Predictors of syrinx presentation and outcomes in pediatric Chiari malformation type I: a single institution experience of 218 consecutive syrinx patients.

PURPOSE: Chiari I malformation (CM-I) in pediatric patients can impose substantial neurologic and functional impairment. Additionally, the presence of syrinx is often a harbinger of clinical compromise, but little attention has been devoted to identifying features associated with syrinx development and the clinical impact of syrinx resolution. Therefore, this study aims to identify clinical and radiographic variables associated with preoperative syrinx presence and postoperative syrinx reduction in pediatric patients with CM-I and determine the relationship between postoperative syrinx reduction and clinical symptom improvement. METHODS: The authors performed a retrospective analysis of 435 consecutive pediatric patients who underwent surgical treatment of CM-I from 2001 to 2021 at a single tertiary pediatric medical center. All patients underwent pre- and postoperative MRI, and clinical and radiographic variables were recorded and subject to inferential analysis. RESULTS: Syrinx at presentation was independently associated with symptoms of spinal cord dysfunction at presentation (OR 2.17 (95% CI 1.05-4.48); p = 0.036), scoliosis (OR 5.33 (2.34-10.86); p = 0.001), and greater pB-C2 (posterior basion to C2 distance) measurement length (OR 1.14 (95% CI 1.01-1.30); p = 0.040). Syrinx at presentation was inversely associated with tussive headaches at presentation (OR 0.27 (95% CI 0.16-0.47); p = 0.001) and cranial nerve deficits at presentation (OR 0.49 (95% CI 0.26-0.92); p = 0.025). Postoperatively, patients with radiographic evidence of syrinx improvement had greater rates of symptom improvement (93.1% vs 82.1%; p = 0.049), better CCOS scores (15.4 vs 14.2; p = 0.001), and decreased rates of readmission (6.0% vs 25.0%, p = 0.002) and reoperation (0.5% vs 35.7%; p = 0.001). The difference in syrinx resolution was similar but not statistically significant (10.3% vs 16.7%; p = 0.251). AO joint anomaly (OR 0.20, 95% CI 0.04-0.95; p = 0.026) and foramen magnum diameter (OR 1.12, 95% CI 1.00-1.25; p = 0.049) were the only independent predictors of syrinx improvement, and surgical technique was the only predictor for syrinx resolution (OR 2.44, 95% CI 1.08-5.50; p = 0.031). Patients that underwent tonsil reduction surgery whose syrinx improved had a wider foramen magnum diameter than those whose did not improve (34.3 vs 31.7; p = 0.028). CONCLUSIONS: Radiographic syrinx improvement is associated with greater rates of symptom improvement and less readmissions and reoperations for CM-I. AO joint anomalies and narrower foramen magnums were independent risk factors for the lack of syrinx improvement. These novel insights will help guide preoperative patient counseling, pre- and intraoperative surgical decision-making, and postoperative clinical prognostication in the treatment of pediatric CM-I.

Management of cerebrospinal fluid pseudocysts in the laparoscopic age.

OBJECTIVE: Abdominal CSF pseudocysts are an uncommon but challenging complication of ventriculoperitoneal shunts. Pseudocysts consist of a loculated intraperitoneal compartment that inadequately absorbs CSF and may be infected or sterile at diagnosis. The treatment goal is to clear infection if present, reduce inflammation, and reestablish long-term function in an absorptive (intraperitoneal) space. This aim of this paper was to study the efficacy of primary laparoscopic repositioning of the distal shunt catheter for treatment of sterile abdominal CSF pseudocysts. METHODS: All patients treated for abdominal CSF pseudocysts at Dallas Children's Health from 1991 to 2021 were retrospectively reviewed. Patient history and pseudocyst characteristics were analyzed, with a primary outcome of pseudocyst recurrence at 1 year. RESULTS: Of 92 primary pseudocysts, 5 initial treatment strategies (groups) were used depending on culture status, clinical history, and surgeon preference: 1) shunt explant/external ventricular drain (EVD) placement (23/92), 2) distal tubing externalization (13/92), 3) laparoscopic repositioning (35/92), 4) open repositioning (4/92), and 5) other methods such as pseudocyst drainage or direct revision to another terminus (17/92). Seventy pseudocysts underwent shunt reimplantation in the peritoneal space. The 1-year peritoneal shunt survival for groups 1 and 2 combined was 90%, and 62% for group 3. In group 3, 1-year survival was better for those with normal systemic inflammatory markers (100%) than for those with high markers (47%) (p = 0.042). In a univariate Cox proportional hazards model, the risk of pseudocyst recurrence was increased if the most recent abdominal procedure was a nonshunt abdominal surgery (p = 0.012), and it approached statistical significance with male sex (p = 0.054) and elevated inflammatory markers (p = 0.056. Multivariate Cox analysis suggested increased recurrence risk with male sex (p = 0.05) and elevated inflammatory markers (p = 0.06), although the statistical significance threshold was not reached. The length of hospital stay was shorter for laparoscopic repositioning (6 days) than for explantation/EVD placement (21 days) (p < 0.0001). Ultimately, 62% of patients had a peritoneal terminus at the last follow-up, 33% (n = 30) had an extraperitoneal terminus (19 pleura, 8 right heart, and 3 gallbladder), and 5 patients were shunt free. CONCLUSIONS: Some sterile pseudocysts with normal systemic inflammatory markers can be effectively treated with laparoscopic repositioning, resulting in a significantly shorter hospitalization and modestly higher recurrence rate than shunt explantation.

