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Background Opioid use disorders in the United States have rapidly increased, yet little is known about the relationship between preoperative opioid duration and dose and patient outcomes after spine surgery. Likewise, the utility of preoperative opioid weaning is poorly understood. Objective The purpose of this evidence-based clinical practice guideline is to determine if duration and dose of preoperative opioids or preoperative opioid weaning is associated with patient-reported outcomes or adverse events after elective spine surgery for degenerative conditions. Methods A systematic review of the literature was performed using the National Library of Medicine/PubMed database and Embase for studies relevant to opioid use among adult patients undergoing spine surgery. Clinical studies evaluating preoperative duration, dose, and opioid weaning and outcomes were selected for review. Results A total of 41 of 845 studies met the inclusion criteria and none were Level I evidence. The use of any opioids before surgery was associated with longer postoperative opioid use, and longer duration of opioid use was associated with worse outcomes, such as higher complications, longer length of stay, higher costs, and increased utilization of resources. There is insufficient evidence to support the efficacy of opioid weaning on postoperative opioid use, improving outcome, or reducing adverse events after spine surgery. Conclusion This evidence-based clinical guideline provides Grade B recommendations that preoperative opioid use and longer duration of preoperative opioid use are associated with chronic postoperative opioid use and worse outcome after spine surgery. Insufficient evidence supports the efficacy of an opioid wean before spine surgery (Grade I).The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/1-preoperative-opioid-evaluation.

Preoperative malnutrition has been implicated in adverse events after elective surgery, potentially impacting patient outcomes.As a potentially modifiable risk factor, we sought to determine which assessments of nutritional status were associated with specific adverse events after spine surgery. In addition, we explored if a preoperative nutritional improvement intervention may be beneficial in lowering the rates of these adverse events.The literature search yielded 115 abstracts relevant to the PICO (patient/population, intervention, comparison, and outcomes) questions included in this chapter. The task force selected 105 articles for full text review, and 13 met criteria for inclusion in this systematic review.Malnutrition, assessed preoperatively by a serum albumin3.5 g/dL or a serum prealbumin20 mg/dL, is associated with a higher rate of surgical site infections (SSIs), other wound complications, nonunions, hospital readmissions, and other medical complications after spine surgery. A multimodal nutrition management protocol decreases albumin and electrolyte deficiencies in patients with normal preoperative nutritional status. It also improves overall complication rates but does not specifically impact SSIs.It is recommended to assess nutritional status using either serum albumin or prealbumin preoperatively in patients undergoing spine surgery.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/4-preoperative-nutritional-assessment.

BACKGROUND Osteoporosis is a metabolic bone disease that commonly affects the elderly. Degenerative spinal disease that may require surgical intervention is also prevalent in this susceptible population. If undiagnosed or untreated before spine surgery, osteoporosis may result in an increased risk of postoperative adverse events. Nontreatment of osteoporosis preoperatively may be related to a poor understanding of bone physiology, a lack of standardized treatment algorithms, limited cost-effective interventions, and reluctance by spine surgeons to be the primary provider of osteoporosis management. OBJECTIVE The objective of this evidence-based review is to develop guidelines for the preoperative assessment and treatment of osteoporosis in patients undergoing spine surgery. METHODS A systematic review of the literature was performed using the National Library of Medicine/PubMed database and Embase for studies relevant to preoperative diagnostic studies that predict increased risk of osteoporosis-related postoperative adverse events and whether the preoperative treatment of low bone mineral density (BMD) in patients with osteoporosis improves outcome. RESULTS Out of 281 studies, 17 met the inclusion criteria and were included for systematic review. The task force affirmed a Grade B recommendation that preoperative osteoporosis testing with a dual-energy X-ray absorptiometry scan (T-score < -2.5), a computed tomography scan (Hounsfield units

