Dynamic Workflow Proposal for Continuous Frameless Electromagnetic Neuronavigation in Rigid Neuroendoscopy.

BACKGROUND: Ventriculoscopic neuronavigation has been described in several papers. However, there are different ventriculoscopes and navigation systems. Due to these different combinations, it is difficult to find detailed neuronavigation protocols. We describe, step-by-step, a simple method to navigate both the trajectory until reaching the ventricular system, as well as the intraventricular work. METHODS: We use a rigid ventriculoscope (LOTTA, KarlStorz) with an EM-stylet (S8-StealthSystem, Medtronic). The protocol is based on a modified or 3D-printed trocar for navigating the extraventricular step and on a modified pediatric nasogastric tube for the intraventricular navigation. RESULTS: This protocol can be set-up in less than 10 minutes. The extraventricular part is navigated by introducing the EM-stylet inside the modified or 3D-printed trocar. Intraventricular navigation is done by combining a modified pediatric nasogastric tube with the EM-stylet inside the endoscope's working channel. The most critical point is to obtain a blunt-bloodless ventriculostomy while achieving perfect alignment of all targeted structures via pure straight trajectories. CONCLUSIONS: This protocol is easy-to-set-up, avoids head rigid-fixation and bulky optical-based attachments to the ventriculoscope, and allows continuous navigation of both parts of the surgery. Since we have implemented this protocol, we have noticed a significant enhancement in both simple and complex ventriculoscopic procedures because the surgery is dramatically simplified.

Transcortical transcatheter ultrasound-assisted technique for deep-seated brain tumors. Technical note.

PURPOSE: Surgery of deep-seated brain tumors can be challenging. Several methods have been described to facilitate transcortical approaches, including ultrasound-assisted resection. Ultrasound-guided placement of a standard ventricular catheter is a widely reported technique and has been used to approach these lesions via the transcortical route. We describe how we usually perform this useful technique to assist and enhance the transcortical resection of some deep-seated brain tumors. METHODS: Standard electromagnetic frameless navigation (S8 Neuronavigation System, Medtronic, Minneapolis, USA) was employed to focus the craniotomy and to plan the trajectory of the ventricular catheter. After dural opening, an ultrasound device (Arietta 850, Hitachi-Aloka Medical, Tokyo, Japan) was used for intraoperative ultrasound (IOUS) assessment. A ventricular catheter was placed from the cortex to the lateral wall of the tumor under direct real-time IOUS visualization to guide the further transcortical dissection. RESULTS: Transcortical transcatheter ultrasound-assisted technique involved minimal time and infrastructure requirements. There were no major technical difficulties during its use, providing confidence and improving subcortical white matter dissection by guiding the route to the tumor. CONCLUSIONS: Recent improvement of IOUS image-quality devices offers several attractive options for real-time navigation. The combination of conventional neuronavigation systems with real-time IOUS assessment during the intradural step provides a higher degree of control by improving the execution of the surgery. We hope this description may be a useful tool for some selected cases and contribute to the further enhancement and improvement of this widely used technique.

Microsurgical Fenestration of Middle Fossa Arachnoid Cyst in a Pediatric Patient Through a Keyhole Approach with Endoscopic Inspection. 2-Dimensional Operative Video.

In recent decades, the management of middle fossa arachnoid cysts in pediatric patients has evolved significantly through the integration of novel techniques, such as the utilization of endoscopy systems1 and implementation of minimally invasive approaches like keyhole craniotomy.2,3 These cystic formations, occurring within the arachnoid membrane, may lead to neurologic impairments and raised intracranial pressure if left untreated.4 The utilization of endoscopy to aid microsurgical techniques or as a complement to them provides a level of visualization and manipulation of the cyst walls that is significantly more precise than the isolated use of a microscope.1 The keyhole craniotomy allows for reduced surgical trauma, smaller incisions, and quicker recovery times.5 In Video 1, we present the case of a 2-year-old patient with bilateral middle fossa arachnoid cysts exerting mass effect on the adjacent parenchyma. The patient was referred to our institution due to developmental delay and cognitive issues related to language and social interactions. On the basis of imaging findings and clinical correlation, we opted for a microsurgical fenestration with endoscopic inspection using a keyhole craniotomy to minimize complications and enhance the benefits of both techniques. Throughout the surgical video, tricks and considerations that contribute to the combined procedure's efficiency and ease of execution are highlighted and discussed. Postoperative images showed no complications, and the patient was discharged 3 days after surgery.

