Vijay M. Ravindra

Unplanned reoperation after lumbopelvic fixation with S-2 alar-iliac screws or iliac bolts.

OBJECT S-2 alar-iliac (S2AI) screws are an attractive alternative to conventional fixation with iliac bolts because they are lower profile, require less muscle dissection, and have greater pullout strength. Few studies, however, compare outcomes between these techniques. METHODS The authors conducted a retrospective cohort study of consecutive adult patients at a single institution from December 2009 to March 2012 who underwent lumbopelvic fixation using S2AI screws or iliac bolts. Medical records were reviewed for patients with clinical failure, defined as an unplanned reoperation because of instrumentation failure and/or wound-related complications. Univariate, multivariate, and survival analyses were used to compare patients who required reoperation with those who did not. Method of pelvic fixation was the main predictor variable of interest, and the authors adjusted for potential confounding risk factors. RESULTS Of the 60 patients included, 23 received S2AI screws. Seventeen patients (28%) underwent an osteotomy. The mean follow-up was 22 months. A Kaplan-Meier survival model was used to evaluate the time to reoperation from the initial placement of lumbopelvic instrumentation. The failure-free rate was 96.6% at 6 months, 87.0% at 1 year, and 73.5% at 2 years. Reoperation was more common in patients with iliac bolts than in those with S2AI screws (13 vs 2; p = 0.031). Univariate analysis identified potential risk factors for unplanned reoperation, including use of iliac bolts (p = 0.031), absence of L5-S1 interbody graft (p = 0.048), previous lumbar fusion (p = 0.034), and pathology other than degenerative disease or scoliosis (p = 0.034). After adjusting for other risk factors, multivariate analysis revealed that the use of S2AI screws (OR 8.1 [1.5-73.5]; p = 0.030) was the only independent predictor for preventing unplanned reoperation. CONCLUSIONS Both S2AI screws and iliac bolts were effective at improving fusion rates at the lumbosacral junction. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for wound-related complications and instrumentation failures than the use of iliac bolts.

The Need for Cost-Effective Neurosurgical Innovation—A Global Surgery Initiative

The authors discuss the unmet needs for neurosurgical care around the world and some of the innovative work being done to address this need. The growing demonstration of surgical innovation and cost-effective technology represents an opportunity within neurosurgery to achieve the goal of making surgical care more accessible to the global population.

Molecular features assisting in diagnosis, surgery, and treatment decision making in low-grade gliomas.

The preferred management of suspected low-grade gliomas (LGGs) has been disputed, and the implications of molecular changes for medical and surgical management of LGGs are important to consider. Current strategies that make use of molecular markers and imaging techniques and therapeutic considerations offer additional options for management of LGGs. Mutations in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes suggest a role for this abnormal metabolic pathway in the pathogenesis and progression of these primary brain tumors. Use of magnetic resonance spectroscopy can provide preoperative detection of IDH-mutated gliomas and affect surgical planning. In addition, IDH1 and IDH2 mutation status may have an effect on surgical resectability of gliomas. The IDH-mutated tumors exhibit better prognosis throughout every grade of glioma, and mutation may be an early genetic event, preceding lineage-specific secondary and tertiary alterations that transform LGGs into secondary glioblastomas. The O6-methylguanine-DNAmethyltransferase (MGMT) promoter methylation and 1p19q codeletion status can predict sensitivity to chemotherapy and radiation in low- and intermediate-grade gliomas. Thus, these recent advances, which have led to a better understanding of how molecular, genetic, and epigenetic alterations influence the pathogenicity of the different histological grades of gliomas, can lead to better prognostication and may lead to specific targeted surgical interventions and medical therapies.

Simpson Grade I-III Resection of Spinal Atypical (World Health Organization Grade II) Meningiomas is Associated With Symptom Resolution and Low Recurrence

BACKGROUND Because of their rarity, outcomes regarding spinal atypical meningiomas (AMs) remain unclear. OBJECTIVE To describe the recurrence rate and postoperative outcomes after resection of spinal AMs, and to discuss an appropriate resection strategy and adjuvant therapy for spinal AMs. METHODS Data from all patients who presented with spinal AMs to 2 tertiary referral centers between 1998 and 2013 were obtained by chart review. RESULTS From 102 patients with spinal meningioma, 20 AM tumors (7 cervical, 11 thoracic, 2 thoracolumbar) were identified in 18 patients (median age, 50 years [range, 19-75] at time of resection; 11% male; median follow-up, 32 months [range, 1-179] after resection). Before resection, patients had sensory deficits (70%), pain (70%), weakness (60%), ataxia (50%), spasticity (65%), and incontinence (35%). One tumor presented asymptomatically. Simpson grade I, II, III, and IV resection were achieved in 3 (15%), 13 (65%), 2 (10%), and 2 (10%) tumors, respectively. One patient that underwent Simpson grade III resection received adjuvant radiation therapy. After Simpson grade I-III or gross total resection, no tumors recurred (0%; confidence interval, 0%-17.6%). After Simpson grade IV resection, 1 tumor recurred (50%; confidence interval, 1.3%-98.7%). With the exception of 1 patient who had bilateral paraplegia perioperatively, all other patients experienced improvement of preoperative symptoms after surgery (median time, 3.6 months [range, 1-13] after resection). CONCLUSION Despite published cases suggesting an aggressive clinical course for spinal AMs, this series of spinal AMs reports that gross total resection without adjuvant radiation therapy resulted in symptom resolution and low recurrence.

