Objective assessment of postural ergonomics in neurosurgery: integrating wearable technology in the operating room

OBJECTIVE

Physical stress associated with the static posture of neurosurgeons over prolonged periods can result in fatigue and musculoskeletal disorders. Objective assessment of surgical ergonomics may contribute to postural awareness and prevent further complications. This pilot study examined the feasibility of using wearable technology as a biofeedback tool to address this gap.

METHODS

Ten neurosurgeons, including 5 attendings (all faculty) and 5 trainees (1 fellow, 4 residents), were recruited and equipped with two wearable sensors attached to the back of their head and their upper back. The sensors collected the average time spent in extended (≤ -10°), neutral (> -10° and < 10°), and flexed (≥ 10°) static postures (undetected activity for more than 10 seconds) during spine and cranial procedures. Feasibility outcomes aimed for more than 70% of accurate data collection. Exploratory outcomes included the comparison of postural variability within and between participants adjusted to their demographics excluding nonrelated surgical activities, and postoperative self-assessment surveys.

RESULTS

Sixteen (80%) of 20 possible recordings were successfully collected and analyzed from 11 procedures (8 spine, 3 cranial). Surgeons maintained a static posture during 52.7% of the active surgical time (mean 1.58 hrs). During spine procedures, all surgeons used an exoscope while standing, leading to a significantly longer time spent in a neutral static posture (p < 0.001, partial η2 = 0.14): attendings remained longer in a neutral static posture (36.4% ± 15.3%) than in the extended (9% ± 6.3%) and flexed (5.7% ± 3.4%) static postures; trainees also remained longer in a neutral static posture (30.2% ± 13.8%) than in the extended (11.1% ± 6.3%) and flexed (11.9% ± 6.6%) static postures. During cranial procedures, surgeons intermittently transitioned between standing/exoscope use and sitting/microscope use, with trainees spending a shorter time in a neutral static posture (16.3% vs 48.5%, p < 0.001) and a longer time in a flexed static posture (18.5% vs 2.7%, p < 0.001) compared with attendings. Additionally, longer cranial procedures correlated with surgeons spending a longer time (r = 0.94) in any static posture (extended, flexed, and neutral), with taller surgeons exhibiting longer periods in flexed and extended static postures (r = 0.86). Postoperative self-assessment revealed that attendings perceived spine procedures as more difficult than trainees (p = 0.029), while trainees found cranial procedures to be of greater difficulty than spine procedures (p = 0.012). Attendings felt more stressed (p = 0.048), less calmed (p = 0.024), less relaxed (p = 0.048), and experienced greater stiffness in their upper body (p = 0.048) and more shoulder pain (p = 0.024) during cranial versus spine procedures.

CONCLUSIONS

Wearable technology is feasible to assess postural ergonomics and provide objective biofeedback to neurosurgeons during spine and cranial procedures. This study showed reproducibility for future comparative protocols focused on correcting posture and surgical ergonomic education.

Cerebrospinal Fluid Drainage in Patients with Acute Spinal Cord Injury: A Multi-Center Randomized Controlled Trial

OBJECTIVE

The secondary phase of spinal cord injury (SCI) is characterized by ischemic injury. Spinal cord perfusion pressure (SCPP), calculated as the difference between mean arterial pressure (MAP) and intrathecal pressure (ITP), has arisen as a therapeutic target for improving outcomes. Cerebrospinal fluid drainage (CSFD) may reduce ITP and thereby increase SCPP. Randomized controlled trial to evaluate the safety and feasibility of CSFD to improve SCPP and outcomes after acute SCI.

METHODS

Inclusion criteria included acute cervical SCI within 24 hours of presentation. All patients received lumbar drain placement and appropriate decompressive surgery. Patients randomized to the control group received MAP elevation only. Patients in the experimental group received MAP elevation and CSFD to achieve ITP < 10 mmHg for 5 days. ITP and MAP were recorded hourly. Adverse events were documented and patients underwent functional assessments at enrollment, 72 hours, 90 days, and 180 days post-injury.

RESULTS

Eleven patients were enrolled; 4 were randomized to receive CSFD. CSFD patients had a mean ITP of 5.3±2.5 mmHg vs 15±3.0 mmHg in the control group. SCPP improved significantly, from 77±4.5 mmHg in the control group to 101±6.3 mmHg in the CSFD group (p<0.01). Total motor scores improved by 15±8.4 and 57±24 points in the control and CSFD groups, respectively, over 180 days. No adverse events were attributable to CSFD.

CONCLUSIONS

CSFD is a safe, effective mechanism for reducing ITP and improving SCPP in the acute period post-SCI. The favorable safety profile and preliminary efficacy should help drive recruitment in future studies.

Combined Transcranial and Endoscopic Endonasal Approach for Resection of a Complex Sinonasal Squamous Cell Carcinoma: Two-Dimensional Operative Video

Sinonasal squamous cell carcinoma (SCC) is a rare head-and-neck neoplasm that has a propensity to locally invade vital structures. Currently, the combination of surgical resection and radiation remains the optimal treatment.1 However, the extent of disease burden and involvement of surrounding anatomy may make these inoperable. Here, we demonstrate the successful application of multidisciplinary approach for surgical resection of a large, complex SCC lesion centered at the superior nasal cavity with extension into the eye orbits and brain. A two-step approach was performed; transcribiform, endoscopic piecemeal resection with reconstruction of the skull base, followed by a bifrontal craniotomy. Reconstruction was achieved using an inlay of DuraMatrix allograft (Stryker Inc., Kalamzoo, Michigan, United States) followed by an inlay of AlloDerm (Allergan Inc., Irvine, California, United States), anchored anteriorly and posteriorly with wide wings placed over the respective orbital roofs. Major steps include (1) a summary of the patient presentation and preoperative imaging, (2) resection of the tumor endonasally, (3) resection of the tumor intracranially from a bifrontal craniotomy, and (4) a review of the postoperative imaging. The patient tolerated the procedure (Fig. 1) well, returned to his baseline with no new neurologic deficits, and was placed on 6-week antibiotics regimen for osteomyelitis discovered during the operation. Approximately, 2 months after discharge, the patient unfortunately returned with altered mental status, was found to have sepsis, and expired shortly thereafter. This operative video illustrates the technical steps and capabilities of surgical treatment, achieving near-complete gross total resection of a complex SCC lesion using a multidisciplinary approach.

