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Acute carotid terminus occlusion (CTO) is responsible for up to 5% of acute ischemic strokes secondary to emergent large vessel occlusion (ELVO) and up to 20% of acute internal carotid artery (ICA) occlusions.1 The term "CTO" has also been used to describe occlusions in the supra-clinoid segment or at the bifurcation of the ICA. Compared to other ELVOs, patients with CTO present with higher stroke severity and larger infarct volume, likely to be a result of disruption of direct Circle of Willis collaterals across the anterior communicating artery (AComA) and posterior communicating artery (PComA).2,3 Similary, CTO is usually associated with worse prognosis compared to other ELVOs in general. With regard to response to treatment, previous studies have reported significantly lower recanalization rates with intravenous alteplase with CTO compared to M1 segment occlusion. With regard to the safety and efficacy of mechanical thrombectomy, prior reports provide conflicting results with some reporting lower successful recanalization rates with CTO compared to M1 occlusion, and others reporting similar results. In our experience, we have found that successful recanalization of CTO can be achieved with a similar approach to M1 occlusions utilizing a direct aspiration first pass technique (ADAPT).3,4 Herein, we present a case of CTO for which we performed mechanical thrombectomy using ADAPT. This procedure was an emergent standard of care procedure for which a consent was not required and so not obtained.

As capabilities for endovascular treatment of intracranial vascular pathologies continue to expand, the need for access to the distal internal carotid artery with rigid support catheter systems continues to increase. One of the dominant factors limiting this access is patient anatomy, specifically vessel tortuosity. Increased tortuosity of the carotid siphon is a frequently encountered anatomic variant and may complicate endovascular procedures in adults and children.1,2 Failed attempts to navigate the carotid siphon with a distal access catheter carry a risk of vessel injury and treatment failure. For this reason, techniques that aid in supporting safe advancement of a distal access catheter across a tortuous carotid siphon are essential.3,4 In this video, we demonstrate 2 ways in which this may be accomplished. The first technique uses a larger diameter microcatheter, such as the AXS Offset catheter (Stryker, Kalamazoo, Michigan), to increase support for the distal access catheter, while the second uses a buddy wire technique to accomplish this increased support. Both of these techniques can help increase the safety of navigating a tortuous carotid siphon and increase the likelihood of successful treatment. The procedures shown were performed with the informed consent of the patients.

Since the International Subarachnoid Aneurysm Trial,1 endovascular treatment has been the favored treatment for appropriate ruptured intracranial aneurysms. While our endovascular technology has advanced to allow us to treat the majority of intracranial aneurysms, simple coil embolization is still the most common modality. This video demonstrates the fundamentals of aneurysm catheterization and coiling for safe treatment. In addition, the set-up and devices are detailed. This video is to add to the library of basic techniques that will aid a large number of practitioners. This patient consented to endovascular treatment. The video demonstrates endovascular coil embolization of a posterior communicating artery aneurysm in a 76-yr-old female who presented with a subarachnoid hemorrhage. Image of biplane suite in video used courtesy of Siemens Medical Solutions USA, Inc. Illustration at 5:12 reprinted from Yasargil MG, et al, Microneurosurgery IV B, p. 9, Thieme, New York, 1995.

Vascular access for cerebral angiography has traditionally been performed via the common femoral artery. It is crucial to obtain safe access to prevent complications that could lead to limb ischemia, groin hematoma, or retroperitoneal hematoma. This is especially true in neurointervention as many patients are anticoagulated or have received intravenous thrombolytics prior to their intervention. Special attention to anatomic landmarks, both grossly and radiographically, can help to assure safe access. The patient consented for this procedure. This video details rapid but safe femoral artery access in a patient undergoing emergent thrombectomy.

No proven medical therapy exists for the treatment of moyamoya disease. Case reports have suggested that calcium channel blockers may be beneficial, potentially improving cerebral blood flow through a vasodilatory effect. The first objective of this pilot study was to prospectively evaluate whether intraarterial nitroglycerin, a potent vasodilator, could improve angiographic cerebral circulation in moyamoya patients. The second objective was to monitor the safety profile of transdermal nitroglycerin in our cohort of patients. Intraarterial nitroglycerin was infused in five patients with moyamoya disease at escalating doses. Angiography was performed before and after the nitroglycerin infusion. Pre- and post-infusion angiograms were compared for angiographic improvement. The contralateral side was used as an internal control in patients with unilateral moyamoya disease. The patients were then placed on a transdermal nitroglycerin patch and followed with serial neurological exams, blood pressure measurements, and either follow-up angiography or single photon emission computed tomography scans. All five patients had evidence of angiographic improvement after nitroglycerin infusion in the affected arteries, but no change was identified in the control arteries of patients with unilateral disease. No patient had adverse effects from either intraarterial or transdermal nitroglycerin. This small pilot study demonstrates angiographic improvement after intraarterial nitroglycerin in affected moyamoya arteries, but not in control arteries in the same patients, if present. There were no complications associated with transdermal nitroglycerin in these patients.

Object Foramen ovale (FO) puncture allows for trigeminal neuralgia treatment, FO electrode placement, and selected biopsy studies. The goals of this study were to demonstrate the anatomical basis of complications related to FO puncture, and provide anatomical landmarks for improvement of safety, selective lesioning of the trigeminal nerve (TN), and optimal placement of electrodes. Methods Both sides of 50 dry skulls were studied to obtain the distances from the FO to relevant cranial base references. A total of 36 sides from 18 formalin-fixed specimens were dissected for Meckel cave and TN measurements. The best radiographic projection for FO visualization was assessed in 40 skulls, and the optimal trajectory angles, insertion depths, and topographies of the lesions were evaluated in 17 specimens. In addition, the differences in postoperative pain relief after the radiofrequency procedure among different branches of the TN were statistically assessed in 49 patients to determine if there was any TN branch less efficiently targeted. Results Most severe complications during FO puncture are related to incorrect needle placement intracranially or extracranially. The needle should be inserted 25 mm lateral to the oral commissure, forming an approximately 45° angle with the hard palate in the lateral radiographic view, directed 20° medially in the anteroposterior view. Once the needle reaches the FO, it can be advanced by 20 mm, on average, up to the petrous ridge. If the needle/radiofrequency electrode tip remains more than 18 mm away from the midline, injury to the cavernous carotid artery is minimized. Anatomically there is less potential for complications when the needle/radiofrequency electrode is advanced no more than 2 mm away from the clival line in the lateral view, when the needle pierces the medial part of the FO toward the medial part of the trigeminal impression in the petrous ridge, and no more than 4 mm in the lateral part. The 40°/45° inferior transfacial–20° oblique radiographic projection visualized 96.2% of the FOs in dry skulls, and the remainder were not visualized in any other projection of the radiograph. Patients with V1 involvement experienced postoperative pain more frequently than did patients with V2 or V3 involvement. Anatomical targeting of V1 in specimens was more efficiently achieved by inserting the needle in the medial third of the FO; for V2 targeting, in the middle of the FO; and for V3 targeting, in the lateral third of the FO. Conclusions Knowledge of the extracranial and intracranial anatomical relationships of the FO is essential to understanding and avoiding complications during FO puncture. These data suggest that better radiographic visualization of the FO can improve lesioning accuracy depending on the part of the FO to be punctured. The angles and safety distances obtained may help the neurosurgeon minimize complications during FO puncture and TN lesioning.

BACKGROUND The most common presenting symptom for unruptured intracranial aneurysms (UIAs) is headache (HA). However, most experts believe that UIAs associated with HAs are unrelated and incidental. OBJECTIVE To analyze the incidence and characterization of HAs in patients with UIAs before and after treatment with either surgical clipping or endovascular embolization. METHOD We prospectively determined the presence, sidedness, and severity of HAs preoperatively in patients who presented to the senior author with a UIA. A validated, quantitative 11-point HA pain scale was used in all patients. The same HA assessments were performed again on these patients an average of 32.4 months postoperatively. RESULTS In this study, 92.45% (n = 53) of patents for whom we were able to obtain both a preoperative and postoperative pain score had an improvement in their HAs. The average quantitative HA score was 5.87 preoperatively vs 1.39 postoperatively (P < .001). There was no relationship found between the following: (1) HA severity vs aneurysm size, (2) sidedness of aneurysm vs sidedness of HA, and (3) HA improvement after surgical vs endovascular treatment. CONCLUSION This study suggests that surgical and endovascular treatment of a UIA is associated with dramatic improvement in self-reported HA score an average of 32.4 months postoperatively.

