Ventriculoperitoneal shunting with an on-off valve for patients with leptomeningeal metastases and intracranial hypertension.

Background: We report our experience with using a ventriculoperitoneal shunt (VPS) with an on-off valve and in-line Ommaya reservoir for the treatment of hydrocephalus or intracranial hypertension in patients with leptomeningeal disease (LMD). Our goal was to determine whether control of intracranial pressure elevation combined with intrathecal (IT) chemotherapy would extend patient survival. Methods: In this IRB-approved retrospective study, we reviewed 58 cases of adult patients with LMD from solid cancers who received a VPS with a reservoir and an on-off valve at M D Anderson Cancer Center from November 1996 through December 2021. Primary tumors were most often melanoma (n = 19) or breast carcinoma (n = 20). Hydrocephalus was diagnosed by clinical symptoms and findings on magnetic resonance imaging (MRI), and LMD by MRI or cerebrospinal fluid analysis. Differences in overall survival (OS) were assessed with standard statistical techniques. Results: Patients who received a VPS and more than 3 IT chemotherapy sessions survived longer (n = 26; OS time from implantation 11.7 ± 3.6 months) than those who received an occludable shunt but no IT chemotherapy (n = 24; OS time from implantation 2.8 ± 0.7 months, P < .018). Peritoneal seeding appeared after shunt insertion in only two patients (3%). Conclusions: This is the largest series reported to date of patients with LMD who had had shunts with on-off valves placed to relieve symptoms of intracranial hypertension. Use of IT chemotherapy and control of hydrocephalus via such shunts was associated with improved survival.

Anatomical considerations of fascial release in ulnar nerve transposition: a concept revisited.

OBJECT: Surgical transposition of the ulnar nerve to alleviate entrapment may cause otherwise normal structures to become new sources of nerve compression. Recurrent or persistent neuropathy after anterior transposition is commonly attributable to a new distal compression. The authors sought to clarify the anatomical relationship of the ulnar nerve to the common aponeurosis of the humeral head of the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS) muscles following anterior transposition of the nerve. METHODS: The intermuscular septa of the proximal forearm were explored in 26 fresh cadaveric specimens. The fibrous septa and common aponeurotic insertions of the flexor-pronator muscle mass were evaluated in relation to the ulnar nerve, with particular attention to the effect of transposition upon the nerve in this region. RESULTS: An intermuscular aponeurosis associated with the FCU and FDS muscles was present in all specimens. Transposition consistently resulted in angulation of the nerve during elbow flexion when this fascial septum was not released. The proximal site at which the nerve began to traverse this fascial structure was found to be an average of 3.9 cm (SD 0.7 cm) from the medial epicondyle. CONCLUSIONS: The common aponeurosis encountered between the FDS and FCU muscles represents a potential site of posttransposition entrapment, which may account for a subset of failed anterior transpositions. Exploration of this region with release of this structure is recommended to provide an unconstrained distal course for a transposed ulnar nerve.

Neurosurgical tactile discrimination training with haptic-based virtual reality simulation.

OBJECTIVE: To determine if a computer-based simulation with haptic technology can help surgical trainees improve tactile discrimination using surgical instruments. MATERIAL AND METHODS: Twenty junior medical students participated in the study and were randomized into two groups. Subjects in Group A participated in virtual simulation training using the ImmersiveTouch simulator (ImmersiveTouch, Inc., Chicago, IL, USA) that required differentiating the firmness of virtual spheres using tactile and kinesthetic sensation via haptic technology. Subjects in Group B did not undergo any training. With their visual fields obscured, subjects in both groups were then evaluated on their ability to use the suction and bipolar instruments to find six elastothane objects with areas ranging from 1.5 to 3.5 cm2 embedded in a urethane foam brain cavity model while relying on tactile and kinesthetic sensation only. RESULTS: A total of 73.3% of the subjects in Group A (simulation training) were able to find the brain cavity objects in comparison to 53.3% of the subjects in Group B (no training) (P  =  0.0183). There was a statistically significant difference in the total number of Group A subjects able to find smaller brain cavity objects (size ≤ 2.5 cm2) compared to that in Group B (72.5 vs. 40%, P  =  0.0032). On the other hand, no significant difference in the number of subjects able to detect larger objects (size ≧ 3 cm2) was found between Groups A and B (75 vs. 80%, P  =  0.7747). CONCLUSION: Virtual computer-based simulators with integrated haptic technology may improve tactile discrimination required for microsurgical technique.