The link to the video can be found at: https://youtu.be/8ffckKIuBzM.

Neurotrauma From Border Wall Jumping: 6 Years at the Mexican-American Border Wall

BACKGROUND

The border between the United States (US) and Mexico is an international boundary spanning 3000 km, where unauthorized crossings occur regularly. We examine patterns of neurotrauma, health care utilization, and financial costs at our level 1 trauma center incurred by patients from wall-jumping into the US.

OBJECTIVE

To determine the clinical and socioeconomic consequences from neurotrauma as a result of jumping over the US-Mexico border wall.

METHODS

Medical records of patients at (Banner University of Arizona Medical Center - Tucson) were retrospectively reviewed from January 2012 through December 2017. Demographics, clinical status, radiographic findings, treatment, length of stay, and financial data were analyzed for all patients suffering neurotrauma during that time.

RESULTS

Over 6 yr, 64 patients sustained cranial or spinal injuries directly from jumping or falling onto US soil from the border wall. Fifty (78%) suffered spinal injuries, 15 (23%) experienced cranial injury, and 1 patient had both. Total medical charges were available in 36 patients and summed $3.6 M, of which 22% was reimbursed, an amount significantly lower than expected from more conventional trauma. Neurotrauma steadily declined over the 6-yr observation period, dropping in 2017 to 6% of rates observed in 2012.

CONCLUSION

In the Southern US, neurotrauma from unauthorized border crossings occurs commonly as a result of wall-jumping. These injuries represent a clinical and costly extreme of border-related trauma, and future efforts from both sides of the border wall are needed to decrease the detrimental impacts felt both by immigrants and surrounding health care systems.

Suprasellar pleomorphic xanthoastrocytoma: A case report

Background:

Pleomorphic xanthoastrocytoma (PXA) is a rare form of astrocytic neoplasm most commonly found in children and young adults. This neoplasm, which is classified as a Grade II tumor by the World Health Organization classification of tumors of the central nervous system, carries a relatively favorable outcome. It is usually found supratentorially in cortical regions of the cerebral hemispheres, and as such, presenting symptoms are similar to other supratentorial cortical neoplasms; with seizures being a common initial symptom. Due to the rarity of this type of neoplasm, PXA arising elsewhere in the brain is often not included in the initial differential diagnosis.

Case Description:

This report presents an extremely rare patient with PXA arising in the suprasellar region who presented with progressive peripheral vision loss. Magnetic resonance imaging of the brain demonstrated a heterogeneous suprasellar mass with cystic and enhancing components initially; the most likely differential diagnosis was craniopharyngioma. The patient underwent endoscopic endonasal resection of the tumor. Microscopically, the tumor was consistent with a glial neoplasm with variable morphology. Based on these findings along with further immunohistochemical workup, the patient was diagnosed with a PXA arising in the suprasellar region. At the 1-year follow-up, the patient remained free of recurrence. Although rare PXA originating in other uncommon locations, such as the spinal cord, cerebellum, the ventricular system, and the pineal region have been previously described.

Conclusion:

Although rare, PXA should be included in the differential diagnosis for solid-cystic tumors arising in the suprasellar region in young adults.

A novel proposed grading system for cerebellar arteriovenous malformations

OBJECTIVE

The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions.

METHODS

Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0-2) or poor (mRS score 3-6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0-1 comprised grade 1, 2-3 grade 2, and 4-5 grade 3.

RESULTS

A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively).

CONCLUSIONS

The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.

Intraoperative brain tumor resection with indocyanine green using augmented microscopy

Treatment outcomes for brain cancer have seen dismal improvements over the last two decades as evident in available statistical data. Efforts to address this challenge include development of near-infrared contrast agents for improvements in diagnostic and therapeutic modalities. This creates a need for imaging technologies that can support the intraoperative use of such agents. Here, we report implementation of a recently introduced augmented microscope in combination with indocyanine green (ICG), a near-infrared contrast agent, for surgical image guidance of a glioma resection in a rat model. Luc-C6 cells were implanted in rats in the left-frontal lobe and grown for 22 days. Surgical resection was performed by a neurosurgeon using the augmented microscope with ICG contrast. ICG accumulated in the tumor tissue due to enhanced permeation and retention from the compromised blood-brain barrier. Videos and images were acquired to evaluate image quality and resection margins. The augmented microscope highlighted tumor tissue regions via visualization of ICG fluorescence and was capable of guiding the rat glioma resection.

Hemodynamics Associated With Intracerebral Arteriovenous Malformations: The Effects of Treatment Modalities

The understanding of the physiology of cerebral arteriovenous malformations (AVMs) continues to expand. Knowledge of the hemodynamics of blood flow associated with AVMs is also progressing as imaging and treatment modalities advance. The authors present a comprehensive literature review that reveals the physical hemodynamics of AVMs, and the effect that various treatment modalities have on AVM hemodynamics and the surrounding cortex and vasculature. The authors discuss feeding arteries, flow through the nidus, venous outflow, and the relative effects of radiosurgical monotherapy, endovascular embolization alone, and combined microsurgical treatments. The hemodynamics associated with intracranial AVMs is complex and likely changes over time with changes in the physical morphology and angioarchitecture of the lesions. Hemodynamic change may be even more of a factor as it pertains to the vast array of single and multimodal treatment options available. An understanding of AVM hemodynamics associated with differing treatment modalities can affect treatment strategies and should be considered for optimal clinical outcomes.

