Pineocytoma in a child with Pallister-Killian syndrome: a case report and review of the literature.

Pallister-Killian syndrome (PKS; OMIM #601803) is a rare genetic disorder typically characterized by developmental delay, seizures, sparse temporal hair, and facial dysmorphisms. PKS is most frequently caused by mosaic supernumerary isochromosome 12p. Here, we report a 27-month-old girl with a prenatal diagnosis of PKS and a histopathological diagnosis of pineocytoma.

Image-guided biopsy of intracranial lesions in children, with a small robotic device: a case series.

BACKGROUND AND OBJECTIVES: Robot-assisted biopsies have gained popularity in the last years. Most robotic procedures are performed with a floor-based robotic arm. Recently, Medtronic Stealth Autoguide, a miniaturized robotic arm that work together with an optical neuronavigation system, was launched. Its application in pediatric cases is relatively unexplored. In this study, we retrospectively report our experience using the Stealth Autoguide, for frameless stereotactic biopsies in pediatric patients. METHODS: Pediatric patients who underwent stereotactic biopsy using the Stealth Autoguide cranial robotic platform from July 2020 to May 2023 were included in this study. Clinical, neuroradiological, surgical, and histological data were collected and analyzed. RESULTS: Nineteen patients underwent 20 procedures (mean age was 9-year-old, range 1-17). In four patients, biopsy was part of a more complex surgical procedure (laser interstitial thermal therapy - LITT). The most common indication was diffuse intrinsic brain stem tumor, followed by diffuse supratentorial tumor. Nine procedures were performed in prone position, eight in supine position, and three in lateral position. Facial surface registration was adopted in six procedures, skull-fixed fiducials in 14. The biopsy diagnostic tissue acquisition rate was 100% in the patients who underwent only biopsy, while in the biopsy/LITT group, one case was not diagnostic. No patients developed clinically relevant postoperative complications. CONCLUSION: The Stealth Autoguide system has proven to be safe, diagnostic, and highly accurate in performing stereotactic biopsies for both supratentorial and infratentorial lesions in the pediatric population.

Jugular foramen stenosis in external hydrocephalus in infants.

OBJECTIVE: To measure the size of jugular foramina in infants affected by external hydrocephalus (EH) and in a control group, to support the hypothesis that a jugular foramen (JF) stenosis may determine dural venous sinus alterations and increased venous outflow resistance as main pathophysiological factor. METHODS: Minimum, maximum, and mean values of JF areas were measured in a series of phase-contrast magnetic resonance venous angiography (angio MRV PCA3D) performed on 81 infants affected by EH. Results were compared with a group of 54 controls. RESULTS: Smaller JF area was significantly smaller in patients versus controls (43.1 ± 14.6 vs. 52.7 ± 17.8; p < 0.001) resulting in a significantly smaller mean JF areas in patients vs. controls (51.6 ± 15.8 vs. 57.0 ± 18.3; p = 0.043). In patients, smaller JF areas were significantly associated with higher venous obstruction grading score (VOGS) both on the right (p = 0.018) and on the left side (p = 0.005). Positional plagiocephaly (cranial vault asymmetry index > 3.5%) was more frequent among EH patients than controls (38/17) but the difference was not significant (p = 0.07). In the 38 plagiocephalic patients, JF area was smaller on the flattened side than the contralateral in a significant number of cases both in right (21/7) and left (9/1) plagiocephaly (p < 0.0005) as well as the mean area (48.2 + 16.4 mm2 vs. 57.5 + 20.7 mm2, p = 0.002) and VOGS was significantly higher on the plagiocephalic side than on the contralateral side (1.6 ± 1.1 vs. 1.1 ± 0.9, p = 0.019). CONCLUSION: In this series of infants affected by EH, the mean size of the ostium of both JF resulted significantly smaller than controls. JF stenosis was significantly associated with higher degrees of venous obstruction on both sides, suggesting a direct extrinsic effect of JF size on dural sinus lumen and possible consequent effect on venous outflow resistance. Positional plagiocephaly, when present, was associated with a decreased JF area and increased VOGS on the flattened side.

Surgical Approaches to the Third Ventricle: An Update.

