Timing of syrinx reduction and stabilization after posterior fossa decompression for pediatric Chiari malformation type I.

OBJECTIVE: The aim of this study was to determine the timeline of syrinx regression and to identify factors mitigating syrinx resolution in pediatric patients with Chiari malformation type I (CM-I) undergoing posterior fossa decompression (PFD). METHODS: The authors conducted a retrospective review of records from pediatric patients (< 18 years old) undergoing PFD for the treatment of CM-I/syringomyelia (SM) between 1998 and 2015. Patient demographic, clinical, radiological, and surgical variables were collected and analyzed. Radiological information was reviewed at 4 time points: 1) pre-PFD, 2) within 6 months post-PFD, 3) within 12 months post-PFD, and 4) at maximum available follow-up. Syrinx regression was defined as ≥ 50% decrease in the maximal anteroposterior syrinx diameter (MSD). The time to syrinx regression was determined using Kaplan-Meier analysis. Multivariate analysis was conducted using a Cox proportional hazards model to determine the association between preoperative, clinical, and surgery-related factors and syrinx regression. RESULTS: The authors identified 85 patients with CM-I/SM who underwent PFD. Within 3 months post-PFD, the mean MSD regressed from 8.1 ± 3.4 mm (preoperatively) to 5.6 ± 2.9 mm within 3 months post-PFD. Seventy patients (82.4%) achieved ≥ 50% regression in MSD. The median time to ≥ 50% regression in MSD was 8 months (95% CI 4.2-11.8 months). Using a risk-adjusted multivariable Cox proportional hazards model, the patients who underwent tonsil coagulation (n = 20) had a higher likelihood of achieving ≥ 50% syrinx regression in a shorter time (HR 2.86, 95% CI 1.2-6.9; p = 0.02). Thirty-six (75%) of 45 patients had improvement in headache at 2.9 months (IQR 1.5-4.4 months). CONCLUSIONS: The maximum reduction in syrinx size can be expected within 3 months after PFD for patients with CM-I and a syrinx; however, the syringes continue to regress over time. Tonsil coagulation was associated with early syrinx regression in this cohort. However, the role of surgical maneuvers such as tonsil coagulation and arachnoid veil identification and sectioning in the overall role of CM-I surgery remains unclear.

Measuring degeneration of the lateral geniculate nuclei from pituitary adenoma compression detected by 7T ultra-high field MRI: a method for predicting vision recovery following surgical decompression of the optic chiasm.

OBJECTIVE: Predicting vision recovery following surgical decompression of the optic chiasm in pituitary adenoma patients remains a clinical challenge, as there is significant variability in postoperative visual function that remains unreliably explained by current prognostic factors. Available literature inadequately characterizes alterations in adenoma patients involving the lateral geniculate nucleus (LGN). This study examined the association of LGN degeneration with chiasmatic compression as well as with the retinal nerve fiber layer (RNFL), pattern standard deviation (PSD), mean deviation (MD), and postoperative vision recovery. PSD is the degree of difference between the measured visual field pattern and the normal pattern ("hill") of vision, and MD is the average of the difference from the age-adjusted normal value. METHODS: A prospective study of 27 pituitary adenoma patients and 27 matched healthy controls was conducted. Participants were scanned on a 7T ultra-high field MRI scanner, and 3 independent readers measured the LGN at its maximum cross-sectional area on coronal T1-weighted MPRAGE imaging. Readers were blinded to diagnosis and to each other's measurements. Neuro-ophthalmological data, including RNFL thickness, MD, and PSD, were acquired for 12 patients, and postoperative visual function data were collected on patients who underwent surgical chiasmal decompression. LGN areas were compared using two-tailed t-tests. RESULTS: The average LGN cross-sectional area of adenoma patients was significantly smaller than that of controls (13.8 vs 19.2 mm2, p < 0.0001). The average LGN cross-sectional area correlated with MD (r = 0.67, p = 0.04), PSD (r = -0.62, p = 0.02), and RNFL thickness (r = 0.75, p = 0.02). The LGN cross-sectional area in adenoma patients with chiasm compression was 26.6% smaller than in patients without compression (p = 0.009). The average tumor volume was 7902.7 mm3. Patients with preoperative vision impairment showed 29.4% smaller LGN cross-sectional areas than patients without deficits (p = 0.003). Patients who experienced improved postoperative vision had LGN cross-sectional areas that were 40.8% larger than those of patients without postoperative improvement (p = 0.007). CONCLUSIONS: The authors demonstrate novel in vivo evidence of LGN volume loss in pituitary adenoma patients and correlate imaging results with neuro-ophthalmology findings and postoperative vision recovery. Morphometric changes to the LGN may reflect anterograde transsynaptic degeneration. These findings indicate that LGN degeneration may be a marker of optic apparatus injury from chiasm compression, and measurement of LGN volume loss may be useful in predicting vision recovery following adenoma resection.

