Sandi Lam

Outcomes of cranioplasty following decompressive craniectomy in the pediatric population.

Cranioplasty is routinely performed following decompressive craniectomy in both adult and pediatric populations. In adults, this procedure is associated with higher rates of complications than is elective cranial surgery. This study is a review of the literature describing risk factors for complications after cranioplasty surgery in pediatric patients. A systematic search of PubMed, Cochrane, and SCOPUS databases was undertaken. Articles were selected based on their titles and abstracts. Only studies that focused on a pediatric population were included; case reports were excluded. Studies in which the authors assessed bone flap storage method, timing of cranioplasty, material used (synthetic vs autogenous), skull defect size, and/or complication rates (bone resorption and surgical site infection) were selected for further analysis. Eleven studies that included a total of 441 cranioplasties performed in the pediatric population are included in this review. The findings are as follows: 1) Based on analysis of pooled data, using cryopreserved bone flaps during cranioplasty may lead to a higher rate of bone resorption and lower rate of infection than using bone flaps stored at room temperature. 2) In 3 of 4 articles describing the effect of time between craniectomy and cranioplasty on complication rate, the authors found no significant effect, while in 1 the authors found that the incidence of bone resorption was significantly lower in children who had undergone early cranioplasty. Pooling of data was not possible for this analysis. 3) There are insufficient data to assess the effect of cranioplasty material on complication rate when considering only cranioplasties performed to repair decompressive craniectomy defects. However, when considering cranioplasties performed for any indication, those in which freshly harvested autograft is used may have a lower rate of resorption than those in which stored autograft is used. 4) There is no appreciable effect of craniectomy defect size or patient age on complication rate. There is a paucity of articles describing outcomes and complications following cranioplasty in children and adolescents. However, based on the studies examined in this systematic review, there are reasons to suspect that method of flap preservation, timing of surgery, and material used may be significant. Larger prospective and retrospective studies are needed to shed more light on this important issue.

The impact of attention deficit hyperactivity disorder on recovery from mild traumatic brain injury

OBJECT Attention deficit hyperactivity disorder (ADHD) and traumatic brain injury (TBI) are significant independent public health concerns in the pediatric population. This study explores the impact of a premorbid diagnosis of ADHD on outcome following mild TBI. METHODS The charts of all patients with a diagnosis of mild closed head injury (CHI) and ADHD who were admitted to Childrens Hospital of Pittsburgh between January 2003 and December 2010 were retrospectively reviewed after institutional review board approval was granted. Patient demographics, initial Glasgow Coma Scale (GCS) score, hospital course, and Kings Outcome Scale for Childhood Head Injury (KOSCHI) score were recorded. The results were compared with a sample of age-matched controls admitted with a diagnosis of CHI without ADHD. RESULTS Forty-eight patients with mild CHI and ADHD, and 45 patients with mild CHI without ADHD were included in the statistical analysis. Mild TBI due to CHI was defined as an initial GCS score of 13-15. The ADHD group had a mean age of 12.2 years (range 6-17 years), and the control group had a mean age of 11.14 years (range 5-16 years). For patients with mild TBI who had ADHD, 25% were moderately disabled (KOSCHI Score 4b), and 56% had completely recovered (KOSCHI Score 5b) at follow-up. For patients with mild TBI without ADHD, 2% were moderately disabled and 84% had completely recovered at follow-up (p < 0.01). Patients with ADHD were statistically significantly more disabled after mild TBI than were control patients without ADHD, even when controlling for age, sex, initial GCS score, hospital length of stay, length of follow-up, mechanism of injury, and presence of other (extracranial) injury. CONCLUSIONS Patients who sustain mild TBIs in the setting of a premorbid diagnosis of ADHD are more likely to be moderately disabled by the injury than are patients without ADHD.

