Geographic Differences in Endovascular Treatment and Retreatment of Cerebral Aneurysms

BACKGROUND AND PURPOSE

Comparing outcomes between endovascular aneurysm coiling trials can be difficult because of heterogeneity in patients and end points. We sought to understand the impact of geography on aneurysm retreatment in patients enrolled in the Matrix and Platinum Science Trial.

MATERIALS AND METHODS

Post hoc analysis was performed on data from the Matrix and Platinum Science trial. Patients were stratified as either North American or international. Baseline patient demographics, comorbidities, aneurysm characteristics, procedural complications, and clinical and angiographic outcomes were compared.

RESULTS

We evaluated 407 patients from 28 North American sites and 219 patients from 15 international sites. Patient demographics differed significantly between North American and international sites. Aneurysms were well occluded postprocedure more often at international than North American sites (P < .001). Stents were used significantly more often at North American sites (32.7% [133 of 407]) compared with international sites (10.0% [22 of 219]; P < .001). At 455 days, there was no difference in the proportion of patients alive and free of disability (P = .56) or with residual aneurysm filling (P = .10). Ruptured aneurysms were significantly more likely to have been retreated at North American sites within the first year (P < .001) and at 2 years (P < .001). Among all patients for whom the treating physician believed there to be Raymond 3 aneurysm filling at follow-up, absolute rates of retreatment at international and North American sites were similar by 2-year follow-up.

CONCLUSIONS

Data from the Matrix and Platinum Science Trial demonstrate that aneurysm retreatment occurs with different frequency and at different times in different regions of the world. This trend has critical value when interpreting trials reporting short-term outcomes, especially when judgment-based metrics such as retreatment are primary end points that may or may not take place within the defined study follow-up period. Though these variations can be controlled for and balanced within a given randomized trial, such differences in practice patterns must be accounted for in any attempt to compare outcomes between different trials. Despite these differences, endovascular-treated intracranial aneurysms around the world have similar clinical outcomes.

Intraprocedural aneurysmal rupture during coil embolization of brain aneurysms: role of balloon-assisted coiling

BACKGROUND AND PURPOSE

Intraprocedural aneurysmal rupture is a feared complication of coil embolization of intracranial aneurysms and is associated with high rates of morbidity and mortality. We report the incidence, endovascular management, and clinical outcome of patients with IAR, with emphasis on the role of the balloon-assisted technique.

MATERIALS AND METHODS

We conducted a retrospective analysis of all intracranial aneurysms treated by coil embolization between September 2001 and June 2011. All patients with IAR were studied. Comparison of immediate clinical outcomes was performed by using univariate analysis (Fisher exact test).

RESULTS

Of 652 intracranial aneurysms treated with coil embolization, an IAR occurred in 22 (3.4%). Rupture occurred during placement of coils in 18 cases, microcatheters in 2 cases, and a guidewire in 1 case, and during induction of anesthesia in 1 case. Before treatment, 15 of 22 (68%) patients were in good clinical condition (WFNS grade I). There were fewer patients with worsening of the WFNS grade following an IAR when the balloon-assisted technique was used (7.7%) compared with when it was not (55.5%) (P = .023). Death occurred in 2 (9.1%) patients.

CONCLUSIONS

IAR is a potentially serious complication of coil embolization. If IAR occurs, balloon-assistance is helpful in obtaining rapid hemostasis resulting in better short-term outcomes.

Intra-arterial chemotherapy as a treatment for intraocular retinoblastoma: alternatives to direct ophthalmic artery catheterization

BACKGROUND AND PURPOSE

Intra-arterial chemotherapy is a very effective treatment option for intraocular retinoblastoma. However, direct catheterization of the OA is not always possible. The purpose of this work was to report our initial results with intra-arterial chemotherapy for intraocular retinoblastoma when delivery of the drug was not via direct catheterization of the OA.

MATERIALS AND METHODS

Retrospective review of 110 eyes (89 patients) undergoing a total of 351 intra-arterial treatments at our institution between 2006 and 2010 identified 18 eyes (14 patients) that received at least 1 infusion via a vascular route other than direct OA catheterization. Alternatives included catheterization of the orbital branch of the MMA and temporary balloon occlusion of the ICA.

RESULTS

Tumor control was observed in 17 of 18 eyes at a mean follow-up of 18.9 months (median, 17.5 months; range, 8-36 months). The mean number of intra-arterial infusions was 3.7 per eye (median, 3; range, 2-9). Treatment routes included the following: MMA only, 3 eyes; MMA + OA, 4 eyes; MMA + balloon, 2 eyes; balloon only, 1 eye; balloon + OA, 7 eyes; balloon + OA + MMA, 1 eye. Intra-arterial chemotherapies included melphalan, topotecan, and carboplatin. Complications were all transient. ERG readings were the following: stable, 10 eyes; improved, 3 eyes; reduced, 5 eyes. One patient died from a second malignancy (pinealoblastoma).

CONCLUSIONS

This initial experience shows that when direct OA catheterization is not possible, using alternative routes of intra-arterial chemotherapy saves eyes and preserves vision with acceptable side effects.

Endovascular treatment of spinal arteriovenous lesions: beyond the dural fistula

During the past few decades, there have been significant advances in the understanding of spinal vascular lesions, mainly because of the evolution of imaging technology and selective spinal angiography techniques. In this article, we discuss the classification, pathophysiology, and clinical manifestations of spinal vascular lesions other than DAVFs and provide a review of the endovascular approach to treat these lesions.

Secondary clinical deterioration after successful embolization of a spinal dural arteriovenous fistula: a plea for prophylactic anticoagulation

We present a case of delayed aggravation of initially-resolved symptoms in a patient after successful embolization of a T5 spinal dural arteriovenous (AV) fistula with N-butyl cyanoacrylate. The symptoms were attributed to venous thrombosis and resolved with systemic anticoagulation after five days of treatment. Although the most adequate treatment for preventing venous thrombosis after spinal dural AV fistula is not known, we describe this patient as a case for more aggressive prophylactic anticoagulation measures in the immediate post-embolization time period.

Intra-procedural aneurysm rupture treated with n-butyl cyanoacrylate embolization: technical note

A case is described of utilizing liquid polymer and stent placement to treat a procedural rupture of intracranial aneurysm during coil embolization. Although this technique is challenging, it seals the rupture immediately and can be used when additional coil placement is not possible.

Balloon-assisted superselective intra-arterial cerebral infusion of bevacizumab for malignant brainstem glioma. A technical note

Malignant brainstem gliomas (BSG) are rare tumors in adults, associated with a grim prognosis and limited treatment options. Currently, radiotherapy represents the mainstay of treatment, although new studies suggest an increased role for certain chemotherapeutic agents. Intravenous (IV) administration of bevacizumab (Avastin, Genentech Pharmaceuticals) has been shown to be active in the treatment of some enhancing malignant brainstem gliomas. The IV route of administration, however, carries a risk of systemic side effects such as bowel perforation, wound disrepair and pulmonary embolism. In addition, the percentage of IV drug that reaches the tumor site is restricted by the blood brain barrier (BBB).Weill Cornell Brain Tumor Center, Department of Neurosurgery, Weill Cornell Medical College of Cornell University: New York, NY, USA. This technical report describes our protocol in performing superselective intra-arterial cerebral infusion (SIACI) of bevacizumab using endovascular balloon-assistance in the top of the basilar artery in a patient with a recurrent malignant brainstem glioma. It represents the first time such a technique has been performed for this disease. This method of drug delivery may have important implications in the treatment of both adult and pediatric brainstem gliomas.

Early endovascular management of oculomotor nerve palsy associated with posterior communicating artery aneurysms

Palsy of the third cranial nerve (oculomotor nerve, CNIII) is a well-known clinical presentation of posterior communicating artery (P-com) aneurysm. We report a series of 11 patients with partial or complete third nerve palsy secondary to P-com aneurysm. All were treated with endovascular embolization within seven days of symptom onset. Third nerve palsy symptoms resolved in 7/11 (64%), improved in 2/11 (18%) and did not change in 2/11 (18%) patients.

Balloon-assisted technique for trapped microcatheter retrieval following onyx embolization. A case report

SUMMARY

During embolization of a large frontal arteriovenous malformation (AVM), Onyx-18 (eV3) was injected into an M3 branch of the middle cerebral artery via a Marathon microcatheter (eV3). After 40 minutes of embolization, the microcatheter could not be retracted due to fixation within the Onyx cast despite prolonged, robust attempts. A balloon microcatheter (Hyperform(TM), eV3) was advanced distally and inflated to provide distal counter tension, allowing microcatheter retrieval with minimal traction on the vasculature.

