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OBJECTIVE The aim of this study was to determine differences in complications and outcomes between posterior fossa decompression with duraplasty (PFDD) and without duraplasty (PFD) for the treatment of pediatric Chiari malformation type I (CM1) and syringomyelia (SM). METHODS The authors used retrospective and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM1-SM who received PFD or PFDD and had at least 1 year of follow-up data. Preoperative, treatment, and postoperative characteristics were recorded and compared between groups. RESULTS A total of 692 patients met the inclusion criteria for this database study. PFD was performed in 117 (16.9%) and PFDD in 575 (83.1%) patients. The mean age at surgery was 9.86 years, and the mean follow-up time was 2.73 years. There were no significant differences in presenting signs or symptoms between groups, although the preoperative syrinx size was smaller in the PFD group. The PFD group had a shorter mean operating room time (p < 0.0001), fewer patients with > 50 mL of blood loss (p = 0.04), and shorter hospital stays (p = 0.0001). There were 4 intraoperative complications, all within the PFDD group (0.7%, p > 0.99). Patients undergoing PFDD had a 6-month complication rate of 24.3%, compared with 13.7% in the PFD group (p = 0.01). There were no differences between groups for postoperative complications beyond 6 months (p = 0.33). PFD patients were more likely to require revision surgery (17.9% vs 8.3%, p = 0.002). PFDD was associated with greater improvements in headaches (89.6% vs 80.8%, p = 0.04) and back pain (86.5% vs 59.1%, p = 0.01). There were no differences between groups for improvement in neurological examination findings. PFDD was associated with greater reduction in anteroposterior syrinx size (43.7% vs 26.9%, p = 0.0001) and syrinx length (18.9% vs 5.6%, p = 0.04) compared with PFD. CONCLUSIONS PFD was associated with reduced operative time and blood loss, shorter hospital stays, and fewer postoperative complications within 6 months. However, PFDD was associated with better symptom improvement and reduction in syrinx size and lower rates of revision decompression. The two surgeries have low intraoperative complication rates and comparable complication rates beyond 6 months.

OBJECTIVE The goal of this study was to assess the social determinants that influence access and outcomes for pediatric neurosurgical care for patients with Chiari malformation type I (CM-I) and syringomyelia (SM). METHODS The authors used retro- and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM-I and SM who received surgical treatment and had at least 1 year of follow-up data. Race, ethnicity, and insurance status were used as comparators for preoperative, treatment, and postoperative characteristics and outcomes. RESULTS A total of 637 patients met inclusion criteria, and race or ethnicity data were available for 603 (94.7%) patients. A total of 463 (76.8%) were non-Hispanic White (NHW) and 140 (23.2%) were non-White. The non-White patients were older at diagnosis (p = 0.002) and were more likely to have an individualized education plan (p < 0.01). More non-White than NHW patients presented with cerebellar and cranial nerve deficits (i.e., gait ataxia [p = 0.028], nystagmus [p = 0.002], dysconjugate gaze [p = 0.03], hearing loss [p = 0.003], gait instability [p = 0.003], tremor [p = 0.021], or dysmetria [p < 0.001]). Non-White patients had higher rates of skull malformation (p = 0.004), platybasia (p = 0.002), and basilar invagination (p = 0.036). Non-White patients were more likely to be treated at low-volume centers than at high-volume centers (38.7% vs 15.2%; p < 0.01). Non-White patients were older at the time of surgery (p = 0.001) and had longer operative times (p < 0.001), higher estimated blood loss (p < 0.001), and a longer hospital stay (p = 0.04). There were no major group differences in terms of treatments performed or complications. The majority of subjects used private insurance (440, 71.5%), whereas 175 (28.5%) were using Medicaid or self-pay. Private insurance was used in 42.2% of non-White patients compared to 79.8% of NHW patients (p < 0.01). There were no major differences in presentation, treatment, or outcome between insurance groups. In multivariate modeling, non-White patients were more likely to present at an older age after controlling for sex and insurance status (p < 0.01). Non-White and male patients had a longer duration of symptoms before reaching diagnosis (p = 0.033 and 0.004, respectively). CONCLUSIONS Socioeconomic and demographic factors appear to influence the presentation and management of patients with CM-I and SM. Race is associated with age and timing of diagnosis as well as operating room time, estimated blood loss, and length of hospital stay. This exploration of socioeconomic and demographic barriers to care will be useful in understanding how to improve access to pediatric neurosurgical care for patients with CM-I and SM.