Degenerative spine disease increases in prevalence and may become debilitating as people age. Complex spine surgery may offer relief but becomes riskier with age. Efforts to lessen the physiological impact of surgery through minimally invasive techniques and enhanced recovery programs mitigate risk only after the decision for surgery. Frailty assessments outperform traditional tools of perioperative risk stratification. The extent of frailty predicts complications after spine surgery such as reoperation for infection and 30-day mortality, as well as elements of social cost such as hospital length of stay and discharge to an advanced care facility. Symptoms of spine disease overlap with phenotypic markers of frailty; therefore, different frailty assessment tools may perform differently in patients with degenerative spine disease. Beyond frailty, however, cognitive decline and psychosocial isolation may interact with frailty and affect achievable surgical outcomes. Prehabilitation, which has reduced perioperative risk in colorectal and cardiac surgery, may benefit potential complex spine surgery patients. Typical prehabilitation includes physical exercise, nutrition supplementation, and behavioral measures that may offer symptomatic relief even in the absence of surgery. Nonetheless, the data on the efficacy of prehabilitation for spine surgery remains sparse and barriers to prehabilitation are poorly defined. This narrative review concludes that a frailty assessment-potentially supplemented by an assessment of cognition and psychosocial resources-should be part of shared decision-making for patients considering complex spine surgery. Such an assessment may suffice to prompt interventions that form a prehabilitation program. Formal prehabilitation programs will require further study to better define their place in complex spine care.

Expert opinion-modified Delphi study.We used a modified Delphi approach to obtain consensus among leading spinal deformity surgeons and their neuroanesthesiology teams regarding optimal practices for obtaining reliable motor evoked potential (MEP) signals.Intraoperative neurophysiological monitoring of transcranial MEPs provides the best method for assessing spinal cord integrity during complex spinal surgeries. MEPs are affected by pharmacological and physiological parameters. It is the responsibility of the spine surgeon and neuroanesthesia team to understand how they can best maintain high-quality MEP signals throughout surgery. Nevertheless, varying approaches to neuroanesthesia are seen in clinical practice.We identified 19 international expert spinal deformity treatment teams. A modified Delphi process with two rounds of surveying was performed. Greater than 50% agreement on the final statements was considered "agreement";75% agreement was considered "consensus."Anesthesia regimens and protocols were obtained from the expert centers. There was a large amount of variability among centers. Two rounds of consensus surveying were performed, and all centers participated in both rounds of surveying. Consensus was obtained for 12 of 15 statements, and majority agreement was obtained for two of the remaining statements. Total intravenous anesthesia was identified as the preferred method of maintenance, with few centers allowing for low mean alveolar concentration of inhaled anesthetic. Most centers advocated for150 μg/kg/min of propofol with titration to the lowest dose that maintains appropriate anesthesia depth based on awareness monitoring. Use of adjuvant intravenous anesthetics, including ketamine, low-dose dexmedetomidine, and lidocaine, may help to reduce propofol requirements without negatively effecting MEP signals.Spine surgeons and neuroanesthesia teams should be familiar with methods for optimizing MEPs during deformity and complex spinal cases. Although variability in practices exists, there is consensus among international spinal deformity treatment centers regarding best practices.5.

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Background Treatment of thoracolumbar burst fractures has traditionally involved spinal instrumentation with fusion performed with standard open surgical techniques. Novel surgical strategies, including instrumentation without fusion and percutaneous instrumentation alone, have been considered less invasive and more efficient treatments. Objective To review the current literature and determine the role of fusion in instrumented fixation, as well as the role of percutaneous instrumentation, in the treatment of patients with thoracolumbar burst fractures. Methods The task force members identified search terms/parameters and a medical librarian implemented the literature search, consistent with the literature search protocol (see Appendix I), using the National Library of Medicine PubMed database and the Cochrane Library for the period from January 1, 1946 to March 31, 2015. Results A total of 906 articles were identified and 38 were selected for full-text review. Of these articles, 12 articles met criteria for inclusion in this systematic review. Conclusion There is grade A evidence for the omission of fusion in instrumented fixation for thoracolumbar burst fractures. There is grade B evidence that percutaneous instrumentation is as effective as open instrumentation for thoracolumbar burst fractures. Question Does the addition of arthrodesis to instrumented fixation improve outcomes in patients with thoracic and lumbar burst fractures? Recommendation It is recommended that in the surgical treatment of patients with thoracolumbar burst fractures, surgeons should understand that the addition of arthrodesis to instrumented stabilization has not been shown to impact clinical or radiological outcomes, and adds to increased blood loss and operative time. Strength of Recommendation: Grade A. Question How does the use of minimally invasive techniques (including percutaneous instrumentation) affect outcomes in patients undergoing surgery for thoracic and lumbar fractures compared to conventional open techniques? Recommendation Stabilization using both open and percutaneous pedicle screws may be considered in the treatment of thoracolumbar burst fractures as the evidence suggests equivalent clinical outcomes. Strength of Recommendation: Grade B The full version of the guideline can be reviewed at: https://www.cns.org/guideline-chapters/congress-neurological-surgeons-systematic-review-evidence-based-guidelines/chapter_12.