Perioperative Risk Factors for Thirty-Day Morbidity and Mortality in the Resection of Extradural Thoracic Spine Tumors.

OBJECTIVE: Resection of epidural thoracic spine tumors is uniquely challenging owing to the dangers posed by the surrounding anatomy and the unforgiving nature of the thoracic spinal cord. We assessed the preoperative and postoperative risk factors for 30-day morbidity and mortality in patients undergoing resection of these tumors. METHODS: Adults who underwent laminectomy for excision of thoracic spine tumors from 2011 to 2014 were included. The demographic data and medical comorbidities and major morbidities and mortalities within 30 postoperative days were collected and assessed using multivariate binary logistic analysis. RESULTS: The database search yielded 616 patients, of whom 232 (37.7%) were female. Overall, complications within 30 days of surgery occurred in 322 patients (52.3%). Of the 616 patients, 64 (10.4%) died within 30 days of surgery. Smoking history was associated with significantly greater 30-day morbidity (P = 0.019), as was preoperative anemia for females (P = 0.003) and preoperative hypoalbuminemia (P < 0.0001), with the need for preoperative blood transfusion also leading to greater morbidity (P = 0.001). The presence of preoperative dyspnea and congestive heart failure increased the risk of complications (P = 0.001). Preoperative hypoalbuminemia (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.8-7.0), dependent functional status (OR, 3.6; 95% CI, 1.7-7.6), and bleeding disorder (OR, 7.1; 95% CI, 2.5-20.1) were significantly associated with 30-day mortality. Deep vein thrombosis/pulmonary embolism, nonthrombotic pulmonary complications, and blood transfusions were common post- and perioperative complications. CONCLUSIONS: Excision of epidural thoracic spinal tumors carries a high complication rate. The present series has revealed distinct preoperative and postoperative factors that contribute to 30-day morbidity and mortality for tumors in this region, many of which are amenable to careful preoperative management.

Risk Factors for Thirty-Day Morbidity and Mortality in Extradural Lumbar Spine Tumor Resection.

BACKGROUND: Epidural tumors in the lumbar spine represent a unique cohort of lesions with individual risks and challenges to resection. Knowledge of modifiable risk factors are important in minimizing postoperative complications. OBJECTIVE: To determine the risk factors for 30-day morbidity and mortality in patients undergoing extradural lumbar tumor resection. METHODS: A retrospective study of prospectively collected data using the American College of Surgeons National Quality Improvement Program database was performed. Adults who underwent laminectomy for excision of lumbar spine tumors between 2011 and 2014 were included in the study. Demographics and medical comorbidities were collected, along with morbidities and mortalities within 30 postoperative days. A multivariate binary logistic analysis of these clinical variables was performed to determine covariates of morbidity and mortality. RESULTS: The database search yielded 300 patients, of whom 118 (39.3%) were female. Overall, complications within 30 days of surgery occurred in 102 (34%) patients. Significant risk factors for morbidity included preoperative anemia (P < 0.0001), the need for preoperative blood transfusion (P = 0.034), preoperative hypoalbuminemia (P = 0.002), American Society of Anesthesiologists score 3 or 4 (P = 0.0002), and operative time >4 hours (P < 0.0001). Thirty-day mortality occurred in 15 (5%) patients and was independently associated with preoperative anemia (odds ratio 3.4, 95% confidence interval 1.8-6.5) and operative time >4 hours (odds ratio 2.6, 95% confidence interval 1.1-6.0). CONCLUSIONS: Excision of epidural lumbar spinal tumors carries a relatively high complication rate. This series reveals distinct risk factors that contribute to 30-day morbidity and mortality, which may be optimized preoperatively to improve surgical safety.

Morbidity and Mortality of Meningioma Resection Increases in Octogenarians.