Objective A steel-reinforced and a nitanol-reinforced microcatheter are both approved for use with Onyx HD-500 embolization of intracranial aneurysms. The biomechanical behavior of these catheters when used with high viscosity embolic liquids is poorly understood. We performed biomechanical laboratory testing and examined our clinical experience to identify situations where one catheter might have an advantage over the other. Methods The catheters were tested for detachment force from aneurysm cast, burst pressure, burst location, and pressure under dynamic delivery pressure. The results were compared using ANOVA. Results The average detachment forces for the Echelon 10, 14, and Rebar 14 catheters were 97.6, 76.825, and 62.6 g, respectively (p=0.023). The average burst pressures for the Echelon 10, 14, and Rebar 14 were 1108, 1213, and 1365 psi, respectively (p=0.003). The average burst location was 26.0, 20.0, and 4.5 mm, respectively, from the tip (p=0.035). There was no significant difference regarding burst location (p=0.39). The delivery pressures of the catheters were not significant (p=0.98). Two cases are presented that illustrate the importance of these findings and how they can be incorporated into practice. Conclusion The lower detachment force of the Rebar 14 makes it ideal for liquid embolization, but its stiffness makes it less desirable for accessing smaller aneurysms or navigating tortuous anatomy. The Echelon 10 should be avoided unless it is the only catheter that can access an aneurysm because of small size or tortuous anatomy. In such cases, the higher detachment force suggests a stent should be in place to prevent the cast from being destabilized.

Object Vasospasm is one of the leading causes of morbidity and death following aneurysmal subarachnoid hemorrhage (SAH). Many patients suffer devastating strokes despite the best medical therapy. Endovascular treatment is the last line of defense for cases of medically refractory vasospasm. The authors present a series of patients who were treated with a prolonged intraarterial infusion of verapamil through an in-dwelling microcatheter. Methods Over a 1-year period 12 patients with medically refractory vasospasm due to aneurysmal SAH were identified. Data were retrospectively collected, including age, sex, Hunt and Hess grade, Fisher grade, aneurysm location, aneurysm treatment, day of the onset of vasospasm, intracranial pressure, mean arterial pressures, intraarterial treatment of vasospasm, dosages and times of verapamil infusion, presence of a new ischemic area on CT scan, modified Rankin scale score at discharge and at the last clinical follow-up, and discharge status. Results Twenty-seven treatments were administered. Between 25 and 360 mg of verapamil was infused per vessel (average dose per vessel 164.6 mg, range of total dose per treatment 70–720 mg). Infusion times ranged from 1 to 20.5 hours (average 7.8 hours). The number of treated vessels ranged from 1 to 7 per patient. The number of treatments per patients ranged from 1 to 4. There was no treatment-related morbidity or death. Blood pressure and intracranial pressure changes were transient and rapidly reversible. Among the 36 treated vessels, prolonged verapamil infusion was completely effective in 32 cases and partially effective in 4. Only 4 vessels required angioplasty for refractory vasospasm after prolonged verapamil infusion. There was no CT scanning evidence of new ischemic events in 9 of the 12 patients treated. At last clinical follow-up 6–12 months after discharge, 8 of 11 patients had a modified Rankin Scale score ≤2. Conclusions Prolonged intraarterial infusion of verapamil is a safe and effective treatment for medically refractory severe vasospasm and reduces the need for angioplasty in such cases.

Background Embolization of intracranial arteriovenous malformations (AVMs) is generally a preoperative adjunctive procedure in the USA. However, sometimes embolization can result in complete angiographic obliteration of the AVM. There is significant controversy regarding the best management strategy for this subset of patients. There is a scarcity of literature predicting which embolized, angiographically obliterated AVMs are likely to recur and which ones are cured. We present our series of patients with complete obliteration of their AVMs from embolization. Methods A prospectively maintained database identified 122 patients who underwent embolization of an intracerebral pial AVM with liquid embolics. Eighteen patients (15%) achieved complete angiographic obliteration of the AVM with embolization. We followed several parameters to assess possible predictors of recurrence. Results Fifteen of 18 patients (83%) had angiographic/anatomical follow-up to assess for AVM recurrence and 3 (17%) refused angiographic follow-up. Three patients underwent surgical resection with intraoperative angiography despite complete AVM obliteration with embolization alone. Thirteen of the 15 (87%) patients with follow-up remained obliterated at time of follow-up, and all of these patients had an embolic cast that had a similar morphology to the AVM nidus. Two of 15 patients (13%) had AVM recurrence, both of whom had incomplete embolic nidal opacification (proximal pedicle embolization). Conclusions A minority of intracranial AVMs can be safely obliterated with stand-alone embolization. Proximal occlusion of feeding arteries appears to be associated with recurrence. Prospective studies with longer follow-up and larger patient numbers are necessary.

Background A hybrid guide catheter mates the traditional strong guide catheter with a thin, soft distal tip, allowing placement further into the distal cervical or proximal cranial circulation. Case Description We present 5 cases in which traditional guide catheters were unable to successfully navigate tortuous anatomy or provide stable support for intervention. Conclusion Hybrid guide catheters provided safe, stable support for successful treatment. Hybrid guide catheters allow for treatment for patients who previously were not candidates for neuroendovascular surgery.

Many treatments for posttraumatic, skull base aneurysms have been described. Eight months after an all-terrain-vehicle accident, this 12-year-old girl presented with right-side Horner syndrome caused by a 33 × 19–mm internal carotid artery aneurysm at the C-1 level. We chose to treat the aneurysm with a new liquid embolic agent for wide-necked, side-wall aneurysms (Onyx HD 500). We felt this treatment would result in less morbidity than surgery and was less likely to occlude the parent artery than placement of a covered stent, especially in a smaller artery in a pediatric patient. Liquid embolic agents also appear to be associated with a lower chance of recanalization and lower cost compared with stent-assisted coil embolization. After the patient was treated with loading doses of aspirin, clopidogrel bisulfate, and heparin, 99% of the aneurysm was embolized with 9 cc of the liquid embolic agent. There were no complications, and the patient remained neurologically stable. Follow-up angiography revealed durable aneurysm occlusion after 1 year. The cost of Onyx was less than the cost of coils required for coil embolization of similarly sized intracranial aneurysms at our institution. Liquid embolic agents can provide a safe, efficacious, and cost-effective approach to treatment of select giant, posttraumatic, skull base aneurysms in pediatric patients.

Object The aim of this study was to determine the anatomical limitations of the transcallosal transchoroidal approach to the third ventricle. Methods Twenty-six formalin-fixed specimens were studied. Sagittal dissections were used to determine the anatomical relationships of the foramen of Monro, the angle of approach to landmarks, and placement of a callosotomy. Lateral ventricular dissections were performed to quantitate the forniceal anatomy. Results The foramen of Monro was found 1.07 ± 0.11 cm superior and slightly anterior to the mammillary bodies, 1.48 ± 0.16 cm posterosuperior to the optic recess, and 2.26 ± 0.16 cm anterosuperior to the aqueduct. Relative to the genu, a callosal incision 2.64 ± 0.53 cm long and angled 37 ± 4.3° anterior was needed to access the aqueduct, and an incision 4.92 ± 0.71 cm long and angled 49 ± 7.4° posterior was needed to access the optic recess. The fornix progressively widened within the lateral ventricle, from 1.25 ± 0.63 mm at the foramen of Monro to > 7 mm at 2 cm behind the foramen. Three zones of exposure were identified, requiring unique craniotomies, callosotomies, and angles of approach. The major limiting factors in the approach included the columns of the fornix anteriorly, the width of the fornix posteriorly, and the draining veins of the parietal cortex. The choroidal fissure opening was limited to 1.5 cm posterior to the foramen of Monro; this limited opening created an aperture effect that required an anterior-to-posterior angle, an anterior craniotomy, and an anteriorly placed callosotomy to access the posterior landmarks. In contrast, a posterior-to-anterior angle, posteriorly placed craniotomy, and posteriorly placed callosotomy were required to access anterior landmarks. Conclusions The transcallosal transchoroidal approach was ideally suited to access the foramen of Monro and the middle and posterior thirds of the third ventricle. Exposure of the anterior third ventricle was limited by the columns of the fornix and by the presence of parietal cortical draining veins.

