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nlm-article

Cover Neurosurgical Focus: Video

Extended middle fossa approach for resection of a petroclival meningioma and vestibular schwannoma

Robert C. Rennert, Karol P. Budohoski, Richard K. Gurgel, and William T. Couldwell

A 69-year-old woman with refractory left facial pain and subtle left hearing decline had a 13.0 × 8.1–mm left petrous apex/Meckel’s cave meningioma and an 8.8 × 5.6–mm left intracanalicular vestibular schwannoma. She was otherwise neurologically intact. The anterior petrous and middle fossa approaches provide ideal access to these lesions individually, so an extended middle fossa approach was used to resect both in the same setting. She was neurologically stable postoperatively, except for a transient abducens palsy. Hearing was preserved on audiogram, and 4-month MRI displayed no tumors. The extended middle fossa approach provides excellent exposure of the petrous apex and internal auditory canal.

The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21258

Open access

nlm-article

Cover Neurosurgical Focus: Video

Treatment of a ruptured blister aneurysm of the left internal carotid artery with telescoping Pipeline Flex embolization devices with Shield Technology

Karol P. Budohoski, Robert C. Rennert, Vance Mortimer, William T. Couldwell, and Ramesh Grandhi

Ruptured blister aneurysms have significant rates of morbidity and mortality, but evidence of positive results with use of flow-diverting stents such as the Pipeline embolization device (PED) is growing. The authors describe the staged endovascular treatment of a ruptured left internal carotid artery blister aneurysm in a patient with a Hunt and Hess grade IV subarachnoid hemorrhage. PED placement was done via the common femoral artery using a triaxial delivery system. The telescoping stent technique performed over 48–72 hours achieved sufficient coverage of the aneurysm neck while limiting treatment time during the acute presentation and allowing interim dual antiplatelet treatment. A staged approach allows the targeting of a second PED placement in patients whose aneurysm continues to fill on the first follow-up angiogram. The authors have not experienced increased thromboembolic complications with this approach. Complete occlusion was achieved by postbleed day 8.

The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2264

Free access

nlm-article

Cover Neurosurgical Focus

Role of botulinum neurotoxin–A in cerebral revascularization graft vasospasm prevention: current state of knowledge

Kristine Ravina, Ben A. Strickland, Robert C. Rennert, Joseph N. Carey, and Jonathan J. Russin

Graft stenosis and occlusion remain formidable complications in cerebral revascularization procedures, which can lead to significant morbidity and mortality. Graft vasospasm can result in early postoperative graft stenosis and occlusion and is believed to be at least partially mediated through adrenergic pathways. Despite various published treatment protocols, there is no single effective spasmolytic agent. Multiple factors, including anatomical and physiological variability in revascularization conduits, patient age, and comorbidities, have been associated with graft vasospasm pathogenesis and response to spasmolytics. The ideal spasmolytic agent thus likely needs to target multiple pathways to exert a generalizable therapeutic effect. Botulinum toxin (BTX)–A is a powerful neurotoxin widely used in clinical practice for the treatment of a variety of spastic conditions. Although its commonly described paradigm of cholinergic neural transmission blockade has been widely accepted, evidence for other mechanisms of action including inhibition of adrenergic transmission have been described in animal studies. Recently, the first pilot study demonstrating clinical use of BTX-A for cerebral revascularization graft spasm prevention has been reported. In this review, the mechanistic basis and potential future clinical role of BTX-A in graft vasospasm prevention is discussed.

Free access

nlm-article

Cover Neurosurgical Focus

Cilostazol for the management of moyamoya disease: a systematic review of the early evidence, efficacy, safety, and future directions

Aidin Abedi, Saman Sizdahkhani, Wooseong Choi, Vincent N. Nguyen, Robert C. Rennert, and Jonathan J. Russin

