Applying objective metrics to neurosurgical skill development with simulation and spaced repetition learning.

OBJECTIVE: Surgical skills laboratories augment educational training by deepening one's understanding of anatomy and allowing the safe practice of technical skills. Novel, high-fidelity, cadaver-free simulators provide an opportunity to increase access to skills laboratory training. The neurosurgical field has historically evaluated skill by subjective assessment or outcome measures, as opposed to process measures with objective, quantitative indicators of technical skill and progression. The authors conducted a pilot training module with spaced repetition learning concepts to evaluate its feasibility and impact on proficiency. METHODS: The 6-week module used a simulator of a pterional approach representing skull, dura mater, cranial nerves, and arteries (UpSurgeOn S.r.l.). Neurosurgery residents at an academic tertiary hospital completed a video-recorded baseline examination, performing supraorbital and pterional craniotomies, dural opening, suturing, and anatomical identification under a microscope. Participation in the full 6-week module was voluntary, which precluded randomizing by class year. The intervention group participated in four additional faculty-guided trainings. In the 6th week, all residents (intervention and control) repeated the initial examination with video recording. Videos were evaluated by three neurosurgical attendings who were not affiliated with the institution and who were blinded to participant grouping and year. Scores were assigned via Global Rating Scales (GRSs) and Task-based Specific Checklists (TSCs) previously built for craniotomy (cGRS, cTSC) and microsurgical exploration (mGRS, mTSC). RESULTS: Fifteen residents participated (8 intervention, 7 control). The intervention group included a greater number of junior residents (postgraduate years 1-3; 7/8) compared to the control group (1/7). External evaluators had internal consistency within 0.5% (kappa probability > Z of 0.00001). The total average time improved by 5:42 minutes (p < 0.003; intervention, 6:05, p = 0.07; control, 5:15, p = 0.001). The intervention group began with lower scores in all categories and surpassed the comparison group in cGRS (10.93 to 13.6/16) and cTSC (4.0 to 7.4/10). Percent improvements for the intervention group were cGRS 25% (p = 0.02), cTSC 84% (p = 0.002), mGRS 18% (p = 0.003), and mTSC 52% (p = 0.037). For controls, improvements were cGRS 4% (p = 0.19), cTSC 0.0% (p > 0.99), mGRS 6% (p = 0.07), and mTSC 31% (p = 0.029). CONCLUSIONS: Participants who underwent a 6-week simulation course showed significant objective improvement in technical indicators, particularly individuals who were early in their training. Small, nonrandomized grouping limits generalizability regarding degree of impact; however, introducing objective performance metrics during spaced repetition simulation would undoubtedly improve training. A larger multiinstitutional randomized controlled study will help elucidate the value of this educational method.

Multidisciplinary approaches to complication reduction in complex spine surgery: a systematic review.

BACKGROUND CONTEXT: Complex spine surgery carries a high complication rate that can produce suboptimal outcomes for patients undergoing these extensive operations. However, multidisciplinary pathways introduced at multiple institutions have demonstrated a promising potential toward reducing the burden of complications in patients being treated for spinal deformities. To date, there has been no effort to systematically collate the multidisciplinary approaches in use at various institutions. PURPOSE: The present study aims to determine effective multidisciplinary strategies for reducing the complication rate in complex spine surgery by analyzing existing institutional multidisciplinary approaches and delineating common themes across multiple practice settings. STUDY DESIGN: Systematic review. METHODS: We followed guidelines established under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The studies reported on data from PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Cochrane. We included articles that described either approaches to, or results from, the implementation of multidisciplinary paradigms during the preoperative, perioperative, and postoperative phases of care for patients undergoing complex spine surgery. We excluded studies that only targeted one complication unless such an approach was in coordination with more extensive multidisciplinary planning at the same institution. RESULTS: A total of 406 unique articles were identified. Following an initial determination based on title and abstract, 22 articles met criteria for full-text review, and 10 met the inclusion criteria to be included in the review. Key aspects of multidisciplinary approaches to complex spine surgery included extensive preoperative workup and interdisciplinary conferencing, intraoperative communication and monitoring, and postoperative floor management and discharge planning. These strategies produced decreases in surgical duration and complication rates. CONCLUSIONS: This study represents the first to systematically analyze multidisciplinary approaches to reduce complications in complex spine surgery. This review provides a roadmap toward reducing the elevated complication rate for patients undergoing complex spine surgery.

Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis.

BACKGROUND: The comparative effectiveness of performing instrumented (rigid pedicle screws affixed to titanium alloy rods) lumbar spinal fusion in addition to decompressive laminectomy in patients with symptomatic lumbar grade I degenerative spondylolisthesis with spinal stenosis is unknown. METHODS: In this randomized, controlled trial, we assigned patients, 50 to 80 years of age, who had stable degenerative spondylolisthesis (degree of spondylolisthesis, 3 to 14 mm) and symptomatic lumbar spinal stenosis to undergo either decompressive laminectomy alone (decompression-alone group) or laminectomy with posterolateral instrumented fusion (fusion group). The primary outcome measure was the change in the physical-component summary score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36; range, 0 to 100, with higher scores indicating better quality of life) 2 years after surgery. The secondary outcome measure was the score on the Oswestry Disability Index (range, 0 to 100, with higher scores indicating more disability related to back pain). Patients were followed for 4 years. RESULTS: A total of 66 patients (mean age, 67 years; 80% women) underwent randomization. The rate of follow-up was 89% at 1 year, 86% at 2 years, and 68% at 4 years. The fusion group had a greater increase in SF-36 physical-component summary scores at 2 years after surgery than did the decompression-alone group (15.2 vs. 9.5, for a difference of 5.7; 95% confidence interval, 0.1 to 11.3; P=0.046). The increases in the SF-36 physical-component summary scores in the fusion group remained greater than those in the decompression-alone group at 3 years and at 4 years (P=0.02 for both years). With respect to reductions in disability related to back pain, the changes in the Oswestry Disability Index scores at 2 years after surgery did not differ significantly between the study groups (-17.9 in the decompression-alone group and -26.3 in the fusion group, P=0.06). More blood loss and longer hospital stays occurred in the fusion group than in the decompression-alone group (P<0.001 for both comparisons). The cumulative rate of reoperation was 14% in the fusion group and 34% in the decompression-alone group (P=0.05). CONCLUSIONS: Among patients with degenerative grade I spondylolisthesis, the addition of lumbar spinal fusion to laminectomy was associated with slightly greater but clinically meaningful improvement in overall physical health-related quality of life than laminectomy alone. (Funded by the Jean and David Wallace Foundation and others; SLIP ClinicalTrials.gov number, NCT00109213.).

Giant thoracic osteophyte: a distinct clinical entity.

Calcified lesions described within the neural axis are classified as either an ossification of the posterior longitudinal ligament, diffuse idiopathic skeletal hyperostosis, or ossification of the ligamentum flavum. We aim to describe a unique pathologic entity: the giant thoracic osteophyte. We identified four patients who were surgically treated at the Massachusetts General Hospital from 2006 to 2012 with unusual calcified lesions in the ventral aspect of the spinal canal. In order to differentiate giant thoracic osteophytes from calcified extruded disc material, disc volumetrics were performed on actual and simulated disc spaces. All patients underwent operative resection of the calcific lesion as they had signs and/or symptoms of spinal cord compression. The lesions were found to be isolated, large calcific masses that originated from the posterior aspect of adjacent thoracic vertebral bodies. Pathological examination was negative for tumor. Adjacent disc volumes were not significantly different from the index disc (p=0.91). A simulated calculation hypothesizing that the calcific mass was extruded disc material demonstrated a significant difference (p=0.01), making this scenario unlikely. In conclusion, giant thoracic osteophyte is a unique and rare entity that can be found in the thoracic spine. The central tenant of surgical treatment is resection to relieve spinal cord compression.

