Postoperative outcomes following glioblastoma resection using a robot-assisted digital surgical exoscope: a case series.

INTRODUCTION: Maximal extent of resection (EOR) of glioblastoma (GBM) is associated with greater progression free survival (PFS) and improved patient outcomes. Recently, a novel surgical system has been developed that includes a 2D, robotically-controlled exoscope and brain tractography display. The purpose of this study was to assess outcomes in a series of patients with GBM undergoing resections using this surgical exoscope. METHODS: A retrospective review was conducted for robotic exoscope assisted GBM resections between 2017 and 2019. EOR was computed from volumetric analyses of pre- and post-operative MRIs. Demographics, pathology/MGMT status, imaging, treatment, and outcomes data were collected. The relationship between these perioperative variables and discharge disposition as well as progression-free survival (PFS) was explored. RESULTS: A total of 26 patients with GBM (median age = 57 years) met inclusion criteria, comprising a total of 28 cases. Of these, 22 (79%) tumors were in eloquent regions, most commonly in the frontal lobe (14 cases, 50%). The median pre- and post-operative volumes were 24.0 cc and 1.3 cc, respectively. The median extent of resection for the cohort was 94.8%, with 86% achieving 6-month PFS. The most common neurological complication was a motor deficit followed by sensory loss, while 8 patients (29%) were symptom-free. CONCLUSIONS: The robotic exoscope is safe and effective for patients undergoing GBM surgery, with a majority achieving large-volume resections. These patients experienced complication profiles similar to those undergoing treatment with the traditional microscope. Further studies are needed to assess direct comparisons between exoscope and microscope-assisted GBM resection.

Initial biopsy and early re-resection practices in the treatment of glioblastoma among AANS/CNS tumor section surgeons.

INTRODUCTION: Surgical management strategies for glioblastoma (GBM) may differ among neurosurgeons with initial biopsy of suspected tumors and the need for early re-resection of tumors within 30 days of initial surgery. This study was initiated by the American Association of Neurological Surgeons (AANS) and Congress of Neurological Surgeons (CNS) Tumor Section's interest in understanding the rates at which pre- and post-resection procedures, specifically biopsies prior to definitive resection and early re-resections, are performed by U.S. neurosurgeons in the management of GBM. METHODS: A ten-question survey was distributed to members of the AANS/CNS Tumor Section. RESULTS: The survey response rate among AANS/CNS Tumor Section surgeons was approximately 16%. Results showed that a majority of respondents performed surgery on 11-25 GBM cases annually. Of those cases, most neurosurgeons claimed that biopsies are rarely performed prior to tumor resection, but in the < 10% of cases for which biopsies are done, common reasons are to confirm radiological findings or improve the treatment plan. Likewise, re-resections are rare, but in the < 5 cases most neurosurgeons performed annually, common reasons included incomplete initial resections, referrals for greater resection, or unspecified reasons. CONCLUSIONS: Further studies are needed to confirm the results of this study, which shows low rates of stereotactic and open biopsy and early re-resection procedures performed among neurosurgeons. These rates may help form guidelines in the treatment of GBM and encourage the use of surgical adjuncts that increase the extent of resection of these tumors, thereby reducing rates of early recurrence.

Neurotrauma Surveillance in National Registries of Low- and Middle-Income Countries: A Scoping Review and Comparative Analysis of Data Dictionaries.

BACKGROUND: Injury is a major global health problem, causing >5 800 000 deaths annually and widespread disability largely attributable to neurotrauma. 89% of trauma deaths occur in low- and middle-income countries (LMICs), however data on neurotrauma epidemiology in LMICs is lacking. In order to support neurotrauma surveillance efforts, we present a review and analysis of data dictionaries from national registries in LMICs. METHODS: We performed a scoping review to identify existing national trauma registries for all LMICs. Inclusion/ exclusion criteria included articles published since 1991 describing national registry neurotrauma data capture methods in LMICs. Data sources included PubMed and Google Scholar using the terms "trauma/neurotrauma registry" and country name. Resulting registries were analyzed for neurotrauma-specific data dictionaries. These findings were augmented by data from direct contact of neurotrauma organizations, health ministries, and key informants from a convenience sample. These data were then compared to the World Health Organization (WHO) minimum dataset for injury (MDI) from the international registry for trauma and emergency care (IRTEC). RESULTS: We identified 15 LMICs with 16 total national trauma registries tracking neurotrauma-specific data elements. Among these, Cameroon had the highest concordance with the MDI, followed by Colombia, Iran, Myanmar and Thailand. The MDI elements least often found in the data dictionaries included helmet use, and alcohol level. Data dictionaries differed significantly among LMICs. Common elements included Glasgow Coma Score, mechanism of injury, anatomical site of injury and injury severity scores. Limitations included low response rate in direct contact methods. CONCLUSION: Significant heterogeneity was observed between the neurotrauma data dictionaries, as well as a spectrum of concordance or discordance with the MDI. Findings offer a contextually relevant menu of possible neurotrauma data elements that LMICs can consider tracking nationally to enhance neurotrauma surveillance and care systems. Standardization of nationwide neurotrauma data collection can facilitate international comparisons and bidirectional learning among healthcare governments.