BACKGROUND: The incidence of meningioma has increased drastically recently, particularly in older adults. Surgical intervention has the potential to reduce neurologic symptoms and achieve favorable, long-term outcomes. There is considerable variability in the literature examining the relationship between age and outcomes after meningioma surgery. The objective of this study was to identify the relationship between age and postoperative complications after craniotomy for resection of meningioma. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients undergoing craniotomy for meningioma resection between 2005 and 2012. Multivariate analysis was used to identify associations between age and postoperative complications. RESULTS: Age >80 years is an independent risk factor for any complication (odds ratio [OR], 2.374; 95% confidence interval [CI], 1.3-4.4; P = 0.015), death within 30 days of surgery (OR, 15.7; 95% CI, 3.0-81.0; P < 0.001), and length of stay >5 days (OR, 3.2; 95% CI, 1.8-5.6; P < 0.001). CONCLUSIONS: Advanced age, particularly >80 years, is an independent predictor of morbidity and mortality in patients undergoing craniotomy for resection of meningioma. As such, it should be considered in preoperative optimization and risk stratification.

Contemporary spinal oncology treatment paradigms and outcomes for metastatic tumors to the spine: A systematic review of breast, prostate, renal, and lung metastases.

Metastatic spinal disease most frequently arises from carcinomas of the breast, lung, prostate, and kidney. Management of spinal metastases (SpM) is controversial in the literature. Recent studies advocate more aggressive surgical resection than older studies which called for radiation therapy alone, challenging previously held beliefs in conservative therapy. A literature search of the PubMed database was performed for spinal oncology outcome studies published in the English language between 2006 and 2016. Data concerning study characteristics, patient demographics, tumor origin and spinal location, treatment paradigm, and median survival were collected. The search retrieved 220 articles, 24 of which were eligible to be included. There were overall 3457 patients. Nine studies of 1723 patients discussed parameters affecting median survival time with comparison of different primary cancers. All studies found that primary cancer significantly predicted survival. Median survival time was highest for primary breast and renal cancers and lowest for prostate and lung cancers, respectively. Multiple spinal metastases, a cervical location of metastasis, and pathologic fracture each had no significant influence on survival. Survival in metastatic spinal tumors is largely driven by primary tumor type, and this should influence palliative management decisions. Surgery has been shown to greatly increase quality of life in patients who can tolerate the procedure, even in those previously treated with radiotherapy. Surgery for SpM can be used as first-line therapy for preservation of function and symptom relief. Future studies of management of SpM are warranted and primary tumor diagnosis should be studied to determine contribution to survival.

Academic Productivity of US Neurosurgery Residents as Measured by H-Index: Program Ranking with Correlation to Faculty Productivity.

Engagement in research and academic productivity are crucial components in the training of a neurosurgeon. This process typically begins in residency training. In this study, we analyzed individual resident productivity as it correlated to publications across all Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgery training programs in an attempt to identify how programs have developed and fostered a research culture and environment. We obtained a list of current neurosurgery residents in ACGME-accredited programs from the American Association of Neurological Surgeons database. An expanded PubMed and Scopus search was conducted for each resident through the present time. We tabulated all articles attributed to each resident. We then categorized the publications based on each neurosurgical subspecialty while in residency. A spreadsheet-based statistical analysis was performed. This formulated the average number of resident articles, h-indices, and most common subspecialty categories by training program. We analyzed 1352 current neurosurgery residents in 105 programs. There were a total of 10 645 publications, of which 3985 were resident first-author publications during the period of study. The most common subspecialties among all resident publications were vascular (24.9%), spine (16.9%), oncology (16.1%), pediatric (5.6%), functional (4.9%), and trauma (3.8%). The average resident published 2.9 first-author papers with average of 38.0 first-author publications by total residents at each program (range 0-241). The average h-index per resident is 2.47 ± 3.25. When comparing previously published faculty h-index program rankings against our resident h-index rankings, there is a strong correlation between the 2 datasets with a clear delineation between Top-20 productivity and that of other programs (average h-index 4.2 vs 1.7, respectively, P < .001). Increasing program size leads to a clear increase in academic productivity on both the resident and faculty level (average h-index 1.6, 1.9, 3.9 for 1, 2, and 3 resident per year programs, respectively, P < .001). Resident first-author publications correlated with recently described academic departmental productivity. Subspecialty resident publications are highest in cerebrovascular surgery. Resident research and publication is a key metric for assessing the productivity of academic neurosurgery programs and is consistent with one of the core foci of neurosurgical training.

Aberrant cervical vasculature anastomosis as cause of neck pain and successful treatment with embolization technique.

We report a patient with non-dermatomal radiating neck pain without focal neurologic deficit. Traditional workup could not identify an anatomic or biomechanical cause. Imaging showed a deep cervical vessel centered in the region of pain. Angiography later identified an aberrant anastomosis of this vessel with the occipital artery. Subsequent endovascular embolization of this arterial trunk resulted in complete pain relief.

