Endoscopic fenestration of an enlarging giant occipital arachnoid cyst

This case demonstrates an endoscopic fenestration of an enlarging giant occipital arachnoid cyst. The patient is a 42-year-old woman presenting with headache, progressive vision loss, and nausea and vomiting. MRI demonstrates a large, nonenhancing cystic lesion in the right occipital lobe measuring up to 8.3 cm, consistent with an arachnoid cyst. This surgical video illustrates the technique for an endoscopic fenestration into the native ventricular system utilizing stereotactic MRI-guided stealth navigation. Postoperatively, the patient had full recovery with improvement of headaches and vision and was discharged on postoperative day 1 without complications.

The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22129

Highly Visible Wall-Timer to Reduce Endovascular Treatment Time for Stroke

BACKGROUND

Endovascular therapy for acute ischemic stroke has revolutionized clinical care for patients with stroke and large vessel occlusion, but treatment remains time sensitive. At our stroke center, up to half of the door-to-groin time is accounted for after the patient arrives in the angio-suite. Here, we apply the concept of a highly visible timer in the angio-suite to quantify the impact on endovascular treatment time.

METHODS

This was a single-center prospective pseudorandomized study conducted over a 32-week period. Pseudorandomization was achieved by turning the timer on and off in 2-week intervals. The primary outcome was angio-suite-to-groin time, and secondary outcomes were angio-suite-to-intubation time, groin-to-recanalization time, and 90-day modified Rankin scale. A stratified analysis was performed based on type of anesthesia (ie, endotracheal intubation versus not).

RESULTS

During the 32-week study period, 97 mechanical thrombectomies were performed. The timer was on and off for 38 and 59 cases, respectively. The timer resulted in faster angio-suite-to-groin time (28 versus 33 minutes; P=0.02). The 5-minute reduction in angio-suite-to-groin was maintained after adjusting for intubation status in a multivariate regression (P=0.02). There was no difference in the 90-day modified Rankin scale between groups. The timer impact was consistent across the 32-week study period.

CONCLUSIONS

A highly visible timer in the angio-suite achieved a meaningful, albeit modest, reduction in endovascular treatment time for patients with stroke. Given the lack of risk and low cost, it is reasonable for stroke centers to consider a highly visible timer in the angio-suite to improve treatment times.

The Pennsylvania Postmarket Multicenter Experience With Flow Redirection Endoluminal Device

BACKGROUND

The flow redirection endoluminal device (FRED) is a novel self-expanding double-layer nitinol braided flow diverter that recently received FDA approval. However, early postmarket studies from the United States are lacking.

OBJECTIVE

To report our short-term multicenter experience.

METHODS

Series of consecutive patients undergoing FRED treatment for intracranial aneurysms were queried from prospectively maintained registries at 4 North-American Centers in Pennsylvania (February 2020-June 2021). The pertinent baseline demographics, aneurysmal characteristics, and procedural outcomes were collected and analyzed, with primary outcome of aneurysmal occlusion and secondary outcome of safety and complications.

RESULTS

Sixty-one patients (median age 58 years, 82% female) underwent 65 FRED treatment procedures for 72 aneurysms. Most (86.1%) of the aneurysms were unruptured; 80.5% were saccular in morphology, and 87.5% were located along the internal carotid artery, with a median size of 7.1 mm (IQR 5.2-11.9 mm). Radiographic follow-up was available in 86.1% of the aneurysms, showing complete occlusion in 74.2% (80% in catheter angiography-only group), and near-complete occlusion in 11.3% of the cases (median 6.3 months), with 2.8% re-treated. Permanent ischemic complications were encountered in 2.8% of the cases, with no procedural mortality. A modified Rankin Scale of 0 to 2 was documented in 98.1% of the patients at the last clinical follow-up (median 6.1 months).

CONCLUSION

The results of the early postmarket experience with the FRED device show reasonable safety and adequate aneurysmal occlusion rates comparable with other flow diverters. However, more extensive multicenter studies with more extended follow-up data are needed to assess the long-term safety and durability of the device.

Abstract WP53: Highly Visible Wall-timer To Reduce Endovascular Treatment Time For Stroke

Background and Purpose: Endovascular therapy for acute ischemic stroke has revolutionized clinical care for stroke patients with large vessel occlusion (LVO), but treatment remains time sensitive. At our stroke center, up to half of the door-to-groin time is accounted for after the patient arrives in the neuro-interventional radiology (NIR) suite. Here we apply the concept of a highly visible timer in the NIR suite to quantify the impact on endovascular treatment time in stroke patients with LVO.

Methods: This was a single-center prospective pseudo-randomized study conducted over a 32-week period (September 14, 2020 through April 25, 2021). Pseudo-randomization was achieved by turning the timer on and off in 2-week intervals. The primary outcome and secondary outcomes were reduction in IR to groin time and 90-day mRS, respectively. We also performed a stratified analysis based on anesthesia status for the procedure along with a multivariate regression to evaluate the effect of the intervention on treatment time while accounting for endotracheal intubation.

