Longitudinal Pulse-Synchronous Bouncing During Catheter Angiography-A Phenomenon Specific to Spinal Hemangioblastomas

BACKGROUND

Spinal hemangioblastomas are often evaluated with catheter angiography for both workup and treatment planning. We report a unique longitudinal pulse-synchronous bouncing phenomenon observed during their angiographic evaluation and consider the association of pulse-synchronous bouncing with syringomyelia, another pathologic feature associated with hemangioblastomas.

METHODS

Preoperative spinal angiograms and associated magnetic resonance imagings (MRIs) obtained over a 16-year period at a single institution were retrospectively evaluated. Magnetic resonance imaging (MRI) parameters included lesion and syrinx location and size. Angiograms were evaluated for bouncing phenomena. Student's t-test and Chi square test compared characteristics between groups. Linear regression analyses evaluated maximum amplitude of dynamic motion and any associated syrinx.

RESULTS

Nineteen hemangioblastoma patients had preoperative angiograms available for review. Eight exhibited bouncing behavior. Between the dynamic and nondynamic cohorts, there was no difference in presence or volume of syrinxes. Lesions in the dynamic cohort trended towards a cervical location (75% vs. 36.3%, P = 0.10). No significant correlation was found between bouncing amplitude and syrinx size (R2 = 0.023). Dural contact may be related to this dynamic behavior since other high-flow lesions like AVMs do not demonstrate this phenomenon, and AVMs are pial-based and more likely to contact stationary dura. Here, there were fewer lesions abutting the thecal sac in the dynamic cohort (50% vs. 81.8%, P = 0.14).

CONCLUSIONS

Though no significant relationship was established between this bouncing behavior and syrinx formation, noted trends included a greater range of motion for cervical lesions and limited motion in tumors abutting the thecal sac.

Clinically Asymptomatic Hemorrhagic Conversion Is Associated with Need for Inpatient Rehabilitation After Mechanical Thrombectomy for Anterior Circulation Ischemic Stroke

BACKGROUND

Hemorrhagic conversion (HC) is a known complication after acute ischemic stroke (AIS) in patients undergoing mechanical thrombectomy (MT). Although symptomatic HC has been shown to lead to poor neurologic outcomes, the effect of asymptomatic HC (aHC) is unclear. This study aims to identify predictors of aHC and to determine the short-term outcomes.

METHODS

This is a single-institution retrospective study of patients with anterior circulation stroke (AIS) who underwent MT between January 2016 and September 2022. Radiographic HC was identified on postoperative imaging. Asymptomatic hemorrhage was defined as no acute neurologic decline attributable to imaging findings. Baseline characteristics, technical aspects, and outcomes were compared between aHC and no-HC groups. Logistic regression and multivariate analysis were performed.

RESULTS

A total of 615 patients underwent MT for AIS, of whom 496 met the inclusion criteria. A total of 235 patients (47.4%) had evidence of aHC. Diabetes mellitus (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.06-2.41; P = 0.03), hyperglycemia (OR, 1.01; 95% CI, 1.00-1.01; P = 0.002), greater number of passes (OR, 1.14; 95% CI, 1.00-1.31; P = 0.05), and longer time to reperfusion (OR, 1.02; 95% CI, 1.00-1.05; P = 0.05) were associated with aHC. Patients with aHC were significantly more likely to require rehabilitation, whereas those without HC were more likely to be discharged home (P < 0.001). There were no significant differences in long-term outcomes.

CONCLUSIONS

HC occurred in up to half of patients who underwent MT for AIS, most of whom were clinically asymptomatic. Despite clinical stability, aHC was significantly associated with a greater need for inpatient rehabilitation. Predictors of aHC included hyperglycemia and a longer time to reperfusion.

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.

Racial disparities in functional outcomes following mechanical thrombectomy in a cohort of patients with ischemic stroke

BACKGROUND

Non-Hispanic Black (NHB) patients experience increased prevalence of stroke risk factors and stroke incidence compared with non-Hispanic White (NHW) patients. However, little is known about >90-day post-stroke functional outcomes following mechanical thrombectomy.

OBJECTIVE

To describe patient characteristics, evaluate stroke risk factors, and analyze the adjusted impact of race on long-term functional outcomes to better identify and limit sources of disparity in post-stroke care.

METHODS

We retrospectively reviewed 326 patients with ischemic stroke who underwent thrombectomy at two centers between 2019 and 2022. Race was self-reported as NHB, NHW, or non-Hispanic Other. Stroke risk factors, insurance status, procedural parameters, and post-stroke functional outcomes were collected. Good outcomes were defined as modified Rankin Scale score ≤2 and/or discharge disposition to home/self-care. To assess the impact of race on outcomes at 3-, 6-, and 12-months' follow-up, we performed univariate and multivariate logistic regression.

RESULTS

Patients self-identified as NHB (42%), NHW (53%), or Other (5%). 177 (54.3%) patients were female; the median (IQR) age was 67.5 (59-77) years. The median (IQR) National Institutes of Health Stroke Scale score was 15 (10-20). On univariate analysis, NHB patients were more likely to have poor short- and long-term functional outcomes, which persisted on multivariate analysis as significant at 3 and 6 months but not at 12 months (3 months: OR=2.115, P=0.04; 6 months: OR=2.423, P=0.048; 12 months: OR=2.187, P=0.15). NHB patients were also more likely to be discharged to rehabilitation or hospice/death than NHW patients after adjusting for confounders (OR=1.940, P=0.04).

