Intradural osteogenic sarcoma in the lumbar spine.

To our knowledge, this is the third reported case of spinal intradural osteogenic sarcoma. The two prior reported cases had a history of iophendylate injection whereas this patient did not. Other cases involved the cranial meninges, not the spine. This is the first reported case of intradural osteosarcoma in the absence of iophendylate injection. We report our workup, diagnosis, and treatment. We also include a video demonstrating the intraoperative invasion of tumor and dural erosion.

External validity of the chiari severity index and outcomes among pediatric chiari I patients treated with intra- or extra-Dural decompression.

INTRODUCTION: Chiari malformation type-1 (CM-1) may be treated by intradural (ID) or extradural (ED) posterior fossa decompression, although the optimal approach is debated. The Chiari Severity Index (CSI) is a pre-operative metric to predict patient-defined improvement after CM-1 surgery. In this study, we evaluate the results of ID versus ED decompression and assess the external validity of the CSI. METHODS: We performed a retrospective cohort study of pediatric CM-1 patients undergoing decompression at a single academic children's hospital. Characteristics of headache, syrinx, and myelopathy were collected to derive CSI grade. The primary outcome measure was pre-operative symptom resolution. The proportion of patients with favorable outcome was tabulated for each of the three CSI grades and compared to previously published results. RESULTS: From 2004 to 2014, 189 patients underwent ID (48%) or ED (52%) decompression at the Children's Hospital of Philadelphia (CHOP). Follow-up ranged from 1 to 75 months. Rates of symptom resolution (58-64%) and reoperation (8%) were similar regardless of surgical approach. Although proportions of favorable outcomes differed between the CHOP and Washington University (WU) cohorts, the difference was not related to CSI grade (p = 0.63). Furthermore, there was no difference in the proportion of favorable outcomes between the two cohorts regardless of ID (p = 0.26) or ED approach (p = 0.11). CONCLUSIONS: Equivalent rates of symptom resolution and reoperation following ID and ED decompression support the ED approach as a first-line surgical option for pediatric CM-1 patients. In addition, our findings provide preliminary evidence supporting the generalizability of the CSI and its use in future comparative trials.

Efficacy of lamina terminalis fenestration in reducing shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage: a systematic review. Clinical article.

OBJECT: Chronic hydrocephalus requiring shunt placement is a common complication following aneurysmal subarachnoid hemorrhage (SAH). Controversy exists over whether microsurgical fenestration of the lamina terminalis during aneurysm surgery affords a reduction in the development of shunt-dependent hydrocephalus. To resolve this debate, the authors performed a systematic review and quantitative analysis of the literature to determine the efficacy of lamina terminalis fenestration in reducing aneurysmal SAH-associated shunt-dependent hydrocephalus. METHODS: A MEDLINE (1950-2007) database search was performed using the following keywords, singly and in combination: "ventriculoperitoneal shunt," "hydrocephalus," "subarachnoid hemorrhage," "aneurysm," "fenestration," and "lamina terminalis." Additional studies were manually singled out by scrutinizing references from identified manuscripts, major neurosurgical journals and texts, and personal files. A recent study from the authors' institution was also incorporated into the review. Data from included studies were analyzed using the chi-square analysis and Student t-test. The Cochran-Mantel-Haenszel test was used to compare overall incidence of shunt-dependent hydrocephalus. RESULTS: The literature search revealed 19 studies, but only 11 were included in this review, involving 1973 patients. The fenestrated and nonfenestrated cohorts (combined from the various studies) differed significantly with regard to patient sex, age, and clinical grade as well as aneurysm location (p=0.0065, 0.0028, 0.0003, and 0.017, respectively). The overall incidence of shunt-dependent hydrocephalus in the fenestrated cohort was 10%, as compared with 14% in the nonfenestrated cohort (p=0.089). The relative risk of shunt-dependent hydrocephalus in the fenestrated cohort was 0.88 (95% CI 0.62-1.24). CONCLUSIONS: This systematic review revealed no significant association between lamina terminalis fenestration and a reduced incidence of shunt-dependent hydrocephalus. The interpretation of these results, however, is restricted by unmatched cohort differences as well as other inherent study limitations. Although the overall literature supports lamina terminalis fenestration, a number of authors have questioned the technique's benefits, thus rendering its efficacy in reducing shunt-dependent hydrocephalus unclear. A well-designed, multicenter, randomized controlled trial is needed to definitively address the efficacy of this microsurgical technique.