Results: During the 32-week study period, 97 mechanical thrombectomies were performed. The timer was ON and OFF for 38 and 59 cases, respectively. The timer resulted in a reduction in IR-to-groin time (27.7 mins vs 32.6 mins; p=0.02). Endotracheal intubation (80% of overall cohort) was associated with a longer NIR-to-groin time (33 mins vs 23 mins; p<0.05). Among patients that underwent intubation, the timer resulted in a reduction in IR-to-intubation time (29.5 mins vs 34.4 mins; p=0.03). After adjusting for intubation status in a multivariate regression, the timer was associated with a 5-minute reduction in IR-to-Groin time (p=0.02). There was no difference in the 90-day mRS between both groups.

Conclusions: A highly visible timer in the NIR suite achieved a meaningful, albeit modest, reduction in endovascular treatment time for stroke patients with LVO. A larger study would be necessary to measure a potential impact on long-term functional outcome, and a multi-center study may be necessary to confirm generalizability. However, based on these results, the lack of risk, and low cost, it is reasonable for stroke centers to consider using a highly visible timer in the NIR suite to improve stroke treatment times.

Artery of Davidoff and Schechter: A Large Angiographic Case Series of Dural AV Fistulas

The artery of Davidoff and Schechter (ADS) is the only meningeal branch of the posterior cerebral artery (PCA), supplying the medial tentorial margin and posterior portions of the falx. Given its small size, it is rarely identified on angiographic studies, unless enlarged in pathologies such as dural arteriovenous fistulas (DAVFs) or vascularized masses. This artery was first described by Wollschlaeger and Wollschlaeger in 1965, and to date, only a few reports have described its significance. The objective of this study is to report our experience with the ADS in dural fistulas from 2 tertiary medical centers and to emphasize the importance of recognizing this artery during angiographic examination of vascular tentorial and posterior fossa lesions. To our knowledge, this report demonstrates the largest angiographic case series published to date, recognizing a total of 7 patients with ADS arising secondary to a posterior fossa or tentorial DAVF and one of the largest reported series of DAVFs supplied by the ADS treated by endovascular and surgical techniques. Our cases validate the importance of prompt identification of the ADS for the diagnosis as well as endovascular treatment of vascular malformations in the posterior fossa and tentorial region.

Carotid artery revascularization using the Walrus balloon guide catheter: safety and feasibility from a US multicenter experience

INTRODUCTION

The Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy.

OBJECTIVE

To report a multi-institutional experience using this BGC for proximal flow control (PFC) in the setting of carotid artery angioplasty/stenting (CAS) in elective (eCAS) and tandem strokes (tCAS).

METHODS

Prospectively maintained databases at 8 North American centers were queried to identify patients with cervical carotid disease undergoing eCAS/tCAS with a Walrus BGC.

RESULTS

110 patients (median age 68, 64.6% male), 80 (72.7%) undergoing eCAS and 30 (27.3%) tCAS procedures, were included (median cervical carotid stenosis 90%; 46 (41.8%) with contralateral stenosis). Using a proximal flow-arrest technique in 95 (87.2%) and flow-reversal in 14 (12.8%) procedures, the Walrus was navigated into the common carotid artery successfully in all cases despite challenging arch anatomy (31, 28.2%), with preferred femoral access (103, 93.6%) and in monitored anesthesia care (90, 81.8%). Angioplasty and distal embolic protection devices (EPDs) were used in 91 (83.7%) and 58 (52.7%) procedures, respectively. tCAS led to a modified Thrombolysis in Cerebral Infarction 2b/3 in all cases. Periprocedural ischemic stroke (up to 30 days postoperatively) rate was 0.9% (n=1) and remote complications occurred in 2 (1.8%) cases. Last follow-up modified Rankin Scale score of 0-2 was seen in 95.3% of eCAS cohort, with no differences in complications in the eCAS subgroup between PFC only versus PFC and distal EPD (median follow-up 4.1 months).

CONCLUSION

Walrus BGC for proximal flow control is safe and effective during eCAS and tCAS. Procedural success was achieved in all cases, with favorable safety and functional outcomes on short-term follow-up.

Combined Endovascular and Microsurgical Management of a Tentorial Arteriovenous Malformation in a Hybrid Neurovascular Operating Room: 2-Dimensional Operative Video

Tentorial margin arteriovenous malformations (AVMs) at the cerebello-mesencephalic fissure are deep lesions, which can be safely resected via a lateral supracerebellar infratentorial approach. This video illustrates the case of a patient who presented with hemorrhage from a tentorial AVM. He was managed in the hybrid neurovascular operating room with Onyx (Medtronic) embolization of a superior cerebellar artery feeder followed by resection of the AVM, which included cerebellar relaxation from lumbar cerebrospinal fluid (CSF) drainage and lateral positioning. Wide cisternal arachnoid dissection at the quadrigeminal cistern allowed for a straight trajectory to the AVM without fixed retraction. Intraoperative transradial angiography confirmed complete AVM exclusion. This video was deemed Institutional Review Board (IRB) exempt by the University of Pennsylvania IRB as it is considered a case report, which does not require IRB approval or patient consent.  The patient consented to the procedure.

