Smart stylet: the development and use of a bedside external ventricular drain image-guidance system.

BACKGROUND: Placement accuracy of ventriculostomy catheters is reported in a wide and variable range. Development of an efficient image-guidance system may improve physician performance and patient safety. OBJECTIVE: We evaluate the prototype of Smart Stylet, a new electromagnetic image-guidance system for use during bedside ventriculostomy. METHODS: Accuracy of the Smart Stylet system was assessed. System operators were evaluated for their ability to successfully target the ipsilateral frontal horn in a phantom model. RESULTS: Target registration error across 15 intracranial targets ranged from 1.3 to 4.6 mm (mean 3.1 mm). Using Smart Stylet guidance, a test operator successfully passed a ventriculostomy catheter to a shifted ipsilateral frontal horn 20/20 (100%) times from the frontal approach in a skull phantom. Without Smart Stylet guidance, the operator was successful 4/10 (40%) times from the right frontal approach and 6/10 (60%) times from the left frontal approach. In a separate experiment, resident operators were successful 2/4 (50%) times when targeting the shifted ipsilateral frontal horn with Smart Stylet guidance and 0/4 (0%) times without image guidance using a skull phantom. CONCLUSIONS: Smart Stylet may improve the ability to successfully target the ventricles during frontal ventriculostomy.

Cerebral capillary telangiectasias: a meta-analysis and review of the literature.

As a result of their presumed benign natural history, cerebral capillary telangiectasias (CCTs) are infrequently addressed in the neurosurgical literature. We performed a comprehensive review of CCTs via the PubMed database to synthesize overall epidemiological, radiographic, natural history, and treatment results. Across ten series with 203 patients, mean age was 47, and 45 % were male [95 % confidence interval (CI), 0.30-0.65]. Notably, 78 % of CCTs were in the pons (95 % CI, 0.58-1.0). Six percent of CCTs were symptomatic. Across five radiographic series, all lesions enhanced after gadolinium, and all were hypointense on gradient echo sequences. Thirty-three percent were hypointense on T1-weighted pre-contrast imaging (95 % CI, 0.2-0.51), 49 % were hyperintense on T2-weighted imaging (95 % CI, 0.31-0.72), and 74 % were hypointense on diffusion-weighted imaging (95 % CI, 0.5-1.0). Notably, 37 % were associated with a prominent draining vein (95 % CI, 0.21-0.6), and 11 % with a developmental venous anomaly (95 % CI, 0.04-0.25). Across four observational studies with 47 patients, there was no observed change in lesion morphology or hemorrhage in 65.7 patient-years of follow-up. Although the vast majority of CCTs are managed conservatively, we found ten cases of patients treated with surgical excision. We confirm that CCTs are a benevolent entity with a predilection for the pons. They have distinctive radiographic features including their lack of mass effect, consistent enhancement on T1-weighted sequences and hypointensity on gradient echo sequences, and common isointensity on pre-contrast T1-weighted and T2-weighted images. Management for these lesions has been nonoperative in almost all cases.

Factors associated with external ventricular drain placement accuracy: data from an electronic health record repository.

BACKGROUND: We evaluated external ventricular drain placement for factors associated with placement accuracy. Data were acquired using an electronic health record data requisition tool. METHOD: Medical records of all patients who underwent ventriculostomy from 2003 to 2010 were identified and evaluated. Patient demographics, diagnosis, type of guidance and number of catheter passes were searched for and recorded. Post-procedural hemorrhage and/or infection were identified. A grading scale was used to classify accuracy of catheter placements. A multiple logistic regression model was developed to assess features associated with accurate catheter placement. RESULTS: One hundred nine patients who underwent 111 ventriculostomies from 2003 to 2010 were identified. Patient diagnoses were classified into vascular (63 %), tumor (21 %), trauma (14 %), and cyst (2 %). Procedures were performed freehand in 90 (81 %), with the Ghajar guide in 17 (15 %), and with image guidance in 4 (4 %) patients. Eighty-eight (79 %) catheters were placed in the correct location. Trauma patients were more likely to have catheters misplaced (p = 0.007) whereas patients in other diagnostic categories were not significantly associated with misplaced catheters. Post-procedural hemorrhage was noted in 2 (1.8 %) patients on post-procedural imaging studies. Five (4.5 %) definite and 6 (5.4 %) suspected infections were identified. CONCLUSIONS: External ventricular drain placement can be performed accurately in most patients. Patients with trauma are more likely to have catheters misplaced. Further development is required to identify and evaluate procedure outcomes using an electronic health record repository.