Objective Endovascular treatment of intracranial aneurysms is less invasive than surgical repair but poses a higher risk for aneurysm recurrence, which may necessitate retreatment, thus adding to the long-term risk. Cerebrovascular neurosurgeons from 8 institutions in the United States and Puerto Rico collaborated to assess the risk of retreatment for residual or recurrent aneurysms after the initial endovascular coiling. Methods Data were prospectively recorded for 311 patients with coiled intracranial aneurysms who underwent 352 retreatment procedures after angiographic or clinical recurrence (hemorrhage after initial coiling). Results analyzed included procedural complications and procedure-related morbidity. Morbidity was classified as major (modified Rankin scale score > 3) or minor, and temporary ( 30 days). Results Retreatment mortality was 0.85% per procedure and 0.96% per patient. Treatment-related rates were 0.32% per patient (0.28% per procedure) for permanent or temporary major disability; 1.29% for permanent minor disability (1.14% per procedure); and 1.61% for temporary minor disability (1.42% per procedure). Total risk for death or permanent major disability was 1.28% per patient and 1.13% per procedure. Conclusion Retreatment poses a low risk for patients with recurrences of intracranial aneurysms after initial coiling; this risk is smaller than that posed by the initial endovascular therapy. The risk of disability associated with retreatment for aneurysm recurrence after coiling must be considered prospectively in the choice of treatment but with the recognition that its effects are low in the overall management risk.

Object Brain mapping aims to localize neurological function to specific regions of the human brain. Preoperative endovascular brain mapping (PEBM) is a novel approach that allows clear visualization of nonfunctional (silent) brain parenchyma in real time during a resection. It has potential to improve neurosurgical guidance because brain shift does not alter the maps, and the map is visualized directly on the brain in situ rather than on a nearby image. Therefore, the risk of a new neurological deficit should be reduced. The authors report the first PEBM approach that combines selective molecular targeting of brain endothelium with multispectral (optical) imaging in preclinical animal models. Methods Sprague-Dawley rats and New Zealand white rabbits were selectively catheterized, and a fluorescein isothiocyanate–derivatized tomato lectin–based imaging probe was administered into the carotid artery or posterior cerebral artery, measuring < 500 μm in diameter. After binding/uptake of the imaging probe, and removal of unbound probe, a craniotomy was performed to directly visualize the “brain map.” Results Selective localization of the imaging probe to the right hemisphere in rats or right posterior cerebral artery in rabbits was clearly visualized after craniotomy. Cross-sections of stained capillaries demonstrated that the imaging probe did not cause vascular occlusion. Gross regional selectivity of the imaging probe was documented by multispectral molecular imaging of intact brains, with discrete localization and endothelium-directed targeting validated by histological examination. Conclusions The authors have demonstrated the first molecular endothelium-targeted approach to PEBM that does not require manipulation of the intact blood-brain barrier or result in vascular occlusion. Furthermore, the presented multispectral molecular imaging technique appears to be a suitable methodology for the generation of region-selective brain maps of vascularized brain parenchyma. Further refinement of the PEBM approach, as well as the development of improved imaging probes, may result in clinical advancement of PEBM where direct visual discrimination of nonfunctional silent brain parenchyma at the time of resection could significantly improve neurosurgical outcomes.

The authors report dural sinus thrombosis diagnosed in 2 patients based on noninvasive imaging results, which were revealed to be dural arteriovenous fistulas (DAVFs) diagnosed using digital subtraction (DS) angiography. The first patient was a 63-year-old man who presented with headaches. Magnetic resonance venography was performed and suggested dural sinus thrombosis of the left transverse sinus and jugular vein. He was administered warfarin anticoagulation therapy but then suffered multiple intracranial hemorrhages. A DS angiogram was requested for a possible dural sinus thrombectomy, but the DS angiogram revealed a DAVF. The patient underwent serial liquid embolization with complete obliteration of the DAVF. The second patient, an 11-year-old boy, also presented with headaches and was diagnosed with dural sinus thrombosis on MR imaging. A DS angiogram was also requested for a possible thrombectomy and revealed a DAVF. This patient underwent serial liquid embolization and eventual operative resection. These reports emphasize that different venous flow abnormalities can appear similar on noninvasive imaging and that proper diagnosis is critical to avoid contraindicated therapies.

OBJECTIVE: Endovascular treatment of intracranial aneurysms is a less invasive alternative than surgical repair. However, the higher risk of recurrence after coiling necessitates regular angiographic surveillance, which has associated risks. To date, the risk of surveillance angiography has not been quantified in patients with intracranial aneurysms treated by endovascular embolization. METHODS: Angiograms performed for the surveillance of coiled intracranial aneurysms in patients treated at 8 institutions were recorded prospectively. Of 3086 patients eligible for surveillance angiography according to each institution's protocol during the study period, 2243 patients (72.7%) underwent this procedure. Data were reviewed retrospectively, including the results of each angiogram, angiographic complications, and morbidity resulting from the procedure. Morbidity was classified as major (modified Rankin Scale score ≥3) or minor (modified Rankin Scale score

OBJECTIVE Intracranial arteriovenous malformations (AVM) may be managed through staged preoperative embolization and resection. Two commonly used liquid embolics are N-butyl cyanoacrylate (nBCA; Cordis Microvascular, Inc., New Brunswick, NJ) and Onyx (ev3, Inc., Irvine, CA). We sought to compare the utility of these agents in terms of fluoroscopy and procedure times. METHODS All intracranial AVMs embolized from 2002 to 2006 at the University of Florida were included in this study. Patients were stratified into three treatment groups: nBCA, Onyx, and patients who received both nBCA and Onyx during separate embolizations. Cohorts were compared by sex, age, Spetzler-Martin grade, AVM volume, fluoroscopy time, procedure time, surgical blood loss, and complications. RESULTS A total of 182 embolizations were performed on 88 patients (nBCA, 60 patients and 106 procedures; Onyx, 20 patients and 43 procedures; and nBCA/Onyx, eight patients and 16 nBCA and 17 Onyx procedures). There were no significant differences in patient demographics, AVM volumes, and Spetzler-Martin grades. Mean fluoroscopy and procedure times were increased for Onyx (57 min; 2.6 h) compared with nBCA (37 min; 2.1 h) embolizations (P < 0.0001 and P = 0.001, respectively). Cumulative mean fluoroscopy time was increased for Onyx (135 min) and nBCA/Onyx (180 min) cohorts relative to nBCA (64 min; P < 0.0001). Cumulative mean procedure time was increased in the nBCA/Onyx group (10.4 h) compared with nBCA (3.7 h) and Onyx (5.4 h; P < 0.0001). Seventy patients (80%) underwent AVM resection. No significant differences in surgical blood loss or complication rates were observed among the cohorts. CONCLUSION Onyx AVM embolization requires increased fluoroscopy and procedure times compared with nBCA. Further investigation is necessary to justify increased radiation exposure and procedure time associated with Onyx.

