Outcome data and analysis in pediatric neurosurgery

Characteristics and overall survival in pediatric versus adult skull base chordoma: a population-based study

PURPOSE

Less than 5% of chordomas occur in pediatric patients. While many studies have explored the treatment and outcomes of skull base chordomas, few have focused on the differences between pediatric and adult populations. The aim of this study is to analyze the epidemiological variables and clinical outcomes between pediatric and adult skull base chordomas using a large-sample, population-based cancer database.

METHODS

The National Cancer Database was queried between 2004 and 2015 for skull base chordomas. We stratified patients as pediatric (<18 years) and adults (≥18 years). We compared several clinical covariates between the two groups.

RESULTS

Our cohort consisted of 658 patients, 61 pediatric (9.3%), and 597 adults (90.7%). Pediatric patients were more likely to have larger tumor size (41.4 ± 15.7 mm versus 34.1 ± 15.8 mm, p < 0.01) and universally treated at academic facilities. There was no significant difference in overall survival.

CONCLUSIONS

Pediatric skull base chordomas are rare tumors that are managed with aggressive surgical resection, followed by radiation. While there may be difference between tumor presentation, outcomes between pediatric and adult patients are similar.

Intraoperative Neurophysiology Monitoring for Spinal Dysraphism

Spinal dysraphism often causes neurological impairment from direct involvement of lesions or from cord tethering. The conus medullaris and lumbosacral roots are most vulnerable. Surgical intervention such as untethering surgery is indicated to minimize or prevent further neurological deficits. Because untethering surgery itself imposes risk of neural injury, intraoperative neurophysiological monitoring (IONM) is indicated to help surgeons to be guided during surgery and to improve functional outcome. Monitoring of electromyography (EMG), motor evoked potential, and bulbocavernosus reflex (BCR) is essential modalities in IONM for untethering. Sensory evoked potential can be also employed to further interpretation. In specific, free-running EMG and triggered EMG is of most utility to identify lumbosacral roots within the field of surgery and filum terminale or non-functioning cord can be also confirmed by absence of responses at higher intensity of stimulation. The sacral nervous system should be vigilantly monitored as pathophysiology of tethered cord syndrome affects the sacral function most and earliest. BCR monitoring can be readily applicable for sacral monitoring and has been shown to be useful for prediction of postoperative sacral dysfunction. Further research is guaranteed because current IONM methodology in spinal dysraphism is still deficient of quantitative and objective evaluation and fails to directly measure the sacral autonomic nervous system.

Towards Guideline-Based Management of Tethered Cord Syndrome in Spina Bifida: A Global Health Paradigm Shift in the Era of Prenatal Surgery

An estimated 60% of the world's population lives in Asia, where the incidence of neural tube defects is high. Aware that tethered cord syndrome (TCS) is an important comorbidity, the purpose of this systematic review was to explore the treatment of TCS among individuals living with spina bifida (SB) in Asia. MEDLINE and Embase databases were searched for relevant studies published from January 2000 to June 2018. Search terms such as 'spinal dysraphism,' 'spinabifida,' 'diastematomyelia,' 'lipomeningocele,' 'lypomyelomeningocele,' 'meningomyelocele,' and 'tethered cord syndrome' were used in diverse combinations. Of the 1,290 articles that were identified in accordance with PRISMA (Preferred Items for Systematic Reviews and Meta-Analyses) guidelines, 15 Asia-based studies met the inclusion criteria. Significant differences in the diagnostic criteria and management of TCS were documented. As the surgical techniques for prenatal closure of the spinal defect continue to evolve, their adoption internationally is likely to continue. In this setting, a clear and evidence-based approach to the definition and management of TCS is essential. The recent publication by the Spina Bifida Association of America of their updated care guidelines may serve as a tool used to promote a systematized approach to diagnosing and treating TCS among individuals with SB in the region, as well as globally.

Reinfection after treatment of first cerebrospinal fluid shunt infection: a prospective observational cohort study

OBJECTIVE CSF shunt infection requires both surgical and antibiotic treatment. Surgical treatment includes either total shunt removal with external ventricular drain (EVD) placement followed by new shunt insertion, or distal shunt externalization followed by new shunt insertion once the CSF is sterile. Antibiotic treatment includes the administration of intravenous antibiotics. The Hydrocephalus Clinical Research Network (HCRN) registry provides a unique opportunity to understand reinfection following treatment for CSF shunt infection. This study examines the association of surgical and antibiotic decisions in the treatment of first CSF shunt infection with reinfection. METHODS A prospective cohort study of children undergoing treatment for first CSF infection at 7 HCRN hospitals from April 2008 to December 2012 was performed. The HCRN consensus definition was used to define CSF shunt infection and reinfection. The key surgical predictor variable was surgical approach to treatment for CSF shunt infection, and the key antibiotic treatment predictor variable was intravenous antibiotic selection and duration. Cox proportional hazards models were constructed to address the time-varying nature of the characteristics associated with shunt surgeries. RESULTS Of 233 children in the HCRN registry with an initial CSF shunt infection during the study period, 38 patients (16%) developed reinfection over a median time of 44 days (interquartile range [IQR] 19-437). The majority of initial CSF shunt infections were treated with total shunt removal and EVD placement (175 patients; 75%). The median time between infection surgeries was 15 days (IQR 10-22). For the subset of 172 infections diagnosed by CSF culture, the mean ± SD duration of antibiotic treatment was 18.7 ± 12.8 days. In all Cox proportional hazards models, neither surgical approach to infection treatment nor overall intravenous antibiotic duration was independently associated with reinfection. The only treatment decision independently associated with decreased infection risk was the use of rifampin. While this finding did not achieve statistical significance, in all 5 Cox proportional hazards models both surgical approach (other than total shunt removal at initial CSF shunt infection) and nonventriculoperitoneal shunt location were consistently associated with a higher hazard of reinfection, while the use of ultrasound was consistently associated with a lower hazard of reinfection. CONCLUSIONS Neither surgical approach to treatment nor antibiotic duration was associated with reinfection risk. While these findings did not achieve statistical significance, surgical approach other than total removal at initial CSF shunt infection was consistently associated with a higher hazard of reinfection in this study and suggests the feasibility of controlling and standardizing the surgical approach (shunt removal with EVD placement). Considerably more variation and equipoise exists in the duration and selection of intravenous antibiotic treatment. Further consideration should be given to the use of rifampin in the treatment of CSF shunt infection. High-quality studies of the optimal duration of antibiotic treatment are critical to the creation of evidence-based guidelines for CSF shunt infection treatment.