Virtual reality spine surgery simulation: an empirical study of its usefulness.

OBJECTIVE: This study explores the usefulness of virtual simulation training for learning to place pedicle screws in the lumbar spine. METHODS: Twenty-six senior medical students anonymously participated and were randomized into two groups (A = no simulation; B = simulation). Both groups were given 15 minutes to place two pedicle screws in a sawbones model. Students in Group A underwent traditional visual/verbal instruction whereas students in Group B underwent training on pedicle screw placement in the ImmersiveTouch simulator. The students in both groups then placed two pedicle screws each in a lumbar sawbones models that underwent triplanar thin slice computerized tomography and subsequent analysis based on coronal entry point, axial and sagittal deviations, length error, and pedicle breach. The average number of errors per screw was calculated for each group. Semi-parametric regression analysis for clustered data was used with generalized estimating equations accommodating a negative binomial distribution to determine any statistical difference of significance. RESULTS: A total of 52 pedicle screws were analyzed. The reduction in the average number of errors per screw after a single session of simulation training was 53.7% (P  =  0.0067). The average number of errors per screw in the simulation group was 0.96 versus 2.08 in the non-simulation group. The simulation group outperformed the non-simulation group in all variables measured. The three most benefited measured variables were length error (86.7%), coronal error (71.4%), and pedicle breach (66.7%). CONCLUSIONS: Computer-based simulation appears to be a valuable teaching tool for non-experts in a highly technical procedural task such as pedicle screw placement that involves sequential learning, depth perception, and understanding triplanar anatomy.

Present and future of neurosurgery training and education.

Multiple challenges are faced by educators and trainees. These challenges are multidimensional and pertain to a scenario in which trainees have to become in a short period of time competent technical neurosurgeons, while at the same time conscious of economic and professional factors that will influence their practice. It is the duty of societies and leading educators to come together in developing continental methods of training aimed towards "organised learning". The goal should strictly be the education of our residents, not just the utilisation of their manpower for a number of years.

A novel virtual reality simulation for hemostasis in a brain surgical cavity: perceived utility for visuomotor skills in current and aspiring neurosurgery residents.

OBJECTIVE: To understand the perceived utility of a novel simulator to improve operative skill, eye-hand coordination, and depth perception. METHODS: We used the ImmersiveTouch simulation platform (ImmersiveTouch, Inc., Chicago, Illinois, USA) in two U.S. Accreditation Council for Graduate Medical Education-accredited neurosurgical training programs: the University of Chicago and the University of Texas Medical Branch. A total of 54 trainees participated in the study, which consisted of 14 residents (group A), 20 senior medical students who were neurosurgery candidates (group B), and 20 junior medical students (group C). The participants performed a simulation task that established bipolar hemostasis in a virtual brain cavity and provided qualitative feedback regarding perceived benefits in eye-hand coordination, depth perception, and potential to assist in improving operating skills. RESULTS: The perceived ability of the simulator to positively influence skills judged by the three groups: group A, residents; group B, senior medical students; and group C, junior medical students was, respectively, 86%, 100%, and 100% for eye-hand coordination; 86%, 100%, and 95% for depth perception; and 79%, 100%, and 100% for surgical skills in the operating room. From all groups, 96.2% found the simulation somewhat or very useful to improve eye-hand coordination, and 94% considered it beneficial to improve depth perception and operating room skills. CONCLUSION: This simulation module may be suitable for resident training, as well as for the development of career interest and skill acquisition; however, validation for this type of simulation needs to be further developed.

Sensory and motor skill testing in neurosurgery applicants: a pilot study using a virtual reality haptic neurosurgical simulator.

