Contrast-Induced Nephropathy in Ischemic Stroke Patients Undergoing Computed Tomography Angiography: CINISter Study.

GOAL: Computed tomography angiography (CTA) is a well-tolerated, noninvasive study of the intracranial vascular circulation; however, contrast-induced nephropathy (CIN) has been reported in 5%-7% of patients undergoing CTA. Limited studies have evaluated the risks of CIN in patients undergoing CTA. Our study was designed to evaluate the prevalence and risk factors for CIN in patients with ischemic stroke who receive a CTA. MATERIALS AND METHODS: Single-center, nested, case-control study of patients with ischemic stroke who received a CTA between June 18, 2012 and January 1, 2016. Patients were grouped based on development of CIN. FINDINGS: A total of 209 patients were included in the final analysis (178 controls, 31 cases). The prevalence of CIN during the time period studied was 14.8% (95% confidence interval [CI]: 10.2-20.2). A higher proportion of patients who developed CIN had a history of diabetes mellitus (37 [20.56%] versus 15 [48.39%]; P = .0009) and reported taking no medications prior to admission (35 [19.44%] versus 11 [35.48%]; P = .0458). However, a lower proportion of patients who developed CIN had a history of smoking (59 [32.78] versus 3 [9.68]; P = .0091). After statistical adjustment, only a history of diabetes (odds ratio [OR] 4.15 [95% CI: 1.765, 9.754), taking no medications prior to admission (OR 3.56 [95% CI: 1.417, 8.941]) and a self-reported history of smoking (OR 0.204 [95% CI: 0.057, 0.721]) remained associated with the development of CIN. CONCLUSIONS: Those patients with a history of diabetes mellitus or not taking medications prior to admission should be monitored closely for the development of contrast-induced nephropathy CIN.

Safety and efficacy of combined micropuncture and shallow angle femoral artery access for neurovascular angiography.

INTRODUCTION: The AXERA 2 low-angle vascular access device utilizes a dual arteriotomy mechanism in which the standard access tract is compressed by a vascular sheath inserted over the second, low-angle tract. It is unknown whether this device could be effectively used with 21-gauge micropuncture access, as the micropuncture introducer makes a larger arteriotomy than the 19-gauge needle provided with the AXERA 2 system. MATERIALS AND METHODS: A retrospective review was performed on 189 patients who underwent common femoral artery access for diagnostic cerebrovascular angiography using either combined micropuncture and AXERA 2 access or standard access with manual pressure hemostasis. Demographic and procedural data were reviewed along with complications related to vascular access and times to bed elevation, ambulation and discharge. RESULTS: Combined micropuncture and AXERA 2 access was performed on 110 patients and 79 patients had standard access. The AXERA device was successfully used in 91.8% of the cases. Demographic data, anticoagulant use and sheath sizes were similar between both subsets. Use of the AXERA 2 was associated with two bleeding complications (1.8%) compared with 10 (12.7%) with manual pressure hemostasis alone. Institution-specific protocol allowed shorter mean manual compression time, as well as shorter times to ambulation and discharge with the AXERA 2. CONCLUSIONS: Use of the AXERA 2 device with micropuncture access did not infer increased bleeding risk than standard arterial access in this patient series. The considerable incidence of device use failures suggests a learning curve associated with its use.

Comprehensive Overview of Contemporary Management Strategies for Cerebral Aneurysms.

Aneurysmal subarachnoid hemorrhage (SAH) remains an important health issue in the United States. Despite recent improvements in the diagnosis and treatment of cerebral aneurysms, the mortality rate following aneurysm rupture. In those patients who survive, up to 50% are left severely disabled. The goal of preventing the hemorrhage or re-hemorrhage can only be achieved by successfully excluding the aneurysm from the circulation. This article is a comprehensive review by contemporary vascular neurosurgeons and interventional neuroradiolgists on the modern management of cerebral aneurysms.

