[Autologous fibrin glue for endoscopic skull base repair in patients with cerebrospinal fluid leakage]. / Primenenie autologichnogo fibrinovogo kleya v endoskopicheskoi plastike defektov osnovaniya cherepa pri nazal'nykh likvoreyakh.

The main stages of endoscopic skull base repair in patients with cerebrospinal fluid (CSF) leakage are identification of bone boundaries of the fistula and its closure by auto- and allografts. Fibrin glue can be used to fix plastic materials and additionally seal skull base defect. OBJECTIVE: To analyze efficacy and safety of Vivostat autologous fibrin glue for endoscopic skull base repair in patients with nasal CSF leakage and to compare postoperative outcomes after defect closure by Vivostat fibrin glue and allogeneic fibrin glue. MATERIAL AND METHODS: A retro- and prospective analysis included 56 patients with nasal CSF leakage who were treated at the Burdenko Neurosurgery Center between January 2021 and June 2022. Patients were divided into 2 groups: Vivostat fibrin glue (n=27, 48.2%) and allogeneic fibrin glue (n=29, 51.8%). Demographic and clinical perioperative data were analyzed. RESULTS: No early postoperative recurrence of CSF leakage was registered in both groups, whereas meningitis occurred in 2 cases in each group. Recurrent CSF leakage in delayed postoperative period occurred in 1 patient (3.4%) of the control group (p>0.05). Incidence of perioperative complications, subfebrile temperature in early postoperative period, surgery time and hospital-stay were similar. CONCLUSION: Vivostat autologous fibrin glue is a safe and effective method for fixing the grafts in endoscopic skull base repair. The advantages of this approach are easy application, elimination of the risk of allergic, immunological and infectious complications, as well as acceleration of tissue regeneration.

[Chordoid gliomas of the third ventricle]. / Opyt lecheniya khordoidnykh gliom III zheludochka.

BACKGROUND: Chordoid glioma is a rare slow-growing tumor of the central nervous system. Available world experience includes no more than 200 cases (lesion of the third ventricle in absolute majority of cases). Recognition and treatment of chordoid glioma are currently difficult problems due to small incidence of this disease. OBJECTIVE: To describe clinical manifestations and surgical treatment of chordoid glioma of the third ventricle considering literature data and own experience. MATERIAL AND METHODS: There were 12 patients (6 men and 6 women) with chordoid glioma between 2004 and 2023 (10 patients with lesion of the third ventricle, 1 - lateral ventricle, 1 - pineal region). Only patients with tumors of the third ventricle were analyzed. RESULTS: Total and subtotal resection was performed in 1 and 3 cases, respectively. Five patients underwent partial resection, 1 patient underwent biopsy. The follow-up data were available in 7 out of 10 patients (mean 25 months). Radiotherapy was performed in 4 patients (continued tumor growth in 2 cases). One patient died. CONCLUSION: Chordoid glioma is a benign tumor predominantly localized in the third ventricle. Preoperative MRI and CT in some cases make it possible to suspect chordoid glioma and differentiate this tumor from craniopharyngioma, meningioma and pituitary adenoma by such signs as isointense signal in T1WI, hyper- or isointense signal in T2WI, homogeneous contrast enhancement and edema of basal ganglia in T2 FLAIR images. The only effective treatment for chordoid glioma is surgery. Total resection is often impossible or extremely dangerous due to location of tumor, large size and invasion of the third ventricle. Postoperative mental disorders and diabetes insipidus, including severe hypernatremia, are common that requires mandatory monitoring of water and electrolyte balance.

[Differential diagnosis of pneumonia as a complication of nasal liquorrhea in the context of the COVID-19 pandemic: Case report].

