Levels of autonomy in FDA-cleared surgical robots: a systematic review

The integration of robotics in surgery has increased over the past decade, and advances in the autonomous capabilities of surgical robots have paralleled that of assistive and industrial robots. However, classification and regulatory frameworks have not kept pace with the increasing autonomy of surgical robots. There is a need to modernize our classification to understand technological trends and prepare to regulate and streamline surgical practice around these robotic systems. We present a systematic review of all surgical robots cleared by the United States Food and Drug Administration (FDA) from 2015 to 2023, utilizing a classification system that we call Levels of Autonomy in Surgical Robotics (LASR) to categorize each robot's decision-making and action-taking abilities from Level 1 (Robot Assistance) to Level 5 (Full Autonomy). We searched the 510(k), De Novo, and AccessGUDID databases in December 2023 and included all medical devices fitting our definition of a surgical robot. 37,981 records were screened to identify 49 surgical robots. Most surgical robots were at Level 1 (86%) and some reached Level 3 (Conditional Autonomy) (6%). 2 surgical robots were recognized by the FDA to have machine learning-enabled capabilities, while more were reported to have these capabilities in their marketing materials. Most surgical robots were introduced via the 510(k) pathway, but a growing number via the De Novo pathway. This review highlights trends toward greater autonomy in surgical robotics. Implementing regulatory frameworks that acknowledge varying levels of autonomy in surgical robots may help ensure their safe and effective integration into surgical practice.

Bibliometric Analysis of the Top 100 Cited Articles and Author H-Indexes on the Surgical Treatment of Trigeminal Neuralgia

INTRODUCTION

Medically refractory cases of trigeminal neuralgia often require treatment escalation. Surgical options include microvascular decompression and percutaneous ablation. This paper provides a bibliometric analysis of the most influential articles on the surgical management of trigeminal neuralgia.

METHODS

The Web of Science database was queried to identify the top 100 cited articles concerning surgical treatment of trigeminal neuralgia. The search terms used included ALL=(("trigeminal neuralgia" OR "tic douloureux" OR "Fothergill's disease" OR "Trifacial neuralgia") AND ("surgical treatment" OR "surgical management" OR "surgery" OR "neurosurgery") NOT ("radiosurgery" OR "gamma knife")). The extracted variables included the first and senior author names, journal, publication year, institution, and surgical modality.

RESULTS

Our bibliometric search yielded 2104 studies, with 41,502 citations overall. Within the top 100 articles, Zakrzewska had the most first author papers (n = 5), and Burchiel had the most senior author papers (n = 6). The Massachusetts General Hospital was the most represented institution (n = 5). The United States was the most represented country (51%). Microvascular decompression was the most studied surgical strategy (51%), followed by percutaneous radiofrequency coagulation (9%), balloon/nerve compression (7%), and glycerol rhizolysis (7%). Some studies assessed multiple treatment modalities (22%). The types of studies included retrospective articles (58%), prospective articles (26%), reviews (10%), anatomic studies (2%), and basic science (1%). Neurosurgery (35%) and the Journal of Neurosurgery (33%) were the most represented journals.

CONCLUSIONS

The current literature consists of retrospective reviews and mostly describes microvascular decompression for trigeminal neuralgia. Future studies should include further characterization of other surgical modalities such as percutaneous radiofrequency thermocoagulation, glycerol injection, and balloon compression.

Complications of Implanted Vagus Nerve Stimulation: A Systematic Review and Meta-analysis

INTRODUCTION

Vagus Nerve Stimulation (VNS) has emerged as a promising tool in ischemic stroke rehabilitation. However, there has been no systematic review summarizing its adverse effects, critical information for patients and providers when obtaining informed consent for this novel treatment. This systematic review and meta-analysis reports the adverse effects of VNS.

METHODS

A systematic review was performed in accordance with PRISMA guidelines to identify common complications after VNS therapy. The search was executed in: Cochrane Central Register of Controlled Trials, Embase, and Ovid MEDLINE. All prospective, randomized controlled trials using implanted VNS therapy in adult patients were eligible for inclusion. Case studies and studies lacking complete complication reports were excluded. Extracted data included technology name, location of implantation, follow-up duration, purpose of VNS, and adverse event rates.

RESULTS

After title-and-abstract screening of 4933 studies, 21 were selected for final inclusion. Across these studies, 1474 patients received VNS implantation. VNS was used as a potential therapy for epilepsy (9), depression (8), anxiety (1), ischemic stroke (1), chronic heart failure (1), and fibromyalgia (1). The 5 most common post-implant adverse events were voice alteration/hoarseness (n=671, 45.5%), paresthesia (n = 233, 15.8%), cough (n = 221, 15.0%), dyspnea (n = 211, 14.3%), and pain (n = 170, 11.5%).

CONCLUSIONS

Complications from VNS are mild and transient, with reduction in severity and number of adverse events with increasing follow-up time. In prior studies, VNS has served as treatment option in several instances of treatment-resistant conditions, such as epilepsy and psychiatric conditions, and its use in stroke recovery and rehabilitation should continue to be explored.

External ventricular drain training in medical students improves procedural accuracy and attitudes towards virtual reality

OBJECTIVE

Neurosurgery residents face a learning curve at the beginning of residency. Virtual reality (VR) training may alleviate challenges through an accessible, reusable, anatomical model.

METHODS

Medical students performed external ventricular drain (EVD) placements in VR to characterize the learning curve from novice to proficient. Distance from catheter to Foramen of Monro and location with respect to ventricle were recorded. Changes in attitudes towards VR were assessed. Neurosurgery residents performed EVD placements to validate proficiency benchmarks. Resident and student impressions of the VR model were compared.

RESULTS

Twenty-one students with no neurosurgical experience and 8 neurosurgery residents participated. Student performance improved significantly from trial 1 to 3 (15 mm [12.1-20.70] vs 9.7 [5.8-15.3], p=.02). Student attitudes regarding VR utility improved significantly post-trial. The distance to Foramen of Monro was significantly shorter for residents than for students in trial 1 (9.05 [8.25-10.73] vs 15 [12.1-20.70], p=.007) and trial 2 (7.45 [6.43-8.3] vs 19.5 [10.9-27.6], p=.002). By trial 3 there was no significant difference (10.1 [8.63-10.95 vs 9.7 [5.8-15.3], p=.62). Residents and students provided similarly positive feedback for VR in resident curricula, patient consent, preoperative practice and planning. Residents provided more neutral-to-negative feedback regarding skill development, model fidelity, instrument movement, and haptic feedback.

CONCLUSIONS

Students showed significant improvement in procedural efficacy which may simulate resident experiential learning. Improvements in fidelity are needed before VR can become a preferred training technique in neurosurgery.

Breaking boundaries through Doctors Reaching Minority Men Exploring Neuroscience: a mentorship model to foster a pipeline for underrepresented minorities

OBJECTIVE

In 2015, the Association of American Medical Colleges report titled "Altering the Course: Black Males in Medicine" showed a decline in the number of Black men matriculating into medical school. To alter this trend, the authors' hypothesis was that formally exposing Black men to the clinical neurosciences during high school would enhance their chances of entering the physician workforce. For this reason, in 2007, the Doctors Reaching Minority Men Exploring Neuroscience (DR. MMEN) program was established at the Icahn School of Medicine at Mount Sinai. The program aimed to provide early exposure, mentorship, and inspiration to high school-age Black and Latinx men. The aim of this study was to evaluate the impact of the DR. MMEN program in the context of the recent race and ethnicity trends among medical school matriculants (MSMs).

METHODS

Association of American Medical Colleges data on MSMs stratified by race and ethnicity were reviewed for the period between 2015 and 2020. Data pertinent to the academic achievements of DR. MMEN participants, such as matriculation to college and/or medical school, were prospectively tracked and incorporated with mixed-methods exit assessment data. Qualitative responses were coded and analyzed using a thematic concept analysis method.