History of synthetic materials in alloplastic cranioplasty

When faced with calvarial defects, surgeons have long searched for repair materials. General criteria include ease of use, low cost, availability, cosmetic shape, and osteointegrative potential. While autologous bone is widely used and favored in contemporary reconstructive procedures, synthetic alternatives have been used throughout history and are necessary in current practice for select cases when autograft reconstruction is not an option (such as cases with severe bony comminution, bone graft resorption, infection, and limited donor site options). For centuries, surgeons have experimented with metals, ceramics, plastics, and later, resorbable polymers. This paper provides a tour of the materials that have been used and experimented with throughout the history of alloplastic cranioplasty.

Measuring Surgical Outcomes in Cervical Spondylotic Myelopathy Patients Undergoing Anterior Cervical Discectomy and Fusion: Assessment of Minimum Clinically Important Difference

Object The concept of minimum clinically important difference (MCID) has been used to measure the threshold by which the effect of a specific treatment can be considered clinically meaningful. MCID has previously been studied in surgical patients, however few studies have assessed its role in spinal surgery. The goal of this study was to assess the role of MCID in patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). Methods Data was collected on 30 patients who underwent ACDF for CSM between 2007 and 2012. Preoperative and 1-year postoperative Neck Disability Index (NDI), Visual-Analog Scale (VAS), and Short Form-36 (SF-36) Physical (PCS) and Mental (MCS) Component Summary PRO scores were collected. Five distribution- and anchor-based approaches were used to calculate MCID threshold values average change, change difference, receiver operating characteristic curve (ROC), minimum detectable change (MDC) and standard error of measurement (SEM). The Health Transition Item of the SF-36 (HTI) was used as an external anchor. Results Patients had a significant improvement in all mean physical PRO scores postoperatively (p<0.01) NDI (29.24 to 14.82), VAS (5.06 to 1.72), and PCS (36.98 to 44.22). The five MCID approaches yielded a range of values for each PRO: 2.00–8.78 for PCS, 2.06–5.73 for MCS, 4.83–13.39 for NDI, and 0.36–3.11 for VAS. PCS was the most representative PRO measure, presenting the greatest area under the ROC curve (0.94). MDC values were not affected by the choice of anchor and their threshold of improvement was statistically greater than the chance of error from unimproved patients. Conclusion SF-36 PCS was the most representative PRO measure. MDC appears to be the most appropriate MCID method. When MDC was applied together with HTI anchor, the MCID thresholds were: 13.39 for NDI, 3.11 for VAS, 5.56 for PCS and 5.73 for MCS.

Patient and treatment factors associated with survival among adult glioblastoma patients: A USA population-based study from 2000–2010

In this study, we utilized the USA surveillance, epidemiology, and end results (SEER) database to examine factors influencing survival of glioblastoma multiforme (GBM) patients. GBM is the most common primary malignant brain tumor in adults and despite advances in treatment, prognosis remains poor. Using the SEER database, we defined a cohort of adult patients for the years 2000-2009 with confirmed GBM and minimum follow-up of 12 months. A total of 14,675 patients with GBM met the inclusion criteria. Demographic, clinical, and treatment variables were examined. Death was the primary outcome. Median survival time was 11 months. Patients had increasingly longer survival over the decade span. We found, on multivariate analysis, that significantly worse survival was associated with age >75 years, male sex, unmarried status, and non-Hispanic Caucasian race/ethnicity. Patients in the Northeast had a significantly lower risk of mortality. Patients with tumors that were non-lateralized and >3 cm fared worse. Patients who did not receive adjuvant radiation also had worse outcomes. Gross total resection imparted a survival advantage for patients compared to biopsy or partial resection. Thus, this report adds to the growing body of literature supporting the positive role of maximal resection on patient survival.

