Klippel Feil Syndrome: Clinical Phenotypes Associated With Surgical Treatment.

STUDY DESIGN: Retrospective study. OBJECTIVE: To define distinct Klippel-Feil syndrome (KFS) patient phenotypes that are associated with the need for surgical intervention. SUMMARY OF BACKGROUND DATA: KFS is characterized by the congenital fusion of cervical vertebrae; however, patients often present with a variety of other spinal and extraspinal anomalies suggesting this syndrome encompasses a heterogeneous patient population. Moreover, it remains unclear how the abnormalities seen in KFS correlate to neurological outcomes and the need for surgical intervention. METHODS: Principal component (PC) analysis was performed on 132 KFS patients treated at a large pediatric hospital between 1981 and 2018. Thirty-five variables pertaining to patient/disease-related factors were examined. Significant PCs were included as independent variables in multivariable logistic regression models designed to test associations with three primary outcomes: cervical spine surgery, thoracolumbar/sacral spine surgery, and cranial surgery. RESULTS: Fourteen significant PCs accounting for 70% of the variance were identified. Five components, representing four distinct phenotypes, were significantly associated with surgical intervention. The first group consisted of predominantly subaxial cervical spine fusions, thoracic spine abnormalities and was associated with thoracolumbar/sacral spine surgery. The second group was largely represented by axial cervical spine anomalies and had high association with cervical subluxation and cervical spine surgery. A third group, heavily represented by Chiari malformation, was associated with cranial surgery. Lastly, a fourth group was defined by thoracic vertebral anomalies and associations with sacral agenesis and scoliosis. This phenotype was associated with thoracolumbar/sacral spine surgery. CONCLUSION: This is the first data-driven analysis designed to relate KFS patient phenotypes to surgical intervention and provides important insight that may inform targeted follow-up regimens and surgical decision-making. LEVEL OF EVIDENCE: 3.

Cerebellar mutism after posterior fossa tumor resection in children: a multicenter international retrospective study to determine possible modifiable factors.

PURPOSE: A preliminary survey of pediatric neurosurgeons working at different centers around the world suggested differences in clinical practice resulting in variation in the risk of pediatric cerebellar mutism (CM) and cerebellar mutism syndrome (CMS) after posterior fossa (PF) tumor resection. The purposes of this study were (1) to determine the incidence and severity of CM and CMS after midline PF tumor resection in children treated at these centers and (2) to identify potentially modifiable factors related to surgical management (rather than tumor biology) that correlate with the incidence of CM/CMS. METHODS: Attending pediatric neurosurgeons at British Columbia's Children's Hospital (BCCH) and neurosurgeons who completed a pediatric neurosurgery fellowship at BCCH were invited to provide data from the center where they currently practiced. Children aged from birth to less than 18 years who underwent initial midline PF tumor resection within a contemporary, center-selected 2-year period were included. Data was obtained by retrospective chart and imaging review. Modifiable surgical factors that were assessed included pre-resection surgical hydrocephalus treatment, surgical positioning, ultrasonic aspirator use, intraoperative external ventricular drain (EVD) use, surgical access route to the tumor, and extent of resection. CM was defined as decreased or absent speech output postoperatively and CMS as CM plus new or worsened irritability. RESULTS: There were 263 patients from 11 centers in 6 countries (Canada, Germany, the Netherlands, India, Indonesia, and the USA). Median age at surgery was 6 years (range < 1 to 17 years). The overall incidence of postoperative CM was 23.5% (range 14.7-47.6% for centers with data on ≥ 20 patients). The overall incidence of CMS was 6.5% (range 0-10.3% for centers contributing data on ≥ 20 patients). A multivariate logistic regression on the full data set showed no significant association between pre-resection surgical hydrocephalus treatment, prone position, ultrasonic aspirator use, EVD use, telovelar approach, complete or near total resection, or treating center and either postoperative CM or CMS. CONCLUSIONS: While there was variation in surgical management of midline PF tumors among centers participating in this study, the factors in management that were examined did not predict postoperative CM or CMS.