Surgical treatment options and management strategies of metastatic renal cell carcinoma to the lumbar spinal nerve roots.

Spinal nerve root metastasis of renal cell carcinoma is a rare occurrence. In addition to treatment of the primary lesion, surgical resection of the nerve root metastasis, occasionally with sacrifice of the involved nerve, is the accepted standard of treatment. Resection often resolves presenting motor and pain symptoms due to relief of neural compression. We describe two patients with nerve root metastasis of renal cell carcinoma and their management. While locally advanced and metastatic renal cell carcinoma has been shown to be chemo- and radio-resistant, immunotherapy is a promising treatment. Given the high prevalence of systemic disease in patients with intradural metastases, systemic (and possibly intracranial) imaging can be used to identify other potential areas of disease.

Induced and sustained hypernatremia for the prevention and treatment of cerebral edema following brain injury.

Cerebral edema develops in response to and as a result of a variety of neurologic insults such as ischemic stroke, traumatic brain injury, and tumor. It deforms brain tissue, resulting in localized mass effect and increase in intracranial pressure (ICP) that are associated with a high rate of morbidity and mortality. When administered in bolus form, hyperosmolar agents such as mannitol and hypertonic saline have been shown to reduce total brain water content and decrease ICP, and are currently the mainstays of pharmacological treatment. However, surprisingly, little is known about the increasingly common clinical practice of inducing a state of sustained hypernatremia. Herein, we review the available studies employing sustained hyperosmolar therapy to induce hypernatremia for the prevention and/or treatment of cerebral edema. Insufficient evidence exists to recommend pharmacologic induction of hypernatremia as a treatment for cerebral edema. The strategy of vigilant avoidance of hyponatremia is currently a safer, potentially more efficacious paradigm.

Neurological surgery: the influence of physical and mental demands on humans performing complex operations.

Performing neurological surgery is an inherently demanding task on the human body, both physically and mentally. Neurosurgeons routinely perform "high stakes" operations in the setting of mental and physical fatigue. These conditions may be not only the result of demanding operations, but also influential to their outcome. Similar to other performance-based endurance activities, training is paramount to successful outcomes. The inflection point, where training reaches the point of diminishing returns, is intensely debated. For the neurosurgeon, this point must be exploited to the maximum, as patients require both the best-trained and best-performing surgeon. In this review, we explore the delicate balance of training and performance, as well as some routinely used adjuncts to improve human performance.

Infection following operations on the central nervous system: deconstructing the myth of the sterile field.

Neurosurgical patients are at a high risk for infectious sequelae following operations. For neurosurgery in particular, the risk of surgical site infection has a unique implication given the proximity of the CSF and the CNS. Patient factors contribute to some degree; for example, cancer and trauma are often associated with impaired nutritional status, known risk factors for infection. Additionally, care-based factors for infection must also be considered, such as the length of surgery, the administration of steroids, and tissue devascularization (such as a craniotomy bone flap). When postoperative infection does occur, attention is commonly focused on potential lapses in surgical "sterility." Evidence suggests that the surgical field is not free of microorganisms. The authors propose a paradigm shift in the nomenclature of the surgical field from "sterile" to "clean." Continued efforts aimed at optimizing immune capacity and host defenses to combat potential infection are warranted.

Socioeconomic status correlates with the prevalence of advanced coronary artery disease in the United States.