Stereotactic radiosurgery for cerebral dural arteriovenous fistulas.

OBJECT: Given the feasibility of curative surgical and endovascular therapy for cerebral dural arteriovenous fistulas (DAVFs), there is a relative paucity of radiosurgical series for these lesions as compared with their arteriovenous malformation counterparts. METHODS: The authors reviewed records of 56 patients with 70 cerebral DAVFs treated at their institution over the past 6 years. Ten DAVFs (14%) in 9 patients were treated with stereotactic radiosurgery (SRS), with follow-up obtained for 8 patients with 9 DAVFs. They combined their results with those obtained from a comprehensive review of the literature, focusing on obliteration rates, post-SRS hemorrhage rates, and other complications. RESULTS: In the authors' group of 9 DAVFs, angiographic obliteration was seen in 8 cases (89%), and no post-SRS hemorrhage or complications were observed after a mean follow-up of 2.9 years. Combining the results in these cases with data obtained from their review of the literature, they found 558 DAVFs treated with SRS across 14 series. The overall obliteration rate was 71%; transient worsening occurred in 9.1% of patients, permanent worsening in 2.4% (including 1 death, 0.2% of cases), and post-SRS hemorrhage occurred in 1.6% of cases (4.8% of those with cortical venous drainage [CVD]). The obliteration rate for cavernous DAVFs was 84%, whereas the rates for transversesigmoid and for tentorial DAVFs were 58% and 59%, respectively (adjusted p values, p(cav,TS) = 1.98 × 10(-4), p(cav,tent) = 0.032). Obliteration rates were greater for DAVFs without CVD (80%, compared with 60% for those with CVD, p = 7.59 × 10(-4)). Both transient worsening and permanent worsening were less common in patients without CVD than in those with CVD (3.4% vs 7.3% for transient worsening and 0.9% vs 2.4% for permanent worsening). CONCLUSIONS: Stereotactic radiosurgery with or without adjunctive embolization is an effective therapy for DAVFs that are not amenable to surgical or endovascular monotherapy. It is best suited for lesions without CVD and for cavernous DAVFs.

Patterns in neurosurgical adverse events and proposed strategies for reduction.

Neurosurgery is a high-risk specialty currently undertaking the pursuit of systematic approaches to reducing risk and to measuring and improving outcomes. The authors performed a review of patterns and frequencies of adverse events in neurosurgery as background for future efforts directed at the improvement of quality and safety in neurosurgery. They found 6 categories of contributory factors in neurosurgical adverse events, categorizing the events as influenced by issues in surgical technique, perioperative medical management, use of and adherence to protocols, preoperative optimization, technology, and communication. There was a wide distribution of reported occurrence rates for many of the adverse events, in part due to the absence of definitive literature in this area and to the lack of standardized reporting systems. On the basis of their analysis, the authors identified 5 priority recommendations for improving outcomes for neurosurgical patients at a population level: 1) development and implementation of a national registry for outcome data and monitoring; 2) full integration of the WHO Surgical Safety Checklist into the operating room workflow, which improves fundamental aspects of surgical care such as adherence to antibiotic protocols and communication within surgical teams; and 3-5) activity by neurosurgical societies to drive increased standardization for the safety of specialized equipment used by neurosurgeons (3), more widespread regionalization and/or subspecialization (4), and establishment of data-driven guidelines and protocols (5). The fraction of adverse events that might be avoided if proposed strategies to improve practice and decrease variability are fully adopted remains to be determined. The authors hope that this consolidation of what is currently known and practiced in neurosurgery, the application of relevant advances in other fields, and attention to proposed strategies will serve as a basis for informed and concerted efforts to improve outcomes and patient safety in neurosurgery.

Neurosurgery residency and fellowship education in the United States: 2 decades of system development by the One Neurosurgery Summit organizations.