Background Thoracic and lumbar burst fractures in neurologically intact patients are considered to be inherently stable, and responsive to nonsurgical management. There is a lack of consensus regarding the optimal conservative treatment modality. The question remains whether external bracing is necessary vs mobilization without a brace after these injuries. Objective To determine if the use of external bracing improves outcomes compared to no brace for neurologically intact patients with thoracic or lumbar burst fractures. Methods A systematic review of the literature was performed using the National Library of Medicine PubMed database and the Cochrane Library for studies relevant to thoracolumbar trauma. Clinical studies specifically comparing external bracing to no brace for neurologically intact patients with thoracic or lumbar burst fractures were selected for review. Results Three studies out of 1137 met inclusion criteria for review. One randomized controlled trial (level I) and an additional randomized controlled pilot study (level II) provided evidence that both external bracing and no brace equally improve pain and disability in neurologically intact patients with burst fractures. There was no difference in final clinical and radiographic outcomes between patients treated with an external brace vs no brace. One additional level IV retrospective study demonstrated equivalent clinical outcomes for external bracing vs no brace. Conclusion This evidence-based guideline provides a grade B recommendation that management either with or without an external brace is an option given equivalent improvement in outcomes for neurologically intact patients with thoracic and lumbar burst fractures. The decision to use an external brace is at the discretion of the treating physician, as bracing is not associated with increased adverse events compared to no brace. Question Does the use of external bracing improve outcomes in the nonoperative treatment of neurologically intact patients with thoracic and lumbar burst fractures? Recommendation The decision to use an external brace is at the discretion of the treating physician, as the nonoperative management of neurologically intact patients with thoracic and lumbar burst fractures either with or without an external brace produces equivalent improvement in outcomes. Bracing is not associated with increased adverse events compared to not bracing. Strength of Recommendation: Grade B The full version of the guideline can be reviewed at: https://www.cns.org/guideline-chapters/congress-neurological-surgeons-systematic-review-evidence-based-guidelines/chapter_8.

Question 1 Are there classification systems for fractures of the thoracolumbar spine that have been shown to be internally valid and reliable (ie, do these instruments provide consistent information between different care providers)? Recommendation 1 A classification scheme that uses readily available clinical data (eg, computed tomography scans with or without magnetic resonance imaging) to convey injury morphology, such as Thoracolumbar Injury Classification and Severity Scale or the AO Spine Thoracolumbar Spine Injury Classification System, should be used to improve characterization of traumatic thoracolumbar injuries and communication among treating physicians. Strength of Recommendation: Grade B. Question 2 In treating patients with thoracolumbar fractures, does employing a formally tested classification system for treatment decision-making affect clinical outcomes? Recommendation 2 There is insufficient evidence to recommend a universal classification system or severity score that will readily guide treatment of all injury types and thereby affect outcomes. Strength of Recommendation: Grade Insufficient The full version of the guideline can be reviewed at: https://www.cns.org/guideline-chapters/congress-neurological-surgeons-systematic-review-evidence-based-guidelines/chapter_2.