Endoscopic extended transforaminal approach (medial subchoroid) as an alternative to the classical transchoroidal approach: Technical note.

The extended transforaminal endoscopic approaches allows visualization and manipulation of the middle and posterior third of the III ventricle. In selected cases where the venous anatomy is favorable, the medial subchoroidal approach can be performed as an alternative to the classic transchoroidal approach (via trans-taenia fornicis) with increased protection over the fornix and without the need to sacrifice the septal vein. We present a 14-year-old male with history of Neurofibromatosis type 1 referred for two weeks of clinical evolution with headache, dizziness, gait instability and appearance of a right VI nerve palsy. Magnetic resonance imaging showed obstructive tri-ventricular hydrocephalus due to stenosis of the aqueduct of Sylvius with suspicion of an underlying tumor. An endoscopic surgical procedure was performed through a single approach with III cisternostomy and resection of the tissue that produced the stenosis. The anatomopathological diagnosis showed reactive glial tissue with no signs of malignancy. In conclusion, the medial subchoroidal approach is a plausible alternative in the endoscopic approach to the III ventricle structures in a safe and comfortable manner.

Inflammatory pseudotumor, the great mimicker: A case report.

Inflammatory pseudotumor is a rare lesion, especially at the level of the central nervous system. Its etiology is unknown and the most accepted hypothesis is that it is the consequence of an exaggerated immune response. We present the clinical case of a young Senegalese male, with a history of epilepsy secondary to severe cranioencephalic trauma in childhood, who presented with new epileptic seizures. Imaging tests showed a lesion in the anterior fossa intimately attached to the meninges, so the initial diagnosis was meningioma. A bifrontal craniotomy and microsurgical excision were performed. The definitive anatomopathological analysis concluded that the lesion is an inflammatory pseudotumor whose origin is secondary to a disproportionate reparative process after cranioencephalic trauma.

A silent corticotroph adenoma: making the case for a pars intermedia origin. Illustrative case.

BACKGROUND: Silent corticotroph adenomas (SCAs) are the only pituitary adenomas thought to originate from the pars intermedia. This case report presents the rare finding of a multimicrocystic corticotroph macroadenoma displacing the anterior and posterior lobes of the pituitary gland on magnetic resonance imaging (MRI). This finding supports the hypothesis that silent corticotroph adenomas may originate from the pars intermedia and should be considered in the differential for tumors arising from this location. OBSERVATIONS: A 55-year-old man presented with an episode of confusion and blurred vision. MRI demonstrated separation of the anterior and posterior glands by a solid-cystic lesion located within the pars intermedia that superiorly displaced the optic chiasm. Endocrinologic evaluation was unremarkable. The differential diagnosis included pituitary adenoma, Rathke cleft cyst, and craniopharyngioma. The tumor was confirmed to be an SCA on pathology and was completely removed through the endoscopic endonasal transsphenoidal approach. LESSONS: The case highlights the importance of preoperative screening for subclinical hypercortisolism for tumors arising from this location. Knowledge of a patient's preoperative functional status is critical and dictates their postoperative biochemical assessment to determine remission. The case also illustrates surgical strategies for resecting pars intermedia lesions without injuring the gland.

Spontaneous rhinorrhea: a possible concealing initial symptom of ecchordosis physaliphora. Illustrative case.

BACKGROUND: Spontaneous rhinorrhea may be the initial manifestation of ecchordosis physaliphora (EP). There are currently 47 published cases of symptomatic EP, with spontaneous rhinorrhea being one of the most prevalent symptoms. The authors report 1 case as a cause of cerebrospinal fluid (CSF) fistula. OBSERVATIONS: A 46-year-old woman presented to the authors' clinic with meningitis secondary to nasal CSF leakage. The computed tomography (CT) scan indicated an imperceptibly thin/dehiscent focus along the posterior wall of the sphenoid air cell's midline. A tumor was identified during endoscopic endonasal CSF repair surgery. EP was diagnosed in the frozen and final pathology. LESSONS: EP should be considered as a potential cause of spontaneous rhinorrhea. This initial clinical manifestation accounts for 35% of symptomatic EP cases. The prepontine and posterior sphenoid sinus wall appear to be the locations with the highest susceptibility. Surgical therapy of the fistula without excision of the lesion may result in insufficient issue resolution and recurrence.