Cerebellar tonsil reduction for surgical treatment of Chiari malformation type I in children.

OBJECTIVE: The goal of this study was to review the efficacy and safety of different surgical techniques used for treatment of Chiari malformation type I (CM-I) in children. METHODS: The authors retrospectively reviewed 437 consecutive children surgically treated for CM-I. Procedures were classified into four groups: bone decompression (posterior fossa decompression [PFD]) and duraplasty (PFD with duraplasty [PFDD]), PFDD with arachnoid dissection (PFDD+AD), PFDD with tonsil coagulation of at least one cerebellar tonsil (PFDD+TC), and PFDD with subpial tonsil resection of at least one tonsil (PFDD+TR). Efficacy was measured as a greater than 50% reduction in the syrinx by length or anteroposterior width, patient-reported improvement in symptoms, and rate of reoperation. Safety was measured as the rate of postoperative complications. RESULTS: The mean patient age was 8.4 years (range 3 months to 18 years). In total, 221 (50.6%) patients had syringomyelia. The mean follow-up was 31.1 months (range 3-199 months), and there was no statistically significant difference between groups (p = 0.474). Preoperatively, univariate analysis showed that non-Chiari headache, hydrocephalus, tonsil length, and distance from the opisthion to brainstem were associated with the surgical technique used. Multivariate analysis demonstrated that hydrocephalus was independently associated with PFD+AD (p = 0.028), tonsil length was independently associated with PFD+TC (p = 0.001) and PFD+TR (p = 0.044), and non-Chiari headache was inversely associated with PFD+TR (p = 0.001). In the treatment groups postoperatively, symptoms improved in 57/69 (82.6%) PFDD patients, 20/21 (95.2%) PFDD+AD patients, 79/90 (87.8%) PFDD+TC patients, and 231/257 (89.9%) PFDD+TR patients, and differences between groups were not statistically significant. Similarly, there was no statistically significant difference in postoperative Chicago Chiari Outcome Scale scores between groups (p = 0.174). Syringomyelia improved in 79.8% of PFDD+TC/TR patients versus only 58.7% of PFDD+AD patients (p = 0.003). PFDD+TC/TR remained independently associated with improved syrinx outcomes (p = 0.005) after controlling for which surgeon performed the operation. For those patients whose syrinx did not resolve, no statistically significant differences between surgery groups were observed in the length of follow-up or time to reoperation. Overall, there was no statistically significant difference between groups in postoperative complication rates, including aseptic meningitis and CSF- and wound-related issues, or reoperation rates. CONCLUSIONS: In this single-center retrospective series, cerebellar tonsil reduction, by either coagulation or subpial resection, resulted in superior reduction of syringomyelia in pediatric CM-I patients, without increased complications.

Risk factors for clinical and radiological worsening following Chiari malformation type I surgery in the pediatric population.