The purpose of this report is to chronicle a 2-decade period of educational innovation and improvement, as well as governance reform, across the specialty of neurological surgery. Neurological surgery educational and professional governance systems have evolved substantially over the past 2 decades with the goal of improving training outcomes, patient safety, and the quality of US neurosurgical care. Innovations during this period have included the following: creating a consensus national curriculum; standardizing the length and structure of neurosurgical training; introducing educational outcomes milestones and required case minimums; establishing national skills, safety, and professionalism courses; systematically accrediting subspecialty fellowships; expanding professional development for educators; promoting training in research; and coordinating policy and strategy through the cooperation of national stakeholder organizations. A series of education summits held between 2007 and 2009 restructured some aspects of neurosurgical residency training. Since 2010, ongoing meetings of the One Neurosurgery Summit have provided strategic coordination for specialty definition, neurosurgical education, public policy, and governance. The Summit now includes leadership representatives from the Society of Neurological Surgeons, the American Association of Neurological Surgeons, the Congress of Neurological Surgeons, the American Board of Neurological Surgery, the Review Committee for Neurological Surgery of the Accreditation Council for Graduate Medical Education, the American Academy of Neurological Surgery, and the AANS/CNS Joint Washington Committee. Together, these organizations have increased the effectiveness and efficiency of the specialty of neurosurgery in advancing educational best practices, aligning policymaking, and coordinating strategic planning in order to meet the highest standards of professionalism and promote public health.

Intramedullary spinal cord cavernous malformations.

Although originally the subject of rare case reports, intramedullary spinal cord cavernous malformations (CMs) have recently surfaced in an increasing number of case series and natural history reports in the literature. The authors reviewed 27 publications with 352 patients to consolidate modern epidemiological, natural history, and clinical and surgical data to facilitate decision making when managing these challenging vascular malformations. The mean age at presentation was 42 years without a sex predilection. Thirty-eight percent of the cases were cervical, 57% thoracic, 4% lumbar, and 1% unspecified location. Nine percent of the patients had a family history of CNS CMs. Twenty-seven percent of the patients had an associated cranial CM. On presentation 63% of the patients had motor deficits, 65% had sensory deficits, 27% had pain, and 11% had bowel or bladder dysfunction. Presentation was acute in 30%, recurrent in 16%, and progressive in 54% of cases. An overall annual hemorrhage rate was calculated as 2.5% for 92 patients followed up for a total of 2571 patient-years. Across 24 reviewed surgical series, a 91% complete resection rate was found. Transient morbidity was seen in 36% of cases. Sixty-one percent of patients improved, 27% were unchanged, and 12% were worse at the long-term follow-up. Using this information, the authors review surgical nuances in treating these lesions and propose a management algorithm.

Persisting embryonal infundibular recess.

Persisting embryonal infundibular recess (PEIR) is a rare anomaly of the third ventricular floor that has an unclear pathogenesis. In all 7 previously described cases, PEIR was present in adult patients and was invariably associated with hydrocephalus and, in 4 reported cases, with an empty sella. These associated findings led to speculations about the role of increased intraventricular pressure in the development of PEIR. In the present case, PEIR was found in a 24-year-old man without the presence of hydrocephalus or empty sella. Disorders of pituitary function had been present since childhood. Magnetic resonance imaging revealed a cystic expansion in an enlarged sella turcica. A communication between the third ventricle and the sellar cyst was suspected but not apparent. During transcranial surgery, the connection was confirmed. Later, higher-quality MR imaging investigations clearly showed a communication between the third ventricle and the sellar cyst through a channel in the tubular pituitary stalk. This observation and knowledge about the embryology of this region suggests that PEIR may be a developmental anomaly caused by failure of obliteration of the distal part of primary embryonal diencephalic evagination. Thus, PEIR is an extension of the third ventricular cavity into the sella. Although PEIR is a rare anomaly, it is important to identify when planning a procedure on cystic lesions of the sella. Because attempts at removal using the transsphenoidal approach would lead to a communication between the third ventricle and the nasal cavity, a watertight reconstruction of the sellar floor is necessary.

Peri-operative medical management of cerebral vasospasm.