The role of indirect extracranial-intracranial bypass in the treatment of symptomatic intracranial atheroocclusive disease.

OBJECT: The optimal treatment of medically refractory intracranial atheroocclusive disease remains unclear. The EC-IC Bypass Study Investigators found that patients with internal carotid and middle cerebral artery (ICA and MCA) occlusion received no benefit from direct superficial temporal artery to MCA bypass, and that patients with ICA occlusion and MCA stenosis may have actually fared worse after surgery, perhaps in part due to flow reversal in critical perforator-bearing segments. Although the results of recent investigations have suggested that direct bypass may be beneficial in a subgroup of patients with hemodynamic failure secondary to unilateral ICA occlusion, similar data do not exist for patients with hemodynamic failure from other intracranial stenoocclusive diseases. Indirect bypass via encephaloduroarteriosynangiosis offers a surgical alternative that may avoid rapid flow reversal while providing additional flow to at-risk, distal vascular territories. METHODS: Twelve patients with medically resistant hemodynamic failure from intracranial atheroocclusive disease underwent indirect vascular bypass. Eight patients had ICA occlusion and coexistent MCA stenosis, 1 patient had tandem ICA stenoses and MCA stenosis, 1 patient had tandem ICA and MCA occlusion, 1 patient had ICA and posterior cerebral artery occlusion and an ischemic hemisphere supplied via a proximal superficial temporal artery branch, and 1 patient had poor donor arteries and severe medical comorbidities that precluded the use of general anesthesia. Patient evaluation included clinical assessment of neurological status, CT scanning, MR imaging, digital subtraction angiography, and transcranial Doppler ultrasonography with CO(2) reactivity, or SPECT with acetazolamide challenge. Patient records were reviewed and patients were interviewed for outcome assessment, including transient ischemic attack (TIA), cerebral infarction, change in cerebral perfusion, graft patency, and functional level according to the modified Rankin scale. Kaplan-Meier cumulative failure curves for the primary end point of cerebral infarction were used to compare these patients to a control group of 81 patients derived from the literature who received medical management for severe symptomatic hemodynamic failure. RESULTS: Eleven patients underwent encephaloduroarteriosynangiosis and 1 patient received bur holes with dural and arachnoid incisions; the mean length of follow-up was 51.2 +/- 40.1 months. Five patients had decreased perfusion on follow-up despite graft patency, and 10 patients suffered new infarctions or TIAs during the follow-up period. Five patients (42%) suffered infarctions within 1 year of surgery. A meta-analysis of 4 studies of patients with symptomatic ICA occlusion and severe hemodynamic failure who underwent medical treatment revealed a new infarction rate of 30% in the first year after entry into the study. There was no significant difference between patients with severe hemodynamic failure who underwent surgery and those in the medically treated control group (log-rank test, p = 0.179). CONCLUSIONS: The authors found that indirect bypass does not promote adequate pial collateral artery development and appears to be of limited utility in patients with symptomatic ICA or MCA stenoocclusive disease and secondary hemodynamic failure. Rates of postoperative TIAs or cerebral infarctions after indirect bypass in this patient population do not differ from previous reports in patients who received medical management only.

The efficacy of direct extracranial-intracranial bypass in the treatment of symptomatic hemodynamic failure secondary to athero-occlusive disease: a systematic review.