Question 1 Does routine screening for deep venous thrombosis prevent pulmonary embolism (or venous thromboembolism (VTE)-associated morbidity and mortality) in patients with thoracic and lumbar fractures? Recommendation 1 There is insufficient evidence to recommend for or against routine screening for deep venous thrombosis in preventing pulmonary embolism (or VTE-associated morbidity and mortality) in patients with thoracic and lumbar fractures. Strength of Recommendation: Grade Insufficient. Question 2 For patients with thoracic and lumbar fractures, is one regimen of VTE prophylaxis superior to others with respect to prevention of pulmonary embolism (or VTE-associated morbidity and mortality)? Recommendation 2 There is insufficient evidence to recommend a specific regimen of VTE prophylaxis to prevent pulmonary embolism (or VTE-associated morbidity and mortality) in patients with thoracic and lumbar fractures. Strength of Recommendation: Grade Insufficient. Question 3 Is there a specific treatment regimen for documented VTE that provides fewer complications than other treatments in patients with thoracic and lumbar fractures? Recommendation 3 There is insufficient evidence to recommend for or against a specific treatment regimen for documented VTE that would provide fewer complications than other treatments in patients with thoracic and lumbar fractures. Strength of Recommendation: Grade Insufficient. Recommendation 4 Based on published data from pooled (cervical and thoracolumbar) spinal cord injury populations, the use of thromboprophylaxis is recommended to reduce the risk of VTE events in patients with thoracic and lumbar fractures. Consensus Statement by the Workgroup The full version of the guideline can be reviewed at: https://www.cns.org/guideline-chapters/congress-neurological-surgeons-systematic-review-evidence-based-guidelines/chapter_7.

Background Neurosurgical residents have traditionally been instructed on surgical techniques and procedures through an apprenticeship model. Currently, there has been research and interest in expanding the neurosurgical education model. Objective To establish a posterior cervical decompression educational curriculum with a novel cervical simulation model. Methods The Congress of Neurological Surgeons developed a simulation committee to explore and develop simulation-based models. The educational curriculum was developed to have didactic and technical components with the incorporation of simulation models. Through numerous reiterations, a posterior cervical decompression model was developed and a 2-hour education curriculum was established. Results Individual's level of training varied, with 5 postgraduate year (PGY) 2 participants, 1 PGY-3 participant, 2 PGY-5 participants, and 1 attending, with the majority being international participants (6 of 9, 67%). Didactic scores overall improved (7 of 9, 78%). The technical scores of all participants improved from 11 to 24 (mean, 14.1) to 19 to 25 (mean, 22.4). Overall, in the posterior cervical decompression simulator, there was a significant improvement in the didactic scores (P = .005) and the technical scores (P = .02). Conclusion The posterior cervical decompression simulation model appears to be a valuable tool in educating neurosurgery residents in the aspects of this procedure. The combination of a didactic and technical assessment is a useful teaching strategy in terms of educational development.

Surgical education is moving rapidly to the use of simulation for technical training of residents and maintenance or upgrading of surgical skills in clinical practice. To optimize the learning exercise, it is essential that both visual and haptic cues are presented to best present a real-world experience. Many systems attempt to achieve this goal through a total virtual interface.To demonstrate that the most critical aspect in optimizing a simulation experience is to provide the visual and haptic cues, allowing the training to fully mimic the real-world environment.Our approach has been to create a mixed-reality system consisting of a physical and a virtual component. A physical model of the head or spine is created with a 3-dimensional printer using deidentified patient data. The model is linked to a virtual radiographic system or an image guidance platform. A variety of surgical challenges can be presented in which the trainee must use the same anatomic and radiographic references required during actual surgical procedures.Using the aforementioned techniques, we have created simulators for ventriculostomy, percutaneous stereotactic lesion procedure for trigeminal neuralgia, and spinal instrumentation. The design and implementation of these platforms are presented.The system has provided the residents an opportunity to understand and appreciate the complex 3-dimensional anatomy of the 3 neurosurgical procedures simulated. The systems have also provided an opportunity to break procedures down into critical segments, allowing the user to concentrate on specific areas of deficiency.

