Cerebral Reorganization after Hemispherectomy: A DTI Study

BACKGROUND AND PURPOSE

Hemispherectomy is a neurosurgical procedure to treat children with intractable seizures. Postsurgical improvement of cognitive and behavioral functions is observed in children after hemispherectomy suggesting plastic reorganization of the brain. Our aim was to characterize changes in DTI scalars in WM tracts of the remaining hemisphere in children after hemispherectomy, assess the associations between WM DTI scalars and age at the operation and time since the operation, and evaluate the changes in GM fractional anisotropy values in patients compared with controls.

MATERIALS AND METHODS

Patients with congenital or acquired neurologic diseases who required hemispherectomy and had high-quality postsurgical DTI data available were included in this study. Atlas- and voxel-based analyses of DTI raw data of the remaining hemisphere were performed. Fractional anisotropy and mean, axial, and radial diffusivity values were calculated for WM and GM regions. A linear regression model was used for correlation between DTI scalars and age at and time since the operation.

RESULTS

Nineteen patients after hemispherectomy and 21 controls were included. In patients, a decrease in fractional anisotropy and axial diffusivity values and an increase in mean diffusivity and radial diffusivity values of WM regions were observed compared with controls (P < .05, corrected for multiple comparisons). In patients with acquired pathologies, time since the operation had a significant positive correlation with white matter fractional anisotropy values. In all patients, an increase in cortical GM fractional anisotropy values was found compared with controls (P < .05).

CONCLUSIONS

Changes in DTI metrics likely reflect Wallerian and/or transneuronal degeneration of the WM tracts within the remaining hemisphere. In patients with acquired pathologies, postsurgical fractional anisotropy values correlated positively with elapsed time since the operation, suggesting a higher ability to recover compared with patients with congenital pathologies leading to hemispherectomy.

Evaluating extent of resection in pediatric glioblastoma: a multiple propensity score-adjusted population-based analysis

PURPOSE

The benefit of radical resections for glioblastoma patients remains a source of contention in the literature. Few studies have been conducted in pediatric patients, and it is becoming increasingly evident that data regarding adult glioblastoma (GB) patients cannot be generalized to pediatric patients affected by this neoplasm. A comparative effectiveness study is performed for different extent of resection (EOR) groups in the largest cohort of pediatric GB (pGB) patients.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) cancer registry was used to identify pGB patients from 1988 through 2009. Multivariate- and multiple propensity score (mPS)-adjusted analyses were used to determine the effect of gross total resection (GTR), partial resection (PR), and biopsy (Bx) on overall survival. Survival prospects were summarized using direct adjusted survival curves.

RESULTS

A total of 342 pGB patients were identified, and 35.4 % of patients received a GTR, 28.8 % PR, 17.3 % Bx, and 17.0 % did not undergo surgery. In our cohort, a median overall survival of 12 months was observed with 1-, 2-, and 5-year survival rates of 51.7, 28.3, and 15.7 %, respectively. EOR was a predictor of survival in both the multivariate- (P < 0.001) and mPS-adjusted model (P < 0.001). Compared to the GTR group, a higher mortality rate was observed in patients who underwent a PR (HR 1.50; 95 % CI, 1.02-2.21) or Bx (HR 1.87; 95 % CI, 1.18-2.98). There were no significant differences in (adjusted) mortality risk between the PR and Bx groups.

CONCLUSION

Our study suggests that GTR is independently associated with improved survival for pediatric patients with glioblastoma.

Improvement of syrinx resolution after tonsillar cautery in pediatric patients with Chiari Type I malformation

