[A technique of manufacturing anatomical preparations of the human brain based on injecting vessels with colored silicone (a technical note)]. / Sposob izgotovleniia anatomicheskikh preparatov golovnogo mozga cheloveka s in''ektsiei sosudov tsvetnym silikonom (tekhnicheskoe opisanie).

OBJECTIVE: The objective was to produce anatomical preparations by injecting vessels with colored silicone to study the brain and skull base anatomy. MATERIAL AND METHODS: Fresh, undissected, and unfixed cadavers were used. The internal carotid arteries and internal jugular veins were identified on both sides of the neck. The vessels were washed with running water. Then, a complex solution consisting of white silicone rubber, silicone oil (solvent), and a coloring pigment (red and blue pigments) at a ratio of 1:(0.9-1.1):(0.04-0.06), respectively, was prepared. About 30-60 s before injecting the complex solution into the vessels, a catalyst-hardener was added to the solution at a ratio of 1:(0.05-0.07). The complex solution was first introduced into the internal carotid artery until the solution came out from the contralateral internal carotid artery; then, the solution was injected into the internal jugular vein until the solution emerged from the contralateral internal jugular vein. RESULTS: The technique enables quick and high-quality visualization of both large and very small vessels of the brain and skull base. CONCLUSION: The proposed simple and inexpensive technique of manufacturing anatomical preparations improves the quality of training and mastering of microsurgical skills in residents and practicing neurosurgeons.

[Extended endoscopic endonasal posterior (transclival) approach to tumors of the clival region and ventral posterior cranial fossa. Part 2. Topographic and anatomical aspects and surgical technique]. / Éndoskopicheskii éndonazal'nyi zadnii rasshirennyi (transklival'nyi) dostup k opukholiam oblasti skata cherepa i ventral'nykh otdelov zadnei cherepnoi iamki. Chast' 2. Topografo-anatomicheskie aspekty i operativnaia tekhnika.

PURPOSE: to present the main topographic and anatomical features of the clivus and adjacent structures for improving and optimizing the extended endoscopic transnasal posterior (transclival) approach in removal of clival and ventral posterior cranial fossa lesions. MATERIAL AND METHODS: We performed a topographic and anatomical study of 25 cadaver heads, the vascular bed of which was filled with colored silicone using the original technique for visualizing the bed features and individual variability. RESULTS: We present the main anatomical landmarks necessary for performing the extended endoscopic endonasal posterior approach. Superior, medial, and inferior transclival approaches provide access to the anterior surface of the upper, middle, and lower neurovascular complexes of the posterior cranial fossa. CONCLUSION: The endoscopic transclival approach can be used to reach ventral posterior cranial fossa lesions. The endoscopic transnasal transclival approach is an alternative to transcranial approaches to clival lesions.

[Extended endoscopic endonasal posterior (transclival) approach to tumors of the clival region and ventral posterior cranial fossa. Part 1. Topographic and anatomical features of the clivus and adjacent structures]. / Éndoskopicheskii éndonazal'nyi zadnii rasshirennyi (transklival'nyi) dostup k opukholiam oblasti skata i ventral'nykh otdelov zadnei cherepnoi iamki. Chast' 1. Topografo-anatomicheskie osobennosti skata i pogranichnykh s nim obrazovanii.

OBJECTIVE: to describe the main topographic and anatomical features of the clival region and its adjacent structures for improvement and optimization of the extended endoscopic endonasal posterior (transclival) approach for resection of tumors of the clival region and ventral posterior cranial fossa. MATERIAL AND METHODS: We performed a craniometric study of 125 human skulls and a topographic anatomical study of heads of 25 cadavers, the arterial and venous bed of which was stained with colored silicone (the staining technique was developed by the authors) to visualize bed features and individual variability. Currently, we have clinical material from more than 120 surgical patients with various skull base tumors of the clival region and ventral posterior cranial fossa (chordomas, pituitary adenomas, meningiomas, cholesteatomas, etc.) who were operated on using the endoscopic transclival approach. RESULTS: We present the main anatomical landmarks and parameters of some anatomical structures that are required for performing the endoscopic endonasal posterior approach. The anatomical landmarks, such as the intradural openings of the abducens and glossopharyngeal nerves, may be used to arbitrarily divide the clival region into the superior, middle, and inferior thirds. The anatomical landmarks important for the surgeon, which are detected during a topographic anatomical study of the skull base, facilitate identification of the boundaries between the different clival portions and the C1 segments of the internal carotid arteries. The superior, middle, and inferior transclival approaches provide an access to the ventral surface of the upper, middle, and lower neurovascular complexes in the posterior cranial fossa. CONCLUSION: The endoscopic transclival approach may be used to access midline tumors of the posterior cranial fossa. The approach is an alternative to transcranial approaches in surgical treatment of clival region lesions. This approach provides results comparable (and sometimes better) to those of the transcranial and transfacial approaches.