Magnetic Resonance-guided High-intensity Focused Ultrasound (MRgHIFU) Virtual Treatment Planning for Abdominal Neuroblastoma Utilizing Retrospective Diagnostic 3D CT Images.

Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) is a novel treatment for neuroblastoma using ultrasound-induced thermal ablation with real-time MR thermometry. It is unclear which patients would be amenable to MRgHIFU given the retroperitoneal location of many neuroblastomas within the smaller pediatric abdomen. In addition, planning relies on MR scans, which are not routine in the standard pediatric neuroblastoma workup. This study sought to demonstrate that neuroblastomas are targetable with MRgHIFU and available computed tomographic imaging could be utilized for MRgHIFU virtual treatment. Cross-sectional images of 88 pediatric abdominal neuroblastoma patients were retrospectively processed with custom software to be made compatible with the Sonalleve MRgHIFU platform. Targetability measured percent treatment to lesion volume, within adequate safety margins from critical structures. All images were successfully converted into treatment planning files. Median lesion size was 191±195 cm and depth was 29±17 mm. Up to 78 (85%) patients had targetable lesions with a median targetable volume of 15% and ranging up to 79%. Targetability was highest in superficial, right upper quadrant lesions >200 cm, but limited by proximity to bowel and ribs. This study demonstrates the capacity for MRgHIFU to potentially treat the majority of abdominal neuroblastomas and the feasibility of using computed tomographic images for MRgHIFU virtual treatment planning.

Laparoscopic Revision of Ventriculoperitoneal Shunts in Pediatric Patients May Result in Fewer Subsequent Peritoneal Revisions.

INTRODUCTION: Ventriculoperitoneal shunts (VPSs) are the mainstay of treatment of hydrocephalus but frequently need revision. We sought to directly compare the impact of laparoscopic versus open peritoneal shunt revision on the need for subsequent VPS revisions in pediatric patients. MATERIALS AND METHODS: A prospectively maintained, externally validated database of pediatric patients who underwent a first peritoneal VPS revision at a single center between 2008 and 2016 was reviewed. Outcomes, including subsequent revisions, shunt infections, operative time, and hospital stay between open and laparoscopic groups, were compared. RESULTS: A total of 148 patients underwent a first peritoneal VPS revision during the time period-40 laparoscopically and 108 open-with no significant difference in age or gender between the groups. Operative time, length of stay after shunt revision, and shunt infection rates did not vary between laparoscopic versus open revisions. There was no significant difference between need for subsequent overall (peritoneal or ventricular) shunt revisions in the laparoscopic (20%) versus the open group (34%), P = .07. However, there were significantly fewer frequent peritoneal revisions in the laparoscopic group (3% versus 15%, P = .04). CONCLUSIONS: This first cohort analysis of laparoscopic versus open VPS revision in pediatric patients suggests that laparoscopic peritoneal VPS revision may reduce the rate of subsequent peritoneal revisions without increasing shunt infections or operative time in pediatric patients.

Laparoscopic insertion of ventriculoperitoneal shunts in pediatric patients - A retrospective cohort study.

INTRODUCTION: Ventriculoperitoneal shunts (VPSs) are the mainstay of treatment of hydrocephalus but have frequent complications including shunt failure and infection. There has been no comparison of laparoscopic versus open primary VPS insertion in children. We hypothesized that laparoscopic VP shunt insertion may improve patient outcomes. METHODS: A prospectively-maintained, externally-validated database of pediatric patients who underwent VPS insertion at a single center between 2012 and 2016 was reviewed. Outcomes including subsequent revisions, shunt infections, operative time, and hospital stay between open and laparoscopic groups were compared. RESULTS: 210 patients underwent VPS insertion - 41 laparoscopically and 169 open. Operative time was longer for laparoscopic insertions. There was no difference in shunt infections, complications or length of stay. There was no difference between overall revisions or in confirmed peritoneal obstructions in the laparoscopic (12%) versus open VPS insertions (5%), p = 0.13. CONCLUSIONS: This first cohort analysis of laparoscopic versus open VPS insertion in pediatric patients indicates no difference in confirmed peritoneal obstructions. With increasing use of laparoscopic placement in some centers, it remains important to elucidate if there is a subset of pediatric patients who might benefit from this technique; possible candidates may be those who are overweight/obese or have had previous intra-abdominal surgery. LEVEL OF EVIDENCE: III - Retrospective cohort study.

