Impact of Balloon Guide Catheter Use on Clinical and Angiographic Outcomes in the STRATIS Stroke Thrombectomy Registry.

Background and Purpose- Mechanical thrombectomy has been shown to improve clinical outcomes in patients with acute ischemic stroke. However, the impact of balloon guide catheter (BGC) use is not well established. Methods- STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter study of patients with large vessel occlusion treated with the Solitaire stent retriever as first-line therapy. In this study, an independent core laboratory, blinded to the clinical outcomes, reviewed all procedures and angiographic data to classify procedural technique, target clot location, recanalization after each pass, and determine the number of stent retriever passes. The primary clinical end point was functional independence (modified Rankin Scale, 0-2) at 3 months as determined on-site, and the angiographic end point was first-pass effect (FPE) success rate from a single device attempt (modified Thrombolysis in Cerebral Infarction, ≥2c) as determined by a core laboratory. Achieving modified FPE (modified Thrombolysis in Cerebral Infarction, ≥2b) was also assessed. Comparisons of clinical outcomes were made between groups and adjusted for baseline and procedural characteristics. All participating centers received institutional review board approval from their respective institutions. Results- Adjunctive technique groups included BGC (n=445), distal access catheter (n=238), and conventional guide catheter (n=62). The BGC group had a higher rate of FPE following first pass (212/443 [48%]) versus conventional guide catheter (16/62 [26%]; P=0.001) and distal access catheter (83/235 [35%]; P=0.002). Similarly, the BGC group had a higher rate of modified FPE (294/443 [66%]) versus conventional guide catheter (26/62 [42%]; P<0.001) and distal access catheter (129/234 [55%]; P=0.003). The BGC group achieved the highest rate of functional independence (253/415 [61%]) versus conventional guide catheter (23/55 [42%]; P=0.007) and distal access catheter (113/218 [52%]; P=0.027). Final revascularization and mortality rates did not differ across the groups. Conclusions- BGC use was an independent predictor of FPE, modified FPE, and functional independence, suggesting that its routine use may improve the rates of early revascularization success and good clinical outcomes. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke).

BACKGROUND: Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation. METHODS: STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0-2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass. RESULTS: A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients (P<0.001). Clinical outcomes were better in the direct group, with 60.0% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06-1.79; P=0.02). Likewise, excellent outcome (modified Rankin Score 0-1) was achieved in 47.4% (236/498) of direct patients versus 38.0% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13-1.92; P=0.005). Mortality did not differ between the 2 groups (15.1% for direct, 13.7% for transfer; P=0.55). Intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but MT would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and MT performed 94 minutes earlier. CONCLUSIONS: In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke: Primary Results of the STRATIS Registry.

BACKGROUND AND PURPOSE: Mechanical thrombectomy with stent retrievers has become standard of care for treatment of acute ischemic stroke patients because of large vessel occlusion. The STRATIS registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) aimed to assess whether similar process timelines, technical, and functional outcomes could be achieved in a large real world cohort as in the randomized trials. METHODS: STRATIS was designed to prospectively enroll patients treated in the United States with a Solitaire Revascularization Device and Mindframe Capture Low Profile Revascularization Device within 8 hours from symptom onset. The STRATIS cohort was compared with the interventional cohort of a previously published SEER patient-level meta-analysis. RESULTS: A total of 984 patients treated at 55 sites were analyzed. The mean National Institutes of Health Stroke Scale score was 17.3. Intravenous tissue-type plasminogen activator was administered in 64.0%. The median time from onset to arrival in the enrolling hospital, door to puncture, and puncture to reperfusion were 138, 72, and 36 minutes, respectively. The Core lab-adjudicated modified Thrombolysis in Cerebral Infarction ≥2b was achieved in 87.9% of patients. At 90 days, 56.5% achieved a modified Rankin Scale score of 0 to 2, all-cause mortality was 14.4%, and 1.4% suffered a symptomatic intracranial hemorrhage. The median time from emergency medical services scene arrival to puncture was 152 minutes, and each hour delay in this interval was associated with a 5.5% absolute decline in the likelihood of achieving modified Rankin Scale score 0 to 2. CONCLUSIONS: This largest-to-date Solitaire registry documents that the results of the randomized trials can be reproduced in the community. The decrease of clinical benefit over time warrants optimization of the system of care. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Safety and effectiveness assessment of the surpass evolve (SEASE): a post-market international multicenter study.