Microsurgical Resection and Stabilization of a Giant Spinal Schwannoma: 2-Dimensional Operative Video

We illustrate the microsurgical resection of a giant lumbar spinal schwannoma in a 37-yr-old male who presented with worsening low back pain, weakness, and numbness and tingling in the bilateral legs and feet. Lumbar spine imaging demonstrated a large, heterogeneously enhancing intradural mass with notable bony erosion. Given the thinning of the pedicles, large tumor size, and bony remodeling, instrumentation was performed in addition to decompression, with direct stimulation-triggered electromyography and intraoperative neurophysiological monitoring. This video demonstrates the surgical technique for resection and accompanied reconstruction necessary for the management of these giant intradural lesions. Postoperatively, the patient had no complications, with improvement of neurological symptoms at follow-up. Though improved, the patient had some residual numbness at postoperative follow-up visit. The patient consented to the procedure. This video was deemed Institutional Review Board (IRB) exempt by the University of Pennsylvania IRB, as it is considered a case report, which does not require IRB approval or patient consent.

Radiosurgery as a microsurgical adjunct: outcomes after microsurgical resection of intracranial arteriovenous malformations previously treated with stereotactic radiosurgery

OBJECTIVE

Microsurgical resection of arteriovenous malformations (AVMs) can be aided by staged treatment consisting of stereotactic radiosurgery followed by resection in a delayed fashion. This approach is particularly useful for high Spetzler-Martin (SM) grade lesions because radiosurgery can reduce flow through the AVM, downgrade the SM rating, and induce histopathological changes that additively render the AVM more manageable for resection. The authors present their 28-year experience in managing AVMs with adjunctive radiosurgery followed by resection.

METHODS

The authors retrospectively reviewed records of patients treated for cerebral AVMs at their institution between January 1990 and August 2019. All patients who underwent stereotactic radiosurgery (with or without embolization), followed by resection, were included in the study. Of 1245 patients, 95 met the eligibility criteria. Univariate and multivariate regression analyses were performed to assess relationships between key variables and clinical outcomes.

RESULTS

The majority of lesions treated (53.9%) were high grade (SM grade IV-V), 31.5% were intermediate (SM grade III), and 16.6% were low grade (SM grade I-II). Hemorrhage was the initial presenting sign in half of all patients (49.5%). Complete resection was achieved among 84% of patients, whereas 16% had partial resection, the majority of whom received additional radiosurgery. Modified Rankin Scale (mRS) scores of 0-2 were achieved in 79.8% of patients, and 20.2% had poor (mRS scores 3-6) outcomes. Improved (44.8%) or stable (19%) mRS scores were observed among 63.8% of patients, whereas 36.2% had a decline in mRS scores. This includes 22 patients (23.4%) with AVM hemorrhage and 6 deaths (6.7%) outside the perioperative period but prior to AVM obliteration.

CONCLUSIONS

Stereotactic radiosurgery is a useful adjunct in the presurgical management of cerebral AVMs. Multimodal therapy allowed for high rates of AVM obliteration and acceptable morbidity rates, despite the predominance of high-grade lesions in this series of patients.

Detection of Angiographically Occult Ruptured Basilar Sidewall Perforator Aneurysm by Vessel Wall MR Imaging

Basilar artery perforator aneurysms are rare with a prevalence of less than 1%. These are particularly challenging to detect given their small size and tendency to intermittently thrombose. We describe a case of a ruptured basilar artery sidewall perforator aneurysm that was angiographically occult on computed tomographic angiogram and cerebral catheter angiogram. One day after the initial diagnostic work-up, intracranial vessel wall MR imaging (VWI) was performed which revealed a small outpouching along the right posterolateral basilar arterial wall with a punctate enhancing focus suggestive of a thrombosed basilar perforator artery aneurysm. Thrombus within the small aneurysm sac likely contributed to the poor opacification of the aneurysm sac on conventional lumen-based imaging techniques. Ruptured aneurysms have high morbidity and mortality due to their tendency to rebleed, making their expedient detection and treatment imperative. This case highlights the role VWI can play in detecting small ruptured aneurysms that intermittently thrombose and are otherwise challenging to diagnose with conventional vessel imaging.

Direct Tumoral Puncture Onyx Embolization for a Juvenile Nasopharyngeal Angiofibroma in a Hybrid Neurointerventional Suite

This case video demonstrates a multidisciplinary approach to resection of a juvenile nasopharyngeal angiofibroma highlighting direct intratumoral onyx embolization. The patient is a 14-year-old boy who presented with a 1-month history of worsening epistaxis and nasal congestion. Preoperative magnetic resonance imaging demonstrated a 4.5 x 3 x 3 cm lobulated mass in the right pterygomaxillary space, sphenoid, and the nasopharynx adjacent to the cavernous carotid. Given the high vascularity of the lesion, intratumoral onyx embolization was undertaken, which significantly reduced intraoperative blood loss in this case. The present video demonstrates the technique for safe direct intratumoral onyx embolization and its role in significantly reducing intraoperative blood loss (Video 1). Postoperatively, the patient made an uncomplicated recovery. The patient consented to the procedure.