RESULTS

Over the study period, the increase of MSMs in the US was 1.0% and 1.7% for Black and Latinx individuals, respectively. Changes for the male MSM cohort were negligible: 0.3% for Black and 0.7% for Latinx. With respect to DR. MMEN, 42% of participants from 2017 to 2019 earned college scholarships, and 25% of students from the 2017-2018 cohort matriculated to a combined college-medical program. Survey data showed that 100% of DR. MMEN participants found the program useful. Analysis of qualitative data revealed that participants considered pursuing a career in neurosurgery or in another medical field. Diligence and a passion for medicine were identified as the top two most important lessons in the program, and witnessing patient satisfaction and observing a neurosurgery operation were described as the most important experiences. Participants considered availability to give advice and feedback and a passion for teaching as the principal attributes of their mentors.

CONCLUSIONS

Over the past 6 years, the slight increase in Black and Latinx MSMs has not been significant enough to remedy ethnoracial disparities among MSMs. In particular, Black male matriculation to medical school has remained stagnant. The DR. MMEN program is a promising model to inspire young scholars and improve diversity within neuroscience and medicine at large.

The Knosp Criteria Revisited: 3-Dimensional Volumetric Analysis as a Predictive Tool for Extent of Resection in Complex Endoscopic Pituitary Surgery

BACKGROUND

The Knosp criteria have been the historical standard for predicting cavernous sinus invasion, and therefore extent of surgical resection, of pituitary macroadenomas. Few studies have sought to reappraise the utility of this tool after recent advances in visualization and modeling of tumors in complex endoscopic surgery.

OBJECTIVE

To evaluate our proposed alternative method, using 3-dimensional (3D) volumetric imaging, and whether it can better predict extent of resection in nonfunctional pituitary adenomas.

METHODS

Patients who underwent endoscopic transsphenoidal resection of pituitary macroadenomas at our institution were reviewed. Information was collected on neurological, endocrine, and visual function. Volumetric segmentation was performed using 3D Slicer software. Relationship of tumor volume, clinical features, and Knosp grade on extent of resection was examined.

RESULTS

One hundred forty patients were identified who had transsphenoidal resection of nonfunctional pituitary adenomas. Macroadenomas had a median volume of 6 cm 3 (IQR 3.4-8.7), and 17% had a unilateral Knosp grade of at least 3B. On multiple logistic regression, only smaller log-transformed preoperative tumor volume was independently associated with increased odds of gross total resection (GTR; odds ratio: 0.27, 95% CI: 0.07-0.89, P < .05) when controlling for tumor proliferative status, age, and sex (area under the curve 0.67). The Knosp criteria did not independently predict GTR in this cohort ( P > .05, area under the curve 0.46).

CONCLUSION

Increasing use of volumetric 3D imaging may better anticipate extent of resection compared with the Knosp grade metric and may have a greater positive predictive value for GTR. More research is needed to validate these findings and implement them using automated methods.

Seventy-five years of neurosurgery residency training at The Mount Sinai Hospital

The Department of Neurosurgery's residency program at The Mount Sinai Hospital was founded in 1946. The department has its origins in 1914 as a division of general surgery, with Charles Elsberg at the helm. Neurosurgery then became a separate department in 1932 under the leadership of Ira Cohen. Dr. Cohen oversaw the creation of the neurosurgery residency training program 75 years ago. Since its inception, the residency program has graduated 120 residents. For more than 100 years, The Mount Sinai Hospital has been a site of clinical excellence, groundbreaking research, and technological innovation in neurosurgery. Currently, the Department of Neurosurgery has 39 clinical faculty members, performs more than 5300 surgeries and endovascular procedures annually, and is in the top 25 neurosurgical departments for NIH funding.

Accuracy of artificial intelligence for the detection of intracranial hemorrhage and chronic cerebral microbleeds: a systematic review and pooled analysis

BACKGROUND

Artificial intelligence (AI)-driven software has been developed and become commercially available within the past few years for the detection of intracranial hemorrhage (ICH) and chronic cerebral microbleeds (CMBs). However, there is currently no systematic review that summarizes all of these tools or provides pooled estimates of their performance.

METHODS

In this PROSPERO-registered, PRISMA compliant systematic review, we sought to compile and review all MEDLINE and EMBASE published studies that have developed and/or tested AI algorithms for ICH detection on non-contrast CT scans (NCCTs) or MRI scans and CMBs detection on MRI scans.

RESULTS

In total, 40 studies described AI algorithms for ICH detection in NCCTs/MRIs and 19 for CMBs detection in MRIs. The overall sensitivity, specificity, and accuracy were 92.06%, 93.54%, and 93.46%, respectively, for ICH detection and 91.6%, 93.9%, and 92.7% for CMBs detection. Some of the challenges encountered in the development of these algorithms include the laborious work of creating large, labeled and balanced datasets, the volumetric nature of the imaging examinations, the fine tuning of the algorithms, and the reduction in false positives.

CONCLUSIONS

Numerous AI-driven software tools have been developed over the last decade. On average, they are characterized by high performance and expert-level accuracy for the diagnosis of ICH and CMBs. As a result, implementing these tools in clinical practice may improve workflow and act as a failsafe for the detection of such lesions. REGISTRATION-URL: https://www.crd.york.ac.uk/prospero/ Unique Identifier: CRD42021246848.

Suboccipital Craniectomy for an Anterior Foramen Magnum Meningioma-Optimization of Resection Using Intraoperative Augmented Reality: 2-Dimensional Operative Video

Foramen magnum meningiomas represent a challenge in skull base surgery because they frequently implicate the lower cranial nerves, brainstem, and posterior cerebral circulation, including the anterior spinal arteries.1 The use of virtual reality allows for surgical rehearsal based on patient-specific anatomy, thus increasing the surgeon's confidence and assists with bone opening planning by generating navigation-integrated templates.2,3 In this 2-dimensinal operative video, the authors demonstrate the importance of augmented reality (AR) template for the resection of a large intradural anterior foramen magnum meningioma in a 68-year-old patient. Preoperative MRI and virtual reality were used to delineate and define the extent of the tumor, as well as its relationship with nearby vital structures. The lesion measured 4.5 by 2 by 3 cm in the craniocaudal, anteroposterior and transverse axes, respectively, and was causing significant mass effect on the brainstem and spinal cord. Both vertebral arteries had a very close relationship with the tumor. After performing a bilateral craniectomy with a right side far lateral extension, debulking started at the inferior and continued toward the middle portion of the tumor. The most challenging part of the operation was to identify and protect the anterior spinal arteries, for which the AR-assisted preview of the surgical microscope proved of paramount importance. Following the heads-up display of the AR, the lateral portion of the tumor, which was adherent to the ventral surface of the vertebral artery, and then the uppermost portion of the tumor were removed, achieving a gross total resection. Appropriate consent was obtained. Images at 4:10 used with permission. Left from Matsushima T,4 ©2015; Right from Dhandapani et al,5 ©2014.

Endovascular therapy versus microsurgical clipping of unruptured wide-neck aneurysms: a prospective multicenter study with propensity score analysis

OBJECTIVE

Numerous techniques have been developed to treat wide-neck aneurysms (WNAs), each with different safety and efficacy profiles. Few studies have compared endovascular therapy (EVT) with microsurgery (MS). The authors' objective was to perform a prospective multicenter study of a WNA registry using rigorous outcome assessments and to compare EVT and MS using propensity score analysis (PSA).

METHODS

Unruptured, saccular, not previously treated WNAs were included. WNA was defined as an aneurysm with a neck width ≥ 4 mm or a dome-to-neck ratio (DTNR) < 2. The primary outcome was modified Rankin Scale (mRS) score at 1 year after treatment (good outcome was defined as mRS score 0-2), as assessed by blinded research nurses and compared with PSA. Angiographic outcome was assessed using the Raymond scale with core laboratory review (adequate occlusion was defined as Raymond scale score 1-2).

