Biobank for craniosynostosis and faciocraniosynostosis, rare pediatric congenital craniofacial disorders: a study protocol.

PURPOSE: Craniosynostosis (CRS) is a rare congenital cranial malformation in which 1 or more cranial or facial sutures are fused in utero or rapidly fused in early infancy. The cranial sutures separate the skull bone plates and enable rapid growth of the skull in the first 2 years of life, in which growth is largely dictated by growth of the brain. CRS is a rare disease that occurs in 1 in 2100 to 1 in 2500 births and may be either nonsyndromic (also referred to as isolated) or syndromic. In syndromic CRS, other birth defects are present next to the CRS. The distinction between nonsyndromic and syndromic manifestations is made on the basis of dysmorphologic evaluation and genetic evaluation. Owing to advances in genetic diagnostics, nonsyndromic patients are increasingly recognized as syndromic patients. CRS treatment is almost entirely surgical and is sometimes paired with postoperative helmet therapy for maintenance. Corrective procedures are complex, long, and associated with the risk of numerous complications, including heavy blood loss and its sequelae. Although surgery may restore a normal appearance, even in nonsyndromic patients, patients may experience persistent deficits in intellectual ability and cognitive function. The European Commission (EC) has prioritized rare diseases in recent horizon European research programs; indeed, collections or even individual samples may be extremely valuable for research. METHODS AND RESULTS: Here, we present a study protocol in which the combined expertise of clinicians and researchers will be exploited to generate a biobank dedicated to CRS. The generation of the CRS biobank presented in this study will include the collection of different types of biological materials as well as advanced radiological images available to the scientific community. CONCLUSION: The activation of a CRS biobank will provide an opportunity to improve translational research on CRS and to share its benefits with the scientific community and patients and their families.

Changes in venous drainage after posterior cranial vault distraction and foramen magnum decompression in syndromic craniosynostosis.

OBJECTIVE: The authors' objective was to measure the effect of posterior cranial vault distraction (PCVD) plus foramen magnum decompression (FMD) on dural sinus volume and venous flow in patients with syndromic craniosynostosis. METHODS: The volumes of the sagittal, straight, transverse, and sigmoid sinuses of 5 consecutive patients with syndromic craniosynostosis who underwent PCVD+FMD were calculated in cubic centimeters with T2-weighted volumetric MRI sequences before surgery, immediately after surgery, and after the end of the distraction process. Tridimensional reconstructions of phase-contrast magnetic resonance angiography (PC-MRA) images were obtained with multiplanar reconstruction (MPR). RESULTS: The average total volume of all dural sinuses increased immediately after surgery (from 10.06 cm3 to 12.64 cm3) and continued to increase throughout the 30-day distraction period (from 12.64 cm3 to 14.71 cm3) (p = 0.04), except that the right sigmoid sinus remained stable after the initial increase. The most important increases were observed for the left transverse sinus (+113.2%), right transverse sinus (+104.3%), left sigmoid sinus (+91.3%), and sagittal sinus (+41.8%). Less important modifications were evident for the right sigmoid sinus (+33.7%) and straight sinus (+23.4%). Significant improvements in venous flow were noted on the tridimensional reconstructions of the PC-MRA images. Venous obstruction grading score improved in 4 patients (average [range] 2.4 [ 2-5]) (p = 0.023) and remained stable in 1 patient. All patients had chronic tonsillar herniation (CTH) (mean [range] 16.6 [8-26] mm), and 3 had syringomyelia. CTH showed improvement on the last follow-up MRI evaluation in 4 patients (mean [range] 10.5 [0-25] mm) and worsened from 15 mm to 19 mm in 1 patient. Syringomyelia improved in 2 patients and remained unchanged in 1. CONCLUSIONS: This study has provided the first radiological evidence of the impact of craniofacial surgery on dural sinus anatomy and venous drainage. The venous anomalies described in patients with syndromic craniosynostosis are not static, and PCVD+FMD triggers a dynamic process that can lead to significant modifications of intracranial venous drainage. The traction exerted by the distracted bone flap onto the occipitoparietal dura mater adherent to the inner calvaria may account for the enlargement of the dural sinus throughout the distraction period. The impact of these modifications on venous pressure, intracranial pressure, CTH, and hydrocephalus remains to be determined.

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.

A novel MEIS2 mutation explains the complex phenotype in a boy with a typical NF1 microdeletion syndrome.