Intracranial Hemorrhage in Patients with Durable Mechanical Circulatory Support Devices: Institutional Review and Proposed Treatment Algorithm

BACKGROUND

Spontaneous intracranial hemorrhage (ICH) is frequently managed in neurosurgery. Patients with durable mechanical circulatory support devices, including total artificial heart (TAH) and left ventricular assist device (LVAD), are often encountered in the setting of ICH. Although durable mechanical circulatory support devices have improved survival and quality of life for patients with advanced heart failure, ICH is one of the most feared complications following LVAD and TAH implantation. Owing to anticoagulation and clinically relevant acquired coagulopathies, ICH should be treated promptly by neurosurgeons and cardiac critical care providers. We provide an analysis of ICH in patients with mechanical circulatory support and propose a treatment algorithm.

METHODS

We retrospectively reviewed medical records from 2013-2016 for patients with a durable mechanical circulatory device at Banner-University of Arizona Medical Center Tucson. All patients with suspected ICH underwent computed tomography scan of the brain. Anticoagulation was managed by the cardiothoracic surgeon.

RESULTS

In 58 patients, an LVAD (n = 49), TAH (n = 10), or both (n = 1) were implanted. Both acquired von Willebrand disease and spontaneous ICH were diagnosed in 5 patients (8.6%) who underwent LVAD implantation. Seven neurosurgical procedures were performed in 2 patients. The overall mortality rate was 60%. Two patients had little or no deficits after treatment with modified Rankin Scale score of 1 and 2, respectively.

CONCLUSIONS

We propose a novel treatment algorithm to manage patients with a LVAD or TAH and ICH, implemented in a multidisciplinary manner to best avoid neurologic and cardiovascular complications.

Socioeconomic and regional differences in the treatment of cervical spondylotic myelopathy

BACKGROUND

Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord dysfunction in the world. Surgical treatment is both medically and economically advantageous, and can be achieved through multiple approaches, with or without fusion. We used the Nationwide Inpatient Sample (NIS) database to better elucidate regional and socioeconomic variances in the treatment of CSM.

METHODS

The NIS database was queried for elective admissions with a primary diagnosis of CSM (ICD-9 721.1). This was evaluated for patients who also carried a diagnosis of anterior (ICD-9 81.02) or posterior cervical fusion (ICD-9 81.03), posterior cervical laminectomy (ICD 03.09), or a combination. We then investigated variances including regional trends and disparities according to hospital and insurance types.

RESULTS

During 2002-2012, 50605 patients were electively admitted with a diagnosis of CSM. Anterior fusions were more common in Midwestern states and in nonteaching hospitals. Fusion procedures were used more frequently than other treatments in private hospitals and with private insurance. Median hospital charges were also expectedly higher for fusion procedures and combined surgical approaches. Combined approaches were found to be significantly greater in patients with concurrent diagnoses of ossification of the posterior longitudinal ligament (OPLL) and CSM. Ultimately, there has been an increased utilization of fusion procedures versus nonfusion treatments, over the past decade, for patients with cervical myelopathy.

CONCLUSIONS

Fusion surgery is being increasingly used for the treatment of CSM. Expensive procedures are being performed more frequently in both private hospitals and for those with private insurance, whereas the most economical procedure, posterior cervical laminectomy, was underutilized.

Complex Skull Base Reconstructions in Kadish D Esthesioneuroblastoma: Case Report

Introduction Advanced Kadish stage esthesioneuroblastoma requires more extensive resections and aggressive adjuvant therapy to obtain adequate disease-free control, which can lead to higher complication rates. We describe the case of a patient with Kadish D esthesioneuroblastoma who underwent multiple surgeries for infectious, neurologic, and wound complications, highlighting potential preventative and salvage techniques.

Case Presentation A 61-year-old man who presented with a large left-sided esthesioneuroblastoma, extending into the orbit, frontal lobe, and parapharyngeal nodes. He underwent margin-free endoscopic-assisted craniofacial resection with adjuvant craniofacial and cervical radiotherapy and concomitant chemotherapy. He then returned with breakdown of his skull base reconstruction and subsequent frontal infections and ultimately received 10 surgical procedures with surgeries for infection-related issues including craniectomy and abscess evacuation. He also had surgeries for skull base reconstruction and CSF leak, repaired with vascularized and free autologous grafts and flaps, synthetic tissues, and CSF diversion.

Discussion Extensive, high Kadish stage tumors necessitate radical surgical resection, radiation, and chemotherapy, which can lead to complications. Ultimately, there are several options available to surgeons, and although precautions should be taken whenever possible, risk of wound breakdown, leak, or infection should not preclude radical surgical resection and aggressive adjuvant therapies in the treatment of esthesioneuroblastoma.

Effective Surgical Management of Competitive Venous Outflow Restriction After Radiosurgery for Cerebral AVMs: Report of 2 Cases

BACKGROUND

Intracranial arteriovenous malformations (AVMs) are complex pathologies. For patients who do not present with hemorrhage, treatment strategies are often predicated on reducing the risk of hemorrhage and minimizing morbidity. Outcomes vary according to the efficacy of treatment selected. Radiosurgical treatment of certain AVMs can result in incomplete obliteration and may also have only a minimal effect on the presenting nonhemorrhagic symptoms.

CASE DESCRIPTIONS

We present 2 cases of patients with AVMs who were initially treated with radiosurgery. Both patients' primary clinical symptoms were headaches, which persisted after radiosurgical treatment but abated after subsequent microsurgical resection with or without endovascular embolization.

CONCLUSION

Venous outflow obstruction is likely a sizable contributive factor in occipital AVMs among patients who present with headaches and symptoms of intracranial hypertension. Because these high-flow lesions may be suboptimally responsive to stereotactic radiosurgery, microsurgical resection, with or without adjunctive endovascular embolization, should be considered as an initial and definitive treatment strategy. Optimal outcomes may be achieved in patients with a visual deficit that is anatomically correlated to their AVMs.