CONCLUSIONS

NHB patients undergoing thrombectomy for ischemic stroke experience worse 3- and 6-month functional outcomes than NHW patients after adjusting for confounders. Interestingly, this disparity was not detected at 12 months. Future research should focus on identifying social determinants in the short-term post-stroke recovery period to improve parity in stroke care.

Classification and Management Considerations for Intraosseous Dural Arteriovenous Fistulae

BACKGROUND

Intraosseous dural arteriovenous fistulas (IODAVFs) are rare DAVFs that communicate with marrow. Given their infrequency, common nomenclature is nonexistent. Patients may present with benign symptoms, such as tinnitus, or venous hypertension symptoms including hemorrhage depending on the venous outflow pattern.

OBJECTIVE

To describe all available cases of IODAVF in the literature, in addition to our cases, to better define presentation, and treatment outcomes. To advance a classification system to develop common language for these lesions for clinicians and researchers.

METHODS

Neurointerventional procedure logs at 2 high-volume neurovascular centers were reviewed for all cases of IODAVFs, as was the English-based literature available in PubMed. The angioarchitecture, symptoms, management, and demographics were reviewed and summarized.

RESULTS

Four institutional cases were identified, 2 of which had shunting within the marrow (clival or petrous), with venous drainage toward the heart. One case involved the dorsum sella with drainage into the superior petrosal sinus with reflux into the anterior and posterior spinal venous plexuses, and one involved the left petroclival junction, resulting in communication with the cavernous sinus with retrograde drainage into the superior ophthalmic veins. Two patients were managed by observation, one was treated with radiosurgery and one with microsurgical skeletonization. Twenty additional cases from the literature are summarized.

CONCLUSION

IODAVFs of the cerebrocranial vasculature may present incidentally, with tinnitus, or with symptoms related to mass effect or venous hypertension. We propose a classification which accounts for drainage patterns. Further study is needed for these rare lesions.

The segmentation of the vertebral artery: An ambiguous anatomical concept

The course of the vertebral artery from its subclavian artery origin up to its termination at the vertebrobasilar junction is divided into four segments (V1-V4). This segmentation, based on schemes that have evolved since the late nineteenth century, should be a consistent and reproducible anatomical concept. However, the current literature offers conflicting definitions of that scheme, not infrequently within a single article or monograph. The principal inconsistency found in modern publications concerns the termination of the V2 segment, which is either set at the C2 or C1 transverse foramen depending on the scheme considered. Consequently, the portion of the vertebral artery extending between C2 and C1-a frequent site of pathological involvement-either belongs to the V2 or V3 segment. This discrepancy can affect the validity of studies evaluating the diagnosis and management of vertebral artery disorders. A V3 segment extending from the transverse foramen of C2 to the posterior atlanto-occipital membrane and subdivided into vertical, horizontal, and oblique subsegments-a pattern suggested by Barbieri in 1867 and adopted in some modern publications-would provide a simple, precise, and reliable solution without significantly altering the widely accepted division of the vertebral artery into four segments (V1-V4).

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.

Epidemiology and outcomes of pediatric intracranial aneurysms: comparison with an adult population in a 30-year, prospective database

OBJECTIVE

Pediatric intracranial aneurysms are rare. Most large series in the last 15 years reported on an average of only 39 patients. The authors sought to report their institutional experience with pediatric intracranial aneurysms from 1991 to 2021 and to compare pediatric patient and aneurysm characteristics with those of a contemporaneous adult cohort.

METHODS

Pediatric (≤ 18 years of age) and adult patients with one or more intracranial aneurysms were identified in a prospective database. Standard epidemiological features and outcomes of each pediatric patient were retrospectively recorded. These results were compared with those of adult aneurysm patients managed at a single institution over the same time period.

RESULTS

From a total of 4500 patients with 5150 intracranial aneurysms admitted over 30 years, there were 47 children with 53 aneurysms and 4453 adults with 5097 aneurysms; 53.2% of children and 36.4% of adults presented with a subarachnoid hemorrhage (SAH). Pediatric aneurysms were significantly more common in males, more likely giant (≥ 25 mm), and most frequently located in the middle cerebral artery. Overall, 85.1% of the pediatric patients had a modified Rankin Scale score ≤ 2 at the last follow-up (with a mean follow-up of 65.9 months), and the pediatric mortality rate was 10.6%; all 5 patients who died had an SAH. The recurrence rate of treated aneurysms was 6.7% (1/15) in the endovascular group but 0% (0/31) in the microsurgical group. No de novo aneurysms occurred in children (mean follow-up 5.5 years).

CONCLUSIONS

Pediatric intracranial aneurysms are significantly different from adult aneurysms in terms of sex, presentation, location, size, and outcomes. Future prospective studies will better characterize long-term aneurysm recurrence, rebleeds, and de novo aneurysm occurrences. The authors currently favor microsurgical over endovascular treatment for pediatric aneurysms.