BACKGROUND:Surgical simulators are useful in many surgical disciplines to augment residency training. Duty hour restrictions and increasing emphasis on patient safety and attending oversight have changed neurosurgical education from the traditional apprenticeship model. The Congress of Neurological Surgeons Simulation Committee has been developing neurosurgical simulators for the purpose of enhancing resident education and assessing proficiency.OBJECTIVE:To review the initial experience with an anterior cervical diskectomy and fusion (ACDF) simulator.METHODS:The first ACDF training module was implemented at the 2012 Congress of Neurological Surgeons Annual Meeting. The 90-minute curriculum included a written pretest, didactics, a practical pretest on the simulator, hands-on training, a written posttest, a practical posttest, and postcourse feedback. Didactic material covered clinical indications for ACDF, comparison with other cervical procedures, surgical anatomy and approach, principles of arthrodesis and spinal fixation, and complication management. Written pretests and posttests were administered to assess baseline knowledge and evidence of improvement after the module. Qualitative evaluation of individual performance on the practical (simulator) portion was included.RESULTS:Three neurosurgery residents, 2 senior medical students, and 1 attending neurosurgeon participated in the course. The pretest scores were an average 9.2 (range, 6-13). Posttest scores improved to 11.0 (range, 9-13; P = .03).CONCLUSION:Initial experience with the ACDF simulator suggests that it may represent a meaningful training module for residents. Simulation will be an important training modality for residents to practice surgical technique and for teachers to assess competency. Further development of an ACDF simulator and didactic curriculum will require additional verification of simulator validity and reliability.

BACKGROUND The evidence of or against the presence of a 'July phenomenon' in resident teaching hospitals has been inconsistent. Moreover, there are limited data on the "July phenomenon" in the field of neurosurgery. OBJECTIVE To determine whether a "July phenomenon" exists for neurosurgical mortality or complications. METHODS A search of the National Inpatient Sample database from 1998 to 2008 was performed for all admissions for International Classification of Diseases, 9th Revision codes corresponding to nontraumatic hemorrhage, central nervous system (CNS) trauma, CNS tumor, and hydrocephalus. Generalized linear mixed-model analysis was performed, adjusted for patient demographics and hospital characteristics, for the outcomes of mortality and complications for the month of July compared with all other months in teaching hospitals. RESULTS Generalized linear mixed-model analysis demonstrated that the risk of dying in the month of July vs any other month in a teaching hospital was not statistically different for any of the 4 diagnoses: nontraumatic hemorrhage (P = .071), CNS trauma category (P = .485), CNS tumor category (P = .578), hydrocephalus category (P = .1505). Moreover, the risk of any complication in the month of July vs any other month in a teaching hospital was not statistically different for any of the 4 diagnoses: nontraumatic hemorrhage (P = .529), CNS trauma category (P = .378), CNS tumor category (P = .461), and hydrocephalus category (P = .441). The same findings were true in an analysis of nonteaching hospitals performed as a control. CONCLUSION No "July phenomenon" was found for neurosurgical mortality or complications in patients with nontraumatic hemorrhage, CNS trauma, CNS tumor, or hydrocephalus.