RESULTS

The analysis included 224 unruptured aneurysms in the EVT cohort (n = 140) and MS cohort (n = 84). There were no differences in baseline demographic characteristics, such as proportion of patients with good baseline mRS score (94.3% of the EVT cohort vs 94.0% of the MS cohort, p = 0.941). WNA inclusion criteria were similar between cohorts, with the most common being both neck width ≥ 4 mm and DTNR < 2 (50.7% of the EVT cohort vs 50.0% of the MS cohort, p = 0.228). More paraclinoid (32.1% vs 9.5%) and basilar tip (7.1% vs 3.6%) aneurysms were treated with EVT, whereas more middle cerebral artery (13.6% vs 42.9%) and pericallosal (1.4% vs 4.8%) aneurysms were treated with MS (p < 0.001). EVT aneurysms were slightly larger (p = 0.040), and MS aneurysms had a slightly lower mean DTNR (1.4 for the EVT cohort vs 1.3 for the MS cohort, p = 0.010). Within the EVT cohort, 9.3% of patients underwent stand-alone coiling, 17.1% balloon-assisted coiling, 34.3% stent-assisted coiling, 37.1% flow diversion, and 2.1% PulseRider-assisted coiling. Neurological morbidity secondary to a procedural complication was more common in the MS cohort (10.3% vs 1.4%, p = 0.003). One-year mRS scores were assessed for 218 patients (97.3%), and no significantly increased risk of poor clinical outcome was found for the MS cohort (OR 2.17, 95% CI 0.84-5.60, p = 0.110). In an unadjusted direct comparison, more patients in the EVT cohort achieved a good clinical outcome at 1 year (93.4% vs 84.1%, p = 0.048). Final adequate angiographic outcome was superior in the MS cohort (97.6% of the MS cohort vs 86.5% of the EVT cohort, p = 0.007).

CONCLUSIONS

Although the treatments for unruptured WNA had similar clinical outcomes according to PSA, there were fewer complications and superior clinical outcome in the EVT cohort and superior angiographic outcomes in the MS cohort according to the unadjusted analysis. These results may be considered when selecting treatment modalities for patients with unruptured WNAs.

Endovascular Therapy Versus Microsurgical Clipping of Ruptured Wide Neck Aneurysms (EVERRUN Registry): a multicenter, prospective propensity score analysis

OBJECTIVE

Randomized controlled trials have demonstrated the superiority of endovascular therapy (EVT) compared to microsurgery (MS) for ruptured aneurysms suitable for treatment or when therapy is broadly offered to all presenting aneurysms; however, wide neck aneurysms (WNAs) are a challenging subset that require more advanced techniques and warrant further investigation. Herein, the authors sought to investigate a prospective, multicenter WNA registry using rigorous outcome assessments and compare EVT and MS using propensity score analysis (PSA).

METHODS

Untreated, ruptured, saccular WNAs were included in the analysis. A WNA was defined as having a neck ≥ 4 mm or a dome/neck ratio (DNR) < 2. The primary outcome was the modified Rankin Scale (mRS) score at 1 year posttreatment, as assessed by blinded research nurses (good outcome: mRS scores 0-2) and compared using PSA.

RESULTS

The analysis included 87 ruptured aneurysms: 55 in the EVT cohort and 32 in the MS cohort. Demographics were similar in the two cohorts, including Hunt and Hess grade (p = 0.144) and modified Fisher grade (p = 0.475). WNA type inclusion criteria were similar in the two cohorts, with the most common type having a DNR < 2 (EVT 60.0% vs MS 62.5%). More anterior communicating artery aneurysms (27.3% vs 18.8%) and posterior circulation aneurysms (18.2% vs 0.0%) were treated with EVT, whereas more middle cerebral artery aneurysms were treated with MS (34.4% vs 18.2%, p = 0.025). Within the EVT cohort, 43.6% underwent stand-alone coiling, 50.9% balloon-assisted coiling, 3.6% stent-assisted coiling, and 1.8% flow diversion. The 1-year mRS score was assessed in 81 patients (93.1%), and the primary outcome demonstrated no increased risk for a poor outcome with MS compared to EVT (OR 0.43, 95% CI 0.13-1.45, p = 0.177). The durability of MS was higher, as evidenced by retreatment rates of 12.7% and 0% for EVT and MS, respectively (p = 0.04).

CONCLUSIONS

EVT and MS had similar clinical outcomes at 1 year following ruptured WNA treatment. Because of their challenging anatomy, WNAs may represent a population in which EVT's previously demonstrated superiority for ruptured aneurysm treatment is less relevant. Further investigation into the treatment of ruptured WNAs is warranted.

Augmented reality–assisted microsurgical resection of brain arteriovenous malformations: illustrative case

BACKGROUND

Arteriovenous malformations (AVMs) of the brain are vessel conglomerates of feeding arteries and draining veins that carry a risk of spontaneous and intraoperative rupture. Augmented reality (AR)-assisted neuronavigation permits continuous, real-time, updated visualization of navigation information through a heads-up display, thereby potentially improving the safety of surgical resection of AVMs.

OBSERVATIONS

The authors report a case of a 37-year-old female presenting with a 2-year history of recurrent falls due to intermittent right-sided weakness and increasing clumsiness in the right upper extremity. Magnetic resonance imaging, magnetic resonance angiography, and cerebral angiography of the brain revealed a left parietal Spetzler-Martin grade III AVM. After endovascular embolization of the AVM, microsurgical resection using an AR-assisted neuronavigation system was performed. Postoperative angiography confirmed complete obliteration of arteriovenous shunting. The postsurgical course was unremarkable, and the patient remains in excellent health.

LESSONS

Our case describes the operative setup and intraoperative employment of AR-assisted neuronavigation for AVM resection. Application of this technology may improve workflow and enhance patient safety.

Post-operative vision loss: analysis of 587 patients undergoing endoscopic surgery for pituitary macroadenoma

PURPOSE

Vision loss following surgery for pituitary adenoma is poorly described in the literature and cannot be reliably predicted with current prognostic models. Detailed characterization of this population is warranted to further understand the factors that predispose a minority of patients to post-operative vision loss.

MATERIALS AND METHODS

The medical records of 587 patients who underwent endoscopic transsphenoidal surgery at the Mount Sinai Medical Centre between January 2013 and August 2018 were reviewed. Patients who experienced post-operative vision deterioration, defined by reduced visual acuity, worsened VFDs, or new onset of blurry vision, were identified and analysed.

RESULTS

Eleven out of 587 patients who received endoscopic surgery for pituitary adenoma exhibited post-operative vision deterioration. All eleven patients presented with preoperative visual impairment (average duration of 13.1 months) and pre-operative optic chiasm compression. Seven patients experienced visual deterioration within 24 h of surgery. The remaining four patients experienced delayed vision loss within one month of surgery. Six patients had complete blindness in at least one eye, one patient had complete bilateral blindness. Four patients had reduced visual acuity compared with preoperative testing, and four patients reported new-onset blurriness that was not present before surgery. High rates of graft placement (10/11 patients) and opening of the diaphragma sellae (9/11 patients) were found in this series. Four patients had hematomas and four patients had another significant post-operative complication.

CONCLUSIONS

While most patients with pituitary adenoma experience favourable ophthalmological outcomes following endoscopic transsphenoidal surgery, a subset of patients exhibit post-operative vision deterioration. The present study reports surgical and disease features of this population to further our understanding of factors that may underlie vision loss following pituitary adenoma surgery. Graft placement and opening of the diaphragma sellae may be important risk factors in vision loss following ETS and should be an area of future investigation.

Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and poor functional outcomes, largely because there are no evidence-based treatment options for this devastating disease process. In the past decade, a number of minimally invasive surgeries have emerged to address this issue, one of which is endoscopic evacuation. Stereotactic ICH Underwater Blood Aspiration (SCUBA) is a novel endoscopic evacuation technique performed in a fluid-filled cavity using an aspiration system to provide an additional degree of freedom during the procedure. The SCUBA procedure utilizes a suction device, endoscope, and sheath and is divided into two phases. The first phase involves maximal aspiration and minimal irrigation to decrease clot burden. The second phase involves increasing irrigation for visibility, decreasing aspiration strength for targeted aspiration without disturbing the cavity wall, and cauterizing any bleeding vessels. Using the endoscope and aspiration wand, this technique aims to maximize hematoma evacuation while minimizing collateral damage to the surrounding brain. Advantages of the SCUBA technique include the use of a low-profile endoscopic sheath minimizing brain disruption and improved visualization with a fluid-filled cavity rather than an air-filled one.

Teaching quality in neurosurgery: quantitating outcomes over time

OBJECTIVE

High-quality neurosurgery resident training is essential to developing competent neurosurgeons. Validated formative tools to assess faculty teaching performance exist, but are not used widely among Accreditation Council for Graduate Medical Education (ACGME) residency programs in the United States. Furthermore, their longer-term impact on teaching performance improvement and educational outcomes remains unclear. The goal of this study was to assess the impact of implementing an evaluation system to provide faculty with feedback on teaching performance in a neurosurgery residency training program over a 4-year period.

METHODS

The authors performed a prospective cohort study in which a modified version of the System for Evaluation of Teaching Qualities (SETQ) instrument was administered to neurosurgical trainees in their department regularly every 6 months. The authors analyzed subscale score dynamics to identify the strongest correlates of faculty teaching performance improvement. ACGME program survey results and trainee performance on written board examinations were compared for the 3 years before and after SETQ implementation.

RESULTS

The overall response rate among trainees was 91.8%, with 1044 surveys completed for 41 faculty. Performance scores improved progressively from cycle 1 to cycle 6. The strongest correlate of overall performance was providing positive feedback to trainees. Compared to the 3 years prior, the 3 years following SETQ implementation saw significant increases in written board examination and ACGME resident survey scores compared to the national mean.

CONCLUSIONS

Implementation of SETQ was associated with significant improvements in faculty teaching performance as judged by trainees over a 4-year period, and guided curricular changes in the authors' training program that resulted in improved educational outcomes.

Time to Evacuation and Functional Outcome After Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation

BACKGROUND AND PURPOSE

We present a retrospective analysis of patients who underwent minimally invasive endoscopic intracerebral hemorrhage (ICH) evacuation to identify variables that were associated with long-term outcome.

METHODS

Minimally invasive endoscopic ICH evacuation was performed on patients with supratentorial ICH who fit prespecified clinical inclusion and exclusion criteria. Demographic, clinical, and radiographic factors previously demonstrated to impact functional outcome in ICH were included in a univariate analysis to identify factors associated with favorable outcome (modified Rankin Scale score, 0-3) at 6 months. Factors associated with a favorable outcome in the univariate analysis (P≤0.20) were included in a multivariate logistic regression analysis with the same dependent variable.

RESULTS

Ninety patients underwent MIS endoscopic ICH evacuation within 72 hours of ictus. In a multivariate analysis, factors associated with good long-term functional outcome included time to evacuation (per hour; OR, 0.95 [95% CI, 0.92-0.98], P=0.004), age (per decade, odds ratio [OR], 0.49 [95% CI, 0.28-0.77], P=0.005), presence of intraventricular hemorrhage (OR, 0.15 [95% CI, 0.04-0.47], P=0.002), and lobar location (OR, 18.5 [95% CI, 4.5-103], P=0.0005). Early evacuation was not associated with an increased risk of rebleeding.

CONCLUSIONS

Young age, lack of intraventricular hemorrhage, lobar location, and time to evacuation were independently associated with good long-term functional outcome in patients undergoing minimally invasive endoscopic ICH evacuation. The OR for time to evacuation suggests that for each additional hour, there was a 5% reduction in the odds of achieving a favorable outcome.

Advanced Techniques for Endoscopic Intracerebral Hemorrhage Evacuation: A Technical Report With Case Examples

BACKGROUND

Multiple surgical techniques to perform minimally invasive intracerebral hemorrhage (ICH) evacuation are currently under investigation. The use of an adjunctive aspiration device permits controlled suction through an endoscope, minimizing collateral damage from the access tract. As with increased experience with any new procedure, performance of endoscopic minimally invasive ICH evacuation requires development of a unique set of operative tenets and techniques.

OBJECTIVE

To describe operative nuances of endoscopic minimally invasive ICH evacuation developed at a single center over an experience of 80 procedures.

METHODS

Endoscopic minimally invasive ICH evacuation was performed on 79 consecutive eligible patients who presented a single Health System between March 2016 and May 2018. We summarize 4 core operative tenets and 4 main techniques used in 80 procedures.

RESULTS

A total of 80 endoscopic minimally invasive ICH evacuations were performed utilizing the described surgical techniques. The average preoperative and postoperative volumes were 49.5 mL (standard deviation [SD] 31.1 mL, interquartile range [IQR] 30.2) and 5.4 mL (SD 9.6, mL IQR 5.1), respectively, with an average evacuation rate of 88.7%. All cause 30-d mortality was 8.9%.

CONCLUSION

As experience builds with endoscopic minimally invasive ICH evacuation, academic discussion of specific surgical techniques will be critical to maximizing its safety and efficacy.

Giant chondrosarcoma of the falx in an adolescent: A case report

Background:

Intracranial chondrosarcomas are slowly growing malignant cartilaginous tumors that are especially rare in adolescents.

Case Description:

A 19-year-old woman with no medical history presented with symptoms of intermittent facial twitching and progressive generalized weakness for 6 months. The patient’s physical examination was unremarkable. Imaging revealed a large bifrontal mass arising from the falx cerebri, with significant compression of both cerebral hemispheres and downward displacement of the corpus callosum. The patient underwent a bifrontal craniotomy for gross total resection of tumor. Neuropathologic examination revealed a bland cartilaginous lesion most consistent with low-grade chondrosarcoma. Her postoperative course was uneventful, and she was discharged to home on postoperative day 3.

Conclusion:

This is an unusual case of an extra-axial, non-skull base, low-grade chondrosarcoma presenting as facial spasm in an adolescent patient.

USP8 and TP53 Drivers are Associated with CNV in a Corticotroph Adenoma Cohort Enriched for Aggressive Tumors

CONTEXT

Pituitary corticotroph adenomas are rare tumors that can be associated with excess adrenocorticotropin (ACTH) and adrenal cortisol production, resulting in the clinically debilitating endocrine condition Cushing disease. A subset of corticotroph tumors behave aggressively, and genomic drivers behind the development of these tumors are largely unknown.

OBJECTIVE

To investigate genomic drivers of corticotroph tumors at risk for aggressive behavior.

DESIGN

Whole-exome sequencing of patient-matched corticotroph tumor and normal deoxyribonucleic acid (DNA) from a patient cohort enriched for tumors at risk for aggressive behavior.

SETTING

Tertiary care center.

PATIENTS

Twenty-seven corticotroph tumors from 22 patients were analyzed. Twelve tumors were macroadenomas, of which 6 were silent ACTH tumors, 2 were Crooke's cell tumors, and 1 was a corticotroph carcinoma.

INTERVENTION

Whole-exome sequencing.

MAIN OUTCOME MEASURE

Somatic mutation genomic biomarkers.

RESULTS

We found recurrent somatic mutations in USP8 and TP53 genes, both with higher allelic fractions than other somatic mutations. These mutations were mutually exclusive, with TP53 mutations occurring only in USP8 wildtype (WT) tumors, indicating they may be independent driver genes. USP8-WT tumors were characterized by extensive somatic copy number variation compared with USP8-mutated tumors. Independent of molecular driver status, we found an association between invasiveness, macroadenomas, and aneuploidy.