INTRODUCTION: The physiological mechanism of cerebral vasospasm after aneurysmal subarachnoid hemorrhage remains elusive and its treatment can be challenging. Traditionally, 'triple-H' therapy and the calcium channel blocker, nimodipine, are used to treat cerebral vasospasm. However, as the etiology of vasospasm is unraveled, investigative pharmaceutical agents that stop the development and attenuate the severity of cerebral vasospasm, are being investigated in clinical trials. METHODS: In this manuscript, we review the clinical presentation and characteristics of cerebral vasospasm after aneurysmal subarachnoid hemorrhage and the utility of hyperdynamic therapy and pharmacotherapies. RESULTS: Triple-H therapy improves cerebral perfusion and improves neurological outcome during clinically evident cerebral vasospasm. Nimodipine is the accepted standard medication used to reduce the incidence of cerebral vasospasm, but more importantly, has a neuroprotective effect during hypoxia. Other medications such as magnesium sulfate, HMG-CoA reductase inhibitors and enoxaparin, are also being trialed with some promising results. CONCLUSION: Endovascular administration of intra-arterial anti-spasmodic agents and balloon angioplasty are becoming more commonly utilized at institutions where endovascular therapy is available. However, triple-H therapy and nimodipine remain the accepted first-line of treatment for cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

Evidence-based pharmacotherapy for cerebral vasospasm.

INTRODUCTION: The vast amount of literature on the pharmaceutical treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage remains daunting. Optimal treatment regimens for patients can be obscured by studies not statistically powered to draw evidenced-based conclusions. METHODS: In this chapter, we reviewed the English literature using the National Library of Medicine for studies regarding pharmacotherapies for the treatment of cerebral vasospasm. These studies were then categorized according to the US Preventative Services Task Force ranking system for evidence based medicine and reviewed each pharmacotherapy for its efficacy in the treatment of cerebral vasospasm. RESULTS: Nimodipine (Nimotop), HMG Co-A reductase inhibitor (statins) and enoxaparin (Lovenox) were the only drugs with level-1 evidence available for the treatment of vasospasm from aneurysmal subarachnoid hemorrhage as defined by the US Preventative Services Task Force. CONCLUSION: As the understanding of the pathophysiological mechanisms of vasospasm after aneurysmal subarachnoid hemorrhage evolves in the basic science laboratory, novel medications are being trialed in humans. However, significantly more work must be carried out in this area before we have an effective medical treatment that can prevent or reverse the devastating events of cerebral vasospasm.

Retrospective analysis of parenteral magnesium sulfate administration in decreased incidence of clinical and neuroradiological cerebral vasospasm: a single center experience.

OBJECTIVE: Experimental work suggests a neuroprotective role for magnesium sulfate in aneurysmal subarachnoid hemorrhage. We retrospectively review the incidence of clinically relevant vasospasm in patients treated or not with continuous magnesium infusion after onset of subarachnoid hemorrhage. METHODS: All patient records in Albany Medical Center with the diagnosis of SAH between January 1999 and June 2004 were reviewed. Patients who presented to the emergency department within 72 hours of onset were entered in the study. Patients were defined as in clinical vasospasm if there was an acute neurological change in association with abnormal trancranial Doppler (TCD), CT angiogram (CTA) or digital subtraction angiography (DSA). RESULTS: A total of 85 patients were selected. Magnesium sulfate was infused in 43 patients. When compared with patients who did not receive MgSO(4), there was a statistically significant lower incidence of clinical and radiological vasospasm in those who had the continuous infusion of magnesium sulfate (p<0.01). There was no statistically significant difference between patients who were coiled or clipped. CONCLUSION: Continuous magnesium sulfate infusion for the management of clinically significant cerebral vasospasm is safe and reduces the incidence of clinically significant cerebral vasospasm. Large, multicenter, controlled studies should be performed in order to determine the true effectiveness of the treatment in a controlled setting.

Surgical neurology: Harvey Cushing's endangered legacy.