Endovascular treatment of carotid blowout syndrome: who and how to treat

Carotid blowout syndrome (CBS) is a high-risk condition associated with significant morbidity and mortality that may result from invasion and destruction of the cervical carotid vasculature from head and neck squamous cell carcinoma. Endovascular approaches offer multiple modalities for treatment to prevent morbidity and death. In this paper we review our experience in addressing CBS and present an up-to-date algorithm of endovascular management. 16 lesions were identified in 8 patients treated with 9 procedures over the past year. Pseudoaneurysm and/or active extravasation were documented in at least one vessel in all 8 cases presenting with acute CBS. There were 13 pseudoaneurysms in external carotid artery (ECA) trunk (5), ECA branches (4), internal carotid artery (ICA) (1) and common carotid artery (CCA) (3). There were 3 additional ICA lesions due to tumor infiltration, resulting in ICA occlusion (2) and long segment stenosis (1). Permanent vessel occlusion was performed in 11 lesions of the ECA trunk (4), ECA branches (4) and ICA (3). Stent-grafts were placed in 5 lesions in the CCA (3), ICA (1) and ECA trunk (1). Technical success and immediate hemostasis were achieved in all patients. There were no procedural deaths or immediate complications. With a median follow-up of 2 months (range, 1-13 months), three patients died: one from recurrent CBS, one from global brain ischemia after a cardiac arrest event unrelated to CBS and one from systemic disease. There was no other recurrence of bleeding or neurological complication. Endovascular techniques offer an armamentarium to effectively address CBS, significantly affecting the care and outcome in this particular oncologic population. These techniques should be offered as early as possible in the context of a multidisciplinary approach.

Novel microcatheters for selective intra-arterial injection of fluid in the rat brain

BACKGROUND AND PURPOSE

The internal carotid artery (ICA) in the rat has a single extracranial branch, which supplies the muscles of mastication. The rat ICA also has multiple intracranial branches including (from proximal to distal): multiple small perforating arteries which supply the hypothalamus and the anterior choroidal artery which supplies the choroid plexus and part of the basal ganglia. At the ICA terminus, the vessel bifurcates into the anterior and middle cerebral arteries. The purpose of this study was to demonstrate selective injection of ICA branches in the rat.

MATERIALS AND METHODS

Microcatheters (mucath1 and mucath2) were fabricated by plugging the tip of 169-mum outer diameter polyimide tubing and perforating the sidewalls. A 450-mum polydimethyl-siloxane cylinder was affixed to the distal tip of mucath2 but not mucath1. We evaluated the territory of mucath1 injection ex vivo using magnetization-prepared rapid acquisition of gradient echo MR imaging of brain specimens injected at necropsy. Territories of mucath1 and mucath2 injection were evaluated in vivo with dynamic susceptibility-weighted contrast-enhanced MR imaging. The territory of mucath2 also was evaluated in vivo with fused static microPET/T1 MR images performed after [(18)F] fluorodeoxyglucose ((18)FDG) injection. We evaluated additional catheterized and injected animals at 48 hours using physical examination, T2 MR images, and postmortem brain histologic specimens.

RESULTS

Gadolinium-diethylene-triamine pentaacetic acid (Gd-DTPA) and (18)FDG injected through mucath1 selectively opacified the ipsilateral cerebral hemisphere, with no contralateral opacification. Gd-DTPA injected through mucath2 selectively opacified the territories of the hypothalamic perforating arteries, and anterior choroidal artery. There was no iatrogenic complication 48 hours after 20- to 25-minute injections performed with mucath1 or mucath2.

CONCLUSIONS

We have developed 2 microcatheters which can be placed in the ICA for selective injection of its branches. One microcatheter selectively injects the ipsilateral cerebral hemisphere. The other selectively injects only the hypothalamus and lateral thalamus.

Predictors and timing of hypotension and bradycardia after carotid artery stenting

BACKGROUND AND PURPOSE

Hypotension and bradycardia are common in carotid artery stenting (CAS) and are particularly worrisome in the high risk patient who is typically referred for CAS. The purpose of this work was to assess the incidence and predictors of hypotension and bradycardia and the risk of their delayed occurrence after CAS.

MATERIALS AND METHODS

A total of 53 men and 40 women (median age, 71 years) with symptomatic (57%) or asymptomatic (42%) carotid artery stenosis had CAS performed in our institution between December 2002 and January 2007. Patient vital sign records for the 12 hours post-CAS were analyzed. The relative decrease of blood pressure and pulse rate were used as primary end points, and the requirement of pressor or anticholinergic drugs was used as a surrogate end point. Significant predictors of hypotension and bradycardia were analyzed with a logistic regression model. Cumulative freedom from hypotension and bradycardia was calculated by using the Kaplan-Meier method. Negative predictive value (NPV) of screening for early hypotension and bradycardia was determined.

RESULTS

The incidence of hypotension, bradycardia, and both was 14%, 23%, and 15%, respectively. Drug intervention was required in 45 patients (48%). Asymptomatic stenosis was an independent predictor of hypotension and bradycardia. Stenosis proximity to the bifurcation and dilation percentage were independent predictors of the drug intervention requirement. Seven patients (8%) had new onset of hypotension or bradycardia later than 6 hours post-CAS. The NPV of early hypotension and bradycardia was 97% and 93%, respectively.

CONCLUSION

In this retrospective study, the risk of hypotension or bradycardia after CAS is significantly influenced by the degree of dilation performed, and the risk of their delayed occurrence may justify a minimum of 12 hours postprocedural vital sign monitoring.

Thrombolytic therapy of acute ischemic stroke during pregnancy

The authors report eight pregnant women with acute ischemic stroke treated with thrombolysis (rt-PA [recombinant human tissue plasminogen activator] or urokinase). Seven women recovered. Two extracranial and two asymptomatic intracranial hemorrhages complicated treatment; one woman died of arterial dissection complicating angiography. Three patients had therapeutic abortions, two fetuses were miscarried, and two babies were delivered healthy. Although pregnant women may be treated safely with thrombolytics, risks and benefits to mother and fetus must be carefully weighed.

The New York Islands AVM Study: design, study progress, and initial results

BACKGROUND AND PURPOSE

Prospective population-based data on the incidence of brain arteriovenous malformation (AVM) hemorrhage are scarce. We studied lifetime detection rates of brain AVM and incident AVM hemorrhage in a defined population.

METHODS

The New York islands (ie, Manhattan Island, Staten Island, and Long Island) comprise a 9,429,541 population according to the 2000 census. Since March 15, 2000, all major New York islands hospitals have prospectively reported data on consecutive patients living in the study area with a diagnosis of brain AVM and whether the patient had suffered AVM hemorrhage. Patients living outside the ZIP code-defined study area were excluded from the study population.

RESULTS

As of June 14, 2002, 284 prospective AVM patients (mean+/-SD age, 35+/-18 years; 49% women) were encountered during 21,216,467 person-years of observation, leading to an average annual AVM detection rate of 1.34 per 100,000 person-years (95% CI, 1.18 to 1.49). The incidence of first-ever AVM hemorrhage (n=108; mean age, 31+/-19 years; 45% women) was 0.51 per 100,000 person-years (95% CI, 0.41 to 0.61). The estimated prevalence of AVM hemorrhage among detected cases (n=144; mean age, 33+/-19 years; 50% women) was 0.68 per 100,000 (95% CI, 0.57 to 0.79).

CONCLUSIONS

Our prospective data, spanning 27 months, suggest stable rates for AVM detection and incident AVM hemorrhage. Approximately half of AVM patients may suffer intracranial hemorrhage.

Diffusion-perfusion MRI characterization of post-recanalization hyperperfusion in humans

BACKGROUND

Animal and human studies have demonstrated that postischemic hyperperfusion may occur both early and late timepoints following acute cerebral ischemia.

OBJECTIVE

To use diffusion-perfusion MRI to characterize hyperperfusion in humans following intra-arterial thrombolysis.

METHODS

MRI were performed before treatment, several hours following vessel recanalization, and at day 7 in patients successfully recanalized with intra-arterial thrombolytics.

