (14.8) years. All DI-AVFs were treated with microsurgical clip ligation of the draining vein. ICG-VA showed complete obliteration in all patients. Postoperative DSA was performed for 6 patients and confirmed complete obliteration. Mean (SD) cost contributions for DSA and ICG-VA were $11,418 ($4,861) and $12 ($2), respectively. Mean (SD) total costs were $63,543 ($15,742) and $53,369 ($27,609) for patients who did and did not undergo postoperative DSA, respectively. Comorbidity status was identified as the main driver of total cost (P = 0.01 after adjusting for postoperative DSA status).

CONCLUSIONS

ICG-VA is a powerful diagnostic tool in demonstrating microsurgical cure of DI-AVFs, with a negative predictive value of 100%. Eliminating postoperative DSA in patients with confirmed DI-AVF obliteration on ICG-VA may yield substantial cost savings, in addition to sparing patients the risk and inconvenience of a potentially unnecessary invasive procedure.

Spinal Extramedullary Arteriovenous Fistulas: A 15-Year Endovascular Treatment Experience in a Tertiary Care Hospital in Thailand

BACKGROUND

Spinal arteriovenous shunts are rare diseases. Different classifications have been proposed, but the most widely used are those classified by locations. Different locations (i.e., intramedullary and extramedullary) have different treatment outcomes and different posttreatment angiographical results. Our study presents the 15-year endovascular treatment outcomes of patients who had spinal extramedullary arteriovenous fistulas (AVFs) at Ramathibodi Hospital, which is a tertiary care hospital in Thailand.

METHODS

A retrospective medical record and imaging review of all patients with spinal extramedullary AVFs, which were confirmed by a diagnostic spinal angiogram in our institute from January 2006 to December 2020, were performed. The angiographic complete obliteration rate in the first session of endovascular treatment, clinical outcomes of the patients, and complications of the procedures for all eligible patients were analyzed.

RESULTS

Sixty-eight eligible patients were included in the study. The most common diagnosis was spinal dural AVF (45.6%). The most common presenting symptoms were weakness, numbness, and bowel-bladder involvement (70.6%, 67.6%, and 57.4%, respectively). Ninety-four percent had spinal cord edema in preoperative magnetic resonance imaging. All patients had pial venous reflux. Sixty-four patients (94.1%) received endovascular treatment as the first option. The complete obliteration rate in the first session of endovascular treatment was 75% and was high in all subgroups except for the perimedullary AVF group. The overall intraoperative complication of endovascular treatment was 9.4%. Follow-up imaging showed no residual AVF in 50 patients (87.7%). Most of the patients (57.4%) had improvement of neurological functions at 3- to 6-month follow-up.

CONCLUSION

Treatment results of spinal extramedullary AVFs were good in terms of angiographic aspects and clinical outcomes. This may have resulted from the locations of the AVFs, which mostly did not involve the spinal cord arterial supply, with the exception of perimedullary AVFs. Although perimedullary AVF is difficult to treat, it can be cured by careful catherization and embolization.

Functional Vascular Anatomy and Arteriovenous Shunts of the Spine

The history of vascular anatomy of the spinal cord and spine began in the late 19th century. With recent advances in endovascular and surgical treatment of vascular lesions of the spinal cord, understanding the vascular anatomy of the spinal cord has become more important than ever. Catheter angiography is the gold standard for diagnosing vascular lesions of the spinal cord, and the vascular architecture of the spinal cord itself is relatively simple, a repetition of basic longitudinal and axial structures. This review discusses the vascular anatomy of the spine and spinal cord from the embryological point of view, as well as an overview of typical spinal arteriovenous shunt diseases mainly depending on their locations: paraspinal, epidural, dural, perimedullary, intramedullary, filum terminale/cauda equina, craniocervical junction, and related diseases.