Endovascular therapy for acute stroke in children: age and size technical limitations

Endovascular therapies for acute childhood stroke remain controversial and little evidence exists to determine the minimum age and size cut-off for thrombectomy in children. Despite this, an increasing number of reports suggest feasibility of thrombectomy in at least some children by experienced operators. When compared with adults, technical modifications may be necessary in children owing to differences in vessel sizes, tolerance of blood loss, safety of contrast and radiation exposure, and differing stroke etiologies. We review critical considerations for neurologists and neurointerventionalists when treating pediatric stroke with endovascular therapies. We discuss technical factors that may limit feasibility of endovascular therapy, including size of the femoral and cervicocerebral arteries, which contributes to vasospasm risk. The risk of femoral vasospasm can be assessed by comparing catheter outer diameter with estimated femoral artery size, which can be estimated based on the child's height. We review evidence supporting specific strategies to mitigate cervicocerebral arterial injury, including technique (stent retrieval vs direct aspiration) and device size selection. The importance of and strategies for minimizing blood loss, radiation exposure, and contrast administration are reviewed. Attention to these technical limitations is critical to delivering the safest possible care when thrombectomy is being considered for children with acute stroke.

Report of a spinal extradural arteriovenous fistula with double radiculomedullary venous drainage: therapeutic implications and role of intraoperative spinal angiography

Low-flow spinal extradural arteriovenous fistulas (SEAVFs) are frequently misdiagnosed as spinal dural arteriovenous fistulas (SDAVFs), and their true prevalence is unknown. The principal feature distinguishing low-flow SEAVFs from SDAVFs is the location of the shunt, which involves a pouch of epidural plexus in SEAVFs and a radiculomedullary vein (RMV) in SDAVFs. A venous hypertensive myelopathy comparable to the one observed with SDAVFs develops when the arterialized venous pouch of an SEAVF is connected to an RMV. Depending on the size of the epidural pouch, a low-flow SEAVF may uncommonly drain into multiple RMVs. The authors present an observation of a low-flow SEAVF whose double radiculomedullary drainage was revealed only after intraoperative digital subtraction angiography, and they discuss the surgical implications of this anatomical configuration.

Neurovascular anatomy: Spine

The arterial supply of the spinal cord is provided by the spinal branch of the cervical, thoracic, and lumbar intersegmental arteries. While supply is initially provided at each embryonic segment, only a few prominent anterior radiculomedullary arteries remain at the adult stage, including the arteries of the cervical and lumbosacral enlargements as well as a constant upper thoracic contributor. The spinal cord is surrounded by the vasocorona, an arterial network that includes several longitudinal anastomotic chains, notably the anterior and posterior spinal arteries, which respectively supply the central and peripheral components of the intrinsic vascularization. The intrinsic venous circulation is also divided into central and peripheral components. The perimedullary venous system includes several longitudinal anastomotic chains interconnected by the coronary plexus. The radiculomedullary veins loosely follow the spinal nerve roots on their way to the epidural plexus. Their point of passage through the thecal sac forms an important valve-like structure, the antireflux mechanism.

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.

Persistent second cervical intersegmental artery in a case of possible PHACE syndrome

The proximal segment of the vertebral artery most often consists of a persistent sixth cervical intersegmental artery that originates from the subclavian artery, but it may also derive from a fifth, fourth, or third cervical intersegmental artery (in decreasing order of frequency), or from a first thoracic intersegmental artery. The involvement of more cranial cervical branches is exceptional, with no known persistent first cervical intersegmental artery and possibly five cases of persistent second cervical intersegmental arteries reported so far. This report describes a patient with multiple arterial variations including right persistent second cervical intersegmental artery of common carotid origin, distal VA duplication, circumflex aortic arch, and segmental internal carotid agenesis in a context of possible PHACE syndrome.

Safety of diagnostic spinal angiography in children

BACKGROUND

Spinal angiography (SA) is associated with low complications in adults but its safety in children has not been properly analyzed. The goal of our study is to assess the safety of pediatric SA.

METHODS

This study is the retrospective analysis of a series of 36 consecutive SA procedures performed in 27 children over a 5-year period. Parameters including neurological complications, non-neurological complications requiring additional management, contrast volume, and radiation exposure were analyzed via univariate and bivariate methods.

RESULTS

Our cohort included 24 diagnostic and 12 combined therapeutic cases in children with an average age of 11.1 years. No neurological or non-neurological complication requiring additional management was recorded. The average volume of contrast administered was 1.6 mL/kg in the diagnostic group and 0.9 mL/kg in the combined group. The average air kerma was 186.9mGy for an average of 36.8 exposures in the diagnostic group, and 264.5mGy for an average of 21 exposures in the combined group. Patients in the combined group had lower contrast load (45% lower on average) and higher air kerma (1.6 times higher on average). The difference in air kerma was due to a higher live fluoroscopy-related exposure.

CONCLUSIONS

This study reports the largest pediatric SA cohort analyzed to date and the only one including radiation dose and contrast load. It confirms that pediatric SA is a safe imaging modality with low risk of complications, and demonstrates that SA can be performed in children with low radiation exposure and contrast load.

The antireflux mechanism - Angiographic anatomy and clinical implications

BACKGROUND

Early anatomists suspected that the radiculomedullary veins draining the spinal cord had valves preventing their retrograde filling with anatomical casting material. Modern investigations have discarded the presence of true valves and introduced instead the notion of a pseudo-valvular configuration for which the term antireflux mechanism was coined in the 1970s. The angiographic anatomy of the antireflux mechanism has not been well documented so far.

METHODS

This article discusses anatomical and clinical features of the antireflux mechanism with a series of 12 angiographic observations documenting the antireflux mechanism under normal and pathological circumstances.

