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  • Author or Editor: Daniel M. Prevedello x
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Christopher S. Hong, Daniel M. Prevedello and J. Bradley Elder

OBJECT

Tubular brain retractors may improve access to deep-seated brain lesions while potentially reducing the risks of collateral neurological injury associated with standard microsurgical approaches. Here, microscope-assisted resection of lesions using tubular retractors is assessed to determine if it is superior to endoscope-assisted surgery due to the technological advancements associated with modern tubular ports and surgical microscopes.

METHODS

Following institutional approval of the tubular port, data obtained from the initial 20 patients to undergo transportal resection of deep-seated brain lesions were analyzed in this study. The pathological entities of the resected tissues included metastatic tumors (8 patients), glioma (7), meningioma (1), neurocytoma (1), radiation necrosis (1), primitive neuroectodermal tumor (1), and hemangioblastoma (1). Surgery incorporated endoscopic (5 patients) or microscopic (15) assistance. The locations included the basal ganglia (11 patients), cerebellum (4), frontal lobe (2), temporal lobe (2), and parietal lobe (1). Cases were reviewed for neurological outcomes, extent of resection (EOR), and complications. Technical data for the port, surgical microscope, and endoscope were analyzed.

RESULTS

EOR was considered total in 14 (70%), near total (> 95%) in 4 (20%), and subtotal (< 90%) in 2 (10%) of 20 patients. Incomplete resection was associated with the basal ganglia location (p < 0.05) and use of the endoscope (p < 0.002). Four of 5 (80%) endoscope-assisted cases were near-total (2) or subtotal (2) resection. Histopathological diagnosis, presenting neurological symptoms, and demographics were not associated with EOR. Complication rates were low and similar between groups.

CONCLUSIONS

Initial experience with tubular retractors favors use of the microscope rather than the endoscope due to a wider and 3D field of view. Improved microscope optics and tubular retractor design allows for binocular vision with improved lighting for the resection of deep-seated brain lesions.

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Amin B. Kassam, Johnathan A. Engh, Arlan H. Mintz and Daniel M. Prevedello

Object

The authors introduce a novel technique of intraparenchymal brain tumor resection using a rod lens endoscope and parallel instrumentation via a transparent conduit.

Methods

Over a 4-year period, 21 patients underwent completely endoscopic removal of a subcortical brain lesion by means of a transparent conduit. Image guidance was used to direct the cannulation and resection of all lesions. Postoperative MR imaging or CT was performed to assess for residual tumor in all patients, and all patients were followed up postoperatively to assess for new neurological deficits or other surgical complications.

Results

The histopathological findings were as follows: 12 metastases, 5 glioblastomas, 3 cavernous malformations, and 1 hemangioblastoma. Total radiographically confirmed resection was achieved in 8 cases, near-total in 6 cases, and subtotal in 7 cases. There were no perioperative deaths. Complications included 1 infection and 1 pulmonary embolus. There were no postoperative hematomas, no postoperative seizures, and no worsened neurological deficits in the immediate postoperative period.

Conclusions

Fully endoscopic resection may be a technically feasible method of resection for selected subcortical masses. Further experience with this technique will help to determine its applicability and safety.

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Relevance of high Ki-67 in pituitary adenomas

Case report and review of the literature

Daniel M. Prevedello, Jay Jagannathan, John A. Jane Jr., M. Beatriz S. Lopes and Edward R. Laws Jr.

Pituitary adenomas are heterogeneous in growth rate, invasiveness, and recurrence. To understand the biological behavior of the individual adenoma more fully, cell proliferation markers such as monoclonal antibodies targeted against the Ki-67 antigen have been applied. The Ki-67 antigen is a protein related to cell proliferation and is expressed in cell nuclei throughout the entire cell cycle. The authors report the case of an extremely rapidly growing pituitary adenoma with cavernous sinus invasion. The lesion, which displayed a high Ki-67 labeling index (LI; 22%), was found in a 54-year-old woman who presented with diplopia and headaches. The patient underwent three transsphenoidal operations in less than 6 months and, ultimately, was treated with fractionated intensity-modulated radiation therapy. The relationships between high Ki-67 LIs and tumor recurrence, invasiveness, and growth velocity in pituitary adenomas are reviewed.

