bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogel-coated coils for the treatment of cerebral aneurysms: preliminary results
Authors: Arthur Adam S. , Wilson Stephanie A. , Dixit Sanat , Barr John D. 
Published: January 2008

Object
The authors present a retrospective analysis of their initial experience with the recently developed MicroVention HydroCoil to treat patients with cerebral aneurysms. Unlike the bare metal coils initially available for endovascular treatment of aneurysms, HydroCoils have a layer of hydrogel polymer surrounding a platinum metallic core. The hydrogel polymer expands soon after making contact with blood. The expanded hydrogel polymer provides increased volumetric filling compared with bare metal coils and offers a more biocompatible surface, as demonstrated in animal models.

Methods
Over a 17-month period, the authors used HydroCoils to treat 30 patients with 33 aneurysms. All patients had been treated at least 6 months prior to data analysis. Initial treatment results as well as records of clinical and angiographic follow up were reviewed. Six-month posttreatment angiograms were available for 25 patients.

Conclusions
The HydroCoils were implanted with few complications. On angiographic follow up, a clearly defined radiolucent separation of the coils from the parent artery was noted in many of the aneurysms treated. The authors have not previously observed angiographically demonstrated lucencies separating the coils from the parent artery. This frequent, but not consistent, appearance on follow-up angiograms obtained in this study indicates that HydroCoils support significant neointimal formation across the neck of treated aneurysms. The preliminary results indicate that HydroCoils can be used safely and effectively to treat aneurysms and that these devices may allow for improved aneurysm filling.
Endovascular management of intracranial vertebral artery dissecting aneurysms
Authors: Albuquerque Felipe C. , Fiorella David J. , Han Patrick P. , Deshmukh Vivek R. , Kim Louis J. , Mcdougall Cameron G. 
Published: January 2008

Object
Intracranial vertebral artery (VA) dissecting aneurysms often present with severe subarachnoid hemorrhage (SAH) and dramatic neurological injury. The authors reviewed the management of 23 cases in an effort to evaluate treatment efficacy and outcomes.

Methods
The records of 23 patients who underwent endovascular treatment were reviewed to determine symptoms, type of therapy, complications, and clinical outcomes. All patients were evaluated using records kept in a prospectively maintained database.
Ten men and 13 women (age range 35–72 years; mean age 49 years) were treated over an 8-year period. Twelve patients presented with poor-grade SAH, five with good-grade SAH, three with headache, and two with stroke. The other patient's aneurysm was discovered incidentally. Treatment included coil occlusion of the artery at the aneurysm in 21 patients and stent-assisted coil placement in two. Parent artery sacrifice was successful in all cases, whereas both patients treated with stent-assisted coil insertion suffered recurrences. No patient sustained permanent complications as a result of treatment. Two patients died due to the severity of their original SAH. Findings were normal in 14 patients on follow-up review (including five of the 12 presenting with poor-grade SAH), five had fixed neurological deficits but were able to care for themselves, and one was permanently disabled.

Conclusions
Despite their often aggressive neurological presentation, intracranial VA dissecting aneurysms can be managed safely with coil occlusion of the lesion and/or parent artery. Even patients presenting in poor neurological condition may improve dramatically.
Decreases in the number and severity of morphometrically defined vertebral body deformities after kyphoplasty
Authors: Ledlie Jon T. , Renfro Mark B. 
Published: January 2008

Object
Vertebral body (VB) deformities have been associated with increased patient morbidity and mortality rates. The aim of this retrospective, consecutive single-center cohort study was to determine the effectiveness of kyphoplasty in reducing morphometrically defined VB deformity, including deformity shape types (wedge, biconcave, or crush) and grade (severity).

