Optochiasmatic cavernoma: Surgical treatment and outcomes.

OBJECTIVE: Optochiasmatic cavernoma is an extremely rare cerebral lesion. They account for approximately 1% of all cavernomas of the central nervous system. Reports on this pathology are limited. Abrupt visual deterioration is a common symptom of the disease. Treatment strategy and visual outcomes after different treatment approaches remain a subject for discussion. METHODS: Patients operated in a period 2005-2021 were analyzed in this study. All patients preoperatively underwent computed tomography (CT) scan, CT-angiography, and magnetic resonance imaging (MRI). Visual function of the patients was assessed pre-op, post-op and at the follow-up. Duration of visual dysfunction was noted as well. Surgical details were also extracted from medical notes. All patients were followed up, and control MRI was performed one month after operation. We assessed surgical series of optochiasmatic cavernomas published for last 10 years. Further comparative analysis with our data was performed. RESULTS: Five patients were included into this study. There were four men and one woman. Mean age comprised 33.8 years (range 20-48 years). Most patients were admitted to our hospital due to visual disturbances (80%). Visual function improved in four patients. Visual function was unchanged in one patient, lacking visual disturbancies pre-op. Complication developed in one patient. CONCLUSIONS: Optochiasmatic cavernomas are encountered extremely rare. Despite the use of contemporary diagnostic options, differential diagnosis remains challenging. Full diagnostic work-up is mandatory. After the diagnosis is made, surgical treatment should be considered first. Total microsurgical or endoscopic transsphenoidal removal of the optochiasmatic cavernoma is a relatively safe and effective treatment method facilitating improvement of visual function.

Internal Carotid Artery Injury in Transsphenoidal Surgery: Tenets for Its Avoidance and Refit-A Clinical Study.

One of the most serious/potentially fatal complications of transsphenoidal surgery (TSS) is internal carotid artery (ICA) injury. Of 6230 patients who underwent TSS, ICA injury occurred in 8 (0.12%). The etiology, possible treatment options, and avoidance of ICA injury were analyzed. ICA injury occurred at two different stages: (1) during the exposure of the sella floor and dural incision over the sella and cavernous sinus and (2) during the resection of the cavernous sinus extension of the tumor. The angiographic collateral blood supply was categorized as good, sufficient, and nonsufficient to help with the decision making for repairing the injury. ICA occlusion with a balloon was performed at the injury site in two cases, microcoils in two patients, microcoils plus a single barrel extra-intracranial high-flow bypass in one case, stent grafting in one case, and no intervention in two cases. The risk of ICA injury diminishes with better preoperative preparation, intraoperative navigation, and ultrasound dopplerography. Reconstructive surgery for closing the defect and restoring the blood flow to the artery should be assessed depending on the site of the injury and the anatomical features of the ICA.

Open-Source Federated Learning Frameworks for IoT: A Comparative Review and Analysis.

The rapid development of Internet of Things (IoT) systems has led to the problem of managing and analyzing the large volumes of data that they generate. Traditional approaches that involve collection of data from IoT devices into one centralized repository for further analysis are not always applicable due to the large amount of collected data, the use of communication channels with limited bandwidth, security and privacy requirements, etc. Federated learning (FL) is an emerging approach that allows one to analyze data directly on data sources and to federate the results of each analysis to yield a result as traditional centralized data processing. FL is being actively developed, and currently, there are several open-source frameworks that implement it. This article presents a comparative review and analysis of the existing open-source FL frameworks, including their applicability in IoT systems. The authors evaluated the following features of the frameworks: ease of use and deployment, development, analysis capabilities, accuracy, and performance. Three different data sets were used in the experiments-two signal data sets of different volumes and one image data set. To model low-power IoT devices, computing nodes with small resources were defined in the testbed. The research results revealed FL frameworks that could be applied in the IoT systems now, but with certain restrictions on their use.

Endoscopic Transsphenoidal Approach in Treatment of Germinomas of the Chiasmosellar Region.

INTRODUCTION: Germinogenic central nervous system (CNS) tumors represent a heterogeneous group of tumors, constituting approximately 0.4% of all primary brain tumors. Removal of the tumor has no prognostic value. In "pure" primary germinomas of the CNS, the alpha-fetoprotein and human chorionic gonadotropin levels are within normal limits, and no specific biochemical tumor markers currently exist for this tumor type, making histological verification crucial for the choice of treatment tactics. When the tumor is located in the chiasmosellar region, one of the possible verification methods is endoscopic endonasal transsphenoidal biopsy. OBJECTIVE: The main objective of the study is to demonstrate the feasibility and safety of endoscopic transsphenoidal approach for histological verification of primary germinomas of the CNS with chiasmosellar localization. MATERIALS AND METHODS: The current study includes 13 patients with "pure" germinomas of the chiasmosellar region who underwent endoscopic endonasal surgical interventions with subsequent treatment according to the "Germinoma 2008" protocol. RESULTS: The extent of surgical intervention ranged from biopsy (4) to partial (5) and total (4) removal of the tumor. In all cases, histological verification of the diagnosis was achieved and none of the patients presented with cerebrospinal fluid leaks and/or meningitis in the postoperative period, allowing to evaluate endoscopic intervention in our patient series as safe and effective. Two out of 13 patients were lost to follow-up. CONCLUSION: The endoscopic endonasal approach for histological verification and removal of chiasmosellar region germinomas is safe, and in some cases, less traumatic for the patient than transcranial and transventricular approaches.

Amygdalohippocampectomy via the Lateral Extended Transsphenoidal Endoscopic Approach Through the Pterygopalatine Fossa: An Anatomic Study.