Chiari malformation Type I surgery in pediatric patients. Part 2: complications and the influence of comorbid disease in California, Florida, and New York.

OBJECTIVE Chiari malformation Type I (CM-I) is a common and often debilitating pediatric neurological disease. However, efforts to guide preoperative counseling and improve outcomes research are impeded by reliance on small, single-center studies. Consequently, the objective of this study was to investigate CM-I surgical outcomes using population-level administrative billing data. METHODS The authors used Healthcare Cost and Utilization Project State Inpatient Databases (SID) to study pediatric patients undergoing surgical decompression for CM-I from 2004 to 2010 in California, Florida, and New York. They assessed the prevalence and influence of preoperative complex chronic conditions (CCC) among included patients. Outcomes included medical and surgical complications within 90 days of treatment. Multivariate logistic regression was used to identify risk factors for surgical complications. RESULTS A total of 936 pediatric CM-I surgeries were identified for the study period. Overall, 29.2% of patients were diagnosed with syringomyelia and 13.7% were diagnosed with scoliosis. Aside from syringomyelia and scoliosis, 30.3% of patients had at least 1 CCC, most commonly neuromuscular (15.2%) or congenital or genetic (8.4%) disease. Medical complications were uncommon, occurring in 2.6% of patients. By comparison, surgical complications were diagnosed in 12.7% of patients and typically included shunt-related complications (4.0%), meningitis (3.7%), and other neurosurgery-specific complications (7.4%). Major complications (e.g., stroke or myocardial infarction) occurred in 1.4% of patients. Among children with CCCs, only comorbid hydrocephalus was associated with a significantly increased risk of surgical complications (OR 4.5, 95% CI 2.5-8.1). CONCLUSIONS Approximately 1 in 8 pediatric CM-I patients experienced a surgical complication, whereas medical complications were rare. Although CCCs were common in pediatric CM-I patients, only hydrocephalus was independently associated with increased risk of surgical events. These results may inform patient counseling and guide future research efforts.

Chiari malformation Type I surgery in pediatric patients. Part 1: validation of an ICD-9-CM code search algorithm.

OBJECTIVE Administrative billing data may facilitate large-scale assessments of treatment outcomes for pediatric Chiari malformation Type I (CM-I). Validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code algorithms for identifying CM-I surgery are critical prerequisites for such studies but are currently only available for adults. The objective of this study was to validate two ICD-9-CM code algorithms using hospital billing data to identify pediatric patients undergoing CM-I decompression surgery. METHODS The authors retrospectively analyzed the validity of two ICD-9-CM code algorithms for identifying pediatric CM-I decompression surgery performed at 3 academic medical centers between 2001 and 2013. Algorithm 1 included any discharge diagnosis code of 348.4 (CM-I), as well as a procedure code of 01.24 (cranial decompression) or 03.09 (spinal decompression or laminectomy). Algorithm 2 restricted this group to the subset of patients with a primary discharge diagnosis of 348.4. The positive predictive value (PPV) and sensitivity of each algorithm were calculated. RESULTS Among 625 first-time admissions identified by Algorithm 1, the overall PPV for CM-I decompression was 92%. Among the 581 admissions identified by Algorithm 2, the PPV was 97%. The PPV for Algorithm 1 was lower in one center (84%) compared with the other centers (93%-94%), whereas the PPV of Algorithm 2 remained high (96%-98%) across all subgroups. The sensitivity of Algorithms 1 (91%) and 2 (89%) was very good and remained so across subgroups (82%-97%). CONCLUSIONS An ICD-9-CM algorithm requiring a primary diagnosis of CM-I has excellent PPV and very good sensitivity for identifying CM-I decompression surgery in pediatric patients. These results establish a basis for utilizing administrative billing data to assess pediatric CM-I treatment outcomes.

Simultaneous stent expansion/balloon deflation technique to salvage failed balloon remodeling.