[Endoscopic transsphenoidal resection of pituitary adenomas invading the cavernous sinus]. / Endoskopicheskoe transsfenoidal'noe udalenie adenom gipofiza, vrastayushchikh v kavernoznyi sinus.

INTRODUCTION: Pituitary adenomas are benign growths that invade the cavernous sinus (CS) in 10-15% of cases. There are different types of microsurgical and endoscopic approaches enabling resection of tumors from the CS cavity that is a relatively small and hard to reach anatomical structure comprising eloquent neurovascular structures. MATERIAL AND METHODS: A study group included 97 patients with pituitary adenomas (PAs) invading the CS. PAs were resected using an endoscopic technique: adenomas were resected from the CS cavity through a standard endoscopic endonasal transsphenoidal approach in 62 cases; a lateral extended transsphenoidal endoscopic approach was used in 35 cases. A control group included patients with PAs spreading into the laterosellar region who were operated on using microsurgical extra-intradural (n=14) and transsphenoidal (n=149) approaches. In the study group, the degree of PA invasion into the CS cavity was determined using the Knosp scale. RESULTS: In the study group, total tumor resection was achieved in 49 (50.5%) cases, subtotal resection in 39 (40.2%) cases, and partial resection in 9 (9.3%) patients. In the case of visual disorders (n=70), vision improvement was achieved in 41.4% of cases. Vision deterioration was detected in 11.4% of cases; no vision changes were in 47.1% of cases. Patients (27.8%) who had not had visual impairments before surgery had no negative changes in vision in the postoperative period. The development/augmentation of oculomotor disorders in the study group occurred in 14 (14.4%) cases. In the study group, hormonal remission of the disease in patients with hormone-active PAs was in 26.7% of cases (n=12). There were no cases of nasal liquorrhea, meningitis, and death in the study group. CONCLUSION: Endoscopic endonasal transsphenoidal resection of PAs invading the CS is a more efficient and safer surgical technique compared to microsurgical techniques (transsphenoidal and extra-intradural approach). The lateral extended transsphenoidal endoscopic approach enables resection of PAs with massive invasion into the CS (Grade III and Grade IV, Knosp scale) and has less postoperative complications compared to the extra-intradural approach (p<0.05).

[Surgical anatomy of the insular cortex].

OBJECTIVE: The objective of the study was to investigate the surgical anatomy of the insular cortex, morphology and vascularization of the insula and adjacent opercula in terms of transsylvian and transcortical approaches, and identification of the permissible anatomical boundaries for resection of glial tumors of the insula. MATERIAL AND METHODS: The study was conducted on 18 anatomical specimens fixed in an alcohol-glycerol solution. Perfusion of the internal carotid artery with red latex was used to study the arterial system. Dissection of the arteries and Sylvian fissure, investigation of the morphological features of the opercula as well as simulation of the transsylvian and transcortical approaches to the insula were performed using a surgical microscope, in a certain sequence. RESULTS: In the trassylvian approach, the anteroinferior part of the insula (including the limen insulae) is the most technically easy-to-reach area, whereas the superior parts of the insula are the most difficult-to-reach areas. With the tumor localized in the superior insula, the transcortical approach may be recommended that, unlike the transsylvian approach, does not require a significant retraction of the brain matter and provides a larger surgical corridor. The transcortical approach, regardless the insular region, provides a better surgical view and workspace compared to the transsylvian approach. However, the previous approach is characterized by less access to the important anatomical landmarks such as the peri-insular sulci, limen insulae, and lateral lenticulostriate arteries. Furthermore, the approach requires dissection of the brain matter of the frontal and temporal lobes. CONCLUSION: Detailed knowledge of the surgical anatomy of the insular region provides correct intraoperative identification of a number of the major anatomical landmarks (limen insulae, peri-insular sulci, most distal lenticulostriate artery) and facilitates choosing the proper surgical approach.