RESULTS

The antireflux mechanism divides radiculomedullary veins into intradural and extradural segments. While the structure of the antireflux mechanism is not yet fully clarified, it includes at least a tight narrowing of the radiculomedullary vein at its point of passage through the thecal sac, which is angiographically detectable and likely protects the intradural venous system from transient or persistent surges in venous pressure (e.g. sneezing, pregnancy). This tight narrowing of the antireflux mechanism likely also represents an obstacle to normal anterograde flow, potentially leading to venous stagnation and thrombosis.

CONCLUSIONS

The antireflux mechanism includes at least a tight narrowing of the radiculomedullary vein, which likely influences the development and clinical expression of low-flow spinal arteriovenous fistulas and might impact the spinal venous drainage even in the absence of arteriovenous shunts.

Mid-term assessment of transverse sinus stent patency in 104 patients treated for intracranial hypertension secondary to dural sinus stenosis

BACKGROUND

Transverse sinus (TS) stenting is a valid treatment alternative for patients with intracranial hypertension caused by underlying bilateral TS stenoses. Its mid-term patency has, however, not been well documented.

OBJECTIVE

To assess the 6-month patency of TS stenting using subtracted CT venography (CTV).

METHODS

A retrospective analysis of a prospectively collected database of patients undergoing TS stenting was performed. The cohort was a single-center, single-operator series of 125 consecutive patients treated between 2008 and 2018. Mid-term follow-up 320-row detector CTV was available for review in 104 patients.

RESULTS

Follow-up CTV was obtained on average 6 months after stenting. Stents in all patients (100%) were patent. Subtracted reconstructions showed no intraluminal thrombus or neointimal hyperplasia. Native reconstructions confirmed the structural integrity of the stents. De novo stenosis proximal to the stent was noted in 10 cases (10%). A total of 10 patients (10%) received additional treatment due to recurrent symptoms. In univariate analysis, both high body mass index and stent size (>6 mm) were associated with development of de novo stenoses: OR 1.12 (95% CI 1.01 to 1.25, p=0.037) and OR 5.63 (95% CI 1.16 to 27.22, p=0.032), respectively. In multivariate analysis, only stent size (>6 mm) remained significant: OR 7.19 (95% CI 1.03 to 50.01, p=0.046).

CONCLUSION

TS stenting is an effective treatment for intracranial hypertension secondary to dural sinus stenosis in an appropriately selected patient population. A 320-row dynamic CTV is a high-quality non-invasive imaging method that can assess both the physical integrity of the stent and its patency. At mid-term follow-up, all imaged stents were patent. The occurrence of de novo stenoses proximal to the stent (10%) correlated with stent size (>6 mm).

Case of Cowden Syndrome with 15 Spinal Arteriovenous Fistulas

BACKGROUND

Spinal vascular malformations are rarely multiple: fewer than 50 observations have been documented so far, with a maximum of 4 coexisting lesions per patient, always restricted to a single vertebral region (e.g., cervical or thoracic).

CASE DESCRIPTION

We describe the case of a 61-year-old woman with Cowden syndrome with 15 spinal arteriovenous fistulas (AVFs) at the cervical, thoracic, and lumbar levels and an adrenal AVF. She was initially referred for reevaluation of an upper cervical spinal epidural spinal arteriovenous fistula diagnosed 6 years earlier. Her history included breast carcinoma, a malignant salivary gland tumor, and removal of multiple ovarian, thyroid, and gastric hamartomas. Computed tomography and magnetic resonance imaging confirmed the presence of a prominent cervical vascular lesion. Spinal digital subtraction angiography revealed the presence of 15 additional vascular anomalies.

CONCLUSIONS

This multiplicity of AVFs appears to result from a combination of various factors including local regional hemodynamic changes, growth factor-mediated alterations involving notably vascular endothelial growth factor pathways, and the prothrombotic state associated with abnormalities in blood vessel structure.

Vertebral Artery Sacrifice versus Skeletonization in the Setting of Cervical Spine Tumor Resection: Case Series

OBJECTIVE

Tumors of the cervical spine often encase 1 or both vertebral arteries (VA), presenting the treating surgeon with the dilemma of whether to sacrifice or skeletonize the artery. We propose an algorithm for VA management in surgeries for cervical neoplasms METHODS: A retrospective review was carried out of 67 patients undergoing resection of cervical spine tumors with VA involvement. Patients were categorized by tumor origin (primary vs. metastatic) and degree of circumferential VA involvement: 1) abutment only; 2) <180° circumferential involvement; 3) >180° circumferential involvement without complete encasement; or 4) complete encasement.

RESULTS

Twelve patients (18%) underwent VA sacrifice, whereas 55 (82%) underwent VA skeletonization. Compared with 11/30 patients with primary tumors (37%), only 1/37 patients (3%) with metastatic disease underwent VA sacrifice (P < 0.01). This patient had invasion of the V2 arterial wall, requiring VA sacrifice. Odds of VA sacrifice also increased with increasing circumferential involvement (P < 0.01). No patients with simple abutment or 0°-180° circumferential involvement underwent sacrifice, whereas 6 of 10 (60%) with 180°-359° involvement and 6 of 29 (21%) with complete encasement underwent VA sacrifice. Of the 27 patients with ≥180° involvement, the reasons for preserving the VA were metastatic disease at the time of treatment (n = 18), a compromised contralateral VA (n = 7), vertebrobasilar junction aplasia (n = 1), and presence of a radiculomedullary artery at the affected level (n = 1).

