Cervical anterior spinal artery infarction associated with anomalous vertebral artery: a case report.

We report a unique case of cervical anterior spinal artery (ASA) infarction in a 49-year-old male with hypercholesterolemia and sleep apnea. The patient experienced sudden cervical pain, quadriparesis, areflexia, and urinary incontinence after swallowing a large food bolus. Imaging revealed an infarction at the C3-C5 levels and an anomalous right vertebral artery (VA) originating from the thoracic aorta, tightly enclosed between the aorta and a vertebral column with an anterior osteophyte. This aberrant VA was the primary vascular supply to the ASA, with no contribution from the left VA or supreme intercostal arteries. We propose that transient injury to the right VA, induced by compression between the aortic arch, the food bolus, and the osteophyte, led to temporary hypoperfusion of the ASA, causing a watershed ischemic injury in the mid cervical cord's anterior gray matter. The article also provides an in-depth discussion of the developmental and clinical characteristics associated with this rare vascular anomaly.

Two pediatric observations of spinal extradural arteriovenous fistulas presenting with epidural hemorrhages and cord compression.

We report two cases of acute spinal cord compression in children with low-flow spinal epidural arteriovenous fistulas (SEAVFs) and discuss the clinical presentation and management of these vascular anomalies. While most low-flow SEAVFs without radiculomedullary drainage are benign lesions typically diagnosed incidentally, we suggest that asymptomatic lesions may warrant aggressive management in specific circumstances, including lesions diagnosed at an early age or in patients under anticoagulation therapy. Our observations also emphasize that patients with a "spontaneous" epidural hemorrhage should undergo dedicated preoperative or postoperative vascular imaging to identify a possible underlying vascular anomaly.

Bilateral Dilated Superior Ophthalmic Veins in a Patient With an Arteriovenous Dialysis Fistula.

A 64-year-old man presented with 4 months of diplopia. He had end-stage renal disease requiring a cephalic transposition brachiocephalic fistula that was no longer in use following successful renal transplantation. On presentation, he had bilateral proptosis, extraocular movement restriction, chemosis, tortuous episcleral vessels, and caruncular injection. Non-contrast CT of the orbits demonstrated dilation of both superior ophthalmic veins, and CT angiography showed asymmetric enlargement of both cavernous sinuses and superior ophthalmic veins. A carotid-cavernous fistula was suspected, but cerebral angiography revealed shunting from the old fistula with intracranial drainage and cerebral venous hypertension. Aberrant retrograde drainage resulted from anatomical compression of the left brachiocephalic vein. The fistula was ligated, and at 1-week follow-up, the patient had marked improvement in extraocular movements and orbital congestion with near complete resolution of diplopia. Postoperative CT angiography obtained 2 months later demonstrated decreased size of both superior ophthalmic veins, consistent with improvement of venous hypertension.

Tracheobronchial arterial variants of vertebral artery origin and bronchovertebral arterial anastomoses.

PURPOSE: This report describes a series of angiographic observations of tracheobronchial arterial variants and discusses their clinical implications. METHODS: The angiographic features of eleven aberrant tracheal or bronchial arteries are reported, including four variants originating from the vertebral artery and two cases of bronchovertebral anastomosis. An additional observation of thyrothymic artery illustrates the discussion of the mechanisms involved in the development of these variants. RESULTS: Tracheobronchial arterial variants are predominantly left-sided variants (9 out of 11). They are linked to dominant paratracheal arterial connections, particularly the lateral longitudinal anastomosis. Unusual bronchial arteries of vertebral origin show a strong association with aberrant left vertebral arteries of aortic or proximal subclavian origin. CONCLUSION: This report presents a spectrum of tracheo-broncho-vertebral variations and emphasizes the role of previously described paratracheal arterial anastomoses in their formation. These variants can play a critical role during hemoptysis embolotherapy, either as an occult source of hemorrhage or as a risk factor for devastating complications.

Spinal fistulas documented by contrast enhanced computed tomography during myelopathy workup: a lost opportunity.

