Objective: Saccular aneurysms of the basilar artery (BA) trunk are a significant challenge in neurosurgery due to their rarity and the complexity of surgical approaches. This study examines the efficacy and outcomes of microsurgical treatment for these aneurysms, highlighting the advantages over endovascular methods in terms of occlusion rates and complication management. Methods: A retrospective review of 23 patients with BA trunk aneurysms treated microsurgically at the Moscow Regional Clinical Research Institute from June 2019 to April 2024 was conducted. Patient demographics, aneurysm characteristics, surgical techniques, and postoperative outcomes were analyzed. Results: The study group included 16 women and 7 men, with an average age of 51.2 years. Notably, 19 of 23 patients (82.6%) presented with subarachnoid hemorrhage (SAH), while 4 had unruptured aneurysms (2 asymptomatic, 2 with mass effect). Aneurysms were predominantly located at the origin of the superior cerebellar artery (SCA). Surgical approaches varied based on aneurysm location, with most utilizing the orbito-pterional approach. Complete occlusion was achieved in all cases and was maintained over the follow-up period without signs of recanalization. Complications included transient oculomotor nerve dysfunction in 5 patients, with a substantial recovery rate. Favorable outcomes (mRS 0–2) were achieved in 87% of patients, including most SAH cases, highlighting the safety and effectiveness of treatment. Conclusions Microsurgical treatment of BA trunk aneurysms provides a reliable occlusion with a low rate of complications and excellent clinical outcomes. This series supports microsurgery as a preferred option for managing these challenging aneurysms, particularly when located at the SCA origin.

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.