BACKGROUND The Accreditation Council for Graduate Medical Education resident duty-hour restrictions were implemented in July 2003 based on the supposition that resident fatigue contributes to medical errors. OBJECTIVE To examine the effect of duty-hour restrictions on outcome in neurotrauma patients. METHODS The Nationwide Inpatient Sample database was analyzed for a time period with no restrictions (years 1999-2002) compared with a period with restrictions (years 2005-2008) for (1) mortality and (2) complications. We analyzed both teaching and nonteaching hospitals to account for potential differences attributed to non-resident-related factors. RESULTS There were 107,006 teaching hospital and 115,604 nonteaching hospital admissions for neurotrauma. Multivariate logistic regression demonstrated significantly more complications in the time period with restrictions in teaching hospitals. In nonteaching hospitals, there was no difference in complications. In both teaching and nonteaching hospitals, there was no difference in mortality between the 2 time periods. For teaching and nonteaching hospitals, there was no difference in hospital length of stay, but hospital charges were significantly higher in the period with restrictions. The occurrence of a complication was significantly associated with longer hospital length of stay and higher hospital charges in both time periods in both teaching and nonteaching hospitals. CONCLUSION The implementation of the Accreditation Council for Graduate Medical Education resident duty-hour restrictions was associated with increased complications and no change in mortality for neurotrauma patients in teaching hospitals. In nonteaching hospitals, there was no change in complications and mortality. The occurrence of a complication was associated with longer length of stay and higher hospital charges in both time periods in both teaching and nonteaching hospitals.

BACKGROUND: Intermuscular approaches can expose the lumbar spine and minimize muscular trauma and injury. The segmental anatomy of the posterior lumbar musculature allows surgical access through separation of muscle groups and fascicles and provides one to develop intermuscular working channels while preserving the integrity of the muscles and their function. In addition, preservation of the accompanying neurovascular bundles minimizes blood loss, tissue atrophy, and pain. With these approaches, a variety of procedures for decompression, discectomy, interbody fusion, or pedicle screw fixation can be achieved for single or multiple levels without subperiosteal stripping or muscle transection. OBJECTIVE: A detailed description of the relevant surgical anatomy for the muscle-sparing approach to the lumbar spine.

SHAPE MEMORY ALLOYS possess distinct dynamic properties with particular applications in neurosurgery. Because of their unique physical characteristics, these materials are finding increasing application where resiliency, conformation, and actuation are needed. Nitinol, the most frequently manufactured shape memory alloy, responds to thermal and mechanical stimuli with remarkable mechanical properties such as shape memory effect, super-elasticity, and high damping capacity. Nitinol has found particular use in the biomedical community because of its excellent fatigue resistance and biocompatibility, with special interest in neurosurgical applications. The properties of nitinol and its diffusionless phase transformations contribute to these unique mechanical capabilities. The features of nitinol, particularly its shape memory effect, super-elasticity, damping capacity, as well as its biocompatibility and biomechanics are discussed herein. Current and future applications of nitinol and other shape memory alloys in endovascular, spinal, and minimally invasive neurosurgery are introduced. An understanding of the metallurgic properties of nitinol provides a foundation for further exploration of its use in neurosurgical implant design.

Intraoperative manipulation to correct scoliotic deformities relies upon spinal instrumentation for stabilization and fusion. However, novel strategies and innovative implant biotechnologies have emerged, applying natural growth and elongation of the immature spine for the treatment of scoliosis in young patients. In this work, we review the principles of growth modulation and the Hueter-Volkmann law as it applies to experimental models of scoliosis formation and correction. Current implant technologies, including shape memory alloy vertebral staples, growing rods, and vertical expandable titanium prosthetic ribs, are explored, with regards to implant design, surgical techniques, and clinical investigations. An exciting area of spinal implant technology is now becoming available to expand the surgical armamentarium for treating severe scoliotic deformity in young patients.