Methods
The authors identified 100 patients (70% women; mean age 76.1 years) in whom 138 vertebral fractures (T-4 through L-5; mean fracture age 2.7 months) that were treated between May 2000 and December 2001 were radiographically evaluated preoperatively and at the last follow-up visit (mean follow-up duration 16.9 months). Fractures were divided into four groups by level: T5–9 (28 fractures), T10–12 (41), L1–2 (42), and L3–5 (27). Anterior, mid-line, posterior, and predicted posterior vertebral heights for fractured and adjacent unfractured reference vertebrae were measured on lateral radiographs. The deformity type and grade were mathematically defined using the modified methods of McCloskey–Kanis and Black.
The total number of deformities decreased from 89.9 to 53.6% after kyphoplasty (p < 0.0001). The number of fractures with wedge, biconcave, or crush deformity decreased 22.5, 59.1, and 67.7% (p = 0.0699, p = 0.0222, p = 0.0007), respectively. The number of the more severe Grade 2 deformities decreased (79.7 to 37.0%; p < 0.0001). Kyphoplasty effectively decreased the number of deformed fractures in all vertebral level groups (T5–9, p = 0.0023; T10–12, p = 0.0105; L1–2, p < 0.0001; L3–5, p = 0.0028).

Conclusions
Kyphoplasty resulted in significant normalization of vertebral shapes in patients with symptomatic vertebral fractures, reducing the number and severity of deformed fractures postoperatively.
Immediate and early postoperative pain relief after kyphoplasty without significant restoration of vertebral body height in acute osteoporotic vertebral fractures
Authors: Feltes Carlos , Fountas Kostas N. , Machinis Theofilos , Nikolakakos Leonidas G. , Dimopoulos Vassilios , Davydov Rostislav , Kassam Mozaffar , Johnston Kim W. , Robinson Joe Sam 
Published: January 2008

Object
Painful osteoporotic vertebral compression fractures (VCFs) are a significant cause of disability in the elderly population. Kyphoplasty, a recently developed minimally invasive procedure, has been advocated for the successful management of these fractures in terms of immediate pain relief, and also for restoration of the premorbid level of daily activities. In this retrospective study the authors report on their experience with the early management of VCFs with kyphoplasty.

Methods
A retrospective analysis was conducted in 13 patients (seven women and six men) whose ages ranged from 48 to 87 years (mean age 71.5 ± 11 years [mean ± standard deviation]). The interval between onset of symptoms and surgical intervention ranged from 4 to 9 weeks. Twenty levels (12 thoracic, eight lumbar) were treated in this cohort. Immediate and early postoperative (1-month follow-up visit) visual analog scale (VAS) pain scores, activity levels, and restoration of vertebral body (VB) height were assessed.
The mean preoperative VAS score was 8 ± 1, whereas the immediate and early postoperative scores were 1 ± 1. These findings reflected a resolution of 90 to 100% of preoperative pain. All patients resumed routine activities within hours of the procedure, although improvement in VB height was not accomplished in this cohort. No major complications were encountered in this clinical series.

Conclusions
Kyphoplasty is a safe and effective method for the treatment of osteoporotic VCFs. Failure to restore VB height does not seem to interfere with the excellent pain management and good functional outcome provided by this procedure.
Preliminary results of balloon kyphoplasty for vertebral compression fractures in organ transplant recipients
Authors: Deen H. Gordon , Aranda-Michel Jaime , Reimer Ronald , Putzke John D. 
Published: January 2008

Object
Organ transplant recipients are at risk for vertebral compression fractures (VCFs). The goal of this study was to determine whether kyphoplasty is an effective treatment for VCFs that develop in this patient population.

Methods
Six consecutive patients who had undergone an organ transplant (five liver and one kidney transplant) had a total of 13 symptomatic VCFs that were treated with balloon kyphoplasty. Postprocedure follow-up duration ranged from 6 to 12 months. The mean visual analog scale pain score was 9.3 before treatment and declined to 1.8 after treatment. This improvement was highly significant (p < 0.001). Intake of narcotic drugs decreased or was eliminated in all patients, and there were no complications related to the procedure. There was one instance of clinically insignificant extraosseous cement extravasation. Sagittal alignment was improved by 5° in one patient and was unchanged in the remaining five. During the follow-up period, a new fracture developed adjacent to a treated level in one patient. This was successfully treated with an additional kyphoplasty procedure.

