Adverse Events Associated with Intra-Arterial Administration of Gadolinium-Based Contrast Agents: A Systematic Review and Meta-Analysis.

PURPOSE: To determine the risk of immediate hypersensitivity reactions (HRs), contrast-associated acute kidney injury (CA-AKI), nephrogenic systemic fibrosis (NSF), and gadolinium retention associated with use of intra-arterial gadolinium-based contrast agents (GBCAs). MATERIALS AND METHODS: MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched from 1988 (GBCAs approved for clinical use) to March 2021 for studies reporting adverse events associated with intra-arterial administration of GBCAs. The number of adverse events and GBCA administrations were used to calculate incidence in individual studies, and results across studies were pooled using random-effects meta-analysis. RESULTS: There were 72 studies (patients = 1,221) that reported on HR, 59 studies (patients = 1,142) that reported on CA-AKI, and 6 studies (patients = 291) that reported on NSF. No studies reported gadolinium retention as an outcome. Based on 5 events and 1,451 GBCA administrations, the incidence of HR per 100 administrations was 0.95 (95% CI, 0.52-1.51). Based on 90 events and 1,318 GBCA administrations, the incidence of CA-AKI per 100 administrations was 5.94 (95% CI, 3.92-8.34). Based on 7 events and 361 GBCA administrations, the incidence of NSF per 100 Group I GBCA administrations was 4.72 (95% CI, 0.35-13.70). There were no unconfounded NSF events after Group II GBCA administration. CONCLUSIONS: HRs to intra-arterial administration of GBCAs are rare, with no serious reactions. Limited data demonstrate a higher-than-expected rate of CA-AKI; however, multiple confounding factors were noted. Thus, any causative link of CA-AKI to GBCA remains controversial. Also, severe physiologic reactions (including life-threatening arrhythmias) during coronary angiography have been reported.

Distal to proximal snaring of a fractured microcatheter during dural AVF embolization.

Detachable-tip microcatheters are frequently used for endovascular embolization of arteriovenous shunts. Occasionally, the detachable tip can break during navigation resulting in the loss of the microcatheter tip in a vessel, which can lead to thrombo-embolic complications and also limit further navigation into the vessel to complete treatment. We present a case of dural AV-fistula embolization that was complicated by the accidental detachment and loss of the tip of a microcatheter during navigation to injection site. The proximal tip of the broken catheter was not visible and therefore we were unable to capture its proximal part with a Snare. Ultimately, we navigated a microcatheter distal to the broken segment and successfully snared the microcatheter fragment retrogradely. (Video 1).

High sensitivity and specificity of 4D-CTA in the detection of cranial arteriovenous shunts.

PURPOSE: In a prospective cohort study, we evaluated the diagnostic accuracy of time-resolved CT angiography (4D-CTA) compared to digital subtraction angiography (DSA) for detecting cranial arteriovenous shunts. MATERIAL AND METHODS: Patients were enrolled if a DSA had been ordered querying either a dural arteriovenous fistula (dAVF) or a cerebral arteriovenous malformation (bAVM). After enrolment, both a DSA and a 4D-CTA were performed. Both studies were evaluated using a standardized form. If a dAVF or bAVM was found, its classification, angioarchitectural details, and treatment options were recorded. RESULTS: Ninety-eight patients were enrolled and 76 full datasets were acquired. DSA demonstrated a shunting lesion in 28 out of 76 cases (prevalence 37%). 4D-CTA demonstrated all but two of these lesions (sensitivity of 93%) and produced one false positive (specificity of 98%). These numbers yielded a positive predictive value (PPV) of 96% and a negative predictive value (NPV) of 96%. Significant doubt regarding the 4D-CTA diagnosis was reported in 6.6% of all cases and both false-negative 4D-CTA results were characterized by such doubt. CONCLUSIONS: 4D-CTA has very high sensitivity and specificity for the detection of intracranial arteriovenous shunts. Based on these results, 4D-CTA may replace DSA imaging as a first modality in the diagnostic workup in a large number of patients suspected of a cranial dAVF or bAVM, especially if there is no doubt regarding the 4D-CTA diagnosis. KEY POINTS: • 4D-CTA was shown to have a high diagnostic accuracy and is an appropriate, less invasive replacement for DSA as a diagnostic tool for cranial arteriovenous shunts in the majority of suspected cases. • Doubt regarding the 4D-CTA result should prompt additional DSA imaging, as it is associated with false negatives. • False-positive 4D-CTA results are rare, but do exist.