OBJECTIVE The condylar–C2 sagittal vertical alignment (C-C2SVA) describes the relationship between the occipitoatlantal joint and C2 in patients with Chiari malformation type I (CM-I). It has been suggested that a C-C2SVA ≥ 5 mm is predictive of the need for occipitocervical fusion (OCF) or ventral brainstem decompression (VBD). The authors’ objective was to validate the predictive utility of the C-C2SVA by using a large, multicenter cohort of patients. METHODS This validation study used a cohort of patients derived from the Park-Reeves Syringomyelia Research Consortium; patients < 21 years old with CM-I and syringomyelia treated from June 2011 to May 2016 were identified. The primary outcome was the need for OCF and/or VBD. After patients who required OCF and/or VBD were identified, 10 age- and sex-matched controls served as comparisons for each OCF/VBD patient. The C-C2SVA (defined as the position of a plumb line from the midpoint of the O–C1 joint relative to the posterior aspect of the C2–3 disc space), pBC2 (a line perpendicular to a line from the basion to the posteroinferior aspect of the C2 body), and clival-axial angle (CXA) were measured on sagittal MRI. The secondary outcome was the need for ≥ 2 CM-related operations. RESULTS Of the 206 patients identified, 20 underwent OCF/VBD and 14 underwent repeat posterior fossa decompression. A C-C2SVA ≥ 5 mm was 100% sensitive and 86% specific for requiring OCF/VBD, with a 12.6% misclassification rate, whereas CXA < 125° was 55% sensitive and 99% specific, and pBC2 ≥ 9 was 20% sensitive and 88% specific. Kaplan-Meier analysis demonstrated that there was a significantly shorter time to second decompression in children with C-C2SVA ≥ 5 mm (p = 0.0039). The mean C-C2SVA was greater (6.13 ± 1.28 vs 3.13 ± 1.95 mm, p < 0.0001), CXA was lower (126° ± 15.4° vs 145° ± 10.7°, p < 0.05), and pBC2 was similar (7.65 ± 1.79 vs 7.02 ± 1.26 mm, p = 0.31) among those who underwent OCF/VBD versus decompression only. The intraclass correlation coefficient for the continuous measurement of C-C2SVA was 0.52; the kappa value was 0.47 for the binary categorization of C-C2SVA ≥ 5 mm. CONCLUSIONS These results validated the C-C2SVA using a large, multicenter, external cohort with 100% sensitivity, 86% specificity, and a 12.6% misclassification rate. A C-C2SVA ≥ 5 mm is highly predictive of the need for OCF/VBD in patients with CM-I. The authors recommend that this measurement be considered among the tools to identify the “high-risk” CM-I phenotype.

OBJECTIVE Odontogenic ventral brainstem compression can be a source of significant morbidity in patients with craniocervical disease. The most common methods for odontoidectomy are the transoral and endoscopic endonasal routes. In this study, the authors investigated the use of an institutional protocol for endoscopic transnasal/transoral odontoidectomy in the pediatric population. METHODS From 2007 to 2017, a multidisciplinary institutional protocol was developed and refined for the evaluation and treatment of pediatric patients requiring odontoidectomy. Preoperative assessment included airway evaluation, a sleep study (if indicated), discussion of possible tonsillectomy/adenoidectomy, and thorough imaging review by the neurosurgery and otolaryngology teams. Further preoperative anesthesia consultation was obtained for difficult airways. Intraoperatively, adenoidectomy was performed at the discretion of otolaryngology. The odontoidectomy was performed as a combined procedure. Primary posterior pharyngeal closure was performed by the otolaryngologist. The postoperative protocol called for immediate extubation, advancement to a soft diet at 24 hours, and no postoperative antibiotics. Outcome variables included time to extubation, operative time, estimated blood loss, hospital length of stay, and postoperative complications. RESULTS A total of 13 patients underwent combined endoscopic transoral/transnasal odontoid resection with at least 3 years of follow-up. All patients had stable to improved neurological function in the postoperative setting. All patients were extubated immediately after the procedure. The average operative length was 201 ± 46 minutes, and the average estimated blood loss was 44.6 ± 40.0 ml. Nine of 13 patients underwent simultaneous tonsillectomy and adenoidectomy. The average hospital length of stay was 6.6 ± 5 days. The first patient in the series required revision surgery for removal of a small residual odontoid. One patient experienced pharyngeal flap dehiscence requiring revision. CONCLUSIONS A protocolized, institutional approach for endoscopic transoral/transnasal odontoidectomy is described. The use of a combined, multidisciplinary approach leads to streamlined patient management and favorable outcomes in this complex patient population.