BACKGROUND: Flow diverters are the first-line treatment for specific intracranial aneurysms (iA). Surpass Evolve (SE) is a new-generation 64-wire flow diverter with a high braid angle. Current literature on the SE is limited. We aimed to report the first international real-world experience evaluating the safety and effectiveness of the SE. METHODS: The Safety and Effectiveness Assessment of the Surpass Evolve (SEASE) was a multicenter retrospective international post-marketing cohort study including consecutive patients treated with SE for iAs between 2020 and 2022. Demographic, clinical, and angiographic data were collected. Primary effectiveness was independent core lab adjudicated complete occlusion rates (Raymond-Roy Class 1) at last follow-up. Primary safety were major ischemic/hemorrhagic events and mortality. RESULTS: In total, 305 patients with 332 aneurysms underwent SE implantation. The patients had a median age of 59 [50-67] years, and 256 (83.9%) were female. The baseline modified Rankin scale score was 0-2 in 291 patients (96.7%). Most aneurysms were unruptured (285, 93.4%) and saccular (309, 93.1%). Previous treatment was present in 76 (22.9%) patients. The median aneurysm size was 5.1 [3.4-9.0] mm, and the median neck width was 3.6 [2.7-5.1] mm. Most aneurysms were in the internal carotid artery C6 ophthalmic segment (126, 38.0%), followed by the communicating segment (58, 17.5%). At median 10.2 [6.4-12.9] months follow-up, 233 (73.0%) aneurysms achieved complete occlusion. After adjusting for confounders, complete occlusion remained consistent. Major stroke and procedure-related mortality were reported in 6 (2%) and 2 (0.7%) cases, respectively. CONCLUSION: These results demonstrate that SE has a consistently high effectiveness and favorable safety for the treatment of iAs.

Frequency-domain optical coherence tomography assessment of very late vascular response after carotid stent implantation.

Intravascular optical coherence tomography is a high-resolution invasive imaging modality that allows the evaluation of vascular responses after stent implantation in a micron-scale level. We describe for the first time two patients with very late vascular response after carotid artery stenting that exhibit two different patterns of low-signal intensity (LSI), "ill-appearing" neointima: the first patient shows layered LSI neointima leading to stent restenosis, coupled with the presence of intraluminal thrombus, whereas the second patient demonstrates another pattern of non-restenotic LSI stent strut coverage, suggestive of lipid laden neointima (ie, "neoatherosclerosis"), recently associated with stent failure in coronary arteries.

High variability in physician estimations of flow-diverting stent deployment versus PreSize Neurovascular software simulation: a comparison study.

BACKGROUND: Physician variablity in preoperative planning of endovascular implant deployment and associated inaccuracies have not been documented. This study aimed to quantify the variability in accuracy of physician flow diverter (FD) planning and directly compares it with PreSize Neurovascular (Oxford Heartbeat Ltd) software simulations. METHODS: Eight experienced neurointerventionalists (NIs), blinded to procedural details, were provided with preoperative 3D rotational angiography (3D-RA) volumetric data along with images annotated with the distal landing location of a deployed Surpass Evolve (Stryker Neurovascular) FD from 51 patient cases. NIs were asked to perform a planning routine reflecting their normal practice and estimate the stent's proximal landing using volumetric data and the labeled dimensions of the FD used. Equivalent deployed length estimation was performed using PreSize software. NI- and software-estimated lengths were compared with postprocedural observed deployed stent length (control) using Bland-Altman plots. NI assessment agreement was assessed with the intraclass correlation coefficient (ICC). RESULTS: The mean accuracy of NI-estimated deployed FD length was 81% (±15%) versus PreSize's accuracy of 95% (±4%), demonstrating significantly higher accuracy for the software (p<0.001). The mean absolute error between estimated and control lengths was 4 mm (±3.5 mm, range 0.03-30.2 mm) for NIs and 1 mm (±0.9 mm, range 0.01-3.9 mm) for PreSize. No discernable trends in accuracy among NIs or across vasculature and aneurysm morphology (size, vessel diameter, tortuousity) were found. CONCLUSIONS: The study quantified experienced physicians' significant variablity in predicting an FD deployment with current planning approaches. In comparison, PreSize-simulated FD deployment was consistently more accurate and reliable, demonstrating its potential to improve standard of practice.