Survival analysis of risk factors for major recurrence of intracranial aneurysms after coiling.

BACKGROUND: Recurrence after intracranial aneurysm coiling is a highly prevalent outcome, yet to be understood. We investigated clinical, radiological and procedural factors associated with major recurrence of coiled intracranial aneurysms. METHODS: We retrospectively analyzed prospectively collected coiling data (2003-12). We recorded characteristics of aneurysms, patients and interventional techniques, pre-discharge and angiographic follow-up occlusion. The Raymond-Roy classification was used; major recurrence was a change from class I or II to class III, increase in class III remnant, and any recurrence requiring any type of retreatment. Identification of risk factors associated with major recurrence used univariate Cox Proportional Hazards Model followed by multivariate regression analysis of covariates with P<0.1. RESULTS: A total of 467 aneurysms were treated in 435 patients: 283(65%) harboring acutely ruptured aneurysms, 44(10.1%) patients died before discharge and 33(7.6%) were lost to follow-up. A total of 1367 angiographic follow-up studies (range: 1-108 months, Median [interquartile ranges (IQR)]: 37[14-62]) was performed in 384(82.2%) aneurysms. The major recurrence rate was 98(21%) after 6(3.5-22.5) months. Multivariate analysis (358 patients with 384 aneurysms) revealed the risk factors for major recurrence: age>65 y (hazard ratio (HR): 1.61; P=0.04), male sex (HR: 2.13; P<0.01), hypercholesterolemia (HR: 1.65; P=0.03), neck size ≥4 mm (HR: 1.79; P=0.01), dome size ≥7 mm (HR: 2.44; P<0.01), non-stent-assisted coiling (HR: 2.87; P=0.01), and baseline class III (HR: 2.18; P<0.01). CONCLUSION: Approximately one fifth of the intracranial aneurysms resulted in major recurrence. Modifiable factors for major recurrence were choice of stent-assisted technique and confirmation of adequate baseline occlusion (Class I/II) in the first coiling procedure.

Factors Determining Periprocedural and Long-term Complications of High Risk Carotid Artery Stenting.

BACKGROUND AND PURPOSE: Carotid artery stenting (CAS) has been, historically, an alternative to open endarterectomy (CEA) for stroke prevention in high risk patients with carotid atherosclerosis. We sought to determine the rates of periprocedural and long-term stroke or death and the risk factors for complications after CAS in our high risk patient population. METHODS: Clinical and treatment variables of consecutive CAS procedures performed between 2002 and 2011 were analyzed. Using univariate and multivariate logistic regression analyses we examined how patient characteristics influenced outcomes and changes in modified Rankin Score (mRS). RESULTS: In 152 patients, the composite total of periprocedural death, stroke, transient ischemic attack (TIA) and myocardial infarction (MI) rate was 3.95% (6/152). Chronic kidney disease (CKD) was strongly associated with periprocedural complications (p<0.001). Coronary artery disease/peripheral vascular disease (CAD/PVD) (p=0.03), dyslipidemia (p=0.02), CKD (p=0.01), and contralateral internal carotid artery stenosis (p=0.02) were non-modifiable risk factors for mRS increase. There were 25 deaths, 8 strokes, 11 TIAs, and 1 MI (mean follow-up 38.4 months, range 0-116 months). The presence of CAD/PVD (p=0.009) and dyslipidemia (p=0.002) were significantly associated with long-term complications. CONCLUSION: CAS was performed with low periprocedural complications in high-risk patients. Our rates compare very favorably to large-scale trials that have ideal patients. This data encourages the consideration of CAS in patients considered high risk for CEA and provides possible patient characteristics (CKD) to help with periprocedural risk stratification.