MIS-TLIF Procedure is Improving With Experience: Systematic Review of the Learning Curve Over the Last Decade.

STUDY DESIGN: This was a systematic review. OBJECTIVE: This review evaluates the minimally invasive transforaminal lumbar interbody fusions (MIS-TLIF) learning curve in the literature and compares outcomes during and after completing the curve. SUMMARY OF BACKGROUND DATA: MIS-TLIF are performed for various spine conditions. Proponents cite improved clinical outcomes while critics highlight the steep learning curve to attain proficiency. METHODS: Literature searches on Medline and Embase utilized relevant subject headings and keywords. Manuscripts reporting learning curve statistics were included. Monotonic trends of operative duration were assessed with Mann-Kendall nonparametric testing. RESULTS: Nine studies met inclusion criteria. Number of patients ranged from 26 to 150 (average 83.2, median of 86). Commonly reported metrics included number of procedures to complete the curve, operative duration, blood loss, ambulation time, length of stay, complication rate, follow-up visual analogue scale (VAS) for back and leg pain, and fusion rate. Various methods were employed to determine number of cases to complete the curve, all involving operative duration. Number of cases ranged from 14 to 44. A significant negative trend for operative duration of cases during the learning curve (τ=-0.733, P =0.039) was found over the years that studies were published. Initial complication rates varied from 6.8% to 23.8%. Initial VAS-back and VAS-leg ranged from 0.8 to 2.9 and 0.5 to 2.3, respectively. While definitions of "good" fusion varied, fusion rates meeting Bridwell grade I or II during the learning curve ranged from 84.0% to 95.2%. CONCLUSIONS: Surgeons in their learning curve have become faster at the MIS-TLIF procedure. Clinical outcomes including postoperative pain and fusion rates showed satisfactory results, but surgeons learning the procedure should take measures to minimize complications in early cases, such as utilizing novel navigation technology or supervision from more experienced surgeons. Learning curve research methodology could benefit from standardization.

Intraoperative Navigation in Spine Surgery: Effects on Complications and Reoperations.

INTRODUCTION: Intraoperative navigation during spine surgery improves pedicle screw placement accuracy. However, limited studies have correlated the use of navigation with clinical factors, including operative time and safety. In the present study, we compared the complications and reoperations between surgeries with and without navigation. METHODS: The National Surgical Quality Improvement Project database was queried for posterior cervical and lumbar fusions and deformity surgeries from 2011 to 2018 and divided by navigation use. Patients aged >89 years, patients with deformity aged <25 years, and patients undergoing surgery for tumors, fractures, infections, or nonelective indications were excluded. The demographics and perioperative factors were compared via univariate analysis. The outcomes were compared using multivariable logistic regression adjusting for age, sex, body mass index, American Society of Anesthesiologists class, surgical region, and multiple treatment levels. The outcomes were also compared stratifying by revision status. RESULTS: Navigation surgery patients had had higher American Society of Anesthesiologists class (P < 0.0001), more multiple level surgeries (P < 0.0001), and longer operative times (P < 0.0001). The adjusted analysis revealed that navigated lumbar surgery had lower odds of complications (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.77-0.90; P < 0.0001), blood transfusion (OR, 0.79; 95% CI, 0.72-0.87; P < 0.0001), and wound debridement and/or drainage (OR, 0.66; 95% CI, 0.44-0.97; P = 0.04) compared with non-navigated lumbar surgery. Navigated cervical fusions had increased odds of transfusions (OR, 1.53; 95% CI, 1.06-2.23; P = 0.02). Navigated primary fusion had decreased odds of complications (OR, 0.91; 95% CI, 0.85-0.98; P = 0.01). However, no differences were found in revisions (OR, 0.89; 95% CI, 0.69-1.14; P = 0.34). CONCLUSIONS: Navigated surgery patients experienced longer operations owing to a combination of the time required for navigation, more multilevel procedures, and a larger comorbidity burden, without differences in the incidence of infection. Fewer complications and wound washouts were required for navigated lumbar surgery owing to a greater proportion percentage of minimally invasive cases. The combined use of navigation and minimally invasive surgery might benefit patients with the proper indications.

