Cormac O. Maher
Cormac O. Maher
Kévin Beccaria, Michael Canney, Guillaume Bouchoux, Stéphanie Puget, Jacques Grill, and Alexandre Carpentier
Pediatric brain tumors are the most common solid tumor and the first cause of cancer death in childhood, adolescence, and young adulthood. Current treatments are far from optimal in most of these tumors and the prognosis remains dismal for many of them. One of the main causes of the failure of current medical treatments is in part due to the existence of the blood-brain barrier (BBB), which limits drug delivery to tumors. Opening of the BBB with low-intensity pulsed ultrasound (LIPU) has emerged during the last 2 decades as a promising technique for enhancing drug delivery to the brain. In preclinical models, enhanced delivery of a wide range of therapeutic agents, from low-molecular-weight drugs, to antibodies and immune cells, has been observed as well as tumor control and increased survival. This technique has recently entered clinical trials with extracranial and intracranial devices. The safety and feasibility of this technique has furthermore been shown in patients treated monthly for recurrent glioblastoma receiving carboplatin chemotherapy. In this review, the characteristics of the BBB in the most common pediatric brain tumors are reviewed. Then, principles and mechanisms of BBB disruption with ultrasound (US) are summarized and described at the histological and biological levels. Lastly, preclinical studies that have used US-induced BBB opening in tumor models, recent clinical trials, and the potential use of this technology in pediatrics are provided.
Ulrich-Wilhelm Thomale and Matthias Schulz
Anne Morice, Frédéric Kolb, Arnaud Picard, Natacha Kadlub, and Stéphanie Puget
Reconstruction of complex skull defects requires collaboration between neurosurgeons and plastic surgeons to choose the most appropriate procedure, especially in growing children. The authors describe herein the reconstruction of an extensive traumatic bone and soft tissue defect of the cranial vault in an 11-year-old boy. The size of the defect, quality of the tissues, and patient's initial condition required a 2-stage approach. Ten months after an initial emergency procedure in which lacerated bone and soft tissue were excised, reconstruction was performed. The bone defect, situated on the left frontoparietal region, was 85 cm2 and was filled by a custom-made porous hydroxyapatite implant. The quality of the overlying soft tissue did not allow the use of classic local and locoregional coverage techniques. A free latissimus dorsi muscle flap branched on the contralateral superficial temporal pedicle was used and left for secondary healing to take advantage of scar retraction and to minimize alopecia. Stable well-vascularized implant coverage as well as an esthetically pleasing skull shape was achieved. Results in this case suggest that concomitant reconstruction of large calvarial defects by cranioplasty with a custom-made hydroxyapatite implant covered by a free latissimus dorsi muscle flap is a safe and efficient procedure in children, provided that there is no underlying infection of the operative site.
Anne Morice, Sylvie Fraitag, Catherine Miquel, Christian Sainte Rose, and Stéphanie Puget
Juvenile xanthogranuloma (JXG) is a rare disease that belongs to the non-Langerhans cell histiocytoses. It presents a wide clinical spectrum, usually occurs before 5 years of age, and is commonly confined to the skin; however, it can affect multiple sites, including the nervous system, and can lead to severe disorders. Although JXG is a benign disease that usually regresses spontaneously, several curative treatments have been proposed in cases of organ involvement. Treatment options include corticosteroids, chemotherapy, and radiotherapy; however, these can have severe, long-term adverse effects in children.
The authors here describe the first case of spontaneous resolution of an intramedullary spinal cord lesion of JXG associated with cerebral and cutaneous lesions in a young boy with 9 years of follow-up. The initial neurological symptoms resolved without any surgical or medical treatment. This case shows that extracutaneous lesions of JXG, including those with intramedullary spinal cord involvement, can regress without curative treatment—like cutaneous lesions—although both multidisciplinary care and close follow-up should be implemented.