Syringomyelia secondary to thoracic spinal dural arteriovenous fistula presenting as paraparesis

Spinal dural arteriovenous fistula (SDAVF) is also known as a type 1 spinal arteriovenous malformation, representing the most frequent vascular malformation of the spine. A high suspicion index is often required for the initial diagnosis of SDAVF because of subtle magnetic resonance imaging signs. We present the case of a patient with SDAVF associated with syringomyelia of the thoracic spinal cord and hypothesize that a fistula might induce intramedullary fluid accumulation due to venous hypertension, which leads to syrinx formation.

Spinal Dural Arteriovenous Fistula: Insights Into Operative Management

Spinal Dural Arteriovenous Fistula (SDAVF) is a rare and complex vascular condition with significant neurological consequences if left untreated. We present a case of SDAVF in a 46-year-old male who presented with progressive myelopathy. The patient presented with a three-month history of progressive lower extremity weakness, numbness, urinary retention, constipation, and gait disturbance. The spine's magnetic resonance imaging (MRI) showed diffuse T2 hyperintensity and contrast enhancement from T11 to L1, raising the suspicion of an intradural spinal cord lesion. Further evaluation with spinal angiography revealed an SDAVF at the level of T11-T12. The patient underwent surgical resection of the fistula, His lower extremity weakness and numbness improved significantly after surgery, and he was discharged with a plan for close follow-up. Early diagnosis and appropriate treatment prevent neurological deficits and improve patient outcomes. Surgical resection of the fistula can significantly improve neurological symptoms and should be considered a treatment option for SDAVF.

"Missing-piece" sign with dural arteriovenous fistula at craniocervical junction: A case report

OBJECTIVES

Spinal dural arteriovenous fistula (sDAVF) is a rare and often underdiagnosed spinal disease. Early diagnosis is required because the deficits are reversible and delays in treatment cause permanent morbidity. Although the abnormal vascular flow void is a critical radiographic feature of sDAVF, they are not always present. A characteristic enhancement pattern of sDAVF has been recently reported as the "missing-piece" sign which can lead to the early and correct diagnosis.

METHODS

We presented imaging findings, treatment decisions, and the outcome of a rare case of sDAVF, in which the "missing-piece" sign appeared atypical.

RESULTS

A 60-year-old woman developed numbness and weakness in her extremities. Spinal MRI revealed longitudinal hyperintensity in the T2-weighted image, extending from the thoracic level to medulla oblongata. At first, myelopathy with inflammation or tumor was suspected because of the lack of flow voids and vascular abnormalities in CT-angiography and MR-DSA. However, we administered intravenous methylprednisolone and her symptom got worse with the appearance of the "missing-piece" sign. Then, we successfully diagnosed sDAVF by angiography. The "missing-piece" sign was considered to derive from inconsistency of the intrinsic venous system of spinal cord, with the abrupt segments without enhancement. The same etiology was considered in our case.

CONCLUSIONS

Detecting the "missing-piece" sign can lead to the correct diagnosis of sDAVF, even if the sign appeared atypical.

'Balloon pressure technique' for endovascular treatment of spinal cord arteriovenous fistulas: preliminary results in 10 cases

BACKGROUND

Spinal arteriovenous fistulas (SAVFs) are challenging lesions to treat by endovascular means. Our purpose was to report our early experience with dual lumen balloons (DLBs) for embolization of SAVFs using ethylene vinyl alcohol (EVOH) (the so-called 'balloon pressure technique' (BPT)).

MATERIALS AND METHODS

During the inclusion period, 10 consecutive patients (nine men, mean age 61.6 years) underwent endovascular treatment of a SAVF (seven dural SAVFs and three epidural SAVFs) at a single institution using the BPT. DLBs were used in all cases. In seven cases (70%), a regular DLB was used, while in three cases (30%), low profile DLBs were used. EVOH was used as the liquid embolic agent in all cases. Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated more than 3 months after the procedure.

RESULTS

Complete cure of the SAVF by endovascular means alone was obtained in 80% of cases (8/10). For the two patients with incomplete SAVF occlusion, surgery was successfully performed secondarily. No recurrence was found at the 3 month follow-up in the eight patients for whom complete occlusion was obtained at the end of the embolization procedure. No permanent clinical complication was recorded using the BPT. Clinical improvement was observed in 6/10 (60%) cases.