Herniation, with possible embolization, of coils into the parent vessel following aneurysm coiling remains a frequent challenge. For this reason, balloon or stent assisted embolization remains an important technique. Despite the use of balloon remodeling, there are occasions where, on deflation of the balloon, some coils, or even the entire coil mass, may migrate. We report the successful use of a simultaneous adjacent stent deployment bailout technique in order to salvage coil prolapse during balloon remodeling in three patients. Case No 1 was a wide neck left internal carotid artery bifurcation aneurysm, measuring 9 mm×7.9 mm×6 mm with a 5 mm neck. Case No 2 was a complex left superior hypophyseal artery aneurysm, measuring 5.3 mm×4 mm×5 mm with a 2.9 mm neck. Case No 3 was a ruptured right posterior communicating artery aneurysm, measuring 4 mm×4 mm×4.5 mm with a 4 mm neck. This technique successfully returned the prolapsed coil mass into the aneurysm sac in all cases without procedural complications. The closed cell design of the Enterprise VRD (Codman and Shurtleff Inc, Raynham, Massachusetts, USA) makes it ideal for this bailout technique, by allowing the use of an 0.021 inch delivery catheter (necessary for simultaneous access) and by avoiding the possibility of an open cell strut getting caught on the deflated balloon. We hope this technique will prove useful to readers who may find themselves in a similar predicament.

Impaired weight loss in laparoscopic adjustable gastric banding patients over 50 years of age: diabetes mellitus as an independent risk factor.

INTRODUCTION: Laparoscopic adjustable gastric banding (LAGB) represents a safe and effective bariatric procedure, particularly for patients over 50. Preoperative risk factors for impaired post-LAGB excess weight loss are not well characterized for this population. This study aimed to identify demographics, characteristics or comorbidities associated with excess weight loss at 6 and 12 months postoperatively (EWL180 and EWL365, respectively) for these patients. METHODS: One hundred and seventeen LAGB patients >50 years of age from 2005 to 2014 were retrospectively reviewed for factors potentially associated with EWL180 and EWL365. Rationally selected variables chosen for analysis included age, race, gender, initial body mass index and preoperative weight loss; comorbidities assessed included hypertension, psychiatric disorders and diabetes mellitus (DM). Variables correlated with EWL180 or EWL365 on bivariate linear regression analysis (P ≤ .05) were input into multivariate linear regression analysis to confirm independent association. RESULTS: Preoperative DM (B = -9.1% EWL; 95% CI -13.6, -4.5%; P < .001) and African-American race (B = -8.8% EWL; 95% CI -17.3, -0.3%; P = .05) were independent risk factors for impaired EWL180. Only DM was a risk factor for impaired EWL365 (B = -9.7% EWL; 95% CI -17.7, -1.8%; P = .02). CONCLUSIONS: LAGB is a successful operation in patients >50 years of age. Preoperative DM is an independent risk factor for impaired EWL in this cohort.

Rule of 5: angiographic diameters of cervicocerebral arteries in children and compatibility with adult neurointerventional devices.

BACKGROUND AND PURPOSE: The safety of using adult-sized neuroendovascular devices in the smaller pediatric vasculature is not known. In this study we measure vessel diameters in the cervical and cranial circulation in children to characterize when adult-approved devices might be compatible in children. METHODS: For 54 children without vasculopathy (mean age 9.5±4.9 years (range 0.02-17.8), 20F/34M) undergoing catheter angiography, the diameters of the large vessels in the cervical and cranial circulation (10 locations, 611 total measurements) were assessed by three radiologists. Mean±SD diameter was calculated for the following age groups: 0-6 months, 1, 2, 3, 4, 5-9, 10-14, and 15-18 years. To compare with adult sizes, each vessel measurement was normalized to the respective region mean diameter in the oldest age group (15-18 years). Normalized measurements were compared with age and fitted to a segmented regression. RESULTS: Vessel diameters increased rapidly from 0 to 5 years of age (slope=0.069/year) but changed minimally beyond that (slope=0.005/year) (R(2)=0.2). The regression model calculated that, at 5 years of age, vessels would be 94% of the diameter of the oldest age group (compared with 59% at birth). In addition, most vessels in children under 5, while smaller, were still potentially large enough to be compatible with many adult devices. CONCLUSIONS: The growth curve of the cervicocerebral vasculature displays rapid growth until age 5, at which point most children's vessels are nearly adult size. By age 5, most neuroendovascular devices are size-compatible, including thrombectomy devices for stroke. Under 5 years of age, some devices might still be compatible.

Initial experience with dual-lumen balloon catheter injection for preoperative Onyx embolization of skull base paragangliomas.