Prospective study on embolization of intracranial aneurysms with the pipeline device (PREMIER study): 3-year results with the application of a flow diverter specific occlusion classification.

BACKGROUND: The pipeline embolization device (PED; Medtronic) has presented as a safe and efficacious treatment for small- and medium-sized intracranial aneurysms. Independently adjudicated long-term results of the device in treating these lesions are still indeterminate. We present 3-year results, with additional application of a flow diverter specific occlusion scale. METHODS: PREMIER (prospective study on embolization of intracranial aneurysms with pipeline embolization device) is a prospective, single-arm trial. Inclusion criteria were patients with unruptured wide-necked intracranial aneurysms ≤12 mm. Primary effectiveness (complete aneurysm occlusion) and safety (major neurologic event) endpoints were independently monitored and adjudicated. RESULTS: As per the protocol, of 141 patients treated with a PED, 25 (17.7%) required angiographic follow-up after the first year due to incomplete aneurysm occlusion. According to the Core Radiology Laboratory review, three (12%) of these patients progressed to complete occlusion, with an overall rate of complete aneurysm occlusion at 3 years of 83.3% (115/138). Further angiographic evaluation using the modified Cekirge-Saatci classification demonstrated that complete occlusion, neck residual, or aneurysm size reduction occurred in 97.1%. The overall combined safety endpoint at 3 years was 2.8% (4/141), with only one non-debilitating major event occurring after the first year. There was one case of aneurysm recurrence but no cases of delayed rupture in this series. CONCLUSIONS: The PED device presents as a safe and effective modality in treating small- and medium-sized intracranial aneurysms. The application of a flow diverter specific occlusion classification attested the long-term durability with higher rate of successful aneurysm occlusion and no documented aneurysm rupture. TRIAL REGISTRATION: NCT02186561.

The WOVEN trial: Wingspan One-year Vascular Events and Neurologic Outcomes.

BACKGROUND: Prior studies evaluating the Wingspan stent for treatment of symptomatic intracranial atherosclerotic disease have included patients with a spectrum of both on-label and off-label indications for the stent. The WEAVE trial assessed 152 patients stented with the Wingspan stent strictly by its current on-label indication and found a 2.6% periprocedural stroke and death rate. OBJECTIVE: This WOVEN study assesses the 1-year follow-up from this cohort. METHODS: Twelve of the original 24 sites enrolling patients in the WEAVE trial performed follow-up chart review and imaging analysis up to 1 year after stenting. Assessment of delayed stroke and death was made in 129 patients, as well as vascular imaging follow-up to assess for in-stent re-stenosis. RESULTS: In the 1-year follow-up period, seven patients had a stroke (six minor, one major). Subsequent to the periprocedural period, no deaths were recorded in the cohort. Including the four patients who had periprocedural events in the WEAVE study, there were 11 strokes or deaths of the 129 patients (8.5%) at the 1-year follow-up. CONCLUSIONS: The WOVEN study provides the 1-year follow-up on a cohort of 129 patients who were stented according to the current on-label use. It provides a more homogeneous patient group for analysis than prior studies, and demonstrates a relatively low 8.5% 1-year stroke and death rate in stented patients.

Safety of the APOLLO Onyx delivery microcatheter for embolization of brain arteriovenous malformations: results from a prospective post-market study.

BACKGROUND: Catheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs. METHODS: This was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded. RESULTS: A total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler-Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related. CONCLUSION: This study demonstrates the safety of Apollo for Onyx embolization of bAVMs. CLINICAL TRIAL REGISTRATION: CNCT02378883.

Technical note on endovascular treatment of concomitant carotid occlusion in large vessel occlusion stroke: The "single-cross" technique.

