Utilization of Augmented Reality Head-Mounted Display for the Surgical Management of Thoracolumbar Spinal Trauma.

Background and Objectives: Augmented reality head-mounted display (AR-HMD) is a novel technology that provides surgeons with a real-time CT-guided 3-dimensional recapitulation of a patient's spinal anatomy. In this case series, we explore the use of AR-HMD alongside more traditional robotic assistance in surgical spine trauma cases to determine their effect on operative costs and perioperative outcomes. Materials and Methods: We retrospectively reviewed trauma patients who underwent pedicle screw placement surgery guided by AR-HMD or robotic-assisted platforms at an academic tertiary care center between 1 January 2021 and 31 December 2022. Outcome distributions were compared using the Mann-Whitney U test. Results: The AR cohort (n = 9) had a mean age of 66 years, BMI of 29.4 kg/m2, Charlson Comorbidity Index (CCI) of 4.1, and Surgical Invasiveness Index (SII) of 8.8. In total, 77 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 378 mL, 0.78 units transfused, 398 min spent in the operating room, and a 20-day LOS. The robotic cohort (n = 13) had a mean age of 56 years, BMI of 27.1 kg/m2, CCI of 3.8, and SII of 14.2. In total, 128 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 432 mL, 0.46 units transfused units used, 331 min spent in the operating room, and a 10.4-day LOS. No significant difference was found between the two cohorts in any outcome metrics. Conclusions: Although the need to address urgent spinal conditions poses a significant challenge to the implementation of innovative technologies in spine surgery, this study represents an initial effort to show that AR-HMD can yield comparable outcomes to traditional robotic surgical techniques. Moreover, it highlights the potential for AR-HMD to be readily integrated into Level 1 trauma centers without requiring extensive modifications or adjustments.

Neurosurgeons' Perspectives on Vascular Entrustable Professional Activities.

This article discusses subspecialty Canadian neurosurgeons' perceptions of entrustable professional activities (EPAs) assessments and variabilities prior to the implementation of the Competence by Design (CBD) system in Canada. Vascular neurosurgeons were asked to reflect on how they would evaluate and give feedback to neurosurgery residents concerning the EPA "Performing surgery for patients with an intracranial aneurysm." Interviews were transcribed and analyzed using a deductive approach. Themes were derived from these interviews and reflected on the subjectivity and biases present in the EPA assessment forms. Indeed, faculty may require more training in the transitioning to a CBD evaluation system.

Characteristics of shunt failure in 38,095 adult shunt insertion surgeries: a systematic review and meta-analysis.

OBJECTIVE: The management of excess CSF in patients with hydrocephalus typically requires using a shunt to divert CSF. Unfortunately, there is a high rate of shunt failure despite improvements in device components and insertion techniques. Reoperation is frequently necessary, which contributes to patient harm and increased healthcare costs. While factors affecting shunt failure are well defined in the pediatric population, information regarding adults is lacking. The authors undertook a systematic review and meta-analysis to determine how shunt failure in the adult population is reported and investigated the etiologies of shunt failure. METHODS: This review is reported according to PRIMSA and utilized the MEDLINE, Embase, and Google Scholar databases. Abstracts were screened by two independent reviewers, and data were extracted in duplicate by two independent reviewers. Statistical analyses were performed using SPSS and Stata. RESULTS: The pooled rates of shunt failure were 10% (95% CI 5%-15%) in studies with a mean follow-up time of less than 1 year, 12% (95% CI 8%-14%) with a follow-up time between 1 and 2 years, and 32% in studies with a follow-up time of 2 years or greater (95% CI 19%-43%). The pooled rate of failure was 17% across all studies. The most common cause of shunt failure was obstruction at 3.0% (95% CI 2%-4%), accounting for 23.2% of shunt failures. Infection was the second most common at 2.8% (95% CI 2%-3%), accounting for 22.5% of shunt failures. The most common location of shunt failure was the distal catheter, with a failure rate of 4.0% (95% CI 3%-5%), accounting for 33.4% of shunt failures. The definition of shunt failure was heterogeneous and varied depending on institutional practices. The combination of symptoms with either CT or MRI was the most frequently reported method for assessing shunt failure. CONCLUSIONS: Important variation regarding how to define, investigate, and report shunt failure was identified. The overall shunt failure rate in adults is at least 32% after 2 years, which, while lower than that typically reported in the pediatric population, is significant. The most common causes of shunt failure in adults are infection and obstruction. The most common site of failure occurred at the distal catheter, highlighting the need to develop strategies to both report and mitigate distal shunt failure in adult shunt patients.

