New ischemic lesions on brain magnetic resonance imaging in patients with blunt traumatic cerebrovascular injury.

BACKGROUND: Patients with blunt cerebrovascular injuries are at risk of thromboembolic stroke. Although primary prevention with antithrombotic therapy is widely used in this setting, its effectiveness is not well defined and requires further investigation. The aim of this study was to evaluate the utility of magnetic resonance imaging (MRI)-detected ischemic brain lesions as a possible future outcome for randomized clinical trials in this patient population. METHODS: This prospective observational study included 20 adult blunt trauma patients admitted to a level I trauma center with a screening neck CTA showing extracranial carotid or vertebral artery injury. All subjects lacked initial evidence of an ischemic stroke and were managed with antithrombotic therapy and observation and then underwent brain MRI within 30 days of the injury to assess for ischemic lesions. The MRI scans included diffusion, susceptibility, and Fluid-attenuated Inversion Recovery (FLAIR) sequences, and were reviewed by two neuroradiologists blinded to the computed tomography angiography (CTA) findings. RESULTS: Eleven CTAs were done in the emergency department upon admission. There were 12 carotid artery dissections and 11 unilateral or bilateral vertebral artery injuries. Median interval between injury and MRI scan was 4 days (range, 0.1-14; interquartile range, 3-7 days). Diffusion-weighted imaging evidence of new ischemic lesions was present in 10 (43%) of 23 of the injured artery territories. In those injuries with ischemic lesions, the median number was 8 (range, 2-25; interquartile range, 5-8). None of the lesions were symptomatic. Blunt cerebrovascular injury was associated with a higher mean ischemic lesion count (mean count of 3.17 vs. 0.14, p < 0.0001), with the association remaining after adjusting for injury severity score (p < 0.0001). CONCLUSION: In asymptomatic blunt trauma patients with CTA evidence of extracranial cerebrovascular injury and treated with antithrombotic therapy, nearly half of arterial injuries are associated with ischemic lesions on MRI. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

Whole blood aggregometry prior to Pipeline embolization device treatment of intracranial aneurysms: defining an optimal platelet inhibition cutoff value for clopidogrel.

OBJECTIVEDual antiplatelet therapy is required for the treatment of intracranial aneurysms with the Pipeline embolization device (PED). Platelet function testing (PFT) is often used to assess the efficacy of the antiplatelet regimen prior to PED placement. The optimal impedance values for whole blood aggregometry in this setting have not been defined.METHODSA retrospective review of a prospectively maintained database was performed for the years 2011-2015 to identify patients with intracranial aneurysms treated with the PED who underwent pretreatment PFT using whole blood aggregometry. Antiplatelet therapy was not altered based on PFT results; all patients remained on standard doses of aspirin and clopidogrel. Clinical, radiographic, and laboratory data were analyzed to identify the optimal cutoff impedance value for clopidogrel responsiveness using the receiver operating characteristic curve and Youden's index.RESULTSForty-nine patients underwent 53 endovascular procedures for the treatment of 76 aneurysms using the PED. The majority of these aneurysms were located in the anterior circulation (90.8%) and affected the internal carotid artery (89.5%). Patients in 30 procedures (56.6%) were identified as clopidogrel responders based on the manufacturer cutoff value (< 6 Ω). Thromboembolic complications occurred in 13 (24.5%) procedures; patients in 6 (11.3%) cases were symptomatic and those in 3 (5.7%) cases had ischemic strokes. Eleven of the 13 (84.6%) thromboembolic complications occurred in clopidogrel nonresponders. An impedance value of ≥ 6 Ω was independently associated with thromboembolic complications. The optimal electrical impedance value was identified as ≥ 6 Ω (sensitivity 84.6%, specificity 70.0%, area under the curve 0.77) for identifying clopidogrel nonresponders.CONCLUSIONSThromboembolic complications are more common following PED placement in patients who do not respond adequately to clopidogrel. Clopidogrel nonresponders can be identified using pretreatment whole blood aggregometry. The optimal cutoff value to categorize a patient as a clopidogrel nonresponder when using whole blood aggregometry is ≥ 6 Ω.