OBJECTIVE: Foramen magnum (FM) decompression with or without duraplasty is considered a common treatment strategy for Chiari malformation type I (CM-I). The authors' objective was to determine a predictive model of risk factors for clinical and radiological worsening after CM-I surgery. METHODS: A retrospective review of electronic health records was conducted at an academic tertiary care hospital from 2001 to 2019. A multivariable Cox proportional hazards regression model was used to determine the risk factors. The Kaplan-Meier estimate was plotted to delineate outcomes based on FM size. FM was measured as the preoperative distance between the basion and opisthion and dichotomized into < 34 mm and ≥ 34 mm. Syrinx was measured preoperatively and postoperatively in the craniocaudal and anteroposterior directions using a T2-weighted MRI sequence. RESULTS: A total of 454 patients (231 females [50.9%]) with a median (range) age of 8.0 (0-18) years were included in the study. The median duration of follow-up was 21.0 months (range 3.0-144.0 years). The model suggested that patients with symptoms consisting of occipital/tussive headache (HR 4.05, 95% CI 1.34-12.17, p = 0.01), cranial nerve symptoms (HR 3.46, 95% CI 1.16-10.2, p = 0.02), and brainstem/spinal cord symptoms (HR 3.25, 95% CI 1.01-11.49, p = 0.05) had higher risk, whereas those who underwent arachnoid dissection/adhesion lysis had 75% lower likelihood (HR 0.25, 95% CI 0.10-0.64, p = 0.004) of clinical worsening postoperatively. Similarly, patients with evidence of brainstem/spinal cord symptoms (HR 7.9, 95% CI 2.84-9.50, p = 0.03), scoliosis (HR 1.04, 95% CI 1.01-2.80, p = 0.04), and preoperative syrinx (HR 16.1, 95% CI 1.95-132.7, p = 0.03) had significantly higher likelihood of postoperative worsening of syrinx. Patients with symptoms consisting of occipital/tussive headache (HR 5.44, 95% CI 1.86-15.9, p = 0.002), cranial nerve symptoms (HR 2.80, 95% CI 1.02-7.68, p = 0.04), and nonspecific symptoms (HR 6.70, 95% CI 1.99-22.6, p = 0.002) had significantly higher likelihood, whereas patients with FM ≥ 34 mm and those who underwent arachnoid dissection/adhesion lysis had 73% (HR 0.27, 95% CI 0.08-0.89, p = 0.03) and 70% (HR 0.30, 95% CI 0.12-0.73, p = 0.008) lower likelihood of reoperation, respectively. The Kaplan-Meier curve showed that patients with FM size ≥ 34 mm had significantly better clinical (p = 0.02) and syrinx (p = 0.03) improvement postoperatively when the tonsils were resected. CONCLUSIONS: These results showed that preoperative and intraoperative factors may help to provide better clinical decision-making for CM-I surgery. Patients with FM size ≥ 34 mm may have better outcomes when the tonsils are resected.

Hydrocephalus in achondroplasia: efficacy of endoscopic third ventriculostomy.

OBJECTIVE: Ventriculoperitoneal shunts (VPSs) for hydrocephalus in patients with achondroplasia are known to have a higher failure rate than in other hydrocephalus populations. However, the etiology of hydrocephalus in this group is considered "communicating," and, therefore, potentially not amenable to endoscopic third ventriculostomy (ETV). ETV has, nonetheless, been reported to be successful in a small number of patients with achondroplasia. The authors aimed to investigate the long-term results of ETV in this population. METHODS: Patients with achondroplasia who had undergone surgical treatment for hydrocephalus (ETV or VPS placement) were identified. In patients who had undergone ETV, medical records and neuroimages were reviewed to determine ventricular volumes and frontal and occipital horn ratios (FOHRs) pre- and postoperatively, as well as the incidence of surgical complications and reoperation. Patients who underwent VPS placement were included for historical comparison, and their medical records were reviewed for basic demographic information as well as the incidence of surgical complications and reoperation. RESULTS: Of 114 pediatric patients with achondroplasia referred for neurosurgical consultation, 19 (17%) were treated for hydrocephalus; 10 patients underwent ETV only, 7 patients underwent VPS placement only, and 2 patients had a VPS placed followed by ETV. In patients treated with ETV, ventricular volume and FOHRs were normal, if measured at birth, and increased significantly until the time of the ETV. After ETV, all patients demonstrated significant and sustained decreases in ventricular measurements with surveillance up to 15 years. There was a statistically significant difference in rates of repeat CSF surgery between the ETV and VPS cohorts (0/12 vs 7/9, p < 0.001). CONCLUSIONS: ETV was efficacious, safe, and durable in the treatment of hydrocephalus in patients with achondroplasia. Although many studies have indicated that hydrocephalus in these patients is "communicating," a subset may develop an "obstructive" component that is progressive and responsive to ETV.

Dynamic compression in vertebral artery dissection in children: apropos of a new protocol.