OBJECTIVE Posterior fossa decompression with duraplasty (PFDD) is commonly performed for Chiari I malformation (CM-I) with syringomyelia (SM). However, complication rates associated with various dural graft types are not well established. The objective of this study was to elucidate complication rates within 6 months of surgery among autograft and commonly used nonautologous grafts for pediatric patients who underwent PFDD for CM-I/SM. METHODS The Park-Reeves Syringomyelia Research Consortium database was queried for pediatric patients who had undergone PFDD for CM-I with SM. All patients had tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and ≥ 6 months of postoperative follow-up after PFDD. Complications (e.g., pseudomeningocele, CSF leak, meningitis, and hydrocephalus) and postoperative changes in syrinx size, headaches, and neck pain were compared for autograft versus nonautologous graft. RESULTS A total of 781 PFDD cases were analyzed (359 autograft, 422 nonautologous graft). Nonautologous grafts included bovine pericardium (n = 63), bovine collagen (n = 225), synthetic (n = 99), and human cadaveric allograft (n = 35). Autograft (103/359, 28.7%) had a similar overall complication rate compared to nonautologous graft (143/422, 33.9%) (p = 0.12). However, nonautologous graft was associated with significantly higher rates of pseudomeningocele (p = 0.04) and meningitis (p < 0.001). The higher rate of meningitis was influenced particularly by the higher rate of chemical meningitis (p = 0.002) versus infectious meningitis (p = 0.132). Among 4 types of nonautologous grafts, there were differences in complication rates (p = 0.02), including chemical meningitis (p = 0.01) and postoperative nausea/vomiting (p = 0.03). Allograft demonstrated the lowest complication rates overall (14.3%) and yielded significantly fewer complications compared to bovine collagen (p = 0.02) and synthetic (p = 0.003) grafts. Synthetic graft yielded higher complication rates than autograft (p = 0.01). Autograft and nonautologous graft resulted in equal improvements in syrinx size (p < 0.0001). No differences were found for postoperative changes in headaches or neck pain. CONCLUSIONS In the largest multicenter cohort to date, complication rates for dural autograft and nonautologous graft are similar after PFDD for CM-I/SM, although nonautologous graft results in higher rates of pseudomeningocele and meningitis. Rates of meningitis differ among nonautologous graft types. Autograft and nonautologous graft are equivalent for reducing syrinx size, headaches, and neck pain.