CONCLUSION

BPT was a feasible technique, with regular or low profile DLBs, for embolization of SAVFs. Our preliminary results suggest the safety and effectiveness of this technique.

Delayed Cerebral Ischemia after Embolization in Ruptured Spinal Arteriovenous Fistula with Subarachnoid Hemorrhage : A Case Report

Delayed cerebral ischemia (DCI) remains a devastating complication in subarachnoid hemorrhage (SAH), however, there were no present reports that is associated with a ruptured spinal arteriovenous fistula (sAVF). We would like to present a rare case of DCI following embolization of a ruptured perimedullary sAVF. Initially, the patient clinical symptoms mimic a SAH caused by a ruptured intracranial aneurysm. Further evaluation revealed that the SAH was caused by a ruptured perimedullary sAVF and the patient's condition improved following the embolization procedure. Three days later, the patient developed an acute left-sided facial and motor weakness, which persisted until the patient was discharged on the day-15 onset. A magnetic resonance imaging and angiography is performed 1.5 years after discharge and revealed no signs of cerebral infarction and hemorrhage. In this paper, we reported DCI after embolization in a ruptured sAVF with SAH, supported by evidence from the current literature. We would like to also stress the importance of complete spinal and cerebral vessel imaging to reveal the underlying abnormalities and determine the most appropriate intervention.

Anatomical study of the thoracolumbar radiculomedullary arteries, including the Adamkiewicz artery and supporting radiculomedullary arteries

OBJECTIVE

The aim of this paper was to identify and characterize all the segmental radiculomedullary arteries (RMAs) that supply the thoracic and lumbar spinal cord.

METHODS

All RMAs from T4 to L5 were studied systematically in 25 cadaveric specimens. The RMA with the greatest diameter in each specimen was termed the artery of Adamkiewicz (AKA). Other supporting RMAs were also identified and characterized.

RESULTS

A total of 27 AKAs were found in 25 specimens. Twenty-two AKAs (81%) originated from a left thoracic or a left lumbar radicular branch, and 5 (19%) arose from the right. Two specimens (8%) had two AKAs each: one specimen with two AKAs on the left side and the other specimen with one AKA on each side. Eight cadaveric specimens (32%) had 10 additional RMAs; among those, a single additional RMA was found in 6 specimens (75%), and 2 additional RMAs were found in each of the remaining 2 specimens (25%). Of those specimens with a single additional RMA, the supporting RMA was ipsilateral to the AKA in 5 specimens (83%) and contralateral in only 1 specimen (17%). The specimens containing 2 additional RMAs were all (100%) ipsilateral to their respective AKAs.

CONCLUSIONS

The segmental RMAs supplying the thoracic and lumbar spinal cord can be unilateral, bilateral, or multiple. Multiple AKAs or additional RMAs supplying a single anterior spinal artery are common and should be considered when dealing with the spinal cord at the thoracolumbar level.

Spinal Cord Infarction With Prolonged Femoral Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVES

There have been sporadic reports of ischemic spinal cord injury (SCI) during venoarterial extracorporeal membrane oxygenation (VA-ECMO) support. The authors observed a troubling pattern of this catastrophic complication and evaluated the potential mechanisms of SCI related to ECMO.

DESIGN

This study was a case series.

SETTING

This study was performed at a single institution in a University setting.

PARTICIPANTS

Patients requiring prolonged VA-ECMO were included.

INTERVENTIONS

No interventions were done. This was an observational study.