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Francesco Doglietto, Daniel M. Prevedello, John A. Jane Jr., Joseph Han and Edward R. Laws Jr.

Since its inception, one of the major issues in transsphenoidal surgery has been the adequate visualization of anatomical structures. As transsphenoidal surgery evolved, technical advancements improved the surgical view of the operative field and the orientation. The operating microscope replaced Cushing's headlight and Dott's lighted speculum retractor, and fluoroscopy provided intraoperative imaging. These advances led to the modern concept of micro-surgical transsphenoidal procedures in the early 1970s.

For the past 30 years the endoscope has been used for the treatment of diseases of the sinus and, more recently, in the surgical treatment of pituitary tumors. The collaboration between neurological and otorhinolaryngological surgeons has led to the development of novel surgical procedures for the treatment of various pathological conditions in the skull base.

In this paper the authors review the history of the endoscope—its technical development and its application—from the first endoscope described by Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery held in 2005 in Pittsburgh, Pennsylvania. Specifically, in this review the history of endoscopy and its application in endonasal neurosurgery are presented.

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Jose M. Pascual

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Jay Jagannathan, Aaron S. Dumont, Daniel M. Prevedello, Christopher I. Shaffrey and John A. Jane Jr.

✓Sports-related injuries to the spine, although relatively rare compared with head injuries, contribute to significant morbidity and mortality in children. The reported incidence of traumatic cervical spine injury in pediatric athletes varies, and most studies are limited because of the low prevalence of injury. The anatomical and biomechanical differences between the immature spine of pediatric patients and the mature spine of adults that make pediatric patients more susceptible to injury include a greater mobility of the spine due to ligamentous laxity, shallow angulations of facet joints, immature development of neck musculature, and incomplete ossification of the vertebrae. As a result of these differences, 60 to 80% of all pediatric vertebral injuries occur in the cervical region. Understanding pediatric injury biomechanics in the cervical spine is important to the neurosurgeon, because coaches, parents, and athletes who place themselves in positions known to be associated with spinal cord injury (SCI) run a higher risk of such injury and paralysis. The mechanisms of SCI can be broadly subclassified into five types: axial loading, dislocation, lateral bending, rotation, and hyperflexion/hyperextension, although severe injuries often result from a combination of more than one of these subtypes. The aim of this review was to detail the characteristics and management of pediatric cervical spine injury.

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Liangxue Zhou and Chao You

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Jay Jagannathan, Daniel M. Prevedello, Vivek S. Ayer, Aaron S. Dumont, John A. Jane Jr. and Edward R. Laws

Object

In this study the authors address the efficacy and safety of frameless stereotaxy in transsphenoidal surgery.

Methods

One thousand transsphenoidal operations were performed at the authors' institution between June 2000 and July 2005. This series consists of a retrospective review of 176 patients entered in a prospectively obtained database who underwent frameless stereotactic transsphenoidal surgery in which magnetic resonance (MR) imaging, computerized tomography (CT) scanning, or fluoroscopic guidance was used. Of the 176 patients, 104 (59%) had suprasellar extension of their tumor, 70 (40%) had involvement of the visual apparatus, and 65 (37%) had cavernous sinus involvement. All patients underwent detailed pre- and postoperative neurological, endocrinological, radiographic, and ophthalmological follow-up evaluations. Records were reviewed retrospectively for intraoperative and postoperative complications related to the surgical approach.

No instances of visual deterioration, carotid artery (CA) stenosis, or stroke were observed following transsphenoidal surgery. Only one patient sustained damage to the CA intraoperatively, and this was controlled in the operating room. Five patients (3%) required an intensive care unit stay postoperatively. Intraoperative cerebrospinal fluid leakage was encountered in 112 patients (64%) and was more frequently observed in tumors with suprasellar involvement.

Conclusions

Frameless stereotaxy is a safe and effective modality for the treatment of recurrent or invasive sellar masses. All three frameless stereotaxy modalities provided accurate information regarding the anatomical midline and the trajectory to the sella turcica. The MR imaging, CT scanning, and fluoroscopic stereotaxy modalities all have unique advantages as well as specific limitations.