RESULTS

Hyperperfusion was visualized in 5 of 12 patients within several hours after recanalization (mean volume, 18 mL; range, 7 to 40 mL), and in 6 of 11 patients at day 7 (mean volume, 28 mL; range, 4 to 45 mL). Within the core region of hyperperfusion, mean cerebral blood flow was 2.1 times greater than in the contralateral homologous region at the early time point, and 3.1 times greater at day 7. Seventy-nine percent of voxels with hyperperfusion at day 7 demonstrated infarction at day 7, whereas only 36% of voxels (within the initial hypoperfusion region) not showing hyperperfusion at day 7 demonstrated infarction at day 7. Mean pretreatment apparent diffusion coefficient (ADC) and perfusion values were more impaired in voxels that subsequently developed hyperperfusion compared with other at-risk voxels (all p values < 0.0001). There were no significant differences in the degree of clinical improvement in patients with regions of hyperperfusion versus those without, although sample size limited power to detect group differences.

CONCLUSIONS

Postischemic hyperperfusion, visualized with perfusion MRI in humans following recanalization by intra-arterial thrombolytic therapy, occurred in about 40% of patients within hours and in about 50% of patients at day 7. Hyperperfusion developed mainly in regions that went on to infarction. Compared with other abnormal regions, tissues that developed postischemic hyperperfusion had greater bioenergetic compromise in pretreatment apparent diffusion coefficient values and greater impairment in pretreatment blood flow measures.

Grading and surgical planning for intracranial arteriovenous malformations

The treatment of arteriovenous malformations (AVMs) has evolved over the last 40 years. These complex vascular lesions remain among the most difficult lesions to treat. Successful treatment of AVMs of the brain includes extensive preoperative planning, multimodality treatment options, and modern postoperative surgical care. The advent of new technologies, including interventional neuroradiology and radiosurgery, has expanded the range of malformations that can be treated effectively and has had a significant impact on those individuals who manifest this disease process. The purpose of this paper is to describe the current grading technique used by the authors and to explore the preoperative treatment and planning that leads to successful surgical obliteration of these lesions. Some description of preoperative interventions, including radiosurgery and interventional procedures will be mentioned; however, only in the context of how they impact on the surgical treatment of these lesions. In other articles in this edition of Neurosurgical Focus interventional procedures and radiosurgery as treatment adjuncts and as primary therapies will be discussed in greater detail.

Head and neck hypervascular lesions: embolization with ethylene vinyl alcohol copolymer--laboratory evaluation in Swine and clinical evaluation in humans

PURPOSE

(a) To assess in swine long-term (12-month) histopathologic changes, particularly, those related to recanalization and angiotoxicity after endovascular delivery of ethylene vinyl alcohol copolymer (EVAC), and (b) to evaluate initial clinical experience in 18 patients with head and neck tumors and arteriovenous malformations.

MATERIALS AND METHODS

Embolization with EVAC was performed in one rete each in five swine. After 12 months, an angiogram was obtained, and the contralateral rete was also embolized (acute). Swine were sacrificed and the retia harvested for pathologic examination. In the clinical study, 18 patients with tumors (n = 14), facial arteriovenous malformations (n = 3), and vertebral arteriovenous fistula (n = 1) underwent therapeutic embolization. The technical aspects of EVAC embolization, percentage of occlusion, and clinical complications were evaluated.

RESULTS

Angiographic 12-month follow-up in swine revealed persistent occlusion of the embolized rete or retia. Histologic examination of the same rete showed vascular occlusion and moderate intraluminal foreign body giant cell reaction; the acutely embolized rete showed no endothelial denudation or angionecrosis. Clinical evaluation in patients revealed satisfactory penetration of lesion vasculature with EVAC when the microcatheter was advanced within 2 cm of a lesion or when percutaneous puncture was performed. There were two transient complications: one increase in a preexisting fifth nerve palsy and one increase in preexisting hemiparesis.

CONCLUSION

EVAC is a promising liquid embolic material providing long-term occlusion of blood vessels.

Endovascular treatment of basilar artery trunk aneurysms with Guglielmi detachable coils: clinical experience with 41 aneurysms in 39 patients

OBJECT

The authors present a retrospective analysis of their clinical experience in the endovascular treatment of basilar artery (BA) trunk aneurysms with Guglielmi detachable coils (GDCs).

METHODS

Between April 1990 and June 1999,41 BA trunk aneurysms were treated in 39 patients by inserting GDCs. Twenty-seven patients presented with subarachnoid hemorrhage, six had intracranial mass effect, and in six patients the aneurysms were found incidentally. Eighteen lesions were BA trunk aneurysms, 13 were BA-superior cerebellar artery aneurysms, four were BA-anterior inferior cerebellar artery aneurysms, and six were vertebrobasilar junction aneurysms. Thirty-five patients (89.7%) had excellent or good clinical outcomes; procedural morbidity and mortality rates were 2.6% each. Thirty-six aneurysms were selectively occluded while preserving the parent artery, and in five cases the parent artery was occluded along with the aneurysm. Immediate angiographic studies revealed complete or nearly complete occlusion in 35 aneurysms (85.4%). Follow-up angiograms were obtained in 29 patients with 31 aneurysms: the mean follow-up period was 17 months. No recanalization was observed in the eight completely occluded aneurysms. In 19 lesions with small neck remnants, seven (36.8%) had further thrombosis, three (15.8%) remained anatomically unchanged, and nine (47.3%) had recanalization caused by coil compaction. In one patient (2.6%) the aneurysm rebled 8 years after the initial embolization.

CONCLUSIONS

In this clinical series the authors show that the GDC placement procedure is valuable in the therapeutic management of BA trunk aneurysms. The endovascular catheterization of these lesions tends to be relatively simple, in contrast with more complex neurosurgical approaches. Endosaccular obliteration of these aneurysms also decreases the possibility of unwanted occlusion of perforating arteries to the brainstem.

Dural arteriovenous fistula in children: endovascular treatment and outcomes in seven cases

BACKGROUND AND PURPOSE

Dural AVF is a vascular anomaly that rarely occurs in children and is best treated by endovascular embolization. We report our experience using various endovascular embolization techniques in the treatment of dural AVF in a pediatric population.

METHODS

Seven children with angiographically proven dural AVF were treated with endovascular embolization using microcoils, N-butylcyanoacrylate, detachable balloons, and/or silk suture. All imaging studies, embolization procedures, and patient charts were retrospectively reviewed.

RESULTS

Seven children had been treated for dural AVF at our institution since 1987. Three newborns presented with congestive heart failure. Four older children (10 months-10 years) presented with signs referable to venous hypertension, including seizures, hydrocephalus, and proptosis. Embolization approaches included transarterial, transvenous, and direct puncture after neurosurgical exposure of a dural sinus. The number of embolizations ranged from 1 to 13 sessions per patient. All patients experienced symptomatic improvement after each embolization session. The three newborns showed marked improvement in cardiac function that allowed discharge to home. Clinical follow-up ranged from 3 weeks to 9 years (mean, 4.1 years). Two children with partially embolized dural AVF died, and one was lost to follow-up. Four children are alive after complete embolization of their dural AVF; two are developmentally normal, and two have mild developmental delay.

CONCLUSION

Endovascular embolotherapy is the current treatment of choice for dural AVF. Embolization therapy may be life saving in the setting of cardiac failure and curative in cases of small or simple fistulae. Multiple, complex dural AVF are usually not curable, and treatment is aimed at symptomatic relief. Treatment strategies focus on the location and/or complexity of the fistula, the patient's clinical status, and the neurologic prognosis.

Pitfalls of GDC Embolisation of Intracranial Aneurysms

SUMMARY

We present a critical analysis of the cerebral aneurysm GDC embolisation technique and its numerous possible pitfalls with the experience of 448 aneurysms in 401 patients performed during a seven year period at UCLA's Division of Interventional Neuroradiology. A "pitfall" is defined as any hidden or not easily recognized danger or difficulty. We review pitfalls related to micro-catheterization, GDC coil delivery, complex vascular anatomy, post-embolisation management, and pre-existing patient's clinical condition. The possible associated technical and clinical complications include aneurysm rupture, parent artery occlusion, thrombo-embolic stroke, coil stretching/rupture, coil migration, incomplete embolisation or embolisation failure. Lastly we present a discussion of our experience and suggestions of how to avoid some of these pitfalls.

Embolization of arteriovenous malformations with Onyx: clinicopathological experience in 23 patients

OBJECTIVE

To report our experience in treatment of arteriovenous malformations (AVMs) using a new liquid embolic agent, Onyx (Micro Therapeutics, Inc., Irvine, CA).