MEASUREMENTS AND MAIN RESULTS

Four hypotheses of etiology were considered: (1) hypercoagulable state/thromboembolism, (2) regional hypoxia/hypocarbia, (3) hyperperfusion and spinal cord edema, and (4) mechanical coverage of spinal arteries. The SCI involved the lower thoracic (T7-T12 level) spinal cord to the cauda equina in all patients. Seven out of 132 (5.3%) patients with prolonged VA-ECMO support developed SCI. The median time from ECMO cannulation to SCI was 7 (range: 6-17) days.There was no evidence of embolic SCI or extended regional hypoxia or hypocarbia. A unilateral, internal iliac artery was covered by the arterial cannula in 6/7 86%) patients, but flow into the internal iliac was demonstrated on imaging in all available patients. The median total flow (ECMO + intrinsic cardiac output) was 8.5 L/min (LPM), and indexed flow was 4.1 LPM/m². The median central venous oxygen saturation was 88%, and intracranial pressure was measured at 30 mmHg in one patient, suggestive of hyperperfusion and spinal cord edema.

CONCLUSIONS

An SCI is a serious complication of extended peripheral VA-ECMO support. Its etiology remains uncertain, but the authors' preliminary data suggested that spinal cord edema from hyperperfusion or venous congestion could contribute.

Thoracolumbar spinal dural arteriovenous fistulae present with longer arteriovenous transit compared to cranial and cervical dural fistulae

BACKGROUND

Thoraco-lumbar spinal dural arteriovenous fistulae represent a rare subset of central nervous system vascular malformations. One of the unique features of spinal dural arteriovenous fistulae is their extremely low propensity to cause hemorrhage (either parenchymal or subarachnoid), with a distinct clinical presentation of myelopathy secondary to spinal venous congestion. The exact mechanism for this unique presentation is still unclear.

METHODS

Following institutional review board approval, we retrospectively analyzed our prospectively maintained database of spinal dural arteriovenous fistulae and cranial (cr) DAVF cases presenting between 2008 and 2021. For all cases, angiograms were reviewed and arteriovenous transit times were calculated. Patient demographics, angiographic features, and clinical and radiological outcomes were assessed.

RESULTS

In total, 66 patients presenting with confirmed thoracolumbar spinal dural arteriovenous fistulaes were identified and compared to patients presenting with cervical spinal dural arteriovenous fistulaes (n  =  10), ruptured crDAVFs (n  =  32) and unruptured crDAVFs (n  =  20). Mean age in the target group was 66  ±  13 versus 57-62 in the other groups, p < 0.05 on one-way analysis of variance; with 80% males versus 50%-65% in other groups. Mean arteriovenous transit time in the thoracolumbar group measured 1.98 s ± 0.96 versus 0.25-0.5 s range in other groups (p < 0.0001 on one-way analysis of variance).

CONCLUSION

Prolonged arteriovenous transit times may represent a distinct feature of thoracolumbar spinal dural arteriovenous fistulaes. This may, amongst other factors, play a role in the observed lesser likelihood of hemorrhagic complications compared to other dural arteriovenous shunts.

MRI characteristics of lumbosacral dural arteriovenous fistulas

Background and purpose

Spinal dural arteriovenous fistulas located in the lumbosacral region are rare and present with nonspecific clinical signs. The purpose of this study was to find out the specific radiologic features of these fistulas.

Methods

We retrospectively reviewed the clinical and radiological data of 38 patients diagnosed with lumbosacral spinal dural arteriovenous fistulas in our institution from September 2016 to September 2021. All patients underwent time-resolved contrast-enhanced three-dimensional MRA and DSA examinations, and were treated with either endovascular or neurosurgical strategies.

Results

Most of the patients (89.5%) had motor or sensory disorders in both lower limbs as the first symptoms. On MRA, the dilated filum terminale vein or radicular vein was seen in 23/30 (76.7%) patients with lumbar spinal dural arteriovenous fistulas and 8/8 (100%) patients with sacral spinal dural arteriovenous fistulas. T2W intramedullary abnormally high signal intensity areas were found in all lumbosacral spinal dural arteriovenous fistula patients, with involvement of the conus present in 35/38 (92.1%) patients. The "missing piece sign" in the intramedullary enhancement area was seen in 29/38 (76.3%) patients.

Conclusion

Dilatation of the filum terminale vein or radicular vein is powerful evidence for diagnosis of lumbosacral spinal dural arteriovenous fistulas, especially for sacral spinal dural arteriovenous fistulas. T2W intramedullary hyperintensity in the thoracic spinal cord and conus, and the missing-piece sign could be indicative of lumbosacral spinal dural arteriovenous fistula.