Intra-arterial vasodilators for vasospasm following aneurysmal subarachnoid hemorrhage: a meta-analysis.

OBJECTIVE: The efficacy of intra-arterial vasodilators (IADs) for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) remains debatable. The objective of this meta-analysis was to pool estimates of angiographic and neurological response, clinical outcome, and mortality following treatment of vasospasm with IADs. METHODS: We searched PubMed, Embase, Scopus, Clinicaltrials.gov, Cochrane database, and CINAHL in December 2015 and August 2016. Studies reporting angiographic and neurological response, clinical outcome, and mortality following IAD treatment of vasospasm in 10 or more adults with aSAH were included. All established IADs were allowed. Two authors independently selected studies and abstracted the data. Mean weighted probabilities (MWP) were calculated using random effects model. RESULTS: Inclusion criteria were met by 55 studies (n=1571). MWP for immediate angiographic response to IAD treatment was 89% (95% CI 83% to 94%), post-IAD neurological improvement 57% (95% CI 49% to 65%), good outcome 66% (95% CI 60% to 71%), and mortality was 9% (95% CI 7% to 12%). After adjusting for publication bias, MWP for mortality was 5% (95% CI 4% to 7%). When transcranial Doppler (TCD) was used along with clinical deterioration for patient selection, rates of neurological response (64%) and good outcome (72%) were better. IADs were not superior to controls (balloon angioplasty or medical management). CONCLUSION: IAD treatment leads to a robust angiographic response and fair (but lower) rates of neurological response and good clinical outcome. Mortality was lower than the average reported in the literature. Rates of neurological response and good outcome were better when TCD was used for patient selection. Carefully designed studies are needed to compare IADs against medical management and balloon angioplasty.

Reliability assessment of the Biffl Scale for blunt traumatic cerebrovascular injury as detected on computer tomography angiography.

OBJECTIVE Blunt traumatic cerebrovascular injury (TCVI) represents structural injury to a vessel due to high-energy trauma. The Biffl Scale is a widely accepted grading scheme for these injuries that was developed using digital subtraction angiography. In recent years, screening CT angiography (CTA) has been used to identify patients with TCVI. The reliability of this scale, with injuries assessed using CTA, has not yet been determined. METHODS Seven independent raters, including 2 neurosurgeons, 2 neuroradiologists, 2 neurosurgical residents, and 1 neurosurgical vascular fellow, independently reviewed each presenting CTA of the neck performed in 40 patients with confirmed TCVI and assigned a Biffl grade. Ten images were repeated to assess intrarater reliability, for a total of 50 CTAs. Fleiss' multirater kappa (κ) and interclass correlation were calculated as a measure of interrater reliability. Weighted Cohen's κ was used to assess intrarater reliability. RESULTS Fleiss' multirater κ was 0.65 (95% CI 0.61-0.69), indicating substantial agreement as to the Biffl grade assignment among the 7 raters. Interclass correlation was 0.82, demonstrating excellent agreement among the raters. Intrarater reliability was perfect (weighted Cohen's κ = 1) in 2 raters, and near perfect (weighted Cohen's κ > 0.8) in the remaining 5 raters. CONCLUSIONS Grading of TCVI with CTA using the Biffl Scale is reliable.

Optical coherence tomography of traumatic aneurysms of the internal carotid artery: report of 2 cases.