Background and Purpose— Cerebral vasospasm continues to be a major cause of poor outcome in patients with ruptured aneurysms. Prophylactic Transluminal Balloon Angioplasty (pTBA) appeared to prevent delayed ischemic neurological deficit in a pilot study. A phase II multicenter randomized clinical trial was subsequently designed. Methods— One hundred and seventy patients with Fisher Grade III subarachnoid hemorrhage were enrolled in the study. Of these, 85 patients were randomized to the treatment group and underwent pTBA within 96 hours after subarachnoid hemorrhage. Main end points of the study included the 3-month dichotomized Glasgow Outcome Score (GOS), development of delayed ischemic neurological deficit (DIND), occurrence of Transcranial Doppler (TCD) vasospasm, and length of stay in the ICU and hospital. Results— The incidence of DIND was lower in the pTBA group ( P =0.30) and fewer patients required therapeutic angioplasty to treat DIND ( P =0.03). Overall pTBA resulted in an absolute risk reduction of 5.9% and a relative risk reduction of 10.4% unfavorable outcome ( P =0.54). Good grade patients had absolute and relative risk reductions of respectively 9.5 and 29.4% ( P =0.73). Length of stay in ICU and hospital was similar in both groups. Four patients had a procedure-related vessel perforation, of which three patients died. Conclusions— While the trial is unsuccessful as defined by the primary end point (GOS), proof of concept is confirmed by these results. Fewer patients tend to develop vasospasm after treatment with pTBA and there is a statistically significantly decreased need for therapeutic angioplasty. pTBA does not improve the poor outcome of patients with Fisher grade III subarachnoid hemorrhage.

Objective Angiographic roadmapping, commonly used for catheter navigation in endovascular procedures, is the superimposition of a live fluoroscopic image on a previously stored digitally subtracted angiogram. We evaluated this technique for the first time as a method for image-guided navigation during surgical resection of intracranial and spinal vascular lesions. Methods After obtaining Institutional Review Board approval, we retrospectively reviewed 38 procedures in 35 patients at two centers performed by one neurosurgeon in which intraoperative roadmapping was used as an image-guided navigation tool for surgical resection of cranial and spinal arteriovenous malformations or fistulae. This technique requires femoral or radial artery access and a portable vascular C-arm capable of digitally subtracted angiogram and roadmap angiography in the operating room suite. Once a roadmap identifying the vascular lesion is obtained, a sterile radiopaque instrument is placed over the skin/wound to precisely localize the lesion in multiple dimensions. Results Angiographic roadmapping was used for resection of seven spinal arteriovenous malformations or fistulae, 23 cranial arteriovenous malformations or fistulae, one aneurysm, two carotid-cavernous fistulae, and transtorcular embolization of five vein of Galen malformations. In all cases, the technique helped us to make precisely localized incisions, avoid unnecessary bone removal, and readily directed us to the vascular lesion. In several cases, it allowed localization of small fistulae not visible on magnetic resonance imaging or computed tomographic angiography scans. Finally, this approach facilitated immediate angiographic confirmation of complete resection at the end of each case. Conclusion Angiographic roadmapping is an effective intraoperative navigation tool for resection of vascular lesions that has not been previously described and offers several advantages to frameless stereotaxy.

Background Recently, a great interest has emerged regarding the use of abciximab for treatment of stroke. Thromboembolic events that occur during neuroendovascular procedures represent a unique subset of stroke patients because definitive angiographic diagnosis and treatment can be performed immediately. The existing literature on this situation suggests excellent results; however, most publications are case reports, and the largest series is 13 cases. We report our experience using abciximab in the treatment of acute thromboembolic events that occur during neuroendovascular procedures. Methods We reviewed the last 1373 consecutive patients who underwent neuroendovascular procedures at the University of Florida from our prospectively maintained clinical database. Of these patients, 29 (2.11%) endovascular cases were complicated by acute cerebral thromboembolic events that were treated with abciximab. Abciximab was administered in less than 1 hour after the onset of the occlusion in every patient. The Thrombolysis In Myocardial Infarction (TIMI) scale was used to measure immediate angiographic outcome, and the Modified Rankin Scale (MRS) was used to measure clinical outcome at the time of follow-up. Independent outcome was defined as an MRS of 3 or less at follow-up. Results Angiographic improvement in the TIMI grade was achieved in 29 (81%) of 36 arteries. Three intracerebral hemorrhages occurred with abciximab when administered with concurrent mechanical clot disruption; in two of these hemorrhages, recombinant tissue plasminogen activator (r-tPA) was also administered. The mean follow-up time for the living cohort was 7.54 months. Twenty-four (83%) patients were independent at follow-up, 3 (10%) were dependent at follow-up, and 2 (7%) died. Conclusion Abciximab appears to be safe and effective in the treatment of acute cerebral thromboembolic complications during neuroendovascular procedures.

Objective Proximal posterior inferior cerebellar artery (PICA) aneurysms represent a subset of posterior circulation aneurysms that can be routinely treated with either clipping or coiling. The literature contains limited numbers of patients with proximal PICA aneurysms treated with endovascular surgery. We report our experience with endovascular surgery of proximal PICA aneurysms with emphasis on patients with poor Hunt-Hess grades. Methods We reviewed 31 consecutive patients with proximal PICA aneurysms who were treated with endovascular surgery. The following data were analyzed: age, sex, size of aneurysm, Hunt-Hess grade at presentation, Fisher grade at presentation, angiographic result after embolization, complications, number of days hospitalized, duration of follow-up, angiographic follow-up results, and Glasgow Outcome Score at follow-up. Results Excellent angiographic occlusion was achieved in 30 of 31 (97%) patients. Clinical follow-up with Glasgow Outcome Score was performed on every patient an average of 10 months later. Twenty-one of 31 (68%) patients had good outcomes (Glasgow Outcome Score I or II) at follow-up. Of the patients who presented with a favorable clinical grade (Hunt-Hess 0-III), 13 of 15 (87%) had good outcomes at follow-up. Of the patients who presented with a poor clinical grade (Hunt-Hess Grade IV or higher), 8 of 16 (50%) had good outcomes at follow-up. Conclusion This series demonstrates the safety and efficacy of endovascular surgery for proximal PICA aneurysms. Many patients with poor Hunt-Hess grades from ruptured PICA aneurysms ultimately had a good outcome. This could be secondary to early, aggressive treatment of hydrocephalus and the minimally invasive nature of the endovascular approach.

In this paper, we described a novel fluorescence lifetime-based approach to determine the core–shell nanostructure of FITC-(fluorescein isothiocyanate, isomer I) doped fluorescent silica nanoparticles (FSNPs). Because of phase homogeneity between the core and the shell, electron microscopic technique could not be used to characterize such core–shell nanostructure. Our optical approach not only revealed the core–shell nanostructure of FSNPs but also evaluated photobleaching of FSNPs both in the solvated and non-solvated (dry) states. The FSNPs were produced via Stober's method by hydrolysis and co-condensation reaction of tetraethylorthosilicate (TEOS) and fluorescein linked (3-aminopropyl)triethoxysilane (FITC–APTS conjugate) in the presence of ammonium hydroxide catalyst. To obtain a pure silica surface coating, FSNPs were then post-coated with TEOS. The average particle size was 135 nm as determined by TEM (transmission electron microscope) measurements. Fluorescence excitation and emission spectral data demonstrated successful doping of FITC dye molecules in FSNPs. Fluorescence lifetime data revealed that approximately 62% of dye molecules remained in the solvated silica shell, while 38% of dye molecules remained in the non-solvated (dry) silica core. Photobleaching experiments of FSNPs were conducted both in DI water (solution state) and in air (dry state). Severe photobleaching of FSNPs was observed in air. However, FSNPs were moderately photostable in the solution state. Photostability of FSNPs in both solution and dry states was explained on the basis of fluorescence lifetime data.

Currently available neuroendovascular devices are inadequate for effective treatment of many wide-necked or fusiform intracranial aneurysms and intracranial carotid-cavernous fistulae (CCF). Placing a covered microstent across the intracranial aneurysm neck and CCF rent could restore normal vessel morphology by preventing blood flow into the aneurysm lumen or CCF rent. To fabricate covered microstents, our research group has developed highly flexible ultra thin (approximately 150 microm) silicone coverings and elastomerically captured them onto commercially available metal stents without stitching. Preliminary in vivo studies were conducted by placing these covered microstents in the common carotid artery of rabbits. The feasibility of using covered stents was demonstrated. However, the cover affected the deployment pressure and the stents failed occasionally during deployment due to tearing of the cover. Appropriate modeling of covered stents will assist in designing suitable coverings, and help to reduce the failure rate of covered microstents. The purpose of this study is to use the finite element method to determine the mechanical properties of the covered microstent and investigate the effects of the covering on the mechanical behavior of the covered microstent. Variations in the mechanical properties of the covered microstent such as deployment pressure, elastic recoil and longitudinal shortening due to change in thickness and material properties of the cover have been investigated. This work is also important for custom design of covered microstents such as adding cutout holes to save adjacent perforating arteries.