BACKGROUND: Increasingly studies have identified socioeconomic factors adversely affecting healthcare outcomes for a multitude of diseases. To date, however, there has not been a study correlating socioeconomic details from nationwide databases on the prevalence of advanced coronary artery disease. We seek to identify whether socioeconomic factors contribute to advanced coronary artery disease prevalence in the United States. METHODS AND FINDINGS: State specific prevalence data was queried form the United States Nationwide Inpatient Sample for 2009. Patients undergoing percutaneous coronary angioplasty and coronary artery bypass graft were identified as principal procedures. Non-cardiac related procedures, lung lobectomy and hip replacement (partial and total) were identified and used as control groups. Information regarding prevalence was then merged with data from the Behavioral Risk Factor Surveillance System, the largest, on-going telephone health survey system tracking health conditions and risk behaviors in the United States. Pearson's correlation coefficient was calculated for individual socioeconomic variables including employment status, level of education, and household income. Household income and education level were inversely correlated with the prevalence of percutaneous coronary angioplasty (-0.717; -0.787) and coronary artery bypass graft surgery (-0.541; -0.618). This phenomenon was not seen in the non-cardiac procedure control groups. In multiple linear regression analysis, socioeconomic factors were significant predictors of coronary artery bypass graft and percutaneous transluminal coronary angioplasty (p<0.001 and p=0.005, respectively). CONCLUSIONS: Socioeconomic status is related to the prevalence of advanced coronary artery disease as measured by the prevalence of percutaneous coronary angioplasty and coronary artery bypass graft surgery.

Delayed post-traumatic bilateral abducens nerve palsy with complete recovery.

Isolated bilateral abducens (sixth) nerve palsy is rare in the setting of trauma. To date, most cases have been reported in patients who sustain cranial fractures or have other acute intracranial pathologies, including acute hemorrhage. We describe the case of a 41-year-old man who presented with bilateral abducens nerve palsy in the setting of acute head trauma without evidence of cranial fractures or other acute intracranial pathology. Six months after the initial injury, he regained bilateral function of his abducens nerves with intact extraocular muscle movements. Full recovery is the natural history in the majority of traumatic abducens nerve palsies, and this is an important consideration when counseling patients with such injuries.

The use of intra-operative blood gas analysis in the investigation of suspected iatrogenic vascular injury.

BACKGROUND: Iatrogenic injury to the vertebral artery during posterior cervical fusion is a rare and potentially disastrous complication. Differentiating arterial from brisk venous bleeding would be ideal to assist in the intra-operative management. Definitive angiography is typically not feasible during most routine spine surgery. CASE DESCRIPTION: We describe the case of a patient undergoing an occipitocervical fusion, where brisk bleeding was encountered during dissection of the CB lateral mass. While the dissection was thought to be superficial to critical structures, the nature of the hemorrhage could not be definitely determined by visual inspection by two senior surgeons. The hemorrhage did not readily cease with standard maneuvers such as, the application of various hemostatic agents. Simultaneous blood gas analysis was performed on samples obtained from the patient's radial artery and from the hemorrhage in the operative bed. Comparative analysis concluded that the bleeding encountered in the surgical field was venous in nature. CONCLUSION: Blood gas analysis can be a useful adjunct in determining the nature of hemorrhage from vascular structures in spine surgery when visual inspection is indeterminate.

Craniectomy for malignant cerebral infarction: prevalence and outcomes in US hospitals.

OBJECT: Randomized trials have demonstrated the efficacy of craniectomy for the treatment of malignant cerebral edema following ischemic stroke. We sought to determine the prevalence and outcomes related to this by using a national database. METHODS: Patient discharges with ischemic stroke as the primary diagnosis undergoing craniectomy were queried from the US Nationwide Inpatient Sample from 1999 to 2008. A subpopulation of patients was identified that underwent thrombolysis. Two primary end points were examined: in-hospital mortality and discharge to home/routine care. To facilitate interpretations, adjusted prevalence was calculated from the overall prevalence and two age-specific logistic regression models. The predictive margin was then generated using a multivariate logistic regression model to estimate the probability of in-hospital mortality after adjustment for admission type, admission source, length of stay, total hospital charges, chronic comorbidities, and medical complications. RESULTS: After excluding 71,996 patients with the diagnosis of intracranial hemorrhage and posterior intracranial circulation occlusion, we identified 4,248,955 adult hospitalizations with ischemic stroke as a primary diagnosis. The estimated rates of hospitalizations in craniectomy per 10,000 hospitalizations with ischemic stroke increased from 3.9 in 1999-2000 to 14.46 in 2007-2008 (p for linear trend<0.001). Patients 60+ years of age had in-hospital mortality of 44% while the 18-59 year old group was found to be 24% (p = 0.14). Outcomes were comparable if recombinant tissue plasminogen activator had been administered. CONCLUSIONS: Craniectomy is being increasingly performed for malignant cerebral edema following large territory cerebral ischemia. We suspect that the increase in the annual incidence of DC for malignant cerebral edema is directly related to the expanding collection of evidence in randomized trials that the operation is efficacious when performed in the correct patient population. In hospital mortality is high for all patients undergoing this procedure.

