Long-Term Success of Endoscopic Third Ventriculostomy in the Pediatric Population with Aqueductal Stenosis.

OBJECTIVE: To evaluate the long-term success rate of endoscopic third ventriculostomy (ETV) in the treatment of hydrocephalus due to aqueductal stenosis in the pediatric population. METHODS: Between January 2007 and June 2023, a total of 82 children underwent ETV surgery for hydrocephalus and met the inclusion criteria for our study. The children's medical records were reviewed, and cases requiring additional surgery in the months and years following surgery for ventriculostomy failure were reviewed. RESULTS: The mean age was 5.35 years. Successful ETV was observed in 74 children with a successful ETV rate of 90%. The median follow-up was 6.75 years (2 months-15.5 years). Eight children (10%) underwent additional surgery. In 7 cases, additional surgery was performed within 3 months, while in the remaining case, a delayed failure was noted (more than 3 years later). At 6 months and 3 years, the cumulative proportion of children with revision-free survival was 91%, declining slightly to 89% at 5 years. CONCLUSIONS: ETV is highly effective in treating hydrocephalus in pediatric patients with aqueductal stenosis, with a 91% success rate at 6 months and 3 years. Although the success rate drops slightly to 89% at 5 years, it still demonstrates durability. Late failures are usually characterized by symptoms of increased intracranial pressure. While patients with a confirmed successful ETV at 6 months may be considered for reduced follow-up frequency, it is critical to educate them about the symptoms of intracranial hypertension and the importance of seeking medical attention promptly if such symptoms occur.

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

BACKGROUND: Ventriculoscopic neuronavigation has been described in several articles. 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 electromagnetic stylet (S8-StealthSystem, Medtronic). The protocol is based on a modified or 3-dimensionally 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 electromagnetic stylet inside the modified or 3-dimensionally printed trocar. Intraventricular navigation is done by combining a modified pediatric nasogastric tube with the electromagnetic 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.

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.

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.