The pathophysiology of extracranial traumatic aneurysm formation has not been fully elucidated. Intraarterial optical coherence tomography (OCT), an imaging modality capable of micrometer cross-sectional resolution, was used to evaluate patients presenting with saccular traumatic aneurysms of the internal carotid artery (ICA). Two consecutive trauma patients diagnosed with saccular traumatic aneurysms of the cervical ICA, per the institutional screening protocol for traumatic cerebrovascular injury, underwent digital subtraction angiography (DSA) with OCT. Optical coherence tomography demonstrated disruption of the intima with preservation and stretching of the more peripheral layers. In 1 patient the traumatic aneurysm was associated with thrombus formation and a separate, more proximal dissection not visible on CT angiography (CTA) or DSA. Imaging with OCT indicates that saccular traumatic aneurysms may develop from disruption of the intima with at least partial preservation of the media and adventitia. This provides in vivo evidence that saccular traumatic aneurysms result from a partial arterial wall tear rather than complete disruption. Interestingly, OCT was also able to detect arterial injury and thrombi not visible on CTA or DSA.

Clinical Presentation, Imaging, and Management of Complications due to Neurointerventional Procedures.

Neurointervention is a rapidly evolving and complex field practiced by clinicians with backgrounds ranging from neurosurgery to radiology, neurology, cardiology, and vascular surgery. New devices, techniques, and clinical applications create exciting opportunities for impacting patient care, but also carry the potential for new iatrogenic injuries. Every step of every neurointerventional procedure carries risk, and a thorough appreciation of potential complications is fundamental to maximizing safety. This article presents the most frequent and dangerous iatrogenic injuries, their presentation, identification, prevention, and management.

Carotid and vertebral injury study (CAVIS) technique for characterization of blunt traumatic aneurysms with reliability assessment.

Traumatic aneurysms occur in up to 20% of blunt traumatic extracranial carotid artery injuries. Currently there is no standardized method for characterization of traumatic aneurysms. For the carotid and vertebral injury study (CAVIS), a prospective study of traumatic cerebrovascular injury, we established a method for aneurysm characterization and tested its reliability. Saccular aneurysm size was defined as the greatest linear distance between the expected location of the normal artery wall and the outer edge of the aneurysm lumen ("depth"). Fusiform aneurysm size was defined as the "depth" and longitudinal distance ("length") paralleling the normal artery. The size of the aneurysm relative to the normal artery was also assessed. Reliability measurements were made using four raters who independently reviewed 15 computed tomographic angiograms (CTAs) and 13 digital subtraction angiograms (DSAs) demonstrating a traumatic aneurysm of the internal carotid artery. Raters categorized the aneurysms as either "saccular" or "fusiform" and made measurements. Five scans of each imaging modality were repeated to evaluate intra-rater reliability. Fleiss's free-marginal multi-rater kappa (κ), Cohen's kappa (κ), and interclass correlation coefficient (ICC) determined inter- and intra-rater reliability. Inter-rater agreement as to the aneurysm "shape" was almost perfect for CTA (κ = 0.82) and DSA (κ = 0.897). Agreements on aneurysm "depth," "length," "aneurysm plus parent artery," and "parent artery" for CTA and DSA were excellent (ICC > 0.75). Intra-rater agreement as to aneurysm "shape" was substantial to almost perfect (κ > 0.60). The CAVIS method of traumatic aneurysm characterization has remarkable inter- and intra-rater reliability and will facilitate further studies of the natural history and management of extracranial cerebrovascular traumatic aneurysms.

Endovascular tools available for the treatment of cerebrovascular disease.

This article reviews essential neurointerventional tools approved in the United States, including catheters and wires, coils, flow diverters, balloons, stents, and devices for mechanical thrombectomy and thrombolysis. These devices are the result of decades of technical development; this article will also briefly trace the evolution of these devices, with an emphasis on the most influential developments.

Resolution of diminished olfactory sensation after treatment of bilateral ophthalmic segment aneurysms with flow diversion: case report.