OBJECT Paragangliomas are highly vascular head and neck tumors for which preoperative embolization is often considered to facilitate resection. The authors evaluated their initial experience using a dual-lumen balloon to facilitate preoperative embolization in 5 consecutive patients who underwent preoperative transarterial Onyx embolization assisted by the Scepter dual-lumen balloon catheter between 2012 and 2014. OBJECT The authors reviewed the demographic and clinical records of 5 patients who underwent Scepter-assisted Onyx embolization of a paraganglioma followed by resection between 2012 and 2014. Descriptive statistics of clinical outcomes were assessed. RESULTS Five patients (4 with a jugular and 1 with a vagal paraganglioma) were identified. Three paragangliomas were embolized in a single session, and each of the other 2 were completed in 3 staged sessions. The mean volume of Onyx used was 14.3 ml (range 6-30 ml). Twenty-seven vessels were selectively catheterized for embolization. All patients required selective embolization via multiple vessels. Two patients required sacrifice of parent vessels (1 petrocavernous internal carotid artery and 1 vertebral artery) after successful balloon test occlusion. One patient underwent embolization with Onyx-18 alone, 2 with Onyx-34 alone, and 1 with Onyx-18 and -34. In each case, migration of Onyx was achieved within the tumor parenchyma. The mean time between embolization and resection was 3.8 days (range 1-8 days). Gross-total resection was achieved in 3 (60%) patients, and the other 2 patients had minimal residual tumor. The mean estimated blood loss during the resections was 556 ml (range 200-850 ml). The mean postoperative hematocrit level change was -17.3%. Two patients required blood transfusions. One patient, who underwent extensive tumor penetration with Onyx, developed a temporary partial cranial nerve VII palsy that resolved to House-Brackmann Grade I (out of VI) at the 6-month follow-up. One patient experienced improvement in existing facial nerve weakness after embolization. CONCLUSIONS Scepter catheter-based Onyx embolization seems to be safe and effective. It was associated with excellent distal tumor vasculature penetration and holds promise as an adjunct to conventional transarterial Onyx embolization of paragangliomas. However, the ease of tumor penetration should encourage caution in practitioners who may be able to effect comparable improvement in blood loss with more conservative proximal Onyx penetration.

Minimizing bleeding complications in spinal tumor surgery with preoperative Onyx embolization via dual-lumen balloon catheter.

BACKGROUND: Intraoperative bleeding is a significant risk in surgery for highly vascular spinal tumors, but preoperative embolization can safely decrease intraoperative blood loss in extrinsic spine tumors. Onyx, widely used for cerebrovascular embolization, has been increasingly used as an embolic agent for preoperative spinal tumor embolization. The Scepter catheter, a dual-lumen balloon catheter, may improve tumor parenchymal penetration without the danger and limitations of significant embolic reflux. This may reduce bleeding risk during spinal surgery. METHODS: Eleven consecutive cases of preoperative Onyx embolization of extrinsic spinal tumors were identified, all of whom had subsequent spinal surgery. Demographic data and clinical variables were collected. Patients were divided into Scepter (n=6) and non-Scepter (n=5) groups. The Mann-Whitney U test was used to compare continuous outcome variables and the Fisher exact test was used to compare categorical variables. RESULTS: Estimated blood loss in the Scepter group was significantly lower than in the non-Scepter group (584±124 vs 2400±738 mL, p=0.004). The volume of intraoperative transfusion was also significantly lower (1.2±0.4 vs 5.8±1.7 units, p=0.004). There was no significant difference in the number of vessels embolized, vials of Onyx used, use of coiling adjunct, contrast load, radiation dose, or fluoroscopy time per pedicle (p>0.05). CONCLUSIONS: The addition of the Scepter catheter to preoperative Onyx embolization is safe and feasible. In this small series, the Scepter catheter was associated with a reduction of intraoperative bleeding by 76% and a 79% lower transfusion volume. This was not accompanied by any unwanted increase in vials of Onyx used, contrast load, radiation dose, or fluoroscopy time.

Pediatric Acute Stroke Protocol Activation in a Children's Hospital Emergency Department.

BACKGROUND AND PURPOSE: Pediatric acute stroke teams are a new phenomenon. We sought to characterize the final diagnoses of children with brain attacks in the emergency department where the pediatric acute stroke protocol was activated and to describe the time to neurological evaluation and neuroimaging. METHODS: Clinical and demographic information was obtained from a quality improvement database and medical records for consecutive patients (age, ≤20 years) presenting to a single institution's pediatric emergency department where the acute stroke protocol was activated between April 2011 and October 2014. Stroke protocol activation means that a neurology resident evaluates the child within 15 minutes, and urgent magnetic resonance imaging is available. RESULTS: There were 124 stroke alerts (age, 11.2±5.2 years; 63 boys/61 girls); 30 were confirmed strokes and 2 children had a transient ischemic attack. Forty-six of 124 (37%) cases were healthy children without any significant medical history. Nonstroke neurological emergencies were found in 17 children (14%); the majority were meningitis/encephalitis (n=5) or intracranial neoplasm (n=4). Other common final diagnoses were complex migraine (17%) and seizure (15%). All children except 1 had urgent neuroimaging. Magnetic resonance imaging was the first study in 76%. The median time from emergency department arrival to magnetic resonance imaging was 94 minutes (interquartile range, 49-151 minutes); the median time to computed tomography was 59 minutes (interquartile range, 40-112 minutes). CONCLUSIONS: Of pediatric brain attacks, 24% were stroke, 2% were transient ischemic attack, and 14% were other neurological emergencies. Together, 40% had a stroke or other neurological emergency, underscoring the need for prompt evaluation and management of children with brain attacks.

