Spinal and Paraspinal Arteriovenous Lesions

Single hole, high-flow, spinal cord peri-medullary arteriovenous fistula (PMAVF) in a child, treated with transarterial embolization: A case report

Peri-medullary arteriovenous fistula (PMAVF) is a rare spinal vascular malformation that manifests as progressive neurologic deficits or hemorrhage in the spinal canal. We report a case of high-flow PMAVF in a child, with a single feeder artery and a large venous pouch, which was successfully treated with transarterial endovascular intervention. A 2-year-old boy was referred with a progressive 2-year history of myelopathy. The MRI revealed a large venous pouch at the midthoracic spinal cord with segmental surrounding edema. A spinal angiogram confirmed high-flow PMAVF with a single feeder artery from the anterior radiculomedullary artery, draining into the peri-medullary vein. The patient underwent transarterial embolization at the distal feeder artery, resulting in gradual motor strength improvement. PMAVF is classified as type IV spinal vascular malformation, usually presenting as a large, high-flow fistula with multiple feeders, although there was only one in this case. PMAVFs are intradural and may cause severe neurologic deficits due to mass effect, venous congestion, or hemorrhage, hence requiring prompt treatment. Treatment options for PMAVF include microsurgery, endovascular intervention, or a combination of the 2. Endovascular intervention with coil or liquid embolic material is considered first-line treatment for IVc PMAVF, and effective in type IVb with good clinical outcome. PMAVF is a rare spinal vascular malformation commonly manifesting as severe neurologic deficits but has the potential of favorable outcomes with endovascular therapy. This case demonstrates a unique angioarchitecture of high-flow PMAVF with a single feeder artery and large venous pouch, treated successfully with endovascular therapy.

Pediatric non-galenic pial arteriovenous fistula's characteristics and outcomes: a systematic review

INTRODUCTION

Pediatric non-galenic pial arteriovenous fistulas (pAVFs) are rare vascular malformations that are characterized by a pial arterial-venous connection without an intervening capillary bed. Outcomes and treatment strategies for pAVFs are highly individualized, owing to the rarity of the disease and lack of large-scale data guiding optimal treatment approaches.

METHODS

We performed a systematic review of pediatric patients (< 18 years at diagnosis) diagnosed with a pAVF by digital subtraction angiogram (DSA). The demographics, treatment modalities, and outcomes were documented for each patient and clinical outcome data was collected. Descriptive information stratified by outcome scores were classified as follows: 1 = excellent (no deficit and full premorbid activity), 2 = good (mild deficit and full premorbid activity), 3 = fair (moderate deficit and impaired activity), 4 = poor (severe deficit and dependent on others), 5 = death.

RESULTS

A total of 87 studies involving 231 patients were identified. Median age at diagnosis was 3 years (neonates to 18 years). There was slight male preponderance (55.4%), and 150 subjects (81.1%*) experienced excellent outcomes after treatment. Of the 189 patients treated using endovascular approaches, 80.3% experienced excellent outcomes and of the 15 patients surgically treated subjects 75% had an excellent outcome. The highest rate of excellent outcomes was achieved in patients treated with Onyx (95.2%) and other forms of EvOH (100%). High output heart failure and comorbid vascular lesions tended to result in worse outcomes, with only 54.2% and 68% of subjects experiencing an excellent outcome, respectively. *Outcomes were reported in only 185 patients.

CONCLUSION

pAVFs are rare lesions, necessitating aggregation of patient data to inform natural history and optimal treatment strategies. This review summarizes the current literature on pAVF in children, where children presenting with heart failure as a result of high flow through the lesion were less likely to experience an excellent outcome. Prospective, large-scale studies would further characterize pediatric pAVFs and enable quantitative analysis of outcomes to inform best treatment practices.

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.