Challenging Myelopathy Cases

Misdiagnosis of myelopathies is common and can lead to irreversible disability when diagnosis- and disease-specific treatments are delayed. Therefore, quickly determining the etiology of myelopathy is crucial. Clinical evaluation and MRI spine are paramount in establishing the correct diagnosis and subsequently an appropriate treatment plan. Herein, we review an approach to myelopathy diagnosis focused on the time course of neurologic symptom progression and neuroimaging pearls, and apply them to a variety of inflammatory, structural, and vascular myelopathy cases.

Recognition of the variant type of spinal dural arteriovenous fistula: a rare but important consideration

OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) typically represent abnormal shunts between a radiculomeningeal artery and radicular vein, with the point of fistulization classically directly underneath the pedicle of the vertebral body, at the dural sleeve of the nerve root. However, SDAVFs can also develop in atypical locations or have more than one arterial feeder, which is a variant of SDAVF. The aim of this study was to describe the incidence and multidisciplinary treatment of variant SDAVFs in a single-center case series.

METHODS

Following institutional review board approval, the authors retrospectively analyzed their prospectively maintained database of patients with SDAVFs who presented between 2008 and 2020. For all patients, spinal digital subtraction angiograms were reviewed and variant SDAVFs were identified. Variant types of SDAVFs were defined as cases in which the fistulous point was not located underneath the pedicle. Patient demographics, angiographic features, clinical outcomes, and treatment modalities were assessed.

RESULTS

Of 59 patients with SDAVFs treated at the authors' institution, 4 patients (6.8%) were identified as having a variant location of the shunt zone, pinpointed on the dura mater at the intervertebral level, further posteriorly within the spinal canal. In 3 cases (75%), a so-called bimetameric arterial supply was demonstrated.

CONCLUSIONS

Recognition of the variant type of SDAVF is crucial for management, as correct localization of the fistulous point and bimetameric supply are critical for successful surgical disconnection, preventing delay in achieving definitive treatment.

A Case of a Thoracic Arteriovenous Fistula Between an Intercostal Artery and a Pulmonary Vein

Arteriovenous (AV) fistulas are irregular connections between arteries and veins, and thoracic AV fistulas are rarely identified in clinical practice. We report a case of a 56-year-old female with a history of esophageal adenocarcinoma treated with radiation and resection who presented to the hospital due to hemoptysis. She underwent bronchoscopy revealing a tracheobronchial fistula, and esophagogastroduodenoscopy revealing active arterial bleed. Subsequent angiography uncovered an AV fistula between her right T8 intercostal artery and pulmonary vein with a pseudoaneurysm. She underwent coiling of her T8 and T9 intercostal arteries with resolution of her symptoms.

Imaging characteristics, misdiagnosis and microsurgical outcomes of patients with spinal dural arteriovenous fistula: a retrospective study of 32 patients

Background

Spinal dural arteriovenous fistula (SDAVF) is an extremely rare spinal vascular malformation. As SDAVF exhibits no specific clinical manifestations nor diverse imaging results, it is easily misdiagnosed, resulting in delayed treatment and irreversible neurological damage. Most patients were initially misdiagnosed, but there were few reports on reducing misdiagnosis.

Methods

A total of 32 consecutive patients, who presented to our institution (Shanghai Deji Hospital) with SDAVF between June 2013 and January 2016 were retrospectively analyzed. Data were collected on demographics, clinical presentation, imaging findings, follow-up, and clinical outcomes. The Aminoff-Logue scale (ALS) was used to assess clinical outcomes.