PURPOSE: Our goals are (1) to report a consecutive prospective series of children who had posterior circulation stroke caused by vertebral artery dissection at the V3 segment; (2) to describe a configuration of the vertebral artery that may predispose to rotational compression; and (3) to recommend a new protocol for evaluation and treatment of vertebral artery dissection at V3. METHODS: All children diagnosed with vertebral artery dissection at the V3 segment from September 2014 to July 2020 at our institution were included in the study. Demographic, clinical, surgical, and radiological data were collected. RESULTS: Sixteen children were found to have dissection at a specific segment of the vertebral artery. Fourteen patients were male. Eleven were found to have compression on rotation during a provocative angiogram. All eleven underwent C1C2 posterior fusion as part of their treatment. Their mean age was 6.44 years (range 18 months-15 years). Mean blood loss was 57.7 mL. One minor complication occurred: a superficial wound infection treated with oral antibiotics only. There were no vascular or neurologic injuries. There have been no recurrent ischemic events after diagnosis and/or treatment. Mean follow-up was 33.3 months (range 2-59 months). We designed a new protocol to manage V3 dissections in children. CONCLUSION: Posterior C1C2 fusion is a safe and effective option for treatment of dynamic compression in vertebral artery dissection in children. Institution of and compliance with a strict diagnostic and treatment protocol for V3 segment dissections seem to prevent recurrent stroke.

Margin-Free Fractionated Stereotactic Radiation Therapy for Pediatric Brain Tumors.

PURPOSE: Conventional radiation therapy (RT) to pediatric brain tumors exposes a large volume of normal brain to unwarranted radiation causing late toxicity. We hypothesized that in well demarcated pediatric tumors lacking microscopic extensions, fractionated stereotactic RT (SRT), without target volume expansions, can reduce high dose normal tissue irradiation without affecting local control. METHODS AND MATERIALS: Between 2008 and 2017, 52 pediatric patients with brain tumors were treated using the CyberKnife (CK) with SRT in 180 to 200 cGy per fraction. Thirty representative cases were retrospectively planned for intensity modulated RT (IMRT) with 4-mm PTV expansion. We calculated the volume of normal tissue within the high or intermediate dose region adjacent to the target. Plan quality and radiation dose-volume dosimetry parameters were compared between CK and IMRT plans. We also reported overall survival, progression-free survival (PFS), and local control. RESULTS: Tumors included low-grade gliomas (n = 28), craniopharyngiomas (n = 16), and ependymomas (n = 8). The volumes of normal tissue receiving high (≥80% of prescription dose or ≥40 Gy) or intermediate (80% > dose ≥50% of the prescription dose or 40 Gy > dose ≥25 Gy) dose were significantly smaller with CK versus IMRT plans (P < .0001 for all comparisons). With a median follow-up of 3.7 years (range, 0.1-9.0), 3-year local control was 92% for all patients. Eight failures occurred: 1 craniopharyngioma (marginal), 2 ependymomas (both in-field), and 5 low-grade gliomas (2 in-field, 1 marginal, and 2 distant). CONCLUSIONS: Fractionated SRT using CK without target volume expansion appears to reduce the volume of irradiated tissue without majorly compromising local control in pediatric demarcated brain tumors. These results are hypothesis generating and should be tested and validated in prospective studies.

Cranial and ventricular size following shunting or endoscopic third ventriculostomy (ETV) in infants with aqueductal stenosis: further insights from the International Infant Hydrocephalus Study (IIHS).

PURPOSE: The craniometrics of head circumference (HC) and ventricular size are part of the clinical assessment of infants with hydrocephalus and are often utilized in conjunction with other clinical and radiological parameters to determine the success of treatment. We aimed to assess the effect of endoscopic third ventriculostomy (ETV) and shunting on craniometric measurements during the follow-up of a cohort of infants with symptomatic triventricular hydrocephalus secondary to aqueductal stenosis. METHODS: We performed a post hoc analysis of data from the International Infant Hydrocephalus Study (IIHS)-a prospective, multicenter study of infants (< 24 months old) with hydrocephalus from aqueductal stenosis who were treated with either an ETV or shunt. During various stages of a 5-year follow-up period, the following craniometrics were measured: HC, HC centile, HC z-score, and frontal-occipital horn ratio (FOR). Data were compared in an analysis of covariance, adjusting for baseline variables including age at surgery and sex. RESULTS: Of 158 enrolled patients, 115 underwent an ETV, while 43 received a shunt. Both procedures led to improvements in the mean HC centile position and z-score, a trend which continued until the 5-year assessment point. A similar trend was noted for FOR which was measured at 12 months and 3 years following initial treatment. Although the values were consistently higher for ETV compared with shunt, the differences in HC value, centile, and z-score were not significant. ETV was associated with a significantly higher FOR compared with shunting at 12 months (0.52 vs 0.44; p = 0.002) and 3 years (0.46 vs 0.38; p = 0.03) of follow-up. CONCLUSION: ETV and shunting led to improvements in HC centile, z-score, and FOR measurements during long-term follow-up of infants with hydrocephalus secondary to aqueductal stenosis. Head size did not significantly differ between the treatment groups during follow-up, however ventricle size was greater in those undergoing ETV when measured at 1 and 3 years following treatment.

Thirty-day readmission risk after intracranial tumor resection surgeries in children.