Pediatric endoscopic third ventriculostomy: a population-based study

OBJECT Endoscopic third ventriculostomy (ETV) is an alternative to ventriculoperitoneal shunting for hydrocephalus treatment. Choice of treatment options raises questions about which patients are likely to benefit from ETV. The authors performed a population-based analysis using an administrative claims database, examining current practice and outcomes for pediatric patients in the US. METHODS The authors queried the MarketScan (Truven Health Analytics) database for Current Procedural Terminology codes corresponding to ETV and ventriculoperitoneal shunting from 2003 to 2011; they included patients 19 years or younger and extracted data from initial and subsequent hospitalizations. Hydrocephalus etiology was classified with ICD-9-CM coding. ETV failure was defined as any subsequent ETV or shunt procedure. RESULTS Five hundred one patients underwent ETV. Of these, 46% were female. The mean age was 8.7 ± 6.4 years (± SD). The mean follow-up was 1.9 ± 1.8 years. Etiology of hydrocephalus was primarily tumor (41.7%) and congenital/aqueductal stenosis (24.4%). ETV was successful in 354 patients (71%). The mean time to failure was 109.9 ± 233 days. Of the 147 patients with ETV failure, 35 (24%) underwent repeat ETV and 112 (76%) had shunt placement. Patients in age groups 0 to < 6 months and 6 months to < 1 year had a significantly higher rate of ETV failure than those 10-19 years (HR 2.9, p = 0.05; and HR 2.3, p = 0.001, respectively). History of prior shunt was associated with higher risk of failure (HR 2.5, p < 0.001). There were no significant associations between hydrocephalus etiology and risk of failure. A second wave of failures occurred at 2.5-3.5 years postoperative in tumor and congenital/aqueductal stenosis patients; this was not observed in other etiology groups. CONCLUSIONS This study represents a cross-section of nationwide ETV practice over 9 years. ETV success was more likely among children 1 year and older and those with no history of prior shunt.

Clinical Outcomes of Microendoscopic Foraminotomy and Decompression in the Cervical Spine

OBJECTIVE Few reports have addressed long-term outcomes, as well as the safety and efficacy of the cervical microendoscopic foraminotomy (CMEF) and cervical microendoscopic diskectomy (CMED) procedures used in modern spine practice to treat degenerative disease of the cervical spine. Accordingly, we present long-term outcomes from a cohort of patients treated for foraminal stenosis or disk herniation with the CMEF or CMED procedure, respectively. METHODS A total of 38 patients were included in the study, with a mean follow-up of 24.47 ± 12.84 months. Patients were monitored prospectively with questionnaires consisting of a visual analog scale for the neck (VASN) and arm (VASA), and a neck disability index (NDI) form. Operative time, estimated blood loss, and hospitalization stay also were collected. Data were analyzed with Microsoft Office Excel 2007. RESULTS The mean 1 year follow-up scores all showed statistically significant improvements: NDI (P = 0.0019), VASN (P = 0.0017), VASA (P ≤ 0.0001). Similar results were seen at 2-year follow-up: NDI (P = 0.0011), VASN (P = 0.0022), and VASA (P ≤ 0.0001); and at 3- to 6-year follow-up: NDI (P = 0.0015), VASN (P = 0.0200), and VASA (P = 0.0034). The average operation time, hospitalization stay, and estimated blood loss were 154.27 ± 26.79 minutes, 21.22 ± 14.23 hours, and 27.92 mL, respectively. There were no statistically significant differences when patients were compared by age (over 50 vs. under 50), operative level (above C6 vs. below C6), or sex. One complication was reported in this study consisting of duratomy, which required no further intervention. CONCLUSION Posterior CMEF and CMED are safe and effective procedures for minimally invasive decompression in the cervical spine.

The safety and efficacy of use of low-molecular-weight heparin in pediatric neurosurgical patients