BACKGROUND: Emergent large vessel occlusive (ELVO) stroke secondary to underlying carotid occlusive disease is frequently encountered in endovascular ischemic stroke therapy and trials. Up to 29% of all cerebral vascular accidents are attributed to severe carotid occlusive disease, and recent interventional trials have demonstrated this occurrence in 18.6-32.2% of ELVO stroke. We present a novel technique using the stent retriever guide wire to expedite angioplasty and/or stent placement for associated carotid occlusive disease during mechanical thrombectomy of ELVO stroke. This technique utilizes the "waiting time" during stent retriever integration within the thrombus as an opportunity to initiate revascularization of the cervical carotid, using the deployed stent retriever guidewire as an ad hoc rapid exchange wire while the stentriever serves as a potential surrogate distal embolic protection device. We present 23 cases using this novel endovascular approach, which we have called the single-cross technique, as the cervical lesion is only traversed once during therapy. METHODS: A case series of 23 consecutive patients who underwent a novel endovascular technique for treating tandem ICA origin and intracranial occlusive lesions is presented. Endpoints measured were time to re-perfusion, rates of intracranial hemorrhage and clinical outcomes (mRS at 30 and 90 days). RESULTS: Average procedure time for revascularizing both the carotid and intracranial lesions was 52 min. A symptomatic ICH rate of 9% was observed. Seventy-four percent of patients had an mRS of 0-2 at follow-up. CONCLUSIONS: The single-cross technique appears to be a safe and effective option for treating tandem occlusive lesions in the setting of ELVO.

A Prospective Multicenter Trial of the TransForm Occlusion Balloon Catheter: Trial Design and Results.

BACKGROUND AND PURPOSE: Adjunctive treatments like balloon-assisted coil embolization (BACE) and stent-assisted coil embolization play a major role in the treatment of wide-neck and large intracranial aneurysms. The TransForm™ Occlusion Balloon Catheter (TOBC) registry is intended to evaluate the safety, efficacy, and efficiency of BACE using the TOBC. METHOD AND STUDY DESIGN: The TOBC registry is a prospective multicenter registry trial. Seven sites in the USA and 1 site in Spain participated and enrolled 81 patients. RESULTS: The performance and safety of the TOBC was evaluated based on scoring for different variables. Scores were measured using a semiquantitative rating scale (1 = excellent, 5 = poor). The mean scores for these variables were as follows: visibility under fluoroscopy, 1.8; ability to reach the intended site, 1.6; stability during first positioning, 1.5; stability during inflation, 1.6; stability during deflation, 1.6; ability to temporarily stop flow, 1.6; and ability to assist in coil embolization, 1.7. The mean inflation and deflation times were 4.9 and 5.6 s, respectively. Complete obliteration of the aneurysm (Raymond class I) was achieved in 69.4% of the BACE cases. Thrombus formation occurred in 4/81 (4.8%) of the cases. In all cases, the thrombus resolved with medications, no patient suffered an infarction, and an underlying hypercoagulable state from subarachnoid hemorrhage was considered a contributing factor. Vessel rupture occurred in 1/81 (1.2%) of the cases, but was unrelated to TOBC use. CONCLUSION: BACE using the TOBC is safe and effective. All variables assessed for performance showed good-to-excellent results.

Combined transarterial N-butyl cyanoacrylate and coil embolization of direct carotid-cavernous fistulas. Report of two cases.

The authors report two cases of traumatic carotid-cavernous fistulas treated successfully with combined N-butyl cyanoacrylate glue and coil embolization via a transarterial approach. In both cases complete occlusion of the fistula was achieved, with preservation of the parent carotid artery. Casting of the cavernous sinus with a liquid embolic agent was well tolerated and produced no complications of cranial nerve palsy. This technique provides interventionalists with yet another treatment option in these often complex cases.

Spontaneous intracranial arterial dissection in the young: diagnosis by CT angiography.

BACKGROUND: Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography) in the young. CASE PRESENTATION: We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the left internal carotid artery (confirmed by catheter arteriography). Studies for vasculitis, pro-thrombotic states, and defects of collagen were negative. CONCLUSION: Spontaneous carotid artery dissection is a potential cause of transient neurological symptoms and ischemic stroke in the pediatric population. Dynamic computed tomography appears to be a reliable diagnostic tool which can lead to early diagnosis.

Aneurysm Study of Pipeline in an Observational Registry (ASPIRe).