Pierre-Aurelien Beuriat, Stephanie Puget, Giuseppe Cinalli, Thomas Blauwblomme, Kevin Beccaria, Michel Zerah, and Christian Sainte-Rose
Hydrocephalus remains one of the more common pathologies managed in pediatric neurosurgical units. Endoscopic third ventriculostomy (ETV) has an advantage over ventriculoperitoneal shunting as it enables patients to remain device free. Multiple shunt devices with various valve designs exist, with no one valve proven to be superior to another. The aim of this study was to describe the management of hydrocephalus and its long-term outcome.
The authors retrospectively reviewed the medical records of all patients who had been treated for hydrocephalus at the Hôpital Necker-Enfants Malades in the period from 1985 to 1995.
Nine hundred seventy-five children had been treated for hydrocephalus. The mean follow-up was 11 ± 7.4 years (mean ± standard deviation). The most common cause of hydrocephalus was tumor related (32.3%), followed by malformative (24.5%) and inflammatory (20.9%) causes. Two hundred eighty patients underwent ETV as the first-line treatment. The procedure was effective in controlling hydrocephalus due to posterior fossa tumors and aqueductal stenosis. Six hundred ninety-five children had initial shunt insertion, with the majority receiving an Orbis-Sigma valve (OSV). The overall OSV shunt survival was 70% at 1 year, 58% at 10 years, and 49% at 20 years. The most common cause for mechanical shunt failure was obstruction (50.7%). Overall shunt survival was statistically different between the OSV and the differential-pressure valve (p = 0.009).
Endoscopic third ventriculostomy is effective in the management of childhood hydrocephalus. Its success is directly related to the underlying pathology. In the long term, the OSV has significantly higher event-free shunt survival than the classic differential-pressure valve systems
Senta Kurschel, Stéphanie Puget, Marie Bourgeois, Michel Zerah, Petra Ofner, and Dominique Renier
In this study the authors' goal was to identify the complication rate of subduroperitoneal (SDP) shunts for the treatment of subdural hematomas (SDHs) in infants and to determine the influences on and predictive factors for these complications.
The authors present a case series spanning the years 1994 to 2003 and include a statistical analysis of 161 children 2 years of age or younger with SDH who were treated using a unilateral valveless SDP shunt. The patient history, characteristics, and treatment methods including prior therapies, neuroimaging findings, and clinical outcomes were measures of evaluation.
Thirty-six children (22.4%) suffered complications related to SDP shunts: obstruction in 27 (16.8%), infections in eight (5%), disconnection in four (2.5%), migration in three (1.9%), wound complications (leakage and skin ulceration) in two (1.2%), and symptomatic subdural rebleeding in one (0.6%) necessitating bur hole evacuation. Seventeen children (10.6%) underwent placement of a second SDP shunt because of ipsilateral or contralateral persistent fluid collections, or premature shunt removal. With the exception of 12 patients (7.4%), shunt removal was performed systematically and resulted in the following minor complications in 30 children (18.6%): an adherent proximal catheter in 16 (9.9%), transient symptoms of intracranial hypertension in six (3.7%), subcutaneous cerebrospinal fluid accumulation in four (2.5%), local infections in three (1.9%), and hydrocephalus requiring placement of a ventriculoperitoneal shunt in one (0.6%).
Status epilepticus at presentation and neuroimaging findings such as areas of hyperdensity on computed tomography (CT) scans representing fresh blood in the subdural fluid collections before shunt insertion and at follow up were predictors of shunt-related complications. Correlations were also discovered for the following CT findings: ischemic lesions before shunt treatment, cerebral atrophy and ventricular dilation during the last follow up, and residual medium to large collections before shunt removal. Children who attained a good outcome were less affected by shunt-related complications, unlike those who presented with focal deficits and/or visual impairment.
Subduroperitoneal shunt placement for the treatment of SDH in infants is—despite the complication rate—an effective and often inevitable treatment option, especially for most large and symptomatic SDHs; a certain number of complications could be reduced with careful and precise surgical techniques. Close observation for detection of risks is mandatory, and seizure control is essential to prevent further brain injury that may result in large subdural fluid collections that are difficult to treat.