Prospective review of 30-day morbidity and mortality in a paediatric neurosurgical unit

PURPOSE

The purpose of this study is to record the 30-day and inpatient morbidity and mortality in paediatric patients in a tertiary neuroscience centre over a 2-year period. The intentions were to establish the frequency of significant adverse events, review the current published rates of morbidity in paediatric neurosurgical patients and propose three clinical indicators for future comparison.

METHODS

All deaths and adverse events were prospectively recorded from 1 January 2014 to 31 December 2015. Each adverse event was categorised, allocated a clinical impact severity score and linked to a neurosurgical procedure wherever possible. Where a patient suffered several adverse events in the same admission, each event was recorded separately. If a patient had been discharged home, an adverse event was recorded if it occurred within 30 days of admission.

RESULTS

Five hundred forty-nine procedures were performed in 287 patients (aged <16 years). One hundred thirty significant adverse events were identified. The following are the three clinical indicators: significant adverse event rate: 111 (20.2%) operations were linked to at least one significant adverse event; unscheduled return to theatre rate: 81 (14.8%) operations were associated with an adverse event that resulted in an unscheduled return to theatre; and surgical site infection rate: 29 (5.3%) operations were associated with an infection.

CONCLUSION

Complications and adverse events are common in paediatric neurosurgery. Prospective, continuous surveillance will promote both quality assurance and quality improvement in the neurosurgical care delivered to patients.

Variability in Management of First Cerebrospinal Fluid Shunt Infection: A Prospective Multi-Institutional Observational Cohort Study

OBJECTIVES

To describe the variation in approaches to surgical and antibiotic treatment for first cerebrospinal fluid (CSF) shunt infection and adherence to Infectious Diseases Society of America (IDSA) guidelines.

STUDY DESIGN

We conducted a prospective cohort study of children undergoing treatment for first CSF infection at 7 Hydrocephalus Clinical Research Network hospitals from April 2008 through December 2012. Univariate analyses were performed to describe the study population.

RESULTS

A total of 151 children underwent treatment for first CSF shunt-related infection. Most children had undergone initial CSF shunt placement before the age of 6 months (n =  98, 65%). Median time to infection after shunt surgery was 28 days (IQR 15-52 days). Surgical management was most often shunt removal with interim external ventricular drain placement, followed by new shunt insertion (n = 122, 81%). Median time from first negative CSF culture to final surgical procedure was 14 days (IQR 10-21 days). Median duration of intravenous (IV) antibiotic use duration was 19 days (IQR 12-28 days). For 84 infections addressed by IDSA guidelines, 7 (8%) met guidelines and 61 (73%) had longer duration of IV antibiotic use than recommended.

CONCLUSIONS

Surgical treatment for infection frequently adheres to IDSA guidelines of shunt removal with external ventricular drain placement followed by new shunt insertion. However, duration of IV antibiotic use in CSF shunt infection treatment was consistently longer than recommended by the 2004 IDSA guidelines.

The Impact of Endoscopic Third Ventriculostomy on Shunt Revision Rate: A 14-Year Experience at a Single Institution

BACKGROUND

Shunt-related procedures in the treatment of hydrocephalus are often associated with malfunction and revision resulting in significant patient morbidity and financial impact on the health care system. The increased utilization of endoscopic third ventriculostomy (ETV) as an alternative treatment paradigm for obstructive hydrocephalus carries the theoretical expectation of concomitant decreased numbers of shunt procedures. The objective of the present study was to determine the impact of ETV on shunt-related procedures within a 14-year interval (1998-2011), during which ETV has gained wider acceptance and greater utilization.

METHODS

This retrospective chart review describes the annual rate of pediatric patients who underwent either ETV or shunt-related procedures at New York Presbyterian Hospital Weill-Cornell Medical Center. Statistical analyses were done to analyze possible correlation between relative rates of these cases.

RESULTS

During the 14-year study period, 954 procedures were performed for the treatment of hydrocephalus (159 ETVs and 795 shunt-related procedures). Of the shunts, 356 were initial insertions and 439 were revisions. The number of ETVs increased from 8 procedures in 1998/1999 to 34 in 2010/2011, whereas the total number of annual shunt-related procedures decreased from 146 to 99. The relative ratios of ETVs and shunt-related procedures to the total number of cases demonstrate an inverse relationship over time (Spearman correlation coefficient rs = -1.0; P = 0.0004).

CONCLUSIONS

Based on prior cost-effectiveness analyses, the observed trend of the inverse correlation between ETVs and shunt-related procedures may contribute to financial savings and improvement in patient outcomes. Further study is required to define the impact on morbidity and associated success rates.

Does size matter? Minimally invasive approach in pediatric neurosurgery--a review of 125 minimally invasive surgeries in children: clinical history and operative results

OBJECTIVE

Surgery is an integral component and typically the first line of therapy for children with central nervous system tumors. Conventional aims of neurosurgery including tumor removal, management of hydrocephalus, and diagnostic sampling have been radically modified with innovative technologies such as navigational guidance, functional mapping, endoscopic surgery, second-look surgery, and physiologic imaging. The aim of the study was to investigate our operative results using minimally invasive technique in children.

METHODS

Clinical features, surgical technique and results, length of hospital stay, and complications were reviewed retrospectively. Pre- and early postoperative MRI was evaluated for degree of surgical resection. Correlation of tumor localization, lengths of hospital stay as well as surgical techniques and clinical outcome with follow-up was investigated.