Arteriovenous shunts of the cervical spine: patient demographics, presentation, patterns of high-risk venous drainage, and updated classification

BACKGROUND

Intracranial dural arteriovenous (AV) fistula classifications focus on presence/absence of retrograde flow in the cortical veins of the brain as this angiographic finding portends a worse prognosis. However, prior categorization systems of AV shunts in the spine do not incorporate these features. We propose an updated classification for spinal shunting lesions that terms any shunting lesion with retrograde flow in any cortical vein of the brain or spinal cord medullary vein as "high risk". To present this classification, we analyzed our center's most recent experience with cervical spine shunting lesions.

METHODS

The electronic medical record at our institution was reviewed to identify shunting lesions of the cervical spine and patient demographics/presentation. Comprehensive craniospinal digital subtraction angiograms were evaluated to classify shunt location, type (arteriovenous malformation (AVM) vs arteriovenous fistula (AVF)), and presence of high-risk venous drainage.

RESULTS

Some 52 lesions were identified and categorized as pial/dural/epidural/paravertebral AVFs and intramedullary/extraspinal AVMs. Lesions were classified as high risk or not depending on the presence of retrograde flow into at least one vein that directly drains the spinal cord or brain. All patients who presented with either hemorrhage or infarct had underlying high-risk lesions. Additionally, 50% (17/34) of symptomatic patients with high-risk lesions presented with neurological extremity symptoms (OR=10.0, p=0.037) most of which fit a myelopathic pattern.

CONCLUSION

We present an updated classification system for shunting lesions of the spine that focuses on high-risk retrograde flow to the brain or spine in addition to anatomical location in order to better inform patient management.

Craniocervical dural arteriovenous fistula: Microsurgical clipping and technical nuances with ICG

A 48-year-old male with progressive congestive myelopathy had a craniocvervical DAVF treated with surgical clipping using ICG to confirm solitary inflow.

Clarifying the clinical landscape of pediatric spinal arteriovenous shunts: an institutional experience and individual patient-data meta-analysis

BACKGROUND

Pediatric spinal arteriovenous shunts (SAVS) are rare lesions with heterogeneous pathogenesis and clinical manifestations.

OBJECTIVE

To evaluate the clinical characteristics, angioarchitecture, and technical/clinical outcomes in SAVS through a large single-center cohort analysis and meta-analysis of individual patient data.

METHODS

A retrospective institutional database identified children (aged 0-21 years) who underwent digital subtraction spinal angiography (DSA) for SAVS between January 1996 and July 2021. Clinical data were recorded to evaluate angioarchitecture, generate modified Aminoff-Logue gait disturbance scores (AL) and McCormick grades (MC), and assess outcomes. We then performed a systematic literature review following PRISMA-IPD (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for individual patient data) guidelines, extracting similar data on individual patients for meta-analysis.

RESULTS

The cohort consisted of 28 children (M:F=11:17) with 32 SAVS lesions, with a mean age of 12.8±1.1 years at diagnosis. At presentation, SAVS were most highly concentrated in the cervical region (40.6%). Children had a median AL=2 and MC=2, with thoracolumbar AVS carrying the greatest disability. Among treated cases, complete obliteration was achieved in 48% of cases and median AL scores and MC grades both improved by one point. Systematic literature review identified 161 children (M:F=96:65) with 166 SAVS lesions with a mean age of 8.7±0.4 years. Among studies describing symptom chronicity, 37/51 (72.5%) of children presented acutely. At presentation, children had a median AL=4 and MC=3, with thoracolumbar AVS carrying the highest MC grades. After intervention, median AL and MC both improved by one point.

CONCLUSIONS

This study provides epidemiologic information on the location, onset, and presentation of the full spectrum of pediatric SAVS, highlighting the role of targeted treatment of high-risk features.

Diagnosis of spinal dural arteriovenous fistula: a multimodal MRI assessment strategy

AIM

To identify more specific screening indicators at magnetic resonance imaging (MRI) for the diagnosis of spinal dural arteriovenous fistulas (SDAVFs) and to determine an efficient diagnostic strategy.

