Tumors of the lateral and third ventricles of the brain are uncommon in the general population. Taking into account possible disability, expected duration and quality of life of the patient in the postoperative period, radical removal of these tumors, especially invasive ones, are debatable. Purpose: to determine the possibilities of endoscopic transventricular surgery for tumors of the lateral and third ventricles of the brain. Materials and methods. Between 2015 and 2021, 61 patients with lateral and third ventricle tumors were treated, 9 of which were primary and 52 were invasive.All patients had a preoperative Karnofsky Performance scale score ≥70 points. Preoperative neurological status: non-focal neurological symptoms were observed in all patients, central significant hemiparesis (up to 2 points) - in 5, cognitive-mnestic disorders - in 31, opto-chiasmatic syndrome - in 2. Obstructive hydrocephalus was diagnosed in all patients. All patients underwent full-endoscopic removal by frontal transcortical transventricular approach. Results. Total tumor resection (within healthy tissues) was performed in 34 patients, subtotal (up to 90%) – in 17, partial – in 10 patients. The postoperative condition according to Karnofsky Performance scale in all patients was ≥70 points. Hemiplegia was registered in 8 (13.1%) patients (sustained deficiency, hemiparesis (up to 3 points) - in 2 (1.22%) patients), hemianopsia - in 4 (6.5%) patients, short-term memory impairment - in 9 ( 14.75%), regression was observed 2–4 weeks after surgery. Thirty-seven (60.7%) patients died. The remaining patients (39.3%) are under observation. Median survival was 33 weeks (95% confidence interval (CI) 28–40 weeks). Postoperative survival in patients with glioblastoma was 15 weeks, median survival was 9.5 weeks (95% CI, 4–15 weeks). Of the patients with anaplastic astrocytoma, 13 (92.9%) patients died within 38 weeks after surgery, the median survival was 18 weeks (95% CI, 14.5–29.0 weeks), 1 (7.1%) patient was under observation. Patients with anaplastic oligodendroglioma had a median survival of 34.5 weeks (95% CI - 28-40 weeks), 15 (65.2%) patients died within 40 weeks, 8 (34.8%) patients are under observation. The difference between groups in survival was statistically significant (p<0.0001). Median survival in women was 34.5 weeks (95% CI, 29–40 weeks), in men, 28 weeks (95% CI, 18–39 weeks). There were 12 (42.9%) women and 12 (36.4%) men who survived for more than 60 weeks. No statistically significant difference was found between male and female survival rates (p=0.309). Conclusions. The ability of achieving the optimal resection volume of primary and invasive tumors of the third and lateral ventricles allows recommending the anterior endoscopic transcortical transventricular approach as an effective method of surgical treatment of these tumors. Radical endoscopic resection, as the first stage of combined treatment of patients with malignant tumors of the third and lateral ventricles, increases the patients’ life expectancy with a minimal risk of postoperative neurological complications, comparable to the life expectancy of patients with malignant tumors of supratentorial localization. To eliminate obstructive hydrocephalus and prevent the obstruction of CSF circulation in case of postoperative edema or continued growth in invasive tumors of the lateral and third ventricles, it is advisable to perform triventriculocisternostomy.

Objective: to analyze the results of using various methods of plastic closure of bone defects of the anterior cranial fossa (ACF) floor when removing craniofacial tumors of the ACF floor depending on the size of the defect. Materials and methods. A retrospective analysis of treatment outcomes of 122 patients with craniofacial tumors of the ACF floor was carried out. According to the nature of the lesions malignant craniofacial tumors were detected in 98 (80.3%) patients, and benign ones in 24 (19.7%) patients. The following neurosurgical approaches to craniofacial tumors of the ACF floor were used: bifrontal - in 58 (47.5%) patients, subcranial - in 49 (40.2%), transbasal Derome - in 8 (6.5%), frontotemporal - in 4 (3.25%), expanded endoscopic - in 3 (2.45%). In 52 (42.6%) cases, endoscopic endonasal assistance was used, most often in the case of plasty of large ACF floor defects to revise the surgical defect, assess the sufficiency of plasty and tamponade of the nasal cavity with balloon catheters. Results. Patients were divided into groups depending on the bone defect of the ACF floor: median - in 27 (22.1%), middle-expanded - in 71 (58.2%), middle-lateral - in 24 (19.7%). The following types of plasty of the bone defect of the ACF floor were used: pedicle flap - 83 (68.0%) cases, free flap - 22 (18.1%), pedicled periosteal flap with reinforcement - 17 (13.9%). Postoperative complications occurred in 17 (13.9%) patients: nasal liquorrhea in 10 (8.2%) patients (of which 6 underwent reoperation to eliminate it), in 7 patients it was complicated by meningoencephalitis, in other 7 (5.7 %) - meningoencephalitis without signs of nasal cerebrospinal fluid. Postoperative mortality was 0.71% (1 patient). The frequency of nasal cerebrospinal fluid in the group of plasty using a free flap was 13.6% (3 cases), meningoencephalitis - 4.5% (1 observation), in the group of plasty using pedicle flap - 4.8% (4 cases) and 6.0% (5 observations), in the group of plasty using a pedicle flap with reinforcement - 17.6% (3 cases) and 11.7% (2 observations). In 33 (27.1%) cases the use of the author's method of bone defect plasty of the ACF floor with duplication of complications were not registered. Conclusions. Significant size and spread of bone defects of the ACF floor increase the risk of postoperative complications. The use of free flaps for plasty of the bone defect of the ACF floor is ineffective and is associated with a high risk of complications. The proposed method of plasty of the posterior parts of the ACF floor by duplication of the periosteal flap promotes the sealing of the posterior parts, where suturing causes certain difficulties. Reinforcement of plasty from the side of the nasal cavity due to endoscopic technique using tamponade or balloon catheters reduces the incidence of postoperative complications.