A 72-year-old woman with a painful left third cranial nerve palsy due to a basilar artery aneurysm situated between the superior cerebellar and posterior cerebral arteries was treated with Guglielmi detachable coils (GDCs). Despite a good initial angiographic result with a small residual neck and improvement in the ocular motility and pain, the patient experienced worsening of the third cranial nerve palsy 15 months later. Cerebral angiography confirmed coil compaction with aneurysmal regrowth. A second endovascular coil embolization resulted in complete obliteration of the aneurysm. The patient experienced complete resolution of the pain and partial resolution of the third cranial nerve palsy. In some patients, a small residual aneurysm neck after endovascular embolization therapy with GDCs can result in delayed aneurysmal regrowth due to coil compaction. Clinical manifestations may herald this dangerous regrowth.

The authors describe a novel approach to the management of high-output heart failure secondary to an intracranial high-flow dural arteriovenous fistula (DAVF) by using extracorporeal membrane oxygenation (ECMO). To the best of the authors' knowledge, this represents the first report of an embolization performed in conjunction with the use of an ECMO circuit and the first report in which an ECMO cannula was used for intraarterial access for cerebral angiography. A 2-day-old girl presented with severe, high-output heart failure secondary to a high-flow intracranial DAVF. The patient was neurologically intact and no brain parenchymal abnormalities were revealed on computerized tomography scanning of the head, but she suffered severe heart failure, pulmonary hypertension, and liver and renal dysfunction. The patient underwent three endovascular embolization procedures involving coils and liquid embolic agents. Despite a decrease in the DAVF flow, the patient had only transient improvement in her pulmonary hypertension, and venoarterial ECMO therapy was instituted. Another embolization was performed while the patient was receiving ECMO therapy. Her cardiovascular status improved, she was weaned from ECMO, and she was eventually discharged home to her family. Extracorporeal membrane oxygenation can be used to sustain severely ill neonates with high-output heart failure secondary to intracranial AVFs. Embolization can be performed while the patient is receiving ECMO therapy.

Background Treatment of internal carotid ruptured blister aneurysms (IC-RBA) presents many challenges to neurosurgeons because of the high propensity for rebleeding during intervention. The role of a Pipeline Embolization Device (PED) in the treatment of this challenging aneurysm subtype remains undefined despite theoretical advantages. Objective To present a series of 11 patients treated with a PED and to discuss the management and results of this novel application of flow diverters. Methods Medical records of patients who presented with IC-RBA from May 2011 to March 2013 were retrospectively reviewed at 6 institutions in the United States. All relevant data were independently compiled. Results A total of 12 IC-RBAs in 11 patients were treated during the study period. Nine (75%) were treated with a single PED; 1 was treated with 2 PEDs; 1 was treated with coils and 1 PED; and 1 was treated with coils and 2 PEDs. Three (27%) had major perioperative complications: middle cerebral artery territory infarction, vision loss, and death. Seven patients demonstrated complete obliteration of the aneurysm in postoperative imaging. Early clinical outcomes were favorable (modified Rankin Scale score, 0-2) in all 10 survivors. Conclusion This study demonstrates the feasibility and safety of using the PED to treat IC-RBA with fair initial results. The proper introduction and management of antiplatelet regimen are key for successful results. Bleeding complications related to dual antiplatelet therapy were similar to those in previous studies of stent-assisted coiling for the same population. Larger cohort analysis is needed to define the precise role of flow diverters in the treatment of IC-RBA.

✓ The authors report the occurrence of ipsilateral transient cavernous sinus syndrome during balloon test occlusion (BTO) of the cervical internal carotid artery (ICA) and discuss the involved pathomechanisms. The authors reviewed their series of 129 BTOs of the ICA performed between 1989 and 1996. Two patients developed facial paresthesias and transient palsies of the third through sixth cranial nerves during test occlusion of the cervical ICA. The tests were performed prior to planned permanent carotid artery occlusion for the treatment of a neck sarcoma in one patient and a giant cavernous carotid artery aneurysm in the other. The patients' symptoms resolved with deflation of the balloon. When the balloon was subsequently inflated above the inferior cavernous sinus artery (ICSA), one of the patients complained of mild facial discomfort. There was no contralateral weakness or mental status change during test occlusion in either patient. Angiography demonstrated good filling of the ipsilateral intracranial circulation via collateral vessels of the circle of Willis. In these two cases, the cranial nerves in the cavernous sinus were likely supplied by the ICA via the meningohypophyseal trunk and the ICSA. In each case, there was excellent blood supply to the ipsilateral cerebral hemisphere; however, there was probably inadequate retrograde filling of the cranial nerve collateral vessels located where the meningohypophyseal trunk and ICSA originated. These cases emphasize the importance of a patent external carotid artery—ICA connection for successful cervical carotid artery occlusion. Neurological examination during BTO was critical to interpret the clinical manifestations caused by the hemodynamic changes.

Objective We present an endovascular technique for treating wide-necked cerebral aneurysms using Guglielmi detachable coils (Target Therapeutics, Fremont, CA) and simultaneous temporary balloon protection. The temporary balloon serves as a mechanical external force to mold the microcoils away from the parent artery. Methods Two illustrative cases of wide-necked cerebral aneurysms treated with Guglielmi detachable coils and a temporary balloon are presented. Emphasis is placed on the technical aspects of the approach, with several variations. The first case involves a left posterior cerebral artery aneurysm at the P1/P2 segment, and the second case involves a left paraclinoid internal carotid artery aneurysm. Both patients suffered from subarachnoid hemorrhage, but neither was a candidate for craniotomy. In each case, the coils, when used alone, protruded into the parent artery and were therefore removed. Then a temporary balloon was inflated for mechanical protection during coil deployment. Results The use of simultaneous temporary balloon protection allowed more dense intra-aneurysmal coil packing, especially in the neck, without parent artery compromise, than did the use of Guglielmi detachable coils alone. Conclusion Endovascular treatment of wide-necked cerebral aneurysms can be facilitated by simultaneous temporary balloon protection.

BACKGROUND Outcomes studies use patient-reported outcome (PRO) measurements to assess treatment effectiveness, but can lack direct clinical meaning. Minimum clinically important difference (MCID) calculation provides a point estimate of the critical threshold needed to achieve clinically relevant treatment effectiveness. MCID remains uninvestigated for microvascular decompression (MVD), a common surgical procedure for trigeminal neuralgia. OBJECTIVE We aimed to determine MCID for the most commonly used PRO measures of pain after MVD: Visual Analog Scale (VAS) and Barrow Neurological Institute Pain Scale (BNI-PS). METHODS Sixty consecutive patients with classic trigeminal neuralgia who decided to undergo MVD by a single surgeon were prospectively assessed with VAS and BNI-PS preoperatively and 2 years postoperatively. Three anchors were used to assign each patient's outcome. We then used 3 well-established, anchor-based methods to calculate MCID. RESULTS Patients experienced significant improvement in both VAS (9.9 vs. 2.0, P < .001) and BNI-PS (5.0 vs. 1.9, P < .001) after MVD. The area under the receiver-operating characteristic curve was greater for BNI-PS than for VAS for all 3 anchors, indicating that BNI-PS is probably better suited for calculating MCID. The 3 MCID calculation methods generated a range of MCID values for each of the PROs (VAS: 1.40-8.87, BNI-PS: 0.95-3.26). CONCLUSION MVD-specific MCID is highly variable based on calculation technique. Some of these calculations appear to either overestimate or underestimate the patients' preoperative expectations. When the different MCID methods are averaged, the results are clinically appropriate and consistent with preoperative expectations. The average MCID for VAS is 6.25 and for BNI-PS is 2.44.