Imaging diagnosis and the role of endovascular embolization treatment for vascular intraspinal tumors.

Intraspinal tumors comprise a large spectrum of neoplasms, including hemangioblastomas, paragangliomas, and meningiomas. These tumors have several common characteristic imaging features, such as highly vascular mass appearance in angiography, hypointense rim and serpentine flow voids in MRI, and intense enhancement after intravenous contrast administration. Due to their rich vascularity, these tumors represent a special challenge for surgical treatment. More recently, the surgical treatment of intraspinal vascular tumors has benefited from the combination of endovascular techniques used to better delineate these lesions and to promote preoperative reduction of volume and tissue blood flow. Endovascular embolization has been proven to be a safe procedure that facilitates the resection of these tumors; hence, it has been proposed as part of the standard of care in their management.

Computed tomographic angiography and cerebral blood volume can predict final infarct volume and outcome after recanalization.

BACKGROUND AND PURPOSE: Recanalization rates are higher in acute anterior stroke treated with stent-retrievers when compared with older techniques. However, some still have sizeable infarcts and poor outcome. This may be related to underestimation of core infarct on nonenhanced computed tomography (NECT). CT angiography (CTA) source images (CTASI) and CT perfusion may be more informative. We hypothesize that core infarct estimation with NECT, CTA, and CT perfusion predicts infarct at 24 hours and outcome after fast recanalization. METHODS: Consecutive good recanalization patients with proximal anterior circulation stroke were evaluated. We assessed Alberta Stroke Program Early CT Score (ASPECTs) on NECT for subtle early infarct, hypodensity, loss of gray-white (CTASI), and low cerebral blood volume (CBV; CT perfusion). Sensitivity and specificity for predicting infarct by region were calculated. RESULTS: Of 46 patients, 36 (78%) had successful thrombectomy. Median ASPECTS was 10 for NECT early infarct and frank hypodensity; for CBV, CTASI-ASPECTS was 8. CTASI had the highest sensitivity of 71% and specificity of 82% for 24 hours NECT infarct. There was moderate correlation and concordance between CBV/24-hour NECT (Rp=0.51; Rc=0.50) and CTASI/24-hour NECT (Rp=0.54 and Rc=0.53). Thirty-four patients (74%) had good outcomes. Median ASPECTS was higher on CTASI (8 versus 5; P=0.04) and CBV (9 versus 5; P=0.03) for patients with good versus bad outcome. There were better outcomes with increasing CTASI-ASPECTS (P=0.004) and CBV-ASPECTS (P=0.02). CONCLUSIONS: CTASI and CBV were better at predicting 24-hour infarct and outcome than NECT. Appropriate advanced imaged guided selection may improve outcomes in large-vessel stroke treated with the newest techniques.

Central nervous system venulitis presenting as migraine.

OBJECTIVE: To describe a case of pediatric central nervous system (CNS) venulitis. BACKGROUND: Primary angiitis of the CNS is a rare but increasingly well-recognized cause of morbidity in children. It primarily involves the arteries and arterioles of the CNS, with only 1 published case of a pediatric patient found to have isolated CNS venulitis on brain biopsy. CASE REPORT: A 17-year-old female with a 4-year history of migraines presented with increasingly frequent migraines and right-sided hemiplegia. Infectious, hematologic, and rheumatologic work-ups were negative. Brain magnetic resonance imaging showed multiple rim-enhancing lesions consistent with calcifications affecting the deep left white matter. On brain biopsy, there was evidence of an inflammatory process involving small veins and venules. The patient displayed clinical improvement with a course of high-dose steroids and 6 monthly cyclophosphamide infusions followed by maintenance therapy with mycophenolate mofetil. DISCUSSION: We describe a case of pediatric CNS venulitis presenting with migraine.

