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

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

Application of a novel headrest system for odontoid screw fixation. Technical note.

The authors describe a unique headholder device adapted to facilitate the placement of anterior odontoid screws. The patient's head is affixed in the headholder equipped with an articulating arm that can be placed in a paramedian fashion. This configuration rigidly fixates the head and provides an unencumbered open-mouth view of the odontoid using radiographic images, thus making screw placement easier.

Durectomy and reconstruction for the treatment of a recurrent spinal meningioma. Case report.

The management of spinal meningiomas with extensive involvement of the dura mater is controversial. The principal difficulty in performing a resection is the potential for complications associated with this approach. The authors present the case of a pregnant 35-year-old woman in whom bilateral lower-extremity numbness, weakness, gait ataxia, and myelopathy developed. Magnetic resonance imaging showed a recurrent thoracic meningioma with extensive infiltration of the dura mater. Durectomy, complete resection, and reconstruction were performed. The patient has not experienced a recurrence 21 months after her treatment. This case illustrates that thoracic spinal meningiomas with extensive dural involvement can be resected safely with a complete durectomy. The novel dural reconstruction involving the implantation of a fascia lata and bovine pericardium allograft is an effective way to reconstruct the dura to create an adequate barrier to cerebrospinal fluid.

Antiplatelet therapy in neuroendovascular therapeutics.

Our understanding of the pharmacology of antiplatelet therapy continues to evolve rapidly. Although the existing data are primarily generated in the setting of interventional and preventative cardiology studies, these data may be extrapolated to guide the rational application of these agents in neuroendovascular procedures. Platelet function testing represents an increasingly available and practical method by which to verify the adequacy of therapy and guide clinical decision making. The optimal application of these agents will undoubtedly improve the risk profile of neuroendovascular procedures, increase the success rate of acute stroke intervention, and facilitate more effective secondary stroke prevention.

Combined skull base approaches to the posterior fossa. Technical note.

Combined approaches to the skull base provide maximal exposure of the complex and eloquent anatomical structures contained within the posterior fossa. Common to these combined exposures are variable degrees of petrous bone removal. Understanding the advantages of each approach is critical when attempting to balance increases in operative exposure against the risk of potential complications. Despite their risks, aggressive combined exposures to the posterior fossa enable the greatest degree of visualization of the anatomy. Consequently, surgeons can approach lesions with maximal margins of safety, which cannot otherwise be realized. To minimize morbidity in all cases, the approach chosen must be applied individually, depending on the lesion and the patient's characteristics.

Endovascular management of intracranial vertebral artery dissecting aneurysms.

OBJECT: Intracranial vertebral artery (VA) dissecting aneurysms often present with severe subarachnoid hemorrhage (SAH) and dramatic neurological injury. The authors reviewed the management of 23 cases in an effort to evaluate treatment efficacy and outcomes. METHODS: The records of 23 patients who underwent endovascular treatment were reviewed to determine symptoms, type of therapy, complications, and clinical outcomes. All patients were evaluated using records kept in a prospectively maintained database. Ten men and 13 women (age range 35-72 years; mean age 49 years) were treated over an 8-year period. Twelve patients presented with poor-grade SAH, five with good-grade SAH, three with headache, and two with stroke. The other patient's aneurysm was discovered incidentally. Treatment included coil occlusion of the artery at the aneurysm in 21 patients and stent-assisted coil placement in two. Parent artery sacrifice was successful in all cases, whereas both patients treated with stent-assisted coil insertion suffered recurrences. No patient sustained permanent complications as a result of treatment. Two patients died due to the severity of their original SAH. Findings were normal in 14 patients on follow-up review (including five of the 12 presenting with poor-grade SAH), five had fixed neurological deficits but were able to care for themselves, and one was permanently disabled. CONCLUSIONS: Despite their often aggressive neurological presentation, intracranial VA dissecting aneurysms can be managed safely with coil occlusion of the lesion and/or parent artery. Even patients presenting in poor neurological condition may improve dramatically.

In-stent stenosis as a delayed complication of neuroform stent-supported coil embolization of an incidental carotid terminus aneurysm.

The Neuroform stent is the first microcatheter-delivered stent designed specifically for the treatment of cerebral aneurysms. The stent functions primarily to provide durable parent vessel protection during the embolization of broad-necked cerebral aneurysms. The present case report demonstrates in-stent stenosis occurring as a delayed complication of Neuroform stent-supported coil embolization of an unruptured cerebral aneurysm.