Vitamin D Levels and 1-Year Fusion Outcomes in Elective Spine Surgery: A Prospective Observational Study.

Study Design. Prospective observational study. Objective. To investigate the association of perioperative vitamin D levels and nonunion rates and time to fusion in patients undergoing elective spine fusion. Summary of Background Data. Although there is a clear link between bone mineral density and the risk of osteoporosis, it is unclear whether low vitamin D levels affect rates and timing of spinal fusion. Methods. Serum 25-OH vitamin D levels were measured perioperatively in adults undergoing elective spinal fusion between 2011 and 2012. Vitamin D levels <20 ng/mL were considered deficient. Univariate and multivariate logistic regression were performed to identify independent predictors of pseudarthrosis/nonunion within a minimum follow-up period of 12 months. Kaplan-Meier analysis was used to compare time to fusion between groups. Results. Of the 133 patients, 31 (23%) demonstrated vitamin D deficiency. Mean patient age was 57 ± 13 years; 44% were female and 94% were Caucasian. The cervical spine was fused in 49%, the lumbar spine in 47%, and the thoracic spine in 4%. Mean construct length was 2 levels (range 1–16). At 12-month follow-up, 112/133 (84%) patients demonstrated fusion (median time to fusion 8.4 mo). Nonunion at 12 months was associated with vitamin D deficiency (20% of patients with adequate vitamin D level vs. 38% of vitamin D-deficient patients, P = 0.063). Kaplan-Meier survival analysis demonstrated time to fusion was significantly longer in the vitamin D-deficient group (12 vs. 6 mo, P = 0.001). On multivariate analysis, vitamin D deficiency was an independent predictor of nonunion (odds ratio 3.449, P = 0.045) when adjusted for age, sex, obesity, fusion length, location, graft type, smoking, and bone morphogenetic protein use. Conclusion. Vitamin D levels may affect nonunion rate and time to fusion. These results offer insight into the importance of the metabolic milieu for bony fusion as well as a potential avenue for therapeutic intervention. Level of Evidence: 3

Prevalence of Vitamin D Deficiency in Patients Undergoing Elective Spine Surgery: A Cross-Sectional Analysis

OBJECTIVE Decreased bone density secondary to osteoporosis and osteomalacia represents a significant risk factor for bony fracture and spinal instrumentation failure. We evaluated the incidence of vitamin D deficiency in patients undergoing elective spinal instrumentation to investigate which patient-level risk factors are associated with deficient vitamin D levels. METHODS Serum 25-OH vitamin D levels were evaluated postoperatively (<72 hours) in patients undergoing elective spinal fusion from 2011 through 2012. Patients >18 years with a diagnosis of degenerative spinal spondylosis or spinal instability treated with spinal fusion were included. Risk factors for vitamin D deficiency (<20 ng/mL) were analyzed using univariate and multiple logistic regression to identify independent predictors of deficiency. RESULTS The mean preoperative neck and Oswestry disability indexes of the 230 consecutive patients (mean, 57 ± 13.9 years) were 21.0 ± 9.8 and 22.2 ± 8.5, respectively. Mean 25-OH vitamin D level was 25.9 ± 12.4 ng/mL (range, 6-77 ng/mL). Sixty-nine (30.0%) patients had laboratory-confirmed vitamin D deficiency and 89 (38.9%) had laboratory-confirmed vitamin D insufficiency (20-30 ng/mL). The risk of vitamin D deficiency was greater in men (odds ratio [OR] 2.53; P = 0.009), patients aged 40-60 years (OR 2.45; P = 0.018), and those who had body mass index >40 (OR 7.55; P = 0.004), an existing diagnosis of diabetes (OR 3.29; P = 0.019), or no vitamin D supplementation (OR 4.96; P = 0.043). CONCLUSIONS Vitamin D deficiency was common in patients with degenerative spondylosis undergoing spinal fusion. Middle-aged patients, men, the morbidly obese, those with a history of diabetes, and those with no history of supplementation had a higher incidence of vitamin D deficiency.

