Journal of neurosurgery
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Journal of neurosurgery · May 2015
Accuracy of direct magnetic resonance imaging-guided placement of drug infusion cannulae.
An intraoperative MRI (iMRI)-compatible system has been developed for direct placement of convection-enhanced delivery (CED) cannulae using real-time imaging. To establish the precision and feasibility of this technology, the authors analyzed findings in patients who underwent direct iMRI CED cannula placement. Three consecutive patients underwent iMRI-guided placement of CED infusion cannulae (6 cannulae) for treatment of diffuse intrinsic brainstem glioma (2 patients) or Parkinson's disease (1 patient). ⋯ There was no correlation between the length of the planned trajectory and any of the measured errors. No complications were associated with cannula placement. Real-time iMRI-based targeting and monitoring of infusion cannula placement is a safe, effective, and accurate technique that should enable more selective perfusion of brain regions.
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Journal of neurosurgery · May 2015
Changes in cerebrospinal fluid flow assessed using intraoperative MRI during posterior fossa decompression for Chiari malformation.
OBJECT The authors completed a prospective, institutional review board-approved study using intraoperative MRI (iMRI) in patients undergoing posterior fossa decompression (PFD) for Chiari I malformation. The purpose of the study was to examine the utility of iMRI in determining when an adequate decompression had been performed. METHODS Patients with symptomatic Chiari I malformations with imaging findings of obstruction of the CSF space at the foramen magnum, with or without syringomyelia, were considered candidates for surgery. ⋯ CONCLUSIONS The authors observed significant CSF flow changes when simply positioning the patient for surgery. These results put into question intraoperative flow assessments that suggest adequate decompression by PFD, whether by iMRI or intraoperative ultrasound. The use of intraoperative imaging during PFD for Chiari I malformation, whether by ultrasound or iMRI, is limited by CSF flow dynamics across the foramen magnum that change significantly when the patient is positioned for surgery.
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World Health Organization Grade 2 meningiomas are aggressive tumors associated with a high recurrence rate leading to repeated surgical procedures, which can seriously worsen a patient's neurological status. Although radiosurgery is an increasingly popular technique, its role in the management of Grade 2 meningiomas has yet to be defined. In this study the authors aimed to evaluate radiosurgery in achieving control of proven tumor progression occurring after resection of Grade 2 meningioma. ⋯ Radiosurgery appears to be a safe and effective treatment for the local control of delayed progression after resection of a Grade 2 meningioma. Higher radiation doses similar to those applied for malignant tumors should be recommended when possible.
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Journal of neurosurgery · May 2015
The human area postrema: clear-cut silhouette and variations shown in vivo.
OBJECT The human area postrema (AP) is a circumventricular organ that has only been described in cadaveric specimens and animals. Because of its position in the calamus scriptorius and the absence of surface markers on the floor of the fourth ventricle, the AP cannot be clearly localized during surgical procedures. METHODS The authors intravenously administered 500 mg fluorescein sodium to 25 patients during neuroendoscopic procedures; in 12 of these patients they explored the fourth ventricle. ⋯ A better understanding of the AP can also be valuable for neurologists, considering its functional role in the regulation of homeostasis, emesis, and cardiovascular and electrolyte balance. Despite the limited number of cases in this report, evidence indicates that the normal anatomical appearance of the AP is that of 2 short and thick leaves that are joined at the midline. However, there can be great variability in terms of the structure's shape and size.
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Journal of neurosurgery · May 2015
Clinical factors associated with venous thromboembolism risk in patients undergoing craniotomy.
OBJECT Patients undergoing craniotomy are at risk for developing venous thromboembolism (VTE). The safety of anticoagulation in these patients is not clear. The authors sought to identify risk factors predictive of VTE in patients undergoing craniotomy. ⋯ Increasing score was predictive of increased VTE incidence, as well as risk of mortality, and time from surgery to discharge. CONCLUSIONS Patients undergoing craniotomy are at low risk of developing VTE, but this risk is increased by preoperative medical comorbidities and postoperative complications. The presence of more of these clinical factors is associated with progressively increased VTE risk; patients possessing a VTE Risk Score of ≥ 5 had a greater than 20-fold increased risk of VTE compared with patients with a VTE score of 0.