Study design A retrospective, case-control study was conducted to analyze postoperative outcomes in patients who received local anesthetic infusion pumps after lumbar spinal fusion procedures. Data were collected prospectively via nursing protocol and third party assessment, and analyzed retrospectively. Objective To review the safety and efficacy of continuous infusion of local anesthetic into the subfascial aspects of the wound after lumbar fusion surgery for treatment of postoperative pain, and to determine whether other outcome measures such as postoperative nausea and vomiting, ambulation and length of hospitalization were affected by the presence of the device. Summary of background data Patients who undergo lumbar spine fusion procedures frequently experience significant, debilitating pain related to their surgery. This pain may delay postoperative mobilization, increase length of hospitalization, and require prolonged use of high doses of narcotics. Use of a local anesthetic continuous-infusion pump after surgery may lead to improvements in these outcome variables. Methods After posterior lumbar spine fusion procedures, 26 consecutive patients received the ON-Q PainBuster, which infused 0.5% marcaine via an elastomeric pump into the subfascial aspects of the wound. Retrospective analysis compared each of these patients with a case-matched control patient. Data included pain scores and opiate use during the first 5 postoperative days (PODs), length of hospital stay, and complications. Variables such as age, American Society of Anesthesiologists (ASA) physical status, and surgical procedure were similar between matched cases. One patient was excluded because of active heroine abuse. Results Patients with the ON-Q PainBuster used 41.2% less narcotics on POD 1, 50.1% less on day 2, and 47.1% less on day 3 compared with the control patients. Differences in opiate usage were not statistically significant on POD 4 (45.5% less) and 5 (50.3% less). A lower average pain score was observed among patients with the ON-Q PainBuster on each POD: 39.1% less pain on POD 1, 34.0% on day 2, 45.1% on day 3, 29.5% on day 4, and 43.6% on day 5. No differences were observed in length of hospital stay or complication rate. Conclusion Patients who received the ON-Q PainBuster used less narcotic medications than case-matched patients during the first 3 PODs, and reported lower pain scores during the first 5 PODs. No complications attributable to the device were noted. These results suggest that continuous infusion of local anesthetic into the wound during the immediate postoperative period is a safe and effective technique that results in lower pain scores and narcotic use. Further data may reveal additional benefits such as lower incidence of nausea and vomiting and decreased times to mobility and functional independence.

The fundamental principle of radiosurgery is the focusing of energy within a restricted target volume. In examining the history of radiosurgery, various strategies for addressing this issue of energy containment become apparent. This is the first in a series of articles that reviews the evolution of radiosurgery through the development of instruments for beam generation and delivery for improved conformal therapy. In this first part of the series, we focus specifically on beam generation and the development of particle beams as the initial approach in radiosurgery for focused radiation treatment. We examine the physical characteristics and biological effects of particles and the unique advantage they confer for radiosurgery. We consider clinical studies and treatment of neurological diseases with particles and also assess boron neutron capture therapy as a strategy for selectively targeting neutron beams. Later in this series, we explore methods of beam delivery with the development of stereotactic radiosurgery. Finally, we introduce new concepts and applications in radiosurgery such as nanotechnology, radiation enhancement, ultrasound, near infrared, and free electron lasers. The elaboration of these efforts sets the stage for neurosurgeons to further explore new ideas, develop innovative technology, and advance the practice of radiosurgery.

Objective Several different methodologies for proximal occlusion and retrograde suction decompression of large paraclinoid aneurysms have been reported previously. In this article, we describe the novel use of an endovascular embolectomy device (F.A.S.T. funnel catheter; Genesis Medical Interventional, Inc., Redwood City, CA) for temporary internal carotid artery occlusion and suction decompression of an intracranial aneurysm to facilitate surgical clip ligation. The combination of atraumatic occlusion technology and large lumen size makes this technique safer and easier. Clinical presentation A 53-year-old woman with progressive headaches underwent computed tomographic angiography, which revealed an unruptured large left paraclinoid aneurysm. Cerebral angiography confirmed the diagnosis. The patient did not tolerate a balloon test occlusion for therapeutic Hunterian internal carotid occlusion. The patient was subsequently taken to the operating room for a craniotomy and clip ligation of the aneurysm. Intervention A standard left pterional craniotomy was performed with opening of the sylvian fissure and exposure of the left paraclinoid aneurysm. Intraoperative angiography with introduction of a new endovascular embolectomy device was performed. The device was deployed to achieve temporary occlusion of the cervical internal carotid artery, and aspiration through the central lumen allowed for retrograde suction decompression of the aneurysm. Collapse of the aneurysm through this technique permitted visualization of the aneurysmal neck with successful clip ligation. Conclusion A new endovascular embolectomy device can be used to safely perform suction decompression of large paraclinoid aneurysms to facilitate clip ligation.