Surgical management of cavernous malformations involving the cranial nerves.

OBJECTIVE: To analyze the indications and techniques pertinent to the treatment of cranial nerve (CN) cavernous malformations (CMs). METHODS: CN CMs are lesions isolated to the CNs. CMs affecting the optic nerve (CN II), oculomotor nerve (CN III), facial/vestibulocochlear complex (CN VII and CN VIII), and hypoglossal nerve (CN XII) have been described. The records for six patients were reviewed with respect to lesion location, symptoms, surgical approach, and therapeutic considerations. This is the largest series of CMs isolated to CNs reported to date. RESULTS: Three female patients and three male patients (age range, 28-76 yr; mean age, 41 yr) presented with six CN lesions; four lesions involved the optic chiasm and two involved CN VII and CN VIII. The patients with chiasmatic lesions presented with acute visual deterioration. Both patients with CN VII/CN VIII lesions exhibited acute hearing loss. The level of deterioration suggested CM hemorrhage. Orbitozygomatic craniotomies were performed for chiasmatic lesions, and retrosigmoid craniotomies were performed for cerebellopontine angle lesions. All patients experienced symptom improvement after surgery. One chiasmatic lesion recurred after 2 years and required resection. CONCLUSION: CN CMs present with site-specific symptoms and require complex surgical techniques for resection. These lesions are frequently symptomatic, because of the eloquence of the tissue of origin. Therefore, all CN CMs should be resected. Subtotal resection uniformly results in disease and symptom recurrence. CN CMs can be resected safely, with preservation of CN function.

Intraoperative Iso-C C-arm navigation in craniospinal surgery: the first 60 cases.

OBJECTIVE: The intraoperative Iso-C C-arm (Siremobil Iso-C 3D; Siemens Medical Solutions, Erlangen, Germany) provides a unique ability to acquire and view multiplanar three-dimensional images of intraoperative anatomy. Registration for intraoperative surgical navigation may be automated, thus simplifying the operative workflow. METHODS: Iso-C C-arm intraoperative fluoroscopy acquires 100 images, each of which must be 1.8 degrees in a circumferential fashion about an "isocentric" point in space. The system generates a high-resolution isotropic three-dimensional data set that is available immediately after the 90-second C-arm rotation. The data set is ported to the image-guided workstation, registration is immediate and automated, and the surgeon can navigate with millimetric accuracy. The authors prospectively examined data from the initial 60 patients examined with the Iso-C, among whom were cases of anterior and posterior spinal instrumentation from the occiput to the sacrum. Percutaneous and minimally invasive spinal and cranial procedures were also included. RESULTS: Automated registration for image-guided navigation was attainable for anterior and posterior cases from the cranial base and entire spine. In most cases, intraoperative postprocedural imaging with the Iso-C mitigated the need for postoperative imaging. CONCLUSION: Intraoperative Iso-C three-dimensional scanning allows real-time feedback during cranial base and spinal surgery and during procedures involving instrumentation. In most cases, it obviates the need for postoperative computed tomography. Its usefulness is in its simplicity, and it can be easily adapted to the operating room workflow. When coupled with intraoperative navigation, this new technology facilitates complex neurosurgical procedures by improving the accuracy, safety, and time of surgery.

High cervical disc herniation presenting with C-2 radiculopathy. Case report and review of the literature.

The authors report the case of a 78-year-old man with a C2-3 disc herniation that had migrated rostrally, causing C-2 radiculopathy. The C-2 radiculopathy manifested immediately after the patient underwent placement of a ventriculoperitoneal shunt for normal-pressure hydrocephalus. Myelography and computerized tomography scanning of the cervical spine revealed an extradural lesion anterolateral to the thecal sac eccentric to the right. The patient underwent a C1-3 laminectomy, C-2 nerve root decompression, and excision of the lesion. Postoperatively the patient's radiculopathy resolved completely. To the authors' knowledge, this is the first case of a C2-3 disc herniation manifesting as C-2 radiculopathy and treated via a posterior extradural approach.

Lateral inferior cerebellar peduncle approach to dorsolateral medullary cavernous malformation.