Conclusions
Kyphoplasty can be performed safely in organ transplant recipients with VCF, in whom results are just as favorable as those seen in patients with no history of organ transplantation.
Balloon kyphoplasty for treatment of sacral insufficiency fractures
Authors: Deen H. Gordon , Nottmeier Eric W. 
Published: January 2008

Sacral insufficiency fracture is a painful injury, for which no effective treatment currently exists. The objective of this study was to report on the clinical outcomes and technical aspects of balloon kyphoplasty, which was used in three patients with this injury.
Three elderly women with intractable pain from sacral insufficiency fractures were treated with polymethyl methacrylate (PMMA) injections into the sacrum by using a modified balloon kyphoplasty procedure. The visual analog scale pain score improved by four points in each case. Functional status was improved and analgesic medication requirements were decreased in all three patients. There were no complications associated with the procedure.
Because of the unique anatomy of the sacrum, it was difficult to monitor instrument placement and PMMA injection by using conventional fluoroscopy. BrainLAB image guidance was used in one case, and was helpful in guiding instrument placement and assuring accurate PMMA deposition at the fracture site.
Balloon kyphoplasty may be a treatment alternative in selected patients with sacral insufficiency fractures. BrainLAB image guidance may offer some advantages over conventional fluoroscopy with regard to the monitoring of instrument placement and PMMA injection.
Recurrent or refractory trigeminal neuralgia after microvascular decompression, radiofrequency ablation, or radiosurgery
Authors: Sanchez-Mejia Rene O. , Limbo Mary , Cheng Jason S. , Camara Joaquin , Ward Mariann M. , Barbaro Nicholas M. 
Published: January 2008

Object
Trigeminal neuralgia (TN) is characterized by paroxysmal lancinating pain in the trigeminal nerve distribution. When TN is refractory to medical management, patients are referred for microvascular decompression (MVD), radiofrequency ablation, or radiosurgery. After the initial treatment, patients may have refractory or recurrent symptoms requiring retreatment. The purpose of this study was to determine what factors are associated with the need for retreatment and which modality is most effective.

Methods
To define this population further, the authors evaluated a cohort of patients who required retreatment for TN. The mean follow-up periods were 51 months from the first treatment and 23 months from the last one, and these were comparable among treatment groups.

Conclusions
Trigeminal neuralgia can recur after neurosurgical treatment. In this study the authors demonstrate that the number of patients requiring retreatment is not negligible. Lower retreatment rates were seen in patients who initially underwent radiosurgery, compared with those in whom MVD or radiofrequency ablation were performed. Radiosurgery was more likely to be the final treatment for recurrent TN regardless of the initial treatment. After retreatment, the majority of patients attained complete or very good pain relief. Pain relief after retreatment correlates with postoperative facial numbness.
Management of medically refractory trigeminal neuralgia in patients with multiple sclerosis
Authors: Cheng Jason S. , Sanchez-Mejia Rene O. , Limbo Mary , Ward Mariann M. , Barbaro Nicholas M. 
Published: January 2008

Object
Trigeminal neuralgia (TN) is a painful disorder that frequently causes lancinating, electrical shock–like pain in the trigeminal distribution. Common surgical treatments include microvascular decompression (MVD), radio-surgery, and radiofrequency ablation, and complete pain relief is generally achieved with a single treatment in 70 to 85% of cases for all modalities. In a subset of patients with multiple sclerosis (MS), however, the rates of surgical treatment failure and the need for additional procedures are significantly increased compared with those in patients without MS. In this study the authors report their experience with a cohort of 11 patients with TN who also had MS, and assess the efficacy of MVD, gamma knife surgery (GKS), and radiofrequency ablation in achieving complete or partial long-term pain relief.

Methods
Eleven patients with TN and MS who were treated by the senior author (N.B.) at the University of California, San Francisco were included in this study. All patients underwent GKS and/or radiofrequency ablation, and four received MVD. A detailed clinical history and intraoperative findings were recorded for each patient and frequent follow-up evaluations were performed, with a mean follow-up duration of 40.6 months (range 1–96 months). Pain was assessed for each patient by using the Barrow Neurological Institute scale (Scores I–V).

