Reappraisal of intradural findings in Chiari malformation type I.

OBJECTIVE: Management of Chiari malformation type I (CM-I) requires the functional restoration of an obstructed cisterna magna. In posterior fossa decompression with duraplasty (PFDD), various intradural pathologies are suggested to alter CSF flow at the craniocervical junction and require surgical correction. However, reports of the spectrum of intraoperative intradural findings and their nuances are scarce, especially those characterizing rarer findings pertaining to the vascular structures and vascular compression. METHODS: The authors conducted a retrospective cohort analysis of adults and children who underwent first-time PFDD for CM-I (2011-2021), with and without syringomyelia. The surgical reports and intraoperative videos were reviewed, and the frequency and nature of the intradural observations in regard to the tonsils, arachnoid, and vasculature were analyzed along with the clinical findings and surgical outcomes. RESULTS: All 180 patients (age range 1-72 years; median [interquartile range] 24 (14-38) years; 37% of patients were children < 21 years of age) exhibited multiple intradural findings, with a median of 7 distinct concurrent observations in each patient. Novel findings not previously reported included posterior inferior communicating artery (PICA) branches compressing the neural elements at the cervicomedullary junction (26.7%). Other common findings included arachnoid adhesions (92.8%), thickening (90.6%), webs at the obex (52.2%), tonsillar gliosis (57.2%), tonsillar hypertrophy (18.3%), adhesions obstructing the foramen of Magendie (FoM) (62.2%), PICA obstruction of the FoM (17.2%), and dural scarring (87.8%). Tonsillar gliosis and intertonsillar adhesions obstructing the FoM were more common in children than adults. Tonsillar gliosis and arachnoid webs were more common among syringomyelia patients. After multivariable adjustment, none of the observed findings were independently associated with syringomyelia, preoperative symptoms, or postoperative improvement. The vast majority of patients improved postoperatively. The complication rate was low: 1.2% of patients required revision PFDD at > 3 years postoperatively, 3.6% experienced other operative complications, and 0% had CSF leaks. CONCLUSIONS: The diversity of intradural findings and observations revealed in this study suggests that obstructive and compressive structural anomalies may be more common than previously reported among CM-I patients, both those patients with and those without syringomyelia and especially those with obstructive and compressive PICA branches. Although the authors cannot conclude that all these findings are necessarily pathological, further study may determine how they contribute to CM-I pathology and symptomatology in the setting of a compromised cisterna magna.

Rubber Bullet Induced Traumatic Brain Injury.

ABSTRACT: Rubber bullets have long been known to cause, on rare occasions, traumatic brain injury (TBI). However, neurosurgical literature on this occurrence is limited, and no focused review of this injury pattern has been conducted. The authors present the case of a 28-year-old male struck by a rubber bullet in the left periorbital region, causing TBI in addition to complete left visual loss and complex facial fractures. After developing a cerebrospinal fluid (CSF) leak, the patient was taken to the operating room for combined neurosurgical-craniofacial intervention. Utilizing frameless intraoperative computation tomography navigation assistance, a successful repair was made of both the patient's CSF leak and complex craniofacial injuries. TBI due to a rubber bullet is a rare but severe occurrence. Unfortunately, much of the limited literature on this topic is bereft of demographic, clinical course, injury pattern, and imaging data. Presented here is the first operative case report of TBI due to a rubber bullet. Volume rendered imaging is provided to demonstrate the extent of trauma incurred. Additionally, a methodology for frameless intraoperative computation tomography navigation assistance is shared for consideration, as it served as a helpful adjunct for a combined intracranial-craniofacial surgical repair. The experience of treating the patient's traumatic CSF leak in the context of severe craniofacial and ophthalmologic injuries highlights the need for a multidisciplinary surgical approach that may arise when treating patients with TBI due to a rubber bullet.

BRAF-mutated suprasellar glioblastoma mimicking craniopharyngioma: illustrative case.