OBJECT Chiari Type I malformation involves caudal displacement of the cerebellar tonsils below the foramen magnum, which obstructs normal cerebrospinal fluid flow and increases intracranial pressure. Certain aspects of its surgical treatment remain controversial. A retrospective study was conducted to assess the efficacy of tonsillar cautery on syrinx resolution among pediatric Chiari patients undergoing cervicomedullary decompression. METHODS A retrospective cohort study was performed for patients 0-18 years of age who underwent surgical correction for Chiari Type I malformation with syrinx between 1995 and 2013. Basic demographic information was collected as well as data for preoperative symptoms, prior surgical history, perioperative characteristics, and postsurgical outcomes. Descriptive statistics were performed in addition to bivariate analyses. Candidate predictor variables were identified based on an association with tonsillar cautery with p < 0.10. Forward stepwise likelihood ratio was used to select candidate predictors in a binary logistic regression model (P_in = 0.05, P_out = 0.10) most strongly associated with the outcome. RESULTS A total of 171 patients with Chiari Type I malformation with syrinx were identified, and 43 underwent tonsillar cautery. Patients who underwent tonsillar cautery had 6.11 times greater odds of improvement in their syrinx (95% CI 2.57-14.49, p < 0.001). There was no effect of tonsillar cautery on increased perioperative complications as well as the need for repeat decompressions. CONCLUSIONS Tonsillar cautery is safe and effective in the treatment of Chiari Type I malformation with syrinx and may decrease time to syrinx resolution after cervicomedullary decompression. Tonsillar cautery does not increase postoperative complications in pediatric Chiari Type I malformation patients.

Local delivery methods of therapeutic agents in the treatment of diffuse intrinsic brainstem gliomas

Brainstem gliomas comprise 10-20% of all pediatric central nervous system (CNS) tumors and diffuse intrinsic pontine gliomas (DIPGs) account for the majority of these lesions. DIPG is a rapidly progressive disease with almost universally fatal outcomes and a median survival less than 12 months. Current standard-of-care treatment for DIPG includes radiation therapy, but its long-term survival effects are still under debate. Clinical trials investigating the efficacy of systemic administration of various therapeutic agents have been associated with disappointing outcomes. Recent efforts have focused on improvements in chemotherapeutic agents employed and in methods of localized and targeted drug delivery. This review provides an update on current preclinical and clinical studies investigating treatment options for brainstem gliomas.

Shunt revision requirements after posthemorrhagic hydrocephalus of prematurity: insight into the time course of shunt dependency

PURPOSE

Intraventricular hemorrhage (IVH) is a common affliction of preterm infants and often results in posthemorrhagic hydrocephalus (PHH). These patients typically eventually require permanent CSF diversion and are presumed to be indefinitely shunt-dependent. To date, however, there has been no study of long-term shunt revision requirements in patients with PHH.

METHODS

We analyzed retrospectively collected data for 89 preterm patients diagnosed with grades III and IV IVH and PHH at our institution from 1998 to 2011.

RESULTS

Sixty-nine out of 89 patients (77.5%) underwent ventriculoperitoneal (VP) shunt placement, and 33 (47.8%) required at least one shunt revision and 18 (26.1%) required multiple revisions. The mean ± standard deviation follow-up time for shunted patients was 5.0 ± 3.3 years. The majority of early failures were due to proximal catheter malfunction, while later failures were mostly due to distal catheter problems. There was a significant difference in the number of patients requiring revisions in the first 3 years following initial VP shunt insertion compared after 3 years, with 28 revisions versus 10 (p < 0.004). In 8 out of 10 patients who underwent shunt revisions after 3 years, evidence of obstructive hydrocephalus was found on imaging either in the form of an isolated fourth ventricular cyst or aqueductal stenosis.

CONCLUSIONS

Our results suggest that in a distinct subset of patients with PHH, obstructive hydrocephalus may develop, resulting in long-term dependence on CSF diversion. Further study on the factors associated with long-term shunt dependence and revision requirements within the PHH group is warranted.

Pediatric skull fracture diagnosis: should 3D CT reconstructions be added as routine imaging?

OBJECT

The authors compared the efficacy of combining 2D+3D CT reconstructions with standard 2D CT images in the diagnosis of linear skull fractures in children with head trauma.

METHODS

This was a retrospective evaluation of consecutive head CT studies of children presenting with head trauma. Two experienced pediatric neuroradiologists in consensus created the standard of reference. Three readers independently evaluated the 2D CT images alone and then in combination with the 3D reconstructions for the diagnosis of linear skull fractures. Sensitivity and specificity in the diagnosis of linear skull fractures utilizing 2D and 2D+3D CT in combination were measured for children less than 2 years of age and for all children for analysis by the 3 readers.