RESULTS

One hundred ten patients underwent 125 tumor resections using minimally invasive approaches (image- and functional guided tailored keyhole approaches for supratentorial, retrosigmoidal, and suboccipital keyhole approaches for infratentorial lesions). Most tumors were located supratentorial (62.4 %). In 29.6 % of the cases, the surgery was performed endoscope-assisted or endoscope-controlled; neuronavigation was used in 45.6 % and ultrasound in 24 % of the cases. Astrocytomas were diagnosed in 26.4 % of cases, ependymomas in 9.6 %, and medulloblastomas in 14.4 %. Gross total resection was achieved in 60.8 %. The most common complication was CSF fistula (n = 9), and the occurrence was significantly higher in younger children (p = 0.0001) and infratentorial located tumors (p = 0.02). Surgery for posterior fossa lesions was associated with a longer hospital stay (p = 0.02) compared to surgery of supratentorial lesions. Mean follow-up was 29.7 months (range 0.3-79.1 months), and most of the children recovered during the further course of the follow-up (symptoms better or idem in 74.4 %).

CONCLUSION

In conclusion, our study shows that it is possible to achieve surgical results in the pediatric population applying minimal invasive techniques comparable to those described in the literature.

Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances in adolescence: a nationwide cohort study

BACKGROUND

Few human cohort studies on anesthesia-related neurotoxicity and the developing brain have focused on and compared specific surgeries and conditions. These studies cannot disentangle the effects of anesthesia from those of the surgery and underlying conditions. This study aimed at assessing the impact of specific neurosurgical conditions and procedures in infancy on mortality and academic achievements in adolescence.

METHODS

A nationwide unselected register-based follow-up study of the Danish birth cohorts 1986-1990 compared academic performances of all children having undergone neurosurgeries as infants with a randomly selected, age-matched 5% sample of the same cohorts. The two groups were compared regarding mortality prior to June 1st, 2006, average test scores at ninth grade, and finally the proportion of children not attaining test scores.

RESULTS

The exposure group comprised 228 and the control group 14 698 individuals. Hydrocephalus (n = 130), craniotomy (n = 43), and myelomeningocele/encephalocele children (n = 55) had a higher mortality (18.5.0%, 18.6%, and 7.3%, respectively) vs controls (1.3%; P < 0.00001, P < 0.00001, and P = 0.0052, respectively). Average test scores were significantly lower than controls in hydrocephalus and craniotomy (P = 0.0043 and P = 0.0077) but not myelomeningocele/encephalocele children (P = 0.2785); the proportion of available test scores were significantly lower in all three groups (40.8%, 60.0%, and 67.3%, respectively) vs 86.8% in controls (P < 0.00001, P = 0.000077, and P = 0.000064).

CONCLUSION

Neurosurgery in infancy was associated with high mortality and significantly impaired academic achievements in adolescence. When studying anesthesia-related neurotoxicity and the developing brain, focus on specific surgeries/conditions is important. Pooling of major/minor conditions and major/minor surgeries should be avoided.

Improvement in intraoperative transcranial electrical motor-evoked potentials in tethered cord surgery: an analysis of 45 cases

BACKGROUND

Improvement of transcranial electrical motor-evoked potentials (TeMEPs) following untethering during tethered cord surgery (TCS) and its clinical significance have not been analyzed in the literature.

METHODS

Forty-five consecutive cases of tethered cord were operated on with multimodality intraoperative neurophysiological monitoring (IONM) between February 2005 and January 2012. Intraoperative TeMEP change was classified as improvement, worsening or no change. Motor, sensory, bladder and bowel symptoms and signs were evaluated preoperatively, in the first week post-surgery and at the last follow-up (maximum of 2 years).

RESULTS

Patient age ranged from 5 to 44 years (mean, 16 ± 10 years), with 30 children. Intraoperative MEPs improved in 23 (51 %), remained the same in 21 (46.7 %) and worsened in 1 (2 %) patient. Motor improvement occurred in 7 patients and clinical improvement in 17 patients in the immediate postoperative period. Postoperative neurological worsening occurred in one patient (2.2 %). Improved and stable MEPs correlated with the motor (p = 0.002) and clinical improvement (p = 0.02) in the immediate postoperative period. Follow-up was available in 35 patients (77.7 %), ranging from 5 to 24 months (median, 21 months; mean, 17.7 ± 6.8 months). There was late clinical improvement in 73.5 % of the patients in whom the intraoperative MEP had remained the same or improved. However, there was no statistically significant correlation between MEP change and long-term outcome.

CONCLUSIONS

Intraoperative MEP improvement occurs in about 50 % of the patients following successful untethering. This finding probably provides support to the ischemic theory of tethered cord syndrome.

Recurrent tethered cord: radiological investigation and management

INTRODUCTION

Recurrent tethered cord (RTC) is almost the rule after the repair of myelomeningocele and quite frequent after the repair of lipomyelomeningocele, resulting from the adhesions of the placode within a too narrow spinal canal. About one-third of patients with myelomeningocele and 10 % of those with spinal lipoma develop symptomatic RTC, mainly caused by the ischemic-metabolic injuries due to the cord stretching. The goal of this review is to provide information about the pathophysiology, the radiological picture, and the management of RTV according to the pertinent literature and the authors' experience.

RADIOLOGICAL INVESTIGATION

The magnetic resonance imaging (MRI) picture is characterized by a low position of the conus and by tethering of the spinal cord to the subcutaneous scar or to the inner surface of the spinal canal. The radiological work-up always includes brain MRI, to rule out other possible causes of late neurological deterioration (as shunt malfunction), and MRI of the whole spinal cord, to detect possible associated lesions (syringomyelia, dermoids, etc.). X-rays and/or computed tomography scan of the spine is required for the assessment of scoliosis or other bony malformations.

MANAGEMENT

The surgical treatment is planned after a multidisciplinary neurological, urological, orthopedic, physiatric, and radiological evaluation. The surgical detethering is carried out cautiously, possibly with electrophysiological intraoperative monitoring. Surgery ensures improvement or stability of the clinical picture in 70-80 % of cases, the remaining 20-30 % of patients needing multiple operations for their recovery. Complications may affect up to one-third of operated patients, being mainly represented by CSF leak, pseudomeningocele, and shunt malfunction.

United Kingdom 30-day mortality rates after surgery for pediatric central nervous system tumors

OBJECT

In an increasing culture of medical accountability, 30-day operative mortality rates remain one of the most objective measurements reported for the surgical field. The authors report population-based 30-day postoperative mortality rates among children who had undergone CNS tumor surgery in the United Kingdom.