Pediatric thalamic tumors in the MRI era: a Canadian perspective.

BACKGROUND: Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system. METHODS: We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989-2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed. RESULTS: Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53% of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13% for unithalamic tumors compared to 37 ± 32% for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive. CONCLUSION: Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.

Rotatory subluxation: experience from the Hospital for Sick Children.

OBJECT: Diagnosis and management of atlantoaxial rotatory subluxation (AARS) is challenging because of its variability in clinical presentation. Although several treatment modalities have been employed, there remains no consensus on the most appropriate therapy. The authors explore this issue in their 9-year series on AARS. METHODS: Records of patients diagnosed radiologically and clinically with AARS between May 2001 and March 2010 were retrospectively reviewed. Of 40 patients identified, 24 were male and were on average 8.5 years of age (range 15 months-16 years). Causes of AARS included trauma, congenital abnormalities, juvenile rheumatoid arthritis, infection, postsurgical event, and cryptogenic disease. Four patients had dual etiologies. Symptom duration varied: 29 patients had symptoms for less than 4 weeks, 5 patients had symptoms between 1 and 3 months, and 6 patients had symptoms for 3 months or more. RESULTS: Treatment with a cervical collar was sufficient in 21 patients. In 1 patient collar management failed and halter traction was used to reduce the subluxation. Seven patients underwent initial halter traction, but in 4 the subluxation progressed and the patients required halo traction. A halo vest was placed in 2 patients on presentation because the rotatory subluxation was severe; both patients required subsequent operative fusion. One patient required decompression and fusion due to severe canal compromise and myelopathy. All patients requiring fusion presented with subacute symptoms. CONCLUSIONS: Management of AARS varies due to the spectrum of clinical presentations. Patients presenting acutely without neurological deficits can likely undergo collar therapy; those in whom the subluxation cannot be reduced or who present with a neurological deficit may require traction and/or surgical fixation. Patients presenting subacutely may be more prone to requiring operative intervention.

Prospective surveillance of complications in a pediatric neurosurgery unit.

OBJECT: Complications of specific pediatric neurosurgical procedures are well recognized. However, focused surveillance on a specific neurosurgical unit, for all procedures, may lead to better understanding of the most important complications, and allow targeted strategies for quality improvement. METHODS: The authors prospectively recorded the morbidity and mortality events at a large pediatric neurosurgical unit over a 2-year period. Morbidity was defined as any significant adverse outcome or death (for obstructive shunt failure, within 30 days). Multiple and unrelated complications in the same patient were recorded as separate events. RESULTS: There were 1082 surgical procedures performed during the evaluation period. One hundred seventy-seven complications (16.4%) occurred in 147 patients. By procedure, the most common complications occurred in vascular surgery (41.7%) and brain tumor surgery (27.9%). The most common complications were CSF leakage (31 cases), a new neurological deficit (27 cases), early shunt or endoscopic third ventriculostomy obstruction (27 cases), and shunt infection (24 cases). Meningitis occurred in 19 cases: in 58% of shunt infections, 13% of CSF leaks, and 10% of wound infections. Sixty-four percent of adverse events required a second procedure, most commonly an external ventricular drain placement or shunt revision. CONCLUSIONS: Complications in pediatric neurosurgical procedures are common, result in significant morbidity, and more than half the time require a repeat surgical procedure. Targeted strategies to prevent common complications, such as shunt infections or CSF leaks, might significantly reduce this burden.

Predicting postresection hydrocephalus in pediatric patients with posterior fossa tumors.