Application of Advanced Technology During Resection of Posterior Fossa Arteriovenous Malformations: 2 Sister Cases

Various advanced imaging and intraoperative technologies can be used during resection of posterior fossa arteriovenous malformations (AVMs) in a hybrid neurovascular operating room. These technologies include transradial intraoperative angiography with post-processing of angiographic data for navigation (in combination with stereotactic magnetic resonance imaging) (Figure 1). Advanced semiautomated processing allows magnetic resonance imaging, computed tomography angiography, and angiography fusion for enhanced localization of the AVM. Additional useful technologies include processing of angiographic transit time to provide valuable flow data, indocyanine green angiography, fluorescein angiography, and use of a high-definition endoscope. While these technologies are potentially useful in certain circumstances, they may not be necessary in the case of relatively straightforward vascular lesions. Keeping this in mind is of particular importance, as the use of these technologies may require extended time with the patient under anesthesia. These sister cases of cerebellar AVMs illustrate the spectrum of the advanced technologies that are potentially available to surgeons during posterior fossa AVM resection (Video 1).

Microsurgical Treatment of a Complex Cognard V Tentorial Dural Fistula with Superior Cerebellar Artery Supply

This case video demonstrates a microsurgical technique for the clipping and obliteration of a Cognard V tentorial dural fistula (Video 1). The patient was a 49-year-old male who presented with progressive upper and lower extremity weakness over 12 months, with associated cervical spinal cord edema. The patient was initially misdiagnosed with transverse myelitis; however, abnormal flow voids on magnetic resonance imaging led to a cerebral angiogram being performed. The preoperative angiogram demonstrated the Cognard V right tentorial dural arteriovenous fistula with drainage into the dorsal and ventral medullary veins. The fistula resulted in spinal cord symptoms due to spinal cord venous engorgement, with a lack of cranial symptoms. In these cases, microsurgery is the preferred method of treatment due to excellent surgical window to the medial tentorial margin and difficulty in catheterizing the small tortuous superior cerebellar artery meningeal feeder. This is a novel case showing a hybrid operating room technology to safely approach a complex fistula and obtain curative confirmation by transradial intraoperative angiography. In addition, this case is unique in providing a surgical visualization of the meningeal superior cerebellar artery feeder contributing to this fistula, namely the artery of Wollschlaeger & Wollschlaeger. Postoperatively, the patient demonstrated significant improvement in upper and lower extremity strength, indicative of a successful recovery. The patient was discharged to rehabilitation, with continued motor improvement.

Tentorial Dural Arteriovenous Fistulas as a Cause of Thalamic Edema: 2 Cases of an Important Differential Diagnosis to Consider

The differential diagnosis for bilateral thalamic edema is extensive and includes vascular, neoplastic, metabolic, and infectious causes. Of the vascular causes of thalamic edema, arterial and venous infarctions are well-documented, but dural arteriovenous fistulas (dAVFs) are a relatively uncommon and widely underrecognized cause of thalamic edema. Dural AVFs are notoriously difficult to diagnose clinically, especially in the absence of hemorrhage, and cross-sectional imaging findings can be subtle. This can result in a delayed diagnosis, and occasionally, an invasive biopsy for further clarification of a purely vascular disease. In this review, we detail our experience with the imaging diagnosis of dAVF as a cause of thalamic edema and present a short differential of other vascular causes.

Cervical, Intradural Extramedullary Solitary Fibrous Tumor of the Spinal Cord: A Case Report and Review of the Literature

Solitary fibrous tumors (SFTs) are rare, spindle cell neoplasms of the mesenchymal origin. Lesions localized to the spine are exceptionally uncommon, only described in the literature in case reports and small case series. While these lesions are typically benign, there are a few reports in which they recur or present as malignancies. The patient presented in the case herein was a 72-year-old male, who presented with a 1-year history of lower extremity weakness, pain, and numbness and was found to have a cervical, intradural extramedullary tumor. In addition to the case report, the authors perform a thorough review of all previously published cases of spinal SFT.

Abstract TMP118: Clinical Outcomes of Surgical Resection After Stereotactic Radiosurgery Among Patients With Cerebral Arteriovenous Malformations

Introduction: Surgical treatment of arteriovenous malformations (AVMs), particularly higher grade lesions, can be aided by staged treatment consisting of stereotactic radiosurgery (SRS) followed by surgical resection in a delayed fashion. This strategy can be used to downgrade the AVM S-M grade, reduce blood flow through the AVM and often results in histopathological changes making AVMs more amenable to microsurgical resection. We present our 28-year clinical experience in managing AVMs with pre-operative SRS as a surgical adjunct.

Methods: We retrospectively reviewed and analyzed records of all patients treated for cerebral AVMs between February 1991 and July 2019 at our institution. All patients that underwent SRS, with and without embolization, followed by microsurgery were included in the study. Of the 1245 cerebral AVM patients treated at our institution, 62 patients met eligibility criteria. Univariate and multivariate regression analysis was performed where appropriate to examine relationships between key variables and outcomes.

Results: The majority of lesions (50%) were high grade (SM 4-5), 28.6% were intermediate (SM 3), while 21.4% were low grade (SM 1-2). Hemorrhage was the presenting sign among 22.6% of patients. Complete resection was achieved among 64.5%, 79% and 82% of patients after first, second and third surgical stages respectively; 16.1% of patients had partial resection requiring further treatment. Radiographic cure was achieved among 53 patients (85.5%), while 8 (12.9%) patients had residual AVM at last follow up. Six of 8 patients without radiographic cure received post-operative SRS. Thirty-seven patients (63.8%) had improved (26, 44.8%) or stable mRS scores (11, 19%), while 21 (36.2%) had a decline in mRS at final follow up compared to mRS at presentation; this includes 4 (6.9%) deaths due to hemorrhage, outside of the perioperative period, but occurring during follow up prior to AVM obliteration.