OBJECTIVEFactors associated with syrinx size in pediatric patients undergoing posterior fossa decompression (PFD) or PFD with duraplasty (PFDD) for Chiari malformation type I (CM-I) with syringomyelia (SM; CM-I+SM) are not well established.METHODSUsing the Park-Reeves Syringomyelia Research Consortium registry, the authors analyzed variables associated with syrinx radiological outcomes in patients (< 20 years old at the time of surgery) with CM-I+SM undergoing PFD or PFDD. Syrinx resolution was defined as an anteroposterior (AP) diameter of ≤ 2 mm or ≤ 3 mm or a reduction in AP diameter of ≥ 50%. Syrinx regression or progression was defined using 1) change in syrinx AP diameter (≥ 1 mm), or 2) change in syrinx length (craniocaudal, ≥ 1 vertebral level). Syrinx stability was defined as a < 1-mm change in syrinx AP diameter and no change in syrinx length.RESULTSThe authors identified 380 patients with CM-I+SM who underwent PFD or PFDD. Cox proportional hazards modeling revealed younger age at surgery and PFDD as being independently associated with syrinx resolution, defined as a ≤ 2-mm or ≤ 3-mm AP diameter or ≥ 50% reduction in AP diameter. Radiological syrinx resolution was associated with improvement in headache (p < 0.005) and neck pain (p < 0.011) after PFD or PFDD. Next, PFDD (p = 0.005), scoliosis (p = 0.007), and syrinx location across multiple spinal segments (p = 0.001) were associated with syrinx diameter regression, whereas increased preoperative frontal-occipital horn ratio (FOHR; p = 0.007) and syrinx location spanning multiple spinal segments (p = 0.04) were associated with syrinx length regression. Scoliosis (HR 0.38 [95% CI 0.16–0.91], p = 0.03) and smaller syrinx diameter (5.82 ± 3.38 vs 7.86 ± 3.05 mm; HR 0.60 [95% CI 0.34–1.03], p = 0.002) were associated with syrinx diameter stability, whereas shorter preoperative syrinx length (5.75 ± 4.01 vs 9.65 ± 4.31 levels; HR 0.21 [95% CI 0.12–0.38], p = 0.0001) and smaller pB-C2 distance (6.86 ± 1.27 vs 7.18 ± 1.38 mm; HR 1.44 [95% CI 1.02–2.05], p = 0.04) were associated with syrinx length stability. Finally, younger age at surgery (8.19 ± 5.02 vs 10.29 ± 4.25 years; HR 1.89 [95% CI 1.31–3.04], p = 0.01) was associated with syrinx diameter progression, whereas increased postoperative syrinx diameter (6.73 ± 3.64 vs 3.97 ± 3.07 mm; HR 3.10 [95% CI 1.67–5.76], p = 0.003), was associated with syrinx length progression. PFD versus PFDD was not associated with syrinx progression or reoperation rate.CONCLUSIONSThese data suggest that PFDD and age are independently associated with radiological syrinx improvement, although forthcoming results from the PFDD versus PFD randomized controlled trial (NCT02669836, clinicaltrials.gov) will best answer this question.

Currarino syndrome is an autosomal dominant condition with variable expressivity and penetrance that is associated with several classic features: sacral dysgenesis, presacral mass, and/or anorectal anomalies. The authors present a unique case in which the patient’s initial presentation was a CSF leak from a sinus tract. The sinus tract was identified and disconnected from the thecal sac, obliterating the anterior sacral meningocele. This case represents a unique scenario in which Currarino syndrome manifested as a CSF leak from a dermal sinus tract.

Psammomatoid juvenile ossifying fibroma (PJOF) is an uncommon, benign fibro-osseous tumor. It is a purely surgical disease, and a review of the literature revealed that adjuvant therapies, including chemotherapy and radiation, play a limited role. The authors report the case of a 16-year-old male refugee who presented with a giant sinonasal PJOF with parasellar invasion, after having been unable to undergo earlier surgical treatment. The delay in presentation resulted in a large lesion with bilateral optic nerve compression, blindness, and frontal lobe compression. The patient was surgically treated with a two-stage combined cranial and endoscopic endonasal surgical approach. The delay in treatment and significant neurological compromise, which necessitated a two-stage approach, are unique from previously reported cases of PJOF.

The bilateral sagittal split mandibular osteotomy (BSSMO), a common maxillofacial technique for expanding the oropharynx during treatment of micrognathia, is a rarely employed but useful adjunct to improve surgical access to the ventral cervical spine in children. Specifically, it provides enhanced exposure of the craniocervical junction in the context of midface hypoplasia, and of the subaxial cervical spine in children with severe kyphosis. The authors describe their technique for BSSMO and evaluate long-term outcomes in patients. The pediatric neurosurgical database at a single center was queried to identify children who underwent BSSMO as an adjunct to cervical spine surgery over a 22-year study period (1993–2015). The authors retrospectively reviewed clinical and radiographic data in all patients. The authors identified 5 children (mean age 5.3 ± 3.1 years, range 2.1–10.0 years) who underwent BSSMO during cervical spine surgery. The mean clinical follow-up was 3.0 ± 1.9 years. In 4 children, BSSMO was used to increase the size of the oropharynx and facilitate transoral resection of the odontoid and anterior decompression of the craniocervical junction. In 1 patient with subaxial kyphosis and chin-on-chest deformity, BSSMO was used to elevate the chin, improve anterior exposure of the subaxial cervical spine, and facilitate cervical corpectomy. Careful attention to neurovascular structures, including the inferior alveolar nerve, lingual nerve, and mental branch of the inferior alveolar artery, as well as minimizing tongue manipulation and compression, are critical to complication avoidance. The BSSMO is a rarely used but extremely versatile technique that significantly enhances anterior exposure of the craniocervical junction and subaxial cervical spine in children in whom adequate visualization of critical structures is not otherwise possible.