MATERIALS AND METHODS

This retrospective study analysed clinical and imaging data of patients diagnosed with SDAVF and alternative myelopathy who underwent conventional MRI examinations. Additionally, three-dimensional (3D) T2-weighted sampling perfection with application-optimised contrasts using different flip-angle evolutions (3D-T2-SPACE) and contrast-enhanced magnetic resonance angiography (CE-MRA) data from patients with SDAVF were compared with digital subtraction angiography (DSA) data.

RESULTS

The age of onset, perimedullary flow voids (PFV), distribution of lesions, syringomyelia, degree of spinal oedema, and cauda equina disorder (CED) were factors that showed statistically significance in the identification of SDAVF with alternative myelopathy. After controlling for age, gender, PFV, degree of spinal cord swelling, and syringomyelia, the multivariable ordinal logistic regression model showed that the CED sign (OR = 32.46; 95% confidence interval [CI]: 2.47-427.15; p=0.008) was an independent predictor for SDAVF. The diagnostic model constructed using the PFV and CED signs had better diagnostic performance, with an area under the curve of 0.957 (p<0.001), maximum Youden index of 0.844, sensitivity of 92.9%, and specificity of 91.5%. Both 3D-T2-SPACE (77.8%) and CE-MRA (83.3%) sequences had good localisation values for SDAVF. Combining the two imaging examinations had better diagnostic accuracy than that of DSA.

CONCLUSION

CED and PFV on conventional MRI were specific indicators for the diagnosis of SDAVF. To compensate for the lack of fistula localisation on conventional MRI, 3D-T2-SPACE and CE-MRA can be used. Together they complement each other and have good diagnostic potential.

Intraspinal canal platform system for coil embolization of anterior spinal artery aneurysm associated with spinal cord arteriovenous malformation: a case report and literature review

BACKGROUND

The prognosis for spinal artery aneurysms associated with spinal cord arteriovenous malformations (AVMs) is poor because of the high rupture rate of aneurysms. However, endovascular treatment remains technically difficult because the catheter system must be constructed via the small-caliber anterior spinal artery (ASA) or posterior spinal artery (PSA), which feeds functionally eloquent spinal cord. A 2.6F Carnelian HF-S microcatheter (Tokai Medical Products, Aichi, Japan) has been specifically designed to assist a 1.6F Carnelian MARVEL S microcatheter (Tokai Medical Products) as a small-profile 'platform catheter' close to the target lesion. Here we present a prenidal ASA aneurysm treated using a 2.6F Carnelian HF-S microcatheter as an intraspinal canal platform catheter and review related literature.

CASE PRESENTATION

A 50-year-old man presented with a subarachnoid haemorrhage due to cervical spinal cord AVM. Diagnostic vertebral angiography revealed the AVM supplied by the PSA originated from the right C2 segmental artery and ASA arising from the right V4 segment. Superselective angiography for each feeder was achieved through a 2.6F Carnelian HF-S microcatheter, and a prenidal ASA aneurysm was diagnosed, which was clinically consistent with haemorrhagic origin. A 1.6F Carnelian MARVEL S microcatheter was cannulated into the aneurysm through the 2.6F Carnelian HF-S microcatheter positioned at the ASA. The aneurysm coiling was successfully performed without system instability or periprocedural complications.

CONCLUSIONS

Only a few cases have described endovascular treatment for spinal artery aneurysms. To date, no reports have been published regarding the use of an intraspinal canal platform catheter to treat spinal artery aneurysms. A 2.6F Carnelian HF-S microcatheter served as a useful intraspinal canal platform catheter for coil embolization of the ASA aneurysm. This system can provide excellent accessibility and controllability for endovascular treatment of spinal artery lesions.

Targeted embolisation for coexisting conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas with a varix on a shared drainer†

BACKGROUND

The coexistence of vascular malformations in the conus medullaris and cauda equina has been rarely reported, and the complex angioarchitecture in multiple arteriovenous lesions remains poorly understood.

CASE DESCRIPTION

A 17-year-old woman presented with a sudden-onset, stepwise worsening of weakness and pain in the bilateral legs. Angiography revealed conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas. One of the drainers was shared between the coexisting lesions and harboured a varix. Targeted embolisation of a fistulous point in the conus lesion was performed with precaution to prevent occluding the common drainage route, which led to symptom improvement with angiographical diminishment of the varix.