Conclusion: SRS is a useful adjunct in the surgical management of cerebral AVMs. Multimodal therapy allowed for high obliteration rates with acceptable morbidity in this series of patients with predominantly high grade AVMs.

Microsurgical excision of a compressive thoracic arachnoid cyst: Technical pearls

The key clinical message of this case is that it is critical to differentiate between arachnoid cysts and spinal cord herniation. This is performed by evaluating the ventral dura to assure that it remains intact.

Microsurgical treatment of tentorial dural fistulas causing thalamic venous hypertension: two illustrative sister cases

This video is a presentation of technical tenets for the microsurgical clipping of a tentorial dural arteriovenous fistula presenting with thalamic venous hypertension. These cases are easily misdiagnosed and often supplied by the tentorial artery of Davidoff and Schecter. The cases shown in the video uniquely illustrate a supracerebellar infratentorial approach to identify and clip an arterialized tentorial vein utilizing intraoperative Doppler and fluorescein, with navigation and an intraoperative cerebral angiogram in a hybrid neuroangiography operative suite. Both patients were found to have thalamic edema on preoperative imaging, which significantly improved postoperatively.The video can be found here: https://youtu.be/HmUO6Ye53QI.

Microsurgical Clipping of Anterior Choroidal Artery Aneurysms: A Systematic Approach to Reducing Ischemic Complications in an Experience with 146 Patients

BACKGROUND

Aneurysms of the anterior choroidal artery (AChA) have been associated with high treatment-associated morbidity due to ischemic complications.

OBJECTIVE

To report a large clinical experience of microsurgically treated AChA aneurysms and describe a systematic approach to reduce ischemic complications.

METHODS

One hundred forty-six patients with AChA aneurysms were retrospectively reviewed from a prospectively maintained database. Clinical characteristics, surgical techniques, clinical outcomes, arterial infarction, and use of intraoperative adjuncts (ie, ultrasonography, indocyanine green videoangiography, and neuromonitoring) were analyzed.

RESULTS

In total, one hundred forty-three aneurysms (97.9%) were clipped. Temporary clipping was utilized in 47 cases (32.2%) with mean occlusion time of 5.6 min. Arterial infarction occurred in 12 patients (8.2%). In clipped aneurysms, 90.5% were completely obliterated, 8.8% had minimal residual (<5% of original), and 0.7% were incompletely occluded (>5% of original). Mortality (2.7%) was limited to patients with high-grade subarachnoid hemorrhage. Indocyanine green videoangiography and neuromonitoring altered operative technique in ∼20% of cases. Multivariate logistic regression identified intraoperative rupture as the sole predictor for arterial infarction.

CONCLUSION

Open microsurgical clipping remains a safe, effective treatment for AChA aneurysms. Microsurgical technique is paramount in preserving AChA patency and reducing ischemic complications. Despite increasing reliance on qualitative measures of AChA blood flow (videoangiography and ultrasonography) and neurophysiological monitoring, these technologies aid us infrequently. However, these adjuncts provide important safety checks for AChA patency. Temporary clipping must be used judiciously to lower the risk of intraoperative rupture while limiting possible ischemia in the AChA territory.

Implementation of a multimodal patient safety improvement program "SafetyLEAP" in intensive care units

Purpose Patient safety remains a top priority in healthcare. Many organizations have developed systems to monitor and prevent harm, and have invested in different approaches to quality improvement. Despite these organizational efforts to better detect adverse events, efficient resolution of safety problems remains a significant challenge. The authors developed and implemented a comprehensive multimodal patient safety improvement program called SafetyLEAP. The term "LEAP" is an acronym that highlights the three facets of the program including: a Leadership and Engagement approach; Audit and feedback; and a Planned improvement intervention. The purpose of this paper is to evaluate the implementation of the SafetyLEAP program in the intensive care units (ICUs) of three large hospitals. Design/methodology/approach A comparative case study approach was used to compare and contrast the adherence to each component of the SafetyLEAP program. The study was conducted using a convenience sample of three ( n=3) ICUs from two provinces. Two reviewers independently evaluated major adherence metrics of the SafetyLEAP program for their completeness. Analysis was performed for each individual case, and across cases. Findings A total of 257 patients were included in the study. Overall, the proportion of the SafetyLEAP tasks completed was 64.47, 100, and 26.32 percent, respectively. ICU nos 1 and 2 were able to identify opportunities for improvement, follow a quality improvement process and demonstrate positive changes in patient safety. The main factors influencing adherence were the engagement of a local champion, competing priorities, and the identification of appropriate resources. Practical implications The SafetyLEAP program allowed for the identification of processes that could result in patient harm in the ICUs. However, the success in improving patient safety was dependent on the engagement of the care teams. Originality/value The authors developed an evidence-based approach to systematically and prospectively detect, improve, and evaluate actions related to patient safety.

Anomalous Origin of the Right Vertebral Artery from the Right Common Carotid Artery

The anomalous origin of the right vertebral artery (VA) from the right common carotid artery (CCA) is a rare vascular anomaly, which is usually clinically asymptomatic and found incidentally during angiographic examinations. This anomaly is invariably associated with an aberrant right subclavian artery (RSCA). Approximately 31 cases have been reported in the literature. We present a case of a right VA originating from the right CCA in a patient with Down syndrome and discuss the imaging findings, embryological etiology of the anomaly, as well as its implications for endovascular/surgical treatment.