Object. The authors present their experience in performing a transradial approach for neuroendovascular surgery of intracranial vascular lesions when a transfemoral approach was unfavorable. Methods. Eight patients ranging in age from 52 to 88 years underwent a total of nine neuroendovascular procedures for intracranial vascular lesions. A transradial approach was used in all patients. The patients had previously undergone a transfemoral approach for the endovascular intervention, but that procedure was unsuccessful. Five patients had intracranial basilar artery (BA) aneurysms, one patient had symptomatic BA stenosis, one patient had a dural arteriovenous fistula in the posterior fossa, and one patient had a high-flow arteriovenous malformation in the frontal lobe. In each case, a transradial approach achieved a stable platform that allowed intracranial microcatheterization for neuroendovascular intervention. None of the patients experienced complications attributed to the transradial artery approach. Conclusions. During neuroendovascular surgery for the treatment of intracranial lesions, the transradial approach is a viable alternative if the transfemoral approach is unfavorable. This series represents the first known description of neuroendovascular surgery for intracranial lesions via a transradial approach.

Objective The Cerebral Aneurysm Multicenter European Onyx trial was the first multicenter prospective case series using liquid embolization for cerebral aneurysms. It suggested a possible decreased risk for recanalization of smaller aneurysms compared with coil embolization. After publication of that trial, the Onyx HD embolic agent, injection devices, and treatment protocols have all been updated and improved to increase efficacy and decrease adverse events. We present the results from a multicenter registry of liquid embolization treatments using the current method and materials. We hypothesize that the evolution of this technique will result in lower complication and recanalization rates when compared with earlier series. Methods Surgeons performing liquid embolization submitted data about consecutive patients and procedures. The data provided were used to determine what characteristics were associated with durable occlusion and recanalization. Results One hundred thirteen patients at 25 medical centers throughout the United States underwent liquid embolization. Of these, 110 had follow-up data of at least 6 months. Seventeen patients (15%) experienced a complication and 4 (3.5%) experienced procedure-related ischemic stroke or death. Nine patients (8.1%) had aneurysm recanalization and 5 (4.5%) required retreatment. All retreatments were accomplished with further liquid embolization and were stable at the last follow-up angiogram available. Those with durable occlusion had smaller aneurysm size (mean, 10 mm vs. 17 mm) (P = 0.03) and were de novo (P = 0.02). Conclusions Recent advances in liquid embolization have led to decreased recanalization and complications. Liquid embolization is more likely to achieve a durable result in smaller aneurysms that have not been previously treated.

Introduction Embolization of wide-necked intracranial aneurysms can be associated with excessive expense, especially for large/giant aneurysms. Depending on the material used, endovascular treatment may be cost prohibitive. The goal of this study was to evaluate the relative cost of various embolic agents. Methods Utilizing software available at http://www.angiocalc.com, theoretical aneurysm volumes were calculated using aneurysm diameters ranging from 3 to 25 mm increasing in 1 mm increments. For each volume, the software calculated the length of coil needed to fill each size of aneurysm to a consistent, standardized and desirable packing density (25% coil:aneurysm volume). Each theoretical aneurysm was embolized by filling volume in a consistent, standardized, step-wise fashion. The cost of liquid embolics was calculated by adding the cost of 1.5 ml vials of Onyx HD 500 required to fill each volume. The embolic agents were then grouped into seven categories depending on the coil type and the cost of each aneurysm size was averaged. Results The average embolization with small outer diameter (0.010 inches) helical coils ranged between $714 for a 3 mm aneurysm to $113 009 for a 25 mm aneurysm, and between $2855 and $157 245 for small diameter spherical coils. Large outer diameter (>0.010 inches) helical coils cost between $2195 and $34 034 and large diameter spherical coils cost between $2195 and $86 957. Bioactive coils ranged between $1984 and $172 179, liquid embolic $5950 and $35 700, and hydrocoils $1295 and $32 873. Conclusions Larger outer diameter helical coils, hydrocoils and liquid embolics provide a relative cost savings compared with standard, spherical or bioactive coils when aneurysm size, shape, packing density and embolic agent were controlled and standardized. This cost differential increases as the size of the aneurysm increases.

BACKGROUND The mechanisms and management of delayed intracerebral hemorrhage (dICH) after treatment of brain arteriovenous malformations (AVMs) are poorly understood and widely debated. Many clinical predictive factors have been theorized for dICH after an otherwise uneventful AVM embolization, but there is an absence of data to discern their significance. OBJECTIVE To analyze 13 proposed predictive factors and to assess their potential in guiding prevention strategies. METHODS One hundred sixty-eight embolization procedures were performed on 67 patients with brain AVMs by a single surgeon. Patients were divided into 2 groups: those with symptomatic dICH and control subjects. Thirteen factors were analyzed: age, sex, race, previous ICH, Spetzler-Martin grade, AVM size, eloquence, embolic volume, embolic agent, percent obliteration, and timing, number, and stage of embolizations. Univariate and multivariate analyses were performed on these factors to determine significance. RESULTS Six procedures were complicated by dICH; 5 (83%) occurred after the final planned procedure. The volume of embolic agent was significantly higher in the dICH group (4.5 ± 1.0 mL) compared with control subjects (1.7 ± 0.2 mL) in both univariate and multivariate analyses (P < .01), even after controlling for AVM size. AVM size was significant in univariate analysis but not multivariate analysis. There were no statistically significant differences between the groups for any of the other possible predictive factors. CONCLUSION High volume of embolic agent administered per procedure is an independent predictive factor for dICH. Limiting the injected volume for each procedure may reduce this poorly understood complication.

Background Based on numerous reports citing high sensitivity and specificity of non-invasive imaging [e.g. computed tomography angiography (CTA) or magnetic resonance angiography (MRA)] in the detection of intracranial aneurysms, it has become increasingly difficult to justify the role of conventional angiography [digital subtraction angiography (DSA)] for diagnostic purposes. The current literature, however, largely fails to demonstrate the practical application of these technologies within the context of a "real-world" neurosurgical practice. We sought to determine the proportion of patients for whom the additional information gleaned from 3D rotational DSA (3DRA) led to a change in treatment. Methods We analyzed the medical records of the last 361 consecutive patients referred to a neurosurgeon at our institution for evaluation of "possible intracranial aneurysm" or subarachnoid hemorrhage (SAH). Only those who underwent non-invasive vascular imaging within 3 months prior to DSA were included in the study. For asymptomatic patients without a history of SAH, aneurysms less than 5 mm were followed conservatively. Treatment was advocated for patients with unruptured, non-cavernous aneurysms measuring 5 mm or larger and for any non-cavernous aneurysm in the setting of acute SAH. Results For those who underwent CTA or MRA, the treatment plan was changed in 17/90 (18.9%) and 22/73 (30.1%), respectively, based on subsequent information gleaned from DSA. Several reasons exist for the change in the treatment plan, including size and location discrepancies (e.g. cavernous versus supraclinoid), or detection of a benign vascular variant rather than a true aneurysm. Conclusions In a "real-world" analysis of intracranial aneurysms, DSA continues to play an important role in determining the optimal management strategy.

Postprocedural rebleeding is a significant source of morbidity following endovascular treatment of ruptured intracranial aneurysms. Previous large-scale reports include the Cerebral Aneurysm Rerupture After Treatment trial, the International Subarachnoid Aneurysm Trial, and the study on Early Rebleeding after Coiling of Ruptured Cerebral Aneurysms, which reported nonprocedural rebleeding rates within 30 days of treatment of 2.7%, 1.9%, and 1.4%, respectively. However, coiling of intracranial aneurysms is in a state of continual change due to advancing device design and evolving techniques. These studies included only patients initially treated prior to 2004. In the present study the authors assess the most recent short-term results with endovascular treatment of ruptured aneurysms.A multicenter retrospective chart review was conducted of patients undergoing endovascular treatment for ruptured intracranial aneurysms between July 2004 and October 2009. The technique used, including the use of stent or balloon assistance, was evaluated. Demographic and clinical factors, such as sex, age, initial clinical presentation, aneurysm size, aneurysm location, and modified Raymond Classification following initial treatment, were also evaluated and compared between the groups in which rebleeding did and did not occur.A total of 469 patients underwent endovascular treatment for a ruptured aneurysm; nonprocedural rehemorrhage occurred within 30 days of the initial coiling in 4 cases (0.9%). Two patients (50%) died after rehemorrhage. Stent-assisted coiling was used during the original treatment in 1 (25%) of the 4 patients with a rerupture. However, no technical, clinical, or demographic factors were found to be statistically significant in association with rebleeding.Recent data suggest that the periprocedural rebleeding rate may be improving over time.