CONCLUSIONS

Recognising that communications between drainers can be observed in multiple spinal arteriovenous lesions is important in facilitating a safe embolisation. Cautious assessment of angiogram with fusion images of cone-beam computed tomography and volumetric T2 magnetic resonance imaging can help in establishing the diagnosis and treatment strategy.

Angiographic Index for the Treatment Efficacy and Functional Outcomes of Spinal Cord Arteriovenous Shunts: the Vertebral Blush Sign

BACKGROUND

The functional outcomes in spinal cord arteriovenous shunts (SCAVSs) are usually unpredictable from current assessments of treatment results. We aimed to investigate and propose a new index marker, the vertebral blush (VB) sign, for assessing the treatment efficacy of SCAVSs.

METHODS

This retrospective cohort study enrolled patients diagnosed with SCAVSs between June 2012 and May 2021. The VB sign was defined as the angiographic finding of reappearance or enhanced contrast staining of the vertebral bodies fed by shunt-related arteries observed after shunt occlusion. The primary outcome was the improvement in motor/sensory disturbances or sphincter impairments within 1 year after treatment. The secondary outcome was shunt recanalization. VB sign characteristics and associations with outcomes were analyzed.

RESULTS

Of 65 patients with SCAVSs, 57 were eligible for VB sign assessment; among these, there were 26 with the VB sign and 31 without the VB sign. Among vascular shunts perimedullary arteriovenous fistula showed the greatest difference in prevalence rate between those with and without the VB sign (33.3%, n = 9/27 versus 10.0%, n = 3/30; P = 0.031). On multivariable logistic regression analysis, SCAVSs with the VB sign had significantly more favorable outcomes than those without the VB sign (adjusted odds ratio, 5.61; 95% confidence interval, 1.48-21.23; P = 0.01). There was no relationship between the VB sign and secondary outcomes (P = 0.35).

CONCLUSION

The VB sign is independently associated with functional recovery after shunt occlusion and could be an assessment tool for the treatment efficacy of SCAVSs.

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.

Anatomical considerations regarding a high-flow arteriovenous fistula below the conus medullaris in a patient with hereditary hemorrhagic telangiectasia: Case report

BACKGROUND AND IMPORTANCE

Cauda equina radicular arteriovenous fistulas are rare "low flow" shunting lesions characterized by direct communication between the radicular artery and vein of a cauda equina nerve root. None have been associated with hereditary hemorrhagic telangiectasia and a high-flow cauda equina radicular arteriovenous fistula has never been reported. We present a unique case of a high-flow cauda equina radicular arteriovenous fistula in a patient with hereditary hemorrhagic telangiectasia. Marked flow-induced vascular remodeling posed significant diagnostic and therapeutic challenges which will be highlighted in this report.

CLINICAL PRESENTATION

A 39-year-old female with genetically confirmed hereditary hemorrhagic telangiectasia presented with progressive thoracic myelopathy secondary to a high-flow single-hole arteriovenous fistula below the conus. The feeding artery, arising from the anterior spinal artery, and draining vein had a paramedian course, favoring the diagnosis of a cauda equina radicular arteriovenous fistula (supplied by a proximal radicular artery) over a filum terminale arteriovenous fistula. Transarterial embolization was attempted but significant elongation and tortuosity of the anterior spinal artery precluded microcatheter access to the fistulous point. Surgical disconnection was successfully performed. The intraoperative findings supported the diagnosis of cauda equina radicular arteriovenous fistula. Delayed neurologic deterioration secondary to overshooting venous thrombosis was observed. She recovered after the initiation of therapeutic anticoagulation.

CONCLUSION

To the best of our knowledge, we hereby report the first high-flow cauda equina radicular arteriovenous fistula. The accurate differentiation of cauda equina radicular arteriovenous fistula from filum terminale arteriovenous fistulas, while challenging, is important to avoid treatment-related complications. Careful preoperative planning, the use of specialized endovascular and surgical techniques, and meticulous postoperative care can ensure the safe and complete disconnection of high-flow cauda equina radicular arteriovenous fistulas.