Feasibility of extended transforaminal approach (medial subchoroid) for resection of a benign aqueductal tumor in a patient with type 1 neurofibromatosis.

The extended transforaminal endoscopic approach allows visualization and manipulation of the third ventricle posterior structures in a safe and comfortable manner. The medial subchoroidal approach has been described as a feasible alternative to the classical transchoroidal approach. In this video, the authors present the case of a 14-year-old male with a history of neurofibromatosis type 1 who was referred to our department after presenting with headaches and diplopia for 2 weeks. Suspecting an aqueduct tumor, the authors performed an endoscopic surgical procedure through a single approach with third cisternostomy and resection of the tumor that produced the stenosis. The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22155.

Intraoperative ultrasound-assisted surgery in orbital apex tumours: technical note.

BACKGROUND: Since the introduction of ultrasonography (US) in the operating theatre in the early 1970s, intraoperative ultrasound (IOUS) has become a very useful tool for real-time neurosurgical procedures. The main limitation of US is its innately reduced capacity to penetrate the intact skull. This is the reason why most IOUS-assisted procedures are usually performed via transfontanellar or after a craniotomy or laminotomy is done. OBJECTIVE: We present a 54-year-old woman with a right optic nerve sheath meningioma, who was operated on by a right cranio-orbital approach and IOUS-assisted tumour removal. METHODS: Data concerning the anamnesis and complementary studies were obtained from the clinical history. Surgical images were obtained in the operating room during surgery. Images obtained by US were compared with the preoperative and postoperative imaging scans. IOUS imaging was also compared with the intraoperative findings. RESULTS: The correlation between US and both preoperative and postoperative studies was very high. During surgery, both transpalpebral and transperiorbital IOUS facilitated the resection with no specific technical difficulties or significant time consumption. CONCLUSION: Recent improvements in the image quality of IOUS devices offer several attractive options for real-time neuronavigation. We describe our initial experience with the IOUS-assisted technique for orbital apex tumours. In our patient transpalpebral and transperiorbital IOUS provided an excellent source of control over location and over the extent of tumour resection. We hope that this description of how we usually perform this procedure may be useful for some selected cases and contribute to the further enhancement and improvement of the technique.

Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: a nationwide study in Spain.

OBJECTIVE: To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. SETTINGS: The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. PARTICIPANTS: This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. INTERVENTIONS: An exploratory factorial analysis was performed to select the most relevant variables of the sample. PRIMARY AND SECONDARY OUTCOME MEASURES: Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. RESULTS: Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/105 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade ≥3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/105 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. CONCLUSIONS: Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/105 people/week) was a statistically independent predictor of mortality. TRIAL REGISTRATION NUMBER: CEIM 20/217.

Sincronía de diferentes tumores radioinducidos en superviviente de leucemia linfoblástica aguda / Different radioinducid tumors synchrony in an acute lymphoblastic leukemia survivor

La aparición de tumores craneales inducidos por radiación en pacientes pediátricos tratados de enfermedades hematológicas como la leucemia/linfoma linfoblástico T (T-ALL/LBL) es un fenómeno conocido que puede incluir lesiones de diferentes grados de malignidad y precisar tratamiento neuroquirúrgico. Presentamos el caso de un varón de 38 años remitido a nuestro servicio por la aparición brusca de diplopía con hemiparesia izquierda progresiva de 6 meses de evolución y caídas frecuentes. Tras realización de pruebas de imagen, se objetivan distintas lesiones intraaxiales y extraaxiales con diferente comportamiento radiológico decidiéndose un abordaje quirúrgico único para su exéresis. La anatomía patológica confirma cuatro variantes histológicas: meningioma (grado 1 y 2 [atípico]), subependimoma y cavernoma. Discutimos el papel teratogénico y efectos biológicos de las radiaciones ionizantes (AU)