METHODS

To determine overall 30-day operative mortality rates, the authors analyzed the National Registry of Childhood Tumors for CNS tumors for the period 2004-2007. The operative mortality rate for each tumor category was derived. In addition, comparison was made with the 30-day operative mortality rates after CNS tumor surgery reported in the contemporary literature. Finally, by use of a funnel plot, institutional performance for 30-day operative mortality was compared for all units across the United Kingdom.

RESULTS

The overall 30-day operative mortality rate for children undergoing CNS tumor surgery in the United Kingdom during the study period was 2.7%. When only malignant CNS tumors were analyzed, the rate increased to 3.5%. One third of the deaths occurred after discharge from the hospital in which the surgery had been performed. The highest 30-day operative mortality rate (19%) was for patients with choroid plexus carcinomas. A total of 20 institutions performed CNS tumor surgery during the study period. Rates for all institutions fell within 2 SDs. No trend associating operative mortality rates and institutional volume was found. In comparison, review of the contemporary literature suggests that the postoperative mortality rate should be approximately 1%.

CONCLUSIONS

The authors believe this to be the first report of national 30-day surgical mortality rates specifically for children with CNS tumors. The study raises questions about the 30-day mortality rate among children undergoing surgery for CNS tumors. International consensus should be reached on a minimum data set for outcomes and should include 30-day operative mortality rates.

A comprehensive analysis of early outcomes and complication rates after 769 craniotomies in pediatric patients

PURPOSE

Perioperative complications following craniotomy in pediatric neurosurgery have received little attention. We analyzed perioperative complications and early outcomes following craniotomy in a large cohort of pediatric patients.

METHODS

A retrospective chart review identified 769 operations (27 % epilepsy surgery, 26 % trauma, 21 % tumor, 7 % vascular, 4 % infections, 14 % other, and 88 % supratentorial) in 641 patients <16 years (mean age 8.5 years). We recorded all perioperative complications and functional outcomes 30 days after surgery.

RESULTS

Excluding epilepsy surgery cases, 17.5 % patients had emergency surgery. There were 38 new major neurological deficits (5.0 %; excluding deficits incurred as part of the surgical strategy). New neurological deficits occurred more frequently following operations for brain tumors, when compared to other surgeries (P < 0.001), and after surgery for infratentorial lesions (P < 0.001). Local complications occurred in 3.9 %, systemic complications in 2.5 % of patients. Ventricular shunting or endoscopic ventriculostomy was necessary in 87 patients (11.3 %). Surgical mortality was 2.0 % (including moribund patients after trauma or vascular incidence). Preoperative Karnofsky Performance Index (KPI) and the incurrence of new neurological deficits proved the most powerful predictors of functional outcome. Emergency surgery or repeat craniotomies were not correlated with increased rates of local complications.

CONCLUSIONS

Craniotomies for pediatric patients carry a low morbidity and mortality. Systemic complications seem to occur less often in the pediatric than in the adult population. Good surgical outcomes require a proper balance between local pediatric neurosurgical care for emergency cases and centralized treatment of more difficult cases.

Feasibility of repeat surgery for pediatric brain tumors: an objective assessment of perioperative outcomes

OBJECT

Repeat surgery for pediatric brain tumors is gaining acceptance, with extent of resection an important predictor of outcome. However, repeat surgeries may be associated with increased morbidity. Few studies in the literature provide such outcomes objectively. The authors report on their experience with repeat surgery at a tertiary care neurooncology referral center in India.

METHODS

A prospectively maintained database documented epidemiological, clinical, radiological, operative, and perioperative events. The authors analyzed 117 children (younger than 18 years of age) who had undergone various resective surgeries for brain tumors over a period of 5 years. Assessed end points included immediate postoperative neurological status, neurological outcome at discharge, regional complications, systemic complications, overall morbidity, and mortality.

RESULTS

The majority of children (48%) were between 3 and 10 years of age. Elevated intracranial pressure (70% of patients) and neurological deficits (60% of patients) were the commonest presenting symptoms. A significant proportion of patients (35%) had a poor Karnofsky Performance Scale score (≤ 70). Supratentorial procedures were performed in 58% of the patients. Most patients (72%) had large (> 4 cm) tumors. Fifty-eight patients (50%) had received prior treatment, surgery in 55. Neurological morbidity (worsening), regional complications, and systemic complications occurred in 27%, 32%, and 25% of patients overall, respectively. Overall morbidity was 44.4% (26.5% major), and perioperative mortality was 7.7%. Neurological worsening occurred more frequently in patients undergoing a first surgery (p = 0.038), whereas wound-related complications were more common in those undergoing reoperations (p = 0.00).

CONCLUSIONS

Pediatric patients had larger tumors and were more likely to present with a poor performance status, often after prior treatment, than their adult counterparts. Wound-related complications were higher in the previously treated subgroup; however, neurological complications were fewer, probably because of a favorable selection of patients. Despite the unavailability of advanced intraoperative aids, acceptable levels of overall morbidity and mortality could be achieved in repeat surgeries for pediatric brain tumors.

Pediatric hydrocephalus outcomes: a review

The outcome of pediatric hydrocephalus, including surgical complications, neurological sequelae and academic achievement, has been the matter of many studies. However, much uncertainty remains, regarding the very long-term and social outcome, and the determinants of complications and clinical outcome. In this paper, we review the different facets of outcome, including surgical outcome (shunt failure, infection and independence, and complications of endoscopy), clinical outcome (neurological, sensory, cognitive sequels, epilepsy), schooling and social integration. We then provide a brief review of the English-language literature and highlighting selected studies that provide information on the outcome and sequelae of pediatric hydrocephalus, and the impact of predictive variables on outcome. Mortality caused by hydrocephalus and its treatments is between 0 and 3%, depending on the duration of follow-up. Shunt event-free survival (EFS) is about 70% at one year and 40% at ten years. The EFS after endoscopic third ventriculostomy (ETV) appears better but likely benefits from selection bias and long-term figures are not available. Shunt infection affects between 5 and 8% of surgeries, and 15 to 30% of patients according to the duration of follow-up. Shunt independence can be achieved in 3 to 9% of patients, but the definition of this varies. Broad variations in the prevalence of cognitive sequelae, affecting 12 to 50% of children, and difficulties at school, affecting between 20 and 60%, attest of disparities among studies in their clinical evaluation. Epilepsy, affecting 6 to 30% of patients, has a serious impact on outcome. In adulthood, social integration is poor in a substantial number of patients but data are sparse. Few controlled prospective studies exist regarding hydrocephalus outcomes; in their absence, largely retrospective studies must be used to evaluate the long-term consequences of hydrocephalus and its treatments. This review aims to help to establish the current state of knowledge and to identify conflicting data and unanswered questions, in order to direct future studies.