Enhanced, rapid occlusion of carotid and vertebral arteries using the AMPLATZER Vascular Plug II device: the Duke Cerebrovascular Center experience in 8 patients with 22 AMPLATZER Vascular Plug II devices.

OBJECTIVE: Therapeutic embolization of the common carotid artery (CCA), internal carotid artery (ICA), and vertebral artery (VA) is necessary in the treatment of a subset of chronic arteriovenous fistulas (AVFs), hemorrhages, highly vascularized neoplasms before resection, and giant aneurysms. There are currently no reports of the use of the AMPLATZER Vascular Plug II (AVP II) device to occlude the CCA, ICA, or VA. The objective of this article is to present the Duke Cerebrovascular Center experience using the AVP II device in neurointerventional applications. METHODS: This case series is a retrospective review of all of the cases at Duke University Hospital in which an AVP II device was used in the CCA, ICA, or VA up to September 2012. The AVP II device was often used in conjunction with embolization coils or as multiple AVP II devices deployed in tandem. RESULTS: During 2010-2012, 8 cases meeting criteria were performed. These included 2 chronic VA to internal jugular AVFs, 1 hemorrhagic CCA to internal jugular AVF secondary to invasive head and neck squamous cell carcinoma, 1 ICA hemorrhage secondary to invasive head and neck squamous cell carcinoma, 1 ICA hemorrhage secondary to trauma, 1 ruptured ICA aneurysm, 1 giant petrous ICA aneurysm, and 1 case of cervical vertebral sarcoma requiring preoperative VA embolization. Successful occlusion of the target vessel was achieved in all 8 cases. There was 1 major complication that consisted of a watershed distribution cerebral infarct; however, this was related to emergent occlusion of the ICA in the setting of intracranial hemorrhage and was not a problem intrinsic to the AVP II device. CONCLUSIONS: The AVP II device is relatively large, self-expanding vascular occlusion device that safely allows enhanced, rapid take-down of the CCA, ICA, and VA with low risk of distal migration.

Modern interventional management of stroke.

Acute ischemic stroke continues to be one of the leading causes of disability and death and is a financial burden to an already taxed health care system. Much research and investigation has been carried out over the past decade on various recanalization devices aimed at restoring cerebral blood flow. Despite the rapidly improving technical abilities of these devices, it has been difficult to demonstrate corresponding improved clinical outcomes. This article will describe the application of the most recent generation of these devices and briefly discuss the ongoing discrepancy between these technical achievements and stroke outcomes.

Evaluation of patient effective dose of neurovascular imaging protocols for C-arm cone-beam CT.

OBJECTIVE: The purpose of this study was threefold: to estimate the organ doses and effective doses (EDs) for seven neurovascular imaging protocols, to study the effect of beam collimation on ED, and to derive protocol-specific dose-area product (DAP)-to-ED conversion factors. MATERIALS AND METHODS: A cone-beam CT system was used to measure the organ doses for seven neurovascular imaging protocols. Two datasets were obtained: seven protocols without beam collimation (FOV, entire head) and four with beam collimation (FOV, from the base to the top of the skull). Measurements were performed on an adult male anthropomorphic phantom with 20 metal oxide semiconductor field-effect transistor (MOSFET) detectors placed in selected organs. The DAP values were recorded from the console. The EDs of five protocols were also estimated using Monte Carlo simulations software. The ED values were computed by multiplying measured organ doses to corresponding International Commission on Radiological Protection tissue-weighting factors. RESULTS: Without collimation, the EDs ranged from 0.16 to 1.6 mSv, and the DAP-to-ED conversion factors ranged from 0.035 to 0.076 mSv/Gy·cm(2). For the four protocols investigated with beam collimation, the ED was reduced by a factor of approximately 2, and the DAP-to-ED conversion factors were reduced by approximately 30%. For the five protocols also estimated with the Monte Carlo method, the estimated EDs were in agreement (< 20% deviation) with those determined by the MOSFET method. CONCLUSION: We have estimated ED for standard adult neuroimaging protocols in a 3D rotational angiography system. Our results provide a simple means of ED estimation using DAP console readings.