Jessica Ternier, Alison Wray, Stéphanie Puget, Nathalie Bodaert, Michel Zerah, and Christian Sainte-Rose
The authors characterized the clinical course of tectal plate lesions in a group of pediatric patients to identify the prognostic factors at presentation that predict progression, in an attempt to differentiate tectal hamartomas from tumors.
A retrospective review was conducted of the management of tectal plate lesions in children since the advent of magnetic resonance (MR) imaging at the authors’ hospital (1984–2003). The lesion volume seen on MR images, the clinical and radiological features at presentation, and the clinical course of the population were analyzed for correlations.
Forty children with tectal lesions presented in the typical delayed fashion (mean 8.5 months) with symptoms referable to hydrocephalus (93%). Fourteen children whose tumors demonstrated radiological progression (enlargement, contrast enhancement, or cystic change) were treated surgically. Histologically, 80% of the surgically treated lesions were low grade (with the other 20% consisting of one dysplasia, one high-grade tumor, and one unidentified tumor). Five patients required a second operation and one required a third. One patient died of a high-grade astrocytoma after undergoing surgery and radiotherapy; the other 39 patients remain clinically stable. The only factor predictive of tumor enlargement was lesion volume at presentation (p = 0.002). Distribution analysis revealed three subgroups based on lesion volume (< 4, 4–10, and > 10 cm3), which correlated with the clinical course of the disease.
Children with tectal lesions should undergo contrast-enhanced MR imaging and volume assessment at the time of presentation. After hydrocephalus has been managed with endoscopic third ventriculostomy, these children require prolonged, close clinical and radiological surveillance. Lesions with a volume less than 4 cm3 were likely to be hamartomas and followed a predominantly benign course, with few atypical cases progressing. All large lesions, defined as having a volume greater than 10 cm3 at presentation, eventually required treatment, and all were histologically determined to be tumors. An argument is made for earlier treatment of larger lesions with the aim of improving outcome.
Aymeric Amelot, Kevin Beccaria, Thomas Blauwblomme, Marie Bourgeois, Giovanna Paternoster, Marie-Laure Cuny, Michel Zerah, Christian Sainte-Rose, and Stephanie Puget
Arachnoid cysts (ACs) are most frequently located in the middle cranial fossa. Some patients are asymptomatic whereas others exhibit signs of increased intracranial pressure, seizures, or cognitive and behavioral symptoms. When ACs do require treatment, the optimal surgical technique remains controversial. This study was conducted to assess the most effective surgical treatment for these cysts.
The authors retrospectively reviewed 240 temporal intracranial ACs managed over a 25-year period in their pediatric neurosurgical unit. Pre- and posttreatment results were clinically and radiologically assessed.
A majority of male patients (74.6%) with an overall median age of 6.9 years were included. The mean cyst size was 107 cm3; the Galassi classification showed 99 (41.3%) type I, 77 (32.1%) type II, and 64 (26.7%) type III cysts. Forty-four ACs (18.3%) were diagnosed after rupture. Surgical management was performed by microsurgery (28.3%), endoscopic cyst fenestration (14.6%), cystoperitoneal shunting (CPS; 16.2%), or subdural shunting (10%). Furthermore, 74 children (30.8%) did not undergo operations. After a mean follow-up of 4.1 years, the mean percentage decrease in cyst volume and the overall rate of clinical improvement did not significantly differ. The endoscopy group had earlier complications and a shorter event-free survival (EFS) time (EFS at 3 years = 67.7%, vs 71.5% and 90.5% for CPS and microsurgery, respectively; p < 0.007) and presented with more subdural hematomas compared to the microsurgery group (p < 0.005). The microsurgery group also showed a tendency for longer cystocisternostomy permeability than the endoscopy group.
Concerning the management of unruptured symptomatic temporal ACs, microsurgery appears to be the most effective treatment, with longer EFS and fewer complications compared to shunting or endoscopy.