Unplanned reoperation rates in pediatric neurosurgery: a single center experience and proposed use as a quality indicator

OBJECT

The pediatric neurosurgery practice over 2 years was reviewed at a tertiary neurosciences center. The intention was to establish the frequency of unplanned reoperations at the center, investigate the factors responsible, and consider using unplanned reoperations as a quality indicator.

METHODS

All pediatric neurosurgical operations done between January 2008 and January 2010 were reviewed using data from operation theater logs and hospital records. Data were recorded as per the standard requirements of the Society of British Neurological Surgeons for incorporation into the national database. "Unplanned reoperation" was defined as any unscheduled secondary procedure required for a complication resulting directly or indirectly from the index operation or as an unscheduled return to the operating theater for the same condition. Operations were defined as "urgent" if they had to be performed out of hours (that is, outside the hours of 8:00 a.m. to 5:00 p.m.), "emergency elective" if they were included on the emergency list but within working hours, and "routine elective" if they were on the scheduled operations list. Both overall and 30-day unplanned reoperation rates were considered. Factors influencing unplanned reoperations were explored using a logistic regression model.

RESULTS

Four hundred ten operations were analyzed. The overall unplanned reoperation rate was 28%. The median time to an unplanned reoperation was 9 days. Risk factors for unplanned reoperations included a CSF diversion procedure (OR 7, p < 0.0001) and an urgent procedure (OR 2.5, p = 0.02, higher unplanned reoperations for urgent procedures relative to routine electives). The 30-day unplanned reoperation rate was 17%. Urgent cases composed 32% of all operations. Trainees performed 52% of the urgent operations. Forty-four percent of all operations were related to CSF diversion. Sixty-four percent of patients had reoperations during the course of the study period, and 44% of these reoperations were unplanned.

CONCLUSIONS

An unplanned return to the operation theater is common in the authors' pediatric neurosurgical practice and is procedure specific. Unplanned reoperation rates may be useful for monitoring quality across hospitals and identifying opportunities for quality improvement. The authors propose the use of this index as a quality indicator and advocate its validation in a prospective multicenter study.

Association of intraventricular hemorrhage secondary to prematurity with cerebrospinal fluid shunt surgery in the first year following initial shunt placement

OBJECT

The neurosurgical literature has conflicting findings regarding the association between indications for CSF shunt placement and subsequent shunt surgery. The object of this study was to identify baseline factors at the time of initial CSF shunt placement that are independently associated with subsequent surgery.

METHODS

This was a retrospective cohort study of children ages 0-18 years who underwent initial CSF shunt placement between January 1, 1997, and October 12, 2006, at a tertiary care children's hospital. The outcome of interest was CSF shunt surgery (either for revision or infection) within 12 months after initial placement. Associations between subsequent CSF shunt surgery and indication for the initial shunt, adjusting for patient age and surgeon factors at the time of initial placement, were estimated using multivariate logistic regression. Medical and surgical decisions, which varied according to surgeon, were examined separately in a univariate analysis.

RESULTS

Of the 554 children in the study cohort, 233 (42%) underwent subsequent CSF shunt surgery, either for revision (167 patients [30%]) or infection (66 patients [12%]). In multivariate logistic regression modeling, significant risk factors for subsequent CSF shunt surgery included (compared with aqueductal stenosis) intraventricular hemorrhage (IVH) secondary to prematurity (adjusted odds ratio [AOR] 2.2, 95% CI 1.1-4.5) and other unusual indications (AOR 3.7, 95% CI 1.0-13.6). The patient's age at initial CSF shunt placement was not significantly associated with increased odds of subsequent surgery after adjusting for other associated factors.

CONCLUSIONS

The occurrence of IVH is associated with increased odds of subsequent CSF shunt surgery within 12 months after shunt placement. Families of and care providers for children with IVH should be attuned to their increased risk of shunt failure.

Surgical morbidity and mortality of pediatric brain tumors: a single center audit

OBJECTIVES

The primary aim of this study is to perform an internal quality control of pediatric brain tumor surgery in the neurosurgical department of the VU University Medical Center Amsterdam (The Netherlands). Secondly, this study aims to contribute to the accumulating data concerning outcome in pediatric neurosurgery, in order to establish institutional practice benchmarks.

METHODS

We report the surgical mortality and morbidity of 121 patients (0-18 years) surgically treated for a brain tumor from January 1999 to August 2007. Patients, in whom only a brain tumor biopsy was performed, were excluded.

RESULTS

Mean age at first surgery was 8.2 years. Of the 121 patients, 14 had a second surgery, and two underwent a third surgery (for a total of 137 operations). Of all 121 primary surgeries, 66% were total resections, 26% subtotal resections, and 8% partial resections. The overall surgical morbidity rate in this study was 69% after first surgery, 50% after second surgery, and one out of two after third surgery.

CONCLUSION

These overall morbidity rates are comparable to other published mixed case series. The surgical mortality rate was 0.8%; this is comparable to the lowest rates reported for high-volume neurosurgical centers. We encourage other neurosurgical centers to collect, analyze, and publish their data. These data can then serve as a basis for comparison with other pediatric neurosurgical centers and will eventually lead to an improvement of pediatric neurosurgical practice and patient care.

Infection rates following initial cerebrospinal fluid shunt placement across pediatric hospitals in the United States. Clinical article

OBJECT

Reported rates of CSF shunt infection vary widely across studies. The study objective was to determine the CSF shunt infection rates after initial shunt placement at multiple US pediatric hospitals. The authors hypothesized that infection rates between hospitals would vary widely even after adjustment for patient, hospital, and surgeon factors.