RESULTS

Included in the study were 250 consecutive CT studies of 250 patients (167 boys and 83 girls). The mean age of the children was 7.82 years (range 4 days to 17.4 years). 2D+3D CT combined had a higher sensitivity and specificity (83.9% and 97.1%, respectively) compared with 2D alone (78.2% and 92.8%, respectively) with statistical significance for specificity (p < 0.05) in children less than 2 years of age. 2D+3D CT combined had a higher sensitivity and specificity (81.3% and 90.5%, respectively) compared with 2D alone (74.5% and 89.1%, respectively) with statistical significance for sensitivity (p < 0.05) in all children.

CONCLUSIONS

In this study, 2D+3D CT in combination showed increased sensitivity in the diagnosis of linear skull fractures in all children and increased specificity in children less than 2 years of age. In children less than 2 years of age, added confidence in the interpretation of fractures by distinguishing them from sutures may have a significant implication in the setting of nonaccidental trauma. Furthermore, 3D CT is available at no added cost, scan time, or radiation exposure, providing trainees and clinicians with limited experience an additional valuable tool for routine imaging of pediatric head trauma.

Challenges in early operative approaches to intramedullary spinal cord tumors: Harvey Cushing’s perspective

Although Harvey Cushing was mostly known for his contributions to brain tumor surgery, he was also a pioneer in the development of spinal cord surgery. This lesser known facet of Cushing’s career can provide a fresh and unique perspective into how the founders of neurosurgery surmounted early challenges in the field. The authors bring to light and examine for the first time Cushing’s unpublished writing “Technique of Laminectomy” along with his first 3 documented intramedullary spinal cord tumor (IMSCT) cases at the Johns Hopkins Hospital. The authors draw lessons from the challenges in pathological classification, preoperative diagnosis, tumor localization, and surgical technique ofthat time. Although Cushing’s attempts at exploration and resection of IMSCT as described here were of limited success, his ability to adapt his clinical and surgical technique to the challenges of the time, as well as develop skills to successfully manipulate the spinal cord during these exploratory procedures without the patients incurring neurological damage, postoperative infection, or complications, is a testament to his determination to advance the field and his meticulous operative technique. In spite of the limitations imposed on the pioneer neurosurgeons, Harvey Cushing and his contemporaries persevered through many of the challenges and built an essential part of neurosurgery’s common story.

Primary Ewing sarcoma of the cavernous sinus

INTRODUCTION

Ewing sarcoma (ES) is a part of a larger family of round blue-cell tumors that occasionally manifest as osseous or extraosseous lesions adjacent to or within the central nervous system (CNS). Although a large body of literature exists on ES of bone, data are lacking on tumors with cranial or spinal components that affect the CNS. Moreover, primary intracranial ES has been uncommonly reported, and its location in the cavernous sinus is extremely rare, with only a few cases reported in literature.

METHOD

We describe a case of a 15-year-old boy who presented initially with a seizure along with acute abducens, trochlear, and oculomotor nerve pareses. Magnetic resonance imaging (MRI) revealed a cavernous sinus mass. Given the rapid growth and aggressive nature of the mass, a biopsy of the lesion was performed. Microscopic examination of the specimen showed immunohistological features consistent with ES. The patient was treated with multi-agent chemotherapy and fractionated radiation therapy.

RESULT

Clinical assessment 7 months after completion of chemotherapy and 4 months after completion of radiotherapy revealed that the patient's ocular motility and alignment had improved significantly, and MRI showed almost complete disappearance of the tumor.

CONCLUSION

This is one of only six cases of extraosseous primary intracranial ES of the cavernous sinus reported in literature to date. The availability of multi-agent chemotherapy and fractionated radiation therapy in this patient resulted in his marked clinical and imaging improvement. It remains to be seen if this therapy will result in long-term control or cure of the lesion in our patient. In the meantime, increasing awareness and identification of children primary intracranial ES will hopefully allow a better understanding of the molecular biology of this tumor and the development of standardized treatment regimens.