Developments on the horizon in the treatment of neurovascular problems.

The field of Interventional Neuroradiology and Endovascular Neurosurgery has seen much technical advancement in the past two decades, which has brought the specialty from its infancy as an alternative therapy to the current standing as near standard of care for many complex neurovascular pathologies. This past year is no exception with flow diverting stents and stent retriever devices aiming to make their mark on advanced treatments for intracranial aneurysms and ischemic stroke, respectively. This review article will focus on the development of these technologies, current data supporting their advantages and limitations, and a brief expert opinion on where these technologies may take the field in the next few years.

Is flow diversion the death of cerebral bypass and coiling/stent-assisted coiling for giant cavernous aneurysms? A critical review on comparative outcomes and ongoing clinical trials.

The classic surgical treatment for symptomatic giant aneurysms originating from the cavernous segment of the carotid artery has been either microsurgical direct clip-reconstruction or carotid occlusion followed by additional cerebral bypass for those patients who fail in a balloon test occlusion. Nevertheless the emergence of new endovascular techniques, especially flow-diverting devices, has promised to revolutionize the treatment of giant cavernous aneurysms, possibly avoiding major microsurgical operations. In this review the authors summarize the current "state-of-art" of treatment of giant cavernous aneurysms, comparing the overall outcomes, complications, morbidity and mortality rates of new flow-diverting devices in relation to traditional microsurgical series.

Visual complications after stent-assisted endovascular embolization of paraophthalmic and suprasellar variant superior hypophyseal aneurysms: the Duke Cerebrovascular Center experience in 57 patients.

OBJECTIVE: To review retrospectively experience with stent-assisted coiling of ophthalmic segment internal carotid artery (ICA) aneurysms to report outcome data and identify the rate of associated visual complications. METHODS: The Duke endovascular database was retrospectively reviewed to identify all ICA aneurysms treated with stent-assisted embolization between November 2002 and October 2009. Only aneurysms arising from the ophthalmic segment of the ICA and originating from the paraophthalmic or suprasellar variant superior hypophyseal artery were included. These aneurysms have the potential to create visual disturbances related to mass effect on the optic nerve or chiasm or to disrupt the ophthalmic artery. Chart review was performed to obtain clinical information, immediate incidence, and follow-up of aneurysm remnants and any visual complications. RESULTS: There were 63 aneurysms (48 paraophthalmic and 15 suprasellar variant superior hypophyseal) identified in 57 patients. The ophthalmic artery was preserved in all but two (3.5%) cases, neither of which resulted in visual deficits. One (1.8%) patient experienced transient acute visual disturbances, and two (3.5%) patients had delayed, persistent deficits. CONCLUSIONS: Stent-assisted embolization of ophthalmic segment ICA aneurysms is technically achievable and in our series did not appear to result in increased visual complications compared with coil embolization alone or surgical treatment.

Improved delivery of the Neuroform 3 stent: technical note.

BACKGROUND: Intracranial stents have expanded endovascular therapy to wide neck aneurysms whose dimensions and configurations are not amendable to coil embolization alone. Stents however have not eliminated all problems due to technical factors with their delivery systems. The Neuroform stent system is one of the most widely used for this purpose and has undergone several technical modifications to improve deliverability. Despite improvements in the delivery system there are still reports of failure of stent deployment with the Neuroform 3. Here a simple back table modification is described in which the stent is pushed several centimeters back into the delivery catheter from its manufactured location. This makes the catheter tip more flexible and in our experience improves navigation through vessel curvature and increases deployment rate. METHODS: Our institution's cerebrovascular database was reviewed retrospectively in compliance with institutional review board approval to identify all Neuroform 3 stents used for assistance with aneurysm embolization since the current stent design became clinically available. Records were reviewed to identify cases of failure of stent placement using the above described technical modification. RESULTS: 139 Neuroform 3 stents were placed at our institution for assistance with aneurysm embolization with the technique described above. Only three instances of failure of stent placement related to trackability of the delivery system were identified for a technical failure rate of 2.2%. CONCLUSIONS: A simple back table modification to the Neuroform 3 delivery system is described which in our single center experience may improve trackability and ultimately successful stent deployment.