Implementation of competence by design in Canadian neurosurgery residency programs.

OBJECTIVE: The Royal College of Physicians and Surgeons of Canada (RCPSC) recently redesigned the Canadian neurosurgery residency training curriculum by implementing a competency-based model of training known as Competence by Design (CBD) centered around the assessment of Entrustable Professional Activities (EPAs). This sequential explanatory mixed-methods study evaluated potential benefits and pitfalls of CBD in Canadian neurosurgery residency education. METHODS: Two four-month interval surveys were distributed to all Canadian neurosurgery residents participating in CBD. The surveys assessed important educational components: CBD knowledge of key stakeholders, potential system barriers, and educational/psychological impacts on residents. Paired t-tests were done to assess changes over time. Based on longitudinal survey responses, semi-structured interviews were conducted to investigate in-depth residents' experience with CBD in neurosurgery. The qualitative analysis followed an explanatory approach, and a thematic analysis was performed. RESULTS: Surveys had 82% average response rate (n = 25). Over time, most residents self-reported that they retrospectively understood concepts around CBD intentions (p = 0.02). Perceived benefits included faculty evaluations with more feedback that was clearer and more objective (53% and 51%). Pitfalls included the amount of time needed to navigate through EPAs (90%) and residents forgetting to initiate EPA forms (71%). There was no significant change over time. During interviews, five key themes were found. Potential solutions identified by residents to enhance their experience included learning analytics data availability, mobile app refinement, and dedicated time to integrate EPAs in the workflow. CONCLUSION: This study was the first to assess resident-perceived benefits and pitfalls of the neurosurgery CBD training program in an educational framework context. In general, residents believed that theoretical principles behind CBD were valuable, but that technological ability and having enough time to request EPA assessments were significant barriers to success. Long-term studies are required to determine the definitive outcomes of CBD on residents' performance and ultimately, on patient care.

Primary and metastatic glioblastoma of the spine in the pediatric population: a systematic review.

Pediatric glioblastoma multiforme (GBM) involving the spine is an aggressive tumor with a poor quality of life for patients. Despite this, there is only a limited number of reports describing the outcomes of pediatric spinal GBMs, both as primary spinal GBMs and metastases from an intracranial tumor. Here, we performed an individual patient meta-analysis to characterize factors affecting prognosis of pediatric spinal GBM. MEDLINE, Embase, and the Cochrane databases were searched for published studies on GBMs involving the spine in pediatric patients (age ≤ 21 years old). Factors associated with the survival were assessed with multi-factor ANOVAs, Cox hazard regression, and Kaplan-Meier analyses. We extracted data on 61 patients with spinal GBM from 40 studies that met inclusion criteria. Median survival was significantly longer in the primary spinal GBM compared that those with metastatic GBM (11 vs 3 months, p < 0.001). However, median survival of metastatic GBM patients was 10 months following diagnosis of their primary brain tumor, which was not different from that of primary spinal GBM patients (p = 0.457). Among primary spinal GBM patients, chemotherapy (hazard ratio (HR) = 0.255 [0.106-0.615], p = 0.013) and extent of resection (HR = 0.582 [0.374-0.905], p = 0.016) conferred a significant survival benefit. Younger age (less than 14 years) was associated with longer survival in patients treated with chemotherapy than those who did not undergo chemotherapy (ß = - 1.12, 95% CI [- 2.20, - 0.03], p < 0.05). In conclusion, survival after presentation of metastases from intracranial GBM is poor in the pediatric population. In patients with metastatic GBM, chemotherapy may have provided the most benefit in young patients, and its efficacy might have an association with extent of surgical resection.

A Meta-Analysis of Surgical Outcomes in 25727 Patients Undergoing Anterior Cervical Discectomy and Fusion or Anterior Cervical Corpectomy and Fusion for Cervical Deformity.