BACKGROUND: Manual skill is important for surgeons, but current methods to evaluate sensory-motor skills in applicants to a surgical residency are limited. OBJECTIVE: To develop a method of testing sensory-motor skill using objective and reproducible virtual reality simulation. METHODS: We designed a set of tests on a 3-dimensional surgical simulator with head and arm tracking, colocalization, and haptic feedback: (1) "trajectory planning in a simulated vertebra," ie, 3-dimensional memory and orientation; "hemostasis in the brain," ie, motor planning, sequence, timing, and precision; and "choose the softest object," ie, haptic perception. We also derived a weighted combined score for all tasks. RESULTS: Of the 55 consecutive applicants to a neurosurgery residency approached, 46 performed at least 1 task, and 36 performed all tasks. For the trajectory planning task, the distance from target ranged from 3 to 30 mm, with 25 of 36 in the 6- to 18-mm range. In the motor planning test, the duration between cauterization attempts ranged between 5 and 22.5 seconds, peaking at 10 to 12.5 seconds in 15 of 36 participants. In the haptic perception test, linear regression demonstrated increased variability in performance with increasing difficulty of task (R = 0.6281). In all tests, performance followed a roughly bell-shaped curve. The combined weighted score of all tests demonstrated a better bell curve distribution, with scores ranging from 0.275 to 0.71 (mean, 0.47; median, 0.4775; SD, 0.1174). CONCLUSION: Our study represents a first step in the direction of an objective, standard, computer-scored test of motor and haptic ability.

Neurosurgery simulation in residency training: feasibility, cost, and educational benefit.

BACKGROUND: The effort required to introduce simulation in neurosurgery academic programs and the benefits perceived by residents have not been systematically assessed. OBJECTIVE: To create a neurosurgery simulation curriculum encompassing basic and advanced skills, cadaveric dissection, cranial and spine surgery simulation, and endovascular and computerized haptic training. METHODS: A curriculum with 68 core exercises per academic year was distributed in individualized sets of 30 simulations to 6 neurosurgery residents. The total number of procedures completed during the academic year was set to 180. The curriculum includes 79 simulations with physical models, 57 cadaver dissections, and 44 haptic/computerized sessions. Likert-type evaluations regarding self-perceived performance were completed after each exercise. Subject identification was blinded to junior (postgraduate years 1-3) or senior resident (postgraduate years 4-6). Wilcoxon rank testing was used to detect differences within and between groups. RESULTS: One hundred eighty procedures and surveys were analyzed. Junior residents reported proficiency improvements in 82% of simulations performed (P < .001). Senior residents reported improvement in 42.5% of simulations (P < .001). Cadaver simulations accrued the highest reported benefit (71.5%; P < .001), followed by physical simulators (63.8%; P < .001) and haptic/computerized (59.1; P < .001). Initial cost is $341,978.00, with $27,876.36 for annual operational expenses. CONCLUSION: The systematic implementation of a simulation curriculum in a neurosurgery training program is feasible, is favorably regarded, and has a positive impact on trainees of all levels, particularly in junior years. All simulation forms, cadaver, physical, and haptic/computerized, have a role in different stages of learning and should be considered in the development of an educational simulation program.

C4-C5 post-traumatic spondyloptosis with in situ fusion: systematic literature review and case report.

STUDY DESIGN: A case report with systematic review of the literature. OBJECTIVE: To report a case of post-traumatic C4-C5 spondyloptosis without neurological deficit not associated with posterior element fractures and presenting in a delayed fashion with fusion in situ of C4 and C5 vertebral bodies influencing the management strategy. SUMMARY OF BACKGROUND DATA: Traumatic spondyloptosis of the subaxial cervical spine is typically associated with neurological injury. To the best of the author's knowledge, this is the first case of spondyloptosis not associated with fractures of the posterior elements but with locked facets at C4-C5 and fusion in situ, presenting in a delayed fashion with remarkable paucity of symptoms that was managed surgically. METHODS: A 45-year-old male presented 8 months after a motor vehicle collision with radicular arm pain and mild spasticity involving the legs. Cervical radiograph, computed tomographic scan, and magnetic resonance image revealed bilateral locked facets at C4-C5 with spondyloptosis. Fusion had occurred in situ. RESULTS: Traction did not correct alignment and the patient underwent circumferential reduction and fusion and postoperative halo-vest placement. At 6-month follow-up, the patient remained neurologically intact with regression of preoperative symptoms. CONCLUSION: Longstanding post-traumatic spondyloptosis may lead to fusion in situ complicating the surgical management. Insufficient suspicion during workup can lead to the omission of this important diagnosis, further complicating operative intervention. Traction is not useful when in situ fusion has occurred in delayed presentation cases. LEVEL OF EVIDENCE: N/A.