As it does periodically, the United States healthcare system is, yet again, undergoing a period of change on multiple fronts, including internal initiatives in education, quality, and the workforce, as well as external pressure responding to changes in reimbursement and oversight. In such times, looking back at the foundations of our specialty is helpful, allowing often-beleaguered neurosurgeons to reflect upon what it means to be a neurosurgeon, and how they can be assured that our specialty will continue to flourish in the future. Harvey Cushing envisioned, espoused, and developed neurological surgery as a "special field"-a comprehensive, encompassing, and distinct discipline that studies the nervous system and manages neurological disorders. It provides surgical intervention for the treatment of neurological disorders; it by no means was meant to be developed as a mere technical or procedural skill; it is neither a subspecialty of surgery nor a branch of neurology; it is a "special field" that has flourished to become a crown jewel in the realm of medicine. Herein is a perspective that brings the inception and future of this concept to light. A specialty that is to live and flourish should stand on and recognize its roots.

Navigating the Strait of Magellan: mapping a new paradigm for neurosurgical residency training. Presidential address to the Society of Neurological Surgeons, May 7, 2007.

At the conclusion of his year as 81st president of the Society of Neurological Surgeons, the author delivered the following address at the 2007 annual meeting of the Society of Neurological Surgeons in San Francisco. In his address, Dr. Popp used the voyage of Ferdinand Magellan to illustrate the present climate affecting residency training and why the current training paradigm must be examined and, where necessary, changed. Based on this call to action the leaders of the American Association of Neurological Surgeons, The American Board of Neurological Surgeons, The Congress of Neurological Surgeons, The Council of State Neurosurgical Societies, The Residency Review Committee for Neurosurgery, The Society of Neurological Surgeons, and the Washington Committee for Neurosurgery agreed to hold an unprecedented Education Summit meeting to investigate a comprehensive approach to evaluating and changing the current neurosurgical residency training model.

Short-lasting, unilateral neuralgiform headache attacks with conjunctival injection and tearing syndrome treated successfully with transsphenoidal resection of a growth hormone-secreting pituitary adenoma.

Short-lasting, unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome was first described in 1978 as one of the trigeminal autonomic cephalgias. In this paper the authors present a patient with a growth hormone-secreting pituitary adenoma who experienced resolution of SUNCT syndrome after transsphenoidal tumor resection.

Coronary angiojet catheterization for the management of dural venous sinus thrombosis. Technical note.

In most cases of deep venous sinus thrombosis, systemic anticoagulation represents the initial treatment of choice for preventing propagation of a clot in the dural sinuses. In patients with deep or extensive venous sinus thrombosis, a combination of treatment modalities may be required including systemic anticoagulation, selective venous thrombolysis, and mechanical thrombectomy. In the current study the authors report on a patient who presented with the acute onset of headache, vomiting, a depressed level of consciousness, and a left hemiparesis and in whom a right middle cerebral artery (MCA) territory ischemic stroke with hemorrhagic conversion was initially diagnosed. Results of diagnostic cerebral angiography demonstrated a patent right MCA and a deep venous sinus thrombosis involving most of the dural sinuses. Despite adequate systemic heparinization, the patient's neurological condition deteriorated and direct administration of alteplase into the transverse sinus in conjunction with mechanical clot disruption using a coronary AngioJet was required. Venous flow was successfully reestablished in the deep and superficial venous sinuses by using a 0.014-in exchange wire routed from the right common femoral vein through the sinuses and out the left common femoral vein. Excellent angiographic results were obtained, and the patient had recovered completely by the 7-month follow up.

Neurosurgical workforce trends in the United States.

OBJECT: The purpose of this study was to evaluate the US neurosurgery workforce by reviewing journal recruitment advertisements published during the past 10 years. METHODS: The number of available academic and private neurosurgical staff positions was determined based on recruitment advertisements in the Journal of Neurosurgery and Neurosurgery for the 10-year period from 1994 to 2003. Advertisements were evaluated for practice venue, subspecialization, and location. The numbers of active neurosurgeons and graduating residents also were reviewed. The number of advertised neurosurgical positions increased from 141.6 +/- 38.2 per year from 1994 through 1998 to 282.4 +/- 13.6 per year from 1999 through 2003 (mean +/- standard deviation, p < 0.05). The mean number of academic positions increased from 50.6 +/- 11.1 to 95 +/- 17.5 (p < 0.05), and the mean number of private positions rose from 91 +/- 30.4 to 187.4 +/- 6.8 (p < 0.05). Subspecialty positions represented a mean of only 15.6 +/- 5% per year during the first time period and 18.8 +/- 3% per year in the second period (p = 0.22), and therefore the majority of positions advertised continued to be those for generalists. The number of practicing neurosurgeons declined after 1998, and by 2002 it was less than it had been in 1991. The numbers of incoming and matriculating residents during the study period were static. CONCLUSIONS: The number of recruitment advertisements for neurosurgeons during the last 5 years has increased significantly, concomitant with a severe decline in the number of active neurosurgeons and a static supply of residents.