OBJECTIVE: The risk of readmission after brain tumor resection among pediatric patients has not been defined. The authors' objective was to evaluate the readmission rates and predictors of readmission after pediatric brain tumor resection. METHODS: Nationwide Readmissions Database (NRD) data sets from 2010 to 2014 were searched for unplanned readmissions within 30 days of the discharge date after pediatric brain tumor resection. Patient demographic variables included sex, age, expected payment source (Medicaid or private insurance), and median annual household income. Readmission events for chemotherapy, radiation therapy, or further tumor resection were not included. RESULTS: Of 282 patients (12.7%) readmitted within 30 days of the index event, the median time to readmission was 10 days (IQR 5-19 days). The most common reason for readmission was hydrocephalus, which accounted for 19% of readmission events. Other CNS-related complications (24%), surgical site infections or septicemia (14%), seizures (7%), and hematological disorders (7%) accounted for other major readmission events. The median charge for readmission events was $35,431, and the median length of readmission stay was 4 days. In multivariate regression, factors associated with a significant increase in readmission risk included Medicaid as the primary payor, discharge from the index event with home health services, and fluid and electrolyte disorders during the index event. CONCLUSIONS: More than 10% of pediatric brain tumor patients have unplanned readmission events within 30 days of discharge after tumor resection. Medicaid patients and those with preoperative or early postoperative fluid and electrolyte disturbances may benefit from early or frequent outpatient visits after tumor resection.

Predictors of 90-Day Readmission in Children Undergoing Spinal Cord Tumor Surgery: A Nationwide Readmissions Database Analysis.

OBJECTIVE: A fair number of hospital admissions occur after 30 days; thus, the true readmission rate could have been underestimated. Therefore, we hypothesized that the 90-day readmission rate might better characterize the factors contributing to readmission for pediatric patients undergoing spinal tumor resection. METHODS: The Nationwide Readmissions Database was used to study the patient demographic data, comorbidities, admissions, hospital course, spinal tumor behavior (malignant vs. benign), complications, revisions, and 30- and 90-day readmissions. RESULTS: Of the 397 patients included in the 30-day cohort, 43 (10.8%) had been readmitted. In comparison, the 90-day readmission rate was significantly greater; 52 of 325 patients were readmitted (16.0%; P < 0.04). Patients aged 16-20 constituted the largest subgroup. However, the highest readmission rate was observed for patients aged <5 years (30-day, 21.7%; 90-day, 26.4%). Medicaid patients were more likely to be readmitted than were private insurance patients (30-day odds ratio [OR], 3.3 [P < 0.001]; 90-day OR, 2.29 [P < 0.02]). In both cohorts, patients with malignant tumors required readmission more often than did those with benign tumors (30-day OR, 2.78 [P < 0.02]; 90-day OR, 1.92 [P = 0.08]). In the 90-day cohort, the patients had been readmitted 26.4 days after discharge versus 10.6 days in the 30-day cohort. Within the 90-day cohort, 18.6% of the readmissions were for spinal reoperation, 28.3% for chemotherapy or hematologic complications, and 25.6% for other central nervous system disorders. The median charges for each readmission were ∼$50,000 and ∼$40,000 for the 30- and 90-day cohorts, respectively. Medicaid insurance, malignant tumors, and younger age were significant predictors of readmission in the 90-day cohort. CONCLUSIONS: The prevalence and charges associated with unplanned hospital readmissions after spinal tumor resection were remarkably high. Younger age, Medicaid insurance, malignant tumors, and complications during the initial admission were significant predictors of 90-day readmission.

Risk Factors for Wound Infections after Deformity Correction Surgery in Neuromuscular Scoliosis.

OBJECTIVE: This study aims to elucidate surgical risk factors in neuromuscular scoliosis (NMS) with respect to wound site infection after spinal fusion. METHODS: A retrospective review was performed of all patients treated surgically for NMS between January 2008 and December 2016 (minimum 6 months' follow-up). A sub-cohort of 60 patients with minimum 2 years of follow-up data was also analyzed. RESULTS: In 102 patients (53 boys and 49 girls), the mean age at surgery was 14.0 years (SD ±2.7). Mean follow-up was 2.53 years (±1.66), and mean time to presentation of infection was 2.14 months (±4.95). The overall perioperative complication rate was 26.5%, with 14.7% of patients developing deep wound infection. Gram-negative bacteria were responsible for 60% of infections; 20% were Gram positive, and 20% involved both types. Pulmonary comorbidities (p = 0.007), pre- to postoperative increase in weight (p = 0.010), exaggerated lumbar lordosis at follow-up (p = 0.008), history of seizures (p = 0.046), previous myelomeningocele repair (p = 0.046), and previous operations (p = 0.013) were significant risk factors for infection. CONCLUSION: Our data suggest that in the pediatric population treated surgically for NMS, wound infection is strongly associated with postoperative increase in body weight, residual lumbar lordosis, pulmonary comorbidity, history of myelomeningocele repair, seizures, and previous operations.