Neurosurgery certification in member societies of the WFNS: global overview.

OBJECTIVE: To determine the complexity and diversity of the neurosurgery certification and recertification process in member societies of the World Federation of Neurosurgical Societies. MATERIAL AND METHODS: A 13-item survey was sent to 88 national and regional societies that are members of the World Federation of Neurosurgical Societies. Variables included in the survey covered a wide range of aspects pertaining to the certification process achieved by cognitive and oral examinations. The data received from 40 responding societies (response rate 45%) were tabulated, and an individual and comparative (global) analysis was performed for all categories, including eligibility and requirements for certification, examination components, use of computer-assisted technology and imaging, performance, validation of foreign degrees, recertification, and maintenance of certification. RESULTS: We present here the global analysis, which is comparative of all participating societies. Although there is high variability in the structure of certification programs worldwide, performance in knowledge-based examinations is similar. Recertification and maintenance of certification are still under development in many societies. CONCLUSION: With the onset of globalization, we anticipate that efforts will be made in the future to obtain homogeneity in the structure of certification, recertification, and in criteria for international reciprocity of postgraduate neurosurgical training. Peer-Review Article.

Neurosurgery certification in member societies of the WFNS: Africa and the Middle East.

BACKGROUND: This study sought to compare objectively the complexity and diversity of the certification process in neurological surgery in member societies of the World Federation of Neurosurgical Societies (WFNS) in the African and Middle Eastern regions. METHODS: This report centers on two geographic regions: Africa and the Middle East. We provide a subgroup analysis based on the responses provided to the 13-item survey sent in Part I of this study. The data received were analyzed, and three Regional Complexity Scores (RCS) were designed. To compare national board experience, eligibility requirements to access the certification process, and the obligatory nature of the examinations, a RCS-Organizational score was created (RCS-O, 20 points maximum). To analyze the complexity of the examination, a RCS-Components was designed (RCS-C, 20 points maximum). The sum of both is presented in a global RCS (RCS-G). In addition, a descriptive summary of the certification process per responding society is also provided. RESULTS: Based on the data provided by our RCS system, the highest RCS-G was obtained by South Africa (19 of 40 points), followed by Egypt (18 of 40 points), countries of the Gulf Neurosurgical Society (16 of 40 points), and the Neurosurgical Society of East and Central Africa (16 of 40 points). CONCLUSIONS: This grading system allows societies to compare their process of certification within their continental region and worldwide, potentially identifying aspects for further improvement or development.

Neurosurgery certification in member societies of the World Federation of Neurosurgical Societies: Asia.

OBJECTIVE: To objectively compare the complexity and diversity of the certification process in neurological surgery in member societies of the World Federation of Neurosurgical Societies. METHODS: This study centers in continental Asia. We provide here an analysis based on the responses provided to a 13-item survey. The data received were analyzed, and three Regional Complexity Scores (RCS) were designed. To compare national board experience, eligibility requirements for access to the certification process, and the obligatory nature of the examinations, an RCS-Organizational score was created (20 points maximum). To analyze the complexity of the examination, an RCS-Components score was designed (20 points maximum). The sum of both is presented in a Global RCS score. Only those countries that responded to the survey and presented nationwide homogeneity in the conduction of neurosurgery examinations could be included within the scoring system. In addition, a descriptive summary of the certification process per responding society is also provided. RESULTS AND CONCLUSION: On the basis of the data provided by our RCS system, the highest global RCS was achieved by South Korea and Malaysia (21/40 points) followed by the joint examination of Singapore and Hong-Kong (FRCS-Ed) (20/40 points), Japan (17/40 points), the Philippines (15/40 points), and Taiwan (13 points). The experience from these leading countries should be of value to all countries within Asia.

