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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lower complication rates associated with transradial versus transfemoral flow diverting stent placement

BACKGROUND

Currently, there are no large-scale studies in the neurointerventional literature comparing safety between transradial (TRA) and transfemoral (TFA) approaches for flow diversion procedures. This study aims to assess complication rates in a large multicenter registry for TRA versus TFA flow diversion.

METHODS

We retrospectively analyzed flow diversion cases for cerebral aneurysms from 14 institutions from 2010 to 2019. Pooled analysis of proportions was calculated using weighted analysis with 95% CI to account for results from multiple centers. Access site complication rate and overall complication rate were compared between the two approaches.

RESULTS

A total of 2,285 patients who underwent flow diversion were analyzed, with 134 (5.86%) treated with TRA and 2151 (94.14%) via TFA. The two groups shared similar patient and aneurysm characteristics. Crossover from TRA to TFA was documented in 12 (8.63%) patients. There were no access site complications in the TRA group. There was a significantly higher access site complication rate in the TFA cohort as compared with TRA (2.48%, 95% CI 2.40% to 2.57%, vs 0%; p=0.039). One death resulted from a femoral access site complication. The overall complications rate was also higher in the TFA group (9.02%, 95% CI 8.15% to 9.89%) compared with the TRA group (3.73%, 95% CI 3.13% to 4.28%; p=0.035).

CONCLUSION

TRA may be a safer approach for flow diversion to treat cerebral aneurysms at a wide range of locations. Both access site complication rate and overall complication rate were lower for TRA flow diversion compared with TFA in this large series.

Iatrogenic Direct Carotid-cavernous Fistula Following Mechanical Thrombectomy: A Case Report and Review of the Literature

A carotid-cavernous fistula (CCF) is an abnormal connection between the arteries and veins of the cavernous sinus. Iatrogenic CCFs have been described as potential complications following aneurysm coiling, balloon angioplasty, and transsphenoidal surgery. In this case report, we describe a rare case of an iatrogenic direct CCF following mechanical thrombectomy (MT) for acute ischemic stroke. A 78-year-old female presented to an outside hospital with a new onset of right-sided weakness and aphasia and underwent emergency MT for a left middle cerebral artery (MCA) occlusion. The procedure was complicated by iatrogenic injury to the left cavernous internal carotid artery (ICA), which resulted in a direct high-flow CCF. The patient was transferred to our hospital and the fistula was closed with transarterial coils. Ten days later, she returned with diplopia and cranial nerve VI palsy due to residual pseudoaneurysm and was treated with a flow-diverting stent. On follow-up, the patient was neurologically intact and imaging showed no residual fistula. As the frequency of MTs performed for acute ischemic stroke continues to rise, neurointerventionalists should be aware of this potential rare complication and be prepared to manage patients who develop symptomatic CCF.

Fetal radiation exposure risk in the pregnant neurointerventionalist

BACKGROUND

The prevalence of women physicians is steadily rising, but the field of neurointervention remains one of the most male-dominated subspecialties in medicine. A fear of radiation exposure, particularly during pregnancy and childbearing years, may be responsible for deterring some of the best and brightest. This is the first study to examine the amount of maternal and fetal radiation exposure during a pregnant neurointerventional fellow's training.

METHODS

We retrospectively analyzed the radiation exposure of a neurointerventional fellow prior to and during pregnancy from February 2018 to May 2019 in 758 neurointerventional cases. The collar dosimeter was used to measure overall maternal exposure and an additional fetal dosimeter was worn under two lead apron skirts to estimate fetal radiation exposure.

RESULTS

There was not a significant difference between pre- and post-pregnancy overall maternal radiation exposure as measured by the collar dosimeter (151 mrem pre-pregnancy and 105 mrem during pregnancy, p=0.129). Mean fluoroscopy time and fluoroscopy emission per procedure also did not differ prior to and during pregnancy. Fetal radiation exposure measurements from both the Mirion Genesis Ultra TLD dosimeter as well as the Mirion Instadose dosimeters worn under double lead apron skirts were 0 mrem for all 6 months.