Poor prognosis despite aggressive treatment in adults with intramedullary spinal cord glioblastoma

We report our institution's experience with adult patients who underwent surgery for intramedullary spinal cord glioblastoma. Spine involvement of glioblastoma is rare, representing 7.5% of all intramedullary gliomas and 1-3% of all spinal cord tumors. We performed a retrospective review of five male patients with intramedullary spinal cord glioblastoma who underwent surgical resection from 1990 to 2014. Demographic, operative, and postoperative factors were recorded. The median age at treatment was 31 years (range: 18-61) and all men presented with motor or sensory dysfunction. Two had prior surgical resection of an intramedullary World Health Organization Grade III anaplastic astrocytoma lesion with adjuvant chemoradiation. All tumors were present in the cervical (n=2; 40%) or thoracic (n=3; 60%) spine, spanning a median of three levels (range: 2-4). Gross total resection was achieved in three men (60%), and there were no intraoperative mortalities or complications. Although one had improvement in his neurological status postoperatively, all five men died with a median time to death of 20 months (range: 2-31). Adult intramedullary spinal cord glioblastoma is rare, and despite aggressive treatment, prognosis is poor, with a median survival in our series of only 20 months. New treatment strategies are necessary to improve survival in this patient population.

Spinal decompression in achondroplastic patients using high-speed drill versus ultrasonic bone curette: technical note and outcomes in 30 cases

BACKGROUND

This manuscript describes the clinical and operative characteristics of achondroplastic children who undergo multilevel thoracolumbar decompressions using either the high-speed drill or the ultrasonic bone curette (BoneScalpel).

METHODS

We retrospectively reviewed 30 thoracolumbar decompressions in achondroplastic patients at a single institution between 2008 and 2013. Patients were classified into either the high-speed drill cohort or the BoneScalpel cohort, depending on which instrument was utilized to perform the decompression. A technical note on the role of the ultrasonic bone curette in decompressing stenotic achondroplastic spines is also provided.

RESULTS

In comparison with the high-speed drill cohort, the BoneScalpel cohort experienced less overall perioperative complications, including durotomy, cerebrospinal fluid leak, pseudomeningoceles, wound infection, and wound dehiscence. Although 45.0% of patients experienced a durotomy in the high-speed drill cohort, only 30.0% of patients experienced a durotomy in the BoneScalpel cohort (P = 0.694). In the high-speed drill cohort, the number of patients complaining of sensory disturbances, back pain, ataxia, incontinence, neurogenic claudication, radiculopathy, ataxia, and/or weakness decreased postoperatively. Similar results were observed in the BoneScalpel cohort.

CONCLUSIONS

Although spinal decompression provides symptomatic resolution in patients with achondroplasia, intraoperative complications, in general, and durotomies, in particular, are common. Here, we report a decreased incidence in intraoperative durotomy and overall perioperative complication rates in the BoneScalpel cohort, although this did not reach the level of statistical significance. Nonetheless, the data demonstrate that the BoneScalpel is a safe and efficacious alternative to the high-speed drill in these challenging patients.

LEVEL OF EVIDENCE

Level II-retrospective study.

Ventricular reservoir versus ventriculosubgaleal shunt for posthemorrhagic hydrocephalus in preterm infants: infection risks and ventriculoperitoneal shunt rate

OBJECT

The most common neurosurgical condition observed in preterm infants is intraventricular hemorrhage (IVH), which often results in posthemorrhagic hydrocephalus (PHH). These conditions portend an unfavorable prognosis; therefore, the potential for poor neurodevelopmental outcomes necessitates a better understanding of the comparative effectiveness of 2 temporary devices commonly used before the permanent insertion of a ventriculoperitoneal (VP) shunt: the ventricular reservoir and the ventriculosubgaleal shunt (VSGS).

METHODS

The authors analyzed retrospectively collected information for 90 patients with IVH and PHH who were treated with insertion of a ventricular reservoir (n = 44) or VSGS (n = 46) at their institution over a 14-year period.