BACKGROUND: Suprasellar masses commonly include craniopharyngiomas and pituitary adenomas. Suprasellar glioblastoma is exceedingly rare with only a few prior case reports in the literature. Suprasellar glioblastoma can mimic craniopharyngioma or other more common suprasellar etiologies preoperatively. OBSERVATIONS: A 65-year-old male with no significant history presented to the emergency department with a subacute decline in mental status. Work-up revealed a large suprasellar mass with extension to the right inferior medial frontal lobe and right lateral ventricle, associated with significant vasogenic edema. The patient underwent an interhemispheric transcallosal approach subtotal resection of the interventricular portion of the mass. Pathological analysis revealed glioblastoma, MGMT partially methylated, with a BRAF V600E mutation. LESSONS: Malignant glioblastomas can mimic benign suprasellar masses and should remain on the differential for a diverse set of brain masses with a broad range of radiological and clinical features. For complex cases accessible from the ventricle where the pituitary complex cannot be confidently preserved via a transsphenoidal approach, an interhemispheric approach is also a practical initial surgical option. In addition to providing diagnostic value, molecular profiling may also reveal therapeutically significant gene alterations such as BRAF mutations.

Diffuse-type tenosynovial giant cell tumor between the suboccipital bone and posterior C1 arch: illustrative case.

BACKGROUND: Tenosynovial giant cell tumor (TGCT) occurs most commonly in the appendicular skeleton and is only rarely found in the vertebral column. Lesions of the craniocervical junction are particularly rare, with only 4 cases reported in the literature. The authors describe the case of a diffuse-type TGCT at the craniocervical junction. OBSERVATIONS: A patient presented with a 1-year history of right-sided neck pain and bilateral neurological symptoms in the distribution of the right occipital nerve. A 20-mm homogeneously contrast-enhancing mass in the suboccipital and posterior C1 region was discovered on magnetic resonance imaging of the cervical spine. The tumor was operated on via a posterior approach, and gross-total resection (GTR) was achieved. Immunohistochemical (IHC) examination revealed a diffuse-type TGCT. The patient had an uneventful recovery. LESSONS: TGCT can arise at the craniocervical junction and is easily misdiagnosed because of its rare occurrence. IHC examination of a tumor specimen should be done to confirm the diagnosis. GTR is the objective when treating these tumors, especially when they are the diffuse type, as they have a high recurrence rate. Radiation and small-molecule therapies are viable postoperative therapies if GTR cannot be achieved or in cases of recurrence.

Dual antiplatelet use in the management of COVID-19 associated acute ischemic stroke reocclusion.

INTRO: SARS-CoV-2 (COVID-19) infection is associated with acute ischemic stroke (AIS), which may be due to a prothrombotic state. Early reports have suggested high rates of reocclusion following mechanical thrombectomy (MT) with poor radiographic and clinical outcomes. We report our early experience using intra-procedural antithrombotics to address SARS-CoV-2 reocclusion. METHODS: We identified 6 patients that experienced early reocclusion after MT for COVID-19-associated AIS through retrospective chart review abstracting their basic demographics, COVID-19 status, and stroke management. All these patients were treated after reocclusion with aspirin and cangrelor intra-procedurally, the latter of which was converted to ticagrelor post-procedurally. Some patients additionally received argatroban infusion intraprocedurally. RESULTS: Mean age was 54. There were 3 post-procedural and 3 intra-procedural re-occlusions. After repeat thrombectomy and treatment with aspirin and cangrelor, those with post-procedure reocclusion did not show further reocclusion, while those with intra-procedural reocclusion showed radiographic improvement with intraprocedural cangrelor administration. Outcomes for these patients were poor, with a median mRS of 4. Two patients developed petechial hemorrhage of their stroke which was managed conservatively, and one developed a retroperitoneal hemorrhage from femoral access requiring transfusion. There were no patients who developed new parenchymal hematomas. CONCLUSION: COVID-19 AIS may be associated with a hypercoagulable state which risks malignant reocclusion complicating MT. We found antithrombotic treatment periprocedural cangrelor with or without argatroban transitioned to oral aspirin with ticagrelor to be a viable method for management of these patients.