The third ventricle is located in the deepest part of the brain and is delimited by both telencephalic and diencephalic structures. Its location makes every surgical procedure inside or around it quite challenging, due to the distance from the surface to the fragility of the neurovascular structures that is necessary to dissect before entering its cavity and to the narrow surgical corridors through which it is necessary to work. Its geometric localization inside the cranial cavity and the anatomical relationship with the interhemispheric fissure offers nevertheless to the surgeon an impressive variety of surgical approaches, which allow to reach every millimeter of the third ventricle lumen. Mastering properly all these approaches requires an impressive anatomical knowledge, the best available technology, and most refined technical skills, making the surgery of the third ventricle a point of excellence in the evolution of each neurosurgeon. The development of neuronavigation and neuroendoscopy has been a revolution in neurosurgery in the last 20 years and offered special advantages for the surgery of the third ventricle. In fact, the narrow corridors of approach make the precision of the neuronavigation and the enlightenment and magnification of the neuroendoscopy especially useful to reach the third ventricle cavity and working inside or around it. This chapter reviews the history of the surgery of the third ventricle and offers an update of the variety of surgical corridors identified and of the technology now available to properly work through them and inside the third ventricle cavity.

Endoscopic ultrasonic aspiration of posterior fossa abscess in Dandy-Walker malformation: case report.

BACKGROUND: Dandy-Walker malformation (DWM) is a posterior fossa malformation characterized by a huge posterior fossa cyst in communication with the fourth ventricle. Hydrocephalus is associated with more than 80% of cases and is usually treated by shunting. Despite infection being a common complication of the shunt, abscess formation within the cyst was reported only once. CASE REPORT: A neonate affected by DWM developed a posterior fossa abscess following a shunt infection. The purulent collection was refractory to standard treatment (antibiotics and burr hole drainage); therefore, an endoscopic approach was performed in order to remove the purulent collection under direct vision. This material was aspirated with the help of an endoscopic ultrasonic aspirator. The outcome was favorable, with a resolution of infection and re-implantation of the ventriculo-peritoneal shunt. Surprisingly, post-operative radiological examination showed substantial modification of the anatomy of the posterior fossa with disappearing of the Dandy-Walker cyst. To the best of our knowledge, this is the first documented report of a true Dandy-Walker malformation that modified its anatomical appearance over time. DISCUSSION AND CONCLUSION: Endoscopic aspiration of intracranial purulent collection should be considered a valid option to manage complicated cases. An endoscopic ultrasonic aspirator may make the procedure more effective and faster.

Hemostasis in a giant intraventricular tumor using a saline-cooled radiofrequency bipolar coagulator: technical note.

BACKGROUND: Meningiomas are relatively rare in children and tend to be intraventricular and cystic, with often malignant behavior. Complete excision is associated with the most favorable outcome; moreover, the size and extent of these lesions often make complete excision in one step impossible because of the risk of intraoperative death from uncontrollable hemorrhage. CASE PRESENTATION: A 10-year-old girl was admitted for headache in the last 3 months and was found to have a giant left intraventricular lesion with a volume of 166.63 cm3, which caused hydrocephalus and significant mass effect. Very large draining veins were evident within the tumor, draining into the thalamostriates and internal cerebral veins. Cerebral angiography showed multiple feeders originating mainly from branches of the posterior left choroidal artery with distal afferents that could not be embolized. Therefore, a left parietal transcortical approach was chosen. Given the vascularity of the tumor, saline-cooled radiofrequency coagulation (Aquamantys®) was used to reduce blood loss intraoperatively. Gross total resection (GTR) was achieved with an estimated blood loss of 640 mL. Pathology analysis was consistent with WHO grade 1 transitional meningioma. Postoperatively, the patient was neurologically intact, and MRI confirmed complete resection. CONCLUSION: Aquamantys® is a novel bipolar coagulation device that employs a new bipolar coagulation technique combining radiofrequency energy and saline to achieve hemostatic sealing by denaturing collagen fibers. This offers the possibility of achieving adequate hemostasis even in giant intraventricular tumors in infants to obtain GTR resection with minimal blood loss.

Pure endoscopic ultrasonic removal of choroid plexus papillomas of the third ventricle: technical report of two cases.

