Pediatric neurosurgery training during residency in Switzerland and the need for dedicated subspecialization training

INTRODUCTION

Pediatric Neurosurgery as a subspeciality started to emerge during the late 1950s, with only a few dedicated pediatric neurosurgeons in the Western world. Over the last few decades, the awareness that children require subspecialized care by dedicated pediatric neurosurgeons and an interdisciplinary team has been growing worldwide, leading to an increase in pediatric neurosurgeons. Several studies have shown that subspecialized care for pediatric patients improves outcomes and is cost-effective. This survey aims to assess the current setting of pediatric neurosurgery and training of neurosurgical residents in pediatric neurosurgery in Switzerland.

METHODS

We conducted an online survey by sending e-mail invitations in 2021 to all neurosurgical residents in Switzerland. The survey included questions regarding the participants' demographics, current workplace structures, the care of specific pediatric neurosurgical pathologies, and participants' opinions of the Swiss training program for pediatric neurosurgery and possible improvement. We defined at the beginning of the survey that a pediatric neurosurgeon is a board-certified neurosurgeon with at least one year of dedicated pediatric neurosurgical fellowship training abroad.

RESULTS

We received a total of 25 responses from residents, of which 20 (80%) were male. Twenty-two participants (88%) worked in one of seven major hospitals in Switzerland at the time of the survey, and four (16%) were interested in pursuing a fellowship in pediatric neurosurgery. Seven (35%) and five residents (25%) feel comfortable taking care on the ward of a craniosynostosis and hydrocephalus patient younger than 6 months, respectively. Twelve residents (60%) feel comfortable taking care of a pediatric brain tumor patient. The majority (n = 22, 88%) of all residents agree that a fellowship-trained pediatric neurosurgeon should treat children, while two (8%) residents state that any neurosurgeon with an interest in pediatric neurosurgery should be able to treat children. All residents (n = 25, 100%) agree that pediatric neurosurgery training and care in Switzerland needs to be improved.

CONCLUSION

Pediatric neurosurgery training in Switzerland is rather heterogeneous and not very well structured, with varying frequencies of children-specific neurosurgical pathologies. Most residents agreed that a subspecialized pediatric neurosurgeon should oversee the care of children in neurosurgery, while all agree that pediatric neurosurgical training and care should be improved in Switzerland.

Patient- and Caregiver-Reported Outcome Measures after Single-Level Selective Dorsal Rhizotomy in Pediatric and Young Adult Patients with Spastic Cerebral Palsy

INTRODUCTION

The aim of this cohort study was to assess the outcome of single-level selective dorsal rhizotomy (SDR) in children and young adults with spastic cerebral palsy (CP) treated at our institution, focusing on patient-reported outcome measures (PROMs) and quality of life (QoL) of patients and their caregivers.

METHODS

We included consecutive patients undergoing SDR from 2018 to 2020 at our institution. Subjective outcome was measured through PROMs, while functional outcome was measured through baseline characteristics, operative outcome, as well as short- and long-term follow-up. Furthermore, the effect of age at the time of surgery on patient/caregiver satisfaction was analyzed.

RESULTS

Seven patients (3 female, 43%) with a median age at surgery of 11.9 years (IQR 8.7-15.5) were included. All patients had a Gross Motor Function Classification (GMFCS) score of at least IV before surgery. Five surgeries were palliative and two non-palliative. Based on PROMs, SDR showed very good QoL and health-related outcome measures for both palliative and non-palliative patients. Patient/caregiver satisfaction was higher for the early subgroup (age ≤11) than the late subgroup (age >11). Functional outcome showed reduced spasticity in both groups. Blood transfusions were never needed, while no cerebrospinal fluid leak, infection, or permanent morbidity was seen.

CONCLUSION

Based on PROMs, SDR leads to high satisfaction and improved QoL, especially if done at an early age. Further studies with larger cohorts are necessary to underline and confirm our observations.