OBJECT: Brainstem cavernous malformations (BSCMs) present a unique therapeutic challenge to neurosurgeons. Resection of BSCMs is typically reserved for lesions that reach pial or ependymal surfaces. The current study investigates the lateral inferior cerebellar peduncle as a corridor to dorsolateral medullary BSCMs. METHODS: In this retrospective review, the authors present the cases of 4 patients (3 women and 1 man) who had a symptomatic dorsolateral cavernous malformation with radiographic and clinical evidence of hemorrhage. RESULTS: All patients underwent excision of the cavernous malformation via a far-lateral suboccipital craniotomy through the foramen of Luschka and with an incision in the inferior cerebellar peduncle. On intraoperative examination, 2 of the 4 patients had hemosiderin staining on the surface of the peduncle. All lesions were completely excised and all patients had a good or excellent outcome (modified Rankin Scale scores of 0 or 1). CONCLUSIONS: This case series illustrates that intrinsic lesions of the dorsolateral medulla can be safely removed laterally through the foramen of Luschka and the inferior cerebellar peduncle.

Histopathological assessment of fatal ipsilateral intraparenchymal hemorrhages after the treatment of supraclinoid aneurysms with the Pipeline Embolization Device.

OBJECT: Delayed ipsilateral intraparenchymal hemorrhage has been observed following aneurysm treatment with the Pipeline Embolization Device (PED). The relationship of this phenomenon to the device and/or procedure remains unclear. The authors present the results of histopathological analyses of the brain sections from 3 patients in whom fatal ipsilateral intracerebral hemorrhages developed several days after uneventful PED treatment of supraclinoid aneurysms. METHODS: Microscopic analyses revealed foreign material occluding small vessels within the hemorrhagic area in all patients. Further analyses of the embolic materials using Fourier transform infrared (FTIR) spectroscopy was conducted on specimens from 2 of the 3 patients. Although microscopically identical, the quantity of material recovered from the third patient was insufficient for FTIR spectroscopy. RESULTS: FTIR spectroscopy showed that the foreign material was polyvinylpyrrolidone (PVP), a substance that is commonly used in the coatings of interventional devices. CONCLUSIONS: These findings are suggestive of a potential association between intraprocedural foreign body emboli and post-PED treatment-delayed ipsilateral intraparenchymal hemorrhage.

Microsurgical treatment of pediatric intracranial aneurysms: long-term angiographic and clinical outcomes.

BACKGROUND: Pediatric aneurysms are rare and complex to treat. Long-term angiographic and clinical data after microsurgical or endovascular therapies are lacking. OBJECTIVE: To study the clinical and radiographic outcomes in aneurysms in pediatric patients treated with microsurgery. METHODS: Between 1989 and 2005, 48 patients

Pleomorphic xanthoastrocytoma presenting with life-threatening hemorrhage in a child.

Pleomorphic xanthoastrocytomas are glial-based tumors that arise most frequently in young patients and usually follow a more benign and indolent clinical course than their other glial-based tumor counterparts. These tumors most frequently present with seizures, and only 3 previous case reports exist of hemorrhagic tumor as the clinical presentation. The authors present the first case of life-threatening intracerebral hemorrhage from pleomorphic xanthoastrocytoma in a child.

Resolution of mydriatic pupil after angioplasty and stenting of cervical internal carotid artery dissection: case report.

OBJECTIVE: A patient with cervical internal carotid artery (ICA) dissection presented with visual loss and a mydriatic pupil that resolved after angioplasty and stenting. CLINICAL PRESENTATION: A 49-year-old woman presented with a unilateral dilated tonic pupil and transient monocular visual loss and subsequently developed speech disturbance. Angiography revealed a left cervical ICA dissection with significant luminal narrowing. The ophthalmic artery filled retrograde through external carotid artery branches and reconstituted the supraclinoid ICA. Computed tomographic perfusion showed significant hypoperfusion of the left hemisphere. Magnetic resonance imaging showed punctate boundary zone infarcts. INTERVENTION: The patient experienced pressure-dependent left hemispheric transient ischemic attacks and pressure-dependent ocular findings despite anticoagulation. She underwent uncomplicated left ICA angioplasty and stenting. The flow through the ophthalmic artery became anterograde. The tonic pupil returned to symmetry with the contralateral pupil, and the patient's symptoms resolved completely. CONCLUSION: Cervical ICA dissection can manifest with a tonic mydriatic pupil. Treatment with angioplasty and stenting of the dissected segment can restore flow and resolve the pupillary abnormality. A pathophysiological mechanism for the mydriasis is proposed.