BACKGROUND: Tumors of the choroid plexus of the third ventricle are uncommon. Surgical excision is technically challenging because of the rich vascularisation, central location, and high incidence in young children. Open microsurgical resection is considered the standard treatment. However, attempts at purely endoscopic removal of choroid plexus tumors of the third ventricle have also been made in the past, with encouraging results. CASE REPORTS: We report our experience with endoscopic ultrasonic removal of two cases of tumors of the third ventricular choroid plexus. The first case was a large atypical choroid plexus papilloma (WHO grade 2) in the anterior third ventricle associated with hydrocephalus; the second case was a smaller choroid plexus papilloma (WHO grade 1) in the middle/posterior third ventricle without overt hydrocephalus requiring a more anterior neuronavigation guided approach. DISCUSSION AND CONCLUSION: Choroid plexus papillomas of the third ventricle can be safely treated by a purely endoscopic approach because they are usually smaller than their counterparts in the lateral ventricle and often have a recognizable vascular pedicle. Early detection and control of the vascular pedicle at the choroidal border is key to success. The use of ultrasonic aspirator facilitates and expedites endoscopic access. By alternating surface coagulation with fragmentation and aspiration with the ultrasonic aspirator, the tumor can be removed without difficult dissection maneuvers.

Neuroendoscopy: intraventricular and skull base tumor resection in children.

During the last 30 years, the neurosurgeons have witnessed a revolution in the practice of interventricular surgery. The advent of neuroendoscopy at the end of the 1980s has allowed a minimally invasive management of a very large series of pathologies in pediatric neurosurgery ranging from hydrocephalus to arachnoid cyst to intraventricular tumors. The progresses in the management of hydrocephalus, intracranial cyst, and the fluid filled collection nevertheless has been more rapid and radical due to the simpler equipment that is necessary to perform this kind of surgery. The intraventricular tumors instead have been addressed in a slower way, and for many years, the only endoscopic procedure that was allowed on interventricular tumors was a biopsy associated with the management of hydrocephalus. Only very small tumors have been considered operable for complete removal during many years due to the limitations of the neuroendoscopic equipment and to the small calibers of the working channel. More recently, the advent of new devices and new surgical techniques are offering new perspectives on the possibility of intraventricular tumor surgery in children. In this review, we describe the historical perspective of the learning curve of intraventricular tumor surgery under neuroendoscopic control and try to offer a view of the future perspective in the removal of larger intraventricular tumors, analyzing the main indications for intraventricular endoscopic tumor surgery. We offer as well an historical perspective of the evolution of skull base surgery and endonasal transsphenoidal approach for skull-based tumors in children. This kind of surgery that has acquired widespread acceptance for many pathologies in adult age has diffused more slowly in pediatric neurosurgery due to the anatomical limitation observed in these age range. Also in this field, the slow evolution of the technique and of the technology available to neurosurgeons has allowed a very significant expansion of indication for the minimally invasive removal of skull base tumors in children.

Endoscopic ultrasonic aspirator-assisted removal of a third ventricular colloid cyst.

BACKGROUND: Colloid cysts are benign tumors usually located on the roof of the third ventricle. Cyst removal is the treatment of choice. It can be accomplished microsurgically through a transcortical- or transcallosal approach, or endoscopically. There is a lack of consensus regarding the best strategy for cyst removal. One of the challenges of the traditional endoscopic technique is dealing with the cyst content density. Hyperdensity on computed tomography scan and low signal on T2-weighted magnetic resonance imaging (MRI) cyst are correlated with high viscosity cystic content. CASE REPORTS: We present a case of a colloid cyst of the third ventricle in a 15-year-old boy removed through a pure endoscopic transventricular approach. The cyst presented a low signal on T2 MRI; nevertheless, it was easily removed with the help of an endoscopic ultrasonic aspirator. DISCUSSION AND CONCLUSION: The colloid cyst of the third ventricle can be safely treated by a purely endoscopic approach. The rationale of the use of the ultrasonic aspirator relies on the facilitation of aspiration of the content even when the consistency is extremely firm.

Fourth ventricle to spinal subarachnoid space stenting in pediatric patients with refractory syringomyelia: case series and systematic review.