RESULTS

The mean gestational age and weight at device insertion were lower for VSGS patients (30.1 ± 1.9 weeks, 1.12 ± 0.31 kg) than for reservoir patients (31.8 ± 2.9 weeks, 1.33 ± 0.37 kg; p = 0.002 and p = 0.004, respectively). Ventricular reservoir insertion was predictive of more CSF taps prior to VP shunt placement compared with VSGS placement (10 ± 8.7 taps vs 1.6 ± 1.7 taps, p < 0.001). VSGS patients experienced a longer time interval prior to VP shunt placement than reservoir patients (80.8 ± 67.5 days vs 48.8 ± 26.4 days, p = 0.012), which corresponded to VSGS patients gaining more weight by the time of shunt placement than reservoir patients (3.31 ± 2.0 kg vs 2.42 ± 0.63 kg, p = 0.016). Reservoir patients demonstrated a trend toward more positive CSF cultures compared with VSGS patients (n = 9 [20.5%] vs n = 5 [10.9%], p = 0.21). There were no significant differences in the rates of overt device infection requiring removal (reservoir, 6.8%; VSGS, 6.5%), VP shunt insertion (reservoir, 77.3%; VSGS, 76.1%), or early VP shunt infection (reservoir, 11.4%; VSGS, 13.0%) between the 2 cohorts.

CONCLUSIONS

Although the rates of VP shunt requirement and device infection were similar between patients treated with the reservoir versus the VSGS, VSGS patients were significantly older and had achieved greater weights at the time of VP shunt insertion. The authors' results suggest that the VSGS requires less labor-intensive management by ventricular tapping; the VSGS patients also attained higher weights and more optimal surgical candidacy at the time of VP shunt insertion. The potential differences in long-term developmental and neurological outcomes between VSGS and reservoir placement warrant further study.

Evaluation of complication rates of pediatric cranial procedures in which a polyethylene glycol sealant was used

OBJECT

Polyethylene glycol (PEG) sealant in conjunction with standard closure techniques is effective in preventing CSF leaks after cranial procedures in adult patients, but the safety of PEG sealant in the pediatric population has not been shown.

METHODS

The authors performed a retrospective analysis of pediatric neurosurgery patients (0-18 years of age) treated from 2005 to 2010 at The Johns Hopkins Hospital. There were 163 patients who underwent cranial surgery with the use of PEG sealant as an adjunct to standard closure techniques. There were 92 males and 71 females with an average age of 10.2 years. The incidences of revision surgery, CSF leak, meningitis, and neurological deficit were recorded.

RESULTS

In the cohort's 90-day postoperative clinical course, the authors found that 4 patients (2.5%) required revision surgery, 2 patients (1.2%) developed a CSF leak, 4 patients (2.5%) developed a superficial skin infection, and 1 patient developed meningitis (0.6%) with no deaths or neurological deficits observed.

CONCLUSIONS

PEG sealant appears to be a safe adjunct to standard dural closure in pediatric cranial surgery patients to augment dural closure.

Diffusion tensor imaging in pediatric Chiari type I malformation

AIM

Chiari type I malformation (C1M) may be symptomatic or asymptomatic as an incidental finding. In this retrospective study, we applied diffusion tensor imaging (DTI) to study the brainstem and cerebellar white matter tracts in C1M.

METHOD

Diffusion tensor imaging (DTI) data were acquired on a 1.5T MR-scanner using balanced pairs of diffusion gradients along 20 non-collinear directions. Measurements from regions of interest in each pontine corticospinal tract, medial leminscus, and middle cerebellar peduncle (MCP) and in the lower brainstem were obtained for fractional anisotropy and mean, axial, and radial diffusivity. Values in symptomatic and asymptomatic children, and children with and without hydromyelia were compared using analysis of variance.

RESULTS

Fifteen children with C1M (10 males, five females; six symptomatic [four with hydromyelia] and nine asymptomatic) were included. Median age was 6 years 5 months (range 2y 10mo-15y 4mo). No significant differences in DTI scalars were found in the lower brainstem. In both MCPs, axial diffusivity values were lower in symptomatic than in asymptomatic children (p=0.049 and p=0.035 respectively) and higher in children with hydromyelia versus without hydromyelia (p=0.018 and p=0.006 respectively). In the left MCP, mean diffusivity values were lower in symptomatic than in asymptomatic children (p=0.047).