BACKGROUND: The lateral extended transsphenoidal endoscopic approach (LETEA) is used to remove tumors located lateral to the cavernous segment of the internal carotid artery under direct visual control and provides access to Meckel cave, pterygopalatine fossa, medial part of the middle cranial fossa, and orbit. We describe an extended transsphenoidal approach to the amygdalohippocampectomy through the pterygopalatine fossa. METHODS: The LETEA to the middle cranial fossa through the pterygopalatine fossa was studied on 3 injected human cadavers at the Burdenko Neurosurgery Institute in Moscow, Russia. RESULTS: LETEA and trepanation of the greater wing of the sphenoid bone allow access to the medial part of the middle cranial fossa. Medial segments of the temporal lobe (hippocampus and amygdala) and the temporal pole were removed under guidance of the 45° angled endoscope. CONCLUSIONS: LETEA through the pterygopalatine fossa is minimally invasive and provides direct access to the temporal pole and medial part of the temporal lobe. This approach may reduce risk of neurologic deficit and help to avoid cosmetic defects in the frontotemporal region associated with injury to temporal muscle and facial nerve injury as can occur during transcranial approaches. Disadvantages that limit application of LETEA include risk of cerebrospinal fluid leak and skills needed for manipulation in a narrow and deep surgical field with angled 30° and 45° endoscopes.

Endoscopic Transnasal Transclival Resection of Endodermal Cyst on Ventral Surface of Brainstem.

BACKGROUND AND IMPORTANCE: Endodermal cysts are a rare pathology of the central nervous system located mostly in the upper thoracic or cervical regions. Seldomly, the cysts are found intracranially, most often in the subtentorial area (on the ventral surface of the brainstem, pontocerebellar angle, and fourth ventricle). Traditional approaches to the ventral surface of the brainstem are complicated and traumatic, and they do not provide a good view of the tumor's central and contralateral parts. In this case report, we present an alternative approach for resection of the endodermal cyst on the ventral surface of the brainstem. CLINICAL PRESENTATION: Our patient, 27 years old, was observed for 6 years with a preliminary diagnosis of pilocytic astrocytoma. Previously, the patient had an Ommaya system implanted into the cyst and underwent stereotactic radiotherapy (54 Gy). The tumor was resected through an extended transsphenoidal transclival endonasal endoscopic approach. Histologic examination confirmed the diagnosis of endodermal cyst. Significant regression of the symptoms was noted. Complications were not seen. CONCLUSION: The main advantage of the transclival transnasal approach is the direct access to the clivus and ventral surface of the brainstem without traction of the cerebral structures. If the transsphenoidal transclival approach is used, the cranial nerves are out of the approach area that minimizes the risk to damage it. An extended transsphenoidal transclival endonasal endoscopic approach is an alternative to traditional microsurgical approaches to pathologic processes on the ventral surface of the brainstem (cavernomas, endodermal cysts), located centrally.

Endoscopic Endonasal Surgery of Epidermoid Cysts of the Chiasmatic Region.

BACKGROUND: Despite the rarity of epidermoid cysts in the chiasmatic region, their surgical treatment is particularly complicated because of the tendency toward massive dissemination of the epidermoid masses along cerebrospinal fluid pathways and significant deviation of the tumor from the midline. OBJECTIVE: The purpose of the present work is evaluation of the role of extended transsphenoidal endoscopic endonasal approaches in the surgery of epidermoid cysts. METHODS: The study included 6 patients with epidermoid cysts in the chiasmatic region who were operated on at the Burdenko Neurosurgery Institute in the last 5 years using an anterior extended transsphenoidal endoscopic endonasal approach. RESULTS: The epidermoid masses were totally removed in 5 patients, but in no patient was it possible to completely remove the epidermoid cyst capsule. Visual deterioration was not noted in any patient, nor did new focal neurologic symptoms appear. One of the patients developed hypopituitary disorders in the postoperative period. No recurrence of the epidermoid cysts was observed during the follow-up period. CONCLUSIONS: Removal of epidermoid cysts in the chiasmatic region using an anterior extended transsphenoidal endoscopic approach may be an alternative to transcranial microsurgery operations. This technique is widely accepted as an approach to this area.

Extended Transsphenoidal Endoscopic Endonasal Surgery of Suprasellar Craniopharyngiomas.

OBJECTIVE: The endoscopic extended transsphenoidal approach for suprasellar craniopharyngiomas may be a really alternative to the transcranial approach in many cases. The authors present their experience with this technique in 136 patients with craniopharyngiomas. METHODS: From the past 7 years 204 patients with different purely supradiaphragmatic tumors underwent removal by extended endoscopic transsphenoidal transtuberculum transplanum approach. Most of the patients (136) had craniopharyngiomas (suprasellar, intra-extraventricular). The patients were analyzed according to age, sex, tumor size, growth and tumor structure, and clinical symptoms. Twenty-five patients had undergone a previous surgery. The mean follow-up was 42 months (range, 4-120 months). The operation is always performed with the bilateral endoscopic endonasal anterior extended transsphenoidal approach. RESULTS: A gross-total removal was completed in 72%. Improvement of vision or absence of visual deterioration after operation was observed in 89% of patients; 11% had worsening vision after surgery. Endocrine dysfunction did not improve after surgery, new hypotalamopituitary dysfunction (anterior pituitary dysfunction or diabetes insipidus) or worsening of it was observed in 42.6%. Other main complications included transient new mental disorder in 11%, temporary neurological postoperative deficits in 3.7%, bacterial meningitis in 16%, cerebrospinal fluid leaks in 8.8%. The recurrence rate was 20% and the lethality was 5.8%. CONCLUSIONS: Resection of suprasellar craniopharyngiomas using the extended endoscopic approach is a more effective and less traumatic technology, able to provide resection of the tumor along with high quality of life after surgery, and relatively rare postoperative complications and mortality.