METHODS

This retrospective cohort study included children 0-18 years of age with uncomplicated initial CSF shunt placement performed between January 1, 2001, and December 31, 2005, and recorded in the Pediatric Health Information System (PHIS) longitudinal administrative database from 41 children's hospitals. For each child with 24 months of follow-up, subsequent CSF shunt infections and procedures were determined.

RESULTS

The PHIS database included 7071 children with uncomplicated initial CSF shunt placement during this time period. During the 24 months of follow-up, these patients had a total of 825 shunt infections and 4434 subsequent shunt procedures. Overall unadjusted 24-month CSF shunt infection rates were 11.7% per patient and 7.2% per procedure. Unadjusted 24-month cumulative incidence rates for each hospital ranged from 4.1 to 20.5% per patient and 2.5-12.3% per procedure. Factors significantly associated with infection (p < 0.05) included young age, female sex, African-American race, public insurance, etiology of intraventricular hemorrhage, respiratory complex chronic condition, subsequent revision procedures, hospital volume, and surgeon case volume. Malignant lesions and trauma as etiologies were protective. Infection rates for each hospital adjusted for these factors decreased to 8.8-12.8% per patient and 1.4-5.3% per procedure.

CONCLUSIONS

Infections developed in > 11% of children who underwent uncomplicated initial CSF shunt placements within 24 months. Patient, hospital, and surgeon factors contributed somewhat to the wide variation in CSF shunt infection rates across hospitals. Additional factors may contribute to variation in CSF shunt infection rates between centers, but further study is needed. Benchmarking and future prospective multicenter studies of CSF shunt infection will need to incorporate these and other patient, hospital, and surgeon factors.

Myelomeningocele: long-term neurosurgical treatment and follow-up in 202 patients

OBJECT

In this paper the authors focus on the long-term management of myelomeningocele (MMC) and its associated conditions.

METHODS

During a 25-year period, 220 consecutive patients with MMC underwent surgical repair. There were 203 cases (92%) of enlarged ventricles, but only 171 cases (78%) of hydrocephalus. Seven infants (3%) presented with early brainstem dysfunction; two improved after ventricular drainage, whereas five required craniocervical decompression.

RESULTS

Overall, five neonates (2%) died; 215 patients (98%) were eventually discharged from the hospital and of these, 202 (94%) remained in the authors' outpatient program. During the follow-up (range 1-25 years, mean 9.3 years), 96 patients required shunt revision (63% of shunts); 16 patients (8%) experienced late brainstem dysfunction that was treated by shunt placement in eight and by craniocervical decompression in the other eight; 137 patients (68%) harbored hydrosyringomyelia, but only six required surgical treatment; 40 patients (20%) presented symptoms of tethered cord, but surgical detethering was indicated in just 22 patients (11%). There were five deaths (2%), and severe adjunctive neurological morbidity was reported in 18 patients (9%) (owing to various causes). "Social" results have been evaluated by extrapolating 38 patients older than 15 years of age whose initial lesions were below L-2: 37 (97%) of these patients were fully independent, had "social urinary continence," and attended normal schools.

CONCLUSIONS

Currently, many patients with MMC reach adulthood and social continence; self-care may be expected in a large percentage of cases. Nevertheless, there are many associated neurological conditions that have to be faced, and a coordinated network of care remains necessary throughout the patient's life. Moreover, these patients often present with so many peculiarities that indications for treatment, choice of proper techniques, and results are not always clear and evident.

A mathematical model of survival in a newly inserted ventricular shunt

OBJECT

The object of this study was to mathematically model the prognosis of a newly inserted shunt in pediatric or adult patients with hydrocephalus.

METHODS

A structured search was performed of the English-language literature for case series reporting shunt failure, patient mortality, and shunt removal rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to predict the outcome of a shunt after insertion. Separate models were used to predict shunt survival rates for children (patients < 17 years old) and adults.

RESULTS

Shunt survival rates in children and adults were calculated for 1 year (64.2 and 80.1%, respectively), 5 years (49.4 and 60.2%, respectively), and the median (4.9 and 7.3 years, respectively). The longer-term rates predicted by the model agree closely with those reported in the literature.

CONCLUSIONS

This model gives a comprehensive view of the fate of a shunt for hydrocephalus after insertion. The advantages of this model compared with Kaplan-Meier survival curves are discussed. The model used in this study may provide useful prognostic information and aid in the early evaluation of new shunt designs and techniques.

Have we made progress in preventing shunt failure? A critical analysis

OBJECT

The goal of this study was to determine whether failure rates of hydrocephalus shunts have fallen over the years as a result of experience or technical improvements.

METHODS

A structured search was performed of the English language literature for case series reporting failure rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to analyze failure rates statistically for temporal trends. Separate models were used for children (< 17 years old) and adults.

RESULTS

In children, the shunt failure rate was 31.3% for the 1st year and 4.5% per year thereafter. There were no significant changes in either rate over time. Although 1st-year failure rates in adults have fallen slightly over time, late failure rates have risen.

CONCLUSIONS

Progress in preventing shunt failures has not been made over the last several decades. Any improvements made in shunt materials or insertion techniques have been overshadowed by biological and other factors.

Tethered cord syndrome: nationwide inpatient complications and outcomes

Object

Previous investigations of health outcome after spinal surgery for tethered cord syndrome (TCS) have been single-institution studies. The aim of this study was to report inpatient complications and outcomes on a nationwide level.

Methods

The Nationwide Inpatient Sample (NIS) was used to identify patients who underwent spinal surgery for TCS in the US between 1993 and 2002. Patients who had a primary diagnosis of TCS (ICD-9 742.59) and also underwent spinal laminectomies were included in this study. Multivariate analysis was performed to analyze the effects of patient and hospital characteristics on variables such as mortality rate, nonfatal complications, LOS, and adverse outcomes in general (defined as death or discharge to an institution rather than home).