METHODS

Between January 1998 and May 1999, 23 patients (8 men and 15 women) were treated. The patients' average age was 40 years, with seizure being the most common presenting symptom (39%). The average Spetzler-Martin grade on presentation was 3. The average AVM volume before embolization was 14.5 cm3.

RESULTS

We observed an average 63% reduction in AVM volume after 129 arterial feeders were embolized. There were four adverse events. Two patients experienced ischemia because of inadvertent occlusion of an arterial feeder. One of these patients made a full recovery, but the other patient had a permanent deficit. Two other patients experienced transient neurological deficits that resolved within 1 week of embolization. Permanent morbidity was thus 4% (1 of 23 patients). There were no deaths. Twelve patients underwent subsequent radiosurgery, and 11 patients had surgery that resulted in complete resection of their AVMs. Histopathological examinations showed mild acute inflammation in specimens resected 1 day after embolization. Chronic inflammatory changes were observed in specimens resected more than 4 days after embolization. In two patients, angionecrosis of the embolized vessels was noted. No evidence of parenchymal hemorrhage was observed in these patients, and vessel wall integrity was maintained as well.

CONCLUSION

Onyx is a new nonadhesive liquid embolic agent that has been used to treat 23 patients at our institution with good results. Its nonadhesive nature and ease of use make it a promising agent in the future treatment of AVMs.

Surgical and endovascular treatment of spinal dural arteriovenous fistulas: long-term disability assessment and prognostic factors

OBJECT

The authors assessed clinical outcomes of patients with treated spinal dural arteriovenous fistulas (DAVFs) and investigated prognostic factors.

METHODS

Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; seven underwent surgery after failed embolization: and 16 underwent embolization alone. The outcomes of gait and micturition disability, were analyzed. Follow up averaged 3.4 years (range 1 month-11.8 years). Age, duration of symptoms, pre- and postintervention magnetic resonance (MR) imaging findings, and preintervention disability were correlated with outcome. Seventeen patients (57%) experienced improved gait, 12 (40%) were unchanged, and one (3%) was worse. In 11 patients (37%) micturition function was improved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait disability, as measured by the Aminoff-Logue Scale, was significantly improved after treatment, from 3.4+/-1.4 (average +/- standard deviation) to 2.7+/-1.5 (p = 0.007). Mean micturition disability scores decreased, but not significantly, from 1.9+/-1 to 1.6+/-1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients with Aminoff-Logue Scale Grade 4 disability (eight of nine improved; p = 0.024). For patients treated within 13 months of symptom onset, mean micturition disability decreased (p = 0.035). No association was found between clinical improvement and age, a symptom duration less than 30 months, or pre- and postintervention MR imaging-documented spinal cord edema.

CONCLUSIONS

Spinal DAVF treatment significantly improved patients' mean gait disability score by almost one grade at last follow up. The mean micturition disability score was not significantly improved, unless treatment was performed within 13 months of symptom onset. Longer and more uniform follow-up study is needed to determine if improved and stabilized clinical outcomes are sustained.

Intraarterial chemotherapy for brain tumors by using a spatial dose fractionation algorithm and pulsatile delivery

PURPOSE

To evaluate the cause of complications in intraarterial chemotherapy for brain tumors and validate a dosage algorithm based on arterial territory.

MATERIALS AND METHODS

Four hundred sixty-two procedures were performed in 113 patients. Technique included pulsatile infusion of a chemotherapeutic agent. Dosage was calculated per hemisphere and divided per arterial territory according to a spatial dose fractionation algorithm based on the vascular territories of major cerebral arteries: middle cerebral artery, 60%; anterior cerebral artery, 20%; posterior cerebral artery, 15%; and perforator arteries, 5%. Hospital charts of all patients were retrospectively reviewed for complications, with specific attention given to the angiograms to determine a cause. Then, subgroup analysis of the chemotherapy protocol with the largest patient population was performed to evaluate predictors of complications.

RESULTS

Six (1.3%) complications were asymptomatic; 12 (2.6%), transient neurologic; three (0.6%), permanent minor neurologic; three (0.6%), permanent major neurologic; and 32 (7.0%), seizures. In the subgroup analysis, the hemispheric dose administered according to the algorithm was strongly predictive of seizure and neurologic deficit.

CONCLUSION

Neurotoxicity of intraarterial cerebral chemotherapy can be minimized by using pulsatile injection and the described spatial dose fractionation algorithm.

N-butyl 2-cyanoacrylate embolization of spinal dural arteriovenous fistulae

BACKGROUND AND PURPOSE

Because they are not well established, we investigated the technical success and recurrence rates of n-butyl 2-cyanoacrylate (NBCA) embolization of spinal dural arteriovenous fistulae (SDAVF), and assessed clinical outcomes.

METHODS

We retrospectively studied all patients with SDAVF treated by NBCA embolization at our institution over an 8-year period. Gait and micturition disabilities were analyzed. Follow-up periods averaged 3.1 years (range, 1 month to 8.9 years).

RESULTS

NBCA embolization was feasible in 74% (20/27) of patients. Of 20 patients who underwent embolization, initial embolization failure occurred in two (10%) and fistula occurrence in three (15%). All five patients in whom NBCA embolization failed underwent surgery. All patients who underwent embolization had either improved (55%) or unchanged (45%) gait disability at last follow-up. Seventeen (85%) patients had improved (40%) or unchanged (45%) micturition disability, but three (15%) had worsened. Mean Aminoff gait disability grade significantly decreased at last follow-up (2.4 [1.4] average [SD] vs 3.2 [1.4] [P = .0008]). Mean micturition disability grade decreased, but not significantly (1.4 [1.0] vs 1.7 [1.1] [P = .28]).

CONCLUSION

NBCA embolization of SDAVF was technically feasible in 75% of patients. Initial apparent successful embolization was achieved in 90%; the fistula recurrence rate (failure to occlude the draining vein) for NBCA was 15%. Comparing favorably to surgical series, NBCA embolization of SDAVF appears efficacious, significantly improving mean gait disability by almost one grade at last follow-up. Close clinical and angiographic surveillance is mandatory. Longer and more uniform follow-up is needed to determine if clinical improvement and stabilization after NBCA embolization are sustained.

Endovascular treatment of basilar tip aneurysms using Guglielmi detachable coils: anatomic and clinical outcomes in 73 patients from a single institution

OBJECTIVE

Seventy-three consecutive patients with 75 basilar tip aneurysms were treated with Guglielmi detachable coil (GDC) technology. Their anatomic and clinical outcomes are discussed.

METHODS

Seventy-five basilar tip aneurysms were treated with the GDC system at the University of California, Los Angeles Medical Center from 1990 to 1999. The average age of the population was 48.3 years (range, 28-82 yr). Forty-two patients (57.5%) presented with acute subarachnoid hemorrhage, 8 patients (10.9%) had unruptured aneurysms with mass effect, and 23 patients (31.5%) had incidental aneurysms. Thirty-one aneurysms (41.3%) were small with a small neck, 18 (24%) were small with a wide neck, 16 (21.3%) were large, and 10 (13.3%) were giant aneurysms.

RESULTS

Immediate anatomic outcomes demonstrated complete or near-complete occlusion in 64 aneurysms (85.3%) and incomplete occlusion in 7 aneurysms (9.3%). Four aneurysms (5.3%) could not be embolized because of anatomic difficulties. Of the 69 patients treated with GDCs, 63 patients (91.3%) remained neurologically intact or unchanged from their initial clinical status. Procedure-related morbidity and mortality were 4.1% and 1.4%, respectively. Long-term follow-up angiograms were obtained in 41 patients with 42 aneurysms. Thirty aneurysms (71.4%) demonstrated complete or near-complete occlusion. One incompletely embolized giant aneurysm ruptured during the follow-up period.

CONCLUSION

In contrast to surgical clipping of basilar tip aneurysms, the main technical challenge of the Guglielmi detachable coiling procedure depends on the shape of the aneurysm, not its location. The results of this study indicate that endovascular GDC technology is an appropriate therapeutic alternative in ruptured or unruptured basilar tip aneurysms regardless of patient age, clinical presentation, clinical status, or timing of treatment.

Natural history of the neck remnant of a cerebral aneurysm treated with the Guglielmi detachable coil system

OBJECT

The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms is still unknown. The purpose of this study was to evaluate the anatomical evolution of neck remnants in aneurysms treated with GDCs.