Muslin Granuloma Mimicking Parenchymal Hematoma in Patient with Seizures 30 Years After Aneurysm Wrapping

Muslin foreign body granulomas are a known complication of muslin aneurysm wrapping and have been associated with vision loss from optochiasmatic arachnoiditis. Muslin granulomas have also been confused with abscesses due to surrounding inflammatory changes. In this clinical image, we present a unique case of a muslin granuloma mimicking an intraparenchymal hematoma.

High-resolution 3D volumetric contrast-enhanced MR angiography with a blood pool agent (ferumoxytol) for diagnostic evaluation of pediatric brain arteriovenous malformations

OBJECTIVE Patients with brain arteriovenous malformations (AVMs) often require repeat imaging with MRI or MR angiography (MRA), CT angiography (CTA), and digital subtraction angiography (DSA). The ideal imaging modality provides excellent vascular visualization without incurring added risks, such as radiation exposure. The purpose of this study is to evaluate the performance of ferumoxytol-enhanced MRA using a high-resolution 3D volumetric sequence (fe-SPGR) for visualizing and grading pediatric brain AVMs in comparison with CTA and DSA, which is the current imaging gold standard. METHODS In this retrospective cohort study, 21 patients with AVMs evaluated by fe-SPGR, CTA, and DSA between April 2014 and August 2017 were included. Two experienced raters graded AVMs using Spetzler-Martin criteria on all imaging studies. Lesion conspicuity (LC) and diagnostic confidence (DC) were assessed using a 5-point Likert scale, and interrater agreement was determined. The Kruskal-Wallis test was performed to assess the raters' grades and scores of LC and DC, with subsequent post hoc pairwise comparisons to assess for statistically significant differences between pairs of groups at p < 0.05. RESULTS Assigned Spetzler-Martin grades for AVMs on DSA, fe-SPGR, and CTA were not significantly different (p = 0.991). LC and DC scores were higher with fe-SPGR than with CTA (p < 0.05). A significant difference in LC scores was found between CTA and fe-SPGR (p < 0.001) and CTA and DSA (p < 0.001) but not between fe-SPGR and DSA (p = 0.146). A significant difference in DC scores was found among DSA, fe-SPGR, and CTA (p < 0.001) and between all pairs of the groups (p < 0.05). Interrater agreement was good to very good for all image groups (κ = 0.77-1.0, p < 0.001). CONCLUSIONS Fe-SPGR performed robustly in the diagnostic evaluation of brain AVMs, with improved visual depiction of AVMs compared with CTA and comparable Spetzler-Martin grading relative to CTA and DSA.

Duplication of the vertebral artery: A series of four cases

INTRODUCTION

Duplication of the vertebral artery (VA) is a rare vascular variant, with less than 50 reported cases in the literature.

CASE SERIES

We present four cases of VA duplication and discuss the imaging findings, which highlight the rarely seen VA duplication.

DISCUSSION

VA duplication is generally considered to be an incidental finding. The VA is formed from the fusion of the longitudinal anastomoses that link the cervical intersegmental arteries, during the 32-40-day stage. The duplication of the VA is a clinically relevant finding for planning of head and neck surgery and neuro-interventional procedures.

Dural Arteriovenous Fistula Associated With a Vestibular Tumor: An Unusual Case and Review of the Literature

Intracranial dural arteriovenous fistulae (DAVF) are rare vascular malformations. They are generally considered to be acquired lesions, often attributed to dural sinus thrombosis and intracranial venous hypertension. The authors encountered a case of DAVF associated with an octreotide-positive vestibular schwannoma. A 46-year-old female had symptoms of right ear congestion accompanied by pulsatile tinnitus and mild hearing loss. Magnetic resonance imaging (MRI) identified a lobulated mass centered at the cerebellopontine angle. Preoperatively, on cerebral angiography, there was an incidental discovery of a DAVF in the right posterior fossa. The decision was made to proceed with resection of the tumor in a staged fashion. Her latest follow-up MRI showed no evidence of recurrent tumor. This is the second reported case of DAVF associated with an intracranial schwannoma. Findings are discussed along with a thorough review of the literature. This case, combined with the data from the literature review, led us to believe that tumor-related angiogenesis might contribute to DAVF formation.

Complications Following Transradial Cerebral Angiography : An Ultrasound Follow-Up Study

OBJECTIVE

The feasibility and usefulness of transradial catheterization for coronary and neuro-intervention are well known. However, the anatomical change in the catheterized radial artery (RA) is not well understood. Herein, we present the results of ultrasonographic observation of the RA after routine transradial cerebral angiography (TRCA).

METHODS

Patients who underwent routine TRCA with pre- and post-procedure Doppler ultrasonography (DUS) of the catheterized RA were enrolled. We then recorded and retrospectively reviewed the diameter and any complicated features of the RA observed on DUS, and the factors associated with the diameter and complications were analyzed.