Concurrence of distinct genetic conditions in the same patient is not rare. Several cases involving neurofibromatosis type 1 (NF1) have recently been reported, indicating the need for more extensive molecular analysis when phenotypic features cannot be explained by a single gene mutation. Here, we describe the clinical presentation of a boy with a typical NF1 microdeletion syndrome complicated by cleft palate and other dysmorphic features, hypoplasia of corpus callosum, and partial bicoronal craniosynostosis caused by a novel 2bp deletion in exon 2 of Meis homeobox 2 gene (MEIS2) inherited from the mildly affected father. This is only the second case of an inherited MEIS2 intragenic mutation reported to date. MEIS2 is known to be associated with cleft palate, intellectual disability, heart defects, and dysmorphic features. Our clinical report suggests that this gene may also have a role in cranial morphogenesis in humans, as previously observed in animal models.

Temporal lobe malformations, focal epilepsy, and FGFR3 mutations: a non-causal association?

Temporal lobe abnormalities and focal epilepsy have been documented in FGFR3-related clinical condition, including hypochondroplasia and Muenke syndrome. FGFR3 is expressed in the brain during development and could play a role in nervous system development and hippocampal formation. These observations suggest a non-casual association between temporal malformation, epilepsy, and FGFR3 mutations. Herein, we report clinical, electroclinical, and neuroimaging findings of three additional cases of focal epilepsy and temporal lobe malformations occurring in children with FGFR3 gene mutations.

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.

Brain Herniation into the Subdural Space: Rare Iatrogenic Complication of Treatment of a Giant Calcified Subdural Hematoma.

BACKGROUND: Chronic subdural hematoma associated with dural calcifications in previously pediatric shunted patients is a rare condition. The inner dural membrane opening can lead to progressive brain herniation into the subdural space due to brain reexpansion. CASE DESCRIPTION: A 15-year-old boy, previously shunted at birth for congenital hydrocephalus, presented with a giant chronic right hemispheric subdural hematoma. After 2 surgical procedures in which the subdural calcified neomembrane was opened and a subdural shunt was implanted, he developed a cortical brain herniation into the subdural space, resulting in brain ischemia and upper limb weakness and vomiting. The final surgical treatment consisted of an extensive wide peeling of visceral calcified membrane mutually to programmable valve placement along the subduroperitoneal shunt, in order to create a positive gradient between the subdural space and the ventricles. The patient experienced a prompt clinical improvement. CONCLUSIONS: This case illustrates a rare complication of the treatment of a chronic subdural hematoma caused by insufficient opening of the calcified inner mambrane of the hematoma and encouraged by gradient pressure between the ventricular and subdural compartments. To avoid this complication, it is preferable to not open a thick, calcified, unelastic inner membrane. However, in case of lack of clinical and radiologic improvement, it may become necessary to open it: a wide opening should be attempted, in order to prevent brain strangulation.

Endoscopic ultrasonic aspiration of brain abscess.

BACKGROUND: Intracerebral abscess is a rare, but very serious complication of neonatal sepsis. Aggressive medical and surgical strategy is warranted in patients with large abscesses. CASE REPORT: A neonate with bilateral large frontal abscesses, caused by Serratia marcescens, was operated using a neuroendoscope coupled with an ultrasonic aspiration device. To our knowledge, this is the first report of such utilization of this new tool. The left abscess was surgically drained through endoscopic aspiration using ultrasonic aspirator. Clinical condition rapidly improved, and postoperative MRI of the brain revealed an almost complete resolution of the left abscess. A second endoscopic procedure was performed 1 week later, and the right abscess was endoscopically drained with the same technique. The remaining clinical course was uneventful. DISCUSSION AND CONCLUSION: Ultrasonic aspiration is effective in obtaining complete removal of the purulent material and of the dense fibrin layer adherent to the capsule. However, further studies are warranted to determine its real effectiveness, compared with the classic technique. In our opinion, it should be considered an option in more difficult cases, such as abscesses caused by aggressive germs in young or immunocompromised patients, or in case of recurrent lesions, in order to avoid craniotomy and open surgery.

Surgical treatment of thalamic tumors in children.

