Journal of neurosurgery
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Journal of neurosurgery · Jan 2015
Brainstem arteriovenous malformations: anatomical subtypes, assessment of "occlusion in situ" technique, and microsurgical results.
The surgical management of brainstem arteriovenous malformations (AVMs) might benefit from the definition of anatomical subtypes and refinements of resection techniques. Many brainstem AVMs sit extrinsically on pia mater rather than intrinsically in the parenchyma, allowing treatment by occluding feeding arteries circumferentially, interrupting draining veins after arteriovenous shunting is eliminated, and leaving the obliterated nidus behind. The authors report here the largest series of brainstem AVMs to define 6 subtypes, assess this "occlusion in situ" technique, and analyze the microsurgical results. ⋯ Brainstem AVMs can be differentiated by their location in the brainstem (midbrain, pons, or medulla) and the surface on which they are based (anterior, posterior, or lateral). Anatomical subtypes can help the neurosurgeon determine how to advise patients, with lateral subtypes being a favorable surgical indication along with extrinsic pial location and hemorrhagic presentation. Most AVMs are dissected with the intention to resect them, and occlusion in situ is reserved for those AVMs that do not separate cleanly from the brainstem, that penetrate into the parenchyma, or are more anterior in location, where it is difficult to visualize and preserve perforating arteries (anterior pontine and lateral medullary AVMs). Although surgical morbidity is considerable, surgery results in a better obliteration rate than nonoperative management and is indicated in highly selected patients with high rerupture risks.
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Journal of neurosurgery · Jan 2015
Intracranial inertial cavitation threshold and thermal ablation lesion creation using MRI-guided 220-kHz focused ultrasound surgery: preclinical investigation.
In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. ⋯ This work demonstrates that 220-kHz ultrasound is capable of inducing a thermal lesion in the brain of living swines without hemorrhage. Although the same acoustic energy can induce either a hemorrhage or a thermal lesion, it seems that low-power, long-duration sonication is less likely to cause hemorrhage and may be safer. Although further study is needed to decrease the likelihood of ischemic infarction associated with the 220-kHz ultrasound, the threshold established in this work may allow for the detection and prevention of deleterious cavitations.
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Journal of neurosurgery · Jan 2015
Neurological outcomes following intraprocedural rerupture during coil embolization of ruptured intracranial aneurysms.
Intraprocedural rerupture (IPR) of intracranial aneurysms during coil embolization is associated with significant periprocedural disability and death. However, whether this morbidity and mortality are secondary to an increased risk of vasospasm and hydrocephalus is unknown. The authors undertook this study to determine the in-hospital and long-term neurological outcomes for patients with aneurysmal subarachnoid hemorrhage (SAH) treated with coil embolization who suffer aneurysm rerupture during treatment. ⋯ Intraprocedural rerupture during coil embolization for ruptured intracranial aneurysms is associated with an increased risk of symptomatic vasospasm and need for temporary and permanent cerebrospinal fluid diversion for hydrocephalus.
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Journal of neurosurgery · Jan 2015
Neuroendoscopic biopsy of brain lesions: accuracy and complications.
The authors conducted a study to analyze the accuracy of neuroendoscopic biopsies of ventricular and periventricular lesions and record any difficulties or complications of the neuroendoscopic biopsy procedure. ⋯ Endoscopic biopsy seems to be an accurate procedure with acceptable morbidity and mortality rates.
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Journal of neurosurgery · Jan 2015
Intraoperative stereotactic injection of Indigo Carmine dye to mark ill-defined tumor margins: a prospective phase I-II study.
A critical goal in neurosurgical oncology is maximizing the extent of tumor resection while minimizing the risk to normal white matter tracts. Frameless stereotaxy and white matter mapping are indispensable tools in this effort, but deep tumor margins may not be accurately defined because of the "brain shift" at the end of the operation. The authors investigated the safety and efficacy of a technique for marking the deep margins of intraaxial tumors with stereotactic injection of Indigo Carmine dye. ⋯ Stereotactic injection of Indigo Carmine dye can be used to demarcate multiple deep tumor margins, which can be readily identified intraoperatively by using standard white light microscopy. This technique may enhance the accuracy of frameless stereotactic navigation and increase the extent of resection of intraaxial tumors.