The cranial radiation-induced tumors appearance in pediatric patients treated for hematological diseases such as leukemia/T-lymphoblastic lymphoma (T-ALL/LBL) is a known phenomenon that may include lesions of different malignant degrees and require neurosurgical treatment. We present the case of a 38-year-old man referred to our department for a sudden diplopia with 6-month progressive left hemiparesis and frequent falls. After imaging tests, different intra and extraxial lesions with different radiological behavior were observed, performing a single surgical approach for their resection. The pathological anatomy confirms four histological variants: meningioma (grade 1 and 2 [atypical]), subependymoma, and cavernoma. We discuss the teratogenic role of ionizing radiation (AU)

Microsurgical training: vascular control and intraoperative vessel rupture in the human placenta infusion model.

BACKGROUND: Microsurgery is a challenging discipline. Regular lab training under the operating microscope has been the environment where most surgeons have mastered the skills and techniques inherent to most microneurosurgical procedures. However, some critical scenarios remain difficult to master or simulate. We describe a step-by-step method for how to build a low-cost, feasible, and widely available model that allows residents to familiarize themselves with demanding critical situations such as intraoperative rupture of major vessels. METHODS: After delivery, nine fresh human placentas were transferred to the lab. The umbilical vein was cannulated for normal saline infusion. Several hands-on procedures were performed under direct microscope vision. Operating microscope setup, allantoic membrane splitting, vascular dissection and vessel injury, and repair exercises were simulated and video recorded. Indocyanine green was administered to simulate intraoperative angiography. RESULTS: The model can be setup in less than 15 min, with minimal cost and infrastructure requirements. All the exercises described above can be conducted with a single placenta. Umbilical vein cannulation adds realism and allows quantification of the volume of saline required to complete the exercise. The final check with indocyanine green simulates intraoperative angiography and allows the assessment of distal vessel patency. CONCLUSIONS: Minimal infrastructure requirements, simplicity, and easy setup models provide a suitable environment for regular training. The human placenta is inexpensive and widely available, making it a feasible model for residents training. Neurosurgery residents may benefit from this model to familiarize with microsurgery and critical scenarios in a risk-free environment without time or resource constraints.

Neuroendoscopic training in neurosurgery: a simple and feasible model for neurosurgical education.

BACKGROUND: The development of high levels of technical competence and excellent decision-making skills are key goals of all neurosurgical residency training programs. This acquisition of technical skills is becoming increasingly difficult due to many factors including less exposure to operative cases, demand for more time and cost-effective practices, and resident work hour restrictions. We describe a step-by-step method for how to build a low-cost and feasible model that allows residents to improve their neuroendoscopic skills. METHODS: The bell pepper-based model was developed as an endoscopic training model. Using continuous irrigation, several hands-on procedures were proposed under direct endoscopic visualization. Endoscope setup, endoscopic third ventriculostomy, septostomy, and tumor biopsy procedures were simulated and video recorded for further edition and analysis. RESULTS: The model can be setup in less than 15 min with minimal cost and infrastructure requirements. A single model allows simulation of all the exercises described above. The model allows exposure to the camera skills, instrument handling, and hand-eye coordination inherent to most neuroendoscopic procedures. CONCLUSION: Minimal infrastructure requirements, simplicity, and easily setup models provide a proper environment for regular training. The bell pepper-based model is inexpensive, widely available, and a feasible model for routine training. Neurosurgery residents may benefit from the use of this model to accelerate their learning curve and familiarize themselves with the neuroendoscopic core principles in a risk-free environment without time or resource constraints.