CONCLUSIONS

Primary tumor disease and >180° of circumferential VA involvement should be considered as indications for intraoperative sacrifice of the VA pending preoperative angiographic evaluation for contraindications.

Comparison of complete and near-complete endovascular embolization of hypervascular spine tumors with partial embolization

OBJECTIVE

Preoperative endovascular embolization of hypervascular spine tumors can reduce intraoperative blood loss. The extent to which subtotal embolization reduces blood loss has not been clearly established. This study aimed to elucidate a relationship between the extent of preoperative embolization and intraoperative blood loss.

METHODS

Sixty-six patients undergoing preoperative endovascular embolization and subsequent resection of hypervascular spine tumors were retrospectively reviewed. Patients were divided into 3 groups: complete embolization (n = 22), near-complete embolization (≥ 90% but < 100%; n = 22), and partial embolization (< 90%; n = 22). Intraoperative blood loss was compared between groups using one-way ANOVA with post hoc comparisons between groups.

RESULTS

The average blood loss in the complete embolization group was 1625 mL. The near-complete embolization group had an average blood loss of 2021 mL in surgery. Partial embolization was associated with a mean blood loss of 4009 mL. On one-way ANOVA, significant differences were seen across groups (F-ratio = 6.81, p = 0.002). Significant differences in intraoperative blood loss were also seen between patients undergoing complete and partial embolization (p = 0.001) and those undergoing near-complete and partial embolization (p = 0.006). Pairwise testing showed no significant difference between complete and near-complete embolization (p = 0.57). Analysis of a combined group of complete and near-complete embolization also showed a significantly decreased blood loss compared with partial embolization (p < 0.001). Patient age, tumor size, preoperative coagulation parameters, and preoperative platelet count were not significantly associated with blood loss.

CONCLUSIONS

Preoperative endovascular embolization is associated with decreased intraoperative blood loss. In this series, blood loss was significantly less in surgeries for tumors in which preoperative complete or near-complete embolization was achieved than in tumors in which preoperative embolization resulted in less than 90% reduction of tumor vascular blush. These findings suggest that there may be a critical threshold of efficacy that should be the goal of preoperative embolization.

Retroperitoneal approach for the treatment of diaphragmatic crus syndrome: technical note

OBJECTIVE

Myelopathy selectively involving the lower extremities can occur secondary to spondylotic changes, tumor, vascular malformations, or thoracolumbar cord ischemia. Vascular causes of myelopathy are rarely described. An uncommon etiology within this category is diaphragmatic crus syndrome, in which compression of an intersegmental artery supplying the cord leads to myelopathy. The authors present the operative technique for treating this syndrome, describing their experience with 3 patients treated for acute-onset lower-extremity myelopathy secondary to hypoperfusion of the anterior spinal artery.

METHODS

All patients had compression of a lumbar intersegmental artery supplying the cord; the compression was caused by the diaphragmatic crus. Compression of the intersegmental artery was probably producing the patients' symptoms by decreasing blood flow through the artery of Adamkiewicz, causing lumbosacral ischemia.

RESULTS

All patients underwent surgery to transect the offending diaphragmatic crus. Each patient experienced substantial symptom improvement, and 2 patients made a full neurological recovery before discharge.

CONCLUSIONS

Diaphragmatic crus syndrome is a rare or under-recognized cause of ischemic myelopathy. Patients present with episodic acute-on-chronic lower-extremity paraparesis, gait instability, and numbness. Angiography confirms compression of an intersegmental artery that gives rise to a dominant radiculomedullary artery. Transecting the offending diaphragmatic crus can produce complete resolution of neurological symptoms.

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.

Isolated superior striate vein thrombosis in adults

BACKGROUND

Isolated cerebral deep medullary vein thrombosis has been described in the setting of hemorrhagic periventricular white matter lesions in preterm and full-term neonates, but to the best of our knowledge, has never been reported in adults. We present two cases of isolated thrombosis of the superior striate vein occurring in adults that could be analogous to deep medullary vein thrombosis in that they involve deep cerebral veins only without thrombosis of the subependymal or internal cerebral veins.

CASE DESCRIPTION

Two women aged 20 and 39, presented with transient neurological deficits and headache. Diagnosis of isolated superior striate vein thrombosis was based on CT and MRI findings with long term imaging follow-up. Both patients evolved favorably under conservative treatment without anticoagulation. Thrombophilia workup was negative and both patients were active smokers under oral contraception.

CONCLUSION

Isolated superior striate vein thrombosis is a rare form of intracranial venous thrombosis and should be considered in the differential diagnosis of stroke-like episodes with headache in adults. Isolated superior striate vein thrombosis presents with characteristic imaging features on CT and MRI.

The contributions of Otto Hebold and Julius Gaupp to the study of spinal vascular malformations: Original documents and historical context

Book chapters and journal articles dealing with spinal cord vascular malformations often reference Otto Hebold and Julius Gaupp, but frequently misrepresent the observations published by the two German authors in the late 19th century. The purpose of this paper is to provide a better appreciation of these important contributions based on abridged translations of original documents set in their historical context, notably regarding the landmark works of Brasch, Raymond and Cestan, and Lindenmann. It is concluded that Gaupp offered the first reliable description of a perimedullary arteriovenous fistula while the lesion reported by Hebold was not a spinal vascular malformation.