OBJECTIVE: The 1985 International Extracranial-Intracranial (EC-IC) Bypass Trial failed to show a benefit following surgery in patients with varying degrees of angiographic ICA stenosis. More recent studies using modern technology to identify appropriate candidates, however, have generated promising findings. As a result, controversy exists regarding the role of this technique in the treatment of symptomatic athero-occlusive disease. To this end, we performed a systematic review and quantitative analysis of the literature to determine if a subset of patients with symptomatic hemodynamic failure secondary to athero-occlusive disease may benefit from direct EC-IC bypass. METHODS: We performed a MEDLINE (1985-2007) database search using the following keywords, singly and in combination: EC-IC bypass, hemodynamic failure and misery perfusion. Additional studies were identified manually by scrutinizing references from identified manuscripts, major neurosurgical journals and texts, and personal files. Our literature search divided studies into three categories: natural history of patients with stage I hemodynamic failure (16 studies, 2320 patients), natural history of patients with stage II hemodynamic failure (3 studies 163 patients), and outcomes of patients with hemodynamic failure treated by EC-IC bypass (23 studies 506 patients). RESULTS: Patients with severe stage I and stage II hemodynamic failure are at higher risk of cerebral infarction than those with mild disease (p=.014, OR 1.17-4.08 and p=0.10, OR 0.89-3.63, respectively). Additionally, patients with severe hemodynamic failure respond better to surgery than those with mild disease (p=0.03, OR 0.16-0.92). CONCLUSIONS: Patients with severe hemodynamic failure secondary to athero-occlusive disease appear to benefit from direct EC-IC bypass surgery. As a result, the conclusions of the 1985 International EC-IC Bypass Trial may not be applicable to this subset of patients. A randomized clinical trial involving this patient population is warranted.

Radiographic and clinical predictors of hemodynamic insufficiency in patients with athero-occlusive disease.

INTRODUCTION: Recent studies have shown that patients with increased oxygen extraction fraction (OEF) as measured by positron emission tomography (PET) have a substantially increased risk of stroke as a result of hemodynamic insufficiency. These patients appear to be ideal candidates for extracranial (EC)-intracranial (IC) bypass. The feasibility of this screening protocol, however, is controversial given PET's limited availability and high expense. A better understanding of the clinical factors that identify patients with potential hemodynamic insufficiency would streamline screening and improve cost-efficiency. METHODS: We performed a MEDLINE (1985-2007) database search for studies identifying clinical and radiographic predictors of hemodynamic failure and increased OEF on PET. We used the following key words, singly and in combination: "EC-IC bypass," "hemodynamic failure," and "misery perfusion." Additional studies were identified manually by scrutinizing references from manuscripts, major neurosurgical journals and texts, and personal files. Each study was reviewed for methodology, clinical criteria, and correlation with subsequent PET findings and stroke rates. A consensus was determined regarding the predictive value of each marker. RESULTS: Our literature search revealed 5 clinical and radiographic markers that have been used to identify patients with hemodynamic failure: orthostatic limb shaking, blurry vision on exposure to heat, leptomeningeal and ophthalmic collateral circulation on angiography, watershed infarction, and impaired vasodilatory response to acetazolamide. Orthostatic limb shaking is a rare finding but is predictive of hemodynamic failure and is associated with increased stroke risk. Blurry vision on exposure to heat is not predictive of increased stroke risk. Leptomeningeal and ophthalmic collateral circulation is a sensitive but not specific marker. Watershed infarction is highly sensitive and impaired vasodilatory response to acetazolamide is associated with increased OEF but may not be interchangeable. CONCLUSIONS: Orthostatic limb shaking, watershed infarction, collateral circulation, and impaired vasoreactivity to acetazolamide in patients with athero-occlusive disease may predict hemodynamic failure, increased OEF on PET, and high stroke rates. Recognition of these predictive markers may improve patient selection for surgical intervention, as such individuals appear to benefit from EC-IC bypass.

A comprehensive review of radiosurgery for cerebral arteriovenous malformations: outcomes, predictive factors, and grading scales.

The management of cerebral arteriovenous malformations (AVMs) continues to present a challenge to neurosurgeons. The natural history of this condition, as well as the morbidity and mortality of therapeutic interventions, remains incompletely elucidated. Predictive factors and grading scales in AVM management allow risk-benefit analysis of treatment options and comparison of outcomes. Stereotactic radiosurgery is one of the established treatment modalities for AVMs and is generally used to treat lesions that are high risk for surgical resection. Radiosurgery aims to obliterate AVMs and thus prevent hemorrhage or seizure without any new or worsening of existing symptoms. Lesion characteristics and postsurgical complications differ markedly in patientstreated by radiosurgery versus microsurgery. Radiosurgery-based grading systems account for factors that have been associated with various aspects of radiosurgical outcomes including obliteration, hemorrhage, and postoperative complications, particularly those induced by radiation. The purpose of this paper is to describe the most current predictive factors and grading systems for radiosurgical treatment of cerebral AVMs.