Navigation of Stents across Communicating Arteries for Aneurysm Embolization.

INTRODUCTION: Endovascular coiling of aneurysms crossing the Circle of Willis has been described in small case series. The technical challenges in manipulating a stent across the Circle of Willis lie in negotiating difficult angles and small arteries. We present our experience with treating aneurysms by stent assistance in which the Circle of Willis was crossed to facilitate optimal stent deployment. MATERIALS AND METHODS: We retrospectively reviewed the cases in our institution from January 2009 to June 2012 in which the Circle of Willis was traversed to facilitate optimal stent deployment. We measured the diameter of the communicating arteries traversed, caliber of the target arteries in which the stent was deployed and the most acute angle negotiated ("critical angle"). We compare our results with other published series in the literature. RESULTS: Eight patients fulfilled the criteria: 5 males (45-66 years). There were three anterior and five posterior circulation aneurysms. Four of the aneurysms were ruptured. The PCOM was traversed in five cases, the ACOM in three cases. The mean diameter of the communicating artery was 1.17 mm. The mean diameter of target arteries was 1.27 mm. The "critical angle" was 72-147 degrees. In all patients, there was satisfactory obliteration of the aneurysm. There were two cases of minor SAH post procedure. CONCLUSION: Utilizing the Circle of Willis for optimal stent placement in aneurysm remodeling is technically feasible but challenging. This technique can be performed successfully in patients with acute SAH. The procedural risk must be balanced against potential complications such as SAH.

Acute stroke patients treated with stent retrievers in carotid "T" occlusions have improved recanalization and outcome.

BACKGROUND: Recanalization rates and patient outcomes in acute occlusion of the carotid terminus have previously been poor. The use of stent-retrievers has resulted in better recanalization and patient outcomes. We sought to compare outcomes in patients treated with stent-retrievers to outcomes in older techniques. METHODS: We retrospectively compared a stent-retriever cohort to a historical cohort. We evaluated recanalization rates and good outcomes (defined as mRS < 2 at 30 days or 10 point drop in NIHSS). RESULTS: There were twenty patients treated with stent-retrievers versus nine without. The recanalization rate in patients treated with stent retrievers was significantly higher than that of other modalities (90% vs 33%, p=0.004). Good outcomes were significantly higher in the stent retriever cohort (70% vs 22%, p=0.041). CONCLUSION: The use of stent-retrievers in patients with carotid "T" occlusions shows promise in comparison to older techniques. A randomized trial comparing stent-retriever therapy to IV thrombolysis is warranted to determine the efficacy of this new generation of devices.

Perimesencephalic subarachnoid hemorrhage as a rare delayed complication of radiation therapy in a patient with parotid basaloid squamous cell carcinoma.

In this case report, we address a rare entity of parotid cancer: basaloid squamous cell carcinoma, which was surgically unresectable and had thus far only been treated with radiation therapy. Following twenty years of continuous remission, our patient presented with an acute perimesencephalic subarachnoid hemorrhage. The cause of the acute perimesencephalic subarachnoid hemorrhage was a delayed complication of radiation therapy.

Clinical and radiographic response of a paravertebral hemangioma to radiotherapy.

Hemangiomas can arise anywhere in the body. While vertebral hemangiomas are common, atypical hemangiomas with paraspinal and epidural extension are rare. We present a case of a patient who presented with persistent cough and anorexia from a paravertebral hemangioma that invaded the adjacent vertebrae and neural foramen causing moderate spinal canal stenosis. She was treated with stereotactic body radiotherapy to prevent the development of symptomatic spinal cord compression. The hemangioma underwent significant shrinkage and her cough resolved. This case demonstrates impressive and sustained clinical and radiographic response of a paraspinal hemangioma to stereotactic body radiotherapy.