Posterior odontoid process angulation in pediatric Chiari I malformation: an MRI morphometric external validation study.

OBJECT Osseous anomalies of the craniocervical junction are hypothesized to precipitate the hindbrain herniation observed in Chiari I malformation (CM-I). Previous work by Tubbs et al. showed that posterior angulation of the odontoid process is more prevalent in children with CM-I than in healthy controls. The present study is an external validation of that report. The goals of our study were 3-fold: 1) to externally validate the results of Tubbs et al. in a different patient population; 2) to compare how morphometric parameters vary with age, sex, and symptomatology; and 3) to develop a correlative model for tonsillar ectopia in CM-I based on these measurements. METHODS The authors performed a retrospective review of 119 patients who underwent posterior fossa decompression with duraplasty at the Monroe Carell Jr. Children's Hospital at Vanderbilt University; 78 of these patients had imaging available for review. Demographic and clinical variables were collected. A neuroradiologist retrospectively evaluated preoperative MRI examinations in these 78 patients and recorded the following measurements: McRae line length; obex displacement length; odontoid process parameters (height, angle of retroflexion, and angle of retroversion); perpendicular distance to the basion-C2 line (pB-C2 line); length of cerebellar tonsillar ectopia; caudal extent of the cerebellar tonsils; and presence, location, and size of syringomyelia. Odontoid retroflexion grade was classified as Grade 0, > 90°; Grade I,85°-89°; Grade II, 80°-84°; and Grade III, < 80°. Age groups were defined as 0-6 years, 7-12 years, and 13-17 years at the time of surgery. Univariate and multivariate linear regression analyses, Kruskal-Wallis 1-way ANOVA, and Fisher's exact test were performed to assess the relationship between age, sex, and symptomatology with these craniometric variables. RESULTS The prevalence of posterior odontoid angulation was 81%, which is almost identical to that in the previous report (84%). With increasing age, the odontoid height (p < 0.001) and pB-C2 length (p < 0.001) increased, while the odontoid process became more posteriorly inclined (p = 0.010). The pB-C2 line was significantly longer in girls (p = 0.006). These measurements did not significantly correlate with symptomatology. Length of tonsillar ectopia in pediatric CM-I correlated with an enlarged foramen magnum (p = 0.023), increasing obex displacement (p = 0.020), and increasing odontoid retroflexion (p < 0.001). CONCLUSIONS Anomalous bony development of the craniocervical junction is a consistent feature of CM-I in children. The authors found that the population at their center was characterized by posterior angulation of the odontoid process in 81% of cases, similar to findings by Tubbs et al. (84%). The odontoid process appeared to lengthen and become more posteriorly inclined with age. Increased tonsillar ectopia was associated with more posterior odontoid angulation, a widened foramen magnum, and an inferiorly displaced obex.

Complications and Resource Use Associated With Surgery for Chiari Malformation Type 1 in Adults: A Population Perspective.

BACKGROUND: Outcomes research on Chiari malformation type 1 (CM-1) is impeded by a reliance on small, single-center cohorts. OBJECTIVE: To study the complications and resource use associated with adult CM-1 surgery using administrative data. METHODS: We used a recently validated International Classification of Diseases, Ninth Revision, Clinical Modification code algorithm to retrospectively study adult CM-1 surgeries from 2004 to 2010 in California, Florida, and New York using State Inpatient Databases. Outcomes included complications and resource use within 30 and 90 days of treatment. We used multivariable logistic regression to identify risk factors for morbidity and negative binomial models to determine risk-adjusted costs. RESULTS: We identified 1947 CM-1 operations. Surgical complications were more common than medical complications at both 30 days (14.3% vs 4.4%) and 90 days (18.7% vs 5.0%) postoperatively. Certain comorbidities were associated with increased morbidity; for example, hydrocephalus increased the risk for surgical (odds ratio [OR] = 4.51) and medical (OR = 3.98) complications. Medical but not surgical complications were also more common in older patients (OR = 5.57 for oldest vs youngest age category) and male patients (OR = 3.19). Risk-adjusted hospital costs were $22530 at 30 days and $24852 at 90 days postoperatively. Risk-adjusted 90-day costs were more than twice as high for patients experiencing surgical ($46264) or medical ($65679) complications than for patients without complications ($18880). CONCLUSION: Complications after CM-1 surgery are common, and surgical complications are more frequent than medical complications. Certain comorbidities and demographic characteristics are associated with increased risk for complications. Beyond harming patients, complications are also associated with substantially higher hospital costs. These results may help guide patient management and inform decision making for patients considering surgery.