BACKGROUND AND OBJECTIVE: Few prospective studies exist evaluating the safety and efficacy of the Pipeline Embolization Device (PED) in the treatment of intracranial aneurysms. The Aneurysm Study of Pipeline In an observational Registry (ASPIRe) study prospectively analyzed rates of complete aneurysm occlusion and neurologic adverse events following PED treatment of intracranial aneurysms. MATERIALS AND METHODS: We performed a multicenter study prospectively evaluating patients with unruptured intracranial aneurysms treated with PED. Primary outcomes included (1) spontaneous rupture of the Pipeline-treated aneurysm; (2) spontaneous nonaneurysmal intracranial hemorrhage (ICH); (3) acute ischemic stroke; (4) parent artery stenosis, and (5) permanent cranial neuropathy. Secondary endpoints were (1) treatment success and (2) morbidity and mortality at the 6-month follow-up. Vascular imaging was evaluated at an independent core laboratory. RESULTS: One hundred and ninety-one patients with 207 treated aneurysms were included in this registry. The mean aneurysm size was 14.5 ± 6.9 mm, and the median imaging follow-up was 7.8 months. Twenty-four aneurysms (11.6%) were small, 162 (78.3%) were large and 21 (10.1%) were giant. The median clinical follow-up time was 6.2 months. The neurological morbidity rate was 6.8% (13/191), and the neurological mortality rate was 1.6% (3/191). The combined neurological morbidity/mortality rate was 6.8% (13/191). The most common adverse events were ischemic stroke (4.7%, 9/191) and spontaneous ICH (3.7%, 7/191). The complete occlusion rate at the last follow-up was 74.8% (77/103). CONCLUSIONS: Our prospective postmarket study confirms that PED treatment of aneurysms in a heterogeneous patient population is safe with low rates of neurological morbidity and mortality. Patients with angiographic follow-up had complete occlusion rates of 75% at 8 months.

Optical coherence tomography of the intracranial vasculature and Wingspan stent in a patient.

A 67-year-old man with medically refractory vertebrobasilar insufficiency and short segment occlusions of the intracranial vertebral arteries was treated with angioplasty and stent placement. Fifteen hours after the procedure the patient developed symptoms of posterior fossa ischemia and repeat angiography showed thrombus formation within the stent which was treated with thrombolytic and aggressive antiplatelet therapy. Angiography revealed lysis of the clot, but concerns regarding the mechanism of the thrombotic phenomenon prompted frequency-domain optical coherence tomography (FDOCT) assessment. FDOCT provided excellent visualization of the stent and vessel wall interactions, as well as excluding residual flow-limiting stenosis, obviating the need for further intervention. The potential utility of FDOCT in the evaluation of intracranial atherosclerotic disease and additional intracranial applications are discussed.

Recognition and importance of an infraoptic anterior cerebral artery: case report.

Although variations of the anterior cerebral artery (ACA)-anterior communicating artery complex are commonly identified on imaging studies, an infraoptic course of the ACA is exceedingly rare. What is believed to be the first case of an infraoptic course of the ACA discovered with MR angiography and further characterized with conventional angiography is presented. The high prevalence of associated aneurysms and the implications for surgical planning make preoperative recognition of this anomaly critical.

Pseudo-subarachnoid hemorrhage: a potential imaging pitfall associated with diffuse cerebral edema.

We report CT findings in seven patients with diffuse cerebral edema and increased attenuation in the basilar cisterns resembling subarachnoid hemorrhage. On the basis of autopsy (three cases) and lumbar puncture (four cases) findings, true subarachnoid hemorrhage was reasonably excluded. Pathophysiologic changes that occur with diffuse cerebral edema are explored, with proposed explanations for the appearance of a pseudo-subarachnoid hemorrhage.

Fluoroscopy fade for embolization of vein of Galen malformation.

A fluoroscopy fade technique in the embolization of a vein of Galen malformation in a 10-week-old infant is discussed herein. The availability of the fluoroscopy fade function eliminated the necessity of road mapping during the procedure and permitted minimal usage of contrast material and minimal radiation exposure for the patient. Techniques used during the embolization and the benefits of the fluoroscopy fade feature are also described.

Stereotactic radiosurgery associated neurotoxicity.

Stereotactic radiosurgery (SRS) is an evolving therapeutic modality for well demarcated intracranial lesions. Since the inception of stereotactic radiosurgery the types of parenchymal CNS lesions addressed by this mode of treatment has increased. All modern stereotactic radiosurgical procedures employ several common features. Patients are fitted with a stereotactic head frame or fiducial markers followed by radiographic imaging which allows for external reference points and three-dimensional mapping of the intracranial lesion. Armed with this information a highly conformal treatment plan is developed to deliver a high dose of radiation to a sharply defined target, with rapid dose fall-off outside the lesion volume. While an extremely effective therapeutic option, SRS is not without risk of neurotoxicity, with radiation necrosis being the most commonly recognized complication. The neurotoxic effects of SRS are reviewed and discussed.