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.

Spontaneous obliteration of a spinal perimedullary fistula

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

Spontaneous regression of extradural high-flow vascular malformation in spinal arteriovenous metameric syndrome (SAMS): A unique case report

Background

Spinal arteriovenous metameric syndrome (SAMS) is a rare nonhereditary genetic vascular disorder, involving multiple layers of tissues in the same metameric level. Spontaneous regression of SAMS has never been reported in the medical literature.

Case Description

A 42-year-old woman presented with intermittent low back pain for 6 months. Magnetic resonance imaging of the thoracolumbar spine incidentally found clusters of spinal vascular malformations involving spinal cord, vertebral bodies, epidural space, and paraspinal muscles. There was no sign of venous congestion. Magnetic resonance angiography and spinal angiography revealed intradural spinal cord arteriovenous malformation (SCAVM) at the level of T10-11 and extradural high-flow osseous arteriovenous fistula. Due to asymptomatic SAMS and a high risk of anterior spinal arterial compromise during treatment, conservative treatment was considered in our patient. Spinal angiography obtained 8 years after initial angiography demonstrated significant regression of extradural component of SAMS and stable intradural SCAVM.

Conclusion

We describe a unique case of SAMS with spontaneous regression of extradural component during a long-term observation period.

Dorsal intradural spinal arteriovenous fistula associated with giant intradural spinal aneurysm, a case report

Arteriovenous fistula and spinal aneurysms like other vascular malformations can mimic radiculopathy and low back pain. Precise imaging work combined with a hybrid endovascular-microsurgical approach is the key element for the best clinical outcome.

'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.

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

BACKGROUND

 In the literature, filum terminale arteriovenous shunts (FTAVSs) always feature a single shunt point. Nidus-type FTAVSs have rarely been reported, and the best treatment strategy is unclear. This is a report of one exceptional case of a nidus-type FTAVS and surgical treatment of the lesion.

CASE DESCRIPTION

The patient suffered from cauda equina syndrome for 9 months. Magnetic resonance imaging and spinal angiography revealed a nidus-type FTAVF at the L2 level. Surgical resection was performed in the hybrid operating room, and the nidus was completely resected with the assistance of intraoperative methylene blue angiography and neurophysiological monitoring. The postoperative neurological function was stable.

CONCLUSIONS

A nidus-type arteriovenous shunt could originate from the FT, and in such cases, complete surgical resection with intraoperative neurophysiological monitoring in a hybrid operating room should be suggested.

Transvenous embolization of conus spinal arteriovenous malformation: illustrative case

BACKGROUND

Spinal arteriovenous malformations (AVMs) are the most challenging spinal vascular malformations. Endovascular transarterial embolization of spinal AVM has been well described. However, transvenous embolization has not been previously reported. In this case report, the authors describe transvenous embolization of a recurrent intramedullary/conus spinal AVM that was previously deemed unamenable to endovascular therapy.

OBSERVATIONS

A 30-year-old female presented with debilitating lumbar back pain and was found to have an intramedullary spinal AVM at the level of the conus medullaris. Initially, the AVM was treated with endovascular arterial embolization and subsequently with microsurgical resection. However, on follow-up angiography, the AVM had recurred. Further arterial embolization was deemed not possible because of anatomical challenges. After careful consideration, endovascular transvenous embolization was performed with successful occlusion of the AVM nidus.

LESSONS

Transvenous embolization is an alternative route for endovascular treatment of spinal AVMs that have an accessible single draining vein.