PURPOSE: Low-flow spinal arteriovenous fistulas (SAVFs) with intradural venous drainage typically manifest with a progressive venous hypertensive myelopathy (VHM) in older patients. VHM is difficult to identify. MRI is often nonspecific, and many cases are initially misdiagnosed, most often as transverse myelitis. The workup of myelopathic patients frequently includes thoracic and/or abdominal contrast-enhanced CT (CECT) that are generally not reviewed by neuroradiologists. The purpose of this work was to investigate how often abnormal enhancing intracanalar structures corresponding to the draining veins of a low-flow SAVF were documented by CECT. MATERIALS AND METHODS: We evaluated 92 consecutive patients with low-flow SAVFs and VHM treated at our institution between 2009 and 2018. The study group included 22 of these patients with at least one thoracoabdominal CECT available for review. The control group consisted of 20 consecutive myelopathy patients with negative angiography and at least one thoracoabdominal CECT. Intracanalar enhancing structures were classified either as (i) conspicuous or (ii) equivocal or absent. RESULTS: One CECT in the study group was technically inadequate. Conspicuous intracanalar enhancing structures were observed in 20 of the remaining 21 patients with SAVFs (95.2%) and in 2 of 20 control patients (10%). None of the enhancing intracanalar structures was mentioned in official study reports. CONCLUSIONS: The presence of enhancing vascular structures within the spinal canal on thoracoabdominal CECT obtained during the workup of myelopathies appears to represent a powerful but currently underappreciated tool for the detection of low-flow SAVFs.

Mechanical Thrombectomy for Acute Ischemic Stroke: Considerations in Children.

The use of mechanical thrombectomy for the treatment of acute childhood arterial ischemic stroke with large vessel occlusion is increasing, with mounting evidence for its feasibility and safety. Despite this emerging evidence, clear guidelines for patient selection, thrombectomy technique, and postprocedure care do not exist for the pediatric population. Due to unique features of stroke in children, neurologists and interventionalists must consider differences in patient size, anatomy, collateral vessels, imaging parameters, and expected outcomes that may impact appropriate patient selection and timing criteria. In addition, different causes of stroke and comorbidities in children must be considered and may alter the safety and efficacy of thrombectomy. To optimize the success of endovascular intervention in children, a multidisciplinary team should take into account these nuanced considerations when determining patient eligibility, developing a procedural approach, and formulating a postprocedure neurological monitoring and therapeutic plan.

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

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

Unilateral segmental agenesis of the vertebral artery at the C2 level.

PURPOSE: To report a case of unilateral segmental agenesis of the vertebral artery (VA). METHODS: We describe the angiographic and MRI features of a segmental VA agenesis (C2 segment). RESULTS: VA agenesis is caused by the absence of the anastomotic connection normally linking two adjacent intersegmental arteries; in the reported observation, a paravertebral extraforaminal anastomosis replaced the C2 segment normally joining the 1st and 2nd cervical intersegmental arteries through the C2 transverse foramen. CONCLUSION: We present an observation of segmental VA agenesis. This variant is consistent with the developmental history of the VA. It appears exceptional but is more likely underappreciated.

Dural venous sinus stenting as a stand-alone treatment for spontaneous skull base CSF leak secondary to venous pseudotumor cerebri syndrome.

Most spontaneous CSF leaks (SCSFL) are associated with an underlying pseudotumor cerebri syndrome (PTCS). Treatment generally includes surgical leak repair and PTCS correction, as untreated PTCS carries a risk of recurrence. We describe a 72-year-old woman with rhinorrhea, aural fullness, and posterior nasal drip. CT and MRI showed signs of CSF hypovolemia and PTCS, as well as bilateral transverse sinus stenoses. CT and MRI cisternography documented CSF leaks through the right cribriform plate and the posterior aspect of the petrous bone. Opening CSF pressure was 6 cm H2O. Dural venous sinus stenting (DVSS) was performed after failed conservative treatment. Rhinorrhea resolved 3 days after stenting, aural fullness 1 month later. After 6 months, signs of CSF hypovolemia had disappeared on MRI and the stents were patent. After 9 months, the patient had a transient, spontaneously resolving episode of rhinorrhea. She has been symptom-free for the remaining 39 months of follow-up.

A case of right aortic arch with isolated left innominate artery and global cerebral white matter atrophy.

A right aortic arch with an isolated left innominate artery is a rare form of aortic arch anomaly. We present a case of neonatal diagnosis of this anomaly with concerning findings of global cerebral white matter atrophy at 13 months of age.

Susceptibility weighted imaging in infants with staged embolization of vein of Galen aneurysmal malformations.