STUDY DESIGN: Systematic Review. OBJECTIVES: To evaluate which cervical deformity correction technique between anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) produces better clinical, radiographic, and operative outcomes. METHODS: We conducted a meta-analysis comparing studies involving ACDF and ACCF. Adult patients with either original or previously treated cervical spine deformities were included. Two independent reviewers categorized extracted data into clinical, radiographic, and operative outcomes, including complications. Clinical assessments included patient-reported outcomes; radiographic evaluations examined C2-C7 Cobb angle, T1 slope, T1-CL, C2-7 SVA, and graft stability. Surgical measures included surgery duration, blood loss, hospital stay, and complications. RESULTS: 26 studies (25727 patients) met inclusion criteria and were extracted. Of these, 14 studies (19077 patients) with low risk of bias were included in meta-analysis. ACDF and ACCF similarly improve clinical outcomes in terms of JOA and NDI, but ACDF is significantly better at achieving lower VAS neck scores. ACDF is also more advantageous for improving cervical lordosis and minimizing the incidence of graft complications. While there is no significant difference between approaches for most surgical complications, ACDF is favorable for reducing operative time, intraoperative blood loss, and length of hospital stay. CONCLUSIONS: While both techniques benefit cervical deformity patients, when both techniques are feasible, ACDF may be superior with respect to VAS neck scores, cervical lordosis, graft complications and certain perioperative outcomes. Further studies are recommended to address outcome variability and refine surgical approach selection.

Posterior Transdural Approach for Thoracic Corpectomies in the Setting of Complex Spine Deformity Reconstruction.

BACKGROUND AND OBJECTIVE: There are many surgical approaches for execution of a thoracic corpectomy. In cases of challenging deformity, traditional posterior approaches might not be sufficient to complete the resection of the vertebral body. In this technical note, we describe indications and technique for a transdural multilevel high thoracic corpectomy. METHODS: A 25-year-old man with a history of neurofibromatosis type 1 presented with instrumentation failure after a previous T1-T12 posterior spinal fusion, extensive laminectomy, and tumor resection. The patient presented with progressive back pain, had broad dural ectasia, and a progressive kyphotic rotational and anteriorly translated spinal deformity. To resect the medial-most aspect of the vertebral body, a bilateral extracavitary approach was attempted, but was found insufficient. A transdural approach was subsequently performed. A left paramedian durotomy was made, followed by generous arachnoid dissection, bilateral dentate ligament division, and T4 rootlet sacrifice to mobilize the spinal cord. A ventral durotomy was then made and the ventral dura was reflected over the spinal cord to protect it while drilling. The corpectomy was then completed. The ventral and dorsal durotomies were closed primarily and reinforced with fibrin glue and fibrin sealant patch. The corpectomy defect was filled with nonstructural autograft. RESULTS: The focal kyphosis was corrected with a combination of rod contouring, compression, and in situ bending. During the surgery, the patient had stable neuromonitoring data, and postoperatively had no neurological deficits. On follow-up until 1 year, the patient presented with no signs of cerebrospinal spinal leaks, no motor or sensory deficits, minimal incisional pain, and significantly improved posture. CONCLUSION: Complex high thoracic (T3-5) ventral pathology inaccessible via a bilateral extracavitary approach may be accessed via a transdural approach as opposed to an anterior/lateral transthoracic approach that requires mobilization of cardiovascular structures or scapula.

Clinical Capacity Building Through Partnerships: Boots on the Ground in Global Neurosurgery.

Global neurosurgery seeks to provide quality neurosurgical health care worldwide and faces challenges because of historical, socioeconomic, and political factors. To address the shortfall of essential neurosurgical procedures worldwide, dyads between established neurosurgical and developing centers have been established. Concerns have been raised about their effectiveness and ability to sustain capacity development. Successful partnerships involve multiple stakeholders, extended timelines, and twinning programs. This article outlines current initiatives and challenges within the neurosurgical community. This narrative review aims to provide a practical tool for colleagues embarking on clinical partnerships, the Engagements and assets, Capacity, Operative autonomy, Sustainability, and scalability (ECOSystem) of care. To create the ECOSystem of care in global neurosurgery, the authors had multiple online discussions regarding important points in the practical tool. All developed tiers were expanded based on logistics, clinical, and educational aspects. An online search was performed from August to November 2023 to highlight global neurosurgery partnerships and link them to tiers of the ECOSystem. The ECOSystem of care involves 5 tiers: Tiers 0 (foundation), 1 (essential), 2 (complexity), 3 (autonomy), and 4 (final). A nonexhaustive list of 16 neurosurgical partnerships was created and serves as a reference for using the ECOSystem. Personal experiences from the authors through their partnerships were also captured. We propose a tiered approach for capacity building that provides structured guidance for establishing neurosurgical partnerships with the ECOSystem of care. Clinical partnerships in global neurosurgery aim to build autonomy, enabling independent provision of quality healthcare services.