Wound closure with a mesh and liquid tissue adhesive (Dermabond Prineo) system in pediatric spine surgery: a prospective single-center cohort study incorporating parent-reported outcome measures

OBJECTIVE

Wound healing can be challenging in children undergoing spine surgery for neurological conditions due to a high risk of cerebrospinal fluid (CSF) leakage and wound infection. In adults, use of the Dermabond Prineo (DP) skin closure system, which consists of both tissue adhesive glue and a self-adhesive mesh, for wound closure of medium-length surgical incisions has been reported. The aim of this study was to investigate the efficiency and cosmetic outcome of DP for wound closure in extra- and intradural pediatric neurological spine surgery.

METHODS

In this prospective cohort study, 47 children underwent 50 spine procedures using DP for wound closure between 2018 and 2022 at a single institution. Patient demographic and surgical data were collected. The primary outcome was revision surgery for wound healing disorders, while secondary outcomes were infections, minor wound healing disorders, and both physician and parental satisfaction (parent-reported outcome measures [PROMs]) at last follow-up.

RESULTS

Among 50 spinal (45 intra- and 5 extradural) interventions, 1 patient (2%) underwent revision surgery for a cutaneous CSF fistula and pseudomeningocele. Minor wound healing disorders occurred after 16 surgeries, which did not require surgical wound revision and resolved completely. No allergic reactions to DP or surgical site infections within 30 days were observed. The parents and the medical team described wound care as significantly facilitated since wound dressing changes were not needed. Three families (6.4%) encountered difficulties in wound care, and 46 (97.9%) were satisfied with DP. The cosmetic outcome based on PROMs was excellent, with a mean score of 8 (IQR 2) on a scale from 1 to 10. At long-term follow-up, a mean of 11.3 ± 10.7 months after surgery, physicians rated the cosmetic outcome on the visual analog scale (median score 9, IQR 1) and Hollander scale (median score 6, IQR 1). The outcomes were similar among the different pathologies and age groups and did not differ in patients with and without syndromic malformations.

CONCLUSIONS

The application of DP is simple, enables good patient comfort, facilitates both professional and parental wound care, and leads to excellent cosmetic results. DP possibly aids in the reduction of postoperative CSF leakage and infections after pediatric neurological spine surgery.

Minimal invasive interlaminar approach for untethering of fatty filum terminale in pediatric patients - how I do it

BACKGROUND

Fatty filum terminale is a form of spinal dysraphism and a third of all patients develop symptoms such as sensory, motor, and urinary impairment. Early surgery at 6 months has the advantage that the bone density is still soft, and the patients are not ambulatory yet, promoting faster healing.

METHOD

We present our minimal invasive surgical technique for FFT untethering.

CONCLUSION

Due to the low complication rate and the potentially high benefit of surgery, prophylactic untethering is recommended.

CSF shunting in myelomeningocele-related hydrocephalus and the role of prenatal imaging

OBJECTIVE

Hydrocephalus is commonly associated with myelomeningocele (MMC). Indication and timing of cerebrospinal fluid (CSF) shunting are still a topic of discussion. The aim of this study was to investigate whether the analysis of prenatal cerebral imaging studies could provide information that is predictive of the necessity of CSF shunting in the postnatal period.

MATERIAL AND METHODS

Among 73 infants operated on because of MMC between January 2003 and June 2020, 50 had undergone prenatal and postnatal MRI studies and were considered for analysis. For each patient, frontal horn width, atrial ventricle diameter, third ventricle diameter, and subarachnoid spaces (sinocortical width, craniocortical width, and the interhemispheric width) have been measured on prenatal, postnatal, and a follow-up MRI study. The need of CSF shunting device placement in relation to prenatal and early postnatal MRI data was investigated.