Spinal Vascular Anatomy

This article reviews the arterial and venous anatomy of the spine and spinal cord. Special emphasis is placed on vessels critical to the conduct and interpretation of spinal angiography, notably the intersegmental artery and its cranial and caudal derivatives: the vertebral, supreme intercostal, and sacral arteries.

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.

Cervical spinal dural fistulas leading to remote thoracolumbar myelopathy: A diagnostic pitfall

Purpose of review

Spinal dural arteriovenous fistulas (SDAVFs) are abnormal connections between 1 or more radiculomeningeal arteries and a single radiculomedullary vein draining into the perimedullary venous system. SDAVFs present in older patients with a progressive myelopathy caused by diffuse spinal venous hypertension. The discrepancy between the focal nature of the arteriovenous shunt and the extent of the induced myelopathy is a classic feature of SDAVFs related to the coexistence of diffuse spinal venous drainage impairment.

Recent findings

We describe 3 cases of cervical SDAVFs (at C1, C4, and C7) presenting with a myelopathy that spared the cervical spinal cord and, in 2 instances, the upper thoracic cord. This is to our knowledge the first observations of cervical SDAVFs with MRI showing absent or subtle flow voids and presenting remote thoracolumbar myelopathy without cervical cord involvement.

Summary

A considerable distance may separate low-flow spinal arteriovenous fistulas from the spinal cord damage they produce. These observations emphasize the importance of performing a complete spinal angiogram when investigating a vascular myelopathy of any location and extent.

The Occipital Emissary Vein: A Possible Marker for Pseudotumor Cerebri

BACKGROUND AND PURPOSE

Transverse sinus stenosis can lead to pseudotumor cerebri syndrome by elevating the cerebral venous pressure. The occipital emissary vein is an inconstant emissary vein that connects the torcular herophili with the suboccipital veins of the external vertebral plexus. This retrospective study compares the prevalence and size of the occipital emissary vein in patients with pseudotumor cerebri syndrome with those in healthy control subjects to determine whether the occipital emissary vein could represent a marker of pseudotumor cerebri syndrome.

MATERIALS AND METHODS

The cranial venous system of 46 adult patients with pseudotumor cerebri syndrome (group 1) was studied on CT venography images and compared with a group of 92 consecutive adult patients without pseudotumor cerebri syndrome who underwent venous assessment with gadolinium-enhanced 3D-T1 MPRAGE sequences (group 2). The presence of an occipital emissary vein was assessed, and its proximal (intraosseous) and distal (extracranial) maximum diameters were measured and compared between the 2 groups. Seventeen patients who underwent transverse sinus stent placement had their occipital emissary vein diameters measured before and after stent placement.

RESULTS

Thirty of 46 (65%) patients in group 1 versus 29/92 (31.5%) patients in group 2 had an occipital emissary vein (P < .001). The average proximal and distal occipital emissary vein maximum diameters were significantly larger in group 1 (2.3 versus 1.6 mm, P <.005 and 3.3 versus 2.3 mm, P < .001). The average maximum diameters of the occipital emissary vein for patients who underwent transverse sinus stent placement were larger before stent placement than after stent placement: 2.6 versus 1.8 mm proximally (P < .06) and 3.7 versus 2.6 mm distally (P < .005).

CONCLUSIONS

Occipital emissary veins are more frequent and larger in patients with pseudotumor cerebri syndrome than in healthy subjects, a finding consistent with their role as collateral venous pathway in transverse sinus stenosis. A prominent occipital emissary vein is an imaging sign that should raise the suspicion of pseudotumor cerebri syndrome.

Atypical Vertebral Hemangiomas Are Frequently Associated with Radiculomedullary Arteries

BACKGROUND

Preoperative endovascular embolization of atypical hemangiomas of the spine can reduce intraoperative blood loss. One frequent concern raised about embolizing these tumors is a possible association with arteries feeding the spinal cord, such as the artery of Adamkiewicz. This study aimed to elucidate a relationship between spinal levels affected by atypical spinal hemangiomas and radiculomedullary arteries.

METHODS

This was a retrospective review of 8 patients undergoing preoperative embolization of atypical spinal hemangiomas. We evaluated 54 spinal levels by angiography during embolization procedures. Each spinal level was categorized on the basis of the presence or absence of tumor and radiculomedullary artery.

RESULTS

Six of 15 (40%) affected levels had an associated radiculomedullary artery. Four of 39 (10.2%) unaffected levels had an associated cord feeding artery. The relative risk of affected spinal levels having an associated radiculomedullary artery was 3.9 (95% confidence interval 1.28-11.91). The attributable risk was 0.40 (95% CI 0.12-0.76). The chi-squared statistic was 6.35, with a P value of 0.01. Six of 8 patients (75%) had a radiculomedullary artery at a level of disease and embolization.

CONCLUSIONS

In this study, spinal levels affected by atypical hemangiomas requiring surgery were associated with radiculomedullary arteries. When performing preoperative embolization, great care must be taken to identify and preserve arteries supplying the spinal cord.

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.

Image guided percutaneous spine procedures using an optical see-through head mounted display: proof of concept and rationale

BACKGROUND AND PURPOSE

Optical see-through head mounted displays (OST-HMDs) offer a mixed reality (MixR) experience with unhindered procedural site visualization during procedures using high resolution radiographic imaging. This technical note describes our preliminary experience with percutaneous spine procedures utilizing OST-HMD as an alternative to traditional angiography suite monitors.