BACKGROUND AND PURPOSE: The vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation with a higher morbidity and mortality, especially in neonates. Ultrasound, CT and MR are usually used in diagnosis and treatment monitoring of these disorders. In this current study, we aim to examine utility of SWI in evaluation of treatment response in infants with VGAM. MATERIALS AND METHODS: We performed a retrospective chart analysis of children with VGAM in our institution between January 2008 and December 2016. Inclusion criteria included; confirmed VGAM on DSA; available SWI sequence at baseline and at follow up after at least a single embolization session; age at initial MR of 18 years or younger. Signal intensity and Angioarchitecture of VGAM and cerebral veins on SWI, as well as hydrocephalus and clinical outcome were evaluated. RESULTS: Of 11 patients identified with VGAM in our institution, 5 children (3 males and 2 females) satisfied the inclusion criteria. The average age at initial MR was 29 days (range 1-120). Fourteen MRI were available for review. All children had VGAM of mural type. Intramedullary veins were dilated and SWI-hypointense in all children, while subependymal and sulcal veins were dilated and SWI-hypointense in 4 patients on initial MRI. On the first available follow up MRI, cerebral veins have mostly normalized in 4 children and remained mostly dilated and SWI-hypointense in 1 child; even after complete treatment of the VGAM. CONCLUSION: Our preliminary findings show that SWI seems to offer a beneficial non-invasive tool in evaluating passive venous congestion patterns in pediatric patients with VGAM. It remains to be determined in larger studies, the clinical significance of these SWI changes.

Vertebral artery triplication.

PURPOSE: To report an extremely rare vertebral artery (VA) origin configuration. METHODS: Angiographic and MRI features of a VA triplication in a child are presented. RESULTS: The VA trifurcation was the result of the simultaneous persistence of the 4th, 5th and 6th primitive cervical intersegmental arteries, respectively, reaching the transverse canal at C4, C5 and C6. A contralateral VA duplication was noted as well. CONCLUSION: A previously undocumented instance of VA triplication is presented. Knowledge of such variations is important for the planning of diagnostic and therapeutic cervicocranial angiography and the understanding of unusual images on noninvasive imaging studies. This type of anomaly also represents a risk factor for arterial dissection.

Spinal dural arteriovenous fistula (SDAVF) variant with dual perimedullary and epidural drainage.

PURPOSE: A spinal dural arteriovenous fistula (SDAVF) is an abnormal connection between a radiculomeningeal artery and a radiculomedullary vein (RMV) characteristically draining into the perimedullary venous system. We present an observation of SDAVF draining simultaneously into the perimedullary and epidural venous systems. METHODS: A 67-year-old man presented with lower extremity weakness and sphincter dysfunction. MRI documented a longitudinally extensive myelopathy with parenchymal enhancement and flow-voids on T2-weighted images. Spinal angiography revealed the presence of two SDAVFs, at left T9 and right L1. RESULTS: The right L1 SDAVF was treated endovascularly. Superselective angiography of the main feeder, a right T12 radiculomeningeal branch, documented an unusual drainage pattern, with contrast flowing both retrogradely towards the perimedullary venous system and antegradely into the epidural plexus. The meningeal branch was embolized using a liquid embolic agent with adequate penetration of the embolic material into the proximal segment of the draining vein. The left T9 SDAVF was surgically resected, as the radicular artery supplying the fistula also provided the artery of Adamkiewicz. CONCLUSIONS: Dual drainage of the right L1 SDAVF into the perimedullary and epidural venous systems allowed to locate the site of the arteriovenous shunt at the point of transdural passage of the RMV, a narrowed segment also known to represent an anti-reflux mechanism. The potential role played by the topographical relationship between the shunt and the anti-reflux mechanism of the RMV in the formation and clinical expression of SDAVFs is discussed.

Spontaneous resolution of low-flow spinal arteriovenous fistulas.

PURPOSE: Spinal vascular anomalies with arteriovenous blood shunting include spinal arteriovenous malformations (SAVMs) and spinal arteriovenous fistulas (SAVFs), which are distinguished by the presence or absence of an interposed nidus. SAVFs can be further characterized based on their location (perimedullary, dural, or extradural) and flow pattern (high-flow versus low-flow shunts). The spontaneous resolution of a spinal vascular malformation, i.e., the complete disappearance-in the absence of therapeutic measures-of a lesion previously identified by angiography, seems to represent an exceptional phenomenon. METHODS: This study retrospectively analyzed seven patients with spontaneously resolving spinal vascular malformations observed by the senior author between January 2008 and April 2017. RESULTS: A total of 143 spinal vascular malformations were angiographically evaluated during the considered time period, including nine spontaneously resolving SAVFs in six patients, seven spinal epidural fistulas, and two spinal dural arteriovenous fistula. CONCLUSION: The "spontaneous" resolution of spinal vascular malformations appears to selectively involve SAVFs. While vessel wall alterations previously documented on the venous side of SAVFs may play an important role in the regression of these lesions, angiography seems to represent a significant contributing factor, probably through the prothrombotic properties of nonionic contrast agents.