OBJECT There is a significant deficiency in understanding the biomechanics of the pediatric craniocervical junction (CCJ) (occiput–C2), primarily because of a lack of human pediatric cadaveric tissue and the relatively small number of treated patients. To overcome this deficiency, a finite element model (FEM) of the pediatric CCJ was created using pediatric geometry and parameterized adult material properties. The model was evaluated under the physiological range of motion (ROM) for flexion-extension, axial rotation, and lateral bending and under tensile loading. METHODS This research utilizes the FEM method, which is a numerical solution technique for discretizing and analyzing systems. The FEM method has been widely used in the field of biomechanics. A CT scan of a 13-month-old female patient was used to create the 3D geometry and surfaces of the FEM model, and an open-source FEM software suite was used to apply the material properties and boundary and loading conditions and analyze the model. The published adult ligament properties were reduced to 50%, 25%, and 10% of the original stiffness in various iterations of the model, and the resulting ROMs for flexion-extension, axial rotation, and lateral bending were compared. The flexion-extension ROMs and tensile stiffness that were predicted by the model were evaluated using previously published experimental measurements from pediatric cadaveric tissues. RESULTS The model predicted a ROM within 1 standard deviation of the published pediatric ROM data for flexion-extension at 10% of adult ligament stiffness. The model's response in terms of axial tension also coincided well with published experimental tension characterization data. The model behaved relatively stiffer in extension than in flexion. The axial rotation and lateral bending results showed symmetric ROM, but there are currently no published pediatric experimental data available for comparison. The model predicts a relatively stiffer ROM in both axial rotation and lateral bending in comparison with flexion-extension. As expected, the flexion-extension, axial rotation, and lateral bending ROMs increased with the decrease in ligament stiffness. CONCLUSIONS An FEM of the pediatric CCJ was created that accurately predicts flexion-extension ROM and axial force displacement of occiput–C2 when the ligament material properties are reduced to 10% of the published adult ligament properties. This model gives a reasonable prediction of pediatric cervical spine ligament stiffness, the relationship between flexion-extension ROM, and ligament stiffness at the CCJ. The creation of this model using open-source software means that other researchers will be able to use the model as a starting point for research.

OBJECTThe long-term consequences of atlantoaxial (AA) and occipitocervical (OC) fusion and instrumentation in young children are unknown. Anecdotal reports have raised concerns regarding altered growth and alignment of the cervical spine after surgical intervention. The purpose of this study was to determine the long-term effects of these surgeries on the growth and alignment of the maturing spine.METHODSA multiinstitutional retrospective chart review was conducted for patients less than or equal to 6 years of age who underwent OC or AA fusion with rigid instrumentation at 9 participating centers. All patients had at least 3 years of clinical and radiographic follow-up data and radiographically confirmed fusion. Preoperative, immediate postoperative, and most recent follow-up radiographs and/or CT scans were evaluated to assess changes in spinal growth and alignment.RESULTSForty children (9 who underwent AA fusion and 31 who underwent OC fusion) were included in the study (mean follow-up duration 56 months). The mean vertical growth over the fused levels in the AA fusion patients represented 30% of the growth of the cervical spine (range 10%–50%). Three different vertical growth patterns of the fusion construct developed among the 31 OC fusion patients during the follow-up period: 1) 16 patients had substantial growth (13%–46% of the total growth of the cervical spine); 2) 9 patients had no meaningful growth; and 3) 6 patients, most of whom presented with a distracted atlantooccipital dislocation, had a decrease in the height of the fused levels (range 7–23 mm). Regarding spinal alignment, 85% (34/40) of the patients had good alignment at follow-up, with straight or mildly lordotic cervical curvatures. In 1 AA fusion patient (11%) and 5 OC fusion patients (16%), we observed new hyperlordosis (range 43°–62°). There were no cases of new kyphosis or swan-neck deformity, evidence of subaxial instability, or unintended subaxial fusion. No preoperative predictors of these growth patterns or alignment were evident.CONCLUSIONSThese results demonstrate that most young children undergoing AA and OC fusion with rigid internal fixation continue to have good cervical alignment and continued growth within the fused levels during a prolonged follow-up period. However, some variability in vertical growth and alignment exists, highlighting the need to continue close long-term follow-up.