Results

Of the 32 enrolled patients (3 females, mean age 59.1±3.8 years), 23 patients (71.9%) were misdiagnosed as acute myelitis (11 patients), intramedullary tumors (6 patients), lumbar disc herniation (4 patients), and other conditions (2 patients). All patients underwent surgical procedures under electrophysiological monitoring. Fistulas were found in all 32 patients and were successfully occluded. The mean follow-up period was 19.22±8.21 months (ranging from 2 weeks to 30 months). One year later, 20 patients underwent magnetic resonance imaging (MRI), and 14 showed no T2 edema, and the edema was relieved in 6 patients. A total of 10 patients underwent enhancement MRI and no enhancement signs were detected. Among the 27 patients with long-time follow-up, the fistula had no residual or recurrence, 21 patients showed decreased ALS scores (P<0.05). Six patients exhibited nonsignificant improvement. No aggravating patient was found. Prognosis differed significantly between patients with ALS <6 and those with ALS ≥6 (P<0.05).

Conclusions

Spinal angiography should be performed with full intubation, and microcatheter angiography can reduce misdiagnosis. SDAVF must be differentiated from acute myelitis, intramedullary tumor, and other spinal vascular malformations. Microsurgical treatment is effective with a low recurrence rate.

Imaging of Common Spinal Cord Diseases

Spinal cord evaluation is an integral part of spine assessment, and its reliable imaging work-up is mandatory because even localized lesions may produce serious effects with potentially irreversible sequelae. Spinal cord alterations are found both incidentally during spine evaluation in otherwise neurologically asymptomatic patients or during neurologic/neuroradiologic assessment in myelopathic patients. Myelopathy (an umbrella term for any neurologic deficit that refers to spinal cord impairment) can be caused by intrinsic lesions or extrinsic mechanical compression, and its etiology may be both traumatic and/or nontraumatic. The symptoms largely depend on the size/extension of lesions, ranging from incontinence to ataxia, from spasticity to hyperreflexia, from numbness to weakness. Magnetic resonance imaging is the reference imaging modality in spinal cord evaluation, ensuring the best signal and spatial resolution. We provide an overview of the most common spinal cord disorders encountered by radiologists and describe the technical measures that offer optimal spinal cord visualization.

Reversible Symptom Aggravation by Intake of Taurine-Rich Foods in Patients with Venous Congestive Myelopathy: Controlled Case Series Study

Purpose

Reversible aggravation of myelopathy symptoms was observed after the intake of taurine-rich foods in patients with venous congestive myelopathy (VCM) caused by a spinal arteriovenous shunt (SAVS), and the taurine-challenge test was applied to demonstrate an association between taurine and VCM.

Materials and Methods

The current study reviewed any aggravation history of myelopathy symptoms, including walking difficulty, after consuming taurine-rich foods among 133 consecutive patients with a SAVS from a prospective institutional database from June 2013 to February 2021. The type of taurine-rich foods, demographic data, arteriovenous shunt level, and follow-up periods were obtained. For the controlled taurine challenge test, Bacchus^® (Dong-A Pharmaceutical, Seoul, Korea), a taurine-rich drink, was given to patients who fulfilled test criteria of recovered VCM (pain-sensory-motor-sphincter scale ≥2, improvement of spinal cord signal intensity on magnetic resonance imaging, and follow-up >6 months after SAVS treatment) to confirm the disappearance of such aggravation.

Results

Ten patients had an aggravation history related to food. Webfoot octopus, small octopus, squid, crab, scallop, and taurine-rich energy drink (Bacchus^®) were related to such aggravation in patients with VCM. Aggravation appeared about 30 minutes after food intake followed by expressions such as ‘I could not walk and collapsed to the ground’ and usually lasted for about 3 hours, followed by a slow recovery after taking rest. Four patients who met the test criteria underwent the taurine challenge with Bacchus^® and revealed no further symptom aggravation, suggesting that taurine did not affect patients after recovery from VCM.

Conclusion

The association between taurine-rich food and reversible symptom aggravation can appear in patients with VCM and disappear after VCM treatment. Aggravation of venous hypertension in the spinal cord is suggested as a mechanism but further elucidation is needed.

Potential biomarkers of spinal dural arteriovenous fistula: C4BPA and C1QA

Background and purpose

A major challenge in spinal dural arteriovenous fistula (SDAVF) is timely diagnosis, but no specific predictive biomarkers are known.