Seasonal Effects on Surgical Site Infections Following Spine Surgery.

BACKGROUND: Studies investigating seasonality as a risk factor for surgical site infections (SSIs) after spine surgery show mixed results. This study used national data to analyze seasonal effects on spine surgery SSIs. METHODS: National Surgical Quality Improvement Program data (2011-2018) were queried for posterior cervical fusions (PCFs), cervical laminoplasties, posterior lumbar fusions (PLFs), lumbar laminectomies, and deformity surgeries. Patients aged >89 and procedures for tumors, fractures, infections, and nonelective indications were excluded. Patients were divided into warm (admitted April-September) and cold (admitted October-March) seasonal groups. End points were SSIs and reoperations for wound débridement/drainage. Stratified analyses were performed by surgery type and pre-versus postdischarge infections. RESULTS: Overall (N = 208,291), SSIs were more likely in the warm season (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.08-1.23, P < 0.0001) and for PCFs (OR 1.40, 95% CI 1.08-1.80, P = 0.011), PLFs (OR 1.15, 95% CI 1.04-1.28, P = 0.006), and lumbar laminectomies (OR 1.13, 95% CI 1.03-1.25, P = 0.014). Postdischarge infections were also more likely in the warm season overall (OR 1.15, 95% CI 1.07-1.23, P < 0.0001) and for PCFs (OR 1.32, 95% CI 1.01-1.73, P = 0.041), PLFs (OR 1.14, 95% CI 1.03-1.27, P = 0.014), and lumbar laminectomies (OR 1.15, CI 1.04-1.27, P = 0.007). In-hospital infections were more likely during the warm season only for PCFs (OR 2.54, 95% CI 1.06-6.10, P = 0.037). Reoperations for infection were more likely during the warm season for PLFs (OR 1.29, 95% CI 1.08-1.54, P = 0.005). CONCLUSIONS: PCF, PLF, and lumbar laminectomy performed during the warm season had significantly higher odds of SSI, especially postdischarge SSIs. Reoperation rates for wound management were significantly increased during the warm season for PLFs. Identifying seasonal causes merits further investigation and may influence surgeon scheduling and expectations.

5-Aminolevulinic acid for enhanced surgical visualization of high-grade gliomas: a prospective, multicenter study.

OBJECTIVE: Greater extent of resection (EOR) is associated with longer overall survival in patients with high-grade gliomas (HGGs). 5-Aminolevulinic acid (5-ALA) can increase EOR by improving intraoperative visualization of contrast-enhancing tumor during fluorescence-guided surgery (FGS). When administered orally, 5-ALA is converted by glioma cells into protoporphyrin IX (PPIX), which fluoresces under blue 400-nm light. 5-ALA has been available for use in Europe since 2010, but only recently gained FDA approval as an intraoperative imaging agent for HGG tissue. In this first-ever, to the authors' knowledge, multicenter 5-ALA FGS study conducted in the United States, the primary objectives were the following: 1) assess the diagnostic accuracy of 5-ALA-induced PPIX fluorescence for HGG histopathology across diverse centers and surgeons; and 2) assess the safety profile of 5-ALA FGS, with particular attention to neurological morbidity. METHODS: This single-arm, multicenter, prospective study included adults aged 18-80 years with Karnofsky Performance Status (KPS) score > 60 and an MRI diagnosis of suspected new or recurrent resectable HGG. Intraoperatively, 3-5 samples per tumor were taken and their fluorescence status was recorded by the surgeon. Specimens were submitted for histopathological analysis. Patients were followed for 6 weeks postoperatively for adverse events, changes in the neurological exam, and KPS score. Multivariate analyses were performed of the outcomes of KPS decline, EOR, and residual enhancing tumor volume to identify predictive patient and intraoperative variables. RESULTS: Sixty-nine patients underwent 5-ALA FGS, providing 275 tumor samples for analysis. PPIX fluorescence had a sensitivity of 96.5%, specificity of 29.4%, positive predictive value (PPV) for HGG histopathology of 95.4%, and diagnostic accuracy of 92.4%. Drug-related adverse events occurred at a rate of 22%. Serious adverse events due to intraoperative neurological injury, which may have resulted from FGS, occurred at a rate of 4.3%. There were 2 deaths unrelated to FGS. Compared to preoperative KPS scores, postoperative KPS scores were significantly lower at 48 hours and 2 weeks but were not different at 6 weeks postoperatively. Complete resection of enhancing tumor occurred in 51.9% of patients. Smaller preoperative tumor volume and use of intraoperative MRI predicted lower residual tumor volume. CONCLUSIONS: PPIX fluorescence, as judged by the surgeon, has a high sensitivity and PPV for HGG. 5-ALA was well tolerated in terms of drug-related adverse events, and its application by trained surgeons in FGS for HGGs was not associated with any excess neurological morbidity.