Validation of an International Classification of Diseases, Ninth Revision Code Algorithm for Identifying Chiari Malformation Type 1 Surgery in Adults.

BACKGROUND: The use of administrative billing data may enable large-scale assessments of treatment outcomes for Chiari Malformation type I (CM-1). However, to utilize such data sets, validated International Classification of Diseases, Ninth Revision (ICD-9-CM) code algorithms for identifying CM-1 surgery are needed. OBJECTIVE: To validate 2 ICD-9-CM code algorithms identifying patients undergoing CM-1 decompression surgery. METHODS: We retrospectively analyzed the validity of 2 ICD-9-CM code algorithms for identifying adult CM-1 decompression surgery performed at 2 academic medical centers between 2001 and 2013. Algorithm 1 included any discharge diagnosis code of 348.4 (CM-1), as well as a procedure code of 01.24 (cranial decompression) or 03.09 (spinal decompression, or laminectomy). Algorithm 2 restricted this group to patients with a primary diagnosis of 348.4. The positive predictive value (PPV) and sensitivity of each algorithm were calculated. RESULTS: Among 340 first-time admissions identified by Algorithm 1, the overall PPV for CM-1 decompression was 65%. Among the 214 admissions identified by Algorithm 2, the overall PPV was 99.5%. The PPV for Algorithm 1 was lower in the Vanderbilt (59%) cohort, males (40%), and patients treated between 2009 and 2013 (57%), whereas the PPV of Algorithm 2 remained high (≥99%) across subgroups. The sensitivity of Algorithms 1 (86%) and 2 (83%) were above 75% in all subgroups. CONCLUSION: ICD-9-CM code Algorithm 2 has excellent PPV and good sensitivity to identify adult CM-1 decompression surgery. These results lay the foundation for studying CM-1 treatment outcomes by using large administrative databases.

Race as a predictor of delay from diagnosis to endarterectomy in clinically significant carotid stenosis.

OBJECTIVE: Prompt carotid endarterectomy (CEA) in clinically significant carotid stenosis is important in the prevention of neurologic sequelae. The greatest benefit from surgery is obtained by prompt revascularization on diagnosis. It has been demonstrated that black patients both receive CEA less frequently than white patients do and experience worse postoperative outcomes. We sought to test our hypothesis that black race is an independent risk factor for a prolonged time from sonographic diagnosis of carotid stenosis warranting surgery to the day of operation (TDO). METHODS: From 1998 to 2013 at a single institution, 166 CEA patients were retrospectively reviewed using Synthetic Derivative, a de-identified electronic medical record. Factors potentially affecting TDO, including demographics, preoperative cardiac stress testing, degree of stenosis, smoking status, and comorbidities, were noted. Multivariate analysis was performed on variables that trended with prolonged TDO on univariate analysis (P < .10) to determine independent (P < .05) predictors of TDO. Subgroup analyses were further performed on the symptomatic and asymptomatic stenosis cohorts. RESULTS: There were 32 black patients and 134 white patients studied; the mean TDO was 78 ± 17 days vs 33 ± 3 days, respectively (P < .001). In addition to the need for preoperative cardiac stress testing, black race was the only variable that demonstrated a trend with (P < .10) or was an independent risk factor for (P < .05) prolonged TDO among all patients (B = 42 days; P < .001) and within the symptomatic (B = 35 days; P = .08) and asymptomatic (B = 35 days; P = .003) cohorts. On Kaplan-Meier analysis, black patients in each stratum of symptomatology (all, symptomatic, and asymptomatic patients) experienced prolonged TDO (log-rank, P < .03 for all three groups). CONCLUSIONS: Black race is a risk factor for a temporal delay in CEA for carotid stenosis. Awareness of this disparity may help surgeons avoid undesirable delays in operation for their black patients.