INTERPRETATION

Our results show that microstructural tissue alterations may be present in C1M. Additionally, our study suggests a specific role for the MCPs in C1M. Further large-scale studies are warranted.

Hypertrophic olivary degeneration in a child following midbrain tumor resection: longitudinal diffusion tensor imaging studies

Hypertrophic olivary degeneration (HOD) is a dynamic process caused by disruptive lesions affecting components of the Guillain-Mollaret triangle (GMT). The authors applied diffusion tensor imaging (DTI) to investigate longitudinal changes of the GMT components in a child with HOD after neurosurgery for a midbrain tumor. Diffusion tensor imaging data were acquired on a 1.5-T MRI scanner using a balanced pair of diffusion gradients along 20 noncollinear directions 1 day and 3, 6, and 9 months after surgery. Measurements from regions of interest (ROIs) were sampled in the affected inferior olivary nucleus, ipsilateral red nucleus, and contralateral superior and inferior cerebellar peduncles and dentate nucleus. For each ROI, fractional anisotropy and the mean, axial, and radial diffusivities were calculated. In the affected inferior olivary nucleus, the authors found a decrease in fractional anisotropy and an increase in mean, axial, and radial diffusivities 3 months after surgery, while 3 months later fractional anisotropy increased and diffusivities decreased. For all other GMT components, changes in DTI scalars were less pronounced, and fractional anisotropy mildly decreased over time. A detailed analysis of longitudinal DTI scalars in the various GMT components may shed light on a better understanding of the dynamic complex histopathological processes occurring in pediatric HOD over time.

Evaluation of complication rates of pediatric spinal procedures in which a polyethylene glycol sealant was used

OBJECT

Cerebrospinal fluid leakage following durotomy in spinal surgery can lead to significant patient morbidity and mortality, including meningitis and even death. Usage of a polyethylene glycol (PEG) sealant in combination with standard closure techniques has been shown to be effective in preventing CSF leaks in animal models and adult patients, but the results of its use have not been reported in the pediatric population.

METHODS

A retrospective analysis was performed of pediatric neurosurgery patients (0-18 years of age) treated at The Johns Hopkins Hospital from 2003 to 2010. There were 93 spinal surgery patients identified in whom PEG was applied. The incidence of CSF leakage, meningitis, and neurological injury was recorded. There were 54 males and 39 females in this study with an average age of 8.7 years. Of the identified patients, 16.1%, 28%, and 55.9% underwent surgery in the cervical region, thoracic region, and lumbar region, respectively.

RESULTS

At 90-day follow-up, 5 patients (5.4%) had a CSF leak, 4 patients (4.3%) required a reoperation, and 1 patient (1.1%) had meningitis within this time period. No deaths or associated neurological deficits were observed.

CONCLUSIONS

The use of a PEG sealant to augment dural closure in pediatric spine surgery appears to be a safe adjunct to standard dural closure in pediatric spine patients.

Thermal latency studies in opiate-treated mice

Background:

The change in the reaction time of a tail or paw exposed to a thermal stimulus is a measure of nociceptive activity in laboratory animals. Tail-flick and plantar thermal sensitivity (Hargreaves) tests are non-invasive, minimize stress, and can be used to screen animals for phenotype and drug activity.

Objective:

Hargreaves testing has been widely used in rats. We investigated its use to measure the activity of opiate analgesia in mice.

Methods:

Mice were used in thermal stimulus studies at 1-5 hours and 1-5 days to test acute and extended release preparations of buprenorphine.

Results:

Hargreaves testing had limited value at 1-5 hours because mice can have an obtunded response to opiate therapy. Tail-flick studies with restrained mice are not affected by the initial locomotor stimulation.

Discussion:

The present report describes a simple restraint system for mice. The utility of the system is demonstrated by examining the efficacy of acute and extended release buprenorphine injections in Balb/c and Swiss mice.

Conclusion:

Standardized tail-flick testing provides a sensitive robust method to monitor opiate activity in mice.