The Role of microRNA Markers in the Diagnosis, Treatment, and Outcome Prediction of Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition that affects many people worldwide. Treatment focuses on controlling secondary injury cascade and improving regeneration. It has recently been suggested that both the secondary injury cascade and the regenerative process are heavily regulated by microRNAs (miRNAs). The measurement of specific biomarkers could improve our understanding of the disease processes, and thereby provide clinicians with the opportunity to guide treatment and predict clinical outcomes after SCI. A variety of miRNAs exhibit important roles in processes of inflammation, cell death, and regeneration. These miRNAs can be used as diagnostic tools for predicting outcome after SCI. In addition, miRNAs can be used in the treatment of SCI and its symptoms. Significant laboratory and clinical evidence exist to show that miRNAs could be used as robust diagnostic and therapeutic tools for the treatment of patients with SCI. Further clinical studies are warranted to clarify the importance of each subtype of miRNA in SCI management.

Chordoma dedifferentiation after proton beam therapy: a case report and review of the literature

Background

Chordoma is a rare invasive bone tumor that may occur anywhere along the neuraxis. A total of three primary histological varieties have been identified: conventional, chondroid, and dedifferentiated.

Case presentation

We report a case of an 8-year-old white girl who presented with conventional chordoma, was treated with surgical resection and mixed proton and photon beam therapy, and had a recurrence in the resection cavity 2.5 years later with dedifferentiated morphology. The recurrent tumor did not express brachyury, a recently identified protein specific to tissue of notochordal origin.

Conclusions

The short time period between radiation therapy and dedifferentiation, low dose of photons, and rarity of dedifferentiated skull base chordomas in pediatric patients should alert clinicians to the possibility of chordoma dedifferentiation after proton beam therapy.

An aggressive multidisciplinary approach reduces mortality in rhinocerebral mucormycosis

Background:

Rhinocerebral mucormycosis occurs in immunocompromised hosts with uncontrolled diabetes, solid organ transplants, and hematologic malignancies. Primary disease is in the paranasal sinuses but often progresses intracranially, via direct extension or angioinvasion. Rhinocerebral mucormycosis is rapidly fatal with a mortality rate of 85%, even when maximally treated with surgical debridement, antifungal therapy, and correction of underlying processes.

Methods:

We performed a retrospective chart review of patients with rhinocerebral mucormycosis from 2011 to 2014. These patients were analyzed for symptoms, surgical and medical management, and outcome. We found four patients who were diagnosed with rhinocerebral mucormycosis. All patients underwent rapid aggressive surgical debridement and were started on antifungal therapy on the day of diagnosis. Overall, we observed a mortality rate of 50%.

Results:

An early aggressive multidisciplinary approach with surgical debridement, antifungal therapy, and correction of underlying disease have been shown to improve survivability in rhinocerebral mucormycosis.

Conclusion:

A multidisciplinary approach to rhinocerebral mucormycosis with otolaryngology, neurosurgery, and ophthalmology, infectious disease and medical intensivists can help reduce mortality in an otherwise largely fatal disease. Even despite these measures, outcomes remain poor, and a high index of suspicion must be maintained in at-risk populations, in order to rapidly execute a multifaceted approach.

Atherogenesis and Lymphstasis...Connecting the Dots

“The Role of Lymphstasis in Atherogenesis” appeared in the Annals of Thoracic Surgery in the March 1981 issue which examined the significance of lymphatic involvement in arteriosclerosis. Presently, the underlying premise of the original paper is reviewed with its relationship to recent information regarding reverse cholesterol transport.Since then, an ncreasing number of articles have been published identifying the proteins and peptides that play a critical role in lymphatic clearance of arterial wall cholesterol. This process, its relationship to the 1981 article, and a concept of arteriosclerosis that explains the scientific merit of the beneficial effects of lifestyle is presented.

Integration of indocyanine green videoangiography with operative microscope: augmented reality for interactive assessment of vascular structures and blood flow

BACKGROUND

Preservation of adequate blood flow and exclusion of flow from lesions are key concepts of vascular neurosurgery. Indocyanine green (ICG) fluorescence videoangiography is now widely used for the intraoperative assessment of vessel patency.

OBJECTIVE

Here, we present a proof-of-concept investigation of fluorescence angiography with augmented microscopy enhancement: real-time overlay of fluorescence videoangiography within the white light field of view of conventional operative microscopy.

METHODS

The femoral artery was exposed in 7 anesthetized rats. The dissection microscope was augmented to integrate real-time electronically processed near-infrared filtered images with conventional white light images seen through the standard oculars. This was accomplished by using an integrated organic light-emitting diode display to yield superimposition of white light and processed near-infrared images. ICG solution was injected into the jugular vein, and fluorescent femoral artery flow was observed.

RESULTS

Fluorescence angiography with augmented microscopy enhancement was able to detect ICG fluorescence in a small artery of interest. Fluorescence appeared as a bright-green signal in the ocular overlaid with the anatomic image and limited to the anatomic borders of the femoral artery and its branches. Surrounding anatomic structures were clearly visualized. Observation of ICG within the vessel lumens permitted visualization of the blood flow. Recorded video loops could be reviewed in an offline mode for more detailed assessment of the vasculature.

CONCLUSION

The overlay of fluorescence videoangiography within the field of view of the white light operative microscope allows real-time assessment of the blood flow within vessels during simultaneous surgical manipulation. This technique could improve intraoperative decision making during complex neurovascular procedures.

On resident duty hour restrictions and neurosurgical training: review of the literature

Within neurosurgery, the national mandate of the 2003 duty hour restrictions (DHR) by the Accreditation Council for Graduate Medical Education (ACGME) has been controversial. Ensuring the proper education and psychological well-being of residents while fulfilling the primary purpose of patient care has generated much debate. Most medical disciplines have developed strategies that address service needs while meeting educational goals. Additionally, there are numerous studies from those disciplines; however, they are not specifically relevant to the needs of a neurosurgical residency. The recent implementation of the 2011 DHR specifically aimed at limiting interns to 16-hour duty shifts has proven controversial and challenging across the nation for neurosurgical residencies--again bringing education and service needs into conflict. In this report the current literature on DHR is reviewed, with special attention paid to neurosurgical residencies, discussing resident fatigue, technical training, and patient safety. Where appropriate, other specialty studies have been included. The authors believe that a one-size-fits-all approach to residency training mandated by the ACGME is not appropriate for the training of neurosurgical residents. In the authors' opinion, an arbitrary timeline designed to limit resident fatigue limits patient care and technical training, and has not improved patient safety.