Spinal Vascular Shunts: Single-Center Series and Review of the Literature of Their Classification

Spinal arteriovenous shunts (sAVSs) are an uncommon disease, constituting 3 to 4% of intradural lesions; 70% of these lesions are spinal arteriovenous fistulas (sAVFs), whereas spinal arteriovenous malformations (sAVMs) are rarer. Both share the problem of their classification due to the heterogeneity of their angioarchitecture. The aim of this study is to report a series of sAVSs treated in the neurosurgery department of the Hospital Nacional Guillermo Almenara during the 2018–2020 period and to present an overview of the current literature on sAVS classification. We reviewed all medical records of patients diagnosed with sAVFs and sAVMs during the 2018–2020 period, and then we analyzed images with Horos v4.0.0, illustrated some cases with Clip Studio Paint v1.10.5, and performed a descriptive statistical analysis with SPSS v25. Twelve patients were included in this study, eight of which were women (67%) and four of which were men (33%); the age range was from 3 to 74 years. Eight sAVSs were sAVFs, whereas four were sAVMs. The most frequent clinical manifestation was chronic myelopathy in seven patients (58%). Of those treated only by embolization, seven (70%) resulted in complete occlusion (five sAVFs and two sAVMs), while three (30%) remained with a residual lesion. At last follow-up, five patients (42%) improved clinically, and the seven remaining (58%) maintained the same neurological state. sAVSs require a detailed study of their angioarchitecture for proper management. The endovascular treatment is safe with acceptable cure rates. The surgical option should not be set aside.

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

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

Spinal Osseous Epidural Arteriovenous Fistula with Intradural Reflux: A Case Report

The authors report a rare case of spinal osseous epidural arteriovenous fistula (AVF) with intradural reflux. A 71-year-old lady with a past history of a T12 compression fracture and neurofibromatosis type 1 presented with progressive paraparesis. Magnetic resonance (MR) images of the thoracolumbar spine showed edema of the spinal cord and flow voids. Catheter angiography revealed segmental arteries from T11 to L1 feeding an AVF in the epidural space. The AVF drained not only into the epidural venous plexus but also into the perimedullary veins. Of note, there was an intraosseous drainage route that involved the basivertebral vein of T12. Under the diagnosis of spinal osseous epidural AVF with intradural reflux, surgical interruption of the intradural arterialized draining vein was performed. Spinal osseous epidural AVF with intradural reflux is rare with only four cases reported in the past. We believe that spinal osseous epidural AVF should be recognized as a variant of spinal epidural AVF.

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.

Intracranial Subarachnoid Haemorrhage Caused by Cervical Spinal Dural Arteriovenous Fistulas: Case Report

Cervical spinal vascular abnormalities commonly present with progressive myelopathy as a result of venous congestion. They are not very prone to bleed and tend to be underdiagnosed due to their subtle clinical presentation. We came across a rare case of intracranial subarachnoid haemorrhage caused by cervical spinal dural fistula in the Imperial College Healthcare NHS Trust Hospitals/UK in June 2020. We diagnosed the patient under strict evidence base medicine guidance, which otherwise would have been missed. We discussed the case in several multidisciplinary team (MDT) meetings, and patient was treated under the joint care of the neurology and neurosurgical teams. Patient made a full recovery and discharged home with no neurological defects or complications. Here, we reported this case with all the evidence we gathered from our MDT discussion. We hope our experience would help improve the diagnosis and management protocol for future patients with a similar condition.

Embolization Tactics of Spinal Epidural Arteriovenous Fistulas

Purpose

Spinal epidural arteriovenous fistulas (SEDAVFs) show an epidural venous sac often with venous congestive myelopathy (VCM) due to intradural reflux at a remote level to which a transarterial approach would be difficult. We present 12 cases of SEDAVF with VCM and describe 3 main tactics for effective transarterial embolization.

Materials and Methods

Among 152 patients with spinal vascular malformations diagnosed in our tertiary hospital between 1993 and 2019, 12 SEDAVF patients with VCM were included. Three different transarterial embolization tactics were applied according to the vascular configuration and microcatheter accessibility. We evaluated treatment results and clinical outcomes before and after treatment.