CONCLUSION

These findings suggest that, when optimal radiation safety practices are implemented, the fetal dose of a pregnant neurointerventionalist is negligible. Further studies and education are necessary to encourage women to choose neurointervention and allow practicing women neurointerventionalists to maintain their productivity during their reproductive years.

Treatment and diagnosis of cerebral aneurysms in the post-International Subarachnoid Aneurysm Trial (ISAT) era: trends and outcomes

BACKGROUND

Following publication of the International Subarachnoid Aneurysm Trial (ISAT), treatment paradigms for cerebral aneurysms (CAs) shifted from open surgical clipping to endovascular embolization as primary therapy in a majority of cases. However, comprehensive analyses evaluating more recent CA diagnosis patterns, patient populations and outcomes as a function of treatment modality remain rare.

METHODS

The National Inpatient Sample from 2004 to 2014 was reviewed. Aneurysmal subarachnoid hemorrhages (aSAHs) and unruptured intracranial aneurysms (UIAs) with a treatment of surgical clipping or endovascular therapy (EVT) were identified. Time trend series plots were created. Linear and logistic regressions were utilized to quantify treatment changes.

RESULTS

114 137 aSAHs and 122 916 UIAs were reviewed. aSAH (+732/year, p=0.014) and UIA (+2550/year, p<0.0001) discharges increased annually. The annual caseload of surgical clippings for aSAH decreased (-264/year, p=0.0002) while EVT increased (+366/year, p=0.0003). For UIAs, the annual caseload for surgical clipping remained stable but increased for EVT (+615/year, p<0.0001). The rate of incidentally diagnosed UIAs increased annually (+1987/year; p<0.0001). Inpatient mortality decreased for clipping (p<0.0001) and EVT in aSAH (p<0.0001) (2004 vs 2014-clipping 13% vs 11.7%, EVT 15.8% vs 12.7%). Mortality rates for clipped UIAs decreased over time (p<0.0001) and remained stable for EVT (2004 vs 2014-clipping 1.57% vs 0.40%, EVT 0.59% vs 0.52%).

CONCLUSION

Ruptured and unruptured CAs are increasingly being treated with EVT over clipping. Incidental unruptured aneurysm diagnoses are increasing dramatically. Mortality rates of ruptured aneurysms are improving regardless of treatment modality, whereas mortality in unruptured aneurysms is only improving for surgical clipping.

Advances in 3D angiography for spinal vascular malformations

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

Left transradial access for cerebral angiography

Introduction

Transradial access is increasingly used among neurointerventionalists as an alternative to the transfemoral route. Currently available data, building on the interventional cardiology experience, primarily focus on right radial access. However, there are clinical scenarios when left-sided access may be indicated. The purpose of this study was to evaluate the technical feasibility of left transradial access to cerebral angiography across three institutions.

Methods

A retrospective chart review was performed for patients who underwent cerebral angiography accessed via the left radial artery at three institutions between January 2018 and July 2019. The outcome variables studied were successful catheterization, vascular complications, and fluoroscopic time.

Results

Nineteen patients underwent a total of 25 cerebral angiograms via left transradial access for cerebral aneurysms (n=15), basilar occlusion (n=1), carotid stenosis (n=1), arteriovenous malformation (n=1), and cervical neurofibroma (n=1). There were 12 diagnostic angiograms and 13 interventional angiograms. The left transradial approach was chosen due to left vertebrobasilar pathology (n=22), right subclavian stenosis (n=2), and previous right arm amputation (n=1). There was one instance of radial artery spasm, which resolved after catheter removal, and one conversion to transfemoral access in an interventional case due to lack of distal catheter support. There were no procedural complications.

Conclusions

Left transradial access in diagnostic and interventional cerebral angiography is a technically feasible, safe, and an effective alternative when indicated, and may be preferable for situations in which pathology locations or anatomic limitations preclude right-sided radial access.

Feasibility of repeat transradial access for neuroendovascular procedures

Introduction

Transradial artery access (TRA) for cerebrovascular angiography is increasing due to decreased access site complications and overwhelming patient preference. While interventional cardiologists have reported up to 10 successive TRA procedures via the same radial access site, this is the first study examining successive use of the same artery for repeat procedures in neurointerventional procedures.1

Methods

We reviewed our prospective institutional database for all patients who underwent a transradial neurointerventional procedure between 2015 and 2019. Index procedures were defined as procedures performed via TRA after which there was a second TRA procedure attempted. Reasons for conversion to a transfemoral approach (TFA) for subsequent procedures were identified.