Pedicle screw placement in the cervical vertebrae using augmented reality-head mounted displays: a cadaveric proof-of-concept study.

BACKGROUND: The accurate and safe positioning of cervical pedicle screws is crucial. While augmented reality (AR) use in spine surgery has previously demonstrated clinical utility in the thoracolumbar spine, its technical feasibility in the cervical spine remains less explored. PURPOSE: The objective of this study was to assess the precision and safety of AR-assisted pedicle screw placement in the cervical spine. STUDY DESIGN: In this experimental study, 5 cadaveric cervical spine models were instrumented from C3 to C7 by 5 different spine surgeons. The navigation accuracy and clinical screw accuracy were evaluated. METHODS: Postprocedural CT scans were evaluated for clinical accuracy by 2 independent neuroradiologists using the Gertzbein-Robbins scale. Technical precision was assessed by calculating the angular trajectory (°) and linear screw tip (mm) deviations in the axial and sagittal planes from the virtual pedicle screw position as recorded by the AR-guided platform during the procedure compared to the actual pedicle screw position derived from postprocedural imaging. RESULTS: A total of forty-one pedicle screws were placed in 5 cervical cadavers, with each of the 5 surgeons navigating at least 7 screws. Gertzbein-Robbins grade of A or B was achieved in 100% of cases. The mean values for tip and trajectory errors in the axial and sagittal planes between the virtual versus actual position of the screws was less than 3 mm and 30°, respectively (p<.05). None of the cervical screws violated the cortex by more than 2 mm or displaced neurovascular structures. CONCLUSIONS: AR-assisted cervical pedicle screw placement in cadavers demonstrated clinical accuracy comparable to existing literature values for image-guided navigation methods for the cervical spine. CLINICAL SIGNIFICANCE: This study provides technical and clinical accuracy data that supports clinical trialing of AR-assisted subaxial cervical pedicle screw placement.

Cervical spinal cord compression from subdural hematoma caused by traumatic nerve root avulsion: illustrative case.

BACKGROUND: Posttraumatic intradural hematomas of the cervical spine are rare findings that may yield significant neurological deficits if they compress the spinal cord. These compressive hematomas require prompt surgical evacuation. In certain instances, intradural hematomas may form from avulsion of cervical nerve roots. OBSERVATIONS: The authors present the case of a 29-year-old male who presented with right upper-extremity weakness in the setting of polytrauma after a motor vehicle accident. He had no cervical fractures but subsequently developed right lower-extremity weakness. Magnetic resonance imaging (MRI) demonstrated a compressive hematoma of the cervical spine that was initially read as an epidural hematoma. However, intraoperatively, it was found to be a subdural hematoma, eccentric to the right, stemming from an avulsion of the right C6 nerve root. LESSONS: Posttraumatic cervical subdural hematomas require rapid surgical evacuation if neurological deficits are present. The source of the hematoma may be an avulsed nerve root, and the associated deficits may be unilateral if the hematoma is eccentric to one side. Surgeons should be prepared for the possibility of an intradural hematoma even in instances in which MRI appears consistent with an epidural hematoma.

Rapid Implementation of a 3-Dimensional-Printed Patient-Specific Titanium Sacrum Implant for Severe Neuropathic Spinal Arthropathy and Guide to Compassionate US Regulatory Approval.

BACKGROUND AND OBJECTIVE: Rapid design and production of patient-specific 3-dimensional-printed implants (3DPIs) present a novel opportunity to restore the biomechanically demanding integrity of the lumbopelvic junction. We present a unique case of a 61-year-old patient with severe neuropathic spinal arthropathy (Charcot spine) who initially underwent a T4-to-sacrum spinal fusion. Massive bone destruction led to dissociation of his upper body from his pelvis and legs. Reconstruction of the spinopelvic continuity was planned with the aid of a personalized lumbosacral 3DPI. METHOD: Using high-resolution computed tomography scans, the custom 3DPI was made using additive titanium manufacturing. The unique 3DPI consisted of (1) a sacral platform with iliac screws, (2) modular corpectomy device with rigid connection to the sacral platform, and (3) anterior plate connection with screws for proximal fixation. The procedures to obtain compassionate use Food and Drug Administration approval were followed. The patient underwent debridement of a chronically open wound before undertaking the 3-stage reconstructive procedure. The custom 3DPI and additional instrumentation were inserted as part of a salvage rebuilding procedure. RESULTS: The chronology of the rapid implementation of the personalized sacral 3DPI from decision, design, manufacturing, Food and Drug Administration approval, and surgical execution lasted 28 days. The prosthesis was positioned in the defect according to the expected anatomic planes and secured using a screw-rod system and a vascularized fibular bone strut graft. The prosthesis provided an ideal repair of the lumbosacral junction and pelvic ring by merging spinal pelvic fixation, posterior pelvic ring fixation, and anterior spinal column fixation. CONCLUSION: To the best of our knowledge, this is the first case of a multilevel lumbar, sacral, and sacropelvic neuropathic (Charcot) spine reconstruction using a 3DPI sacral prosthesis. As the prevalence of severe spine deformities continues to increase, adoption of 3DPIs is becoming more relevant to offer personalized treatment for complex deformities.