Mechanical thrombectomy devices for endovascular management of acute ischemic stroke: Duke stroke center experience.

BACKGROUND: Mechanical thrombectomy devices are gaining popularity in large vessel occlusions where chemical thrombolysis is usually futile. MERCI, Multi-MERCI, Penumbra and SWIFT trails have elevated the status of mechanical thrombectomy from being a complementary treatment modality to mainstream stroke intervention. The aim of this study was to compare our immediate recanalization rates with available mechanical devices. MATERIALS AND METHODS: A retrospective review from March 2009 to August 2012 was performed on patients who underwent mechanical thrombectomy for large vessel occlusion. Cases where IATPA and/or balloon angioplasty was performed without mechanical thrombectomy were excluded from the study. Recanalization rates were assessed immediately post-procedure by follow-up angiography. TICI scores were used to quantify the extent of recanalization and the residual clot burden. RESULTS: Twenty two procedures were performed on 20 patients using Merci (MER):5; Penumbra (PEN):11; Solitaire-FR (SOL):6. Two patients underwent intervention using both Merci and Penumbra devices. The M:F ratio was 1.2:1. The most common vascular territory involved was the right MCA (9/20) followed by left MCA (5/20), left ICA (2/20), basilar (3/20) and vertebral arteries (1/20). The average door to needle time was 210 minutes [MER: 184.4; PEN: 249.2; SOL: 162]. Additional procedures were performed in 63.4% (14/22) of the patients [MER: 80% (4/5); PEN: 72.7% (8/11) and SOL: 33.3% (2/6)]. Vasospasm was observed in MER: 20% (1/5); PEN: 9.1% (1/11); SOL: 0% (0/6)]. Complete recanalization was achieved in 59.1% (13/22) [MER: 40% (2/5); PEN: 45.5% (5/11); SOL: 100% (6/6)]. The rate of complete recanalization was statistically significant for the Solitaire group vs. the MERCI group (P=0.0062) as well as the Penumbra group (0.0025). The average pre-procedure TICI was 0.4 [MER: 0.6; PEN: 0.3; SOL: 0.3], while the average post-procedure TICI was 2.5 [MER: 2.4; PEN: 2.3; SOL: 3.0]. CONCLUSIONS: The study reveals a higher rate of angiographic recanalization using the Solitaire-FR device, requiring a lesser number of passes and other associated procedures as compared to MERCI and Penumbra. Thus, Stentrievers (Solitaire-FR) are advantageous in faster device delivery and quick flow restoration. However, future prospective randomized large trials are required to confirm these early results.

Thromboembolic complications after Neuroform stent-assisted treatment of cerebral aneurysms: the Duke Cerebrovascular Center experience in 235 patients with 274 stents.