Initial experience with transcarotid arterial revascularization with flow reversal in the management of symptomatic carotid stenosis.

OBJECTIVE: The aim of this study was to evaluate the efficacy of transcarotid arterial revascularization (TCAR) as a viable intervention in the treatment of symptomatic carotid artery stenosis. METHODS: The authors performed a retrospective review of prospectively collected data of the first 62 consecutive patients treated at Rhode Island Hospital in Providence, Rhode Island, who underwent a TCAR for symptomatic carotid artery stenosis between November 11, 2020, and March 31, 2022. Relevant demographic, comorbidity, and perioperative data were extracted through retrospective chart review. Patients with asymptomatic carotid artery stenosis were excluded. The authors also evaluated patients using pertinent physiological and anatomical high-risk criteria as described in the ROADSTER trial. Risk factors were aggregated to form a composite risk total for every patient. The primary outcome of this study was the 30-day adverse outcome rate of stroke, myocardial infarction, and/or death. Periprocedural stroke was identified by clinical symptoms and radiographic findings. Secondary endpoints included device and procedural success, 30-day mortality, 30-day stroke rate, and postoperative complications. RESULTS: The authors analyzed the first 62 patients with > 50% symptomatic carotid artery stenosis who underwent TCAR at their institution. The mean age of the cohort was 71.5 years, and the cohort was predominantly male (67.7%). The most common high-risk medical criteria were age older than 75 years (45.3%) and severe coronary artery disease (13.6%). The most common anatomical high-risk criteria were high bifurcation (35.1%) and contralateral stenosis requiring treatment within 30 days (15.8%). Fifty percent of patients had at least 1 medical high-risk criterion, 50% had at least 1 anatomical risk criterion, and 82% of patients had 2 or more high-risk criteria of any kind. Among this group, all patients (100%) underwent successful revascularization, with 1 (1.6%) requiring intraprocedural conversion to carotid endarterectomy. Postprocedurally, there was 1 nondisabling stroke (1.6%) and 3 deaths (4.8%) within 30 days of the procedure, with only 1 death directly attributable to the procedure. One patient (1.6%) experienced a neck hematoma. In total, 4 patients (6.5%) experienced a major complication. The overall complication rate was 8.0%. CONCLUSIONS: The authors' initial experience with TCAR suggests that it might provide an effective alternative to carotid endarterectomy and carotid artery stenting in the management of symptomatic carotid stenosis in patients with high-risk anatomical and medical characteristics.

Incidence, Characteristics, and Outcomes of Pseudomeningocele and Cerebrospinal Fluid Fistula after Posterior Fossa Surgery.

OBJECTIVE: Posterior fossa approaches are common neurosurgical procedures. Rates of postoperative infection, pseudomeningocele, and cerebrospinal fluid (CSF) fistula are high; however, evidence regarding predisposing risk factors and treatment outcomes remain sparse. METHODS: A retrospective cohort study was carried out of all posterior fossa surgeries conducted at a single institution between January 2015 and October 2019. Univariate statistical methods and stepwise logistic regression were used to assess which factors contributed most to risk of development of postoperative complications. RESULTS: A total of 269 patients were included; 18.6% experienced any postoperative complication, 13% developed either pseudomeningocele or CSF fistula, and 9.7% developed an infection. In multivariate analysis, development of a pseudomeningocele was significantly associated with previous cranial surgery (hazard ratio [HR], 3.15; 95% confidence interval [CI], 1.12-9.28; P = 0.0391). Development of a CSF fistula was significantly associated with index surgery for resection of neoplasm (HR, 7.65; 95% CI, 1.86-22.31; P = 0.0174). Development of an infection was significantly associated with concurrent CSF fistula (HR, 7.16; 95% CI, 1.91-23.19; P = 0.0041) and concurrent pseudomeningocele (HR, 3.41; 95% CI, 1.37-5.95; P = 0.0082) and nonsignificantly associated with diabetes requiring treatment (HR, 2.42; 95% CI, 0.69-8.50; P = 0.168). Other hypothesized risk factors for these complications, such as nonmidline approaches to the posterior fossa, watertight duraplasty, use of dural fibrin sealant, and cranioplasty were not associated with these complications on multivariate analysis. Although many patients with pseudomeningocele were successfully managed with observation, only 38% of patients in whom CSF diversion was attempted avoided surgery. CONCLUSIONS: History of diabetes, cranioplasty, revision surgery, and surgery for tumor resection are identified as risk factors for the development of infection, pseudomeningocele, and CSF fistula, respectively.