Results

104 patients underwent 237 procedures (230 TRA, 7 TFA). 97 patients underwent ≥2 TRA procedures, 20 patients >3, four patients >4, three patients >5, and two patients >6 TRA procedures. The success rate was 94.7% (126/133) with 52% (66/126) of successive procedures performed via the same radial access site (snuffbox vs antebrachial) while the alternate radial artery segment was used for access in 48% (60/126) of subsequent procedures. There were seven (5.3%) cases requiring crossover to TFA, six cases for radial artery occlusion (RAO) and one for radial artery narrowing.

Conclusion

Successive TRA is both technically feasible and safe for neuroendovascular procedures in up to six procedures. The low failure rate (5.3%) was primarily due to RAO. Thus, even without clinical consequences, strategies to minimize RAO should be optimized for patients to continue to benefit from TRA in future procedures.

Transradial access for neurointerventions: management of access challenges and complications

Background

Numerous large randomized trials have shown a significant morbidity and mortality benefit with the transradial approach (TRA) over the transfemoral approach (TFA) for endovascular procedures. However, this technique is routinely avoided or aborted due to unfamiliarity with the technique and the associated anatomical difficulties that may be faced in this approach. The objective of this review is to identify both the common and uncommon challenges that may be encountered during a transradial approach for cerebrovascular catheterization and to provide tips and tricks to overcome the transradial learning curve.

Method

A careful review of the literature and of all our transradial cases was carried out to identify the common challenges and complications that are encountered when using TRA for diagnostic cerebral angiography and neurointerventions.

Results

A stepwise approach is provided to prevent and manage common challenges including radial artery access failure, radial artery spasm, radial artery anomalies and tortuosity, radial artery occlusion, radial artery perforation and hematoma, subclavian tortuosity and anomalies, and catheter knots and kinks.

Conclusion

The ability to recognize and navigate anatomical variations and complications unique to TRA will accelerate learning, decrease unnecessary morbidity and mortality, and further advance the neurovascular field.

Intravenous Stem Cell Therapy for High-Grade Aneurysmal Subarachnoid Hemorrhage: Case Report and Literature Review

BACKGROUND

Aneurysmal subarachnoid hemorrhage (SAH) is associated with high mortality (30%-40%) and morbidity with long-term physical, neurologic, and psychological impairments; most patients present with high initial Hunt and Hess grade. In view of the great need for efficacious therapies for high-grade SAH, recent animal studies have demonstrated improved outcomes with administration of mesenchymal stem cells (MSCs) as a potential neuroregenerative strategy. We present the first case of human intravenous administration of MSCs after aneurysmal SAH.

CLINICAL PRESENTATION

An 80-year-old man presented with sudden severe headache with nausea and vomiting. Computed tomography demonstrated SAH with hydrocephalus from a ruptured basilar tip aneurysm. Initial examination of the patient showed Hunt and Hess grade 5 and World Federation of Neurosurgical Societies grade 5. The patient was treated with external ventricular drain placement and coiling of aneurysm. The patient received an infusion of intravenous bone marrow-derived allogeneic MSCs on day 3 postbleed. The patient made a better recovery than anticipated with a modified Rankin Scale score of 3 at 6 months.

CONCLUSIONS

Several studies using models of ischemic brain injury have found that administration of MSCs may improve functional neurologic recovery and decrease brain lesion volume. Although there have been limited human studies in patients with stroke, the role of stem cell therapy for aneurysmal SAH remains unclear. This is the first case of use of MSCs in a patient for treatment of aneurysmal SAH. In conjunction with the promising results in animal studies, this encouraging preliminary case report supports the need for additional clinical trials.