RESULTS

A total of 223 TRCAs across 181 patients were enrolled in the current study. The mean RA diameter was 2.48 mm and was positively correlated with male gender (p<0.001) and hypertension (p<0.002). The median change in diameter after TRCA was less than 0.1 mm (range, -1.3 to 1.2 mm) and 90% of changes were between -0.8 and +0.7 mm. Across 228 procedures, there were 12 cases (5.3%) of intimal hyperplasia and 22 cases (9.6%) of asymptomatic local vascular complications found on DUS. Patients with abnormal findings on the first procedure had a smaller pre-procedural RA diameter than that of patients without findings (2.26 vs. 2.53 mm, p=0.0028). There was no significant difference in the incidence of abnormal findings for the first versus subsequent procedures (p=0.68).

CONCLUSION

DUS identified the pre- and post-procedural diameter and local complications of RA. Routine TRCA seems to be acceptable with regard to identifying local complications and changes in RA diameter.

Contralateral transcallosal resection of a ventricular body arteriovenous malformation: 3D operative video

A 46-year-old male presented with an incidentally discovered left ventricular body arteriovenous malformation (AVM). It measured 2 cm in diameter and had drainage via an atrial vein into the internal cerebral vein (Spetzler-Martin Grade III, Supplementary Grade 4). Preoperative embolization of the posterior medial choroidal artery reduced nidus size by 50%. Subsequently, he underwent a right-sided craniotomy for a contralateral transcallosal approach to resect the AVM. This case demonstrates strategic circumferential disconnection of feeding arteries (FAs) to the nidus, the use of aneurysm clips to control large FAs, and the use of dynamic retraction and importance of a generous callosotomy. Postoperatively, he was neurologically intact, and angiogram confirmed complete resection. The video can be found here: https://youtu.be/j0778LfS3MI .

Macrovascular Decompression of the Brainstem and Cranial Nerves: Evolution of an Anteromedial Vertebrobasilar Artery Transposition Technique

BACKGROUND: Tortuous and dolichoectatic vertebrobasilar arteries can impinge on the brainstem and cranial nerves to cause compression syndromes. Transposition techniques are often required to decompress the brainstem with dolichoectatic pathology. We describe our evolution of an anteromedial transposition technique and its efficacy in decompressing the brainstem and relieving symptoms.

OBJECTIVE: To present the anteromedial vertebrobasilar artery transposition technique for macrovascular decompression of the brainstem and cranial nerves.

METHODS: All patients who underwent vertebrobasilar artery transposition were identified from the prospectively maintained database of the Vascular Neurosurgery service, and their medical records were reviewed retrospectively. The extent of arterial displacement was measured pre- and postoperatively on imaging.

RESULTS: Vertebrobasilar arterial transposition and macrovascular decompression was performed in 12 patients. Evolution in technique was characterized by gradual preference for the far-lateral approach, use of a sling technique with muslin wrap, and an anteromedial direction of pull on the vertebrobasilar artery with clip-assisted tethering to the clival dura. With this technique, mean lateral displacement decreased from 6.6 mm in the first half of the series to 3.8 mm in the last half of the series, and mean anterior displacement increased from 0.8 to 2.5 mm, with corresponding increases in satisfaction and relief of symptoms.

CONCLUSION: Compressive dolichoectatic pathology directed laterally into cranial nerves and posteriorly into the brainstem can be corrected with anteromedial transposition towards the clivus. Our technique accomplishes this anteromedial transposition from an inferolateral surgical approach through the vagoaccessory triangle, with sling fixation to clival dura using aneurysm clips.

Operative volume and outcomes of cerebrovascular neurosurgery in children

OBJECTIVE The impact of procedural volume on the outcomes of cerebrovascular surgery in children has not been determined. In this study, the authors investigated the association of operative volume on the outcomes of cerebrovascular neurosurgery in pediatric patients. METHODS The authors performed a cohort study of all pediatric patients who underwent a cerebrovascular procedure between 2003 and 2012 and were registered in the Kids' Inpatient Database (KID). To control for confounding, the authors used multivariable regression models, propensity-score conditioning, and mixed-effects analysis to account for clustering at the hospital level. RESULTS During the study period, 1875 pediatric patients in the KID underwent cerebrovascular neurosurgery and met the inclusion criteria for the study; 204 patients (10.9%) underwent aneurysm clipping, 446 (23.8%) underwent coil insertion for an aneurysm, 827 (44.1%) underwent craniotomy for arteriovenous malformation resection, and 398 (21.2%) underwent bypass surgery for moyamoya disease. Mixed-effects multivariable regression analysis revealed that higher procedural volume was associated with fewer inpatient deaths (OR 0.58; 95% CI 0.40-0.85), a lower rate of discharges to a facility (OR 0.87; 95% CI 0.82-0.92), and shorter length of stay (adjusted difference -0.22; 95% CI -0.32 to -0.12). The results in propensity-adjusted multivariable models were robust. CONCLUSIONS In a national all-payer cohort of pediatric patients who underwent a cerebrovascular procedure, the authors found that higher procedural volume was associated with fewer deaths, a lower rate of discharges to a facility, and decreased lengths of stay. Regionalization initiatives should include directing children with such rare pathologies to a center of excellence.