Medical Student Publications in Neurosurgery: At Which U.S. Academic Institutions Do Medical Students Publish Most?

BACKGROUND: The neurosurgery residency match is a competitive process. While medical research offers esteemed learning opportunities, productivity is closely evaluated by residency programs. Accordingly, students work diligently to make contributions on projects within their neurosurgery departments. The present study evaluated medical student research productivity for each of the 118 U.S. neurosurgery residency programs. METHODS: A retrospective review of publications for 118 neurosurgery programs from January 1, 2015, to April 1, 2020, was performed. The primary outcome was any publication with a medical student as the first author. Secondary outcomes included number of faculty in each department, department region, and medical school ranking. The number of student first author publications was compared among programs, regions, and medical schools. RESULTS: Mean numbers of medical student first author publications and faculty members per institution were 16.27 and 14.46, respectively. The top 3 neurosurgery departments with the greatest number of student first author publications were Johns Hopkins University, Brigham and Women's Hospital, and University of California, San Francisco. Salient findings included a positive correlation between the number of medical student first author publications from a neurosurgery department and the number of departmental faculty (P < 0.001, R = 0.69). Additionally, the mean number of first author medical student publications at the top 30 programs was higher than the mean for the remaining programs (P < 0.0001). CONCLUSIONS: This study is the first to evaluate neurosurgery medical student productivity in North America. By systematizing first authorships, incoming students who desire to pursue neurosurgery can be informed of institutions with student involvement, and departments that use medical student expertise can be recognized.

Objectively Assessing Sports Concussion Utilizing Visual Evoked Potentials.

A portable system capable of measuring steady-state visual-evoked potentials (SSVEP) was developed to provide an objective, quantifiable method of electroencephalogram (EEG) testing following a traumatic event. In this study, the portable system was used on 65 healthy rugby players throughout a season to determine whether SSVEP are a reliable electrophysiological biomarker for concussion. Preceding the competition season, all players underwent a baseline SSVEP assessment. During the season, players were re-tested within 72 h of a match for either test-retest reliability or post-injury assessment. In the case of a medically diagnosed concussion, players were reassessed again once deemed recovered by a physician. The SSVEP system consisted of a smartphone housed in a VR-frame delivering a 15 Hz flicker stimulus, while a wireless EEG headset recorded occipital activity. Players were instructed to stare at the screen's fixation point while remaining seated and quiet. Electrodes were arranged according to the 10-20 EEG-positioning nomenclature, with O1-O2 being the recording channels while P1-P2 the references and bias, respectively. All EEG data was processed using a Butterworth bandpass filter, Fourier transformation, and normalization to convert data for frequency analysis. Players SSVEP responses were quantified into a signal-to-noise ratio (SNR), with 15 Hz being the desired signal, and summarized into respective study groups for comparison. Concussed players were seen to have a significantly lower SNR compared to their baseline; however, post-recovery, their SNR was not significantly different from the baseline. Test-retest indicated high device reliability for the portable system. An improved portable SSVEP system was also validated against an established EEG amplifier to ensure the investigative design is capable of obtaining research quality EEG measurements. This is the first study to identify differences in SSVEP responses in amateur athletes following a concussion and indicates the potential for SSVEP as an aid in concussion assessment and management.

Utilization of the American Society of Anesthesiologists (ASA) classification system in evaluating outcomes and costs following deformity spine procedures.