OBJECTIVE In the past, the outcome of surgical treatment for thalamic tumor was poor. These lesions were often considered inoperable. However, contemporary microsurgical techniques, together with improvements in neuroimaging that enable accurate presurgical planning, allow resection to be accomplished in a safer way. METHODS The medical records, imaging studies, and operative and pathology reports obtained for pediatric patients who were treated for thalamic tumors at the authors' department were reviewed. Neuronavigation and intraoperative monitoring of motor and somatosensory evoked potentials were used. Preoperative tractography, which helped to identify internal capsule fibers, was very important in selecting the surgical strategy. Postoperatively, an MRI study performed within 24 hours was used to assess the extent of tumor resection as partial (≤ 90%), subtotal (> 90%), or gross total (no residual tumor). RESULTS Since 2002, 27 children with thalamic tumors have been treated at the authors' department. There were 9 patients with unilateral thalamic tumors, 16 with thalamopeduncular tumors, and 2 with a bilateral tumor. These last 2 patients underwent endoscopic biopsy and implantation of a ventriculoperitoneal shunt. Thirty-nine tumor debulking procedures were performed in the remaining 25 patients. Different surgical approaches were chosen according to tumor location and displacement of the posterior limb of the internal capsule (as studied on axial T2-weighted MRI) and corticospinal tract (as studied on diffusion tensor imaging with tractography, after it became available). In 12 cases, multiple procedures were performed; in 7 cases, these were done as part of a planned multistage resection. In the remaining 5 cases, the second procedure was necessary because of late recurrence or regrowth of residual tumor. At the end of the surgical phase, of 25 patients, 15 (60%) achieved a gross-total resection, 4 (16%) achieved a subtotal resection, and 6 (24%) achieved a partial resection. Eighteen patients harbored low-grade tumors in our series. In this group, the mean follow-up was 45 months (range 4-132 months). At the end of follow-up, 1 patient was dead, 12 patients were alive with no evidence of disease, 4 patients were alive with stable disease, and 1 was lost to follow-up. All patients were independent in their daily lives. The outcome of high-grade tumors in 9 patients was very poor: 2 patients died immediately after surgery, 6 died of progressive disease, and 1 was alive with residual disease at the time of this report. CONCLUSIONS This institutional review seems to offer further evidence in favor of attempts at radical resection in pediatric patients harboring unilateral thalamic or thalamopeduncular tumors. In low-grade gliomas, radical resection in a single or staged procedure can be curative without complementary treatment. Recurrences or residual regrowth can be safely managed surgically. In high-grade tumors, the role of and opportunity for radical or partial resection remains a matter of debate.

Giant melanotic neuroectodermal tumor of infancy (melanotic progonoma) of the head and neck: report of a malignant case.

Melanotic neuroectodermal tumor of infancy is a rare congenital pigmented neoplasm of neural crest origin, locally aggressive, growing rapidly and developing during the 1st year of life. It most commonly arises from the maxilla, cranial vault, and mandible. Occasionally, it exhibits malignant behavior with local lymph nodes involvement. Cases misdiagnosed and left untreated for a long time can present challenges due to the tumor mass and infiltration. In these cases, adjuvant chemotherapy can be extremely helpful before radical excision. Authors of this report describe a 4-year-old boy from a developing country who was referred to their hospital with an ulcerated bulging lesion in the midline/right parietooccipital region, extending to the right laterocervical and parotid regions, resulting in significant craniofacial deformation. Magnetic resonance imaging of the brain revealed a highly enhancing tumor with intracranial and extracranial development extending mainly at the level of the right parietooccipital region, with lytic and hypertrophic alterations of the skull. The patient was managed with neoadjuvant and adjuvant chemotherapy and radically resective surgery on metastatic lymph nodes and the primary tumor of the skull. Scheduled radiotherapy was not performed, according to the parents' wishes. The patient returned to his native country where the lesion recurred, and he ultimately died approximately 10 months after the end of the treatment. The literature indicates that tumor removal alone has been the treatment of choice in most isolated cases, but in cases of highly advanced tumor with involvement of the skull and cervical lymph nodes, it is preferable to proceed with preoperative chemotherapy with the aim of reducing the tumor volume, allowing better technical conditions for complete surgical removal, and decreasing the risk of local recurrence or metastasis.

Initial experience with endoscopic ultrasonic aspirator in purely neuroendoscopic removal of intraventricular tumors.