Methods

In the discovery cohort (case, n = 8 vs. control, n = 8), we used cerebrospinal fluid (CSF) and paired plasma samples to identify differentially expressed proteins by label-free quantitative proteomics. Further bioinformatics enrichment analyses were performed to screen target proteins. Finally, it was validated by ELISA in two of the new cohorts (case, n = 17 vs. control, n = 9), and univariate analysis, simple linear regression, and receiver operator characteristic (ROC) curve analysis were performed to evaluate the diagnostic potential.

Results

In the discovery cohort, the most overexpressed proteins were APOB and C4BPA in CSF samples of patients. The GO/KEGG enrichment analysis indicated that the upregulated proteins were mainly involved in the acute inflammatory response and complement activation. Hub-gene analysis revealed that APP might be the key protein in the molecular interaction network. In the validation cohort, C4BPA and C1QA were significantly overexpressed in the CSF of patients, averaging 3046.9 ng/ml and 2167.2 ng/ml, respectively. Simple linear regression demonstrated that levels of C1QA and C4 were positively correlated with total protein in CSF (R² = 0.8021, p = 0.0005; R² = 0.7447, p = 0.0013). The areas under the ROC curves of C4BPA and C1QA were 0.86 and 1.00, respectively.

Conclusions

This study was the first to identify C4BPA and C1QA as potential biomarkers for the diagnosis of SDAVF and revealed that complement pathway activation might be one of the molecular mechanisms for venous hypertension myelopathy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02522-x.

UPDATE ON MANAGEMENT OF DURAL ARTERIOVENOUS FISTULAS

Dural Arteriovenous Fistulas (AVF) represent about 10% of all intracranial vascular lesions. Although they seem benign in nature, the presence of retrograde venous makes them aggressive, with a high risk of complications. Patients may be clinically asymptomatic or experience symptoms ranging from mild to severe hemorrhage, depending on their location. Different treatments are available, but recently, the development of catheter intervention allows most patients to be cured with transcatheter embolization. Stereotactic radiosurgery achieves excellent rates of obliteration for low-grade lesions. In this review, we try to highlight the recent advances in the management of dural AVF.

Acute Cauda Equina Syndrome Caused by Epidural Steroid Injection in the Setting of a Spinal Dural Arteriovenous Fistula

We present a case of acute cauda equina syndrome caused by an epidural steroid injection in the setting of a previously undiagnosed spinal dural arteriovenous fistula (SDAVF). Our patient was a 61-year-old man who presented to the emergency department with low back pain, inability to walk, paresthesias of his bilateral lower extremities, bowel and bladder incontinence, and saddle anesthesia. Physical examination revealed weakness and decreased sensation of the lower extremities as well as poor rectal tone and urinary retention. Magnetic resonance imaging (MRI) revealed evidence of spinal cord edema in the T9-10 region and a probable SDAVF with secondary distal thoracic cord ischemia. This case highlights the importance of prompt recognition of cauda equina syndrome in the emergency department, expedient imaging, and efficient transfers of care, which allowed this patient to quickly undergo necessary surgery that led to an almost complete recovery. It also highlights the importance of recognizing subtle changes on lumbar MRI.

Concomitant spinal dural arteriovenous fistula and nodular fasciitis in an adolescent: case report

Background

Spinal dural arteriovenous fistula (SDAVF) usually occurs during the 4^th to 6^th decades of life, and adolescent SDAVF is rarely reported. SDAVF arising around a tumor is also rare, and reported tumors are mostly schwannoma and lipoma.

Case presentation

We reported a 16-year-old male presented with progressive weakness and numbness of lower limbs for 3 months. A SDAVF was found, which was fed by right radicular arteries from segmental artery at L2 level and drained retrogradely into perimedullary veins. A concomitant spinal extradural nodular fasciitis at right L1/L2 intervertebral foramen was also noted. The SDAVF was completely obliterated by endovascular treatment and the tumor was debulked. The patient recovered well after the procedures.