CONCLUSIONS

Our data suggest that corticotroph tumors may be categorized into a USP8-mutated, genome-stable subtype versus a USP8-WT, genome-disrupted subtype, the latter of which has a TP53-mutated subtype with high level of chromosome instability. These findings could help identify high risk corticotroph tumors, namely those with widespread CNV, that may need closer monitoring and more aggressive treatment.

Interhospital Transfer of Intracerebral Hemorrhage Patients Undergoing Minimally Invasive Surgery: The Experience of a New York City Hospital System

OBJECTIVE

The impact of interhospital transfer (IHT) on outcomes of patients with intracerebral hemorrhage (ICH) has not been well studied. We seek to describe the protocolized IHT and systems of care approach of a New York City hospital system, where ICH patients undergoing minimally invasive surgery (MIS) are transferred to a dedicated ICH center.

METHODS

We retrospectively reviewed 100 consecutively admitted patients with spontaneous ICH. We gathered information on demographics, variables related to IHT, clinical and radiographic characteristics, and details about the clinical course and outpatient follow-up. We grouped patients into 2 cohorts: those admitted through IHT and those directly admitted through the emergency department. Primary outcome was good functional outcome at 6 months, defined as modified Rankin Scale score 0-3.

RESULTS

Of 100 patients, 89 underwent IHT and 11 were directly admitted. On multivariable analysis, there were no significant differences in 6-month functional outcome between the 2 cohorts. All transfers were managed by a system-wide transfer center and 24/7 hotline for neuroemergencies. An ICH-specific IHT protocol was followed, in which a neurointensivist provided recommendations for stabilizing patients for transfer. Average transfer time was 199.7 minutes and average distance travelled was 13.6 kilometers.

CONCLUSIONS

In our hospital system, a centralized approach to ICH management and a dedicated ICH center increased access to specialist services, including MIS. Most patients undergoing MIS were transferred from outside hospitals, which highlights the need for additional studies and descriptions of experiences to further elucidate the impact of and best protocols for the IHT of ICH patients.

"Staying Home"-Early Changes in Patterns of Neurotrauma in New York City During the COVID-19 Pandemic

OBJECTIVE

New York City is the epicenter of the novel coronavirus disease 2019 (COVID-19) pandemic in the United States. Traumatic brain injury accounts for a significant proportion of admissions to our trauma center. We sought to characterize the effect of the pandemic on neurotraumas, given the cancellation of nonessential activities during the crisis.

METHODS

Retrospective and prospective reviews were performed from November 2019 to April 2020. General demographics, clinical status, mechanism of trauma, diagnosis, and treatment instituted were recorded. We dichotomized the data between pre-COVID-19 (before 1 March) and COVID-19 periods and compared the differences between the 2 groups. We present the timeline of events since the beginning of the crisis in relation to the number of neurotraumas.

RESULTS

A total of 150 patients composed our cohort with a mean age of 66.2 years (standard deviation ±18.9), and 66% were male. More males sustained neurotrauma in the COVID-19 period compared with the pre-COVID-19 (60.4% vs. 77.6%, P = 0.03). The most common mechanism of trauma was mechanical fall, but it was observed less frequently compared with the pre-COVID-19 period (61.4% vs. 40.8; P = 0.03). Subdural hematoma, traumatic subarachnoid hemorrhage, and intracerebral contusion accounted for the most common pathologies in both periods. Nonoperative management was selected for most patients (79.2 vs. 87.8%, P = 0.201) in both periods.

CONCLUSIONS

A decrease in the frequency of neurotraumas was observed during the COVID-19 crisis concomitant with the increase in COVID-19 patients in the city. This trend began after the cancellation of nonessential activities and implementation of social distancing recommendations.

By the Numbers Analysis of Effect of COVID-19 on a Neurosurgical Residency at the Epicenter

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 pandemic has created challenges to neurosurgical patient care. Despite editorials evaluating neurosurgery responses to 2019 novel coronavirus disease (COVID-19), data reporting effects of COVID-19 on neurosurgical case volume, census, and resident illness are lacking. The aim of this study was to present a real-world analysis of neurosurgical volumes, resident deployment, and unique challenges encountered during the severe acute respiratory syndrome coronavirus 2 outbreak peak in New York City.

METHODS

Daily census and case volume data were prospectively collected throughout the severe acute respiratory syndrome coronavirus 2 outbreak in spring 2020. Neurosurgical census was compared against COVID-19 system-wide data. Neurosurgical cases during the crisis were analyzed and compared with 7-week periods from 2019 and early 2020. Resident deployment and illness were reviewed.

RESULTS

From March 16, 2020, to May 5, 2020, residents participated in 72 operations and 69 endovascular procedures compared with 448 operations and 253 endovascular procedures from January 2020 to February 2020 and 530 operations and 340 endovascular procedures from March 2019 to May 2019. There was a 59% reduction in neurosurgical census during the outbreak (median 24 patients, 2.75 average total cases daily). COVID-19 neurosurgical admissions peaked in concert with the system-wide pandemic. Three residents demonstrated COVID-19 symptoms (no hospitalizations occurred) for a total 24 workdays lost (median 7 workdays).

CONCLUSIONS

These data provide real-world guidance on neurosurgical infrastructure needs during a COVID-19 outbreak. While redeployment to support the COVID-19 response was required, a significant need remained to continue to provide critical neurosurgical service.

The Role of Advanced Endoscopic Resection of Diverse Skull Base Malignancies: Technological Analysis during an 8-Year Single Institutional Experience

Background Resection of skull base malignancies poses complex pathological and treatment-related morbidities. Recent technological advancements of endoscopic endonasal surgery (EES) offer the ability to reexamine traditional treatment paradigms with endoscopic procedures. The utility of EES was quantitatively examined in a longitudinal series with attention to morbidities and postoperative outcomes.

Methods A single-center retrospective review was performed of all malignant sinonasal tumors from 2010 to 2018. Patients with purely EES were selected for analysis. Disease features, resection extent, complications, adjuvant treatment, recurrence, and survivability were assessed. Despite the mixed pathological cohort, analysis was performed to identify technical aspects of resection.

Results A total of 68 patients (47.6% males and 52.4% females, average age: 60.3 years) were included. A diversity of histotypes included clival chordoma (22.1%), olfactory neuroblastoma (14.7%), squamous cell carcinoma (11.8%), and adenoid cystic carcinoma (11.8%). Gross total resection (GTR) was achieved in 83.8% of cases. Infection (4.4%) and cerebrospinal fluid leak (1.5%) were the most common postoperative complications. Total 46 patients (67.6%) underwent adjuvant treatment. The average time between surgery and initiation of adjunctive surgery was 55.7 days.

Conclusion In our 8-year experience, we found that entirely endoscopic resection of mixed pathology of malignant skull base tumors is oncologically feasible and can be accomplished with high GTR rates. There may be a role for EES to reduce operative morbidity and attenuate time in between surgery and adjuvant treatment, which can be augmented through recent mixed reality platforms. Future studies are required to systematically compare the outcomes with those of open surgical approaches.

COVID-19 and Decompressive Hemicraniectomy for Acute Ischemic Stroke

Young patients with malignant cerebral edema have been shown to benefit from early decompressive hemicraniectomy. The impact of concomitant infection with coronavirus disease 2019 (COVID-19) and how this should weigh in on the decision for surgery is unclear.