Distal transradial access in the anatomical snuffbox for diagnostic cerebral angiography

BACKGROUND

The transradial approach for endovascular angiography and interventional procedures is superior to the traditional transfemoral approach in several metrics, including lower access-site complication rates, higher patient satisfaction, and lower hospital costs. Interventional cardiologists have begun to adopt the distal transradial approach (dTRA) for coronary interventions as it has an improved safety profile and improved procedural ergonomics. Adaptation of dTRA for neuroendovascular procedures promises similar benefit, but requires a learning curve.

OBJECTIVE

To report the first use of dTRA for diagnostic cerebral angiography and demonstrate the feasibility and safety of a dTRA.

METHODS

A retrospective review of our prospective institutional database of consecutive cases of cerebral DSA performed via dTRA between August 2018 and December 2018 was performed. Patient demographics, procedural and radiographic metrics, and clinical data were recorded.

RESULTS

85 patients were identified with an average age of 53.8 years (range 18-82); 67 (78.8%) patients were female. 78 patients underwent successful dTRA diagnostic cerebral angiography, with a mean of five vessels catheterized and average fluoroscopy time of 12.0 min, or 2.6 min for each vessel. Seven patients required conversion to transfemoral access, with the most common reason being inability to advance the wire and radial artery spasm. There were no complications.

CONCLUSION

dTRA is associated with decreased rates of radial artery occlusion, ischemic hand events, as well as improved patient comfort, faster periprocedural management, and cost benefits. Our preliminary experience with dTRA for diagnostic cerebral angiography demonstrates excellent feasibility and safety in combination with relative efficiency.

Efficacy of antiseizure prophylaxis in chronic subdural hematoma: a cohort study on routinely collected health data

OBJECTIVE

Chronic subdural hematoma (CSDH) is a common neurosurgical condition that can result in significant morbidity. The incidence of epileptic events associated with CSDH reported in the literature varies considerably and could potentially increase morbidity and mortality rates. The effectiveness of antiepileptic prophylaxis for this indication remains unclear. The primary objective of this study was to assess the relevance of anticonvulsant prophylaxis in reducing seizure events in patients with CSDH.

METHODS

All consecutive cases of CSDH from January 1, 2005, to May 30, 2014, at the Hôpital de l'Enfant-Jésus in Quebec City were retrospectively reviewed. Sociodemographic data, antiepileptic prophylaxis use, incidence of ictal events, and clinical and radiological outcome data were collected. Univariate analyses were done to measure the effect of antiepileptic prophylaxis on ictal events and to identify potential confounding factors. Multivariate logistic regression was performed to evaluate factors associated with epileptic events.

RESULTS

Antiepileptic prophylaxis was administered in 28% of the patients, and seizures occurred in 11%. Univariate analyses showed an increase in the incidence of ictal events in patients receiving prophylaxis (OR 5.92). Four factors were identified as being associated with seizures: septations inside the hematoma, membranectomy, antiepileptic prophylaxis, and a new deficit postoperatively. Antiepileptic prophylaxis was not associated with seizures in multivariate analyses.

CONCLUSIONS

Antiepileptic prophylaxis does not seem to be effective in preventing seizures in patients with CSDH. However, due to the design of this study, it is difficult to conclude definitively about the usefulness of this prophylactic therapy that is widely prescribed for this condition.

Distal Radial Artery Access in the Anatomical Snuffbox for Neurointerventions: Case Report

BACKGROUND

The distal transradial approach (dTRA) is being widely adopted by interventional cardiologists, primarily owing to reduced morbidity and mortality from access site complications. The distal radial artery has advantages over standard radial access in relation to procedural positioning and radial artery preservation, particularly in patients who may require multiple angiograms. One disadvantage is the smaller diameter of the artery with more challenging puncture of a smaller, weaker artery. We demonstrate the feasibility of dTRA in 2 patients who underwent successful diagnostic angiography and mechanical thrombectomy.

CASE DESCRIPTION

Two patients underwent dTRA for neurointerventions. In patient 1, a 5-F Glidesheath Slender and a Sim2 catheter were used for a 6-vessel cerebral angiogram. In patient 2, an 0.88-inch sheathless guide catheter was used to perform a mechanical thrombectomy. Successful hemostasis in both cases was achieved with a Safeguard Radial Compression Device; no complications were observed.

CONCLUSIONS

Neurovascular access via dTRA is feasible, and further exploration is warranted.