Giant, partially thrombosed aneurysm develops after remote angiographically negative subarachnoid hemorrhage: case report.

OBJECTIVE: This is the first report of the rupture of a giant aneurysm in a patient who sustained a remote angiographically negative subarachnoid hemorrhage (SAH). CLINICAL PRESENTATION: A 62-year old woman initially presented with a Fisher Grade III SAH 9 years ago. Her evaluation, which included cerebral angiography, magnetic resonance imaging scans, and magnetic resonance angiography of the head and neck, failed to reveal the cause of the hemorrhage. Nine years after her initial hemorrhage, the patient presented with a Fisher Grade IV SAH and a giant right supraclinoid internal carotid artery aneurysm. INTERVENTION: Computed tomographic and catheter angiography showed a partially thrombosed giant aneurysm of the right supraclinoid internal carotid artery. She underwent clip reconstruction and obliteration of the aneurysm. Review of her previous angiograms and magnetic resonance imaging scans did not show an aneurysm in its nascency. CONCLUSION: Initial catheter angiography and magnetic resonance imaging scans may fail to disclose a subtle dissection or blister aneurysm as a cause for SAH. As in our case, the dissection or blister may progress to a giant aneurysm with time.

Surgical treatment of high-risk intracranial dural arteriovenous fistulae: clinical outcomes and avoidance of complications.

OBJECTIVE: An increasing number of intracranial dural arteriovenous fistulae (DAVFs) are amenable to endovascular treatment. However, a subset of patients with high-risk lesions requires surgical intervention for complete obliteration. We reviewed our experience with the surgical management of high-risk intracranial DAVFs and offer recommendations to minimize complications based on fistula location and type. METHODS: Hospital records for 53 patients (16 women, 37 men) with high-risk intracranial DAVFs treated surgically between 1995 and 2004 were reviewed to determine their presenting symptoms, location, endovascular and surgical interventions, angiographic outcome, and treatment complications. Most patients (76%) presented with intracranial hemorrhage, progressive neurological deficits, or seizures. All patients had high-risk angiographic features such as cortical venous drainage or venous varix. Preoperative embolization was performed in 27 patients. Surgical approaches were tailored to the lesion location. Fistulae were located in the transverse-sigmoid junction (n = 18), tentorium (n = 17), ethmoid (n = 7), superior sagittal sinus (n = 6), torcula (n = 4), and sphenoparietal sinus (n = 3). RESULTS: At the time of the last follow-up evaluation, 49 patients (92%) had good or excellent outcomes (Glasgow Outcome Scale score, 4 or 5) and three (6%) were deceased. Five patients had a residual fistula. One residual spontaneously thrombosed, one was treated with gamma knife radiosurgery, and two were successfully embolized. The overall morbidity and mortality rate was 13%. CONCLUSION: Despite fulminant presenting symptoms, high-risk intracranial DAVFs can be successfully managed with good outcomes. When anatomic features prevent endovascular access, or embolization fails to obliterate the lesion, urgent surgical treatment is indicated. Patients with residual filling of the DAVF should be considered for adjuvant therapy, including further embolization or radiosurgery.

Resolution of hemifacial spasm after surgical obliteration of a tentorial arteriovenous fistula: case report.

OBJECTIVE AND IMPORTANCE: We describe a patient with a tentorial dural arteriovenous fistula who presented with ipsilateral hemifacial spasm. CLINICAL PRESENTATION: A 50-year-old man sought treatment for left facial twitching that worsened over 6 months. Magnetic resonance imaging and catheter angiography demonstrated a left tentorial dural arteriovenous fistula. INTERVENTION: The patient underwent a retrosigmoid craniotomy and ligation of the draining vein at the site of the fistula. Intraoperative angiography showed complete obliteration of the fistula. The patient's hemifacial spasm improved significantly after the fistula was obliterated. CONCLUSION: Posterior fossa arteriovenous fistulas can present with a hemifacial spasm related to compression of the facial nerve by arterialized leptomeningeal veins. Microsurgical obliteration of the fistula can resolve the related symptoms.