BACKGROUND AND IMPORTANCE: Olfactory tract dysfunction due to an unruptured intracranial aneurysm is rare. We present a case in which a patient with impaired olfaction related to bilateral internal carotid artery aneurysms experienced subjective and quantitative objective improvement of olfactory sensation after treatment of ophthalmic segment aneurysms with flow diversion. CLINICAL PRESENTATION: A 44-year-old woman presented with hyposmia and bilateral ophthalmic segment internal carotid artery aneurysms. The symptom of hyposmia, worsening over a period of several months, was suspected to be due to mass effect from bilateral unruptured ophthalmic segment aneurysms pressing on the olfactory tracts. Each aneurysm was treated with a Pipeline embolization device (PED). Follow-up angiography at 5 months showed occlusion of both aneurysms. The patient experienced subjective improvement in olfaction and complete objective resolution of her hyposmia as measured by the validated University of Pennsylvania Smell Identification Test (UPSIT). CONCLUSION: Intracranial aneurysms causing dysfunction of olfactory sensation due to mass effect upon the olfactory tract can be successfully treated with flow diversion. Flow diversion should be considered as one of the treatment options for patients with cranial nerve dysfunction due to unruptured intracranial aneurysms.

Improved diagnosis of actively bleeding aneurysm on CT angiography using delayed CT images.

Computed tomographic angiography (CTA) is being increasingly utilized in the non-invasive diagnosis of aneurysmal subarachnoid hemorrhage (SAH). There are emerging reports of diagnosis of active aneurysmal bleeding on CTA, furthering our understanding of imaging features of active extravasation on cross-sectional studies. We demonstrate imaging characteristics of two such cases of active contrast extravasation from intracranial aneurysms. Additionally, we demonstrate that delayed CT images greatly improve the confidence of this diagnosis by demonstrating pooling of contrast in the subarachnoid space. Prompt recognition and management can improve prognosis of this potentially lethal condition.

Clinical experience with Matrix2 360 degrees coils in the treatment of 100 intracranial aneurysms.

BACKGROUND: The M2-360 degrees is a recent class of aneurysm coil. This device combines the second generation of bioactive copolymer coating, which is intended to promote aneurysm fibrosis, with the "360 degrees " design, which is meant to improve uniformity and density of packing. This study evaluates the safety and angiographic stability of these devices. METHODS: This was a retrospective review of 86 consecutive patients with 100 intracranial aneurysms that were treated using M2-360 degrees s. Follow-up was done at 6 and 12 months. RESULTS: Seventy-eight aneurysms were coiled solely with M2-360 degrees s, and 22 aneurysms were treated with a combination of coils. In mixed-coil cases, the average percentage of coil volume consisting of M2-360 degrees coils was 78%. Procedure-related neurologic complications occurred in 6 patients (7%). Initial complete occlusion was obtained in 80 aneurysms. Of 76 aneurysms with 6-month angiographic follow-up, 4 (5.3%) revealed further occlusion, 54 (71.1%) were unchanged, and 18 (23.7%) showed recanalization. Of 38 aneurysms with 12-month follow-up, 1 (2.6%) revealed further occlusion, 23 (60.5%) were unchanged, and 14 (36.8%) showed recanalization. Six- and 12-month angiograms showed major recanalization (requiring further coiling) in 3.9% and 15.8% of cases, respectively. CONCLUSIONS: The risk of complications with M2-360 degrees -treated aneurysms is comparable with reports of other coils, indicating that M2-360 degrees s are relatively safe. Although the initial occlusion rate is higher than that in other coiling series, recanalization rates were similar to those obtained with other coil designs. This study does not demonstrate an advantage with M2-360 degrees s.

Legacy and current understanding of the often-misunderstood Foix-Alajouanine syndrome. Historical vignette.