A series of 5 patients treated with the fourth ventricle to spinal subarachnoid space stent (FVSSS) is presented. Indication for surgery, surgical technique, pre-operative and post-operative images, and outcome are analyzed. A systematic review of the pertinent literature has also been performed. This is a retrospective cohort review of a series of 5 consecutive patients with refractory syringomyelia who underwent a fourth ventricle to spinal subarachnoid space shunt surgery. The surgical indication was based on the presence of refractory syringomyelia in patients already treated for Chiari malformation or in patients who developed scarring at the level of the outlets of the fourth ventricle following posterior fossa tumor surgery. The mean age at FVSSS was 11.30 ± 5.88 years. Cerebral MRI revealed crowded posterior fossa, with a membrane at the level of the foramen of Magendie. Spinal MRI showed syringomyelia in all patients. Before surgery, the averages of the craniocaudal and the anteroposterior diameter were 22.66 and 1.01 cm, respectively, whereas the volume was 28.16 cm3. The post-operative period was uneventful in 4 out of 5 patients; one child died on the 1st post-operative day due to complications unrelated to surgery. In remaining cases, syrinx marked improvement. The post-operative volume was 1.47 cm3 with an overall reduction of 97.61%. With regard to literature, 7 articles with a total of 43 patients were analyzed. After FVSSS, syringomyelia reduction was observed in 86.04% of cases. Three patients underwent reoperation due to syrinx recurrence. Four patients presented a catheter displacement, one a wound infection and meningitis and one CSF leak requiring placement of a lumbar drain. FVSSS is highly effective in restoring CSF dynamics, with dramatic improvement of syringomyelia. In all our cases, the volume of the syrinx was reduced by at least 90%, with improvement/resolution of accompanying symptomatology. This procedure should be reserved to patients in which other causes of gradient pressure between the fourth ventricle and subarachnoid space are excluded, for example, tetraventricular hydrocephalus. Surgical procedure is not simple, because it requires meticulous microdissection of cerebello-medullary fissure and upper cervical spine, in already operated patients. To avoid migration of the stent, it should be carefully sutured to the dura mater or thick arachnoid membrane.

Tumors of Choroid Plexus and Other Ventricular Tumors.

Tumors arising inside the ventricular system are rare but represent a difficult diagnostic and therapeutic challenge. They usually are diagnosed when reaching a big volume and tend to affect young children. There is a wide broad of differential diagnoses with significant variability in anatomical aspects and tumor type. Differential diagnosis in tumor type includes choroid plexus tumors (papillomas and carcinomas), ependymomas, subependymomas, subependymal giant cell astrocytomas (SEGAs), central neurocytomas, meningiomas, and metastases. Choroid plexus tumors, ependymomas of the posterior fossa, and SEGAs are more likely to appear in childhood, whereas subependymomas, central neurocytomas, intraventricular meningiomas, and metastases are more frequent in adults. This chapter is predominantly focused on choroid plexus tumors and radiological and histological differential diagnosis. Treatment is discussed in the light of the modern acquisition in genetics and epigenetics of brain tumors.

Malignant cerebral infarction associated with COVID-19 in a child.

Neurological manifestations, such as encephalitis, meningitis, ischemic, and hemorrhagic strokes, are reported with increasing frequency in patients affected by Coronavirus disease 2019 (COVID-19). In children, acute ischemic stroke is usually multifactorial: viral infection is an important precipitating factor for stroke. We present a case of a child with serological evidence of SARS-CoV-2 infection whose onset was a massive right cerebral artery ischemia that led to a malignant cerebral infarction. The patient underwent a life-saving decompressive hemicraniectomy, with good functional recovery, except for residual hemiplegia. During rehabilitation, the patient also developed a lower extremity peripheral nerve neuropathy, likely related to a long-Covid syndrome.

The effect of image-guided ventricular catheter placement on shunt failure: a systematic review and meta-analysis.