OBJECTIVE Neuroendoscopic removal of intraventricular tumors is difficult and time consuming because of the lack of an effective decompression system that can be used through the working channel of the endoscope. The authors report on the utilization of an endoscopic ultrasonic aspirator in the resection of intraventricular tumors. METHODS Twelve pediatric patients (10 male, 2 female), ages 1-15 years old, underwent surgery via a purely endoscopic approach using a Gaab rigid endoscope and endoscopic ultrasonic aspirator. Two patients presented with intraventricular metastases from high-grade tumors (medulloblastoma, atypical teratoid rhabdoid tumor), 2 with subependymal giant cell astrocytomas (associated with tuberous sclerosis), 2 with low-grade intraparaventricular tumors, 4 with suprasellar tumors (2 craniopharyngiomas and 2 optic pathway gliomas), and 2 with pineal tumors (1 immature teratoma, 1 pineal anlage tumor). Hydrocephalus was present in 5 cases. In all patients, the endoscopic trajectory and ventricular access were guided by electromagnetic neuronavigation. Nine patients underwent surgery via a precoronal bur hole while supine. In 2 cases, surgery was performed through a frontal bur hole at the level of the hairline. One patient underwent surgery via a posterior parietal approach to the trigone while in a lateral position. The endoscopic technique consisted of visualization of the tumor, ventricular washing to dilate the ventricles and to control bleeding, obtaining a tumor specimen with biopsy forceps, and ultrasonic aspiration of the tumor. Bleeding was controlled with irrigation, monopolar coagulation, and a thulium laser. RESULTS In 7 cases, the resection was total or near total (more than 90% of lesion removed). In 5 cases, the resection was partial. Histological evaluation of the collected material (withdrawn using biopsy forceps and aspirated with an ultrasonic aspirator) was diagnostic in all cases. The duration of surgery ranged from 30 to 120 minutes. One case was complicated by subdural hygroma requiring a subduro-peritoneal shunt implant. CONCLUSIONS In this preliminary series, endoscopic ultrasonic aspiration proved to be a safe and reliable method for achieving extensive decompression or complete removal in the management of intra- and/or paraventricular lesions in pediatric patients.

Contemporary occurrence of hydrocephalus and Chiari I malformation in sagittal craniosynostosis. Case report and review of the literature.

Chiari malformation type I (CM-I) and hydrocephalus are often associated with complex craniosynostosis. On the contrary, their simultaneous occurrence in monosutural synostosis is extremely rare. The pathophysiological hypothesis is that they may alter posterior fossa growth and lead to cerebellar tonsil herniation also without skull base primary involvement. Hydrocephalus is multifactorial and may be secondary to fourth ventricle outlet obstruction. The management of these cases is quite complex and not well defined. Cranial vault remodeling should be the only treatment when CM-I is asymptomatic and not related to syringomyelia. Suboccipital decompression should be reserved only in complicated CM-I, usually as a second surgical step following the correction of the supratentorial deformity. In our opinion, the associated hydrocephalus should be treated first in order to normalize intracranial hypertension before opening the cranial sutures. We report the case of a 26-month-old child that presented with sagittal craniosynostosis, hydrocephalus, and CM-I. He was managed by performing endoscopic third ventriculostomy (ETV) first and cranial vault remodeling thereafter. Clinico-radiological outcome was very satisfying. Concerning literature is reviewed; physiopathology and surgical management are discussed.

Grisel Syndrome Following Adenoidectomy: Surgical Management in a Case with Delayed Diagnosis.

BACKGROUND: Grisel syndrome is a nontraumatic rotatory subluxation of the atlantoaxial joint, following nasopharyngeal inflammation or ear, nose, and throat (ENT) procedures. The syndrome should be suspected in cases of persistent neck pain and stiffness, especially after ENT surgical procedures. The primary treatment of early detected Grisel syndrome is conservative. If conservative treatment fails to achieve a stable reduction or it is followed by neurologic symptoms, arthrodesis of the first and second cervical vertebrae is indicated. We report the case of a 9-year-old boy who developed Grisel syndrome after adenoidectomy and was treated with C1-C3 internal fixation and fusion. CASE DESCRIPTION: A 9-year-old boy was referred to our hospital with a 3-month history of painful torticollis, which appeared 4 days after adenoidectomy. The patient underwent a neuroimaging study that documented the presence of atlantoaxial rotatory subluxation. The patient underwent C1-C3 internal fixation and fusion, using lateral masses and laminar and pars interarticularis screws. On the third postoperative day he was mobilized with a rigid collar. Postoperative computed tomography scans showed the resolution of rotational deformity and a solid fusion. CONCLUSION: Early treatment of Grisel syndrome is of utmost importance to avoid neurologic complications and surgical intervention. In a patient with torticollis following ENT procedures, Grisel syndrome should be always suspected. In case of failure of conservative treatment or in case of delayed diagnosis, rigid C1-C2 or C1-C2-C3 fixation is a straightforward and valid surgical technique, even in children, because it provides immediate spinal stability in all planes at the atlantoaxial complex, avoiding the need for prolonged rigid external bracing.