Object Chiari malformation Type I (CM-I) is a congenital anomaly often treated by decompressive surgery. Patients who fail to respond to standard surgical management often have complex anomalies of the craniovertebral junction and brainstem compression, requiring reduction and occipitocervical fusion. The authors hypothesized that a subgroup of “complex” patients defined by specific radiographic risk factors may have a higher rate of requiring occipitocervical fusion. Methods A retrospective review was conducted of clinical and radiographic data in pediatric patients undergoing surgery for CM-I between 1995 and 2010. The following radiographic criteria were identified: scoliosis, syringomyelia, CM Type 1.5, medullary kinking, basilar invagination, tonsillar descent, craniocervical angulation (clivoaxial angle [CXA] < 125°), and ventral brainstem compression (pB–C2 ≥ 9 mm). A multivariate Cox regression analysis was used to determine the independent association between occipitocervical fusion and each variable. Results Of the 206 patients who underwent CM decompression with or without occipitocervical fusion during the study period, 101 had preoperative imaging available for review and formed the study population. Mean age at surgery was 9.1 years, and mean follow-up was 2.3 years. Eighty-two patients underwent suboccipital decompression alone (mean age 8.7 years). Nineteen patients underwent occipitocervical fusion (mean age 11.1 years), either as part of the initial surgical procedure or in a delayed fashion. Factors demonstrating a significantly increased risk of requiring fusion were basilar invagination (HR 9.8, 95% CI 2.2–44.2), CM 1.5 (HR 14.7, 95% CI 1.8–122.5), and CXA < 125° (HR 3.9, 95% CI 1.2–12.6). Conclusions Patients presenting with basilar invagination, CM 1.5, and CXA < 125° are at increased risk of requiring an occipitocervical fusion procedure either as an adjunct to initial surgical decompression or in a delayed fashion. Patients and their families should be counseled in regard to these findings as part of a preoperative CM evaluation.

Object Surgical arthrodesis for pediatric occipitocervical (OC) instability has a high rate of success in a wide variety of challenging circumstances; however, identifying potential risk factors can help to target variables that should be the focus of improvement. The aim of this paper was to examine risk factors predictive of failure in a population of patients who underwent instrumented OC arthrodesis using a uniform surgical philosophy. Methods The authors conducted a retrospective cohort study of pediatric patients who underwent OC fusion from 2001 to 2013 at a single institution to determine risk factors for surgical failure, defined as reoperation for revision of the arthrodesis or instrumentation. The primary study outcome was either radiographic confirmation of successful OC fusion or surgical failure requiring revision of the arthrodesis or instrumentation. The secondary outcome was the underlying cause of failure (hardware failure, graft failure, or infection). Univariate analysis was performed to assess the association between outcome and patient demographics, cause of OC instability, type of OC instrumentation, bone graft material, biological adjuncts, and complications. Results Of the 127 procedures included, 20 (15.7%) involved some form of surgical failure and required revision surgery. Univariate analysis revealed that patients with deep wound infections requiring debridement were more likely to require surgical revision of the hardware or graft (p = 0.002). Subgroup analysis revealed that patients with skeletal dysplasia or congenital spinal anomalies were more likely to develop hardware failure than patients with other causes of OC instability (p = 0.020). Surgical failure was not associated with the method of C-2 fixation, type of rigid OC instrumentation, bone graft material, use of bone morphogenetic protein or biological adjuncts, cause of instability, sex, age, or having previous OC fusion operations. Conclusions Pediatric patients in the present cohort with postoperative wound infections requiring surgical debridement had higher surgical failure rates after OC fusion. Those with skeletal dysplasia and congenital spinal anomalies were more likely to require reoperation for hardware failure. Better understanding of the mode of surgical failure may enable surgeons to develop strategies to decrease the need for reoperation in pediatric patients with OC instability.