Conclusions
Achieving complete pain relief in patients with TN and MS required significantly more treatments compared with all other patients with TN who did not have MS (p = 0.004). Even when compared with a group of 32 patients who had highly refractory TN, the cohort with MS required significantly more treatments (p = 0.05). Radiosurgery proved to be an effective procedure and resulted in fewer retreatments and longer pain-free intervals compared with MVD or radiofrequency ablation.
Differentiation of choroid plexus tumors by advanced magnetic resonance spectroscopy
Authors: Krieger Mark D. , Panigrahy Ashok , McComb J. Gordon , Nelson Marvin D. , Liu Xiaodong , Gonzalez-Gomez Ignacio , Gilles Floyd , Bluml Stefan 
Published: January 2008

Object
The management of pediatric intraventricular tumors is highly dependent on identification of the tumor type. Choroid plexus papillomas, a common intraventricular tumor in children, can be difficult to distinguish radiographically from choroid plexus carcinomas and other common pediatric central nervous system (CNS) tumors. In this study to overcome the limitations of current noninvasive imaging modalities, the authors use novel magnetic resonance (MR) spectroscopy techniques in vivo to elucidate the identifying biochemical features of choroid plexus tumors that may facilitate diagnosis and treatment.

Methods
Based on an Internal Review Board–approved protocol, six children with newly diagnosed, untreated intraventricular brain tumors were identified. On retrospective review, this series included three choroid plexus papillomas and three choroid plexus carcinomas. Single-voxel proton MR spectroscopy with a short echo time was performed, and absolute metabolite concentrations (in mmol/kg) were determined using fully automated quantitation. These results were compared with MR spectroscopy profiles obtained in 54 other untreated CNS neoplasms in children.
The myo-inositol (mI) level was significantly higher in choroid plexus papillomas (> 10 mmol/kg), uniquely distinguishing these tumors from choroid plexus carcinomas and all other tumors. Choroid plexus carcinomas, on the other hand, had significantly elevated levels of choline when compared with choroid plexus papillomas.

Conclusions
In this study the authors find that mI is a biochemical constituent that uniquely identifies choroid plexus papillomas and can be used as a noninvasive means of diagnosis and for follow-up evaluations in patients with this disease.
Hemorrhagic sequelae from intracranial neuroendoscopic procedures for intraventricular tumors
Authors: Luther Neal , Cohen Anders , Souweidane Mark M. 
Published: January 2008

Object
Concern regarding the ability to accomplish adequate hemostasis during intracranial neuroendoscopy is often cited as a potential obstacle for primary endoscopic tumor management. In this study, the rate of clinically significant hemorrhage encountered as a result of endoscopic surgery for an intraventricular brain tumor is examined.

Methods
A total of 86 patients underwent an endoscopic biopsy procedure or resection of an intraventricular tumor. Recognized hemorrhagic sequelae occurred at a rate of 3.5% per patient. Visual obscuration due to the presence of intraventricular bleeding necessitated aborting the procedure before completion of the objective in two cases. There was a hemorrhagic event resulting in relevant morbidity in one patient, who suffered a bilateral diencephalic stroke after attempted tumor biopsy sampling.

Conclusions
The low hemorrhagic complication rate described in this series counters the misconception surrounding ineffective hemostasis during intracranial endoscopy for tumors and provides further evidence that this minimally invasive approach is a safe alternative to some conventional intracranial approaches.
Image-guided endoscopy: description of technique and potential applications
Authors: Mayberg Marc R. , LaPresto Eric , Cunningham Edwin J. 
Published: January 2008

Object
Neuroendoscopic approaches to lesions of the central nervous system and spine are limited by the loss of stereoscopic vision and high-fidelity image quality inherent in the operating microscope. Image-guided endoscopy (IGE) and image-guided surgery (IGS) have the potential to overcome these limitations. The goal of this study was to evaluate IGE for its potential applications in neurosurgery.

Methods.
To determine the feasibility of IGE, a rigid endoscope was tracked using an IGS system that provided navigational data for the endoscope tip and trajectory as well as a computer-generated, three-dimensional, virtual representation of the image provided by the endoscope.
The IGE procedure was successfully completed in 14 patients (nine with pituitary adenomas, one with a temporal cavernous malformation, and four with unruptured aneurysms). No complications could be attributed to the procedure. Compared with direct microscopy performed using anatomical landmarks, registration of the endoscope, and virtual image were highly accurate.

