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

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

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

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

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

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

Safety 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.

Synchronous endoscopy and microsurgery: a novel strategy to approach complex ventricular lesions. Report of three cases.

Simultaneous endoscopic and microsurgical (synchronous) approaches represent a new paradigm in the treatment of complex ventricular lesions. This technique is well suited for lesions that involve multiple ventricular or cisternal compartments, have a nonlinear axis, or adhere to critical anatomical or neurovascular structures. Two distinct operative corridors, one endoscopic and the other microsurgical, are used during synchronous approaches to address such lesions, increasing the likelihood of a safe and complete resection. The authors present the cases of two children and an adult treated via synchronous approaches. All patients had multi-compartmental lesions involving the ventricles and/or cisterns. One patient presented with a suprasellar Rathke cyst with a significant third ventricular component, one with a hypothalamic hamartoma having a substantial cisternal component, and the remaining patient with a choroid plexus papilloma in the left lateral ventricle that extended from midbody to the temporal horn. In the cases of the Rathke cyst and the hamartoma, debulking in the third ventricle and controlled detachment of the lesion from the hypothalamus were undertaken using endoscopy, and simultaneous resection of the suprasellar component was performed through a subfrontal craniotomy. In the case of the choroid plexus papilloma, selective cautery of the choroidal feeding vessels and detachment from the temporal tela choroidea were performed using endoscopy, and the tumor from the ventricular body to the atrium was resected via a craniotomy. In each case the resection concluded with the intersection of endoscopic and microsurgical fields. All three patients had good outcomes. Endoscopic and microsurgical approaches can be used concurrently to treat multicompartment ventricular and/or cisternal lesions with good results. The probable advantages of this method are more complete resection and improved safety.

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.

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.

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.

Biomechanical evaluation of a bioresorbable odontoid screw.

OBJECT: The authors tested the ability of a resorbable cannulated lag screw composed of a polylactide copolymer to repair Type II odontoid fractures. The resorbable screw was evaluated for its ability to restore strength and stiffness to the fractured odontoid process compared with traditional titanium screws. METHODS: Type II odontoid fractures were created in 14 human cadaveric C-2 vertebrae by applying a posterolaterally directed load and piston displacement was measured. Seven of these specimens were repaired using metal screws and seven were repaired using resorbable screws. Specimens were reinjured using the same mechanism as the initial fracture. Values of ultimate strength and stiffness during failure were statistically compared between metal and resorbable screws and between initial fracture and reinjury. CONCLUSIONS: The stiffness and ultimate strength during initial fracture were significantly greater than those during reinjury in specimens repaired using resorbable screws or titanium screws (p < 0.001). The resorbable and titanium screws both restored 31% of the initial ultimate strength of the intact specimen (p = 0.95). The stiffness of the fractured odontoid process was restored to 15 and 23% of its initial value by repair with resorbable and metal screws, respectively (p = 0.07). The mode of failure in resorbable screws was usually breakage or bending, whereas that in metal screws was consistently cutout of the proximal shaft of the screw through the anterior C-2 vertebral body.

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.

Cerebral revascularization performed using posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass. Report of four cases and literature review.

Cerebral revascularization is often required for the surgical treatment of complex intracranial aneurysms. In certain anatomical locations, vascular anatomy and redundancy make in situ bypass possible. The authors present four patients who underwent revascularization performed using the rarely reported posterior inferior cerebellar artery (PICA)-PICA in situ bypass after their aneurysms had been trapped. At Barrow Neurological Institute, between 1991 and the present, four male patients underwent PICA-PICA by-passes to treat aneurysms involving the vertebral artery, the PICA, or both. The mean age of these patients was 34 years (range 5-49 years). Follow-up studies revealed patent bypasses and no evidence of infarction. Patient outcomes were excellent or good. Multiple surgical techniques have been described for revascularization of at-risk cerebral territories. Often, the blood supply must be derived from extracranial sources through a mobilized pedicle or interposited graft. Certain anatomical locations such as the vertebrobasilar junction, the anterior circle of Willis, and the middle cerebral artery bifurcation are amenable to in situ bypass because there is vessel redundancy or proximity to the contralateral analogous vessel. The advantages of an in situ bypass include one suture line, a short bypass distance, and a close match with the caliber of the recipient graft. Although technically challenging, this technique can be successful and should be considered for appropriate candidates.

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.