Incidental vertebral lesions.

Incidental vertebral lesions on imaging of the spine are commonly encountered in clinical practice. Contributing factors include the aging population, the increasing prevalence of back pain, and increased usage of MR imaging. Additionally, refinements in CT and MR imaging have increased the number of demonstrable lesions. The management of incidental findings varies among practitioners and commonly depends more on practice style than on data or guidelines. In this article we review incidental findings within the vertebral column and review management of these lesions, based on available Class III data.

Diagnostic pitfalls in spine surgery: masqueraders of surgical spine disease.

Disorders of the spine are common in clinical medicine, and spine surgery is being performed with increasing frequency in the US. Although many patients with an established diagnosis of a true surgically treatable lesion are referred to a neurosurgeon, the evaluation of patients with spinal disorders can be complex and fraught with diagnostic pitfalls. While "common conditions are common," astute clinical acumen and vigilance are necessary to identify lesions that masquerade as surgically treatable spine disease that can lead to erroneous diagnosis and treatment. In this review, the authors discuss musculoskeletal, peripheral nerve, metabolic, infectious, inflammatory, and vascular conditions that mimic the syndromes produced by surgical lesions. It is possible that nonsurgical and surgical conditions coexist at times, complicating treatment plans and natural histories. Awareness of these diagnoses can help reduce diagnostic error, thereby avoiding the morbidity and expense associated with an unnecessary operation.

Familial Chiari malformation: case series.

Chiari malformations (Types I-IV) are abnormalities of the posterior fossa that affect the cerebellum, brainstem, and the spinal cord with prevalence rates of 0.1%-0.5%. Case reports of familial aggregation of Chiari malformation, twin studies, cosegregation of Chiari malformation with known genetic conditions, and recent gene and genome-wide association studies provide strong evidence of the genetic underpinnings of familial Chiari malformation. The authors report on a series of 3 family pairs with Chiari malformation Type I: 2 mother-daughter pairs and 1 father-daughter pair. The specific genetic causes of familial Chiari malformation have yet to be fully elucidated. The authors review the literature and discuss several candidate genes. Recent advances in the understanding of the genetic influences and pathogenesis of familial Chiari malformation are expected to improve management of affected patients and monitoring of at-risk family members.

Rapidly progressive lumbar subdural empyema following acromial bursal injection.

Spinal subdural empyemas are rare. We describe a 53-year-old male who presented with back pain, mental status changes, and sepsis. Five days prior he had undergone a triamcinolone and lidocaine injection of the acromial bursa. He also had a remote history of epidural steroid injection for thoracic back pain. Two lumbar MRI conducted 62 hours apart revealed a newly developed subdural empyema that was successfully treated with surgical evacuation and post-operative antibiotics.

Trends in inpatient setting laminectomy for excision of herniated intervertebral disc: Population-based estimates from the US nationwide inpatient sample.