Treatment Practices and Outcomes After Blunt Cerebrovascular Injury in Children

BACKGROUND Pediatric blunt cerebrovascular injury (BCVI) lacks accepted treatment algorithms, and postinjury outcomes are ill defined. OBJECTIVE To compare treatment practices among pediatric trauma centers and to describe outcomes for available treatment modalities. METHODS Clinical and radiographic data were collected from a patient cohort with BCVI between 2003 and 2013 at 4 academic pediatric trauma centers. RESULTS Among 645 pediatric patients evaluated with computed tomography angiography for BCVI, 57 vascular injuries (82% carotid artery, 18% vertebral artery) were diagnosed in 52 patients. Grade I (58%) and II (23%) injuries accounted for most lesions. Severe intracranial or intra-abdominal hemorrhage precluded antithrombotic therapy in 10 patients. Among the remaining patients, primary therapy was an antiplatelet agent in 14 (33%), anticoagulation in 8 (19%), endovascular intervention in 3 (7%), open surgery in 1 (2%), and no treatment in 16 (38%). Among 27 eligible grade I injuries, 16 (59%) were not treated, and the choice to not treat varied significantly among centers (P < .001). There were no complications from medical management. Glasgow Coma Scale (GCS) score <8 and increasing injury grade were predictors of injury progression (P = .001 and .004, respectively). Poor GCS score (P = .02), increasing injury grade (P = .03), and concomitant intracranial injury (P = .02) correlated with increased risk of mortality. Treatment modality did not correlate with progression of vascular injury or mortality. CONCLUSION Treatment of BCVI with antiplatelet or anticoagulant therapy is safe and may confer modest benefit. Nonmodifiable factors, including presenting GCS score, vascular injury grade, and additional intracranial injury, remain the most important predictors of poor outcome. ABBREVIATIONS ATT, antithrombotic therapyBCVI, blunt cerebrovascular injuryCTA, computed tomography angiographyGCS, Glasgow Coma Scale.

Unilateral fixation for treatment of occipitocervical instability in children with congenital vertebral anomalies of the craniocervical junction.

OBJECT Patients with occipitocervical (OC) instability from congenital vertebral anomalies (CVAs) of the craniocervical junction (CCJ) often have bony abnormalities that make instrumentation placement difficult. Within this patient population, some bilateral instrumentation constructs either fail or are not feasible, and a unilateral construct must be used. The authors describe the surgical management and outcomes of this disorder in patients in whom unilateral fixation constructs were used to treat OC instability. METHODS From a database of OC fusion procedures, the authors identified patients who underwent unilateral fixation for the management of OC instability. Patient characteristics, surgical details, and radiographic outcomes were reviewed. In each patient, CT scans were performed at least 4 months after surgery to evaluate for fusion. RESULTS Eight patients with CVAs of the CCJ underwent unilateral fixation for the treatment of OC instability. For 4 patients, the procedure occurred after a bilateral OC construct failed or infection forced hardware removal. For the remainder, it was the primary procedure. Two patients required reoperation for hardware revision and 1 developed nonunion requiring revision of the bone graft. Ultimately, 7 patients demonstrated osseous fusion on CT scans and 1 had a stable fibrous union. CONCLUSIONS These findings demonstrate that a unilateral OC fixation is effective for the treatment of OC instability in children with CVAs of the CCJ in whom bilateral screw placement fails or is not feasible.

Primary osseous tumors of the pediatric spinal column: review of pathology and surgical decision making

Spinal column tumors are rare in children and young adults, accounting for only 1% of all spine and spinal cord tumors combined. They often present diagnostic and therapeutic challenges. In this article, the authors review the current management of primary osseous tumors of the pediatric spinal column and highlight diagnosis, management, and surgical decision making.

Management of intracranial pathology during pregnancy: Case example and review of management strategies

Background: Intracranial tumors during pregnancy are uncommon, and they present an interesting challenge to both the neurosurgeon and the obstetrician. Special considerations must be made in every aspect of care. The authors use the rare case of a 27-year-old pregnant female with suspected pineal region tumor eventually diagnosed as a thalamic region ganglioglioma to review the current literature on management of pathology in this unique patient population. Case Description: A 27-year-old female who was 26 weeks pregnant presented to her obstetrician with complaints of headaches, blurriness of vision, and left-sided numbness and tingling. She was diagnosed with 1-cm mass in the pineal region and obstructive hydrocephalus. She initially underwent an endoscopic third ventriculostomy with biopsy of what appeared grossly to be a thalamic mass. The child was delivered via cesarean section at 39 weeks. Serial postpartum imaging demonstrated increasing tumor size and enhancement, which led the authors to proceed with subtotal resection via a supracerebellar infratentorial approach with stereotactic neuronavigation. Tissue specimens obtained for pathological analysis resulted in a revised diagnosis of World Health Organization (WHO) grade II ganglioglioma. Conclusions: Pregnancy presents a challenge for any patient requiring neurosurgical intervention. We present an interesting case example with a rare central nervous system neoplasm and discuss the management of intracranial pathology in pregnant patients.