METHODS

Of 455 aneurysms treated with GDCs from 1990 to 1998 at the University of California at Los Angeles Medical Center, 178 aneurysms (39%) had residual necks postembolization. Long-term follow-up angiograms were obtained in 73 of these aneurysms in 71 patients. The mean duration of angiographic follow up was 17.3 months. Twenty-four of the aneurysms were small with small necks, 24 were small with wide necks, 15 were large, and 10 were giant aneurysms. In small aneurysms with small necks, postembolization angiography revealed 12 aneurysms (50%) with progressive thrombosis, eight (33%) unchanged, and four (17%) with recanalization. In small aneurysms with wide necks, six (25%) had progressive thrombosis, eight (33%) remained unchanged, and 10 (42%) had recanalization. In large aneurysms, two (13%) were unchanged and 13 (87%) had recanalization. Of the giant aneurysms only one (10%) remained unchanged and nine (90%) had recanalization. Overall, 18 aneurysms (25%) exhibited progressive thrombosis, 19 (26%) remained unchanged, and 36 (49%) displayed recanalization on follow-up angiography. During the last 2 years of the study, the recanalization rate decreased and a higher rate of progressive thrombosis was noted in aneurysms with small necks. These positive changes are related to important new technical developments.

CONCLUSIONS

Treatment with GDCs appears to be effective and the results permanent in most small aneurysms with small necks. However, there are important technical limitations in the current GDC technology that prevent recanalization in wide-necked or large or giant aneurysms.

Volume-rendered helical computerized tomography angiography in the detection and characterization of intracranial aneurysms

OBJECT

The goal of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography in patients with intracranial aneurysms. The authors compared the abilities of CT angiography, digital subtraction (DS) angiography, and three-dimensional time-of-flight magnetic resonance (MR) angiography to characterize aneurysms.

METHODS

Helical CT angiography was performed in 45 patients with suspected intracranial aneurysms by using volume-rendered multiplanar reformatted (MPR) images. Digital subtraction angiography was performed using biplane angiography. These studies and those performed using MR angiography were interpreted in a blinded manner. Two neurosurgeons and two interventional neuroradiologists independently graded the utility of CT angiography with respect to aneurysm characterization. Fifty-five aneurysms were detected. Of these, 48 were evaluated for treatment. Computerized tomography angiography was judged to be superior to both DS and MR angiography in the evaluation of the arterial branching pattern at the aneurysm neck (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.007), aneurysm neck geometry (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.001), arterial branch incorporation (compared with DS angiography, p = 0.021, and with MR angiography, p = 0.001), mural thrombus (compared with DS angiography, p < 0.001), and mural calcification (compared with DS angiography, p < 0.001, and with MR angiography, p < 0.001). For surgical cases, CT angiography had a significant impact on treatment path (p = 0.001), operative approach (p = 0.001), and preoperative clip selection (p < 0.001). For endovascular cases, CT angiography had an impact on treatment path (p < 0.02), DS angiography study time (p = 0.01), contrast agent usage (p = 0.01), and coil selection (p = 0.02). Computerized tomography angiography provided unique information about 39 (81%) of 48 aneurysms, especially when compared with DS angiography (p = 0.003). The sensitivity and specificity of CT angiography compared with DS angiography was 1. The sensitivity and specificity of CT and DS angiography studies compared with operative findings were 0.98 and 1, respectively.

CONCLUSIONS

Computerized tomography angiography is equal to DS angiography in the detection and superior to DS angiography and MR angiography in the characterization of brain aneurysms. Information contained in volume-rendered CT angiography images had a significant impact on case management.

Endovascular treatment of dural sinus thrombosis with rheolytic thrombectomy and intra-arterial thrombolysis

BACKGROUND AND PURPOSE

Cerebral venous thrombosis is a rare entity that can be difficult to manage. Intrasinus thrombolysis is an increasingly applied intervention, but this modality carries an increased risk of hemorrhage. We describe for the first time an option with a potentially lower incidence of intracranial bleeding, the combination of the AngioJet rheolytic thrombectomy catheter with intra-arterial thrombolysis, in 2 patients with extensive dural sinus thromboses, preexisting intracranial hemorrhage, and severe progressive neurological deficits despite heparin therapy.

METHODS

Four procedures were performed in 2 patients with thromboses in the superior sagittal and transverse sinuses (right in 1 patient and bilateral in 1 patient) and cortical veins. Rheolytic thrombectomy was performed in the sigmoid, transverse, straight, and superior sagittal sinuses; this technique involves the use of the Bernoulli effect to create a vacuum that fragments and aspirates thrombus. For associated persistent cortical vein thromboses, low-dose intra-arterial thrombolysis was used.

RESULTS

Both patients had excellent angiographic results with sinus reopening after rheolytic thrombectomy and cortical vein reopening after intra-arterial thrombolysis. Follow-up CT showed no change in 1 patient and increased preexisting intracranial hemorrhage in the other. One patient had a negative hypercoagulable workup, and the other patient had probable anti-phospholipid antibody syndrome. At 6 months, both patients had excellent clinical outcome with no neurological deficits except mild short-term memory loss in 1 patient.

CONCLUSIONS

The combination of rheolytic thrombectomy with intra-arterial thrombolysis is a treatment modality that allows accelerated recanalization of occluded dural sinuses and cerebral veins with lower doses of thrombolytic agents.

Thrombolytic reversal of acute human cerebral ischemic injury shown by diffusion/perfusion magnetic resonance imaging

Diffusion magnetic resonance imaging provides an early marker of acute cerebral ischemic injury. Thrombolytic reversal of diffusion abnormalities has not previously been demonstrated in humans. Serial diffusion and perfusion imaging studies were acquired in patients experiencing acute hemispheric cerebral ischemia treated with intra-arterial thrombolytic therapy within 6 hours of symptom onset. Seven patients met inclusion criteria of prethrombolysis and postthrombolysis magnetic resonance studies, presence of large artery anterior circulation occlusion at angiography, and achievement of vessel recanalization. Mean diffusion-weighted imaging lesion volume at baseline was 23 cm3 (95% confidence interval [95% CI], 8-38 cm3) and decreased to 10 cm3 (95% CI, 3-17 cm3) 2.5 to 9.5 hours after thrombolysis. Mean apparent diffusion coefficient lesion volume decreased from 9 cm3 (95% CI, 2-16 cm3) at baseline to 1 cm3 (95% CI, 0.4-2 cm3) early after thrombolysis. A secondary increase in diffusion volumes was seen in 3 of 6 patients at day 7. In all 4 patients in whom perfusion imaging was obtained before and after treatment, complete resolution of the perfusion deficit was shown. Diffusion magnetic resonance signatures of early tissue ischemic injury can be reversed in humans by prompt thrombolytic vessel recanalization. The ischemic penumbra includes not only the region of diffusion/perfusion mismatch, but also portions of the region of initial diffusion abnormality.

Prognostic factors in recurrent glioblastoma multiforme and anaplastic astrocytoma treated with selective intra-arterial chemotherapy

BACKGROUND AND PURPOSE

Factors predictive of primary brain tumor outcome have been studied extensively, although the prognostic value of radiologic data, such as MR imaging and angiographic characteristics, has not been studied in depth. The purpose of this study was to determine whether radiologic data were prognostic factors among patients with recurrent glioblastoma multiforme and anaplastic astrocytoma treated with selective intra-arterial chemotherapy.

METHODS

Forty-six patients were enrolled in a Phase II study of intra-arterial chemotherapy with carboplatin and Cereport (Alkermes Inc.; Cambridge, MA), a bradykinin analog that selectively increases permeability of the blood-tumor barrier. MR imaging volumes of enhancing tumor, resection cavity, and T2 signal abnormality were measured with T1-weighted and T2-weighted sequences. Volumes were analyzed individually and in various combinations. Tumor vascularity was graded on angiograms. Outcome was measured by time to tumor progression and survival.

RESULTS

Of 46 patients included in this study, 41 underwent evaluation. Thirty were male and 11 were female; mean age was 48.5 years. Karnofsky scores ranged from 70 to 100. Thirty-two patients had glioblastoma multiforme, whereas nine had anaplastic astrocytoma. Twenty-eight patients had tumor progression and 13 had stable disease. Twenty-three patients died after an average of 205 days; 18 were surviving at an average of 324 days from the start of intra-arterial chemotherapy. In multivariate analysis, time from diagnosis to intra-arterial chemotherapy was predictive both of time to tumor progression and survival. Net tumor volume and vascularity also were significant for survival. Age, Karnofsky performance status, histologic findings, gender, MR imaging area, resection cavity volume, T2 signal abnormality volume, and various combined volumes were not significant.