Augmented microscopy: real-time overlay of bright-field and near-infrared fluorescence images

Intraoperative applications of near-infrared (NIR) fluorescent contrast agents can be aided by instrumentation capable of merging the view of surgical field with that of NIR fluorescence. We demonstrate augmented microscopy, an intraoperative imaging technique in which bright-field (real) and electronically processed NIR fluorescence (synthetic) images are merged within the optical path of a stereomicroscope. Under luminance of 100,000 lx, representing typical illumination of the surgical field, the augmented microscope detects 189 nM concentration of indocyanine green and produces a composite of the real and synthetic images within the eyepiece of the microscope at 20 fps. Augmentation described here can be implemented as an add-on module to visualize NIR contrast agents, laser beams, or various types of electronic data within the surgical microscopes commonly used in neurosurgical, cerebrovascular, otolaryngological, and ophthalmic procedures.

Morbidity and mortality of patients with endovascularly treated intracerebral aneurysms: does physician specialty matter?

OBJECT Endovascular treatment of cerebrovascular pathology, particularly aneurysms, is becoming more prevalent. There is a wide variety in clinical background and training of physicians who treat cerebrovascular pathology through endovascular means. The impact of clinical training background on patient outcomes is not well documented. METHODS The authors conducted a retrospective analysis of a large national database, the University HealthSystem Consortium, that was queried in the years 2009-2013. Cases of both unruptured cerebral aneurysms and subarachnoid hemorrhage treated by endovascular obliteration were studied. Outcome measures of morbidity and mortality were evaluated according to the specialty of the treating physician. RESULTS Elective embolization of an unruptured aneurysm was the procedure code and primary diagnosis, respectively, for 12,400 cases. Patients with at least 1 complication were reported in 799 cases (6.4%). Deaths were reported in 193 cases (1.6%). Complications and deaths were varied by specialty; the highest incidence of complications (11.1%) and deaths (3.0%) were reported by neurologists. The fewest complications were reported by neurosurgeons (5.4%; 1.4% deaths), with a higher incidence of complications reported in cases performed by neurologists (p < 0.0001 for both complications and deaths) and to a lesser degree interventional radiologists (p = 0.0093 for complications). Subarachnoid hemorrhage was the primary diagnosis and procedure for 8197 cases. At least 1 complication was reported in 2385 cases (29%) and deaths in 983 cases (12%). The number of complications and deaths varied among specialties. The highest incidence of complications (34%) and deaths (13.5%) in subarachnoid hemorrhage was in cases performed by neurologists. The fewest complications were in cases by neurosurgeons (27%), with a higher incidence of complications in cases performed by neurologists (34%, p < 0.0001), and a trend of increased complications with interventional radiologists (30%, p < 0.0676). The lowest incidence of mortality was in cases performed by neurosurgeons (11.5%), with a significantly higher incidence of mortality in cases performed by neurologists (13.5%, p = 0.0372). Mortality rates did not reach statistical significance with respect to interventional radiologists (12.1%, p = 0.4884). CONCLUSIONS Physicians of varied training types and backgrounds use endovascular treatment of ruptured and unruptured intracerebral aneurysms. In this study there was a statistically significant finding that neurosurgically trained physicians may demonstrate improved outcomes with respect to endovascular treatment of unruptured aneurysms in this cohort. This finding warrants further investigation.

Microsurgical anatomy of the arterial basket of the conus medullaris

OBJECT The arterial basket of the conus medullaris (ABCM) consists of 1 or 2 arteries arising from the anterior spinal artery (ASA) and circumferentially connecting the ASA and the posterior spinal arteries (PSAs). The arterial basket can be involved in arteriovenous fistulas and arteriovenous malformations of the conus. In this article, the authors describe the microsurgical anatomy of the ABCM with emphasis on its morphometric parameters and important role in the intrinsic blood supply of the conus medullaris. METHODS The authors performed microsurgical dissections on 16 formalin-fixed human spinal cords harvested within 24 hours of death. The course, diameter, and branching angles of the arteries comprising the ABCM were then identified and measured. In addition, histological sections were obtained to identify perforating vessels arising from the ABCM. RESULTS The ASA tapers as it nears the conus medullaris (mean preconus diameter 0.7 ± 0.12 mm vs mean conus diameter 0.38 ± 0.08 mm). The ASA forms an anastomotic basket with the posterior spinal artery (PSA) via anastomotic branches. In most of the specimens (n= 13, 81.3%), bilateral arteries formed connections between the ASA and PSA. However, in the remaining specimens (n= 3, 18.7%), a unilateral right-sided anastomotic artery was identified. The mean diameter of the right ABCM branch was 0.49 ± 0.13 mm, and the mean diameter of the left branch was 0.53 ± 0.14 mm. The mean branching angles of the arteries forming the anastomotic basket were 95.9° ± 36.6° and 90° ± 34.3° for the right- and left-sided arteries, respectively. In cases of bilateral arterial anastomoses between the ASA and PSA, the mean distance between the origins of the arteries was 4.5 ± 3.3 mm. Histological analysis revealed numerous perforating vessels supplying tissue of the conus medullaris. CONCLUSIONS The ABCM is a critical anastomotic connection between the ASA and PSA, which play an important role in the intrinsic blood supply of the conus medullaris. The ABCM provides an important compensatory function in the blood supply of the spinal cord. Its involvement in conus medullaris vascular malformations makes it a critical anatomical structure.

Use of a stop-flow programmable shunt valve to maximize CNS chemotherapy delivery in a pediatric patient with acute lymphoblastic leukemia

BACKGROUND

The requirement for frequent intraventricular drug delivery in the setting of shunt dependence is particularly challenging in the treatment of central nervous system infection, neoplastic disease, and hemorrhage. This is especially relevant in the pediatric population where both hematogenous malignancy requiring intrathecal drug delivery and shunt-dependent hydrocephalus are more prevalent. Intrathecal and intraventricular chemotherapy agents can be prematurely diverted in these shunt-dependent patients.