METHODS

MixR visualization was achieved using the Microsoft HoloLens system. Various spine procedures (vertebroplasty, kyphoplasty, and percutaneous discectomy) were performed on a lumbar spine phantom with commercially available devices. The HMD created a real time MixR environment by superimposing virtual posteroanterior and lateral views onto the interventionalist's field of view. The procedures were filmed from the operator's perspective. Videos were reviewed to assess whether key anatomic landmarks and materials were reliably visualized. Dosimetry and procedural times were recorded. The operator completed a questionnaire following each procedure, detailing benefits, limitations, and visualization mode preferences.

RESULTS

Percutaneous vertebroplasty, kyphoplasty, and discectomy procedures were successfully performed using OST-HMD image guidance on a lumbar spine phantom. Dosimetry and procedural time compared favorably with typical procedural times. Conventional and MixR visualization modes were equally effective in providing image guidance, with key anatomic landmarks and materials reliably visualized.

CONCLUSION

This preliminary study demonstrates the feasibility of utilizing OST-HMDs for image guidance in interventional spine procedures. This novel visualization approach may serve as a valuable adjunct tool during minimally invasive percutaneous spine treatment.

Treatment of hemorrhagic head and neck lesions by direct puncture and n-BCA embolization

Life-threatening bleeding in the head and neck region requires urgent management. These hemorrhagic lesions, for example, a ruptured pseudoaneurysm, are often treated by transarterial embolization (TAE), but prior intervention or surgery, inflammation, anatomic variants, and vessel tortuosity may render an endovascular approach challenging, time-consuming, and sometimes impossible. We report two cases of severe head and neck hemorrhages successfully embolized with n-butyl cyanoacrylate via direct puncture, and propose this approach as a fast, safe, and effective alternative to TAE.

Acute progressive paraplegia in heroin-associated myelopathy

As the opioid epidemic continues, understanding manifestations of abuse, including heroin-associated myelopathy remains essential. Here we describe a young man with a past medical history significant for polysubstance abuse who developed acute-onset, rapidly progressive myelopathy after resumption of intravenous heroin use. He had significant spinal cord involvement with findings suggestive of heroin-associated myelopathy. The salient features of this case include diffusion imaging of the spine and spinal angiography supporting a possible vasculopathy as the pathophysiologic mechanism underlying heroin-associated myelopathy. Additionally, CSF studies showed the transition from a neutrophilic pleocytosis to a lymphocytic pleocytosis suggesting an inflammatory component.

A longitudinally extensive myelopathy associated with multiple spinal arteriovenous fistulas in a patient with Cowden syndrome: a case report

BACKGROUND CONTEXT

Cowden syndrome is an autosomal dominant syndrome characterized by multiple hamartomas and an increased cancer risk. It is associated with mutations in the phosphatase and tensin homologue (PTEN) gene that encodes a tumor suppressant phosphatase.

PURPOSE

The study aimed to report an unusual case of multiple spinal epidural arteriovenous fistulas in a patient diagnosed with Cowden syndrome.

STUDY DESIGN

This is a case report.

PATIENT SAMPLE

The patient is a 57-year-old woman.

METHODS

We report the case of a 57-year-old woman with a history of multiple cancers, with acute exacerbation of lower extremity weakness and numbness that had progressed over a month.

RESULTS

Magnetic resonance imaging showed abnormal signal in the thoracolumbar spinal cord, with enhancement after contrast administration. A spinal angiogram confirmed the presence of multiple spinal epidural arteriovenous fistulas. Genetic testing confirmed the diagnosis of Cowden syndrome with a mutation in intron 3 of the PTEN gene.

CONCLUSIONS

Spinal vascular malformations occur in patients with Cowden syndrome, and they can be multifocal and locally aggressive. It is important to raise the suspicion of Cowden syndrome in patients with spinal cord vascular anomalies and a history of multiple cancers, as the correct genetic diagnosis may have implications for management and cancer screening.

Clinical biomarkers differentiate myelitis from vascular and other causes of myelopathy

Objective

To assess the predictive value of the initial clinical and paraclinical features in the differentiation of inflammatory myelopathies from other causes of myelopathy in patients with initial diagnosis of transverse myelitis (TM).

Methods

We analyzed the clinical presentation, spinal cord MRI, and CSF features in a cohort of 457 patients referred to a specialized myelopathy center with the presumptive diagnosis of TM. After evaluation, the myelopathies were classified as inflammatory, ischemic/stroke, arteriovenous malformations/fistulas, spondylotic, or other. A multivariable logistic regression model was used to determine characteristics associated with the final diagnosis and predictors that would improve classification accuracy.

Results

Out of 457 patients referred as TM, only 247 (54%) were confirmed as inflammatory; the remaining 46% were diagnosed as vascular (20%), spondylotic (8%), or other myelopathy (18%). Our predictive model identified the temporal profile of symptom presentation (hyperacute <6 hours, acute 6–48 hours, subacute 48 hours–21 days, chronic >21 days), initial motor examination, and MRI lesion distribution as characteristics that improve the correct classification rate of myelopathies from 67% to 87% (multinomial area under the curve increased from 0.32 to 0.67), compared to only considering CSF pleocytosis and MRI gadolinium enhancement. Of all predictors, the temporal profile of symptoms contributed the most to the increased discriminatory power.

Conclusions

The temporal profile of symptoms serves as a clinical biomarker in the differential diagnosis of TM. The establishment of a definite diagnosis in TM requires a critical analysis of the MRI and CSF characteristics to rule out non-inflammatory causes of myelopathy.