RESULTS

Of the 50 infants, 31 (62%) developed a progressive hydrocephalus. Of these, 30 needed a CSF shunt and the majority of them (n=29) was operated on within 28 days after birth. One patient needed CSF shunt implantation at 45 days after birth and one child developed a late progressive hydrocephalus, successfully treated by ETV alone, at 14.2 months of age. All patients with an atrial ventricle diameter greater than 1.9 cm and a 3rd ventricle diameter larger than 0.3 cm on antenatal third trimester imaging have undergone CSF shunting within 1 month after birth. Conversely, all the children that did not undergo a CSF shunt placement showed an atrial cerebral ventricle diameter inferior to 1.2 cm and a 3rd ventricle width < 0.3 cm on antenatal imaging. Frontal horn width and subarachnoid CSF spaces' evolution did not seem to play a role.

CONCLUSION

The prenatal MRI assessment of the associated prenatal ventriculomegaly in MMC provides parameters that have a predictive value heralding the probability of a CSF diversion procedure after birth. In the same way, the analysis of intrauterine MRI studies may identify those subjects that are less at risk of developing a progressive hydrocephalus after birth, therefore encouraging a more cautious attitude towards the early implantation of CSF shunting devices in the current clinical practice.

Fixed posterior cranial vault expansion technique

BACKGROUND

Different techniques to reshape the posterior skull vault have been developed in the last decades, all sharing the same goals of increasing the skull volume, decreasing the intracranial pressure (ICP), correcting the cranial dysmorphy, and contributing to a better growth of the skull. Though over the last years most refinements in these techniques have focused on the use of hardware as distractors or springs, the fixed posterior vault expansion remains a valuable procedure for cranial remodeling.

METHODS

We describe in details the technique used for fixed posterior vault expansion in children that is applied at the French Referral center for Craniosynostosis of Lyon, France.

DISCUSSION

The fixed posterior vault expansion increases the risk of perioperative complications due to the elevation of the posterior bone flap from the dura but allows an immediate decompression and correction of the shape, simplifying the postoperative course.

Metopic triangle osteotomy in trigonocephaly Piezosurgery: a technical variant to control metopic emissary veins

Premature fusion of the metopic suture results in trigonocephaly with variable degrees of anterior cranial fossa dysmorphia and craniofacial deformity. Different surgical corrective techniques that aim to reshape the forehead and enlarge the cranial volume have been described. Typical variations of the standard fronto-orbitary advancement carry the risk of relevant blood loss during frontal osteotomy, where paired emissary metopic veins are disrupted. The authors present a technical variant that preserves a bony triangle over the glabella to optimize control of these veins, which represent the major source of bleeding, and applies Piezosurgery to perform the osteotomies to minimize bone substance loss.

The video can be found here: https://vimeo.com/511536423.

Maternal and obstetric complications in fetal surgery for prenatal myelomeningocele repair: a systematic review

OBJECTIVE

Comparing prenatal and postnatal surgical repair techniques for myelomeningocele (MMC), in utero fetal surgery has increasingly gained acceptance and is considered by many specialized centers the first choice of treatment. Despite its benefits, as demonstrated in the Management of Myelomeningocele Study (MOMS), including reduced need for CSF shunting in neonates and improved motor outcomes at 30 months, there is still an ongoing debate on fetal and maternal risks associated with the procedure. Prenatal open hysterotomy, fetoscopic MMC repair techniques, and subsequent delivery by cesarean section are associated with maternal complications. The aim of this systematic review is to assess the available literature on maternal and obstetric complication rates and perinatal maternal outcomes related to fetal MMC repair.

METHODS

The authors identified references for inclusion in this review by searching PubMed and MEDLINE, with restrictions to English language, case series, case reports, clinical trials, controlled clinical trials, meta-analyses, randomized controlled trials, reviews, and systematic reviews. The rate of maternal and obstetric complications was analyzed based on studies focusing on this issue and presenting clear results on the matter.