Resident away rotations allow adaptive neurosurgical training.

Subspecialization of physicians and regional centers concentrate the volume of certain rare cases into fewer hospitals. Consequently, the primary institution of a neurological surgery training program may not have sufficient case volume to meet the current Residency Review Committee case minimum requirements in some areas. To ensure the competency of graduating residents through a comprehensive neurosurgical education, programs may need for residents to travel to outside institutions for exposure to cases that are either less common or more regionally focused. We sought to evaluate off-site rotations to better understand the changing demographics and needs of resident education. This would also allow prospective monitoring of modifications to the neurosurgery training landscape. We completed a survey of neurosurgery program directors and query of data from the Accreditation Council of Graduate Medical Education to characterize the current use of away rotations in neurosurgical education of residents. We found that 20% of programs have mandatory away rotations, most commonly for exposure to pediatric, functional, peripheral nerve, or trauma cases. Most of these rotations are done during postgraduate year 3 to 6, lasting 1 to 15 months. Twenty-six programs have 2 to 3 participating sites and 41 have 4 to 6 sites distinct from the host program. Programs frequently offset potential financial harm to residents rotating at a distant site by support of housing and transportation costs. As medical systems experience fluctuating treatment paradigms and demographics, over time, more residency programs may adapt to meet the Accreditation Council of Graduate Medical Education case minimum requirements through the implementation of away rotations.

Revisiting the appropriateness of carotid endarterectomy.

BACKGROUND AND PURPOSE: In the 1980s, carotid endarterectomy was controversial because proof of efficacy was lacking, complication rates were high, and one third of cases were reported to be inappropriate. Since publication of several randomized controlled trials (RCTs), rates of carotid endarterectomy have doubled nationwide. This study assesses the appropriateness and use of carotid endarterectomy since publication of the RCTs. METHODS: Using the literature, we developed a list of 1557 mutually exclusive indications for carotid endarterectomy and asked a panel of national experts to rate the appropriateness of each indication using the RAND methodology. We used these ratings to assess appropriateness in a sample of 2124 patients who underwent the procedure in 1997 to 1998 in 6 hospitals. We also analyzed the reasons for the procedure and rates of death, stroke, and myocardial infarction within 30 days of surgery. RESULTS: Overall, 84.9% of operations were done for appropriate reasons, 4.5% for uncertain reasons, and 10.6% for inappropriate reasons. Among procedures considered inappropriate, the most common reasons were high comorbidity (46.6%) and minimal stenosis (27.1%). Overall, 72.5% were asymptomatic, 17.4% had a carotid transient ischemic attack, and 10.1% had a stroke. The 30-day rate of death or stroke was 5.47% for symptomatic patients and 2.26% for asymptomatic patients. Among patients having combined carotid and coronary artery bypass graft surgery, the rate was 10.32%. The complication rate in asymptomatic patients with high comorbidity was 5.56%. CONCLUSIONS: Since the RCTs, rates of overuse appear to have fallen considerably, although they are still significant. A major shift has occurred toward operating on asymptomatic patients. Although overall complication rates were low, rates among asymptomatic patients with high comorbidity exceeded recommended thresholds.

Gorham disease of the orbit.

PURPOSE: To report a case of Gorham disease, also known as vanishing bone disease, of the orbit. DESIGN: Interventional case report. METHODS: A 43-year-old Caucasian woman developed a depression in her left temple, pulsation in her left upper eyelid and temple, and bulging of the left upper eyelid and headache. Computerized tomography revealed a lytic lesion in the roof of the left orbit. RESULTS: Intraoperative examination of the lesion revealed a bony defect in the left orbital roof. Surgical intervention resulted in improvement of her symptoms, and pathology failed to reveal evidence of malignancy or other benign neoplastic process. CONCLUSION: Gorham disease should be considered in the differential diagnosis of lytic bony lesions of the orbit.