Seven-Tesla MRI and neuroimaging biomarkers for Alzheimer's disease

The goal of this paper was to review the effectiveness of using 7-T MRI to study neuroimaging biomarkers for Alzheimer's disease (AD). The authors reviewed the literature for articles published to date on the use of 7-T MRI to study AD. Thus far, there are 3 neuroimaging biomarkers for AD that have been studied using 7-T MRI in AD tissue: 1) neuroanatomical atrophy; 2) molecular characterization of hypointensities; and 3) microinfarcts. Seven-Tesla MRI has had mixed results when used to study the 3 aforementioned neuroimaging biomarkers for AD. First, in the detection of neuroanatomical atrophy, 7-T MRI has exciting potential. Historically, noninvasive imaging of neuroanatomical atrophy during AD has been limited by suboptimal resolution. However, now there is compelling evidence that the high resolution of 7-T MRI may help overcome this hurdle. Second, in detecting the characterization of hypointensities, 7-T MRI has had varied success. PET scans will most likely continue to lead in the noninvasive imaging of amyloid plaques; however, there is emerging evidence that 7-T MRI can accurately detect iron deposits within activated microglia, which may help shed light on the role of the immune system in AD pathogenesis. Finally, in the detection of microinfarcts, 7-T MRI may also play a promising role, which may help further elucidate the relationship between cerebrovascular health and AD progression.

Indirect and direct revascularization of ACTA2 cerebral arteriopathy: feasibility of the superficial temporal artery to anterior cerebral artery bypass with posterior auricular artery interposition graft: case report

Mutations in the smooth muscle-specific isoform of alpha actin (ACTA2) cause smooth muscle dysfunction in arteries. This rare loss-of-function mutation may cause a diffuse occlusive cerebral arteriopathy, resulting in stroke. While ACTA2 arteriopathy is often described as moyamoya-like, it has a distinct phenotype characterized by dilation of the proximal internal carotid artery (ICA) and occlusion of the terminal ICA and proximal middle cerebral artery. Intracranial arteries have an abnormally straight course, often with small aneurysms. There is limited experience with revascularization procedures for ACTA2 arteriopathy, and the safety and efficacy of these procedures are unknown. In this paper the authors present a symptomatic 6-year-old patient with ACTA2 cerebral arteriopathy who underwent both indirect revascularization and direct cerebrovascular bypass. Postoperatively, the patient suffered an ischemic infarct in a neighboring vascular territory. While direct cerebrovascular bypass is technically feasible, patients with ACTA2 arteriopathy may be at increased risk for perioperative stroke compared with patients with moyamoya disease.

Increased risk for complications following diagnostic cerebral angiography in older patients: Trends from the Nationwide Inpatient Sample (1999-2009)

The full utility of diagnostic cerebral angiography, an invasive cerebrovascular imaging technique, is currently debated. Our goal was to determine trends in diagnostic cerebral angiography utilization and associated complications from 1999 through 2009. The National Inpatient Sample (NIS) was used to identify patients who received primary cerebral angiography from 1999-2009 in the United States. We observed trends in discharge volume, total mean charge, and post-procedural complications for this population. Data was based on sample projections and analyzed using univariate and multivariate regression. There were a total of 424,105 discharges indicating primary cerebral angiography nationwide from 1999-2009. The majority of these cases (65%) were in patients older than 55years. Embolic stroke was the most frequent complication, particularly in the oldest age bracket, occurring in 16,304 patients. The risk for complications increased with age (p<0.0001) and with other underlying health conditions. Pulmonary, deep vein thrombosis, and renal associated comorbidities resulted in the greatest risk for developing post-procedural complications. Throughout the study period case volume for cerebral angiography remained constant while total charge per patient increased from $17,365 in 1999 to $45,339 in 2009 (p<0.001). While the overall complication rate for this invasive procedure is relatively low, the potential risk for embolic stroke in older patients is significant. It is worth considering less invasive diagnostic techniques for an older and at risk patient population.

Brainstem cavernous malformations: Natural history versus surgical management

While brainstem cavernous malformations were once considered inoperable, improvements in patient selection, surgical exposures, intraoperative MRI-guidance, MR tractography, and neurophysiologic monitoring have resulted in good outcomes in the majority of operated patients. In a consecutive series of 104 patients with brainstem cavernous malformations, only 14% of patients experienced cranial nerve or motor dysfunction that was worse at late follow-up, relative to their preoperative condition. Outcomes were predicted by several factors, including larger lesion size, lesions that crossed the midline, the presence of a developmental venous anomaly, older age, and greater time interval from lesion hemorrhage to surgery. The 14% of patients who experienced a persistent neurological deficit as a result of surgery, while substantial from any perspective, compares favorably with the risks of observation based on a recent meta-analysis. Curative resection is a safe and effective treatment for brainstem cavernous malformations that will prevent re-hemorrhage in symptomatic patients.

Predictive modeling and in vivo assessment of cerebral blood flow in the management of complex cerebral aneurysms

Cerebral aneurysms are weakened blood vessel dilatations that can result in spontaneous, devastating hemorrhage events. Aneurysm treatment aims to reduce hemorrhage events, and strategies for complex aneurysms often require surgical bypass or endovascular stenting for blood flow diversion. Interventions that divert blood flow from their normal circulation patterns have the potential to result in unintentional ischemia. Recent developments in computational modeling and in vivo assessment of hemodynamics for cerebral aneurysm treatment have entered into clinical practice. Herein, we review how these techniques are currently utilized to improve risk stratification and treatment planning.