Surgical outcomes in patients with endoscopic versus transcranial approach for skull base malignancies: a 10-year institutional experience

Object: The authors performed an extensive comparison between patients treated with open versus an endoscopic approach for skull base malignancy with emphasis on surgical outcomes.Methods: A single-institution retrospective review of 60 patients who underwent surgery for skull base malignancy between 2009 and 2018 was performed. Disease features, surgical resection, post-operative morbidities, adjuvant treatment, recurrence, and survival rates were compared between 30 patients who received purely open surgery and 30 patients who underwent purely endoscopic resection for a skull base malignancy.Results: Of the 60 patients with skull base malignancy, 30 underwent open resection and 30 underwent endoscopic resection. The most common hisotype for endoscopic resection was squamous cell carcinoma (26.7%), olfactory neuroblastoma (16.7%), and sarcoma (10.0%), and 43.3%, 13.3%, and 10.0% for the open resection cohort, respectively. There were no statistical differences in gross total resection, surgical-associated cranial neuropathy, or ability to achieve negative margins between the groups (p > 0.1, all comparisons). Patients who underwent endoscopic resection had shorter surgeries (320.3 ± 158.5 minutes vs. 495.3 ± 187.6 minutes (p = 0.0003), less intraoperative blood loss (282.2 ± 333.6 ml vs. 696.7 ± 500.2 ml (p < 0.0001), and shorter length of stay (3.5 ± 3.7 days vs. 8.8 ± 6.0 days (p < 0.0001). Additionally, patients treated endoscopically initiated adjuvant radiation treatment more quickly (48.0 ± 20.3 days vs. 72.0 ± 20.5 days (p = 0.01).Conclusions: An endoscopic endonasal approach facilitates a clinically meaningful improvement in surgical outcomes for skull base malignancies.

SAT-LB49 Persistent vs Recurrent Cushing’s Disease Diagnosed Four Weeks Post-Partum

Background: Cushing’s disease (CD) recurrence in pregnancy has previously been described and is thought to be associated with predictable estradiol fluctuations during gestation. CD recurrence in the immediate post-partum period has been reported once, but never in a patient with documented dormant disease during pregnancy.Clinical Case: A 30 year old woman with recently diagnosed pre-diabetes presented with weight gain, dorsal hump, depression, oligomenorrhea, and lower extremity weakness. Diagnostic tests were consistent with CD. Results included: three elevated midnight salivary cortisols: 0.33, 1.38 and 1.10 ug/dL (<0.010 - 0.090); 1-mg dexamethasone suppression test (DST) with cortisol 14 ug/dL (<1.8); elevated 24-hr urine cortisol 825 ug/24 hr (6-42); and ACTH 35 pg/mL (7.2-63.3). MRI of the pituitary gland revealed a left 4mm focal lesion. After transsphenoidal resection (TSA), day 1, 2, and 3 morning cortisol values were 18, 5, and 2 ug/dL, respectively. Pathology did not show a definitive pituitary neoplasm. She was rapidly titrated off hydrocortisone (HC) by six weeks post-resection. Her symptoms steadily improved. She resumed normal menses and conceived unexpectedly around 3 months post-TSA. She complained of severe fatigue in her late 2^nd trimester. Given low 24-hr urine cortisol of 15 ug/24 hr at 36 weeks gestation, she was started on HC. She was induced at 40 weeks gestation for oligohydramnios and subsequently delivered a healthy baby boy. HC was discontinued immediately after delivery. Around four weeks post-partum she developed symptoms concerning for CD. Diagnostic tests showed elevated midnight salivary cortisol of 0.206 and 0.723 ug/dL and 24-hour urine cortisol of 400 ug/24 hr. MRI pituitary illustrated a 3mm adenoma in the left posterior gland which was thought to represent growth of residual tumor not clearly seen on post-op MRI. During repeat TSA, a discrete lesion was found and resected. Pathology confirmed corticotroph adenoma with MIB-1 < 3%. Post-operative day 1, 2, and 3 cortisol levels were 26, 10 and 2.8 ug/dL, respectively. She was tapered off HC within one month. Her symptoms improved only slightly and she continued to report weight gain, muscle weakness, and fatigue. Three months after repeat TSA, biochemical data showed 1 out of 2 midnight salivary cortisols elevated at 0.124 ug/dL and elevated urine cortisol of 76 ug/24 hr. MRI pituitary demonstrated a 3 x 5 mm left enhancement, concerning for residual or enlarged persistent tumor. Conclusion: We describe the first report of recurrent CD that was quiescent during pregnancy, and subsequently diagnosed in the immediate post-partum period. Treatment options for persistent or recurrent CD include aggressive surgical resection, radiation and/or medical therapy. In the context of additional family planning for this otherwise healthy, reproductive-age woman, ideal management options remain uncertain.

Brain Metastases from Biliary Tract Cancers: A Case Series and Review of the Literature in the Genomic Era

BACKGROUND

Biliary tract cancers (BTCs) are highly fatal malignancies that make up less than 1% of all cancers. BTC is often diagnosed at an unresectable stage; surgical resection remains the only definitive treatment. Brain metastases (BMs) from BTC are extremely rare, and few studies on patients with BMs from BTC exist. The aim of this study was to identify clinical characteristics associated with poor prognosis for patients with BMs from BTC.

MATERIALS AND METHODS

We performed a retrospective review of electronic medical records for patients with BMs from BTC managed at Mount Sinai Hospital from 2000 to 2017. Data on patient characteristics, magnetic resonance imaging findings, treatment regimens, and clinical outcomes were analyzed.

RESULTS

We identified 1,910 patients with BTC. Nine patients developed BMs, with an incidence of 0.47%. Of these nine patients, six had intrahepatic cholangiocarcinoma, two had extrahepatic cholangiocarcinoma, and one had gallbladder cancer. Six (66.7%) patients had one BM, one (11.1%) patient had two BMs, and two (22.2%) patients had three or more BMs. Four (44.4%) patients underwent BM resection, and seven (77.8%) received BM radiation. Median overall survival from time of BM diagnosis was 3.8 months (95% confidence interval 0.1-16.9).

CONCLUSION

Development of BMs from BTC is rare; however, prognosis is less than 4 months. BM diagnosis can occur within 2 years of primary diagnosis. As targeted therapeutics emerge, future studies ought to focus on identifying genomic BM markers associated with BTC subtypes.

IMPLICATIONS FOR PRACTICE

In the largest retrospective study of biliary tract cancer brain metastases, the clinical presentation and outcomes are reported of nine patients with an extremely rare clinical entity. The genomic literature and potential therapeutic targets for these patients with limited treatment options is comprehensively and exhaustively discussed.

Neurosurgical activity during COVID-19 pandemic: an experts' opinion from China, South Korea, Italy, the USA, Colombia, and the UK

BACKGROUND

More than a million and a half people are infected worldwide with more than 90,000 casualties. The ongoing COVID-19 pandemic is radically altering both socio-economic and health care scenarios.

METHODS

On April 4th, 2020, at 13:30 CET, a webinar was broadcasted, organized by Global Neuro and supported by WFNS. Expert neurosurgeons from six different countries (China, Italy, South Korea, the USA, Colombia, and the UK) reported on the impact of the COVID-19 pandemic on their health care systems and neurosurgical activity.

RESULTS

The first part focused on the epidemiology until that date. The USA were the most affected State with 450,000 cases, followed by Italy (140,000 cases and 19,000 casualties), China (83,305 cases and 3345 have died), South Korea (10,156 cases with 177 casualties), the UK (38,168 cases and 3605 deaths) and Colombia (1267 cases and 25 deaths). The second part concerned Institution and staff reorganization. In every country all surgical plans have been modified. The third part was about neurosurgical practice during the COVID-19 pandemic. The fourth and last part touched upon how to perform safe surgery and re-start after the pandemic.

CONCLUSIONS

In general, the pandemic scenario was presented as a thought-provoking challenge in all countries which requires tireless efforts for both maintaining emergency and elective neurosurgical procedures.

Analysis of 7-tesla diffusion-weighted imaging in the prediction of pituitary macroadenoma consistency

OBJECTIVE

Endoscopic surgery is an effective treatment strategy for pituitary adenomas; however, intrinsic tumor properties such as tumor consistency can challenge or preclude gross-total resection. Preoperative characterization of tumor consistency may help to guide the surgical approach and to predict the extent of resection that is possible. Advanced radiological modalities such as 7T diffusion-weighted imaging (DWI) may be useful in probing biological tissue properties of pituitary adenomas. The objective of the present study was to examine 7T DWI as a novel method of measuring the consistency of pituitary adenomas.