Compromised Cranio-Spinal Suspension in Chiari Malformation Type 1: A Potential Role as Secondary Pathophysiology.

In Chiari Malformation Type I (CM1), low-lying tonsils obstruct the cisterna magna at the foramen magnum, thereby compromising the essential juncture between the cranial and spinal compartments. The anatomical obstruction of the cisterna magna inhibits bi-directional CSF flow as well as CSF pulse pressure equilibration between the intracranial compartment and the intraspinal compartment in response to instances of increased intracranial pressure. Less understood, however, are the roles of the spinal cord suspension structures at the craniocervical junction which lend viscoelastic support to the spinal cord and tonsils, as well as maintain the anatomical integrity of the cisterna magna and the dura. These include extradural ligaments including the myodural bridges (MDBs), as well as intradural dentate ligaments and the arachnoid framework. We propose that when these elements are disrupted by the cisterna magna obstruction, tonsillar pathology, and altered CSF dynamics, there may arise a secondary pathophysiology of compromised and dysfunctional cranio-spinal suspension in CM1. We present intraoperative images and videos captured during surgical exposure of the craniocervical junction in CM1 to illustrate this proposal.

Safety of Sheathless Transradial Balloon Guide Catheter Placement for Acute Stroke Thrombectomy.

BACKGROUND: Transradial access has been described for mechanical thrombectomy in acute stroke, and proximal balloon occlusion has been shown to improve recanalization and outcomes. However, sheathed access requires a larger total catheter diameter at the access site. We aimed to characterize the safety of sheathless transradial balloon guide catheter use in acute stroke intervention. METHODS: Consecutive patients who underwent sheathless right-sided transradial access for thrombectomy with a balloon guide catheter were identified in a prospectively collected dataset from 2019 to 2021. Demographics, procedure details, and short-term outcomes were collected and reported with descriptive statistics. RESULTS: A total of 48 patients (20 women) with a mean age of 72.3 years were identified. Of patients, 56.3% had occlusions in the left-sided circulation; 35 (72.9%) had M1 occlusions, 7 (14.6%) had M2 occlusions, and 6 (12.5%) had internal carotid artery occlusions. Tissue plasminogen activator was administered to 16 (33.3%) patients. Five (10.4%) patients underwent intraprocedural carotid stenting. The cohort had successful reperfusion after a median of 1 (interquartile range: 1, 2) pass. Median time from access to recanalization was 31 (interquartile range: 25, 53) minutes. A postprocedural Thrombolysis In Cerebral Infarction score of ≥2b was achieved in 46 (95.8%) patients. Five patients had wrist access site hematomas. All hematomas resolved with warm compresses, and no further intervention was required. CONCLUSIONS: Sheathless radial access using a balloon guide catheter may be safely performed for acute ischemic stroke with excellent radiographic outcomes. Further investigation is warranted to evaluate the comparative effectiveness of sheathless compared with sheathed transradial balloon guide access.