BACKGROUND: Herniated intervertebral discs can result in pain and neurological compromise. Treatment for this condition is categorized as surgical or non-surgical. We sought to identify trends in inpatient surgical management of herniated intervertebral discs using a national database. METHODS: Patient discharges identified with a principal procedure relating to laminectomy for excision of herniated intervertebral disc were selected from the Nationwide Inpatient Sample (Healthcare Cost and Utilization Project - Agency for Healthcare Research and Quality, Rockville, MD), under the auspices of a data user agreement. These surgical patients did not undergo instrumented fusion. To account for the Nationwide Inpatient Sample weighting schema, design-adjusted analyses were used. The estimates of standard errors were calculated using SUDAAN software (Research Triangle International, NC, USA). This software is based on the International Classification of Diseases, 9(th) Revision, Clinical Modification (ICD-9-CM); a uniform and standardized coding system. RESULTS: Using International Classification of Disease 9(th) Revision clinical modifier (ICD-9 CM) procedure code 80.51, we were able to identify disc excision, in part or whole, by laminotomy or hemilaminectomy. The incidence of laminectomy for the excision of herniated intervertebral disc has decreased dramatically from 1993 where 266,152 cases were reported [CI = 22,342]. In 2007, only 123,398 cases were identified [CI = 12,438]. The average length of stay in 1993 was 4 days [CI = 0.17], and in 2007 it decreased to just 2 days [CI = 0.17]. Both these comparisons were significantly different at P < 0.001. The average inflation adjusted (2007 buying power) charge of the procedure in 1993 was 14,790.87 USD [CI = 916.85]. This value rose in 2007 to 24,639 USD [CI = 1,485.51]. This difference was significant at P < 0.001. CONCLUSIONS: National estimates indicate that the incidence of inpatient laminectomy for the excision of herniated intervertebral disc has decreased significantly. This trend is multifactorial and is likely related to developments in outcomes research, the growing popularity of alternative procedures (intervertebral instrumented fusion), and transition to an ambulatory setting of surgical care.

Comparative effectiveness of ventral vs dorsal surgery for cervical spondylotic myelopathy.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction. OBJECTIVE: To determine the feasibility of a randomized clinical trial comparing the clinical effectiveness and costs of ventral vs dorsal decompression with fusion surgery for treating CSM. METHODS: A nonrandomized, prospective, clinical pilot trial was conducted. Patients ages 40 to 85 years with degenerative CSM were enrolled at 7 sites over 2 years (2007-2009). Outcome assessments were obtained preoperatively and at 3 months, 6 months, and 1 year postoperatively. A hospital-based economic analysis used costs derived from hospital charges and Medicare cost-to-charge ratios. RESULTS: The pilot study enrolled 50 patients. Twenty-eight were treated with ventral fusion surgery and 22 with dorsal fusion surgery. The average age was 61.6 years. Baseline demographics and health-related quality of life (HR-QOL) scores were comparable between groups; however, dorsal surgery patients had significantly more severe myelopathy (P<.01). Comprehensive 1-year follow-up was obtained in 46 of 50 patients (92%). Greater HR-QOL improvement (Short-Form 36 Physical Component Summary) was observed after ventral surgery (P=.05). The complication rate (16.6% overall) was comparable between groups. Significant improvement in the modified Japanese Orthopedic Association scale score was observed in both groups (P<.01). Dorsal fusion surgery had significantly greater mean hospital costs ($29 465 vs $19 245; P<.01) and longer average length of hospital stay (4.0 vs 2.6 days; P<.01) compared with ventral fusion surgery. CONCLUSION: Surgery for treating CSM was followed by significant improvement in disease-specific symptoms and in HR-QOL. Greater improvement in HR-QOL was observed after ventral surgery. Dorsal fusion surgery was associated with longer length of hospital stay and higher hospital costs. The pilot study demonstrated feasibility for a larger randomized clinical trial.

Cervical radiculopathy: pathophysiology, presentation, and clinical evaluation.

Cervical radiculopathy is a common condition that usually results from compression and inflammation of the cervical nerve root or roots in the region of the neural foramen. It is frequently caused by cervical disc herniation and cervical spondylosis. The diagnosis can be established by history and physical examination, but care should be taken, as diagnoses can mimic or coexist with cervical radiculopathy, such as entrapment neuropathies. The pathophysiology, presentation, and clinical evaluation of cervical radiculopathy are discussed.