CASE DESCRIPTION

We report the use of a stop-flow programmable shunt valve to maximize delivery of intraventricular chemotherapy in a child with acute lymphoblastic leukemia and disseminated intravascular coagulation who presented with spontaneous intracerebral and intraventricular hemorrhages. The patient then developed posthemorrhagic hydrocephalus and eventually progressed to shunt dependence but still required frequent intraventricular chemotherapy administration. A ventriculoperitoneal shunt, equipped with a valve that allows for near cessation of cerebrospinal fluid flow (Certas(®), Codman, Raynham, MA), and a contralateral Ommaya reservoir were inserted to maximize intraventricular dissemination of chemotherapy.

CONCLUSIONS

To the best of our knowledge, this is the first reported case of the use of a high-resistance programmable valve being used to virtually cease cerebrospinal fluid flow through the distal catheter temporarily in order to maximize intraventricular drug dissemination in a pediatric patient with acute lymphoblastic leukemia.

Current management and surgical outcomes of medically intractable epilepsy

Epilepsy is one of the most common neurologic disorders in the world. While anti-epileptic drugs (AEDs) are the mainstay of treatment in most cases, as many as one-third of patients will have a refractory form of disease indicating the need for a neurosurgical evaluation. Ever since the first half of the twentieth century, surgery has been a major treatment option for epilepsy, but the last 10-15 years in particular has seen several major advances. As shown in relatively recent studies, resection is more effective for medically intractable epilepsy (MIE) than AED treatment alone, which is why most clinicians now endorse a neurosurgical consultation after approximately two failed regimens of AEDs, ultimately leading to decreased healthcare costs and increased quality of life. Temporal lobe epilepsy (TLE) is the most common form of MIE and comprises about 80% of epilepsy surgeries with the majority of patients gaining complete seizure-freedom. As the number of procedures and different approaches continues to grow, temporal lobectomy remains consistently focused on resection of mesial structures such as the amygdala, hippocampus, and parahippocampal gyrus while preserving as much of the neocortex as possible resulting in optimum seizure control with minimal neurological deficits. MIE originating outside the temporal lobe is also effectively treated with resection. Though not as successful as TLE surgery because of their frequent proximity to eloquent brain structures and more diffuse pathology, epileptogenic foci located extratemporally also benefit from resection. Favorable seizure outcome in each of these procedures has heavily relied on pre-operative imaging, especially since the massive surge in MRI technology just over 20 years ago. However, in the absence of visible lesions on MRI, recent improvements in secondary imaging modalities such as fluorodeoxyglucose positron emission computed tomography (FDG-PET) and single-photon emission computed tomography (SPECT) have lead to progressively better long-term seizure outcomes by increasing the neurosurgeon's visualization of supposed non-lesional foci. Additionally, being historically viewed as a drastic surgical intervention for MIE, hemispherectomy has been extensively used quite successfully for diffuse epilepsies often found in pediatric patients. Although total anatomic hemispherectomy is not utilized as commonly today, it has given rise to current disconnective techniques such as hemispherotomy. Therefore, severe forms of hemispheric developmental epilepsy can now be surgically treated while substantially decreasing the amount of potential long-term complications resulting from cavitation of the brain following anatomical hemispherectomy. Despite the rapid pace at which we are gaining further knowledge about epilepsy and its surgical treatment, there remains a sizeable underutilization of such procedures. By reviewing the recent literature on resective treatment of MIE, we provide a recent up-date on epilepsy surgery while focusing on historical perspectives, techniques, prognostic indicators, outcomes, and complications associated with several different types of procedures.

Osteoblastoma of the lateral skull base: work-up, surgical management, and a review of the literature"

Objectives To describe the work-up and surgical management of an osteoblastoma involving the lateral skull base. Typically occurring in the spine or long bones, osteoblastomas of the craniofacial skeleton are exceedingly rare and infrequently reported. A review of the current literature regarding temporal bone osteoblastoma, diagnosis, and treatment is described. Methods This case report describes the clinical presentation, radiographic studies, surgical management, histology, and postoperative follow-up of a young man presenting to a tertiary care neurotology practice with osteoblastoma involving the lateral skull base. A review of the current literature regarding osteoblastoma of the skull base, work-up, and treatment is described. Results A 15-year-old adolescent boy with a greater than 1-year history of right-sided retroauricular pain, a palpable postauricular mass, and chronic headaches presented for evaluation/management. Microscope examination of the ears, hearing, and cranial nerve function were normal. High-resolution temporal bone computed tomography and magnetic resonance imaging scans were obtained, which revealed an expansile mass involving the junction of the temporal and occipital bones. The patient underwent a combined retrosigmoid/retrolabyrinthine resection of this extradural tumor. Histology revealed a benign bone neoplasm consistent with osteoblastoma. Complete surgical resection was achieved, and the patient's symptoms fully resolved. Follow-up imaging studies found no evidence of recurrence. The scientific literature relevant to work-up and management of osteoblastoma is reviewed. Discussion Osteoblastomas of the lateral skull base are rare, histologically benign tumors that can present with radiographic features suggestive of malignancy. An en bloc resection is important for both diagnosis and definitive treatment of these neoplasms. The differential diagnosis on imaging and histology is discussed.

Injury to the Temporal Lobe via Medial Transorbital Entry of a Toothbrush

Objectives Intracranial penetration by foreign bodies entering via the orbit represent an unusual form of traumatic brain injury. Nevertheless, much is at stake with high risk for cranial nerve and neurovascular injury. We present a case where the bristled end of a toothbrush entered the brain as a projectile via the superior orbital fissure and discuss considerations for surgical management.

Setting A 35-year-old woman suffered a periorbital injury after her husband threw an electric toothbrush at a wall and the head of the toothbrush became a missile that projected through her superior orbital fissure and into her right temporal lobe. She complained of headache and incomplete vision loss in the affected eye.

Intervention After obtaining a cerebrovascular angiogram, we proceeded with emergent orbital decompression and anterograde extraction of the foreign body via a modified frontotemporal orbitozygomatic approach with drilling of the skull base allowing for en bloc removal of the toothbrush.