PURPOSE: Adult spinal deformity (ASD) has increased prevalence in aging populations. Due to the high cost of surgery, studies have evaluated risk factors that predict readmissions and poor outcomes. The American Society of Anesthesiologists (ASA) classification system has been applied to patients with ASD to assess preoperative health and assess the correlation between ASA class and postoperative complications. This study evaluates the relationship between ASA and complications, length of stay (LOS), and direct costs following spine deformity surgery. METHODS: Patients undergoing spine deformity surgery at a single institution from 2008-2016 were included and stratified based upon ASA status. Primary outcomes included patient demographics, adjusted LOS, and cost of care. Secondary measures compared between cohorts included adverse events, non-home discharge, and readmission rates. RESULTS: 442 patients with ASD were included in this study. Higher ASA class was correlated with greater Elixhauser Comorbidity Index (ECI) scores (p < 0.0001) and older age (p < 0.0001). Univariate analysis showed longer LOS (p < 0.0001) and greater direct costs in patients with higher ASA class (p < 0.0001). Patients in ASA Class III or IV had the greatest incidence of ICU stay when compared to patients without systemic disease (p < 0.0001). Upon multivariable regression analysis, high ASA class was associated with higher rates of non-home discharge (OR 5.0, 95% CI 3.1-8.1). Direct costs were greater for higher ASA class (regression estimate = + $9,666, p = 0.002). CONCLUSION: This study demonstrates that ASA class is correlated with a more complicated postoperative hospital course, greater rates of non-home discharge, total direct costs in spine deformity patients.

Comparison of Cost and Perioperative Outcome Profiles for Primary and Revision Posterior Cervical Fusion Procedures.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: To compare perioperative outcomes and hospitalization costs between patients undergoing primary or revision posterior cervical discectomy and fusion (PCDF). SUMMARY OF BACKGROUND DATA: While prior studies found differences in outcomes between primary and revision anterior cervical discectomy and fusion (ACDF), risk, and outcome profiles for posterior cervical revision procedures have not yet been elucidated. METHODS: Institutional records were queried for cases involving isolated PCDF procedures to evaluate preoperative characteristics and outcomes for patients undergoing primary versus revision PCDF between 2008 and 2016. The primary outcome was perioperative complications, while perioperative and resource utilization measures such as hospitalization length, required stay in the intensive care unit (ICU), direct hospitalization costs, and 30-day emergency department (ED) admissions were explored as secondary outcomes. RESULTS: One thousand one hundred twenty four patients underwent PCDF, with 218 (19.4%) undergoing a revision procedure. Patients undergoing revision procedures were younger (53.0 vs. 60.5 yrs), but had higher Elixhauser scores compared with the non-revision cohort. Revision cases tended to involve fewer spinal segments (3.6 vs. 4.1 segments) and shorter surgical durations (179.3 vs. 206.3 min), without significant differences in estimated blood loss. There were no significant differences in the overall complication rates (P = 0.20), however, the primary cohort had greater rates of required ICU stays (P = 0.0005) and non-home discharges (P = 0.0003). The revision cohort did experience significantly increased odds of 30-day ED admission (P = 0.04) and had higher direct hospitalization (P = 0.03) and surgical (P < 0.0001) costs. CONCLUSION: Complication rates, including incidental durotomy, were similar between primary and revision PCDF cohorts. Although prior surgery status did not predict complication risk, comorbidity burden did. Nevertheless, patients undergoing revision procedures had decreased risk of required ICU stay but greater risk of 30-day ED admission and higher direct hospitalization and surgical costs.Level of Evidence: 3.

A Comparison of Outcomes for Spinal Trauma Patients at Level I and Level II Centers.