Cortical gluing and Ringer lactate solution inflation to avoid cortical mantle collapse and subdural fluid collections in pediatric neurosurgery: safety and feasibility.

INTRODUCTION: Subdural fluid collections following intraventricular and/or paraventricular procedures in pediatric neurosurgery are common and can be hard to treat. We describe our technique to close cortical defects by the aid of a fibrin adhesive and subsequent Ringer inflation with the aim to avoid cortical mantle collapse and to prevent the development of subdural fluid collections. MATERIALS AND METHODS: We report the preliminary results of a prospective study on a consecutive series of 29 children who underwent 37 transcortical or transcallosal surgical procedures since 2008 in our department. RESULTS: In 17 procedures, we performed a transcortical approach on lesions, and in other 19 operations, we operated by a transcallosal. In 5/17 transcortical approaches (29%) and in 3/20 transcallosal approaches (15%), we observed a 5-mm-thick subdural fluid collection of the 5 patients with subdural fluid collections in the transcortical group, 3 patients (17%) underwent surgery for symptomatic or progressive subdural fluid collections. Of the 3 patients in the transcallosal group, a subduro-peritoneal shunt was necessary only for 1 patient (5%). At the very end of the treatment (including chemotherapy and radiotherapy), it was possible to remove the subduro-peritoneal shunt in all these patients because of disappearance of the subdural fluid collections. CONCLUSION: In pediatric patients after transcortical or transcallosal procedures, the use of a fibrin adhesive to seal surgical opening and subsequent inflation of the residual cavity with Ringer lactate solution to avoid cortical mantle collapse seems safe and appears to prevent the development of subdural fluid collections.

Interhemispheric and quadrigeminal cysts.

BACKGROUND: Interhemispheric and quadrigeminal cysts are rare lesions, similar in their propensity to present in young babies and to be associated with other central nervous system malformations, such as corpus callosum agenesia, holoprosencephaly, encephalocele, and neuronal heterotopias. Recently endoscopy has become increasingly popular in the treatment of arachnoid cysts, but experience with cysts located in the interhemispheric fissure and in the quadrigeminal cistern is limited. METHODS: This study reviews the specific anatomy of interhemispheric and quadrigeminal cysts and their relationship with the ventricular system and subarachnoid cisterns to select the most appropriated treatment. It also reviews the literature on endoscopic treatment of interhemispheric and quadrigeminal cysts. RESULTS: Interhemispheric and quadrigeminal cysts are not homogeneous, they have different extensions toward surrounding regions. In most cases it is presented as an area of contiguity between the cyst and ventricular system and/or subarachnoid cisterns, making endoscopic treatment feasible. The success rate for endoscopic treatment is not different from that reported in large series of arachnoid cysts elsewhere. CONCLUSIONS: Endoscopic treatment should be considered the first-line option in the treatment of such lesions, even if some complications, such as subdural collections due to thinness of the cerebral mantle or subcutaneous CSF collections due to multifactorial associated hydrocephalus, must be expected.

Third ventriculostomy in shunt malfunction.

BACKGROUND: Endoscopic third ventriculostomy (ETV) is the treatment of choice for noncommunicating hydrocephalus. In the last decade, its routine use also has taken place in patients who have previously undergone shunt placement (secondary ETV). METHODS: This study reviews the specific anatomy of the ventricular system in patients presenting with shunt malfunction, the criteria for patient selection, and the results of ETV performed as an alternative to shunt revision in cases of shunt malfunction or infection. RESULTS: The success rate of secondary ETV in well-selected cases is not different from that of primary ETV; it should be reasonable to offer all patients with blocked shunts and suitable anatomy indicating an obstructive cause the opportunity for shunt independence regardless of the original cause of the hydrocephalus. CONCLUSIONS: Shunt infection should not be considered a contraindication to ETV, even if the success rate may be lower. Considering the higher complication rate and higher risk of intraoperative failure, secondary ETV should be performed by expert neuroendoscopists.