Surgical revascularization remains the standard treatment for symptomatic moyamoya disease (MMD). As with any major surgical treatment, revascularization is associated with risks and limitations, denoting the need for noninvasive treatments to improve ischemic symptoms and prevent strokes. Cilostazol is a selective phosphodiesterase III inhibitor with antiplatelet, antithrombotic, and vasodilatory effects commonly used in peripheral vascular disease. Clinical studies assessing the efficacy of cilostazol in the management of stroke and MMD were recently reported, although a comprehensive assessment of the overall evidence is lacking. A systematic scoping review was conducted to assess the early evidence on cilostazol administration in patients with MMD. The inclusion criteria encompassed original human studies primarily focused on cilostazol’s safety, efficacy, or utilization in managing MMD patients. A search of the PubMed database was conducted in June 2023, yielding 5 peer-reviewed publications that satisfied the inclusion criteria and were subjected to narrative synthesis. Risk of bias assessment was not applicable due to the scoping nature of this review. East Asian studies demonstrate increasing rates of cilostazol prescriptions for patients with MMD. In a large population-based study, cilostazol was compared to other antiplatelet medications and yielded the largest decrease in mortality among patients with newly diagnosed MMD. Other studies reported significant improvements in cerebral blood flow and cognitive function, which were deemed to be independent of one another. There are limited data on the safety profile of cilostazol in the MMD population, although the evidence derived from various studies performed in the general stroke population can likely provide insights into its potential utility in MMD patients. Cilostazol targets several critical pathways involved in the pathophysiology of MMD. The evidence corroborates the potential benefits of cilostazol for the management of MMD, although these findings should be interpreted with caution due to the small number of studies and lack of randomized trials. Subgroups of patients need to be identified who can safely undergo medical management in lieu of revascularization surgery or to improve surgical outcomes. Additional studies are needed to assess the efficacy and safety of cilostazol therapy, especially in Western populations.

Restricted access

nlm-article

Cover Journal of Neurosurgery

Pedicled temporoparietal fascial flap for combined revascularization in adult moyamoya disease

Kristine Ravina, Robert C. Rennert, Ben A. Strickland, Mark Chien, Joseph N. Carey, and Jonathan J. Russin

Moyamoya disease (MMD) is a progressive, idiopathic cerebrovascular occlusive disease. Various revascularization techniques including direct, indirect, and combined microvascular bypasses have been described. This article presents a modified revascularization technique for MMD utilizing a pedicled temporoparietal fascial flap (TPFF) for combined revascularization. This technique combines a large area of coverage for indirect revascularization with the benefits of a direct bypass. The pedicled TPFF also benefits from intact venous drainage to minimize the risk of flap swelling that could result in complications from mass effect.

Free access

nlm-article

Cover Neurosurgical Focus

Safety of stereotactic laser ablations performed as treatment for glioblastomas in a conventional magnetic resonance imaging suite

Robert C. Rennert, Kate T. Carroll, Mir Amaan Ali, Thomas Hamelin, Leon Chang, Brian P. Lemkuil, and Clark C. Chen

OBJECTIVE

Stereotactic laser ablation (SLA) is typically performed in the setting of intraoperative MRI or in a staged manner in which probe insertion is performed in the operating room and thermal ablation takes place in an MRI suite.

METHODS

The authors describe their experience, in which SLA for glioblastoma (GBM) treatment was performed entirely within a conventional MRI suite using the SmartFrame stereotactic device.

RESULTS

All 10 patients with GBM (2 with isocitrate dehydrogenase 1 mutation [mIDH1] and 8 with wild-type IDH1 [wtIDH1]) were followed for > 6 months. One of these patients underwent 2 independent SLAs approximately 12 months apart. Biopsies were performed prior to SLA for all patients. There were no perioperative morbidities, wound infections, or unplanned 30-day readmissions. The average time for a 3-trajectory SLA (n = 3) was 436 ± 102 minutes; for a 2-trajectory SLA (n = 4) was 321 ± 85 minutes; and for a single-trajectory SLA (n = 4) was 254 ± 28 minutes. No tumor recurrence occurred within the blue isotherm line ablation zone, although 2 patients experienced recurrence immediately adjacent to the blue isotherm ablation line. Overall survival for the patient cohort averaged 356 days, with the 2 patients who had mIDH1 GBMs exhibiting the longest survival (811 and 654 days).

CONCLUSIONS

Multitrajectory SLA for treatment of GBM can be safely performed using the SmartFrame stereotactic device in a conventional MRI suite.

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nlm-article

Cover Journal of Neurosurgery

Concurrence of chromosome 6 chromothripsis and glioblastoma metastasis

Robert C. Rennert, Reid R. Hoshide, Jason W. Signorelli, Deirdre Amaro, Jayson A. Sack, Cameron W. Brennan, and Clark C. Chen

The authors report an unusual case of a widely metastatic glioblastoma. DNA copy number microarray profile of the resected specimen revealed complex rearrangements found throughout chromosome 6, a phenomenon known as chromothripsis. Such chromothripsis pattern was not observed in 50 nonmetastatic glioblastoma specimens analyzed. Analysis of the 1000+ gliomas profiled by The Cancer Genome Atlas (TCGA) data set revealed one case of chromosome 6 chromothripsis resembling the case described here. This TCGA patient died within 6 months of undergoing tumor resection. Implications of these findings are reviewed in the context of the current literature.