RESULTS

Of 1264 articles screened, 36 were included in this systemic review, whereof 11 were eligible for data analysis and comparison. The average overall rate of maternal and obstetric complications corresponds to 78.6%. The majority of the described events are obstetric complications, varying from chorioamniotic membrane separation in 65.6% of cases, oligohydramnios in 13.0% of cases, placental abruption in 5.0% of cases, spontaneous or preterm premature membrane rupture in 42.0% of cases, and early preterm delivery in 11.3% of cases due to uterine dehiscence, occurring in 0.9% of cases. The most common medical complications are development of pulmonary edema occurring in 2.8%, gestational diabetes in 3.7%, gestational hypertension/preeclampsia in 3.7%, and need for blood transfusions in 3.2% of cases. Limitations of the review arise from the lack of data in the current literature, with maternal and obstetric complications being underreported.

CONCLUSIONS

Although the efforts of further advancement of intrauterine prenatal MMC repair aim to increase neonatal outcomes, maternal health hazard will continue to be an issue of crucial importance and further studies are required.

Development and validation of a synthetic 3D-printed simulator for training in neuroendoscopic ventricular lesion removal

OBJECTIVE

Neuroendoscopic surgery using an ultrasonic aspirator represents a valid tool with which to perform the safe resection of deep-seated ventricular lesions, but the handling of neuroendoscopic instruments is technically challenging, requiring extensive training to achieve a steep learning curve. Simulation-based methods are increasingly used to improve surgical skills, allowing neurosurgical trainees to practice in a risk-free, reproducible environment. The authors introduce a synthetic, patient-specific simulator that enables trainees to develop skills for endoscopic ventricular tumor removal, and they evaluate the model’s validity as a training instrument with regard to realism, mechanical proprieties, procedural content, and handling.

METHODS

The authors developed a synthetic simulator based on a patient-specific CT data set. The anatomical features were segmented, and several realistic 1:1 skull models with all relevant ventricular structures were fabricated by a 3D printer. Vascular structures and the choroid plexus were included. A tumor model, composed of polyvinyl alcohol, mimicking a soft-consistency lesion, was secured in different spots of the frontal horn and within the third ventricle. Neurosurgical trainees participating in a neuroendoscopic workshop qualitatively assessed, by means of a feedback survey, the properties of the simulator as a training model that teaches neuroendoscopic ultrasonic ventricular tumor surgery; the trainees rated 10 items according to a 5-point Likert scale.

RESULTS

Participants appreciated the model as a valid hands-on training tool for neuroendoscopic ultrasonic aspirator tumor removal, highly rating the procedural content. Furthermore, they mostly agreed on its comparably realistic anatomical and mechanical properties. By the model’s first application, the authors were able to recognize possible improvement measures, such as the development of different tumor model textures and the possibility, for the user, of creating a realistic surgical skull approach and neuroendoscopic trajectory.

CONCLUSIONS

A low-cost, patient-specific, reusable 3D-printed simulator for the training of neuroendoscopic ultrasonic aspirator tumor removal was successfully developed. The simulator is a useful tool for teaching neuroendoscopic techniques and provides support in the development of the required surgical skills.

Neuronal Mitochondrial Dysfunction Activates the Integrated Stress Response to Induce Fibroblast Growth Factor 21

Stress adaptation is essential for neuronal health. While the fundamental role of mitochondria in neuronal development has been demonstrated, it is still not clear how adult neurons respond to alterations in mitochondrial function and how neurons sense, signal, and respond to dysfunction of mitochondria and their interacting organelles. Here, we show that neuron-specific, inducible in vivo ablation of the mitochondrial fission protein Drp1 causes ER stress, resulting in activation of the integrated stress response to culminate in neuronal expression of the cytokine Fgf21. Neuron-derived Fgf21 induction occurs also in murine models of tauopathy and prion disease, highlighting the potential of this cytokine as an early biomarker for latent neurodegenerative conditions.

