Superficial siderosis and nonobstructive hydrocephalus due to subependymoma in the ventricle: An illustrative case report

Background: Intraventricular tumors can generally result in obstructive hydrocephalus as they grow. Rarely, however, some intraventricular tumors develop superficial siderosis (SS) and trigger hydrocephalus, even though the tumor has hardly grown. Here, we present an illustrative case of SS and nonocclusive hydrocephalus caused by subependymoma of the lateral ventricles. Case Description: A 78-year-old man with an intraventricular tumor diagnosed 7 years ago had been suffering from gait disturbance for 2 years. He also developed cognitive impairment. Intraventricular tumors showed little growth on annual magnetic resonance imaging (MRI). MRI T2-star weighted images (T2*WI) captured small intratumoral hemorrhages from the beginning of the follow-up. Three years before, at the same time as the onset of ventricular enlargement, T2*WI revealed low intensity in the whole tumor and cerebral surface. Subsequent follow-up revealed that this hemosiderin deposition had spread to the brain stem and cerebellar surface, and the ventricles had expanded further. Cerebrospinal fluid (CSF) examination revealed xanthochromia. The tumor was completely removed en bloc. Histopathological findings were consistent with those of subependymoma. Although CSF findings improved, SS and hydrocephalus did not improve. Therefore, the patient underwent a lumboperitoneal shunt for CSF diversion after tumor resection. Conclusion: Some intraventricular tumors cause SS and nonobstructive hydrocephalus due to microbleeding, even in the absence of tumor growth. T2*WI and, if necessary, timely CSF examination can allow identification of presymptomatic SS. This follow-up strategy may provide a favorable course by facilitating early intervention in patients with intraventricular lesions, not just subependymomas.

Intraoperative sonography in cranial neurosurgery: new possibilities and integration with neuronavigation. Review

In current review we represented new possibilities of intraoperative sonography introduced into clinical practice for the last 20 years. Contrast‑enhanced ultrasound and blood flow imaging (BFI) method are intended for assessment of cerebral hemodynamics. Elastosonography distinguishes tissues by differences of their density. Fusion of sonography with navigation is forwarded to brainshift reduction. Combination of ultrasound with endoscopy is effective in resection of intraventricular tumors and pituitary adenomas. Embedded three‑dimensional sonography is intended to facilitate interpretation of ultrasound results and tailoring craniotomy.

Transcortical approaches to large intraventricular tumors: a prospective case series of 20 patients

Background Large intraventricular tumors (IVTs) impose technical and surgical challenges, due to their enormous sizes, mass effect, vast extensions, and vascularity. Objective The authors aim at presenting their results, clinical outcomes, and the surgical strategies in the management of large IVTs through transcortical approaches. Methods A prospective trial was conducted at the Main Hospital of Alexandria University, Egypt, between August 2018 and October 2020 on 20 patients harboring IVTs larger than 5 cm or bilaterally represented. The variables evaluated included the extent of resection, postoperative neurological deficits, blood loss, surgical approaches, intraoperative challenges, complications, adjuvant therapies, Glasgow Outcome Scale, hydrocephalus, and cerebrospinal fluid (CSF) diversion. Results The study included 20 cases (9 males and 11 females). Mean age at diagnosis was 16.1 years (range 1–45). Mean follow-up was 12 months (range 9–26). Primary tumor locations were ventricular body, atrium, temporal horn, and frontal horn in 11, 5, 3, and 1 cases, respectively. Main pathologies were central neurocytomas (7 patients/35%), ependymomas (3 patients/15%), and subependymal giant cell astrocytoma (SEGA) (3 patients/15%). Excision was gross total (n = 19) and near-total (n = 1). Significant intraoperative bleeding (n = 6). Postoperative minor intraventricular hemorrhage (n = 6), subdural collections (n = 8), hydrocephalus (n = 9), memory affection (n = 4), and motor deficits (n = 4). Postoperative Glasgow Outcome Scale of 5/5 (n = 20), no mortalities were recorded. preoperative seizures (n = 7), new onset postoperative seizures (n = 2). Conclusion Surgical approaches to large tumors of the lateral ventricles should be tailored to the variability of tumor locations, dimensions, extensions, and the individual morbid anatomy, in addition to the surgeon’s experience and preferences. Trans-cortical approaches can provide safe surgical corridors to tackle these challenging subtypes of IVTs with good clinical outcomes, tumor resectability rates, and seizure control.

Rare Case of Young Patient with Intraventricular Angiomatous Meningioma

Pediatric meningiomas are rare and account for only 2.2% of CNS tumors. In this age group, they are more frequently located in atypical sites, such as, mainly, the ventricular system, with a frequency of 8.8 to 13.6%. Adding this to the fact that the angiomatous subtype constitutes only 2.1% of all meningiomas, the rarity of the case reported here i s corroborated. We report a 17-year-old female patient diagnosed with intraventricular angiomatous meningioma; she underwent surgical resection of the tumor in the body and frontal horn of the right lateral ventricle, and there was no neurological sequela. With a follow-up of 4 years, there was no recurrence and the patient had clinical stability. Intraventricular tumors usually have slow growth and reach considerable size until they cause symptoms and then are diagnosed. In addition, the tumor’s deep location and proximity to eloquent areas make such tumors an neurosurgical challenge. The angiomatous subtype, due to the presence of hypervascularization (consisting of more than 50% of vascular components), may, in some cases, hinder surgical resection as well as be erroneously diagnosed. However, surgical treatment aimed at total resection of the lesion remains the conduct of choice in the case reported here, especially in patients in the first two decades of life, in which the use of radiation is avoided. Specifically when it comes to the surgery, we chose a transcallosal approach that allows a good transoperative visualization of the lesion when located in the body and frontal horn of the lateral ventricle.