OBJECT: Approximately 30% of children with posterior fossa tumors exhibit hydrocephalus after tumor resection. Recent literature has suggested that prophylactic endoscopic third ventriculostomy diminishes the risk of this event. Because the majority of patients will not have postoperative hydrocephalus, a preoperative clinical prediction rule that identifies patients at high or low risk for postresection hydrocephalus would be helpful to optimize the care of these children. METHODS: The authors evaluated a derivation cohort of 343 consecutive children with posterior fossa tumors who underwent treatment between 1989 and 2003. Multivariate methods were used on these data to generate the Canadian Preoperative Prediction Rule for Hydrocephalus. The rule's estimated risk of postresection hydrocephalus was compared with risk observed in 111 independent patients in the validation cohort. RESULTS: Variables identified as significant in predicting postresection hydrocephalus were age < 2 years (score of 3), papilledema (score of 1), moderate to severe hydrocephalus (score of 2), cerebral metastases (score of 3), and specific estimated tumor pathologies (score of 1). Patients with scores > or = 5 were deemed as high risk. Predicted probabilities for the high- and low-risk groups were 0.73 and 0.25, respectively, from the derivation cohort, and 0.59 and 0.14 after prevalence adjustment compared with the observed values of 0.42 and 0.17 in the validation cohort. CONCLUSIONS: A patient's score on the Preoperative Prediction Rule for Hydrocephalus will allow improved patient counseling and surgical planning by identifying patients at high risk of developing postresection hydrocephalus. These patients might selectively be exposed to the risks of preresection CSF diversion to improve outcome.

The changing epidemiology of paediatric brain tumours: a review from the Hospital for Sick Children.

PURPOSE: This study examines the changing epidemiology of paediatric brain tumours over the past three decades (1980-2008) in a single institution, SickKids, Toronto, Canada. METHODS: We classified 1,866 surgical pathology cases of brain tumours in children under the age of 19 according to the World Health Organization 2007 consensus and analysed them by gender, histological tumour type, age distribution and decade. RESULTS: Males showed a slightly higher predominance with 56.8% of cases overall. The main histological tumour types were low-grade (I/II) astrocytomas (26.4%), medulloblastoma (10.6%), anaplastic astrocytoma/glioblastoma multiforme (7.1%) and ependymoma (7.0%). Over three decades, an increasing proportion of certain tumour types, including pilocytic astrocytoma, atypical teratoma/rhabdoid tumours and neuronal/mixed neuronal-glial tumours was seen. CONCLUSIONS: Our results are consistent with those published with similar methodologies in other countries. Any changes in the epidemiology of childhood central nervous system tumours over the past three decades may be attributed in part to changing classification systems, improved imaging technologies and developments in epilepsy surgery; however, continued surveillance remains important.

Clinical predictors of developmental outcome in patients with cephaloceles.

OBJECT: Cephaloceles represent primary axial mesodermal defects, occurring in 0.8-4 per 10,000 live births. Prior studies have reported posterior location, hydrocephalus, microcephaly, seizure, and presence of brain tissue as poor prognostic markers for neurological outcome. However, these studies were small and the results were analyzed using univariate tests. The purpose of this study was to investigate the potential risk factors for the occurrence of developmental delay in patients with cephaloceles, using both univariate and multivariable regression techniques. METHODS: This is a retrospective cohort study of cephalocele cases treated at the Hospital for Sick Children between 1990 and 2006. Two independent investigators collected the data from the Hospital for Sick Children Encephalocele Database and hospital charts. Developmental assessments were made by general pediatricians and neuropsychologists. Both univariate analysis (alpha=0.10) and multivariable logistic regression analysis (alpha=0.05) were performed. RESULTS: Eighty-five cases of cephaloceles were identified. The patient group consisted of 48 boys and 37 girls. Sixty-eight lesions were encephaloceles and 17 were meningoceles. The distribution was as follows: frontal (40 lesions), occipital (33), and parietal (12). Associated conditions included hydrocephalus (23), seizure disorder (17), microcephaly (6), corpus callosal abnormalities (15), heterotopias (9), cerebral dysgenesis (11), and myelomeningocele (1). Evaluation of long-term development revealed that 41 patients (48%) had normal development, 9 (11%) had mild delay, 14 (16%) had moderate delay, and 21 (25%) had severe delay. Hydrocephalus, seizure disorder, microcephaly, presence of associated intracranial abnormalities, and presence of brain tissue were significantly associated with poor outcome on univariate analysis. Multivariable analysis revealed hydrocephalus and presence of intracranial abnormalities to be statistically significant predictors of developmental delay. CONCLUSIONS: To the authors' knowledge, this is one of the largest North American cephalocele series documented. Unlike prior studies, location of the cephaloceles is not a significant predictor of outcome. The multivariable regression analysis demonstrates hydrocephalus and the presence of associated intracranial abnormalities as variables with cumulative predictive effects for developmental delay.