METHODS

Thirteen patients with pituitary macroadenomas underwent 7T MRI, including a DWI image acquisition. Tumor apparent diffusion coefficient (ADC) was normalized to the adjacent temporal gray matter ADC. All patients underwent resection, and a single neurosurgeon blinded to ADC values rated tumor firmness from 1 (least firm) to 5 (most firm) using objective criteria. The tumor specimens were evaluated histopathologically for cellularity, collagen content, and vascularity by a neuropathologist who was also blinded to ADC values. The tumor ADC was correlated with intraoperative consistency rating, histopathology, and extent of resection. Receiver operating characteristic (ROC) curve analyses were performed to identify thresholds to predict tumor consistency.

RESULTS

Corrected ADC values were significantly correlated with both tumor firmness (r = -0.60, p = 0.029) and the extent of trichrome staining (r = -0.72, p = 0.009) such that greater ADC values were associated with both decreased tumor firmness and decreased collagen staining. Correlations between ADC values and tumor vascularity were not significant (r = -0.09, p = 0.78). Corrected ADC values in totally resected tumors (1.54) were greater than those in subtotally resected tumors (0.85) (p = 0.02), and ADC values were greater with moderate tumor cellularity (1.51) than with high tumor cellularity (0.8) (p = 0.035). There was a trend-level association for partial resections to exhibit greater tumor firmness rating (3 vs 1.7; p = 0.051). Finally, the degree of trichrome staining positively correlated with tumor firmness (r = 0.60, p = 0.04). The optimal threshold for predicting intraoperative consistency rating was an ADC ratio of 0.87 (sensitivity 80%, specificity 100%, area under the curve [AUC] 0.90; p = 0.043). The optimal cutoff for distinguishing the extent of resection was 1.19 (sensitivity 85.7%, specificity 83.3% AUC 0.833; p = 0.046).

CONCLUSIONS

The authors' results suggest that a high-resolution ADC of pituitary adenomas is a sensitive measure of tumor consistency. 7T DWI may hold clinical value in the preoperative workup and surgical management of patients with pituitary macroadenomas.

Benefit of Endoscopic Surgery in the Management of Acute Invasive Skull Base Fungal Rhinosinusitis

Objective  This article aims to characterize 14 patients who underwent purely endoscopic surgical debridement of acute invasive skull base fungal rhinosinusitis, and to evaluate postoperative outcomes and risk for recurrence. Design  Retrospective cohort study. Setting  Tertiary single-institution neurosurgery department. Participants  We performed a retrospective analysis of all patients with skull base fungal infections treated with a purely endoscopic surgical approach at Mount Sinai Hospital from 1998 to 2018. Main Outcome Measures  Clinical presentation, number of recurrences, and mortality rate. Results  The most common underlying medical comorbidities were hematologic malignancy in 8 (57.1%) patients and poorly controlled diabetes mellitus in 7 (50%) patients. Presenting symptoms included headache (50%), eye pain (35.7%), facial pain (28.6%), visual changes (21.4%), and nasal congestion (14.3%). The fungal organisms identified on culture were Aspergillus (42.9%), Mucorales (28.6%), Fusarium (14.3%), Penicillium (7.1%), and unspecified (7.1%). Eight (57.1%) patients developed recurrence and required multiple surgical debridements. Patients who had only a hematologic malignancy were more likely to require multiple surgical debridements compared with those who did not have a hematologic malignancy or those who had both hematologic malignancy and underlying diabetes mellitus ( p  = 0.03). The mortality rate from surgery was 42.9%. Conclusion  Surgical endoscopic intervention is an option for definitive management of acute invasive skull base fungal rhinosinusitis; however, postoperative mortality and risk of recurrence requiring additional surgical interventions remains high. Patients with hematologic malignancy may be more susceptible to recurrent infection requiring multiple surgical debridements. We recommend early aggressive multimodal treatment. Multiple debridements may be warranted in most cases; close clinical surveillance is needed during neurosurgical intervention.

Long-term functional outcome following minimally invasive endoscopic intracerebral hemorrhage evacuation

Background and purpose

Preclinical studies suggest that clot removal may mitigate primary and secondary brain injury following intracerebral hemorrhage (ICH). Although the MISTIE trial did not demonstrate an overall outcome benefit, it did demonstrate outcome benefit from effective reduction of clot burden. Minimally invasive endoscopic ICH evacuation may provide an alternative option for clot evacuation.

Methods

Patients presenting to a single healthcare system from December 2015 to October 2018 with supratentorial spontaneous ICH were evaluated for minimally invasive endoscopic evacuation. Inclusion and exclusion criteria were prospectively established by a multidisciplinary group in the healthcare system. The prespecified primary analysis was the proportion of patients with modified Rankin Score (mRS) 0–3 at 6 months.

Results

One hundred patients met the inclusion and exclusion criteria and underwent minimally invasive endoscopic ICH evacuation. The mean (SD) hematoma size was 49.7 (30.6) mL, the mean (SD) evacuation percentage was 88.2 (20.3)%, and 86% of patients had postoperative residual hematoma ≤15 mL. At 6 months the proportion of patients with an mRS of 0–3 was 46%.

Conclusions

This study suggests that minimally invasive endoscopic ICH evacuation may produce favorable long-term functional outcomes. Further evaluation of this technique in a randomized clinical trial is necessary.

Correlation of spontaneous and traumatic anterior skull base CSF leak flow rates with fluid pattern on early, delayed, and subtraction volumetric extended echo train T2-weighted MRI

OBJECTIVE

CSF leakage is a potentially fatal condition that may result when a skull base dural defect permits CSF communication between the cranial vault and sinonasal cavities. Flow rate is an important property of CSF leaks that can contribute to surgical decision-making and predispose patients to complications and inferior outcomes. Noninvasive preoperative prediction of the leak rate is challenging with traditional diagnostic tools. The present study compares fluid configurations on early and late volumetric extended echo train T2-weighted MRI by using image tracings and sequence subtraction as a novel method of quantifying CSF flow rate, and it correlates radiological results with intraoperative findings and clinical outcomes.

METHODS

A total of 45 patients met inclusion criteria for this study and underwent 3-T MRI. Imaging sequences included two identical CUBE T2 (vendor trade name for volumetric extended echo train T2) acquisitions at the beginning and end of the scanning session, approximately 45 minutes apart. Twenty-five patients were confirmed to have definitive spontaneous or traumatic anterior skull base CSF leaks. Semiautomated volumetric segmentation of CSF intensity was performed on both CUBE data sets by using 3D-Slicer software, and volumes were subtracted to obtain accumulated CSF volume. These imaging-derived fluid accumulations were correlated with high- or low-flow states, as well as ultimate treatment outcomes including recurrences.

RESULTS

Of the 45 patients, 25 (55.6%) had definitive evidence of CSF leakage, and 22 (88%) of these underwent surgical repair. Patients with high-flow CSF leaks had higher early (4.058 cm3 vs 0.982 cm3, p = 0.04), late (4.58 cm3 vs 1.096 cm3, p = 0.04), and accumulated (0.53 cm3 vs 0.11 cm3, p = 0.01) fluid volume measurements than patients with low-flow leaks. The 5 (22.7%) patients who exhibited postoperative CSF leak recurrence had significantly greater early (6.30 cm3 vs 1.23 cm3, p = 0.008) and late (6.87 cm3 vs 1.45 cm3, p = 0.008) volumes. Accumulated volume was not significantly greater in patients with leak recurrence (0.58 cm3 vs 0.22 cm3, p = 0.07). Early, late, and accumulated volumes were significantly correlated with postoperative hospital stay as well as duration of postoperative lumbar drain placement (p < 0.05 for all measures).