INTRODUCTION: Cerebrospinal fluid (CSF) diversion for the treatment of hydrocephalus is one of the most common neurosurgical procedures. Over the years, the development of the neuronavigation system has allowed the surgeon to be guided in real time during the procedures. Nevertheless, to date, the revision rate remains as high as 30-40%. The aim of this study was to investigate the role of intraoperative image guidance in the prevention of shunt failure. We herein report the first literature meta-analysis of image guidance and shunt revision rate in the pediatric population. METHODS: Principal online databases were searched for English-language articles published between January, 1980, and December, 2021. Analysis was limited to articles that included patients younger than 18 years of age at the time of primary V-P shunt. Articles reporting combined results of free-hand and image-guided placement of ventricular catheter (VC) were included. The main outcome measure of the study was the revision rate in relation to the intraoperative tools. Secondary variables collected were the age of the patient and ventricle size. Statistical analyses and meta-analysis plots were done via R and RStudio. Heterogeneity was formally assessed using Q, I2, and τ2 statistics. To examine publication bias was performed a funnel plot analysis. RESULT: A total of 9 studies involving 2017 pediatric patients were included in the meta-analysis. 55.9% of procedures were carried out with the aid of intraoperative tools, while 44.1% procedures were conducted free hand. The intraoperative tools used were ultrasound (9.1%), electromagnetic neuronavigation (21.07%), endoscope (67.32%), and combined images (2.4%).The image-guided placement of VC was not statistically associated with a lower revision rate. The pooled OR was 0.97 [CI 95% 0.88-1.07] with an I2 statistics of 34%, t2 of 0.018 and a p-value of 0.15 at heterogeneity analysis. CONCLUSION: Our analysis suggest images guidance during VC shunt placement does not statistically affect shunt survival. Nevertheless, intraoperative tools can support the surgeon especially in patients with difficult anatomy, slit ventricles or complex loculated hydrocephalus.

Giant intracranial infantile myofibromatosis of the skull base: report of two cases.

Infantile myofibromatosis is a rare and nonmalignant pediatric tumor of myofibroblastic origin that may occur in solitary or multifocal forms. Soft tissue of the head and neck, trunk, and extremities, skeleton, and viscera are usually involved. Intracranial involvement is reported to be extremely rare, and its clinical picture has been poorly characterized. We present two cases of giant infantile myofibromatosis of the skull base with intracranial involvement. The first case with prenatal diagnosis involved extensively the extradural space of the occipital region and was previously treated by chemotherapy for a previous diagnosis of hemangioperycitoma. Tumor was removed at the age of 5 months and no recurrence was observed during the 3-year follow-up. The second case in a 2-year-old baby involved the anterior cranial base, the nasal cavity, the right orbit, and presented massive involvement of the anterior cranial fossa. Surgery allowed complete removal and a recurrence-free period of 7 years after surgery. Treatment options for these unusual cases are presented and details of histological diagnosis are discussed.

Primary leptomeningeal medulloblastoma: a case-based review.

BACKGROUND: Medulloblastoma (MB) is the most common malignant pediatric brain tumor, accounting for 40% of childhood tumors in posterior fossa. Metastatic disease, occurring in 20-30% of all medulloblastoma cases at diagnosis, is largely exclusive to the leptomeninges. On the contrary, primary leptomeningeal medulloblastoma or so-called chameleon medulloblastoma, defined by the absence of a detectable intraparenchymal lesion with a widespread diffusion along leptomeninges, is a rare entity of difficult diagnosis with only a few cases reported in literature. METHODS AND RESULTS: A comprehensive literature search of three databases (PubMed, Ovid Medline, and Ovid Embase) have been conducted to identify pertinent papers focusing on the diagnostic process, management, and treatment of primary leptomeningeal medulloblastoma and its peculiar features. To our knowledge, only eight cases are described in literature, including five pediatric patients and three adults, two of which with the initial involvement of the spinal cord. In addition, we report another two pediatric cases, showing widespread primary diffusion along leptomeninges of brain and spinal cord. Finally, we analyze in-depth the peculiar morphological MRI features of this tumor. CONCLUSION: The classification and treatment of medulloblastomas are likely to change in the coming years due to new insights into the molecular biology of medulloblastoma. Primary leptomeningeal medulloblastoma could represent another potential challenge for biologists to start exploring the underlying mechanisms of this different clinical and pathological entity, with different implications for diagnosis and its management.

Endoscopic ultrasonic aspiration as alternative to more invasive surgery in initial management of optic pathway gliomas in children.