CONCLUSION

If confirmed by further studies, radiologic factors such as tumor volume and angiographic vascularity should be considered in design and stratification of future chemotherapy trials.

Embolization with radiopaque microbeads of polyacrylonitrile hydrogel: evaluation in swine

PURPOSE

To perform in vitro and in vivo studies of radiopaque microbeads of polyacrylonitrile (PAN) hydrogel to evaluate their characteristics as embolic material.

MATERIALS AND METHODS

PAN microbeads were analyzed in vitro for swelling in different concentrations of contrast material and saline solution and injected through various microcatheters. In three nonsurvival swine, various organs were embolized with PAN microbeads. In eight survival swine, the rete mirabile was embolized with PAN microbeads or polyvinyl alcohol particles. Follow-up angiograms were obtained regularly, and histopathologic analysis was performed at 1 and 6 months.

RESULTS

The microbeads were black with a regular shape and smooth surface. They were easily visible in the syringe and easy to inject through the microcatheters. When wet, their diameters increased by 40%. The microbeads were sufficiently radiopaque to be visible in all vascular territories. Vascular occlusion was not permanent, and even when embolization was adequate, some revascularization was detected at 3 months. The microbeads were intact and still radiopaque at 6 months. Histopathologic examination demonstrated variable inflammatory reactions and foreign-body giant cell reaction and no angionecrosis or hemorrhage.

CONCLUSION

Because PAN microbeads are biocompatible, radiopaque, and easy to handle during embolization procedures, they have potential as a therapeutic embolic agent.

Development of biologically active GDC for the treatment of cerebral aneurysms

In Vitro Study: The surface of polystyrene dishes were treated either by: 1) collagen coating without ion implantation, or 2) collagen coating with ion implantation. Ne(+) implantation was performed on area 2 with fluences of 1 x 10(15) at an energy of 150 keV Bovine endothelial cells were cultured on the dishes and the resistance to detachment of cells was evalated with trypsin treatment. Experimental Aneurysm Study: GDCs were coated with either type I collagen, fibronectin, vitronectin, laminin or fibrinogen. Ion implantation was then performed on these protein-coated GDCs. 56 experimental aneurysms were constructed microsurgically in the bilateral common carotid arteries of 28 swine. The aneurysms were embolized with standard GDCs or with ion-implanted protein-coated GDCs. The animals were sacrificed at day 14 after coil placement. The aneurysmal orifice was observed microscopically. In vitro study showed that endothelial cell proliferation and strength of cell attachment were accerelated by ion implantation. On specimens examined 14 days post-embolization, greater fibrous tissue coverage at the neck of the aneurysm was observed macroscopically and microscopically with ion implanted GDCs, whereas only a fibrin-like thin layer covered the standard GDC surfaces. These in vitro and in vivo studied indicate that ion implantation combined with protein coating of GDCs improves cellular adhesion/proliferation. This technology may provide an improvement in clinical outcome of cerebral aneurysms.

Development of the biologically active Guglielmi detachable coil for the treatment of cerebral aneurysms. Part II: an experimental study in a swine aneurysm model

BACKGROUND AND PURPOSE

Ion implantation is a surface-modification technology that creates a borderless surface on protein-coated platinum; this change in physical and chemical properties on the surface of Guglielmi detachable coils (GDCs) appears to enhance cell proliferation and adhesion. Our purpose was to evaluate the effect of ion implantation on GDCs in an experimental aneurysm model.

METHODS

GDCs were coated with either type I collagen, fibronectin, vitronectin, laminin, or fibrinogen. Using He+ or Ne+ 1 x 10(14-15) ions/cm2, ion implantation was performed on these protein-coated GDCs (GDC-Is). A total of 56 experimental aneurysms were constructed microsurgically in the common carotid arteries of 28 swine. These experimental aneurysms were embolized with standard GDCs (n = 23), collagen GDC-Is (n = 11), vitronectin GDC-Is (n = 6), laminin GDC-Is (n = 4), fibrinogen GDC-Is (n = 6), and fibronectin GDC-Is (n = 6). The animals were sacrificed at day 14 after coil embolization. The physical properties of the new coils (friction on delivery, deployment into aneurysms, trackability, etc) and the development of tissue scarring and neoendothelium across the aneurysm's orifice were evaluated macroscopically and microscopically.

RESULTS

No evidence of increased coil friction/stiffness was observed during delivery of GDC-Is through microcatheters in this aneurysm model. A more intense scar formation and neoendothelium at the neck of aneurysms were observed macroscopically when treated with GDC-Is. Significant differences in the proportion of neck coverage between standard GDCs (48.3% +/- 20.5%) and all GDC-I groups were observed (collagen GDC-I-89.4% +/- 14.9%, P < .01; vitronectin GDC-I-71.5% +/- 7.0%, P < .05; laminin GDC-I-76.5% +/- 11.0%, P < .05; fibrinogen GDC-I-74.8% +/- 13.9%, P < .05; fibronectin GDC-I-87.5% +/- 15.0%, P < .01). Light microscopy showed a well-organized fibrous tissue bridging the aneurysm's neck when using GDC-Is, whereas only a fibrin-like thin layer covered the standard GDC surfaces.

CONCLUSION

GDC-Is indicated a more intense inflammatory response in the aneurysm body and dome and faster re-endothelial coverage of the neck of the aneurysm. This accelerated histologic response may decrease the chances of coil compaction and aneurysm recanalization. This technology may improve anatomic and clinical outcomes in patients harboring intracranial aneurysms.

Endovascular treatment and neurointensive care of ruptured aneurysms

The acute management of aneurysmal SAH requires a comprehensive approach entailing acute critical care and stabilization, occlusion of the aneurysm, and intensive care management of acute neurologic complications. The development of endovascular treatment of aneurysms has added an important, less-invasive treatment to the regimen available in treating aneurysms. An integrated approach of providing critical care before, during, and after the occlusion of the aneurysm is an important concept that should be the goal. Debate and controversy remains regarding which aneurysms are best suited to endovascular treatment or to surgical treatment; an evolving experience and clinical trials will provide further guidance. Nonetheless, some aneurysms may require both surgery and endovascular treatment. Finally, close neurologic observation and directed specialized monitoring techniques are required for providing directed critical care in the acute period after SAH.

Ballonn-assisted Guglielmi detachable coiling of wide-necked aneurysma: Part II--clinical results

OBJECTIVE

To demonstrate the indications and efficacy of balloon-assisted Guglielmi detachable coiling (BAGDC).

METHODS

BAGDC was used for 23 patients (19 women and 4 men; mean age, 55 yr) (17%) of a series of 136 consecutive patients who underwent Guglielmi detachable coiling of aneurysms. Every aneurysm had a wide neck, and 57% were large (11-25 mm in diameter). In each case, a nondetachable silicone balloon was advanced in the parent artery and inflated to occlude the neck of the aneurysm and stabilize the Guglielmi detachable coil delivery microcatheter at the aneurysm neck. Guglielmi detachable coils were then deposited. The balloon was then deflated to verify appropriate coil placement and stability, and finally, the Guglielmi detachable coils were detached. This process was repeated until the aneurysm was suitably embolized.

RESULTS

One hundred percent aneurysm embolization was achieved in 19 patients (83%), and 95 to 100% embolization was achieved in 4 patients (17%). Twenty-two patients (96%) were at their preprocedure neurological baseline after the procedure. There were three complications in the study. One patient died after sustaining subarachnoid hemorrhage-induced vasospasm followed by a hemorrhagic infarction. She had undergone an unsuccessful clip ligation of her aneurysm. A second patient developed an intra-arterial thrombus at the site of balloon deployment. She sustained ischemic events that were treated with thrombolysis and anticoagulation. She made a complete recovery. A third patient developed an intra-arterial thrombus that was noted during the procedure. She was treated with intra-arterial thrombolysis and experienced no clinical sequelae. No permanent complications could be attributed to the BAGDC technique. The median clinical follow-up time was 10 months. No patient required additional treatment or developed a recurrent aneurysm neck or lumen.

CONCLUSION

BAGDC is a promising adjunct to the treatment of wide-necked aneurysms. The balloon serves two purposes: it stabilizes the microcatheter in the aneurysm during coil delivery, and it forces the coil to assume the three-dimensional shape of the aneurysm without impinging on the parent artery.