Conclusions

Our case report suggests SDAVF can occur in adolescent. The concomitant presence with a nodular fasciitis indicates that although it usually arises in subcutaneous tissue but can rarely form on the dura of spine.

Radiation Dose and Fluoroscopy Time of Diagnostic Angiography in Patients with Spinal Dural Arteriovenous Fistula

PURPOSE

Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a spinal angiography. The diagnostic reference level (DRL) for this specific endovascular procedure is still to be determined. This single-center study provides detailed dosimetrics of diagnostic spinal angiography performed in patients with SDAVFs.

METHODS

Retrospective analysis of all diagnostic spinal angiographies between December 2011 and January 2021. Only patients with an SDAVF who had baseline magnetic resonance angiography (MRA), diagnostic digital subtraction angiography (DSA), treatment and follow-up at this institution were included. Dose area product (DAP, Gy cm²) and fluoroscopy time were compared between preoperative and postoperative angiographies, according to SDAVF locations (common versus uncommon), MRA results at baseline (positive versus negative) and DSA protocols (low-dose, mixed-dose, normal-dose). The 75th percentile of the DAP distribution was used to define the local DRL.

RESULTS

A total of 62 spinal angiographies were performed in 25 patients with SDAVF. Preoperative angiographies (30/62, 48%) yielded a significantly higher DAP and longer fluoroscopy time when compared to postoperative angiographies (32/62, 53%) (p < 0.01). The local DRL was 329.41 Gy cm² for a nonspecific (n = 62), 395.59 Gy cm² for a preoperative and 138.6 Gy cm² for a postoperative spinal angiography. Preoperative angiography of uncommonly located SDAVFs yielded a significantly longer fluoroscopy time (p = 0.02). The MRA-based fistula detection had no significant impact on dosimetrics (p > 0.05). A low-dose protocol yielded a 61% reduction of DAP.

CONCLUSION

The results of the present study suggest novel DRLs for spinal angiography in patients with SDAVF. Dedicated low-dose protocols enable radiation dose optimization in these procedures.

Long-term outcomes and prognostic factors in patients with treated spinal dural arteriovenous fistulas: a prospective cohort study

OBJECTIVE

To define the pattern of long-term clinical outcomes and prognostic factors in patients with spinal dural arteriovenous fistulas (SDAVFs).

DESGIN

Prospective cohort study based on constantly recruiting patients with SDAVFs in two medical centres in China.

SETTING

Patients with SDAVFs were recruited consecutively between March 2013 and December 2014 in two referral centres.

PARTICIPANTS

A prospective cohort of 94 patients with SDAVFs was included in this study, and 86 patients (mean age 53.0 years, 71 men) completed the study. Patients who had previously undergone endovascular or neurosurgical treatment or had neurological dysfunction caused by other diseases or refused treatment were excluded.

INTERVENTIONS

All patients underwent neurosurgery or endovascular embolisation. These patients were evaluated with the modified Aminoff and Logue's Scale (mALS) 1 day before and 3, 6, 12 and 72 months after treatments.

RESULTS

The duration of symptoms ranged from 0.5 to 66 months (average 12.8 months). The location of SDAVFs was as follows: 33.7% above T7, 50.0% between/include T7 and T12% and 16.3% below T12. 75 patients (87.2%) underwent neurosurgical treatment, and 9 patients (10.5%) underwent endovascular treatment. 58 patients (67.4%) exhibited an improvement in mALS of one point or greater at 72 months. Patients with less disability were more likely to improve at 72 months (p<0.05). 48 patients (55.8%) showed deterioration at 72 months compared with 12 months. 61% of the patients suffered numbness, and 22% had pain before treatment. However, 81% of patients had numbness, and 28% had pain after treatment. This deterioration was related to 1-year mALS and age.

CONCLUSION

Nearly two-thirds of the patients experienced clinical improvement at 72 months, and preoperative (1 day before treatment) mALS was the strongest predictor of clinical improvement. However, 55.8% of patients showed deterioration after temporary recovery. All patients with SDAVFs should accept treatment as soon as possible.