Hemorragia subaracnoidea masiva durante la embolización de una malformación arterovenosa espinal de tipo iv. Complicación del tratamiento endovascular / Massive subarachnoid hemorrhage during type iv spinal arteriovenous malformation embolization. An endovascular procedure complication

Las malformaciones arteriovenosas espinales constituyen una entidad con una baja prevalencia y un diagnóstico en ocasiones complejo que precisa la colaboración de diferentes especialidades médicas. El abordaje multidisciplinar requiere una comunicación fluida entre servicios, ambiente laboral favorable y unas relaciones sociales correctas que traten de evitar la aparición de conflictos de intereses. Presentamos el caso de una mujer de 31 años remitida a nuestro departamento con una paraparesia asimétrica progresiva de 10 meses de evolución y disfunción vesical ocasional. Con el diagnóstico de malformación arteriovenosa espinal de tipo IV, se realizó una embolización programada tras la que se produjo una hemorragia subaracnoidea masiva debido a la laceración de la arteria espinal anterior que precisó una craniectomía bifrontal urgente. Discutimos el papel del neurocirujano en el tratamiento de las complicaciones derivadas del tratamiento endovascular de la patología espinal (AU)

Spinal arteriovenous malformations are rare diseases with a low prevalence and a complex diagnosis that usually requires the several neuroscience disciplines collaboration. Multidisciplinary approach requires fluid communication, favorable work environment and a correct social relationship, thus avoiding the conflict of interest appearance. We reported a 31 years old female referred to our department with progressive asymmetric spastic paraparesia for 10 months of evolution and occasional bladder dysfunction. With the diagnosis of a type IV arteriovenous malformation, a scheduled embolization was performed resulting in a massive subarachnoid hemorrhage due to the ASA laceration requiring an emergency bifrontal craniectomy. We discuss the neurosurgeońs role in complications during endovascular spinal vascular pathology treatment (AU)

Rotation flap closure of a giant dorsolumbar myelomeningocele: technical note.

PURPOSE: Myelomeningocele (MMC) is the most prevalent form of spina bifida aperta. Here we present the surgical repair technique of a dorsolumbar myelomeningocele with a large associated soft tissue defect. METHODS: Data concerning the anamnesis and complementary studies were obtained from the clinical history. Surgical images were obtained in the operation room during surgery. RESULT: We describe the case of a newborn with a dorsal myelomeningocele with a placode in the central area and a large associated skin defect of 12 x× 12 cm. Urgent intervention was carried out on the day of birth with placode reconstruction. Dorsal and gluteus maximus muscle rotation and skin rotation flap were performed in order to achieve complete closure of the myocutaneous defect. The patient presented a good recovery with no new neurological deficit. CONCLUSION: Myelomeningocele may be associated with large myocutaneous defects that can be difficult to correct by primary closure. In these cases, rotation flaps may be necessary to achieve complete closure.

Massive subarachnoid hemorrhage during type iv spinal arteriovenous malformation embolization. An endovascular procedure complication. / Hemorragia subaracnoidea masiva durante la embolización de una malformación arterovenosa espinal de tipo iv. Complicación del tratamiento endovascular.

Spinal arteriovenous malformations are rare diseases with a low prevalence and a complex diagnosis that usually requires the several neuroscience disciplines collaboration. Multidisciplinary approach requires fluid communication, favorable work environment and a correct social relationship, thus avoiding the conflict of interest appearance. We reported a 31 years old female referred to our department with progressive asymmetric spastic paraparesia for 10 months of evolution and occasional bladder dysfunction. With the diagnosis of a type IV arteriovenous malformation, a scheduled embolization was performed resulting in a massive subarachnoid hemorrhage due to the ASA laceration requiring an emergency bifrontal craniectomy. We discuss the neurosurgeons role in complications during endovascular spinal vascular pathology treatment.

Different radioinducid tumors synchrony in an acute lymphoblastic leukemia survivor. / Sincronía de diferentes tumores radioinducidos en superviviente de leucemia linfoblástica aguda.

The cranial radiation-induced tumors appearance in pediatric patients treated for hematological diseases such as leukemia/T-lymphoblastic lymphoma (T-ALL/LBL) is a known phenomenon that may include lesions of different malignant degrees and require neurosurgical treatment. We present the case of a 38-year-old man referred to our department for a sudden diplopia with 6-month progressive left hemiparesis and frequent falls. After imaging tests, different intra and extraxial lesions with different radiological behavior were observed, performing a single surgical approach for their resection. The pathological anatomy confirms four histological variants: meningioma (grade 1 and 2 [atypical]), subependymoma, and cavernoma. We discuss the teratogenic role of ionizing radiation.