Conclusions The patient recovered well with improvement in her vision and partial third and sixth nerve palsies. This report illustrates a unique mechanism of injury with a novel intracranial foreign body. We review the neurosurgeon's need for prompt management with an approach customized to the structure of the offending object, the damaged elements, and the surrounding cranial nerves and vascular anatomy.

Accuracy of ventriculostomy catheter placement using a head- and hand-tracked high-resolution virtual reality simulator with haptic feedback

Object

The purpose of this study was to evaluate the accuracy of ventriculostomy catheter placement on a head- and hand-tracked high-resolution and high-performance virtual reality and haptic technology workstation.

Methods

Seventy-eight fellows and residents performed simulated ventriculostomy catheter placement on an ImmersiveTouch system. The virtual catheter was placed into a virtual patient's head derived from a computed tomography data set. Participants were allowed one attempt each. The distance from the tip of the catheter to the Monro foramen was measured.

Results

The mean distance (± standard deviation) from the final position of the catheter tip to the Monro foramen was 16.09 mm (± 7.85 mm).

Conclusions

The accuracy of virtual ventriculostomy catheter placement achieved by participants using the simulator is comparable to the accuracy reported in a recent retrospective evaluation of free-hand ventriculostomy placements in which the mean distance from the catheter tip to the Monro foramen was 16 mm (± 9.6 mm).

Virtual Reality in Neurosurgical Education

OBJECTIVE

Mastery of the neurosurgical skill set involves many hours of supervised intraoperative training. Convergence of political, economic, and social forces has limited neurosurgical resident operative exposure. There is need to develop realistic neurosurgical simulations that reproduce the operative experience, unrestricted by time and patient safety constraints. Computer-based, virtual reality platforms offer just such a possibility. The combination of virtual reality with dynamic, three-dimensional stereoscopic visualization, and haptic feedback technologies makes realistic procedural simulation possible. Most neurosurgical procedures can be conceptualized and segmented into critical task components, which can be simulated independently or in conjunction with other modules to recreate the experience of a complex neurosurgical procedure.

METHODS

We use the ImmersiveTouch (ImmersiveTouch, Inc., Chicago, IL) virtual reality platform, developed at the University of Illinois at Chicago, to simulate the task of ventriculostomy catheter placement as a proof-of-concept. Computed tomographic data are used to create a virtual anatomic volume.

RESULTS

Haptic feedback offers simulated resistance and relaxation with passage of a virtual three-dimensional ventriculostomy catheter through the brain parenchyma into the ventricle. A dynamic three-dimensional graphical interface renders changing visual perspective as the user's head moves. The simulation platform was found to have realistic visual, tactile, and handling characteristics, as assessed by neurosurgical faculty, residents, and medical students.

CONCLUSION

We have developed a realistic, haptics-based virtual reality simulator for neurosurgical education. Our first module recreates a critical component of the ventriculostomy placement task. This approach to task simulation can be assembled in a modular manner to reproduce entire neurosurgical procedures.

Second generation haptic ventriculostomy simulator using the ImmersiveTouch system

Ventriculostomy is a neurosurgical procedure that consists of the insertion of a catheter into the ventricles of the brain for relieving the intracranial pressure. A distinct "popping" sensation is felt as the catheter enters the ventricles. Early ventriculostomy simulators provided some basic audio/visual feedback to simulate the procedure, displaying a 3D virtual model of a human head. Without any tactile feedback, the usefulness of such simulators was very limited. The first generation haptic ventriculostomy simulators incorporated a haptic device to generate a virtual resistance and "give" upon ventricular entry. While this created considerable excitement as a novelty device for cannulating ventricles, its usefulness for teaching and measuring neurosurgical expertise was still very limited. Poor collocation between the haptic device stylus held by the surgeon and the visual representation of the virtual catheter, as well as the lack of a correct viewer-centered perspective, created enormous confusion for the neurosurgeons who diverted their attention from the actual ventriculostomy procedure to overcoming the limitations of the simulator. We present a second generation haptic ventriculostomy simulator succeeding over the major first generation limitations by introducing a head and hand tracking system as well as a high-resolution high-visual-acuity stereoscopic display to enhance the perception and realism of the virtual ventriculostomy.

Thoracoscopic Placement of Dual-Rod Instrumentation in Thoracic Spinal Trauma

OBJECTIVE AND IMPORTANCE

Traditionally, thoracic fractures that require anterior stabilization are treated through an open thoracotomy approach. Thoracoscopic instrumentation avoids many of the complications associated with an open thoracotomy but is technically challenging. We report the first cases of dual-rod internal fixation systems placed thoracoscopically for thoracic spinal trauma.

CLINICAL PRESENTATION

Two male patients sustained midthoracic spinal trauma falling from motorcycles in separate incidents. Both injuries led to unstable spinal columns, but the patients had no neurological deficits and had minimal spinal cord compression. One patient had a complex spiral fracture from T6 to T8; the other had T7 burst and T8 compression fractures. Based on the complex morphological features of the patients' fractures, anterior internal fixation was the treatment of choice for both. The two available options for an anterior stabilization were open thoracotomy and thoracoscopic instrumentation. Because extensive decompression was unnecessary, a thoracoscopic approach was used.

INTERVENTION

A dual-rod internal fixation system (Medtronic Sofamor Danek, Inc., Memphis, TN) was placed with two screws each in the T6 and T9 vertebral bodies of each patient. Thoracoscopy was used for direct visualization of the operative site with fluoroscopic guidance for screw placement. Surgery was completed without complications, and both patients did well afterward. Upright and supine x-rays demonstrated that the constructs were stable at 10 weeks and 6 months, respectively.

CONCLUSION

Thoracoscopic instrumentation offers the advantages of a minimally invasive approach but is technically challenging. The characteristics of dual-rod fixation systems (small-profile components and step-wise insertion) provide the best biomechanical profile and facilitate thoracoscopic instrumentation.