Results

The NIS sample included data on 9733 patients with TCS who underwent surgery. The means for mortality rate, complication rate, and LOS, respectively, were 0.0005%, 9.48%, and 5.6 days. Postoperative hemorrhages or hematomas (mean rate 2.3%) were the most common complications reported. Age and complications were the only significant predictors of adverse outcome on multivariate analysis. Patients older than 65 years had a threefold increase in risk of adverse outcome compared with patients 18 to 44 years of age. On average, one postoperative complication led to a 3-day increase in mean LOS and added more than $9000 to hospital charges.

Conclusions

This study provides a national perspective on inpatient complications and outcomes after spinal surgery for TCS in the United States. The authors have demonstrated the impact of age, complications, and medical comorbidities on the outcome of surgery for patients with this common disorder.

Shunt infection: is there a near-miss scenario?

OBJECT

The aim of this study was to establish whether microbiological contamination at the time of shunt insertion can be detected and used to predict the likelihood of subsequent shunt infection.

METHODS

A prospective study of pediatric patients undergoing primary shunt insertion was undertaken. Following the protocol devised for this study, three swab samples were collected from the surgical wounds during each procedure. These samples were incubated and subcultured, and the isolates were identified and stored. In patients who subsequently presented with clinical evidence of shunt infection, cerebrospinal fluid (CSF) was analyzed using microscopy, tissue cultures, and sensitivity testing. The organisms isolated at the time of shunt insertion and those responsible for subsequent shunt infection were then compared. The study population consisted of 107 pediatric patients. Because one patient underwent placement of an additional contralateral shunt system, there were 108 total shunt insertions yielding 325 swab samples. Organisms were identified in cultures of 50 swab samples (15%) obtained in 40 patients (37%). In seven of these 40 patients (17.5%) a CSF infection subsequently developed. In only one patient was the infectious organism the same as that isolated from the swab specimens. In an additional six patients (8.8%) a CSF infection occurred despite the lack of growth in the cultures from intraoperative swab samples.

CONCLUSIONS

The organisms responsible for shunt infection were rarely detected in the operative wound at the time of shunt insertion, leading the authors to conclude that the vulnerable period for bacterial colonization of shunts may not be restricted to the operative procedure as is commonly believed, but may extend throughout the postoperative period of wound healing. These findings have implications not only for a better understanding of the cause of shunt infections but also for the development of strategies to prevent them.

Multimodality intraoperative neurophysiologic monitoring findings during surgery for adult tethered cord syndrome: analysis of a series of 44 patients with long-term follow-up

STUDY DESIGN

Prospective analysis of a consecutive series in which multimodality intraoperative neurophysiologic monitoring was used as an adjunct to microneurosurgery for adult tethered cord syndrome. The results of multimodality intraoperative neurophysiologic monitoring were compared with the "gold standard" (neurologic outcomes).

OBJECTIVE

To assess the sensitivity, specificity, and positive and negative predictive values of multimodality intraoperative neurophysiologic monitoring in surgery for adult tethered cord syndrome.

SUMMARY OF BACKGROUND DATA

Although intraoperative electrophysiologic techniques may help to minimize neural injury during spinal microneurosurgery, to our knowledge, no study has quantitatively evaluated the value of multimodality intraoperative neurophysiologic monitoring in the management of adult tethered cord syndrome.

METHODS

Multimodality intraoperative neurophysiologic monitoring included posterior tibial nerve somatosensory evoked potentials (SSEPs), continuous electromyographic (EMG) monitoring of the L2 to S4 myotomes, and evoked EMG. Follow-up neurologic evaluations were performed for at least 1 year.

RESULTS

A total of 44 consecutive patients, including 19 males and 25 females (aged 43 +/- 15 years), who underwent microsurgery for adult tethered cord syndrome were evaluated. After surgery, new neurologic deficits, including 1 transient and 1 permanent, developed in 2 patients. There was 1 patient who had persistent posterior tibial nerve SSEP amplitude reduction following microsurgical manipulation. In 1 patient, a transient posterior tibial nerve SSEP amplitude reduction prompted a change in microneurosurgical strategy. This patient awoke with no new postoperative neurologic deficits. For SSEPs, the sensitivity was 50% and specificity 100%. EMG bursts were recorded in 36 patients (82%). The 2 patients with postoperative neurologic worsening had EMG activity in the myotomes, where their new deficits presented. Continuous EMG had a sensitivity of 100% and a specificity of 19%.

CONCLUSIONS

To our knowledge, this is the largest series to date reporting the use of multimodality intraoperative neurophysiologic monitoring in the surgical management of adult tethered cord syndrome. Posterior tibial nerve SSEPs have high specificity, but low sensitivity, for predicting new neurologic deficits. In contrast, continuous EMG showed high sensitivity and low specificity. Evoked EMG accurately identified functional neural tissue. The combined recording of SSEPs in concert with continuous and evoked EMGs may provide a useful adjunct to complex microsurgery for adult tethered cord syndrome.

Multi-modality neurophysiological monitoring during surgery for adult tethered cord syndrome

During complex microneurosurgery performed in patients with tethered cord syndrome, the conus medullaris and the roots that innervate the lower limbs, bladder and bowel are potentially exposed to damage. The aim of multimodality intraoperative monitoring (IOM) is to reduce the risk of inadvertent injury of neural tissue. We simultaneously record tibial nerve somatosensory evoked potentials (SSEPs) from the scalp and free run electromyography (EMG) of limb muscles supplied by L2 to S2 roots, anal and urethral sphincters. We also identify critical neural structures in the operative field, including the conus and exiting nerve roots, with a nerve stimulator to evoke EMG. SSEPs assess the sensory pathways mainly mediated by the S1 roots. Continuous EMG provides the surgeon with immediate auditory feedback resulting from irritative discharges triggered by manipulation of nerve fibres. Microstimulation can distinguish the filum terminale, scar tissue and invasive tumors from functional neural tissue, thus minimizing the risk of iatrogenic injury. Overall multimodality IOM proves a valuable adjunct to microneurosurgery of the lumbosacral spine.

Neurophysiological monitoring for safe surgical tethered cord syndrome release in adults

BACKGROUND

Release of tethered spinal cord by sectioning of the filum terminale carries a significant risk of injury to the neighboring motor and sensory nerve roots. Intraoperative neurophysiological monitoring techniques can help to minimize these adverse neurologic outcomes.