Foix-Alajouanine syndrome has become a well-known entity since its initial report in 1926. The traditional understanding of this clinical syndrome is as a progressive spinal cord venous thrombosis related to a spinal vascular lesion, resulting in necrotic myelopathy. However, spinal venous thrombosis is extremely rare and not a feature of any common spinal vascular syndrome. A translation and review of the original 42-page French report revealed 2 young men who had presented with progressive and unrelenting myelopathy ultimately leading to their deaths. Pathological analysis demonstrated endomesovasculitis of unknown origin, including vessel wall thickening without evidence of luminal narrowing, obliteration of cord vessels, or thrombosis. Foix and Alajouanine also excluded the presence of intramedullary arteriovenous malformations. At the time, dural arteriovenous fistulas (dAVFs) had not been described, and therefore this type of lesion was not specifically sought. In retrospect, it seems possible that both patients had progressive myelopathy due to Type I dAVFs. In the decades since that original report, numerous authors have included spinal cord venous thrombosis as a central feature of Foix-Alajouanine syndrome. The inclusion of thrombosis in the clinical picture of this syndrome is not only incorrect but may leave one with the impression of therapeutic futility, thus possibly preventing successful surgical or endovascular therapy.

Ocular ischemic syndrome after occlusion of both external carotid arteries.

The ocular ischemic syndrome (OIS) has been reported in association with high-grade stenosis or occlusion of the common carotid artery (CCA) or internal carotid artery (ICA) but never with high-grade stenosis or occlusion of the external carotid artery (ECA) alone. We describe two patients who developed OIS with bilateral occlusion of the ECAs yet patent CCAs and ICAs. In one case, unilateral OIS followed consecutive bilateral carotid endarterectomies. In the other case, OIS developed spontaneously OU but was exacerbated in one eye after ipsilateral carotid endarterectomy (CE) in the setting of pre-existing contralateral ECA occlusion. In some individuals, the ECA is the primary source of arterial blood flow to the eye. Because of this fact, the endarterectomy surgeon must avoid causing ECA occlusion by meticulously removing not only the ICA plaque, but also the entire ECA plaque.

Percutaneous ethanol sclerotherapy for vascular malformations in the head and neck.

Vascular malformations are frequent in the head and neck. In addition to the occasional devastating cosmetic effects of large vascular malformations, some may cause significant functional impairment by encroaching on the eye, tongue, or throat. Large lesions may produce a breakdown of skin or mucosa, with resultant leakage of blood or fluid and possible infection in the lesions and surrounding tissues. Arteriovenous malformations, in particular, may develop massive bleeding spontaneously or with minor trauma. Numerous treatment options are available for treatment of these lesions. Surgical excision is the traditional treatment for vascular malformations in the head and neck. However, some lesions may be difficult to remove when they permeate and envelop normal structures, such as the facial nerve, and a less invasive mode of therapy may prevent damage to these normal structures. Percutaneous sclerotherapy was developed as a minimally invasive treatment modality for these lesions. It has also proved helpful as a preoperative adjunctive treatment of these lesions to reduce surgical blood loss and to delineate the surgical extent of resection.

Perfusion CT for head and neck tumors: pilot study.

BACKGROUND AND PURPOSE: Differentiation of malignant from benign head and neck lesions is often very difficult on imaging studies, especially in patients with treated cancer. We evaluated the feasibility and reproducibility of perfusion CT (CTP) after enhanced head and neck CT and attempted to differentiate benign from malignant processes. METHODS: CTP was attempted in 17 patients after head and neck contrast-enhanced CT. Data were postprocessed by using deconvolution-based perfusion analysis. Ipsilateral and contralateral internal, external, and common carotid arteries were used as arterial input vessels. Postprocessing-generated maps showed mean transit time (MTT), blood volume, blood flow, and capillary permeability surface product. Two readers independently placed regions of interest through the primary site, salivary glands, thyroid gland, paraspinous muscles, muscles of mastication, sternocleidomastoid muscle, base of tongue, and subcutaneous fat. One reader repeated the measurements on separate dates. Data were statistically analyzed, and histologic specimens were obtained. RESULTS: CTP was not possible in four patients, and one was lost to follow-up. Of the remaining 12, five had cancer, and seven had benign processes. We found no significant interreader or intrareader differences and no significant difference between various input vessels. Differentiation between malignant and nonmalignant lesions was most reliable by using MTTs. Measurements were comparable to those in the literature. CONCLUSION: CTP after enhanced head and neck CT is feasible, except perhaps at the laryngeal level. It appears to be reader independent and reproducible regardless of the input vessel. CTP shows promise in distinguishing benign and malignant processes, primarily by means of MTTs.