Embolization of a pseudoaneurysm of the innominate artery with a Woven EndoBridge (WEB) device.

The Woven EndoBridge (WEB) is an intra-aneurysmal flow disruptor designed for the treatment of broad-based arterial aneurysms with a high safety and effectiveness profile.1, 2 It does not require concomitant antiplatelet therapy compared to other devices such as flow diverters or intracranial stents. Innominate artery pseudoaneurysms are a rare consequence of blunt traumatic injury, infection, or atherosclerotic disease.3, 4 We describe the case of an innominate artery pseudoaneurysm successfully treated with a WEB SL device instead of stenting, therefore alleviating the need for dual antiplatelet therapy. The treatment was successful and uneventful and postprocedural computed tomography angiography confirmed the complete occlusion of the pseudoaneurysm.

A Pilot Clinical and Technical Validation of an Immersive Virtual Reality Platform for 3D Anatomical Modeling and Contouring in Support of Surgical and Radiation Oncology Treatment Planning.

The aim of this study was to validate a novel medical virtual reality (VR) platform used for medical image segmentation and contouring in radiation oncology and 3D anatomical modeling and simulation for planning medical interventions, including surgery. The first step of the validation was to verify quantitatively and qualitatively that the VR platform can produce substantially equivalent 3D anatomical models, image contours, and measurements to those generated with existing commercial platforms. To achieve this, a total of eight image sets and 18 structures were segmented using both VR and reference commercial platforms. The image sets were chosen to cover a broad range of scanner manufacturers, modalities, and voxel dimensions. The second step consisted of evaluating whether the VR platform could provide efficiency improvements for target delineation in radiation oncology planning. To assess this, the image sets for five pediatric patients with resected standard-risk medulloblastoma were used to contour target volumes in support of treatment planning of craniospinal irradiation, requiring complete inclusion of the entire cerebral-spinal volume. Structures generated in the VR and the commercial platforms were found to have a high degree of similarity, with dice similarity coefficient ranging from 0.963 to 0.985 for high-resolution images and 0.920 to 0.990 for lower resolution images. Volume, cross-sectional area, and length measurements were also found to be in agreement with reference values derived from a commercial system, with length measurements having a maximum difference of 0.22 mm, angle measurements having a maximum difference of 0.04°, and cross-sectional area measurements having a maximum difference of 0.16 mm2. The VR platform was also found to yield significant efficiency improvements, reducing the time required to delineate complex cranial and spinal target volumes by an average of 50% or 29 min.

Development of a Digital Platform: A Perspective to Advance Space Telepharmacy.

Goal: Lessons learned from decades of human spaceflight have helped advance the delivery of healthcare in rural and remote areas of the globe. Inclusion of the public in spaceflights is not yet accompanied by technology capable of monitoring their physical and mental health, managing clinical conditions, and rapidly identifying medical emergencies. Telepharmacy is a practice prioritizing pharmacotherapeutic guidance and monitoring to help improve patient quality of life, and can potentially expand the field of space medicine. We seek to advance pharmaceutical care through telepharmacy by developing a digital platform. Objective: This study focuses on the development of a digital platform for teleassistance and pharmaceutical teleconsulting services that builds on lessons learned in delivering space medicine. Methods: The platform contains evidence-based information on various drugs grouped by medical specialty, and also records and saves patient appointments. It has specific service protocols for service standardization, including artificial intelligence, to allow agility in services and escalation. All data is protected by privacy and professional ethics guidelines. Results: The telepharmacy platform is ready and currently undergoing testing for ground applications through validation studies in hospitals or medical clinics. Conclusions: Although developed for use on Earth, this telepharmacy platform provides a good example of how terrestrial healthcare knowledge and technology can be transferred to space missions.

Stent retriever for Tandem Acute Revascularization Technique (START): a novel technique for the endovascular management of tandem occlusions.