Clinical outcomes in pediatric hydrocephalus patients treated with endoscopic third ventriculostomy and choroid plexus cauterization: a systematic review and meta-analysis.

OBJECTIVE: Endoscopic third ventriculostomy and choroid plexus cauterization (ETV+CPC) is a novel procedure for infant hydrocephalus that was developed in sub-Saharan Africa to mitigate the risks associated with permanent implanted shunt hardware. This study summarizes the hydrocephalus literature surrounding the ETV+CPC intraoperative abandonment rate, perioperative mortality rate, cerebrospinal fluid infection rate, and failure rate. METHODS: This systematic review and meta-analysis followed a prespecified protocol and abides by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search strategy using MEDLINE, EMBASE, PsychInfo, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Scopus, and Web of Science was conducted from database inception to October 2019. Studies included controlled trials, cohort studies, and case-control studies of patients with hydrocephalus younger than 18 years of age treated with ETV+CPC. Pooled estimates were calculated using DerSimonian and Laird random-effects modeling, and the significance of subgroup analyses was tested using meta-regression. The quality of the pooled outcomes was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: After screening and reviewing 12,321 citations, the authors found 16 articles that met the inclusion criteria. The pooled estimate for the ETV+CPC failure rate was 0.44 (95% CI 0.37-0.51). Subgroup analysis by geographic income level showed statistical significance (p < 0.01), with lower-middle-income countries having a lower failure rate (0.32, 95% CI 0.28-0.36) than high-income countries (0.53, 95% CI 0.47-0.60). No difference in failure rate was found between hydrocephalus etiology (p = 0.09) or definition of failure (p = 0.24). The pooled estimate for perioperative mortality rate (n = 7 studies) was 0.001 (95% CI 0.00-0.004), the intraoperative abandonment rate (n = 5 studies) was 0.04 (95% CI 0.01-0.08), and the postoperative CSF infection rate (n = 5 studies) was 0.0004 (95% CI 0.00-0.003). All pooled outcomes were found to be low-quality evidence. CONCLUSIONS: This systematic review and meta-analysis provides the most comprehensive pooled estimate for the ETV+CPC failure rate to date and demonstrates, for the first time, a statistically significant difference in failure rate by geographic income level. It also provides the first reported pooled estimates for the risk of ETV+CPC perioperative mortality, intraoperative abandonment, and CSF infection. The low quality of this evidence highlights the need for further research to improve the understanding of these critical clinical outcomes and their relevant explanatory variables and thus to appreciate which patients may benefit most from an ETV+CPC. Systematic review registration no.: CRD42020160149 (https://www.crd.york.ac.uk/prospero/).

Spontaneous Spinal Subarachnoid Hemorrhage from a Ruptured Radiculopial Artery Aneurysm.

BACKGROUND: Spontaneous spinal subarachnoid hemorrhage is an uncommon entity and is even rarer when secondary to intraspinal ruptured aneurysm. The clinical presentation of these cases usually includes back pain and headache; however, we report a unique case in which the patient became acutely paraplegic. CASE DESCRIPTION: A 54-year-old woman initially presented with thunderclap headache and interscapular pain. There was no evidence of subarachnoid hemorrhage on noncontrast computed tomography of the head, but lumbar puncture revealed xanthochromia-positive cerebrospinal fluid. Subsequent computed tomography angiography identified a small right superior hypophyseal aneurysm. The patient then became acutely paraplegic during neurosurgical assessment in the emergency department. Urgent magnetic resonance imaging revealed extensive intradural hemorrhage in the cervicothoracic region, prompting emergent surgical decompression. At surgery, this hemorrhage was noted in a subarachnoid location, but no specific source was identified. Postoperative spinal digital subtraction angiography revealed an intraspinal aneurysm of the posterior spinal circulation involving the left T2 radiculopial artery, which was resected in a subsequent uneventful operation within the same hospital admission. CONCLUSIONS: This unique clinical case highlights a rare cause of spontaneous acute paralysis and further demonstrates the safety of obliterating an intraspinal aneurysm via operative resection.