Intracranial complications of acute sinusitis in children: The role of endoscopic sinus surgery.

OBJECTIVE: To study the role of endoscopic sinus surgery (ESS) in the management of intracranial complications of children with acute rhinosinusitis METHODS: Retrospective chart review at a tertiary care pediatric hospital MAIN OUTCOMES: Demographics, intracranial complications, length of hospital stay (LOS), neurological sequelae, ESS, neurosurgical procedures RESULTS: Twenty-four children with a mean age (SD) of 12.9 years (+/-3.2) with an intracranial complication(s) of acute rhinosinusitis were identified between 2005-2016. A total of 22 were included and 15 (68%) of these were males. The most common complications were: subdural abscess (n=10), epidural abscess (n=10), meningitis (n=5), intraparenchymal abscess (n=5), and cavernous sinus thrombosis (n= 2). Neurologic symptoms included headache (n=12), hemiparesis (n=5) and aphasia (n=3). Average length of stay was 16 (+/- 9.2) days. Average follow up was 7 (+/-5.6) months. One patient had residual seizures and 1 had recurrent rhinosinusitis. Aphasia and hemiparesis resolved in all patients within 1 year. Nineteen (86%) patients had ESS within 4 days of admission. Fourteen patients (63%) had a neurosurgical procedure, 6 (27%) required more than 1 neurosurgical procedure. Six patients (27%) had concurrent neurosurgical drainage and ESS. Four patients (17%) had neurosurgical procedure followed by ESS and 3 patients (13%) were treated only by a neurosurgical procedure. Patients who underwent ESS prior to a neurosurgical procedure had significantly less risk of needing a neurosurgical intervention (OR = .02, p < .01). There was a significantly higher proportion of neurosurgical patients with positive Strep anginosus cultures compared to the ESS only group (85.7% vs 37.5%, p = .02). Studies with larger patient populations are needed to determine the role of ESS in the management of intracranial complications of children with acute rhinosinusitis. DISCUSSION: Early ESS may be associated with less need for neurosurgical procedures.

Long-term follow-up of superior gluteal artery perforator flap closure of large myelomeningoceles.

OBJECTIVE Large myelomeningocele defects and poor surrounding tissue quality make some defects particularly difficult to close primarily. This paper describes the superior gluteal artery perforator (SGAP) flap technique for defect closure and long-term clinical outcomes. METHODS The technique for closing a myelomeningocele with an SGAP flap is described. A retrospective chart review was performed on a cohort of 11 patients who underwent closure in this manner. RESULTS Between 1999 and 2015, 271 myelomeningoceles were closed, 11 of which were SGAP flap closures. The mean defect size was 5.5 × 7.2 cm. All patients underwent ventriculoperitoneal shunting. There were no cases of CSF infection. Five patients had minor wound issues (small dehiscence or eschar formation) that healed satisfactorily. Two patients had soft-tissue wound infections and required multiple revisions; one patient had multiple severe developmental abnormalities, and the other patient's flap had healed with a thick underlying fat pad 4 months postoperatively. No patients had significant surgical site pain on long-term follow-up. CONCLUSIONS The SGAP flap technique achieves tension-free closure with vascularized, fat-bearing full-thickness skin. It is useful for closure of large, complex defects, is not associated with chronic pain, and carries a morbidity risk that is comparable to other complex myelomeningocele closure techniques.

A unifying theory for the multifactorial origin of cerebellar tonsillar herniation and hydrocephalus in osteopetrosis.