OBJECT Low-molecular-weight heparins (LMWHs), mainly enoxaparin, offer several advantages over standard anticoagulation therapies such as unfractionated heparin and warfarin, including predictable pharmacokinetics, minimal monitoring, and subcutaneous administration. The purpose of this study was to determine the safety and efficacy of LMWHs in pediatric neurosurgical patients. METHODS A retrospective study was performed with patients 18 years old or younger who were admitted to the Pediatric Neurosurgery Service at Texas Childrens Hospital and treated with LMWH for either therapeutic or prophylactic purposes between March 1, 2011, and December 30, 2013. Demographic and clinical features and outcomes were recorded. RESULTS LMWH was administered for treatment of venous thromboembolic events (VTEs) in 17 children and for prophylaxis in 24 children. Clinical resolution of VTEs occurred in 100% (17 of 17) of patients receiving therapeutic doses of LMWH. No patient receiving prophylactic doses of LMWH developed a new VTE. Major or minor bleeding complications occurred in 18% (3 of 17 children) and 4% (1 of 24 children) of those receiving therapeutic and prophylactic doses, respectively. All 4 patients who experienced hemorrhagic complications had other bleeding risk factors-i.e., coagulopathies and antiplatelet medications. CONCLUSIONS LMWH seems to be safe and efficacious for both management and prophylaxis of VTEs in pediatric neurosurgery. However, pediatric practitioners should be aware of higher risk for bleeding complications with increasing doses of LMWH, especially in patients with preexisting bleeding disorders or concurrent use of antiplatelet agents.

Microendoscopic decompression for cervical spondylotic myelopathy

OBJECT Cervical spondylotic myelopathy (CSM) is a common cervical degenerative disease that affects the elderly population. Spinal cord decompression is achieved through various anterior and posterior approaches including anterior cervical decompression and fusion, laminectomy, laminoplasty, and combined approaches. The authors describe another option, minimally invasive endoscopically assisted decompression of stenosis (MEDS), which obviates the need for muscle dissection and disruption of the posterior tension band, a cause of postlaminectomy kyphosis. METHODS The authors conducted a retrospective study of 10 patients with CSM who underwent MEDS from January 2002 through July 2012. Data were collected on demographics, preoperative and postoperative Nurick scores, postoperative Odom scores, and preoperative and postoperative Cobb angles. RESULTS The mean patient age (± SD) was 67 ± 7.7 years; 8 patients were male. The average number of disc levels operated on was 2.2 (range 1-4). The mean Nurick score was 1.6 ± 0.7 preoperatively and improved to 0.3 ± 0.7 postoperatively (p < 0.0005). The postoperative Odom scores indicated excellent outcomes for 4 patients, good for 3, fair for 2, and poor for 1. The average preoperative focal Cobb angle at the disc levels operated on was -0.43º ± 1.9º. The average Cobb angle at the last follow-up visit was 0.25° ± 1.6° (p = 0.6). The average follow-up time was 18.9 ± 32.1 months. There were no intraoperative or postoperative complications. CONCLUSIONS For selected patients with CSM, whose pathologic changes are primarily posterior and who have acceptable preoperative lordosis, MEDS is an alternative to open laminectomy and laminoplasty.

Analysis of Risk Factors and Survival in Pediatric High-Grade Spinal Cord Astrocytoma: A Population-Based Study

Background/Aims: Primary pediatric high-grade spinal cord astrocytomas are rare neoplasms with poor prognoses. Using the Surveillance, Epidemiology, and End Results (SEER) database, we analyzed prognostic factors and survival. Methods: Pediatric patients with histologically confirmed diagnoses of primary high-grade spinal cord astrocytoma (WHO grade III-IV) from 1973 to 2008 in the SEER database were studied. Univariate and multivariate Cox proportional hazards models were used to analyze the relationship between demographic, tumor grade, and treatment factors on survival. Results: Median survival in the 48 patient cohort was 10 months. Increasing age and higher tumor grade were found to be significantly associated with higher mortality. For children aged <7, 7-12, and 13-18 years, median survival was 22, 11, and 8 months, respectively. For children with anaplastic astrocytoma (WHO grade III), median survival was 12 months, compared with 7 months for those with glioblastoma multiforme (WHO grade IV). This study did not find a statistically significant relationship between sex, race, presence of radiation therapy or extent of surgical resection and mortality. Conclusion: Survival in primary pediatric high-grade spinal cord astrocytomas was positively associated with younger age and lower tumor grade. Survival was not associated with other demographic or treatment modality factors.