STUDY DESIGN: Retrospective analysis of a national database. OBJECTIVE: To characterize the spine trauma population, describe trauma center (TC) resources, and compare rates of outcomes between the American College of Surgeons (ACS) level I and level II centers. SUMMARY OF BACKGROUND DATA: Each year, thousands of patients are treated for spinal trauma in the United States. Although prior analyses have explored postsurgical outcomes for patients with trauma, no study has evaluated these metrics for spinal trauma at level I and level II TCs. MATERIALS AND METHODS: The ACS Trauma Quality Improvement Program was queried for all spinal trauma cases between 2013 and 2015, excluding polytrauma cases, patients discharged within 24 hours, data from TCs without a designated level, and patients transferred for treatment. RESULTS: Although there were similar rates of severe spine traumas (Abbreviated Injury Scale≥3) at ACS level I and level II centers (P=0.7), a greater proportion of level I patients required mechanical ventilation upon emergency department arrival (P=0.0002). Patients at level I centers suffered from higher rates of infectious complications, including severe sepsis (0.58% vs. 0.31%, P=0.02) and urinary tract infections (3.26% vs. 2.34%, P=0.0009). Intensive care unit time (1.90 vs. 1.65 days, P=0.005) and overall length of stay (8.37 days vs. 7.44 days, P<0.0001) was higher at level I TCs. Multivariate regression revealed higher adjusted overall complication rates at level II centers (odds ratio, 1.15, 95% confidence interval, 1.06-1.24; P<0.001), but no difference in mortality (odds ratio, 1.18; 95% confidence interval, 0.92-1.52; P>0.10). CONCLUSIONS: ACS level I TCs possess larger surgical staff and are more likely to be academic centers. Patients treated at level I centers experience fewer overall complications but have a greater incidence of infectious complications. Mortality rates are not statistically different.

A Comparison of the Elixhauser and Charlson Comorbidity Indices: Predicting In-Hospital Complications Following Anterior Lumbar Interbody Fusions.

OBJECTIVE: The Elixhauser Comorbidity Index (ECI) and Charlson Comorbidity Index (CCI) are commonly used measures that use administrative data to characterize a patient's comorbidity burden. The purpose of this study was to compare the ability of these measures to predict outcomes following anterior lumbar interbody fusion. METHODS: The National Inpatient Sample was queried for all ALIF procedures between 2013 and 2014. The area under the receiver operating curve (AUC) was used to compare the ECI and CCI in their ability to predict postoperative complications when incorporated into a base model containing age, sex, race, and primary payer. Percent superiority was computed using AUC values for ECI, CCI, and base models. RESULTS: A total of 43,930 hospitalizations were included in this study. The ECI was superior to the CCI and baseline models in predicting minor (AUC 71 vs. 0.66, P < 0.0001) and major (AUC 0.74 vs. 0.67, P < 0.0001) complications. When evaluating individual complications, the ECI was superior to the CCI in predicting airway complications (65% superior, AUC 0.85 vs. 0.72, P = 0.0001); hemorrhagic anemia (83% superior, AUC 0.71 vs. 0.66, P < 0.0001); myocardial infarction (76% superior, AUC 0.86 vs. 0.67, P < 0.0001); cardiac arrest (75% superior, AUC 0.85 vs. 0.67, P < 0.0001); pulmonary embolism (105% superior, AUC 0.91 vs. 0.71, P < 0.0001); and urinary tract infection (43% superior, AUC 0.76 vs. 0.73, P = 0.046). CONCLUSIONS: The ECI was superior to the CCI in predicting 6 of the 15 complications analyzed in this study. Combined with previous results, the ECI may be a better predictive model in spine surgery.

Patents and Innovation Among Neurosurgeons from the American Association of Neurological Surgeons.

Objective Neurosurgeons have taken on the role of innovators, continuing to move the field forward over the centuries. More recently, innovation has taken the form of new technological devices and therapeutics, which require patenting. The aim of this study is to identify major areas of innovation in the field of neurosurgery by evaluating patent records. Methods This study quantifies the number of patents the American Association of Neurological Surgeons (AANS) neurosurgeons hold across different subspecialties. The United States Patent and Trademark Office (USPTO) patent database was queried using the names of 7,293 AANS members who filed patents between 1976 and 2019. Results A total of 346 (4.7%) AANS neurosurgeons hold a total of 1,025 patents. The number of patents held by each neurosurgeon ranged from one to 109. The areas that patents were filed under include cellular and genetic science (40), drug delivery (45), image guidance (82), neuromodulation (52), pain (7), peripheral nerve stimulation (24), spine (398), surgical devices (148), trauma (16), tumor (78), vascular (67), and other (68). No patents were filed under pediatrics (0). The fields with the greatest number of filed patents are spine, instruments/devices, and image guidance. Conclusion Given the technical nature of the field of neurosurgery, instruments and devices that improve localization, visualization, targeting, and spinal reconstruction are often in demand. Furthermore, since the rates of spinal procedures and implants continue to increase, higher patenting may be motivated by the opportunity to develop new products that can result in royalty payments to neurosurgeons. The advent of new technologies undoubtedly continues to push the field of neurosurgery forward.