OBJECT: Osteopetrosis is a rare congenital metabolic bone disease. There are very few reports in the literature associating cerebellar tonsillar herniation (CTH) and hydrocephalus requiring neurosurgical attention. The authors present cases of osteopetrosis requiring neurosurgical intervention from their practice and offer a detailed account of the literature. METHODS: A retrospective review was conducted at the authors' institution, and all children with osteopetrosis requiring neurosurgical attention were identified. Medical charts and radiographic studies were reviewed. Data including age at presentation, sex, symptoms at presentation, age at follow-up, the presence of any neurological comorbidities, and surgical procedures performed were recorded. RESULTS: Four patients were identified as having osteopetrosis requiring neurosurgical attention at the authors' institution between January 1, 2005, and January 1, 2014. There were 3 females and 1 male with an average age at presentation of 11.1 years; patients were observed for a mean of 4.4 years. All of the patients were identified as harboring jugular foraminal stenosis and CTH. Seventy-five percent of these patients developed hydrocephalus, and in those cases a triventricular pattern of dilation was noted. One patient developed syringomyelia. Three of the 4 patients underwent neurosurgical procedures. Cerebrospinal fluid diversion was performed in 2 patients via a ventriculoperitoneal shunt in one case and an endoscopic third ventriculostomy (ETV) in the other. The former patient required a proximal revision at 2 years for bony overgrowth at the site of the bur hole. Two patients underwent a suboccipital decompression. In patients undergoing CSF diversion, there was improvement in ventricle size. CONCLUSIONS: Variable degrees of hindbrain crowding and/or CTH are mentioned throughout the literature, suggesting that this entity is nearly always present in this patient population. The progressive triventricular hydrocephalus seen in these cases results from a complex combination of both communicating and noncommunicating pathology, which may depend on the type of osteopetrosis, age at presentation, and the presence and degree of venous collateralization, and it appears that the hydrocephalus is more prevalent and more likely to be treated in infants and in the younger, school-aged population. The acquired hindbrain fullness in conjunction with the triventricular pattern of hydrocephalus has kept the authors enthusiastic regarding the use of ETV in these complicated cases.

Intraocular pressure in pediatric patients during prone surgery.

BACKGROUND: Intraoperative intraocular pressure (IOP) in the prone position and IOP changes over time have not been evaluated in pediatric surgical patients. We sought to determine time-dependent changes in IOP in children undergoing surgery in prone position. METHODS: Thirty patients undergoing neurosurgical procedures in prone position were included. Using a pulse-mode pneumatonometer, IOP was measured in supine position after induction and before emergence of anesthesia and in prone position before the start and after the end of surgery. IOP changes over time in the prone position were assessed with a linear mixed model (i.e., random slope and intercept model) to adjust for the within-patient correlation. RESULTS: IOP in prone position increased by an average of 2.2 mm Hg per hour (P < 0.001). Sixty-three percent of patients (95% confidence interval [CI], 46%-81%) had at least 1 IOP value exceeding 30 mm Hg, and 13% (95% CI, 1%-25%) had at least 1 IOP value exceeding 40 mm Hg while prone. Mean IOP increased 7 mm Hg (95% CI, 6-9) during the position change from supine to prone (P < 0.001) and decreased 10 mm Hg (95% CI, 9-12) after changing the position from prone back to supine (P < 0.001). CONCLUSIONS: Changing position from supine to prone significantly increases IOP in anesthetized pediatric patients. Moreover, the IOP continued to increase during surgery and reached potentially harmful values, especially when combined with low mean arterial blood pressures that are common during major surgery.

Endoscopic third ventriculostomy in hydrocephalus associated with achondroplasia.

Hydrocephalus in patients with achondroplasia is thought to be due to increased dural sinus venous pressure resulting from narrowing of the jugular foramen. In this setting, where hydrocephalus is presumed to be "vascular" in origin and therefore communicating, endoscopic third ventriculostomy (ETV) would seem contraindicated. The authors describe 3 patients in whom ETV was successfully performed, resulting in MR imaging-documented decreases in ventricle size. The patients were 11 months, 33 months, and 13 years at the time of surgery. All patients had serial preoperative MR images demonstrating progressive hydrocephalus in a "triventricular" pattern with a small fourth ventricle but an open aqueduct. All patients had undergone suboccipital decompression for foramen magnum stenosis prior to the treatment of hydrocephalus. Preoperative retrograde venography revealed variable pressure gradients across the jugular foramen. It is postulated that the increase in intracranial venous pressure resulting from jugular foramen stenosis may lead to disproportionate venous engorgement of the cerebellum and some degree of obstructive hydrocephalus amenable to ETV. The authors discuss the role of suboccipital decompression in the progression of hydrocephalus in patients with achondroplasia.

Limited reduction cranioplasty for the treatment of hydrocephalic macrocephaly.