INTRODUCTION: Optic pathway gliomas (OPGs) presenting with acute hydrocephalus represent a true neurosurgical and neurooncological challenge. Two main strategies are currently used: microsurgical removal of the tumor, restoring CSF pathways, and endoscopic biopsy associated with ventriculo-peritoneal shunt implantation. Since the availability of an ultrasonic aspirator handpiece, that can be used inside the working channel of a neuroendoscope, a different less invasive surgical strategy can be used. METHODS: Four pediatric patients were treated by endoscopic ultrasonic aspiration, in order to remove the upper pole of the tumor, obtaining tissue for diagnosis and restoring CSF pathways as initial treatment of OPG invading the third ventricle and causing hydrocephalus due to simultaneous blockage of both Monro foramina and of the Sylvian aqueduct. Surgical technique is described. Pre-operative and post-operative volumes were calculated on magnetic resonance imaging. RESULTS: In all cases, the surgical procedure was uneventful, the biopsy was diagnostic, and CSF pathways were restored. The amount of tumor removed ranged between 31 and 76%. All patients underwent oncological treatment of their tumors. One patient received V-P shunt only 1 year after endoscopic decompression due to tumor progression. CONCLUSION: Our preliminary results show that the use of endoscopic cavitron aspirator is safe and effective to obtain CSF flow restoration and tumor biopsy (for histological and molecular purposes), avoiding CSF shunt implant in the acute phase and offering the chance to obtain a consistent tumor debulking in a minimally invasive fashion. Neuroendoscopic approach together with modern target therapy offers the opportunity to avoid or delay major surgery.

Desmoplastic infantile astrocytoma and ganglioglioma: a series of 12 patients treated at a single institution.

BACKGROUND: Desmoplastic infantile astrocytomas and gangliogliomas (DIA/DIG) usually present with a large size, large cystic component, large dural implant, encasement of big vessels, clinical presentation within 18 months of life, high incidence of seizures and overall good prognosis, even if tumour surgery can be very challenging at first procedure. METHODS: We retrospectively reviewed clinical and radiological data of patients diagnosed with desmoplastic infantile tumours who were surgically treated between 2008 and 2019. RESULTS: The series included 12 patients. The median age at surgery was 91 days. The average tumour volume was 212 cm3. Cystic components were predominant ranging from 0 to 295 cm3. Active hydrocephalus was pre-operatively evident in 5 cases. Eight patients (66.6%) received total or subtotal removal, three of them (25%) underwent partial removal, and one patient (8.3%) received a biopsy. One patient died within 24 h after surgery due to severe hypotension, as a consequence of significant intraoperative blood loss. Overall, seven (58.3%) patients were reoperated on the tumour after the first procedure: 4 patients were operated twice; 3 patients were operated 3 times. Two patients presented remote localizations and underwent chemotherapy. At last follow-up, 7 patients were tumour-free, 2 are alive with stable disease, and 2 are alive with progressive disease (leptomeningeal seeding). CONCLUSION: Desmoplastic infantile tumours are rare giant neonatal tumours. Total removal is the goal of treatment, but prognosis remains good even if total removal is not achieved. In case of tumour progression or epilepsy from residual tumour, reoperation is the first option, with chemotherapy reserved to unresectable or disseminated cases with mixed results, while, to date, radiotherapy still plays no role.

Endoscopic aqueductoplasty and stenting in the treatment of isolated fourth ventricle in children: 20-year institutional experience.

BACKGROUND: Endoscopic aqueductoplasty with aqueductal stenting is an effective surgical procedure for the treatment of isolated fourth ventricle (IFV). Due to the rarity of the underlying pathology, it can be considered a rare procedure that can be performed with different surgical techniques and approaches. OBJECTIVES: To assess long-term functioning of permanent aqueductal stents implanted in children affected by hydrocephalus and IFV and to describe some variations of the same procedure. METHODS: We reviewed retrospectively all the patients presenting at our institution in the years 1999-2019 for symptoms of isolated fourth ventricle who underwent a surgical procedure of endoscopic aqueductoplasty and/or aqueductal stent. Surgical reports, radiological images, and surgical videos were retrospectively analyzed. RESULTS: Thirty-three patients with symptomatic isolated fourth ventricle (IFV) underwent fifty (50) neuroendoscopic procedures in the period observed. The median age of the patients at the time of first surgery was 7 months, with 22 premature babies. In twenty-nine patients (87.8%), a precoronal approach was performed, while four patients received a suboccipital burr hole. Ten patients were never reoperated since. Twenty-three patients underwent further surgeries: a new aqueductoplasty with aqueductal stent was performed in 13 cases. The remaining 10 patients required a combination of other procedures for management of hydrocephalus. Long-term follow-up showed a permanent stent functioning rate of 87% at 2 years and 73% at 4 years, remaining stable afterwards at very long term (20 years). CONCLUSION: Endoscopic aqueductoplasty and stenting is a reliable procedure in the long-term management of isolated fourth ventricle.