CONCLUSIONS

High-resolution CUBE T2 MRI, coupled with precise volumetric segmentation and subtraction of sinonasal hyperintensity, not only demonstrated predictive value in differentiating low- and high-flow CSF leaks, but also correlated with postoperative complications such as leak recurrence. These findings may be useful in the clinical workup and neurosurgical management of patients with skull base CSF leaks.

Navigation-Linked Heads-Up Display in Intracranial Surgery: Early Experience

BACKGROUND

The use of intraoperative navigation during microscope cases can be limited when attention needs to be divided between the operative field and the navigation screens. Heads-up display (HUD), also referred to as augmented reality, permits visualization of navigation information during surgery workflow.

OBJECTIVE

To detail our initial experience with HUD.

METHODS

We retrospectively reviewed patients who underwent HUD-assisted surgery from April 2016 through April 2017. All lesions were assessed for accuracy and those from the latter half of the study were assessed for utility.

RESULTS

Seventy-nine patients with 84 pathologies were included. Pathologies included aneurysms (14), arteriovenous malformations (6), cavernous malformations (5), intracranial stenosis (3), meningiomas (27), metastasis (4), craniopharygniomas (4), gliomas (4), schwannomas (3), epidermoid/dermoids (3), pituitary adenomas (2) hemangioblastoma (2), choroid plexus papilloma (1), lymphoma (1), osteoblastoma (1), clival chordoma (1), cerebrospinal fluid leak (1), abscess (1), and a cerebellopontine angle Teflon granuloma (1). Fifty-nine lesions were deep and 25 were superficial. Structures identified included the lesion (81), vessels (48), and nerves/brain tissue (31). Accuracy was deemed excellent (71.4%), good (20.2%), or poor (8.3%). Deep lesions were less likely to have excellent accuracy (P = .029). HUD was used during bed/head positioning (50.0%), skin incision (17.3%), craniotomy (23.1%), dural opening (26.9%), corticectomy (13.5%), arachnoid opening (36.5%), and intracranial drilling (13.5%). HUD was deactivated at some point during the surgery in 59.6% of cases. There were no complications related to HUD use.

CONCLUSION

HUD can be safely used for a wide variety of vascular and oncologic intracranial pathologies and can be utilized during multiple stages of surgery.

Primary visual cortical thickness in correlation with visual field defects in patients with pituitary macroadenomas: a structural 7-Tesla retinotopic analysis

OBJECTIVE

Vision loss remains a debilitating complication of pituitary adenomas, although there is considerable variability in visual impairment before and after decompression surgery. Growing evidence suggests secondary damage to remote visual structures may contribute to vision loss in patients with chiasmatic compression. The present study leverages ultrahigh field 7-T MRI to study the retinotopic organization of the primary visual cortex (V1), and correlates visual defects with cortical thinning in V1 to characterize consequences of pituitary adenomas on the posterior visual system.

METHODS

Eight patients (4 males and 4 females, mean age 44.3 years) with pituitary adenomas who exhibited chiasmatic compression and visual field defects, as well as 8 matched healthy controls (4 males and 4 females, mean age 43.3 years), were scanned at 7-T MRI for this prospective study. Whole-brain cortical thickness was calculated using an automated algorithm. A previously published surface-based algorithm was applied to associate the eccentricity and polar angle with each position in V1. Cortical thickness was calculated at each point in the retinotopic organization, and a cortical thickness ratio was generated against matched controls for each point in the visual fields. Patients with adenoma additionally underwent neuroophthalmological examination including 24-2 Humphrey automated visual field perimetry. Pattern deviation (PD) of each point in the visual field, i.e., the deviation in point detection compared with neurologically healthy controls, was correlated with cortical thickness at corresponding polar and eccentricity angles in V1.

RESULTS

Whole-brain cortical thickness was successfully derived for all patients and controls. The mean tumor volume was 19.4 cm3. The median global thickness of V1 did not differ between patients (mean ± SD 2.21 ± 0.12 cm), compared with controls (2.06 ± 0.13 cm, p > 0.05). Surface morphometry-based retinotopic maps revealed that all 8 patients with adenoma showed a significant positive correlation between PD and V1 thickness ratios (r values ranged from 0.31 to 0.53, p < 0.05). Mixed-procedure analysis revealed that PD = -8.0719 + 5.5873*[Median V1 Thickness Ratio].

CONCLUSIONS

All 8 patients showed significant positive correlations between V1 thickness and visual defect. These findings provide retinotopic maps of localized V1 cortical neurodegeneration spatially corresponding to impairments in the visual field. These results further characterize changes in the posterior visual pathway associated with chiasmatic compression, and may prove useful in the neuroophthalmological workup for patients with pituitary macroadenoma.

First application of 7-T ultra-high field diffusion tensor imaging to detect altered microstructure of thalamic-somatosensory anatomy in trigeminal neuralgia

OBJECTIVE

Trigeminal neuralgia (TN) is a debilitating neurological disease that commonly results from neurovascular compression of the trigeminal nerve (CN V). Although the CN V has been extensively studied at the site of neurovascular compression, many pathophysiological factors remain obscure. For example, thalamic-somatosensory function is thought to be altered in TN, but the abnormalities are inadequately characterized. Furthermore, there are few studies using 7-T MRI to examine patients with TN. The purpose of the present study was to use 7-T MRI to assess microstructural alteration in the thalamic-somatosensory tracts of patients with TN by using ultra-high field MRI.

METHODS

Ten patients with TN and 10 age- and sex-matched healthy controls underwent scanning using 7-T MRI with diffusion tensor imaging. Structural images were segmented with an automated algorithm to obtain thalamus and primary somatosensory cortex (S1). Probabilistic tractography was performed between the thalamus and S1, and the microstructure of the thalamic-somatosensory tracts was compared between patients with TN and controls.

RESULTS

Fractional anisotropy of the thalamic-somatosensory tract ipsilateral to the site of neurovascular compression was reduced in patients (mean 0.43) compared with side-matched controls (mean 0.47, p = 0.01). The mean diffusivity was increased ipsilaterally in patients (mean 6.58 × 10-4 mm2/second) compared with controls (mean 6.15 × 10-4 mm2/second, p = 0.02). Radial diffusivity was increased ipsilaterally in patients (mean 4.91 × 10-4 mm2/second) compared with controls (mean 4.44 × 10-4 mm2/second, p = 0.01). Topographical analysis revealed fractional anisotropy reduction and diffusivity elevation along the entire anatomical S1 arc in patients with TN.

CONCLUSIONS

The present study is the first to examine microstructural properties of the thalamic-somatosensory anatomy in patients with TN and to evaluate quantitative differences compared with healthy controls. The finding of reduced integrity of these white matter fibers provides evidence of microstructural alteration at the level of the thalamus and S1, and furthers the understanding of TN neurobiology.

A Virtual-Reality, 360-Degree Fly-Through of an Arteriovenous Malformation Resection: 2-Dimensional Operative Video

The application of navigation integrated virtual reality (VR) in neurosurgery is an emerging paradigm that may offer improved situational awareness for the surgeon. Here, we present a case of a complex arteriovenous malformation (AVM) with complex venous drainage and observe how VR impacted structural delineation during approach, resection, and overall strategic planning. The patient was a 30-yr-old female with no past medical history who presented with headaches and a generalized tonic clonic seizure. Workup included computed tomography, computed tomography angiography, magnetic resonance imaging, magnetic resonance angiography, and magnetic resonance venography; a high flow right frontal AVM was found. The AVM was safely resected using navigation integrated with VR; careful arterial devascularization preceded resection of the draining veins and then the AVM nidus. Postoperative scans confirmed complete resection of the AVM. This case outlines the application of a current state-of-the-art VR platform to assist the craniotomy for resection of an AVM.