Journal Club Using Virtual Breakout Rooms: Interactive Continuing Education with No Learner Preparation During COVID-19.

INTRODUCTION: As a result of the COVID-19 pandemic, the authors rapidly transitioned an in-person, learner-led medical education journal club (MEJC) to the virtual environment. The "interactive, no-prep" approach, using breakout rooms within a videoconferencing system, required no prior learner preparation. METHODS: From March to May 2020, learners were invited to participate in a monthly 60-minute virtual MEJC. A needs assessment survey informed article selection. Facilitators developed a presentation to provide background and describe the article's research question(s). In breakout groups, learners generated study designs to answer the research question(s). After the actual study methodology and results were revealed, learners engaged in facilitated open discussion. After the session, learners completed an electronic survey to rate perceived usefulness and suggest improvement areas. RESULTS: A total of 15 learners participated; most completed the survey (13/15; 87%). The MEJC was rated as very or extremely useful. Qualitative feedback indicated that it was convenient, allowed creativity, and enabled rich discussion without prior preparation. When possible, improvement suggestions were implemented. DISCUSSION: The authors offer an evidence-based MEJC approach that is free, interactive with virtual breakout rooms and requires no prior learner preparation. Early indicators suggest that others navigating the COVID-19 crisis may want to implement this approach.

Journal Club Using Virtual Breakout Rooms: Interactive Continuing Education with No Learner Preparation During COVID-19.

INTRODUCTION: As a result of the COVID-19 pandemic, the authors rapidly transitioned an in-person, learner-led medical education journal club (MEJC) to the virtual environment. The "interactive, no-prep" approach, using breakout rooms within a videoconferencing system, required no prior learner preparation. METHODS: From March to May 2020, learners were invited to participate in a monthly 60-minute virtual MEJC. A needs assessment survey informed article selection. Facilitators developed a presentation to provide background and describe the article's research question(s). In breakout groups, learners generated study designs to answer the research question(s). After the actual study methodology and results were revealed, learners engaged in facilitated open discussion. After the session, learners completed an electronic survey to rate perceived usefulness and suggest improvement areas. RESULTS: A total of 15 learners participated; most completed the survey (13/15; 87%). The MEJC was rated as very or extremely useful. Qualitative feedback indicated that it was convenient, allowed creativity, and enabled rich discussion without prior preparation. When possible, improvement suggestions were implemented. DISCUSSION: The authors offer an evidence-based MEJC approach that is free, interactive with virtual breakout rooms and requires no prior learner preparation. Early indicators suggest that others navigating the COVID-19 crisis may want to implement this approach.

Natural History and Growth Patterns of Incidentally Discovered Diffusely Infiltrating Low-Grade Gliomas: A Volumetric Study.

BACKGROUND: Incidentally discovered diffusely infiltrating low-grade gliomas (iDLGGs) are rare findings on neuroimaging that pose a challenge to neurosurgeons. There is a paucity of data regarding the natural history of these lesions, and thus management is controversial. We characterize the growth rates and patterns of iDLGGs in a cohort of patients who underwent serial magnetic resonance imaging before surgical treatment. METHODS: We performed a retrospective review of all adult patients (≥18 years old) with diffuse low-grade glioma diagnosed at our institution between April 2004 and April 2016. iDLGG was defined as any lesion discovered on computed tomography or magnetic resonance imaging performed for reasons and/or symptoms not attributable to the lesion and confirmed on histopathology as low-grade glioma. Tumor growth rates and patterns of growth were analyzed in patients who had serial imaging available. RESULTS: Inclusion criteria were met by 15 patients. Mean velocity of diametric expansion was 2.93 mm/year. Of 15 patients, 11 (73.3%) had tumors with an exponential growth pattern, and 4 (26.7%) had a linear growth pattern. Initial tumor volume was positively correlated (r = 0.78) with velocity of diametric expansion. CONCLUSIONS: iDLGGs grow over time, and most exhibit an exponential pattern of growth. Tumor volume at the time of diagnosis is predictive of a faster growth rate, but not the pattern of growth.