Multicenter registry of liquid embolic treatment of cerebral aneurysms.

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.

Percutaneous stereotactic radiofrequency lesioning for trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient-reported outcomes.

BACKGROUND: The Visual Analog Scale (VAS) and the Barrow Neurological Institute Pain Scale (BNI-PS) are 2 patient-reported outcome (PRO) tools frequently used to rate pain from trigeminal neuralgia (TN). Outcomes studies often use these patient-reported outcomes to assess treatment effectiveness, but it is unknown exactly what degree of change in the numerical scores constitutes the minimum clinically important difference (MCID). MCID remains uninvestigated for percutaneous stereotactic radiofrequency lesioning (RFL), a common surgical procedure for TN. OBJECTIVE: To determine MCID values for the VAS and BNI-PS in patients undergoing RFL. METHODS: Forty-three consecutive patients with TN who underwent RFL by a single surgeon were prospectively assessed with the VAS and BNI-PS preoperatively and 3 years postoperatively. Three anchors were used to assign each patient's outcome: satisfaction, willingness to have the surgery again, and Health Transition Index. We then used 3 well-established, anchor-based methods to calculate MCID: average change, minimum detectable change, and change difference. RESULTS: Patients experienced substantial improvement in both VAS (9.81 vs 3.35; P < .001) and BNI-PS (4.95 vs 2.44; P < .001) after RFL. The 3 MCID calculation methods generated a range of MCID values for each of the PROs (VAS, 4.13-8.20; BNI-PS, 1.03-3.30). The area under the receiver-operating characteristic curve was greater for BNI-PS compared with VAS for all 3 anchors, indicating that BNI-PS is probably better suited for calculating MCID. CONCLUSION: RFL-specific MCID is variable on the basis of the calculation technique. With the use of the minimum detectable change calculation method with the Health Transition Index anchor, the minimum clinically important difference is 4.49 for VAS and 1.16 for BNI-PS after RFL for TN. ABBREVIATIONS: AUC, area under the receiver-operating characteristic curveBNI-PS, Barrow Neurological Institute Pain ScaleHTI, Health Transition IndexMCID, minimum clinically important differenceMDC, minimum detectable changePRO, patient-reported outcomeRFL, percutaneous stereotactic radiofrequency lesioningTN, trigeminal neuralgiaVAS, Visual Analog Scale.

Foramen ovale puncture, lesioning accuracy, and avoiding complications: microsurgical anatomy study with clinical implications.

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.

Microvascular decompression for classic trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient reported outcomes.

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.

Biomechanical attributes of microcatheters used in liquid embolization of intracranial aneurysms.

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.

Delayed intracerebral hemorrhage after uneventful embolization of brain arteriovenous malformations is related to volume of embolic agent administered: multivariate analysis of 13 predictive factors.

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.

"Real-world" comparison of non-invasive imaging to conventional catheter angiography in the diagnosis of cerebral aneurysms.

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.

The spectrum of management practices in nontraumatic subarachnoid hemorrhage: A survey of high-volume centers in the United States.

BACKGROUND: There is a considerable variety of management practices for nontraumatic subarachnoid hemorrhage (ntSAH) across high-volume centers in the United States. We sought to design a survey which would highlight areas of controversy in the modern management of ntSAH and identify specific areas of interest fo further study. METHODS: A questionnaire on management practices in ntSAH was formulated using a popular web-based survey tool (SurveyMonkey(™), Palo Alto, CA) and sent to endovascular neurointerventionists and cerebrovascular surgeons who manage a high volume of these patients annually. Two-hundred questionnaires were delivered electronically, and after a period of 2 months, the questionnaire was resent to nonresponders. RESULTS: Seventy-three physicians responded, representing a cross-section of academic and other high-volume centers of excellence from around the country. On average, the responding interventionists in this survey each manage approximately 100 patients with ntSAH annually. Over 57% reported using steroids to treat this patient population. Approximately 18% of the respondents use intrathecal thrombolytics in ntSAH. Over 90% of responding physicians administer nimodipine to all patients with ntSAH. Over 40% selectively administer antiepileptic drugs to patients with ntSAH. Several additional questions were posed regarding the methods of detecting and treating vasospasm, as well as the indications for CSF diversion in patients with ntSAH further demonstrating the great diversity in management. CONCLUSION: This survey illustrates the astonishing variety of treatment practices for patients with ntSAH and underscores the need for further study.

Both surgical clipping and endovascular embolization of unruptured intracranial aneurysms are associated with long-term improvement in self-reported quantitative headache scores.

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.

Rebleeding risk after treatment of ruptured intracranial aneurysms.

OBJECT: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Recent data suggest that the periprocedural rebleeding rate may be improving over time.

Eight-year follow-up after palliative embolization of a neonatal intracranial dural arteriovenous fistula with high-output heart failure: management strategies for symptomatic fistula growth and bilateral femoral occlusions in pediatric patients.

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.

Endovascular treatment of side wall aneurysms using a liquid embolic agent: a US single-center prospective trial.

OBJECTIVE: Onyx HD-500 is a liquid embolic agent consisting of ethylene vinyl alcohol copolymer dissolved in dimethylsulfoxide and mixed with tantalum. This viscous embolic agent was designed to treat intracranial side wall aneurysms, but there have been no prospective published series from the United States. From this early experience, we developed several protocol revisions, technical details, and clinical pearls that have not been published for liquid embolic embolization of aneurysms. CLINICAL PRESENTATION: We present our single-center prospective series of patients treated with Onyx HD-500 from a multicenter, randomized, controlled trial. Thirteen patients received Onyx HD-500, and their ages ranged from 43 to 81 years. Twelve patients had aneurysms on the internal carotid artery, and 1 patient had an aneurysm the vertebral artery. Every patient had an immediate postangiographic result with 90% or more occlusion by an independent core laboratory assessment. In 1 patient, the Onyx HD-500 injection was aborted, and the aneurysm was embolized with coils. Eleven of 13 patients (85%) underwent 6-month follow-up angiography that demonstrated persistent durable occlusion with no recanalization. There was 1 complication (8%) and no deaths. CONCLUSION: This is the only prospective series of intracranial aneurysms treated with Onyx HD-500 in the United States. This is also the first publication that describes detailed procedure techniques, recommended protocol revisions, lessons learned from early complications, clinical pearls, and advantages and disadvantages of liquid embolic embolization of aneurysms.

Use of intracranial stenting to secure unstable liquid embolic casts in wide-neck sidewall intracranial aneurysms.

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.

Relative cost comparison of embolic materials used for treatment of wide-necked intracranial aneurysms.

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.

Complete angiographic obliteration of intracranial AVMs with endovascular embolization: incomplete embolic nidal opacification is associated with AVM recurrence.

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.

Ultrahigh-dose intraarterial infusion of verapamil through an indwelling microcatheter for medically refractory severe vasospasm: initial experience. Clinical article.

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.

An automated algorithm to improve the precision of basilar artery diameter measurements before and after subarachnoid hemorrhage-induced vasospasm in an animal model.

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.

Embolization of a giant pediatric, posttraumatic, skull base internal carotid artery aneurysm with a liquid embolic agent.

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 x 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.

Defining the risk of retreatment for aneurysm recurrence or residual after initial treatment by endovascular coiling: a multicenter study.

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) or permanent (>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.