Complications and subsequent removal of retained shunt hardware after endoscopic third ventriculostomy: case series

This case series highlights multiple complications and subsequent removal of retained shunt hardware in pediatric patients after successful endoscopic third ventriculostomy (ETV). Removal or retention of existing shunt hardware following ETV represents an important dilemma. Prior studies have reported infections and organ perforation related to nonfunctioning shunts but none in the context of successful ETV. Data obtained in 3 children with hydrocephalus treated at the authors' institution were retrospectively reviewed after the patients experienced complications due to retained shunt hardware following ETV. Etiologies of hydrocephalus included tectal glioma and intraventricular hemorrhage. All 3 patients had a history of multiple shunt revisions and underwent urgent ETV in the setting of a shunt malfunction. In each case, the entire shunt system was left in situ, but it became the source of subsequent complications. Two of the 3 patients presented with the shunt infected by gram-negative bacilli 10 days and 4.5 months postoperatively, respectively. The remaining patient experienced wound dehiscence over the shunt valve 4.5 months after ETV. In all patients, the complications were managed successfully by removing the shunt hardware. None of the patients required repeat shunt insertion from the time of removal throughout the follow-up period (mean 24 months, range 9-36 months). During the study period, a total of 6 patients with indwelling shunt hardware underwent ETV with the expectation of being shunt independent. Among these 6 patients, 3 experienced no complications from the retained hardware whereas 3 patients (50%) ultimately experienced adverse consequences related to retained hardware. This case series illustrates complications involving retained shunt hardware after successful ETV. These examples support consideration of shunt removal at the time of ETV in the appropriate context.

The periumbilical approach in ventriculoperitoneal shunt placement: technique and long-term results

OBJECT

The aim of this study was to examine the feasibility and safety of ventriculoperitoneal (VP) shunt placement using a periumbilical approach for distal peritoneal access. By using this minimally invasive approach, the authors hypothesized that the cosmetic outcomes would be better than could be achieved by using a traditional minilaparotomy and that clinical results would be comparable.

METHODS

A periumbilical approach was used for distal catheter insertion during a first-time VP shunt placement in 20 patients (8 males and 12 females). Median age at time of surgery was 3.0 months (range 7 days-11.9 years) and mean follow-up time was 17.8 months (range 1.2-28.0 months). The median weight of the patients was 3.99 kg (range 1.95-57.0 kg). A single incision was made along the natural crease inferior to the umbilicus. The linea alba was exposed and a 1-mm incision made while the patient was temporarily held in a Valsalva maneuver. A peritoneal trocar was then inserted through the fascial incision and the distal catheter was passed into the peritoneal space.

RESULTS

The incision line in all patients healed well, did not require operative revision, and was described as minimally visible by the patients' families. Mean operative time was 35 minutes. Eight patients required revision surgery. One distal failure occurred when the distal shunt tubing retracted and became coiled in the neck; this was repaired by conversion to a minilaparotomy for distal replacement. There was 1 shunt infection (5%) requiring shunt removal and replacement. One patient had significant skin thinning around the valve and proximal catheter, which required replacement of the entire shunt system, and another patient underwent a conversion to a ventriculoatrial shunt due to poor peritoneal absorption. In the remaining 4 patients who required operative revision, the peritoneal portion of the shunt was not involved.

CONCLUSIONS

The periumbilical approach for peritoneal access during VP shunt placement is technically feasible, has low infection rates, and has cosmetically appealing results. It may be considered as an alternative option to standard VP shunt placement techniques.