Previous investigators have supported the idea that glucocorticoids may be oncolytic. In this study, the percentage of cell death in two human glioblastoma cell cultures was related to the concentration of dexamethasone that was administered. It was determined that for Cell line 1, the median lethal dose was approximately 500-800 micrograms/ml and the completely lethal dose was about 900-1000 micrograms/ml; the 3H-thymidine uptake to approximate the mitotic rate was 16,607 cpm, and the dexamethasone receptor activity was 228 fmol/mg protein. The median lethal dose and completely lethal dose for Cell line 2 was approximately 500-600 micrograms/ml and 700-1000 micrograms/ml, respectively; the 3H-thymidine uptake was 8402 cpm, and the dexamethasone receptor activity was 137 fmol/mg protein. These lethal concentrations of dexamethasone are probably higher than can be tolerated by systemic delivery. However, it remains to be seen whether the interstitial administration of dexamethasone could achieve local concentrations resulting in the oncolysis of malignant gliomas. The clinical significance of these findings will depend on the local tolerance of normal brain parenchyma to very high doses of dexamethasone. A review of some of the literature is included.

Serum angiotensin converting enzyme (ACE) levels are higher in patients with diabetes mellitus than in many others. Techniques are available to grade different degrees of diabetic retinopathy, which can demonstrate a relationship between ACE and diabetic retinopathy. In this study, patients with diabetic retinopathy had higher serum ACE levels (6.3 +/- 0.2) than nondiabetic patients (4.3 +/- 0.5) (p0.001). In addition, the mean serum ACE level in diabetic patients with nonproliferative retinopathy (5.55 +/- 0.4) was less than that in diabetic patients with proliferative retinopathy (6.63 +/- 0.25) (p = 0.02). Due to the variability in individual serum ACE levels and the frequent use of ACE inhibitors by hypertensive diabetics, these techniques are not suitable for retinopathy screening programs. However, the graded relationship demonstrated by these data may have relevance for the pathophysiology of diabetic retinopathy.

The authors report the 8-year follow-up of a patient previously described in the literature who originally presented in high-output cardiac failure secondary to a complex neonatal intracranial dural arteriovenous fistula (DAVF). The earlier case report described palliative treatment with a combination of extracorporeal membrane oxygenation (ECMO) and endovascular embolization for life-threatening high-output cardiac failure secondary to a DAVF. Access was obtained using the ECMO cannula, and embolization was performed while the patient was connected to the ECMO machine. The patient made an excellent recovery following partial embolization of the fistula, but then presented again 7 years later with worsening headaches secondary to significant growth of the known residual portion of the fistula identified on CT angiography. The child also developed bilateral femoral artery (FA) occlusions secondary to multiple previous FA punctures. To achieve complete obliteration of the remaining fistula, the patient required a retroperitoneal approach to the iliac artery and percutaneous puncture of the internal jugular vein. Embolization was performed with a combination of platinum coils and ethylene vinyl alcohol copolymer liquid embolic agent. There were no complications, and the child remains neurologically normal, with no signs of permanent cardiovascular sequelae. In this case report, the authors discuss the long-term management of AVFs treated by endovascular strategies early in life. After neonatal access, sometimes the FAs occlude, requiring more invasive access strategies. The authors also discuss the follow-up method, intervals, and threshold for further treatment for these lesions, and present a review of the literature.

Background Onyx HD 500 (eV3, Irvine, CA) is a high-viscosity liquid embolic agent that has recently been approved in the United States as a humanitarian use device for the treatment of wide-neck sidewall intracranial aneurysms. Preliminary evidence suggest that liquid embolic agents can provide improved angiographic results with a lower incidence of recanalization compared to coil embolization. Objective To report unstable Onyx casts and how to deal with them. Methods We report 4 cases of intracranial aneurysms treated with Onyx HD 500 in which, after the aneurysm was successfully obliterated, the Onyx cast was noted to have 1 of 2 types of embolic cast instability. In all 4 cases, an intracranial stent or vascular reconstruction device (VRD) was placed across the Onyx cast at the aneurysm orifice and the cast was stabilized. Conclusion This series is the first published description of Onyx HD 500 aneurysm cast instability. It is also the first report of using a stent or vascular reconstruction device rescue technique to secure an unstable Onyx cast and represents a new indication for these devices.

OBJECTIVE Quantifying vasospasm has traditionally been performed manually, a method prone to imprecision and user bias. An alternative approach is to use computerized image analysis techniques to define and quantify the diameter of a vessel. The goal of this article is to demonstrate a novel automated vessel measurement algorithm specific to the needs of vasospasm studies and to compare it with traditional manual measurements in an animal model of vasospasm. METHODS A total of 576 arterial diameter measurements were collected by 4 independent, blinded examiners from 24 angiograms in a rabbit subarachnoid hemorrhage (SAH) model. Measurements were taken from 3 segments of the basilar artery in anteroposterior and lateral projections, both before SAH and after SAH-induced vasospasm. Means and standard deviations of 288 manual measurements were compared with 288 automated measurements. RESULTS The precision of automated measurements was significantly improved compared with standardized manual measurements (85.7% decrease in variation; P < .001). When using automated measurements, the precision was not affected by vessel size, but when using manual measurements, smaller arteries were less precise (P = .04). There was no significant difference in precision between 2 different contrast concentrations (P = .32). CONCLUSION Automated measurements of basilar artery diameters are more precise than manual measurements, both before and after SAH-induced vasospasm. The variability in the manual group worsens when the artery is smaller secondary to vasospasm, indicating a need for the use of this segmentation method.

BACKGROUND: Trigeminal neuralgia (TN) is a syndrome with debilitating paroxysmal facial pain, one cause of which is thought to be vascular compression of the nerve root entry zone causing ephaptic transmission. Arteriovenous malformations (AVM) have been reported to cause TN, including AVMs in the cerebellopontine (CP) angle. These lesions have been successfully treated with endovascular coiling, ethylene-vinyl alcohol copolymer (Onyx) and surgery for decompression. CASE DESCRIPTION: We present a case of TN caused by AVM in the CP angle in a patient who was not a candidate for microsurgery and who did not want radiofrequency treatment or other destructive procedures because he would not tolerate facial numbness. The patient's symptoms were successfully treated by embolization using an ethylene-vinyl alcohol copolymer. After 17 months he had a recurrence of pain which was again treated with palliative embolization and again experienced resolution of his symptoms. CONCLUSION: This case demonstrates that palliative embolization is a safe and effective option for the treatment of trigeminal neuralgia pain in patients for whom surgery of the AVM is not an option.

The acquisition of bony fusion is a complex task. Attention paid to the details presented here may improve fusion rates and patient outcomes. We have much to learn. We should focus on the details of the present and on the possibilities of the future to guide our surgical decision-making process. Indeed, "traumatized bone, whether disrupted via an overt act of trauma or via surgical intervention, heals best when bone healing enhancing parameters are optimized." Our problem to date is that we do not precisely know when, and under what loading conditions, such an optimization process occurs. It is certain that pressure and load affect this process, as suggested by Wolff. This has been portrayed here. The measurement of these parameters in vivo in humans should provide insight into the process of bone healing and ultimately lead to our ability to positively affect the healing of bone and, hence, patient outcomes.