Intraoperative magnetic resonance imaging-guided tractography with integrated monopolar subcortical functional mapping for resection of brain tumors. Clinical article.

OBJECT: The object of this study was to describe the utility and safety of using a single probe for combined intraoperative navigation and subcortical mapping in an intraoperative MR (iMR) imaging environment during brain tumor resection. METHODS: The authors retrospectively reviewed those patients who underwent resection in the iMR imaging environment, as well as functional electrophysiological monitoring with continuous motor evoked potential (MEP) and direct subcortical mapping combined with diffusion tensor imaging tractography. RESULTS As a navigational tool the monopolar probe used was safe and accurate. Positive subcortical fiber MEPs were obtained in 10 (83%) of the 12 cases. In 10 patients in whom subcortical MEPs were recorded, the mean stimulus intensity was 10.4 ± 5.2 mA and the mean distance from the probe tip to the corticospinal tract (CST) was 7.4 ± 4.5 mm. There was a trend toward worsening neurological deficits if the distance to the CST was short, and a small minimum stimulation threshold was recorded indicating close proximity of the CST to the resection margins. Gross-total resection (95%-100% tumor removal) was achieved in 11 cases (92%), whereas 1 patient (8%) had at least a 90% tumor resection. At the end of 3 months, 2 patients (17%) had persistent neurological deficits. CONCLUSIONS: The monopolar probe can be safely implemented in an iMR imaging environment both for navigation and stimulation purposes during the resection of intrinsic brain tumors. In this study there was a trend toward worsening neurological deficits if the distance from the probe to the CST was short (< 5 mm) indicating close proximity of the resection cavity to the CST. This technology can be used in the iMR imaging environment as a surgical adjunct to minimize adverse neurological outcomes.

Neurosurgery certification in member societies of the World Federation of Neurosurgical Societies (WFNS). The Americas.

INTRODUCTION: This article aims to objectively compare the complexity and diversity of the certification process in neurologic surgery in member societies of the World Federation of Neurosurgical Societies. METHODS: This study centers on the certification processes in the geographic regions of North, South, and Central America. It presents a subgroup analysis based on the responses provided to a 13-item survey. The data received were analyzed and three Regional Complexity Scores (RCSs) were designed. To compare national board experience, eligibility requirements to access the certification process, and the degree to which exams were obligatory, an RCS-Organizational score was created (RCS-O, 20 points maximum). To analyze the complexity of the examination, an RCS-Components score was designed (RCS-C, 20 points maximum). The sum of both is presented as the Global RCS (RCS-G) score. In addition, a descriptive summary of the certification process for each responding society is also provided. RESULTS: On the basis of the data provided by the RCS system, the United States and Brazil seem to have the most developed certification processes in the American continent (20 points each), followed by Canada (18 points) and Mexico (17 points). CONCLUSION: The experience from these leading countries should be of value and reference to other countries, allowing future improvement within the region. Peer-Review Article.

Neurosurgery certification in member societies of the WFNS: Europe.

OBJECTIVE: To objectively compare the complexity and diversity of the certification process in Neurological Surgery in European member societies of the World Federation of Neurosurgical Societies. MATERIALS AND METHODS: The attention of this study centers on Europe. We provide here a subgroup analysis based on the responses provided to a 13-item survey. The data received were analyzed and three regional complexity scores (RCS) were designed. To compare national board experience as well as eligibility requirements to access the certification process and obligatory nature of the examinations, a RCS Organizational score was created (RCS-O, 20 points maximum). To analyze the complexity of the examination a RCS Components score was designed (RCS-C, 20 points maximum). The sum of both is presented in a Global RCS score (RCS-G). In addition, a descriptive summary of the certification process per responding society is also provided. RESULTS AND CONCLUSIONS: Based on the data provided by our RCS system, the highest RCS-G was obtained by the United Kingdom (19/40 points) followed by European Association of Neurosurgical Societies, Poland, and Sweden (16/40 points each), Portugal (15/40 points), and Switzerland (14/40 points). The experience from these leading countries should be of value to all countries of the European Union.