BACKGROUND: Hydrocephalic macrocephaly, occurring despite adequate cerebrospinal fluid shunting, is rare, and most publications advocate near-total cranial vault reduction procedures. The authors reviewed our series of limited reductions (designed to minimize complications while still providing functional benefits) to evaluate outcomes. METHODS: All patients undergoing posterior reduction cranioplasties were retrospectively reviewed for outcomes, including operative data, length of stay, preoperative and postoperative anthropometrics, and complications. In addition, preoperative and postoperative motor function was assessed using a novel scale. These data were then compared with published series. RESULTS: Ten patients (five male, five female) underwent reduction cranioplasties for macrocephaly at an average age of 17.9 months (range, 6 to 53 months) and were followed for an average of 41.5 months. The mean operative time was 4.9 hours (range, 4.3 to 6.5 hours), estimated blood loss was 530 ml (range, 200 to 1500 ml), and 78 percent received blood transfusions. The average length of hospitalization was 2.6 days. Three patients experienced complications, including one shunt revision. The mean functional assessment scores increased from 2.3 to 3.9 (p = 0.022), with all patients able to support their heads postoperatively. CONCLUSIONS: Use of a limited cranioplasty technique was associated with a hospitalization that was over 7 days shorter than has been reported in the literature for total cranial vault reductions and with a much lower shunt revision rate. Measurable improvements in motor function and subjective benefits in appearance were noted, despite a more limited reduction. Surgeons faced with this unusual condition may wish to consider performing this smaller procedure.

Melanotic neuroectodermal tumor of infancy: report of one calvarial lesion with T1 shortening and one maxillary lesion.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare tumor which commonly involves the mandible, maxilla and calvarium. We report two infants with this rare tumor. T1 shortening due to melanin content has been rarely described in MNTI. The calvarial MNTI showed T1 shortening which was helpful in diagnosis.

Giant dural venous sinus ectasia in neonates.

In this report, the authors describe 4 recent cases of posterior giant dural venous sinus ectasia in neonates diagnosed during pregnancy and encountered at 3 different institutions. Posterior giant venous sinus ectasia was diagnosed in 4 patients using antenatal ultrasonography and confirmed in 2 patients using prenatal MR imaging and in 3 patients using postnatal MR angiography. In 2 children angiography was performed at the age of 6 months. The pregnancy was terminated in 1 case, and the fetus underwent an autopsy. The 3 children who were born presented with various degree of cardiac insufficiency and were admitted to the intensive care unit after birth. Signs of increased intracranial pressure were present immediately after birth, including a bulging fontanel. No endovascular treatment was used in these cases. Surgery was performed in 2 cases as an attempt to alleviate increased intracranial pressure symptoms, without any real benefit. A slow venous flow in the ectasia was shown by ultrasonography in the case in which the pregnancy was terminated. Angiography or MR angiography did not show an obvious arteriovenous malformation in any of the cases, but an arteriovenous fistula secondary or contributing to the formation of the venous ectasia is one of the physiopathological hypotheses of the cause of this condition. Interestingly, spontaneous progressive thrombosis and regression of the intravascular component of the venous sinus ectasia was observed in all cases. The clinical outcome was acceptable in 1 child (who had a moderate handicap after the surgery) and good for the other 2 children (who had normal neurological development). Stratified thrombi of different ages are found in these giant venous ectasias and develop within the leaves of the dura close to the confluence of the major posterior venous sinuses. Therefore, it appears that the formation of a progressive thrombosis represents the normal evolution of these giant dural venous sinus ectasias, which explains the favorable outcome in some cases without specific surgical treatment, except for resuscitation techniques.

Predictors of tumor progression among children with gangliogliomas. Clinical article.

OBJECT: Few reports describe the outcome and prognostic factors for children with gangliogliomas. The objective of this report was to describe the progression-free survival (PFS) for children with low-grade gangliogliomas and identify risk factors for tumor progression. METHODS: A retrospective study was performed in children with low-grade gangliogliomas who were evaluated and treated in the neuro-oncology department between 1986 and 2006 to determine risk factors for subsequent tumor progression. RESULTS: A total of 38 children with newly diagnosed gangliogliomas were included in this report. Thirty-four children were treated with surgery alone, 3 with subtotal resection and radiation therapy, and 1 with subtotal resection and chemotherapy. The follow-up ranged from 4 months to 15.8 years (mean 5.7+/-4.2 years [+/-SD]). Seven children have experienced tumor progression, and 1 child died after his tumor subsequently underwent malignant transformation. The 5-year PFS was calculated to be 81.2% using Kaplan-Meier survival analysis. Initial presentation with seizures (p=0.004), tumor location in the cerebral hemisphere (p=0.020), and complete tumor resection (p=0.035) were associated with prolonged PFS. Further analysis of the above significant variables by a Cox regression model identified initial presentation with seizures as being associated with prolonged PFS (p=0.028). CONCLUSIONS: The PFS and overall survival of children with gangliogliomas are good. Tumors located in the cerebral hemispheres, the achievement of total resection, and seizures at presentation were associated with prolonged PFS. Cox regression analysis identified presenting symptoms including seizures as significant predictive factors of PFS. Prospective studies with larger numbers of children are needed to define the significant factors of tumor progression.