Pediatric spinal tumors

Although tumors of the central nervous system in children constitute the second most prevalent tumor type of childhood, spinal cord tumors account for less than 10% of pediatric central nervous system tumors. The most common are intramedullary, although they can be found in the extradural compartment or as intradural extramedullary masses. Extradural tumors can arise from bony elements, the meninges, or soft tissues. Neuroblastomas and sarcomas are frequently encountered along with bone tumors. Intradural extramedullary tumors can be meningeal or from distant sites and include meningiomas and schwannomas; most tend to be benign. Intradural intramedullary tumors, neuronal or glial, can be derived from neuroepithelial tissues. For the intramedullary tumors, astrocytomas represent around 60% of tumors, ependymomas 30%, and developmental tumors 4%. Such tumors require a multidisciplinary approach to ensure optimal patient outcomes. Spinal cord tumors most often present with pain followed by motor regression, gait disturbance, sphincter dysfunction or sensory loss, torticollis, and kyphoscoliosis. Treatment is based on tumor type, but surgical resection is the mainstay. Predictors of outcome include the histological grading, extent of resection, and neurological status at the time of surgery.

Ultrasonic BoneScalpel for Osteoplastic Laminoplasty in the Resection of Intradural Spinal Pathology: Case Series and Technical Note

BACKGROUND:

Osteoplastic laminoplasty is a well-described technique that may decrease the incidence of progressive kyphosis when used in the setting of intradural spinal cord tumor resection.

OBJECTIVE:

The BoneScalpel by Aesculap (Central Valley, Pennsylvania) is an ultrasonic osteotome that precisely cuts bone while preserving the underlying soft tissues, potentially reducing the risk of dural laceration during laminoplasty. By producing osteotomies as narrow as 0.5 mm, the device may also facilitate postoperative osteointegration.

METHODS:

A retrospective analysis was conducted of 40 patients (mean age, 38.0 years; range, 4.0-79.7 years) who underwent osteoplastic laminoplasty using the BoneScalpel for the treatment of intradural spinal pathology at the Johns Hopkins Hospital between January 2009 and December 2011. After lesion resection, titanium plates were used to reconstruct the lamina in all cases. The technical results and procedure-related complications were subsequently noted.

RESULTS:

Successful laminoplasty was carried out in all 40 patients. Intraoperatively, 1 case of incidental durotomy was noted after use of the device, which was repaired primarily without neurological or clinical sequelae. During the follow-up period (mean, 195 days; median, 144 days), there were 2 complications (1 cerebrospinal fluid leak, 1 seroma) and no cases of immediate postoperative instability.

CONCLUSION:

The BoneScalpel is a safe and technically feasible device for performing osteoplastic laminoplasty.

Treatment of choroid plexus tumors: a 20-year single institutional experience

OBJECT

Choroid plexus tumors (CPTs) are rare intracranial neoplasms that constitute approximately 2%-5% of all pediatric brain tumors. Most of these tumors present with severe hydrocephalus. The optimal perioperative management and oncological care remain a matter of debate. The authors present the epidemiological and clinical features of CPTs from a 20-year single-institutional experience.

METHODS

A total of 39 consecutive patients with pathologically proven CPTs (31 choroid plexus papillomas [CPPs] and 8 choroid plexus carcinomas [CPCs]) were included in this series. Patient demographics, clinical presentation, comorbidities, indications for surgery, radiological studies, tumor location, and all operative variables were reviewed for each case. Multivariate regression analysis was performed to identify independent predictors of tumor recurrence and survival.

RESULTS

The overall mean age (± SD) was 13.13 ± 19.59 years (15.27 ± 21.10 years in the CPP group and 3.66 ± 3.59 years in the CPC group). Hydrocephalus was noted at presentation in 34% of patients. The most common presenting symptoms were headache (32%) and nausea/vomiting (26%). Gross-total resection (GTR) was achieved in 86% of CPPs and in 71% of CPCs (p = 0.57). There was 100% survival in patients with CPPs observed at the 5- and 10-year follow-up and 71% survival in patients with CPCs at the 5-year follow-up. In a multivariate regression analysis, a diagnosis of papilloma, preoperative vision changes, or hydrocephalus; right ventricle tumor location; and GTR were all independently associated with a decreased likelihood of tumor recurrence at last follow-up.

CONCLUSIONS

The authors' study suggests that patients with CPCs are more likely to experience local recurrence and metastasis; hence, GTR with chemotherapy and radiotherapy, particularly for CPCs, is pivotal in preventing recurrence and prolonging survival. While GTR was important for local control following resection of CPPs, it had a minimal effect on prolonging survival in this patient cohort.