Anterior disco-osteo-arterial conflict as a cause of intersegmental arterial flow impairment and spinal cord ischemia.

INTRODUCTION: This article describes anterior disco-osteo-arterial conflict as an insofar unsuspected mechanism of arterial flow impairment potentially leading to spinal cord ischemia and infarction. METHODS: The anterior disco-osteo-arterial conflict described in this report is illustrated with angiographic observations of patients presenting with spinal cord ischemia documented by MRI, and radiculomedullary flow impairment diagnosed by spinal digital subtraction angiography and spinal CTA. RESULTS: Proximal intersegmental artery flow impairment was found in association with anterior disc bulging and anterior osteophytic formation, alone or in combination. Patients either presented with an initial acute medullary syndrome or with a long-standing history of spinal claudication with acute secondary pejoration. CONCLUSION: Spinal ischemia can be the result of intersegmental and radiculomedullary flow impairment caused by an anterior disco-osteo-arterial conflict.

Acute, subacute, and long-term evaluation of a novel endovascular occlusion system in a large animal model.

OBJECTIVES: Endovascular occlusion of blood vessels represents a key component of interventional therapy. While coils are most commonly used, vessel occlusion is generally not achieved immediately and may necessitate a large number of devices. It has been suggested that endovascular plugs may overcome these limitations; however, immediate and durable occlusion remains a challenge with plugs as well. This study evaluates a newly designed endovascular occlusion system (EOS) METHODS: The EOS combines a nitinol coil with an impermeable membranous cap made of expanded polytetrafluoroethylene. The coil offers sufficient radial force to expand the membrane and minimize post-deployment migration. Fifteen test devices were deployed in the iliac (external and internal) and femoral arteries of five miniature swine, while two commercially available devices (platinum coils and a vascular plug) were used as controls in one miniswine. Angiography was performed 1, 5, and 10 minutes after device implantation. Follow-up angiography was obtained either on day 29 or day 61, prior to devices harvesting for histological evaluation and biocompatibility assessment. RESULTS: No clinical complications were observed in the animals throughout the study course. All test devices were deployed as intended, and produced complete and immediate vessel-occlusion. No recanalization or acute migration was observed within 10 minutes of deployment, whereas five test devices had migrated between 5 and 15 mm at follow-up angiography. Complete and durable vessel-occlusion without any sign of recanalization was observed in all EOS devices during the follow-up period. CONCLUSION: The EOS is a safe and reliable device resulting in immediate and durable vessel occlusion in the peripheral arterial circulation. While no device migration was observed in the pelvic area, it was observed with five test and one control devices in the vicinity of highly mobile articulations, leading to the conclusion that occlusion devices should not be placed within hypermobile areas such as the hip joint.

A large display is a powerful tool to reduce radiation exposure during single-plane fluoroscopically guided procedures.

OBJECTIVE: Magnification is a well-known, but often overlooked, factor impacting radiation exposure. Modern angiography units are commonly offered with single large monitors that allow multiple configurations, including wide display setting in addition to standard display setting similar to a classic arrangement of multiple monitors. CONCLUSION: By reducing the need for magnification, the wide display mode of large angiography monitors is a simple but extremely efficient tool to decrease radiation exposure to patients and care providers during single-plane procedures.

Diploic arteriovenous fistulas--classification and endovascular management.

BACKGROUND: The authors report on two cases of diploic arteriovenous fistulas (AVFs) in the left parieto-occipital region of a 20-year-old female and the right parietal region of a 68-year-old male. The clinical presentation, angiographic appearance, and endovascular management of these rare lesions are discussed. METHODS: Retrospective data from two patients with diplopic AVFs are examined with a review of all published cases of diploic arteriovenous fistulas. RESULTS: Where previously reported diploic AVFs showed venous drainage to be intracranial or combined, two case studies examined by the authors found exclusively extracranial drainage in the AVFs. In both case studies the lesions were primarily fed by the middle meningeal artery and treated via a transarterial endovascular approach using n-BCA glue. CONCLUSIONS: After reviewing all reported cases of AVF in the literature and combining our two new observations, we concluded that diploic AVFs can have three types of venous outflow: draining toward dural sinuses only, toward extracranial veins only, and combining the dural and extracranial pathways.