Ophthalmic artery occlusion secondary to radiation-induced vasculopathy.

A 35-year-old man with neurofibromatosis type 1 (NF1) had a left ophthalmic artery occlusion that caused no light perception OS 28 years after having been treated with external beam radiation therapy for a presumed glioma of the right optic nerve and chiasm. Clinical and imaging findings were consistent with radiation-induced cerebral vasculopathy. This ophthalmic complication has never been reported, despite the common occurrence of severe carotid-ophthalmic artery junction stenosis after radiation in NF1 patients. Even though modern radiation techniques limit collateral damage, this modality should be used with discretion in NF1 patients, given the vulnerability of their immature cerebral vasculature to radiation.

Facial and trigeminal neuropathies in cavernous sinus fistulas.

Three patients with carotid-cavernous fistulas had prominent ipsilateral facial nerve neuropathy. One patient also had ipsilateral third division trigeminal neuropathy, manifesting as painful trismus and lower facial numbness. Rarely reported in carotid-cavernous fistula, these neuropathies may occur when there is substantial drainage of the fistula into a dilated inferior petrosal sinus. Closure of the fistula in two cases resulted in full recovery of the neuropathies within weeks to months. The neuropathies may be caused by ischemia from an unfavorable arteriovenous flow gradient, venous compression, or secondary inflammation.

Cerebral perfusion CT: technique and clinical applications.

Perfusion computed tomography (CT) is a relatively new technique that allows rapid qualitative and quantitative evaluation of cerebral perfusion by generating maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). The technique is based on the central volume principle (CBF = CBV/MTT) and requires the use of commercially available software employing complex deconvolution algorithms to produce the perfusion maps. Some controversies exist regarding this technique, including which artery to use as input vessel, the accuracy of quantitative results, and the reproducibility of results. Despite these controversies, perfusion CT has been found to be useful for noninvasive diagnosis of cerebral ischemia and infarction and for evaluation of vasospasm after subarachnoid hemorrhage. Perfusion CT has also been used for assessment of cerebrovascular reserve by using acetazolamide challenge in patients with intracranial vascular stenoses who are potential candidates for bypass surgery or neuroendovascular treatment, for the evaluation of patients undergoing temporary balloon occlusion to assess collateral flow and cerebrovascular reserve, and for the assessment of microvascular permeability in patients with intracranial neoplasms. This article is a review of the technique, clinical applications, and controversies surrounding perfusion CT.

Carotid perfusion CT with balloon occlusion and acetazolamide challenge test: feasibility.

Carotid balloon test occlusion (BTO) is used to assess the collateral circulation and cerebrovascular reserve in patients in whom carotid artery occlusion is contemplated. Eight patients in whom the test was successful were evaluated with perfusion computed tomography (CT) in the resting state and after acetazolamide challenge. Three of the patients showed symmetric blood flow and normal response to acetazolamide. One of them underwent permanent carotid occlusion and did not develop any delayed ischemic stroke. The remaining five patients showed asymmetric blood flow. One of them had markedly low blood flow and abnormal response to acetazolamide. The patient developed ipsilateral hemispheric stroke following permanent carotid occlusion after the superficial temporal artery to middle cerebral artery bypass graft occluded. In the other four patients, the steal phenomenon was seen in ipsilateral and contralateral hemispheres. Although definitive quantitative values for perfusion CT are not yet standardized, it may be feasible to predict that the patients with symmetric blood flow and normal acetazolamide-enhanced challenge test results will do well after permanent carotid occlusion. Patients with asymmetric blood flow and abnormal response to the acetazolamide challenge test may require a revascularization procedure to protect them from delayed ischemic stroke.