Conclusions
This procedure offers many potential advantages for central nervous system and spinal endoscopy. Advances in IGE may enable its application to regions outside the central nervous system as well.
Percutaneous intraspinal navigation for access to the subarachnoid space: use of another natural conduit for neurosurgical procedures
Authors: Purdy Phillip D. , Fujimoto Takuya , Replogle Robert E. , Giles Brian P. , Fujimoto Hitomi , Miller Susan L. 
Published: January 2008

Object
The purpose of this paper was to demonstrate the usefulness of various fiberoptic endoscopes for percutaneous intraspinal navigation of the spinal canal, posterior fossa, and ventricular system.

Methods
Fresh, unembalmed cadavers were used, in which lumbar punctures were made for access to the sub-arachnoid space (in the case of larger [3.8- and 5-mm-diameter] endoscopes, small laminotomies were performed). Static and video images of pertinent structures were acquired for comparison among devices. Endoscopes were compared for their maneuverability, durability, field of view, and image quality. Seven sizes and types of endoscopes were considered.
Overall, the devices offering a tip-deflecting mechanism were superior in maneuverability. Endoscopes in which a charged couple display chip was used at the tip of the scope for image acquisition offered improved image quality and field of view. Larger scopes, although more durable, were more rigid and may be limited in application. Multiple images from multiple devices are presented.

Conclusions
Percutaneous intraspinal navigation offers a promising neurosurgical approach to the spinal canal, the posterior fossa, and the ventricular system. Concerns regarding safety, management of complications, and the lack of adjunctive tools for intervention through the endoscopes or for use under fluoroscopic guidance represent areas that warrant further investigation and development.
Dynamic collimator optimization compared with fixed collimator angle in arc-based stereotactic radiotherapy: a dosimetric analysis
Authors: Lee Christopher M. , Watson Gordon A. , Leavitt Dennis D. 
Published: January 2008

Object
The purpose of this study was to determine the effect of static and dynamic collimator optimization when using a micromultileaf collimator (mMLC) in dynamic-arc stereotactic radiosurgery (SRS) by evaluating the dose to healthy peritumoral tissue.

Methods
Thirty patients previously treated for intracranial lesions with the BrainLAB mMLC underwent retrospective replanning. Three collimator optimization strategies were compared for a simulated SRS treatment plan, as follows: Strategy 1, static collimation fixed at 90° throughout arcs; Strategy 2, static collimator settings optimized for each arc; and Strategy 3, dynamic collimator settings optimized every 10° throughout treatment arcs. Dose–volume histograms for a 0.7-cm shell of healthy peritumoral tissue were quantitatively compared.
Collimator optimization schemes (Strategies 2 and 3) significantly decreased the volume of peritumoral tissue that is irradiated when compared with static collimation at 90° (Strategy 1). The volume was reduced by 40.6% for Strategy 2 (95% confidence interval [CI] ± 11) and by 47.1% for Strategy 3 (95% CI ± 8.1) at the 95% isodose; by 28.4% for Strategy 2 (95% CI ± 4.9) and 39.1% for Strategy 3 (95% CI ± 6) at the 90% isodose; and by 18.2% for Strategy 2 (95% CI ± 8.1) and 25.4% for Strategy 3 (95% CI ± 7.1) at the 80% isodose. Serial collimator optimization throughout the treatment arcs (Strategy 3) reduced the mean volume of peritumoral tissue irradiated when compared with static collimator optimization (Strategy 2), by 16.1% (95% CI ± 1.5) at 95% isodose, by 11.7% (95% CI ± 1) at 90% isodose, and by 8.2% (95% CI ± 1.2) at 80% isodose regions. In specific cases, linear or polynomial functions were formulated to optimize collimator settings dynamically throughout treatment arcs.

Conclusions
Dynamic collimator optimization during arc-based SRS decreases the volume of healthy peritumoral tissue treated with high doses of radiation and appears to be an effective method of improving target conformality. This study is the first step toward determination of a smoothing function algorithm to allow for true dynamic collimation during SRS.