Object Fourth ventricle hydrocephalus, or a “trapped” fourth ventricle, presents a treatment challenge in pediatric neurosurgery. Fourth ventricle hydrocephalus develops most commonly as a result of congenital anomalies, intraventricular hemorrhage, or infection. Standard management of loculated fourth ventricle hydrocephalus consists of fourth ventricle shunt placement via a suboccipital approach. An alternative approach is stereotactic-guided transtentorial fourth ventricle shunt placement via the nondominant superior parietal lobule. In this report, the authors compare shunt survival after placement via the suboccipital and stereotactic parietal transtentorial (SPT) approaches. Methods A retrospective chart review was performed to find all patients with a fourth ventricle shunt placed between January 1, 1998, and December 31, 2011. Time to shunt failure was quantified as the number of days from shunt placement to first shunt revision or removal. Other variables studied included patient age and sex, origin of hydrocephalus, comorbidities, number of existing supratentorial catheters at the time of fourth ventricle shunt placement (as a proxy for complexity), operating surgeon, and number of previous shunt revisions. The crossover rate from one technique to the other after shunt failure from the original approach was also investigated. Results In the 29 fourth ventricle shunts placed during the study period, 18 were placed via the suboccipital approach (62.1%) and 11 via the SPT approach (37.9%). There was a statistically significant difference in time to shunt failure, with the SPT shunts lasting an average of 901 days and suboccipital shunts lasting 122 days (p = 0.04). In addition, there was a significant difference in the rate of crossover from one technique to another, with 1 SPT shunt changed to a suboccipital shunt (5.6%) and 5 suboccipital shunts changed to SPT shunts (45.5%). Conclusions Fourth ventricle shunt placement using an SPT approach resulted in significantly longer shunt survival times and lower rates of revision than the traditional suboccipital approach, despite a higher rate of crossover from previously failed shunting procedures. Stereotactic parietal transtentorial shunt placement may be considered for patients with loculated fourth ventricle hydrocephalus, especially when shunt placement via the standard suboccipital approach fails. It is therefore reasonable to offer this procedure either as a first option for the treatment of fourth ventricle hydrocephalus or when the need for fourth ventricle shunt revision arises.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant angiodysplasia with high penetrance and variable expression. The manifestations of HHT are often age related, and spinal arteriovenous fistula (AVF) may be the initial presentation of HHT in young children. Because spinal AVFs are rarely reported, however, screening is not incorporated into current clinical recommendations for the treatment of patients with HHT. The authors describe 2 cases of children younger than 2 years of age with acute neurological deterioration in the context of a spinal AVF and in whom HHT was subsequently diagnosed. One patient presented with intraventricular and subarachnoid hemorrhage and the other with acute thrombosis of an intramedullary varix. These cases highlight the potential for significant neurological morbidity from a symptomatic AVF in very young children with HHT. Given the lack of data regarding the true incidence and natural history of these lesions, these cases raise the question of whether spinal cord imaging should be incorporated into screening recommendations for patients with HHT.