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Neuronal Drp1 ablation is sensed by branches of the integrated stress response (ISR)

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Activation of the ISR induces catabolic cytokine Fgf21 in the brain

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Brain Fgf21 induced in neurodegeneration models may be a potential biomarker

Frontoethmoidal Osteoma with Secondary Intradural Mucocele Extension Causing Frontal Lobe Syndrome and Pneumocephalus: Case Report and Review of Literature

BACKGROUND

Paranasal sinus osteoma is a common, asymptomatic, histologically benign, slow-growing tumor. However, it can give rise to secondary pathologies such as a mucocele in about 50% of the cases. Rarely, intracranial and orbital extension is present, leading to rhinoliquorrhea, pneumocephalus, or neurologic and visual impairment, which might be potentially life-threatening.

CASE DESCRIPTION

A 49-year-old man presented with an acute frontal lobe syndrome and rhinoliquorrhea. Cranial magnetic resonance tomography showed a suspected frontoethmoidal osteoma with a mucocele expanding intradurally into the left frontal lobe. It was accompanied by pneumocephalus and showed communication with the left lateral ventricle. Through a bifrontal craniotomy, in toto resection of the frontoethmoidal bony tumor and the intradural mucocele was performed, while thereafter the frontal sinus was cranialized using a pedunculated periosteal flap. Postoperative recovery was uneventful with complete resolution of the tension pneumocephalus and rhinoliquorrhea and led to an improvement of the frontal lobe syndrome.

CONCLUSIONS

We present a rare case of pneumocephalus caused by a frontoethmoidal osteoma associated with an intradural mucocele. A review of the literature, focusing on the surgical strategies in such cases, is provided.

DRP1-dependent apoptotic mitochondrial fission occurs independently of BAX, BAK and APAF1 to amplify cell death by BID and oxidative stress

During apoptosis mitochondria undergo cristae remodeling and fragmentation, but how the latter relates to outer membrane permeabilization and downstream caspase activation is unclear. Here we show that the mitochondrial fission protein Dynamin Related Protein (Drp) 1 participates in cytochrome c release by selected intrinsic death stimuli. While Bax, Bak double deficient (DKO) and Apaf1(-/-) mouse embryonic fibroblasts (MEFs) were less susceptible to apoptosis by Bcl-2 family member BID, H(2)O(2), staurosporine and thapsigargin, Drp1(-/-) MEFs were protected only from BID and H(2)O(2). Resistance to cell death of Drp1(-/-) and DKO MEFs correlated with blunted cytochrome c release, whereas mitochondrial fragmentation occurred in all cell lines in response to all tested stimuli, indicating that other mechanisms accounted for the reduced cytochrome c release. Indeed, cristae remodeling was reduced in Drp1(-/-) cells, potentially explaining their resistance to apoptosis. Our results indicate that caspase-independent mitochondrial fission and Drp1-dependent cristae remodeling amplify apoptosis. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.

Less than perfect divorces: dysregulated mitochondrial fission and neurodegeneration

Research efforts during the last decade have deciphered the basic molecular mechanisms governing mitochondrial fusion and fission. We now know that in mammalian cells mitochondrial fission is mediated by the large GTPase dynamin-related protein 1 (Drp1) acting in concert with outer mitochondrial membrane (OMM) proteins such as Fis1, Mff, and Mief1. It is also generally accepted that organelle fusion depends on the action of three large GTPases: mitofusins (Mfn1, Mfn2) mediating membrane fusion on the OMM level, and Opa1 which is essential for inner mitochondrial membrane fusion. Significantly, mutations in Drp1, Mfn2, and Opa1 have causally been linked to neurodegenerative conditions. Despite this knowledge, crucial questions such as to how fission of the inner and outer mitochondrial membranes are coordinated and how these processes are integrated into basic physiological processes such as apoptosis and autophagy remain to be answered in detail. In this review, we will focus on what is currently known about the mechanism of mitochondrial fission and explore the pathophysiological consequences of dysregulated organelle fission with a special focus on neurodegenerative conditions, including Alzheimer's, Huntington's and Parkinson's disease, as well as ischemic brain damage.