Balloon-assisted Guglielmi detachable coiling of wide-necked aneurysms: Part I--experimental evaluation

OBJECTIVE

Balloon-assisted technique is a promising technical adjunct to use of Guglielmi detachable coils for embolization of wide-necked aneurysms. In this study using experimental aneurysms in swine, the safety and long-term efficacy of this technique were evaluated.

METHODS

Sixteen wide-necked aneurysms (sidewall model) were surgically created in common carotid arteries of swine. In the acute study of eight aneurysms, intra-aneurysmal pressure changes were recorded during balloon inflation in different positions of the balloon relative to the neck of the aneurysm. In the chronic study, eight aneurysms were treated with this technique, and follow-up angiography was performed 14 days postembolization. The animals were then killed for macroscopic evaluation.

RESULTS

In the acute study, the systolic intra-aneurysmal blood pressure increased with balloon inflation at the distal portion of the neck and with balloon inflation/occlusion across the entire neck of the aneurysm. In the chronic study, seven of eight cases were embolized with satisfactory occlusion, and six showed no coil displacement on the follow-up angiogram. In five cases, macroscopic evaluation of the aneurysm showed that the coils were compacted at the neck of the aneurysm with a concave shape consistent with the shape of the inflated balloon across its neck.

CONCLUSION

This preliminary study indicates that balloon-assisted Guglielmi detachable coiling technology may produce a temporary increase of pressure within the aneurysm while occluding the aneurysmal neck during coil delivery. This sudden change of intra-aneurysmal pressure may potentially be the cause-of aneurysm rupture in the clinical setting. The balloon must be inflated and deflated very slowly to minimize these potentially risky hemodynamic changes. Although angiographic follow-up showed successful obliteration of aneurysms, further long-term angiographic studies are necessary to establish the durability of this technique.

Intraarterial thrombolysis for treatment of acute stroke: experience in 26 patients with long-term follow-up

BACKGROUND AND PURPOSE

Since the approval of intravenous tissue plasminogen activator for acute ischemic stroke, great interest has been generated in cerebral fibrinolysis. Our purpose was to assess long-term outcome and hemorrhagic risk in patients with anterior circulation ischemic stroke treated with intraarterial urokinase.

METHODS

Twenty-six patients were treated within 6 hours of ictus; of these, 21 were followed up for an average of 23 months. Angiographic reperfusion was classified according to thrombolysis in myocardial infarction (TIMI) grades. The Rankin Scale (RS) and the modified Barthel Index (mod BI) were used as outcome measures (good outcome: RS = 0-2, mod BI = 16-20; poor outcome: RS = 3-5, mod BI < or = 15).

RESULTS

Ten of the 21 patients (average age, 48 years) had a good outcome; three (average age, 71 years) had a poor outcome; eight patients (average age, 78 years) died. Partial/complete (successful) recanalization was observed in 11 of 26 patients and minimal or no (unsuccessful) recanalization in 15. Recanalization favored a better outcome: nine of 21 had successful recanalization, with a good outcome in seven; 12 of 21 had unsuccessful reperfusion, with poor outcome/death in nine. Poor outcome was noted in five patients with internal carotid artery (ICA) bifurcation occlusions, four of whom had unsuccessful recanalization and poor outcome or death. Hemorrhage occurred in 10 of the 26 patients, with clinical deterioration in three. The average dose of urokinase was higher in the hemorrhage group, and mortality was higher in patients who hemorrhaged.

CONCLUSION

Intraarterial thrombolysis is feasible in the setting of acute stroke. Successful reperfusion is associated with a better outcome, and the prevalence of hemorrhage does not exceed that which occurs in the natural history of embolic stroke. Poor outcome or death is associated with nonrecanalization, older age, hemorrhage, and ICA bifurcation occlusions.

Endovascular treatment of multiple intracranial aneurysms by using Guglielmi detachable coils

OBJECT

The purpose of this paper is to present the authors' experience with Guglielmi detachable coil (GDC) embolization of multiple intracranial aneurysms and to evaluate the results of this therapy in single-stage procedures.

METHODS

Clinical and angiographic evaluations were performed in 38 consecutive patients with multiple intracranial aneurysms treated by GDC embolization between March 1990 and October 1997. Twenty-nine patients presented with subarachnoid hemorrhage (SAH), four with mass effect, and five were asymptomatic. These 38 patients harbored 101 aneurysms, 79 of which were treated with GDCs, 14 by surgical clipping, and eight were left untreated. Of the GDC-treated lesions, a complete endovascular occlusion was achieved in 55 aneurysms (70%), and 24 (30%) presented neck remnants. Twenty-five patients (66%) underwent GDC embolization of more than one aneurysm in the first session. Eighteen (86%) of 21 patients with acute SAH underwent treatment for all aneurysms within 3 days after admission (15 of 21 in one session). Follow-up angiographic studies in 30 patients demonstrated an unchanged or improved result in 94% of the aneurysms (59 lesions) and coil compaction in 6% (four lesions). The overall clinical outcome was excellent in 34 patients (89%), good in one (3%), fair in one (3%), and death in two (5%).

CONCLUSIONS

Endovascular treatment of multiple intracranial aneurysms, regardless of their location, with GDCs was performed safely in one session, even during the acute phase of SAH. Treatment of all aneurysms in one session protected the patient from rebleeding and eliminated the risk of mistakenly treating only the unruptured aneurysms.

Embolization of incidental cerebral aneurysms by using the Guglielmi detachable coil system

OBJECT

Guglielmi detachable coil (GDC) technology is a valuable therapeutic alternative to the surgical treatment of ruptured or incidental intracranial aneurysms. The authors describe their technical and clinical experience in the use of the GDC technique in patients who underwent endovascular occlusion for the treatment of incidentally found intracranial aneurysms.

METHODS

One hundred fifteen patients with 120 incidentally found intracranial aneurysms underwent embolization by means of the GDC endovascular technique. Ninety-one patients were females and 24 were males. Patient age ranged from 13 to 80 years. In 64 patients the incidental aneurysms were discovered when unrelated nonneurological conditions signaled the need for angiography or magnetic resonance angiography (Group 1). Twenty patients who presented with incidental aneurysms that were discovered during treatment for an acutely ruptured aneurysm underwent treatment of both types of aneurysm during the acute phase of subarachnoid hemorrhage (SAH) (Group 2). Sixteen patients with incidental aneurysms were treated during the chronic phase of SAH (Group 3). Group 4 included 15 patients who had incidental aneurysms associated with brain tumors or arteriovenous malformations. Angiographic results revealed complete or near-complete occlusion in 109 aneurysms (91%) and incomplete occlusion in five aneurysms (4%). Guglielmi detachable coil embolization was attempted unsuccessfully in six aneurysms (5%). One hundred nine patients (94.8%) remained neurologically intact or unchanged from their initial clinical status. Five patients (4.3%) deteriorated as a result of immediate procedural complications. All these complications occurred in the first 50 patients treated in the series. No clinical complications were observed in the last 65 patients. In one patient, a partially embolized aneurysm ruptured 3 years postprocedure. In Groups 1 and 3, the average length of hospitalization was 3.3 days.

CONCLUSIONS

The evolution of GDC technology has proved to provide safe treatment of incidental aneurysms (a morbidity rate of 0% was achieved in the last 65 patients). The topography of the aneurysm and the clinical condition of the patient did not influence final anatomical or clinical outcomes. The GDC technology also confers a positive economic impact by decreasing hospital length of stay and by eliminating the need for postembolization intensive care.

Intra-arterial Cereport (RMP-7) and carboplatin: a dose escalation study for recurrent malignant gliomas

OBJECTIVE

Animal and human studies have shown increased delivery of radiolabeled compounds across the blood-brain-tumor barrier using intra-arterial (IA) Cereport (RMP-7; Alkermes Inc., Cambridge, MA) with a radiolabeled tracer. This present study assesses the safety, tolerance, and preliminary efficacy of the IA administration of carboplatin with Cereport.

METHODS

An open-label dose escalation study of IA Cereport (10-300 ng/kg) with 100 mg of IA carboplatin was conducted in 11 patients with recurrent malignant gliomas and 1 patient treated adjuvantly after radiation therapy. Tumor size and laboratory and clinical statuses were assessed.

RESULTS

Adverse events were mainly neurological in nature and corresponded to the anatomic location of the tumor. Karnofsky performance scale scores did not decline, overall, for those patients who had tumor response. Tumor shrinkage was observed in three of six evaluable patients who received a dose of 300 ng/kg with durable responses of 60, 64, and 106+ weeks.