Classification of evidence

This study provides Class IV evidence that for patients presenting with myelopathy, temporal profile of symptoms, initial motor examination, and MRI lesion distribution distinguish those with inflammatory myelopathies from those with other causes of myelopathy.

Treatment of hemorrhagic head and neck lesions by direct puncture and nBCA embolization

Life-threatening bleeding in the head and neck region requires urgent management. These hemorrhagic lesions, for example, a ruptured pseudoaneurysm, are often treated by transarterial embolization (TAE), but prior intervention or surgery, inflammation, anatomic variants, and vessel tortuosity may render an endovascular approach challenging, time-consuming, and sometimes impossible. We report two cases of severe head and neck hemorrhages successfully embolized with n-butyl cyanoacrylate via direct puncture, and propose this approach as a fast, safe, and effective alternative to TAE.

Analysis of 30 Spinal Angiograms Falsely Reported as Normal in 18 Patients with Subsequently Documented Spinal Vascular Malformations

BACKGROUND AND PURPOSE

The early diagnosis of spinal vascular malformations suffers from the nonspecificity of their clinical and radiologic presentations. Spinal angiography requires a methodical approach to offer a high diagnostic yield. The prospect of false-negative studies is particularly distressing when addressing conditions with a narrow therapeutic window. The purpose of this study was to identify factors leading to missed findings or inadequate studies in patients with spinal vascular malformations.

MATERIALS AND METHODS

The clinical records, laboratory findings, and imaging features of 18 patients with spinal arteriovenous fistulas and at least 1 prior angiogram read as normal were reviewed. The clinical status was evaluated before and after treatment by using the Aminoff-Logue Disability Scale.

RESULTS

Eighteen patients with 19 lesions underwent a total of 30 negative spinal angiograms. The lesions included 9 epidural arteriovenous fistulas, 8 dural arteriovenous fistulas, and 2 perimedullary arteriovenous fistulas. Seventeen patients underwent endovascular (11) or surgical (6) treatment, with a delay ranging between 1 week and 32 months; the Aminoff-Logue score improved in 13 (76.5%). The following factors were identified as the causes of the inadequate results: 1) lesion angiographically documented but not identified (55.6%); 2) region of interest not documented (29.6%); or 3) level investigated but injection technically inadequate (14.8%).

CONCLUSIONS

All the angiograms falsely reported as normal were caused by correctible, operator-dependent factors. The nonrecognition of documented lesions was the most common cause of error. The potential for false-negative studies should be reduced by the adoption of rigorous technical and training standards and by second opinion reviews.

Real-time MRI for precise and predictable intra-arterial stem cell delivery to the central nervous system

Stem cell therapy for neurological disorders reached a pivotal point when the efficacy of several cell types was demonstrated in small animal models. Translation of stem cell therapy is contingent upon overcoming the challenge of effective cell delivery to the human brain, which has a volume ∼1000 times larger than that of the mouse. Intra-arterial injection can achieve a broad, global, but also on-demand spatially targeted biodistribution; however, its utility has been limited by unpredictable cell destination and homing as dictated by the vascular territory, as well as by safety concerns. We show here that high-speed MRI can be used to visualize the intravascular distribution of a superparamagnetic iron oxide contrast agent and can thus be used to accurately predict the distribution of intra-arterial administered stem cells. Moreover, high-speed MRI enables the real-time visualization of cell homing, providing the opportunity for immediate intervention in the case of undesired biodistribution.

Intraforaminal Location of Thoracolumbar Radicular Arteries Providing an Anterior Radiculomedullary Artery Using Flat Panel Catheter Angiotomography

BACKGROUND AND PURPOSE

Flat panel catheter angiotomography performed during the selective injection of intersegmental arteries offers a multiplanar assessment of the intraforaminal course of the radicular arteries providing an anterior radiculomedullary artery. Injury of anterior radiculomedullary arteries during transforaminal epidural steroid injections can result in spinal cord damage. Evaluations of the intraforaminal location of these arteries have so far been limited to anteroposterior views or the examination of cadaveric material. This study documents the in vivo intraforaminal location of thoracolumbar arteries providing an anterior radiculomedullary artery with flat panel catheter angiotomography.

MATERIALS AND METHODS

Ninety-four flat panel catheter angiotomography acquisitions obtained during the selective injection of intersegmental arteries providing an anterior radiculomedullary artery were reviewed. Measurements obtained from sagittal reconstructions were converted into a scatterplot visualization. Patients' age, sex, and side and level of the injection were recorded.

RESULTS

The location of radicular arteries could be ascertained in 78 of 94 flat panel catheter angiotomography acquisitions (33 women and 45 men, 22-82 years of age). Fifty-three acquisitions (67.9%) were on the left side, and 25 (32.1%), on the right, between T2 and L3. The arteries were found in the anterosuperior quadrant of the neural foramen in 75 cases (96.2%), in the posterosuperior quadrant in 2 cases (2.6%), and in the anteroinferior quadrant in 1 case (1.3%). None were located in the posteroinferior quadrant. No differences in location were observed with age, sex, side of injection, or vertebral level.

CONCLUSIONS

Avoiding needle placement in the superior half of the neural foramen, specifically the anterosuperior quadrant, can reduce the risk of spinal cord injury during transforaminal epidural steroid injection.