Endoscopic Management of Intra Ventricular Tumours

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: Seventeen pediatric patients (14 male, 3 female), ages 1-15 years old, underwent surgery via a purely endoscopic approach using a Gaab rigid endoscope and endoscopic ultrasonic aspirator. Ten patients presented with an intraventricular tumor, three with paraventricular, and 4 with suprasellar lesions. Histology analysis showed 6/17 glial tumors, 3/17 with subependymal giant cell astrocytomas (associated with tuberous sclerosis), two cases presented with intraventricular metastases from high-grade tumors (medulloblastoma, atypical teratoid rhabdoid tumor), 4/17 with suprasellar tumors (2 craniopharyngiomas and 2 optic pathway gliomas), and two with pineal region tumors (1 immature teratoma, 1 PNET). In all patients, the endoscopic trajectory and ventricular access were guided by electromagnetic neuronavigation. Fifteen patients underwent surgery via a precoronal bur hole while supine. In 1 case, surgery was performed through a frontal anterior bur hole and 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/Discussion: In 9 cases, the resection was total or near total (more than 90% of lesion removed). In 8 cases, the resection was partial or biopsy. 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. The dry field technique was used in cases with persistence of bleeding. Conclusion: Patients harboring intraventricular tumors are in most cases ideal candidates for endoscopy biopsy/resection. In this 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.

SURG-14. ENDOSCOPIC SURGERY FOR PEDIATRIC INTRAVENTRICULAR TUMOR WITHOUT HYDROCEPHALUS: INDICATION, SURGICAL TECHNIQUE, AVOIDANCE OF COMPLICATION, AND ITS PROSPECT

INTRODUCTION Neuroendoscopic surgery is useful for intraventricular tumors accompanied by ventriculomegaly. However, it is often challenging for cases with small ventricles. Our institution is actively performing surgeries for pediatric intraventricular tumors without frank ventriculomegaly. METHODS Seven cases of intraventricular tumors without ventriculomegaly (5 cases of subependymal giant cell astrocytoma (SEGA) and 2 cases of germ cell tumors (GCTs)) were analyzed. The age ranged between 3 and 14 years (median 5 years). The sizes of SEGA were between 10-27mm, and all the tumors showed an enlargement around the foramen of Monro, which was the indication for surgery. Biopsy and third ventriculostomy were performed for GCTs. For resection, after making a small craniotomy of 2 x 3 cm, ellipse-cone-like sheath with a diameter of 12mm or 17mm was inserted through it to the lateral ventricle, which enabled a wide surgical view. Under a rigid endoscope of 4mm diameter, 2 types of surgical instruments were employed, making the microsurgical procedure like under a microscope, with a wider view, possible. For the cases of tumor resection, septostomy and placement of a drain in the ventricle were performed at the end of surgery. RESULTS The lesions were safely approached in all the cases. For resection, endoscopic microsurgery was possible, and tumor was totally removed in all the cases. No postoperative complication was observed in any of them. CONCLUSIONS Our experience shows that tumor resection can be safely achieved with the aid of endoscope even for cases without ventriculomegaly.

SURG-21. ENDO- AND EXOSCOPIC SURGERY FOR PEDIATRIC NEUROSURGICAL OPERATION

INTRODUCTION Recently endo- and exoscopic surgeries have been gradually performed in neurosurgery. To improve the accuracy and safety of our endoscopic procedures, we are currently trialing 4K or 8K systems. Here we report our experience of endo- and exoscopic procedures for pediatric neurosurgery. METHODS We retrospectively identified 22 patients (15 males, 7 females; mean age, 9.2 years) who underwent surgery for sellar lesions and intraventricular or intraparenchymal lesions with an endo- or exoscopic procedure at our institute between 2010 and 2020. We used a full HD endoscope system (Storz) and an organic electroluminescence (EL) monitor (Sony), and a 4K system (Sony and Olympus). VITOM 3D (Storz) was used as the exoscope. Videoscope (Olympus) was used as a flexible scope for intraventricular tumors. RESULTS We performed surgical procedures as 11 biopsies, 6 third ventriculostomies, 5 resections, and 3 fenestrations. The full HD system with organic EL monitor presented high color contrast. We could easily distinguish between tumor microstructure and the normal structure with the 4K system comparing to full HD. Moreover, electronic zoom function enabled us to discriminate tumor boundaries without having to move the endoscope closer. As a result, we could delineate the surgical working space. VITOM 3D was simple to sharpen the focus on the wider surgical field, similar to the application of an operating microscope. CONCLUSION In pediatric neurosurgery, an endo- or exoscope enables clear visual recognition of a boundary between tumor and normal area.