Results

Transarterial embolization with glue (20–30%) was performed in all patients. The embolization tactics applied in 12 patients were preferential flow (n=2), plug-and-push (n=6), and filling of the venous sac (n=4). Total occlusion of the SEDAVF, including intradural reflux, was achieved in 11 (91.7%) of 12 patients, and partial occlusion was achieved in 1 patient. No periprocedural complications were reported. Spinal cord edema was improved in all patients for an average of 18 months after treatment. Clinical functional outcome in terms of the pain, sensory, motor, and sphincter scale and modified Rankin scores improved during a mean 25-month follow-up (6.3 vs. 3.3, P=0.002; 3.6 vs. 2.3, P=0.002, respectively).

Conclusion

Endovascular treatment for 12 SEDAVF patients with VCM achieved a total occlusion rate of 91.7% without any periprocedural complication. The combined embolization tactics can block intradural reflux causing VCM, resulting in overall good clinical outcomes.

Natural History and Clinical Outcomes of Paravertebral Arteriovenous Shunts

BACKGROUND AND PURPOSE

Paravertebral arteriovenous shunts (PVAVSs) are rare. Whether the intradural venous system is involved in drainage may lead to differences in clinical characteristics through specific pathophysiological mechanisms. This study aims to comprehensively evaluate the natural history and clinical outcomes of PVAVSs with or without intradural drainage.

METHODS

Sixty-four consecutive patients with PVAVSs from 2 institutes were retrospectively reviewed. Lesions were classified as type A (n=28) if the intradural veins were involved in drainage; otherwise, they were classified as type B (n=36). The clinical course from initial presentation to the last follow-up was analyzed.

RESULTS

The patients with type A shunts were older at presentation (52.5 versus 35.5 years, P<0.0001) and more likely to have lower spinal segments affected than patients with type B PVAVSs (67.8% versus 13.9%, P=0.00006). After presentation, the deterioration rates related to gait and sphincter dysfunction were significantly higher in patients with type A than type B shunts (gait dysfunction: 71.8%/y versus 17.0%/y, P=0.0006; sphincter dysfunction: 63.7%/y versus 11.3%/y, P=0.0002). According to the angiogram at the end of the latest treatment, 79% of type A and 75% of type B PVAVSs were completely obliterated. If the lesions were partially obliterated, a significantly higher clinical deterioration rate was observed in patients with type A shunts than those with type B shunts (69.9%/y versus 3.2%/y, P=0.0253).

CONCLUSIONS

Type A PVAVSs feature rapid progressive neurological deficits; therefore, early clinical intervention is necessary. For complex lesions that cannot be completely obliterated, surgical disconnection of all refluxed radicular veins is suggested.

Pressure Cooker Technique for Endovascular Treatment of Spinal Arteriovenous Fistulas: Experience in 15 Cases

BACKGROUND AND PURPOSE

Spinal arteriovenous fistulas are challenging to cure by endovascular means, with a risk of incomplete occlusion or delayed recurrence. The authors report herein their preliminary experience using the pressure cooker technique for the embolization of spinal arteriovenous fistulas.

MATERIALS AND METHODS

Fifteen patients (8 men; mean age, 60.3 years) underwent an endovascular treatment of a spinal arteriovenous fistula (12 dural spinal arteriovenous fistulas and 3 epidural spinal arteriovenous fistulas) in 2 different institutions using the pressure cooker technique. Two microcatheters could be navigated in the segmental artery in all patients using 2 guiding catheters. A proximal plug was achieved with highly concentrated cyanoacrylate ± coils. The liquid embolic agent injected to cure the fistula was diluted cyanoacrylate (n = 11) or ethylene-vinyl alcohol (n = 4). Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated at follow-up.

RESULTS

One (6.7%) procedure-related complication was recorded, which consisted of a transient radicular deficit, related to nerve root ischemia. Clinical improvement was observed in 10/14 (71%) patients for whom clinical follow-up was available. Complete spinal arteriovenous fistula occlusion on a follow-up angiography was observed in 11/12 patients (91.7%) for whom angiographic follow-up was available. One patient (8.3%) presented with a delayed recurrence at 29 months.

CONCLUSIONS

The pressure cooker technique is feasible, with either glue or ethylene-vinyl alcohol, for the embolization of spinal arteriovenous fistulas. Our results suggest the safety and effectiveness of this technique.