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nlm-article

Cover Journal of Neurosurgery: Spine

Hemorrhagic intramedullary solitary fibrous tumor of the conus medullaris: case report

Corey T. Walker, Chiazo S. Amene, Jeffrey S. Pannell, David R. Santiago-Dieppa, Robert C. Rennert, Lawrence A. Hansen, and Alexander A. Khalessi

The differential diagnosis of spinal tumors is guided by anatomical location and imaging characteristics. Diagnosis of rare tumors is made challenging by abnormal features. The authors present the case of a 47-year-old woman who presented with progressive subacute right lower-extremity weakness and numbness of the right thigh. Physical examination further revealed an extensor response to plantar reflex on the right and hyporeflexia of the right Achilles and patellar reflexes. Magnetic resonance imaging of the lumbar spine demonstrated an 8-mm intramedullary exophytic nodule protruding into a hematoma within the conus medullaris. Spinal angiography was performed to rule out an arteriovenous malformation, and resection with hematoma evacuation was completed. Pathological examination of the resected mass demonstrated a spindle cell neoplasm with dense bundles of collagen. Special immunostaining was performed and a diagnosis of solitary fibrous tumor (SFT) was made. SFTs are mesenchymally derived pleural neoplasms, which rarely present at other locations of the body, but have been increasingly described to occur as primary neoplasms of the spine and CNS. The authors believe that this case is unique in its rare location at the level of the conus, and also that this is the first report of a hemorrhagic SFT in the spine. Therefore, with this report the authors add to the literature the fact that this variant of an increasingly understood but heterogeneous tumor can occur, and therefore should be considered in the differential of clinically similar tumors.

Free access

nlm-article

Cover Journal of Neurosurgery: Pediatrics

Middle fossa approach for a pediatric facial nerve meningioma

Robert C. Rennert, Danielle M. Levy, Jillian Plonsker, Jeffrey A. Steinberg, Rick A. Friedman, John R. Crawford, and Michael L. Levy

Pediatric cerebellopontine angle (CPA) meningiomas are extremely rare and are usually treated with a retrosigmoid surgical approach or radiation. The authors present the use of a middle fossa approach for the treatment of a symptomatic CPA meningioma in a 22-month-old female. The patient initially presented at 17 months with isolated progressive, long-standing right-sided facial weakness. MRI demonstrated a 5.0 × 5.0–mm right CPA lesion just superior to the cisternal segment of cranial nerve (CN) VII, which demonstrated growth on interval imaging. At 22 months of age she underwent a successful middle fossa craniotomy, including wide exposure of the porus acusticus, allowing for a gross-total resection with preservation of CNs VII and VIII. Pathological analysis revealed a WHO grade I meningioma. The patient remained neurologically stable on follow-up. The middle fossa approach can be used to safely access the CPA in properly selected pediatric patients.

Free access

nlm-article

Cover Journal of Neurosurgery: Pediatrics

Initial experience with Pipeline embolization of intracranial pseudoaneurysms in pediatric patients

Karol P. Budohoski, Raj Thakrar, Zoya Voronovich, Robert C. Rennert, Craig Kilburg, Ramesh Grandhi, William T. Couldwell, Douglas L. Brockmeyer, and Philipp Taussky

OBJECTIVE

Flow-diverting devices have been used successfully for the treatment of complex intracranial vascular injuries in adults, but the role of these devices in treating iatrogenic and traumatic intracranial vascular injuries in children remains unclear. The authors present their experience using the Pipeline embolization device (PED) for treating intracranial pseudoaneurysms in children.

METHODS

This single-center retrospective cohort study included pediatric patients with traumatic and iatrogenic injuries to the intracranial vasculature that were treated with the PED between 2015 and 2021. Demographic data, indications for treatment, the number and sizes of PEDs used, follow-up imaging, and clinical outcomes were analyzed.

RESULTS

Six patients with a median age of 12 years (range 7–16 years) underwent PED placement to treat intracranial pseudoaneurysms. There were 3 patients with hemorrhagic presentation, 2 with ischemia, and 1 in whom a growing pseudoaneurysm was found on angiography. Injured vessels included the anterior cerebral artery (n = 2), the supraclinoid internal carotid artery (ICA, n = 2), the cavernous ICA (n = 1), and the distal cervical ICA (n = 1). All 6 pseudoaneurysms were successfully treated with PED deployment. One patient required re-treatment with a second PED within a week because of concern for a growing pseudoaneurysm. One patient experienced parent vessel occlusion without neurological sequelae.

CONCLUSIONS

Use of the PED is feasible for the management of iatrogenic and traumatic pseudoaneurysms of the intracranial vasculature in children, even in the setting of hemorrhagic presentation.