State-of-the-art management and monitoring of brain edema and intracranial hypertension in fulminant hepatic failure. A proposed algorithm.

AIM: Develop an evidence-based clinical algorithm integrating clinical decision making on intracranial pressure (ICP) monitoring and intracranial hypertension (ICH) management in the setting of fulminant hepatic failure (FHF). MATERIAL AND METHODS: An English-language literature review was conducted using the PubMed database in November 2007. In compiling evidence on current management trends of ICP and FHF, the paired keywords: fulminant hepatic failure and either mannitol, hypertonic saline, hyperventilation, bioartificial liver, hypothermia, indomethacin, thiopental, or propofol were used. In compiling evidence on ICP monitoring in FHF, the terms "intracranial pressure monitoring" and "liver failure" were used. Excluded references were either pertinent to animal research or irrelevant to ICP monitoring and ICH management in the setting of FHF. RESULTS: State-of-the-art management of ICH due to brain edema in FHF includes Class I therapies such as mannitol and hypertonic saline. Bioartificial liver, hypothermia and hyperventilation are supported by Class II evidence. Indomethacin and sedation remain Class III. Monitoring ICP is supported by Class II and III evidence. A clinical algorithm was created based on the existing therapeutic armamentarium and corresponding evidence support.

Neuronavigation-guided endoscopic decompression of superior orbital fissure fracture: case report and literature review.

OBJECTIVE: We present a rare case of an isolated superior orbital fissure fracture resulting from blunt injury to the face and presenting with selective cranial nerve deficits surgically treated with a neuroendoscopic approach. The anatomy of the superior orbital fissure is detailed, and the peculiarities of the surgical approach described. METHOD: A review of the existing literature reveals this is the first reported case of a neuronavigation-assisted endoscopic approach used in the extraction of a superior orbital fracture fragment with good outcome. Current guidelines for an endoscopic approach in orbital trauma are reviewed, and pertinent literature is discussed. CONCLUSION: Neuronavigation-assisted decompression should be considered as an effective means of removing superior orbital fissure fractures.

Simultaneous use of functional tractography, neuronavigation-integrated subcortical white matter stimulation and intraoperative magnetic resonance imaging in glioma surgery: technical note.

The importance of preserving function during glioma surgery cannot be overemphasized. There are a number of techniques utilized including functional MRI, direct electrophysiological monitoring and functional neuronavigation to maximize and safely resect gliomas. The intraoperative MRI is an extremely valuable tool and adds to the neurosurgeon's armamentarium. Combining these technologies will enhance the safety and efficacy of glioma surgery. This is the first report in the literature where we successfully combine both functional neuronavigation and subcortical stimulation, using a single probe to safely resect a recurrent glioblastoma.

Surgical options for ulnar nerve entrapment: an example of individualized decision analysis.

The decision-making process in the diagnosis and treatment of an ulnar nerve entrapment (UNE) at the elbow is presented from the viewpoint of the patient and from that of a physician who in this case, were the same individual. The problems of diagnosis and the selection of the appropriate therapy-conservative or surgical and the choice of a particular surgical approach are discussed in the light of recent evidence-based medicine (EMB) literature.

Infratentorial angioleiomyoma: a new location for a rare neoplastic entity.

Angioleiomyomas are benign neoplasms most often located in the subcutaneous tissue of middle-aged individuals and usually confined to the subcuticular and deep dermal layers of the lower extremities. An intracranial site for this tumor is exceedingly rare, with very few reports documenting locations in the neuraxis. To the authors' knowledge the present case represents the first reported instance of an infratentorial angioleiomyoma. The authors conducted a review of selected English-language papers published since 1960 describing well-documented cases of intracranial vascular leiomyomas, with detailed information on the clinical presentation, radiology, pathology, and particulars of surgical management in each case.