METHODS

We performed a retrospective review of 67 consecutive patients undergoing tethered cord release. We excluded 52 pediatric patients which limited our study to 15 adult patients treated during a four year period, including patients with a thick filum, low lying conus, myelomeningocele, filum tumor, spinal cord malformation, and/or lipoma. Clinical outcomes were determined from postoperative follow-up visits. Two patients were lost to follow up and were excluded from the clinical outcome analysis. Electrical stimulation of the filum terminale and lumbo-sacral nerve roots in conjunction with electromyogram (EMG) recording was performed intraoperatively.

RESULTS

The mean electrical threshold for EMG response during stimulation of the filum terminale was 37.1 volts (V), range 15 to 100 V. In comparison, the lowest threshold obtained by direct stimulation of the ventral nerve roots was a mean of 1.46 V, with a range of 0.1 to 7 V. More than 70% of the patients studied demonstrated a filum to motor root threshold ratio of 100:1 or greater. No patient developed new neurologic symptoms or signs postoperatively. Bowel and bladder function improved in 46% of patients, back pain in 39% and motor function in 31%. Eight percent reported decline in bladder control and worsening back pain postoperatively.

CONCLUSIONS

The often dramatic difference in the threshold of the filum terminale and adjacent motor nerve roots (100:1) helps to identify, isolate, and safely section the filum terminale. Tethered cord release using intraoperative neurophysiological monitoring is safe and in the majority of cases leads to improvement or at least, stabilization of neurologic function. Monitoring prevented intraoperative nerve root injury that might have resulted in immediate onset of new neurologic deficits caused by the surgical procedure.

Pathophysiology of tethered cord syndrome: correlation with symptomatology

Tethered cord syndrome (TCS) is a stretch-induced functional disorder of the spinal cord. The mechanical cause of TCS is an inelastic structure anchoring the caudal end of the spinal cord that prevents cephalad movement of the lumbosacral cord. Stretching of the spinal cord occurs in patients either when the spinal column grows faster than the spinal cord or when the spinal cord undergoes forcible flexion and extension. Research in patients and experimental animals suggests that there is a link between the clinical dysfunctions that characterize TCS and putative pathophysiological changes that accompany this syndrome. Among these changes are depression of electrophysiological activity and shifts in the reduction/oxidation ratio of cytochrome oxidase. The latter suggests that there is impairment of oxidative metabolism. These putative pathophysiological changes in TCS occur mainly within the lumbosacral cord under excessive tension. The authors discuss the pathophysiology of TCS and examine related symptoms.

Tethered spinal cord following repair of myelomeningocele

Object

The goal of this paper is to elucidate the clinical presentation of tethered cord syndrome (TCS) following repair of a myelomeningocele.

Methods

Approximately 10 to 30% of children will develop TCS following repair of a myelomeningocele. Because essentially all children with repaired myelomeningocele will have a tethered spinal cord, as demonstrated on MR imaging, the diagnosis of TCS is made based on clinical criteria. The six common clinical presentations of TCS are increased weakness (55%), worsening gait (54%), scoliosis (51%), pain (32%), orthopedic deformity (11%), and urological dysfunction (6%). The primary goal of surgery is to detach the spinal cord where it is adherent to the thecal sac, relieving the stretch on the terminal portion of the cord.

Conclusions

Early diagnosis and surgical release of the tethered cord results in stabilization or improvement in most cases. Because TCS may present with orthopedic and/or urological signs or symptoms, children with myelomeningocele should by followed, ideally in a multidisciplinary clinic, by neurosurgeons, orthopedic surgeons, and urologists who are aware of this condition.

Critical care of intracerebral and subarachnoid hemorrhage

The acute management of primary intracerebral or aneurysmal subarachnoid hemorrhage requires a comprehensive approach involving stabilization of the patient, surgical intervention, and continued intensive care treatment of medical and neurologic complications. The are several causes of intracerebral hemorrhage (ICH), including hypertension, cerebral amyloid angiopathy, sympathomimetic drugs, and coagulopathies. More recently, use of thrombolytic agents in the treatment of acute ischemic stroke has increased the risk of ICH. Treatment of intracerebral hemorrhage is based on blood pressure control, and, in selected cases, surgical evacuation of clot. Patients with aneurysmal subarachnoid hemorrhage may experience rebleeding, symptomatic vasospasm, or hydrocephalus. Medical management in the intensive care unit with careful attention to fluid and electrolyte balance, nutrition, cardiopulmonary monitoring, and close observation for changes in the neurologic exam is vital. This review examines the diagnosis and intensive care management of patients with intracerebral or subarachnoid hemorrhage, and reviews some of the newer therapies for treatment of these disorders.

Surgery in adults with tethered cord syndrome: outcome study with independent clinical review

OBJECT

The authors conducted a study to evaluate the risks and short-term benefits of surgical treatment for tethered cord syndrome (TCS) in patients older than 18 years of age.

METHODS

The authors studied a series of 57 consecutive adult patients with TCS of varying origins. Patients were examined by the same neurologist in a standardized fashion before and after surgery, and most were followed for at least 2 years postoperatively. Patient age ranged from 19 to 75 years. The mean age at onset of symptoms and diagnosis was 30 years and 37 years, respectively. Muscle strength improved (15 cases) or showed no change postoperatively (38 cases) in a large majority of patients (93%). In four patients a minor decrease in muscle strength was demonstrated, and there was significant deterioration in two (3.5%). In the two latter patients, a rapid decline in motor function was present preoperatively. Subjective assessment of pain, gait, sensory function, and bladder/bowel function at 4 weeks, 6 months, and 2 years postsurgery revealed improvement in a substantial percentage of patients. No major surgery-related complications occurred.

CONCLUSIONS

This is the largest series to date in which adult patients with TCS comprise the report. Untethering procedures in these patients were safe and effective, at least in the short term. Patients with rapid loss of motor function, lipomyelomeningocele, or split cord malformation seem to be at a higher risk of postsurgery deterioration. A follow-up period of many more years will be necessary to determine whether aggressive surgery is beneficial in the long term.