Tandem occlusions, characterized by the simultaneous presence of an intracranial large vessel occlusion and extracranial carotid artery stenosis or occlusion,1 pose a unique endovascular challenge.2 3 Typically, the extracranial occlusion is a result of atherosclerotic plaque; however, dissections are also a possible cause. It is currently uncertain whether an intracranial first approach or an extracranial first approach should be employed.4 5 A new technique has been developed which allows for the simultaneous treatment of both the intracranial and the extracranial lesion.6 We describe a variation of this technique: the stent retriever for tandem acute revascularization technique (START), which consists of simultaneously treating the intracranial lesion with stent retriever and contact aspiration, and the extracranial lesion with balloon angioplasty. We present a technical video explaining all the steps of START.(video 1)neurintsurg;jnis-2023-021011v1/V1F1V1Video 1Description and example of the START.

Use of a Woven Endobridge device (WEB) for the treatment of an aneurysmal diverticulum of the transverse sinus causing pulsatile tinnitus.

Pulsatile tinnitus is a symptom with a potentially significant impact on the quality of life of patients.1 In some cases the pulsatile tinnitus is secondary to an arterial, arteriovenous, or a venous condition that can be treated endovascularly.2-5 One of the newly recognized entities that can cause pulsatile tinnitus is the presence of an ipsilateral aneurysmal diverticulum of the transverse sinus. The Woven EndoBridge (WEB) is an intra-aneurysmal flow disruptor for the treatment of broad-based arterial aneurysms with a high safety and effectiveness profile.3 The initial version of the WEB with a dual-layer structure evolved into a single-layer structure in two different versions (WEB SL, a barrel shape, and WEB SLS, a spherical shape).4 The WEB system does not require concomitant antiplatelet therapy, unlike other intraluminal devices such as flow diverters or intracranial stents. We describe a case of pulsatile tinnitus secondary to an aneurysmal diverticulum of the transverse sinus successfully treated with a WEB SL device instead of stent-assisted coiling, therefore alleviating the need for antiplatelets (video 1). The patient had an immediate clinical response with complete and persisting disappearance of her pulsatile tinnitus.neurintsurg;jnis-2023-020981v1/V1F1V1Video 1.

Factors affecting long-term restenosis after carotid stenting for carotid atherosclerotic disease.

INTRODUCTION: The most significant factors leading to restenosis are yet to be described in the literature. The purpose of our study was to identify the incidence of restenosis in our patients with carotid artery stenting (CAS) for carotid atherosclerotic disease and to identify risk factors that are significantly responsible or related to the restenosis. METHODS: In this retrospective analysis of patients who underwent CAS for atherosclerotic disease between years 2002 and 2006, we studied various demographic, clinical, and medical factors, plaque characteristics, and technical aspects of CAS. All patients were followed up with carotid Doppler ultrasound at baseline (after 2 to 4 weeks of CAS) and then with Doppler ultrasound and clinically for various intervals of time. The restenosis was classified based on carotid Doppler ultrasound results. Clinically, restenosis was classified as symptomatic or asymptomatic. Pearson correlation coefficient was used to assess the statistical correlation of the different factors with the incidence of restenosis. RESULTS: We had a total of 105 patients, with a total of 204.6 patient-year follow-up (mean, 1.95 years; range, 0-7.3 years). The overall incidence of restenosis was 26.7 % (n = 28): mild, 7.6 % (n = 8); moderate, 10.5 % (asymptomatic, 11; symptomatic, 0); and severe, 8.6 % (asymptomatic, 5; symptomatic, 4). Overall, 14.3 % (n = 4) patients with restenosis were symptomatic and 7.1 % (n = 2) underwent retreatment. Post-stenting residual stenosis greater than either 30 % (p = 0.016) or 50 % (p = 0.05) were significant for long-term restenosis. Plaques longer than 20 mm were significantly related to restenosis (p < 0.001). CONCLUSION: The most important factor to explain restenosis was the immediate post-CAS residual stenosis and length of the plaque.