Brain mapping aims to localize neurological function to specific regions of the human brain. Preoperative endovascular brain mapping (PEBM) is a novel approach that allows clear visualization of nonfunctional (silent) brain parenchyma in real time during a resection. It has potential to improve neurosurgical guidance because brain shift does not alter the maps, and the map is visualized directly on the brain in situ rather than on a nearby image. Therefore, the risk of a new neurological deficit should be reduced. The authors report the first PEBM approach that combines selective molecular targeting of brain endothelium with multispectral (optical) imaging in preclinical animal models.Sprague-Dawley rats and New Zealand white rabbits were selectively catheterized, and a fluorescein isothiocyanate-derivatized tomato lectin-based imaging probe was administered into the carotid artery or posterior cerebral artery, measuring500 microm in diameter. After binding/uptake of the imaging probe, and removal of unbound probe, a craniotomy was performed to directly visualize the "brain map."Selective localization of the imaging probe to the right hemisphere in rats or right posterior cerebral artery in rabbits was clearly visualized after craniotomy. Cross-sections of stained capillaries demonstrated that the imaging probe did not cause vascular occlusion. Gross regional selectivity of the imaging probe was documented by multispectral molecular imaging of intact brains, with discrete localization and endothelium-directed targeting validated by histological examination.The authors have demonstrated the first molecular endothelium-targeted approach to PEBM that does not require manipulation of the intact blood-brain barrier or result in vascular occlusion. Furthermore, the presented multispectral molecular imaging technique appears to be a suitable methodology for the generation of region-selective brain maps of vascularized brain parenchyma. Further refinement of the PEBM approach, as well as the development of improved imaging probes, may result in clinical advancement of PEBM where direct visual discrimination of nonfunctional silent brain parenchyma at the time of resection could significantly improve neurosurgical outcomes.

The aim of this study was to determine the anatomical limitations of the transcallosal transchoroidal approach to the third ventricle.Twenty-six formalin-fixed specimens were studied. Sagittal dissections were used to determine the anatomical relationships of the foramen of Monro, the angle of approach to landmarks, and placement of a callosotomy. Lateral ventricular dissections were performed to quantitate the forniceal anatomy.The foramen of Monro was found 1.07+/-0.11 cm superior and slightly anterior to the mammillary bodies, 1.48+/-0.16 cm posterosuperior to the optic recess, and 2.26+/-0.16 cm anterosuperior to the aqueduct. Relative to the genu, a callosal incision 2.64+/-0.53 cm long and angled 37+/-4.3 degrees anterior was needed to access the aqueduct, and an incision 4.92+/-0.71 cm long and angled 49+/-7.4 degrees posterior was needed to access the optic recess. The fornix progressively widened within the lateral ventricle, from 1.25+/-0.63 mm at the foramen of Monro to7 mm at 2 cm behind the foramen. Three zones of exposure were identified, requiring unique craniotomies, callosotomies, and angles of approach. The major limiting factors in the approach included the columns of the fornix anteriorly, the width of the fornix posteriorly, and the draining veins of the parietal cortex. The choroidal fissure opening was limited to 1.5 cm posterior to the foramen of Monro; this limited opening created an aperture effect that required an anterior-to-posterior angle, an anterior craniotomy, and an anteriorly placed callosotomy to access the posterior landmarks. In contrast, a posterior-to-anterior angle, posteriorly placed craniotomy, and posteriorly placed callosotomy were required to access anterior landmarks.The transcallosal transchoroidal approach was ideally suited to access the foramen of Monro and the middle and posterior thirds of the third ventricle. Exposure of the anterior third ventricle was limited by the columns of the fornix and by the presence of parietal cortical draining veins.

The authors report dural sinus thrombosis diagnosed in 2 patients based on noninvasive imaging results, which were revealed to be dural arteriovenous fistulas (DAVFs) diagnosed using digital subtraction (DS) angiography. The first patient was a 63-year-old man who presented with headaches. Magnetic resonance venography was performed and suggested dural sinus thrombosis of the left transverse sinus and jugular vein. He was administered warfarin anticoagulation therapy but then suffered multiple intracranial hemorrhages. A DS angiogram was requested for a possible dural sinus thrombectomy, but the DS angiogram revealed a DAVF. The patient underwent serial liquid embolization with complete obliteration of the DAVF. The second patient, an 11-year-old boy, also presented with headaches and was diagnosed with dural sinus thrombosis on MR imaging. A DS angiogram was also requested for a possible thrombectomy and revealed a DAVF. This patient underwent serial liquid embolization and eventual operative resection. These reports emphasize that different venous flow abnormalities can appear similar on noninvasive imaging and that proper diagnosis is critical to avoid contraindicated therapies.

Intracranial arteriovenous malformations (AVM) may be managed through staged preoperative embolization and resection. Two commonly used liquid embolics are N-butyl cyanoacrylate (nBCA; Cordis Microvascular, Inc., New Brunswick, NJ) and Onyx (ev3, Inc., Irvine, CA). We sought to compare the utility of these agents in terms of fluoroscopy and procedure times.All intracranial AVMs embolized from 2002 to 2006 at the University of Florida were included in this study. Patients were stratified into three treatment groups: nBCA, Onyx, and patients who received both nBCA and Onyx during separate embolizations. Cohorts were compared by sex, age, Spetzler-Martin grade, AVM volume, fluoroscopy time, procedure time, surgical blood loss, and complications.A total of 182 embolizations were performed on 88 patients (nBCA, 60 patients and 106 procedures; Onyx, 20 patients and 43 procedures; and nBCA/Onyx, eight patients and 16 nBCA and 17 Onyx procedures). There were no significant differences in patient demographics, AVM volumes, and Spetzler-Martin grades. Mean fluoroscopy and procedure times were increased for Onyx (57 min; 2.6 h) compared with nBCA (37 min; 2.1 h) embolizations (P0.0001 and P = 0.001, respectively). Cumulative mean fluoroscopy time was increased for Onyx (135 min) and nBCA/Onyx (180 min) cohorts relative to nBCA (64 min; P0.0001). Cumulative mean procedure time was increased in the nBCA/Onyx group (10.4 h) compared with nBCA (3.7 h) and Onyx (5.4 h; P0.0001). Seventy patients (80%) underwent AVM resection. No significant differences in surgical blood loss or complication rates were observed among the cohorts.Onyx AVM embolization requires increased fluoroscopy and procedure times compared with nBCA. Further investigation is necessary to justify increased radiation exposure and procedure time associated with Onyx.

Objective To determine the prevalence of early branch aneurysms, characterize these lesions angiographically and anatomically, and determine their clinical significance. Methods The authors conducted a retrospective review of 125 consecutive patients with a diagnosis of middle cerebral artery (MCA) aneurysm. Eighty-four patients harboring 100 MCA aneurysms were studied; 41 patients were excluded for lack of adequate imaging or for fusiform morphology of the aneurysm. Demographic characteristics including age, side, sex, subarachnoid hemorrhage, intracerebral hematoma, multiple aneurysms, and type of treatment were obtained. Results The average patient age was 57.3 years (range, 29-79 yr); 69 were women and 15 were men. Fifty-eight were right MCA aneurysms and 42 were left aneurysms. Fourteen patients had multiple MCA aneurysms. Thirty-nine of 100 aneurysms were associated with subarachnoid hemorrhage. Twelve of 100 aneurysms were associated with an intracerebral hematoma. The average aneurysm sizes were 9.1 mm overall (range, 2.0-27.0 mm), 12.3 mm for ruptured aneurysms, and 7.5 mm for unruptured. There were 36 M1 bifurcation aneurysms, 39 early frontal branch aneurysms, 18 early temporal branch aneurysms, four lenticulostriate artery aneurysms, and three trifurcation aneurysms. Conclusion In our retrospective review, the majority of MCA aneurysms arose along the M1 segment proximal to the M1 bifurcation. Early frontal branch aneurysms were more common than typical M1 segment bifurcation aneurysms. M1 segment aneurysms arising from early frontal and early temporal branches have distinct anatomic features that impact surgical management and outcome. Understanding the relationship between the recurrent lenticulostriate arteries arising from the proximal segments of these early branches and the aneurysm neck should allow surgeons to avoid many postoperative ischemic complications when dealing with these challenging lesions.