BACKGROUND: The Neuroform Stent has facilitated the endovascular treatment of wide-necked cerebral aneurysms. It is unknown which factors pose risks of thromboembolic events after stent placement. OBJECTIVE: This series is the largest single-center study reporting on the incidence of and factors influencing thromboembolic complications after Neuroform stent placement. METHODS: A total of 235 patients were treated with 274 Neuroform stents. The thromboembolic event rate was determined by imaging or clinical evidence of cerebrovascular accident within 90 days of stent placement; for patients with incomplete follow-up through chart review, telephone interviews were conducted. Analyses were performed to investigate patient factors that may be associated with stroke. RESULTS: Most aneurysms were unruptured; 30 patients (12.8%) presented with acute subarachnoid hemorrhage. Twelve patients of the 224 with follow-up (5.4%, 95% confidence interval: 2.4%-8.3%) demonstrated imaging or clinical evidence of a new thromboembolic event within 90 days of stent placement. There was a 3.1% thromboembolic rate for unruptured aneurysms and a 20% rate in patients with subarachnoid bleed. Hemorrhage was significantly associated with having a thromboembolic event (P = .002). There was a trend toward an increased thromboembolic event rate for patients with hypertension (P = .07). Larger stent caliber was significantly associated with a decreased thromboembolic event rate (P = .032). CONCLUSION: Our results suggest that the thromboembolic event rate associated with Neuroform stent use is low in unruptured aneurysms. In ruptured aneurysms, the complication rate is high, possibly partly related to restricted use of antiplatelet therapy. Stent size and hypertension may be associated with the risk of stroke, but additional studies are needed to confirm their significance.

A review of the management of posterior communicating artery aneurysms in the modern era.

BACKGROUND: Technical advancements have significantly improved surgical and endovascular treatment of cerebral aneurysms. In this paper, we review the literature with regard to treatment of one of the most common intra-cranial aneurysms encountered by neurosurgeons and interventional radiologists. CONCLUSIONS: Anterior clinoidectomy, temporary clipping, adenosine-induced cardiac arrest, and intraoperative angiography are useful adjuncts during surgical clipping of these aneurysms. Coil embolization is also an effective treatment alternative particularly in the elderly population. However, coiled posterior communicating artery aneurysms have a particularly high risk of recurrence and must be followed closely. Posterior communicating artery aneurysms with an elongated fundus, true posterior communicating artery aneurysms, and aneurysms associated with a fetal posterior communicating artery may have better outcome with surgical clipping in terms of completeness of occlusion and preservation of the posterior communicating artery. However, as endovascular technology improves, endovascular treatment of posterior communicating artery aneurysms may become equivalent or preferable in the near future. One in five patients with a posterior communicating artery aneurysm present with occulomotor nerve palsy with or without subarachnoid hemorrhage. Factors associated with a higher likelihood of recovery include time to treatment, partial third nerve deficit, and presence of subarachnoid hemorrhage. Both surgical and endovascular therapy offer a reasonable chance of recovery. Based on level 2 evidence, clipping appears to offer a higher chance of occulomotor nerve palsy recovery; however, coiling will remain as an option particularly in elderly patients or patients with significant comorbidity.

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.

Placement of inferior vena cava filters in bariatric surgical patients--possible indications and technical considerations.

BACKGROUND: Surgical treatment of the morbidly obese has assumed an increasingly important role in both the academic and community setting, while postoperative pulmonary embolism remains a devastating complication. Since the overall incidence remains low, the role for vena cava filter placement in this group is not yet well defined. In addition, the technical challenges and techniques for insertion have not been well-described. We present our experience with filter placement among patients with gastric bypass and the evolution of technique to facilitate safe placement in this group. METHODS: From 1995 to August 2003, 586 patients underwent gastric bypass for morbid obesity. Review of registries and records from this period was accomplished to identify patients at MUSC who underwent both the gastric bypass and placement of an inferior vena cava filter. 12 patients were identified by this method. RESULTS: Technical challenges with venous access and imaging are described. 6 patients were identified as potential high risk for thromboembolic complications and had a filter placed preoperatively with a mean postoperative stay of 5.3 days. The 6 patients who required filter placement in the postoperative period as part of the management of postoperative complications had a mean hospital stay of 24.5 days. There were no long-term complications associated with filter placement at a mean follow-up interval of 19 months. CONCLUSION: Inferior vena cava filter placement is not only feasible and safe for the morbidly obese individual undergoing gastric bypass, but should be strongly considered for patients with risk factors for thromboembolic complications or who experience postoperative complications requiring ICU stay or prolonged immobility.