Neurosurgery
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Fluorescence-guided surgery is a rapidly growing field that has produced some of the most important innovations in surgical oncology in the past decade. These intraoperative imaging technologies provide information distinguishing tumor tissue from normal tissue in real time as the surgery proceeds and without disruption of the workflow. Many of these fluorescent tracers target unique molecular or cellular features of tumors, which offers the opportunity for identifying pathology with high precision to help surgeons achieve their primary objective of a maximal safe resection. ⋯ In this review, we provide an "in-text glossary" of the fundamental principles of fluorescence with examples of direct applications to fluorescence-guided brain surgery. We offer a detailed discussion of the various advantages and limitations of the most commonly used intraoperative imaging agents, including 5-aminolevulinic acid, indocyanine green, and fluorescein, with a particular focus on the photophysical properties of these specific agents as they provide a framework through which to understand the new agents that are entering clinical trials. To this end, we conclude with a survey of the fluorescent properties of novel agents that are currently undergoing or will soon enter clinical trials for the intraoperative imaging of brain tumors.
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Pipeline embolization device (PED; Medtronic, Dublin, Ireland) utilization is not limited to the treatment of giant wide-necked aneurysms. It has been expanded to handle small blisters, fusiforms, and dissecting intracranial aneurysms. ⋯ Treatment of DCC aneurysms with PED is technically challenging mainly because of the small caliber and tortuosity of the parent arteries. The results of this study further support the safety of flow diverters in the treatment of various distal aneurysms.
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Myelomeningocele (MM) is a condition that is responsible for considerable morbidity in the pediatric population. A significant proportion of the morbidity related to MM is attributable to hydrocephalus and the surgical management thereof. Postnatal repair remains the most common form of treatment; however, increased rates of prenatal diagnosis, advances in fetal surgery, and a hypothesis that neural injury continues in utero until the MM defect is repaired have led to the development and evaluation of prenatal surgery as a means to improve outcomes in afflicted infants. ⋯ Class I evidence from 1 study and class III evidence from 2 studies suggest that, in comparison to postnatal repair, prenatal surgery for MM reduces the risk of developing shunt-dependent hydrocephalus. Therefore, prenatal repair of MM is recommended for those fetuses who meet specific criteria for prenatal surgery to reduce the risk of developing shunt-dependent hydrocephalus (level I). Differences between prenatal and postnatal repair with respect to the requirement for permanent cerebrospinal fluid diversion should be considered alongside other relevant maternal and fetal factors when deciding upon a preferred method of MM closure. The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-2.
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IDH mutation is an important prognostic factor of diffuse astrocytomas. Although the majority of IDH mutations could be identified by immunohistochemical (IHC) stain for R132H-mutant IDH1, DNA sequencing would be required for IHC negative cases to determine their IDH mutation status. This approach is not cost-effective for tumors with low IDH mutation rates. ⋯ Positive BCAT1 stain could be used to exclude diffuse gliomas with IDH1 codon 132 and IDH2 codon 172 mutations. Selecting cases with negative BCAT1 and R132H-mutant IDH1 staining for DNA sequencing of IDH1/2 genes could improve the cost-effectiveness of detecting IDH mutations particularly in tumors with low IDH mutation rates, and confine the need of 1p/19q assay in IDH-mutant tumors.