CONCLUSION

Previous studies have demonstrated increased permeability in human gliomas using IA Cereport. This study demonstrates durable imaging responses using 100 mg of IA carboplatin in combination with Cereport. The drug combination in this patient population seems to be safe and acceptable, providing a novel means of antitumor dose intensification.

Unruptured aneurysms presenting with mass effect symptoms: response to endosaccular treatment with Guglielmi detachable coils. Part I. Symptoms of cranial nerve dysfunction

OBJECT

Embolization of intracranial aneurysms by using Guglielmi detachable coils (GDCs) is proving to be a safe method of protecting aneurysms from rupture. Occasionally, patients with unruptured intracranial aneurysms present with symptoms related to the aneurysm's mass effect on either the brain parenchyma or cranial nerves. In the present study, the authors conducted a retrospective review to evaluate the response to GDC embolization in a series of 19 patients presenting with cranial nerve dysfunction due to mass effect.

METHODS

Aneurysms were classified by size, shape, wall calcification, and amount of intraluminal thrombus. Patients were classified by duration of symptoms prior to GDC treatment (range < 1 month to > 10 years). Clinical assessment was performed within days of the GDC procedure and at later follow-up appointments (range 1-70 months, mean 24 months). In the immediate post-GDC period, four patients experienced worsening of cranial nerve deficits. Two of the four patients had transient worsening of visual acuity, which later improved to better than baseline status. Another patient who had presented with headache and seventh and eighth cranial nerve deficits from a vertebrobasilar junction aneurysm had improvement in these symptoms, but developed a new diplopia. The fourth patient had worsening of her visual acuity, which had not resolved at the 1-month follow-up examination; this patient later underwent surgical decompression.

CONCLUSIONS

On late follow-up review, the response was classified as complete resolution of symptoms in six patients (32%), improvement in eight patients (42%), no significant change in four patients (21%), and symptom worsening in one patient (5%). Patients with smaller aneurysms and those with shorter pretreatment duration of symptoms were more likely to experience an improvement in their symptoms following GDC treatment, although statistical significance was not reached in this series (p=0.603 and p=0.111, respectively). The presence of aneurysmal wall calcification (six patients) or intraluminal thrombus (12 patients) showed no correlation with the response of mass effect symptoms in these patients.

Nonadhesive liquid embolic agent for cerebral arteriovenous malformations: preliminary histopathological studies in swine rete mirabile

OBJECTIVE

To assess acute and chronic histopathological changes observed in a swine arteriovenous malformation model after endovascular delivery of Embolyx E (Micro Therapeutics Inc., San Clemente, CA) and its organic solvent dimethyl sulfoxide (DMSO). To develop standard endovascular delivery techniques of Embolyx through microcatheters into swine rete mirabile (RMB).

METHODS

Forty RMBs in 22 swine were used to analyze acute and chronic angiographic and histological changes after superselective delivery of Embolyx E and/or its organic solvent (DMSO). Four RMBs (two for DMSO and two for Embolyx E study) were used as control specimens. Angiographic and histological evaluations were obtained 18 days, 1 month, 3 months, and 6 months after the procedure. Particular attention was paid to the presence of focal or diffuse angionecrosis, arterial revascularization, and perivascular inflammatory response.

RESULTS

Staged and/or continuous delivery of Embolyx E were performed through the DMSO-compatible microcatheters without untoward catheter "gluing." All subacute/chronic specimens embolized with Embolyx E showed no evidence of angiographic recanalization. Twelve RMBs were used in acute studies, and all specimens showed no evidence of angionecrosis or aggressive inflammatory reaction. Subacute and chronic (total, n = 14) histological examinations of the RMBs showed mild inflammatory response manifested by monocellular infiltration and scattered foreign body giant cell reaction. In the 9 of 14 subacute and chronic specimens, focal disruption of elastica was observed along with embolic materials. Fourteen RMBs in eight swine were used to determine the safety range for DMSO injection. Two RMBs were used as control specimens. Rapid intra-arterial delivery (0.5 ml/5-15 s, n = 6) of DMSO caused angiographic vasospasm and histological endothelial necrosis. Slow injection (0.5 ml/30-120 s, n = 8) of DMSO showed minimum or no angiographic vasospasm, minimal adventitial inflammatory response, and no clinical complications.

CONCLUSION

Embolyx E, an occlusive and nonadhesive embolic agent, is capable of producing permanent occlusion of swine RMB with the development of mild intra- and perivascular inflammatory changes and no clinical complications. The slow endovascular delivery of DMSO produces no untoward angiographic, pathological, or clinical changes. A fast injection of DMSO causes endothelial necrosis and severe inflammatory response in the arterial wall. This embolic material seems to have appropriate biochemical, anatomic, and histopathological characteristics to be used in the treatment of cerebral arteriovenous malformations or vascular cranial base tumors.

Direct arteriovenous fistulas (carotid-cavernous and vertebral-venous). Diagnosis and intervention

Carotid-cavernous and vertebral-venous fistulas are direct arteriovenous fistulas. Their symptoms range from benign to extremely severe ophthalmologic or neurologic complications. Mechanism of symptoms is mostly related to venous drainage. Therapy is widely indicated, as today's endovascular techniques--using mostly detachable balloons and coils--have a high success rate and very few complications.

Transvenous embolization of a dural arteriovenous fistula of the cavernous sinus through the contralateral pterygoid plexus

We report a new transvenous endovascular route for treatment of dural arteriovenous fistulas of the cavernous sinus. The cavernous sinus was approached from the contralateral pterygoid plexus and embolization of a dural fistula was performed successfully with Guglielmi detachable coils.

Intra-arterial administration of carboplatin and the blood brain barrier permeabilizing agent, RMP-7: a toxicologic evaluation in swine

RMP-7 is a bradykinin B2 receptor agonist shown to permeabilize the blood-brain barrier, especially that associated with brain tumors, when administered via both intracarotid and intravenous routes. Both routes of administration are currently being tested in human trials in combination with the chemotherapeutic agent carboplatin as therapy for gliomas. As an essential prerequisite to the initial intracarotid clinical trials, the potential neurotoxicity of intra-arterial administration of RMP-7 (at a high or low dose), alone and in combination with carboplatin, was assessed in anesthetized Red Duroc swine. Five treatment groups were evaluated with each pig receiving a series of alternating, intra-arterial infusions of RMP-7 (or saline) followed by carboplatin (or saline), as follows: (1) vehicle control: saline/saline; (2) carboplatin only control: saline/carboplatin (50 mg total); (3) RMP-7 only control: RMP-7 (750 ng/kg)/saline; (4) low dose combination: RMP-7 (75 ng/kg)/carboplatin (50 mg total); and (5) high dose combination: RMP-7 (750 ng/kg)/carboplatin (50 mg total). For each subject, one of the alternating dosing sequences (above) was repeated four times during a single dosing session which lasted approximately 40 minutes. Assessments during the in-life phase of the study in the pre- and post-treatment periods consisted of heart rate, arterial blood pressure (systolic, diastolic, and mean), blood gases, body weight, general clinical observations (including evaluation for neurological deficit) and clinical pathology (including a comprehensive battery of standard blood coagulation, hematological and serum chemistry tests). In addition, during the time of treatment, heart rate and arterial blood pressure were monitored. The animals were terminated two weeks after dosing and the brain and rete mirabile (distal to site of infusion) were evaluated for gross and histopathological abnormalities. The histopathology analysis included a reader-blinded analysis using low and high power light microscopic examination of both H&E and Kluver-Berrera stained sections through several key cortical and subcortical brain regions. Transient decreases in arterial blood pressure (mean of 10-25 mmHg) were observed in both groups receiving the high dose of RMP-7 (i.e., 750 ng/kg). No other side effects attributable to RMP-7 and/or carboplatin were observed, and clinical observations revealed no evidence of neurologic deficits. Post-mortem examination revealed no evidence of CNS or cerebral vascular pathology attributable to carboplatin and RMP-7. This study demonstrates that intracarotid administration of the maximum tolerated dose of RMP-7 (750 ng/kg) alone, or in combination with carboplatin (50 mg) is not accompanied by any serious adverse effect, apparent cerebrovascular abnormality or neuropathologic consequence and offers further evidence for the safety of this novel therapeutic approach for enhancing delivery of chemotherapeutics to brain tumors.