Object Although rarely encountered, pediatric patients with severe cervical spine deformities and instability may occasionally require occipitocervicothoracic instrumentation and fusion. This case series reports the experience of 4 pediatric centers in managing this condition. Occipitocervical fixation is the treatment of choice for craniocervical instability that is symptomatic or threatens neurological function. In children, the most common distal fixation level with modern techniques is C-2. Treated patients maintain a significant amount of neck motion due to the flexibility of the subaxial cervical spine. Distal fixation to the thoracic spine has been reported in adult case series. This procedure is to be avoided due to the morbidity of complete loss of head and neck motion. Unfortunately, in rare cases, the pathological condition or highly aberrant anatomy may require occipitocervical constructs to include the thoracic spine. Methods The authors identified 13 patients who underwent occipitocervicothoracic fixation. Demographic, radiological, and clinical data were gathered through retrospective review of patient records from 4 institutions. Results Patients ranged from 1 to 14 years of age. There were 7 girls and 6 boys. Diagnoses included Klippel-Feil, Larsen, Morquio, and VATER syndromes as well as postlaminectomy kyphosis and severe skeletal dysplasia. Four patients were neurologically intact and 9 had myelopathy. Five children were treated with preoperative traction prior to instrumentation; 5 underwent both anterior and posterior spinal reconstruction. Two patients underwent instrumentation beyond the thoracic spine. Allograft was used anteriorly, and autologous rib grafts were used in the majority for posterior arthrodesis. Follow-up ranged from 0 to 43 months. Computed tomography confirmed fusion in 9 patients; the remaining patients were lost to follow-up or had not undergone repeat imaging at the time of writing. Patients with myelopathy either improved or stabilized. One child had mild postoperative unilateral upper-extremity weakness, and a second child died due to a tracheostomy infection. All patients had severe movement restriction as expected. Conclusions Occipitocervicothoracic stabilization may be employed to stabilize and reconstruct complex pediatric spinal deformities. Neurological function can be maintained or improved. The long-term morbidity of loss of cervical motion remains to be elucidated.

Object In late 2008, the authors recognized a new type of ventriculoperitoneal shunt failure specific to the Bio-Glide Snap Shunt ventricular catheters. This prompted a retrospective review of the patient cohort and resulted in a recall by the FDA in the US. Methods After the index cases were identified, the FDA was notified by the hospital, leading to a recall of the product. Hospital operative logs were used to identify patients in whom the affected products were used. A letter describing the risk was sent to all patients offering a free screening CT scan to look for disconnection. A call center was established to respond to patient questions, and an informational video was made available on the hospital website. The authors reviewed the records of the index cases and other cases subsequently identified. Results Seven index cases and an additional 16 cases of disconnection were identified in the 466 patients in whom a BioGlide Snap Shunt ventricular catheter had been implanted. Mean time to disconnection was 2.7 years (range 4 days–5.8 years). Computed tomography slices in the plane of the catheter helped visualize disconnections. Retrieval was difficult, and in 5 patients the disconnected catheter was not removable. Three catheters were completely within the ventricle. At presentation, 4 children suffered from severe neurological deficits, including one who died as a result of the shunt malfunction. Conclusions BioGlide snap-design ventricular catheters are prone to disconnection. Continued vigilance and specific imaging are important. Catheter removal after disconnection may be difficult. Elective removal prior to disconnection in asymptomatic children has not been performed.

Object The object of this study was to assess a multiinstitutional experience with pediatric occipitocervical constructs to determine whether a difference exists between the fusion and complication rates of constructs with or without direct C-1 instrumentation. Methods Seventy-seven cases of occiput-C2 instrumentation and fusion, performed at 9 children's hospitals, were retrospectively analyzed. Entry criteria included atlantooccipital instability with or without atlantoaxial instability. Any case involving subaxial instability was excluded. Constructs were divided into 3 groups based on the characteristics of the anchoring spinal instrumentation: Group 1, C-2 instrumentation; Group 2, C-1 and C-2 instrumentation without transarticular screw (TAS) placement; and Group 3, any TAS placement. Groups were compared based on rates of fusion and perioperative complications. Results Group 1 consisted of 16 patients (20.8%) and had a 100% rate of radiographically demonstrated fusion. Group 2 included 22 patients (28.6%), and a 100% fusion rate was achieved, although 2 cases were lost to follow-up before documented fusion. Group 3 included 39 patients (50.6%) and demonstrated a 100% radiographic fusion rate. Complication rates were 12.5, 13.7, and 5.1%, respectively. There were 3 vertebral artery injuries, 1 (4.5%) in Group 2 and 2 (5.1%) in Group 3. Conclusions High fusion rates and low complication rates were achieved with each configuration examined. There was no difference in fusion rates between the group without (Group 1) and those with (Groups 2 and 3) C-1 instrumentation. These findings indicated that in the pediatric population, excellent occipitocervical fusion rates can be accomplished without directly instrumenting C-1.