Long-term seizure and social outcomes following temporal lobe surgery for intractable epilepsy during childhood.

PURPOSE: Studies of adults who underwent temporal lobectomy for intractable temporal lobe epilepsy (TLE) demonstrated declining seizure free rates over time. Using seizure and social parameters, we followed patients who had temporal lobe surgery (TLS) in childhood to determine long-term outcomes. METHODS: We identified 42 patients who underwent TLS for medically intractable epilepsy during childhood. Follow-up data were collected from 10 to 20 years after surgery (median, 12 years). We studied histopathology, seizure outcome, employment, school enrolment, and driver's licensing. Patients or parents graded their satisfaction with TLS. RESULTS: Number of Engel class I patients was 34 (81%) after 6 months; 32 (76%) after 1 year; 30 (71%) after 5 years; and 28 (67%) at last >or=10 years follow-up. Nineteen (79%) of 24 children with tumors or cavernous angioma achieved class I outcomes in contrast to 9 (50%) of 18 children with other pathologies (p<0.05). Ten (56%) of 18 recurrent seizure patients experienced seizures within the first year; 4 required reoperation for seizure freedom. More seizure free patients (24, 86%) than residual seizure patients (8, 57%) were employed or in school (p=0.05). Twelve (63%) of 19 eligible patients obtained driver's licenses. Twenty-three (82%) of 28 seizure free patients discontinued anticonvulsants. Surgery grading averaged "satisfied." Class I patients reported greater satisfaction than class III/IV patients (p<0.001). CONCLUSION: Two-thirds of children who underwent TLS achieved seizure freedom at >or=10 year follow-up. Children with tumors or cavernous angiomas achieved better long-term outcomes than those with other histopathologies. Long-term seizure free patients were most often satisfied with surgery and employed or in school.

Long-term outcome of hydrocephalus management in myelomeningoceles.

BACKGROUND: The cerebrospinal fluid (CSF) shunt remains an important ongoing management problem in myelomeningocele (MMC) patients. We reviewed the long-term shunt treatment outcome in a prospectively followed group of MMC patients from a single institution. METHOD: Patients prospectively entered into a hydrocephalus database with a diagnosis of MMC from the years 1987 to 1996 were selected. All data was verified from the medical records and additional details about the shunt surgery were collected. The outcome of shunt failure was categorized as shunt obstruction, shunt infection, presence of loculated ventricles, overdrainage, and other. All deaths were recorded and causation identified. Univariate analysis for shunt failure risk factors was accomplished using Log rank statistics. Multivariable analysis was performed for each repeated failure level using a conditional Cox regression model. RESULTS: One hundred and twenty (64%) out of 189 MMC patients experienced a first shunt failure with a median time of 303 days; 29 (24%) of the failures were due to shunt infection (the procedure infection rate being 15%). Sixty-one patients experienced a second shunt failure, 38 a third and 36 had four or more. Multivariable analysis of risk factors failed to demonstrate any clear risk factors for either first or subsequent shunt failure. Fifteen patients died, 13 from either shunt or Chiari 1 complications. CONCLUSION: Shunt complications remain an important cause of morbidity and mortality in MMC patients, particularly shunt infection.