Modifications to the orbitozygomatic approach. Technical note

The orbitozygomatic craniotomy is one of the workhorse approaches of skull base surgery, providing wide, multidirectional access to the anterior and middle cranial fossae as well as the basilar apex. Complete removal of the orbitozygomatic bar increases the angles of exposure, decreases the working depth of the surgical field, and minimizes brain retraction. In many cases, however, only a portion of the exposure provided by the full orbitozygomatic approach is needed. Tailoring the extent of the bone resection to the specific lesion being treated can help lower approach-related morbidity while maintaining its advantages. The authors describe the technical details of the supraorbital and subtemporal modified orbitozygomatic approaches and discuss the surgical indications for their use. Modifications to the orbitozygomatic approach are an example of the ongoing adaptation of skull base procedures to general neurosurgical practice.

Scalp arteriovenous malformation draining into the superior sagittal sinus associated with an intracranial arteriovenous malformation: just a coincidence? Case report

OBJECTIVE AND IMPORTANCE

Recent experimental and clinical evidence suggests that hemodynamic changes in the venous system can induce the formation of new arteriovenous malformations (AVMs). In a rat model, increased venous pressure induces the formation of soft tissue and dural AVMs. We report a clinical observation that may support these data.

CLINICAL PRESENTATION

A 4-year-old boy with a midline scalp AVM draining into the superior sagittal sinus had an associated intracranial/parenchymal AVM. The cerebral AVM increased venous pressure in the superior sagittal sinus as revealed by angiography.

INTERVENTION

The scalp AVM was resected, and the intracranial AVM was treated by use of the gamma knife.

CONCLUSION

On the basis of reported experimental data and the morphological and hemodynamic characteristics in this patient's two lesions, we suggest that the scalp AVM might have been induced by hypertension in the superior sagittal sinus. This clinical observation supports the notion suggested by experimental studies that hemodynamic changes can induce the formation of associated AVMs.

Anterior communicating artery aneurysms

ANTERIOR COMMUNICATING ARTERY aneurysms are complex lesions for which surgical success requires extensive preoperative and intraoperative planning. Adherence to the tenets of aneurysm surgery, including vascular control and preservation of perforating arteries, is essential for their exclusion from the circulation.

Cerebral revascularization performed using posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass. Report of four cases and literature review

Cerebral revascularization is often required for the surgical treatment of complex intracranial aneurysms. In certain anatomical locations, vascular anatomy and redundancy make in situ bypass possible. The authors present four patients who underwent revascularization performed using the rarely reported posterior inferior cerebellar artery (PICA)-PICA in situ bypass after their aneurysms had been trapped. At Barrow Neurological Institute, between 1991 and the present, four male patients underwent PICA-PICA by-passes to treat aneurysms involving the vertebral artery, the PICA, or both. The mean age of these patients was 34 years (range 5-49 years). Follow-up studies revealed patent bypasses and no evidence of infarction. Patient outcomes were excellent or good. Multiple surgical techniques have been described for revascularization of at-risk cerebral territories. Often, the blood supply must be derived from extracranial sources through a mobilized pedicle or interposited graft. Certain anatomical locations such as the vertebrobasilar junction, the anterior circle of Willis, and the middle cerebral artery bifurcation are amenable to in situ bypass because there is vessel redundancy or proximity to the contralateral analogous vessel. The advantages of an in situ bypass include one suture line, a short bypass distance, and a close match with the caliber of the recipient graft. Although technically challenging, this technique can be successful and should be considered for appropriate candidates.

Cerebral revascularization performed using posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass. Report of four cases and literature review

Cerebral revascularization is often required for the surgical treatment of complex intracranial aneurysms. In certain anatomical locations, vascular anatomy and redundancy make in situ bypass possible. The authors present four patients who underwent revascularization performed using the rarely reported posterior inferior cerebellar artery (PICA)-PICA in situ bypass after their aneurysms had been trapped. At Barrow Neurological Institute, between 1991 and the present, four male patients underwent PICA-PICA by-passes to treat aneurysms involving the vertebral artery, the PICA, or both. The mean age of these patients was 34 years (range 5-49 years). Follow-up studies revealed patent bypasses and no evidence of infarction. Patient outcomes were excellent or good. Multiple surgical techniques have been described for revascularization of at-risk cerebral territories. Often, the blood supply must be derived from extracranial sources through a mobilized pedicle or interposited graft. Certain anatomical locations such as the vertebrobasilar junction, the anterior circle of Willis, and the middle cerebral artery bifurcation are amenable to in situ bypass because there is vessel redundancy or proximity to the contralateral analogous vessel. The advantages of an in situ bypass include one suture line, a short bypass distance, and a close match with the caliber of the recipient graft. Although technically challenging, this technique can be successful and should be considered for appropriate candidates.

Interactive stereoscopic virtual reality: a new tool for neurosurgical education. Technical note

The goal of this study was to develop a new method for neurosurgical education based on interactive stereoscopic virtual reality (ISVR). Interactive stereoscopic virtual reality can be used to recreate the three-dimensional (3D) experience of neurosurgical approaches much more realistically than standard educational methods. The demonstration of complex 3D relationships is unrivaled and easily combined with interactive learning and multimedia capabilities. Interactive stereoscopic virtual reality permits the accurate recreation of neurosurgical approaches through integration of several forms of stereoscopic multimedia (video, interactive anatomy, and computer-rendered animations). The content explored using ISVR is obtained through a combination of approach-based cadaver dissections, live surgical images and videos, and computer-rendered animations. These media are combined through an interactive software interface to demonstrate key aspects of a neurosurgical approach (for example, patient positioning, draping, incision, individual surgical steps, alternative steps, relevant anatomy). The ISVR platform is designed for use on a desktop personal computer with newly developed, inexpensive, platform-independent shutter glasses. Interactive stereoscopic virtual reality has been used to capture the anatomy and methods of several neurosurgical approaches. In this paper the authors report their experience with ISVR and describe its potential advantages. The success of a neurosurgical approach is contingent on the mastery of complex, 3D anatomy. A new technology for neurosurgical education, ISVR can improve understanding and speed the learning process. It is an effective tool for neurosurgical education, bridging the substantial gap between textbooks and intraoperative training.