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

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

Vascular Myelopathies

PURPOSE OF REVIEW

Neurologists should be able to identify clinical and neuroimaging features that distinguish vascular disorders from other causes of myelopathy.

RECENT FINDINGS

Although certain clinical features suggest a vascular etiology in acute and chronic myelopathy settings, accurate MRI interpretation within the clinical context is key. Recent studies have shown vascular myelopathies are frequently misdiagnosed as transverse myelitis, and recognition of this diagnostic pitfall is important. Many different vascular mechanisms can cause myelopathy; this article provides a comprehensive review that simplifies disease categories into arterial ischemia, venous congestion/ischemia, hematomyelia, and extraparenchymal hemorrhage.

SUMMARY

It is important to recognize and manage vascular disorders of the spinal cord as significant causes of acute, subacute, and progressive myelopathy.

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

BACKGROUND

The 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 the potential of four-dimensional DSA (4D-DSA) (Siemens Healthcare) in the exploration of SVMs.

METHODS

We retrospectively studied all patients who underwent spinal DSA, including 4D-DSA acquisition, from July 2018 to June 2019 at a single institution. All spinal DSA acquisitions were performed under general anesthesia. 4D-DSA acquisitions were acquired with the protocol '12 s DSA Dyna4D Neuro'. 12 mL of iodixanol 320 mg iodine/mL were injected via a 5 F catheter (1 mL/s during the 12 s 4D-DSA acquisition). Inter-rater (three independent reviewers) and intermodality agreements were assessed.

RESULTS

Nine consecutive patients (six men, three women, mean age 55.3±19.8 years) with 10 SVMs (spinal dural arteriovenous fistulas n=3, spinal epidural arteriovenous fistulas n=2, spinal pial arteriovenous fistulas n=2, and spinal arteriovenous malformations n=2; one patient had two synchronous pial fistulas) had spinal DSA, including 4D-DSA acquisition. Inter-rater agreement was good and moderate for the venous drainage pattern and the SVM subtype, respectively. In 9 of 10 cases, the quality of the acquisition was graded as good. Satisfactory concordance between 4D-DSA and the selective microcatheterization was observed in 90% of cases for the location of the shunt point.

CONCLUSION

4D-DSA acquisition may be helpful for a better understanding of the angioarchitecture of SVMs. Larger series are warranted to confirm these preliminary results.

Transvenous embolization for craniocervical junction epidural arteriovenous fistula with a pial feeder aneurysm

Arteriovenous fistulas at the craniocervical junction are rare vascular malformations with frequent hemorrhagic presentations, which may have a concurrent pial feeder aneurysm. A 65-year-old man presented with subarachnoid hemorrhage and angiography showed an epidural arteriovenous fistula at the C-2 level with an anterior spinal feeder aneurysm without perimedullary venous drainage. Transarterial coil embolization of the ruptured aneurysm and partial Onyx embolization of the shunt led to thrombosis of the aneurysm. However, three years later angiography showed an increased shunt flow and recurrence of the aneurysm. Transvenous embolization of the shunt using coils and Onyx yielded complete obliteration of the shunt, thus leading to occlusion of the aneurysm. This case demonstrates that partial transarterial embolization of arteriovenous fistula leaves a risk of rebleeding, whereas complete obliteration of the shunt with a transvenous approach can lead to disappearance of the flow-related aneurysm without embolization of the aneurysm itself.

Republished: Spinal arteriovenous malformation without endovascular arterial access: is a combined neurosurgical approach and direct venous puncture an option?

This case report describes a combined neurosurgical and endovascular approach for the treatment of a conus medullaris arteriovenous malformation resulting in considerable improvement in the patient's neurological condition (modified Rankin Scale score 2).

Spinal arteriovenous malformation without endovascular arterial access: is a combined neurosurgical approach and direct venous puncture an option?

This case report describes a combined neurosurgical and endovascular approach for the treatment of a conus medullaris arteriovenous malformation resulting in considerable improvement in the patient's neurological condition (modified Rankin Scale score 2).