Dural venous sinus anatomy in children with external hydrocephalus: analysis of a series of 97 patients.

PURPOSE: To evaluate the anatomical variations of dural venous sinuses in children with external hydrocephalus, proposing a radiological grading of progressive anatomic restriction to venous outflow based on brain phase-contrast magnetic resonance venography (PC-MRV); to evaluate the correlation between positional plagiocephaly and dural sinuses patency; and to compare these findings with a control group to ascertain the role of anatomical restriction to venous outflow in the pathophysiology of external hydrocephalus. METHODS: Brain MRI and PC MRV were performed in 97 children (76 males, 21 females) diagnosed with external hydrocephalus at an average age of 8.22 months. Reduction of patency of the dural sinuses was graded as 1 (stenosis), 2 (complete stop) and 3 (complete agenesis) for each transverse/sigmoid sinus and sagittal sinus. Anatomical restriction was graded for each patient from 0 (symmetric anatomy of patent dural sinuses) through 6 (bilateral agenesis of both transverse sinuses). Ventricular and subarachnoid spaces were measured above the intercommissural plane using segmentation software. Positional plagiocephaly (PP) and/or asymmetric tentorial insertion (ATI) was correlated with the presence and grading of venous sinus obstruction. These results were compared with a retrospective control group of 75 patients (35 males, 40 females). RESULTS: Both the rate (84.53% vs 25.33%) and the grading (mean 2.59 vs mean 0.45) of anomalies of dural sinuses were significantly higher in case group than in control group. In the case group, sinus anomalies were asymmetric in 59 cases (right-left ratio 1/1) and symmetric in 22. A significant association was detected between the grading of venous drainage alterations and diagnosis of disease and between the severity of vascular anomalies and the widening of subarachnoid space (SAS). Postural plagiocephaly (39.1% vs 21.3%) and asymmetric tentorial insertion (35.4% vs 17.3%) were significantly more frequent in the case group than in the control group. When sinus anomalies occurred in plagiocephalic children, the obstruction grading was significantly higher on the flattened side (p ≤ 0.001). CONCLUSION: Decreased patency of the dural sinuses and consequent increased venous outflow resistance may play a role in the pathophysiology of external hydrocephalus in the first 3 years of life. In plagiocephalic children, calvarial flattening may impact on the homolateral dural sinus patency, with a possible effect on the anatomy of dural sinuses and venous drainage in the first months of life.

Repair of giant lumbosacral pseudomeningocele with fast-resorbing polymer mesh in a pediatric patient operated for posterior dysraphism.

Lumbar pseudomeningocele is a common complication of spinal surgery. It is caused by dural defect, and it consists of extradural collection of cerebrospinal fluid communicating with subarachnoid space. Usually it is small, asymptomatic, and self-limiting. In case of persistence, common treatments include bedrest, puncture and compressive dressing, subcutaneous or subarachnoid lumbar drainage, surgical re-exploration for durotomy closure, and blood patch. Fast-resorbing polymer mesh has been recently used for closure osseous gap in adult patients who developed giant pseudomeningocele following laminectomy. We report the case of a 16-year-old girl, affected by spinal dysraphism, who developed a persistent giant lumbar pseudomeningocele after repeated surgery for detethering of the spinal cord and removing of spinal lipomyelomeningocele. She was finally treated with fast-resorbing polymer mesh, to fill the gap of the posterior osseous defect and to provide support for the thecal sac. For our best knowledge, this is the first pediatric case reported in literature on this kind of reconstruction. In complex cases of pseudomeningocele, implant of fast-resorbing polymer mesh may represent an option also in pediatric patients.