Early Outcomes After Carotid Endarterectomy and Carotid Artery Stenting: A Propensity-Matched Cohort Analysis.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) represent options to treat many patients with carotid stenosis. Although randomized trial data are plentiful, estimated rates of morbidity and mortality for both CEA and CAS have varied substantially. OBJECTIVE: To evaluate rates of adverse outcomes after CAS and CEA in a large national database. METHODS: We analyzed 84 191 adult patients undergoing elective, nonemergent CAS (n = 81 361) or CEA (n = 2830), from 2011 to 2018, in the American College of Surgeons' National Surgical Quality Improvement Program database. Odds of adverse outcomes (30-d rates of stroke, myocardial infarction (MI), cardiac arrest, prolonged length of stay (LOS), readmission, reoperation, and mortality) were evaluated in propensity-matched (n = 2821) cohorts through logistic regression. RESULTS: In the propensity-matched cohorts, CAS had increased odds of periprocedural stroke (odds ratio [OR] 1.97, 95% CI 1.32-2.95) and decreased odds of cardiac arrest (OR 0.33, 95% CI 0.13-0.84) and 30-d reoperation (OR 0.59, 95% CI 0.44-0.80) compared to CEA. Relative odds of MI, prolonged LOS, discharge to destination other than home, 30-d readmission, or 30-d mortality were statistically similar. In the unmatched patient population, rates of adverse outcomes with CEA were constant over time; however, for CAS, rates of stroke increased over time. In both the matched and unmatched patient cohorts, patients 70 yr and older had lower rates of post-procedural stroke with CEA, but not with CAS, compared to younger patients. CONCLUSION: In a propensity-matched analysis of a large, prospectively collected, national, surgical database, CAS was associated with increased odds of periprocedural stroke, which increased over time. Rates of MI and death were not significantly different between the 2 procedures.

Revisiting the Resolution of Chiari Malformation in Nonsyndromic Craniosynostosis: A Case of Posterior Cranial Vault Reconstruction in Secondary Pan-Suture Synostosis.

BACKGROUND: While commonly seen in syndromic craniosynostosis, the incidence of Chiari malformation (CM) in nonsyndromic craniosynostosis has been reported at 5% and there is a lack of understanding of the pathophysiology and management of CM in this patient population. CASE DESCRIPTION: We present a 5-year-old male patient who underwent a sagittal craniosynostosis repair at the age of 5 months and returned at the age of 5 years with daily headaches associated with behavioral changes. He was found to have pan-synostoses and radiographic evidence of increased intracranial pressure, including a Chiari malformation. Neurologic and genetic workup was unremarkable. A cranial vault reconstruction was performed, and subsequent imaging demonstrated resolution of previously noted Chiari malformation. CONCLUSIONS: In our case, we provided a unique window into the underlying pathophysiology for CM in patients with concurrent nonsyndromic craniosynostosis that we hope will add to the current foundation of literature supporting the intricate relation between cranial vault compliance and Chiari malformation or hindbrain herniation. Furthermore, we provide insight into the management of acquired CM and support isolated cranial vault reconstruction in those who do not appear to have symptomatic suboccipital compression.

Current management of pediatric chiari type 1 malformations.

OBJECTIVES: Pediatric Chiari Type 1 Malformations (CM1) are commonly referred for neurosurgical opinion. The ideal management in children regarding surgical and radiographic decision making is not clearly delineated. PATIENTS AND METHODS: We retrospectively reviewed our cohort of patients age 18 years and younger referred to a single neurosurgeon for CM1. Baseline MRIs of the spine were obtained. Non-operative patients had repeat imaging at 6-12 months. Patients who underwent an operation (decompression with/without duraplasty) had repeat imaging at 6 months. RESULTS: One hundred and thirty-two patients with mean age of 10 years met inclusion criteria. All patients had post-operative symptomatic improvement. We identified 26 patients with syrinx, 8 with scoliosis, 3 with hydrocephalus, and one had tethered cord. The average tonsillar descent was 8.1 mm in the non-operative group and 11.9 mm in the operative group. Ninety-five patients were managed conservatively (72%). Thirty-seven were offered surgery (28%), and 33 patients underwent intervention; 21 with duraplasty (64%) and 12 without (36%). CONCLUSIONS: Pediatric patients with CM1 require both clinical and radiographic follow-up. Duraplasty may be performed if decompression fails to relieve symptomatology, but is not always needed. CM1 continues to present a challenge in surgical decision making. Adhering to a treatment paradigm may help alleviate difficult decision-making.