Nasal liquorrhea the outflow of cerebrospinal fluid from the cerebrospinal fluid spaces of the cranial cavity into the nasal cavity or paranasal sinuses due to the presence of a congenital or acquired defect in the bones of the skull base and meninges of various etiologies. Nasal liquorrhea leads to potentially fatal complications: meningitis, meningoencephalitis, pneumocephalus, brain abscess. Also, with nasal liquorrhea, less dangerous complications may occur: aspiration bronchopneumonia and gastritis. The article presents a case of aspiration pneumonia in two patients with nasal liquorrhea treated at the Burdenko National Medical Research Center for Neurosurgery during the COVID-19 pandemic. Both patients noted the profuse nature of the nasal liquorrhea, complained of coughing in a horizontal position. In both cases, no RNA virus (SARS-CoV-2) was detected during the polymerase chain reaction. Antibodies (IgG, M) to coronavirus were not detected. Computed tomography of the chest organs in both cases revealed areas of frosted glass darkening. Since no data was obtained for coronavirus infection (negative tests for coronavirus, lack of antibodies), changes in the lungs were interpreted as a consequence of constant aspiration of CSF. The patients were admitted to a separate ward. Both patients underwent endoscopic endonasal plasty of the skull base defect. The postoperative period in both cases was uneventful. In both cases, the patients underwent computer tomography scan of the chest organs one month later. On the photographs, the signs of pneumonia completely regressed.

[Nosocomial meningitis in endoscopic transsphenoidal surgery]. / Nozokomial'nye meningity v endoskopicheskoi transsfenoidal'noi khirurgii.

One of the main problems of transsphenoidal surgery is the risk of infectious complications. Nosocomial meningitis (NCM) can lead to increased length of hospital stay and financial costs, poor treatment outcomes and even mortality. This complication is an indicator of the quality of medical care for patients with neurosurgical diseases. The purpose of the review was to study the main risk factors of NCM, modern schemes for antibiotic prophylaxis and treatment of this complication after endoscopic transsphenoidal surgery. The main risk factors of meningitis are intra- and postoperative CSF leakage, overweight, diabetes mellitus, previous transsphenoidal surgeries and radiotherapy. To date, there are no generally accepted periods for antibiotic prophylaxis in nasal CSF leakage, installed external ventricular / lumbar drains or tampons in nasal cavity. Antibiotic prophylaxis should not exceed 3 postoperative days due to the risk of cultivating the drug-resistant organisms. If NCM is detected, treatment should be initiated immediately with a broad spectrum of antibiotics.

[Application of autologous fibrin glue for skull base defect closure in transsphenoidal surgery. Case report and literature review]. / Primenenie autologichnogo fibrinovogo kleya dlya plastiki defekta osnovaniya cherepa v transsfenoidal'noi khirurgii. Opisanie klinicheskogo sluchaya i obzor literatury.

Nasal CSF leakage is the most common complication after transsphenoidal surgery, especially in case of extended transsphenoidal access. It is one of the main and obvious risk factors of meningitis. Introduction of effective reconstructive techniques made it possible to reduce the incidence of postoperative CSF leakage. Fibrin glue is one of the main components in transsphenoidal surgery for skull base defect closure. The use of autologous fibrin glue excludes immune response due to its biocompatibility. Modern technologies of preparation of autologous fibrin glue make it possible to obtain a large volume of glue that ensures complete sealing of skull base defect. At the same time, autologous glue contains factors promoting rapid tissue regeneration. It is of great importance for engraftment of autologous transplants in the area of skull base defect.

[Transcranial microsurgical decompression of the optic canal in surgical treatment of meningiomas of the sellar region]. / Transkranial'naya mikrokhirurgicheskaya dekompressiya kanala zritel'nogo nerva v khirurgii meningiom khiazmal'no-sellyarnoi oblasti.

RATIONALE: When removing the meningiomas of the sellar region, there is always a risk of visual impairment for various reasons, in particular, as a result of traction damage to the optic nerve. Decompression of the optic canal increases nerve mobility during tumor manipulation. In cases of meningioma growing into the canal, its decompression often seems necessary. AIM: Evaluation of the effectiveness and risks of performing decompression of the optic canal. MATERIALS AND METHODS: The study included patients with meningiomas of the parasellar location, who underwent surgical treatment at the Burdenko Neurosurgical Center for the period from 2001 to 2017. They were divided into two groups - main and control. The main group consisted of 129 patients who underwent decompression of the optic nerve canals when the tumor was removed. The tumor matrix in this group was most often located in the region of the tuberum sellae, supradiaphragmally, in the region of the anterior clinoid process and the optic canal. In 31 cases, decompression was bilateral - during one operation and using one access in 27 patients; in 4 cases, the decompression of the second canal was delayed for 1.5-3 months after the first operation. 160 decompressions were performed by the intradural and 7 - by extradural methods. During intradural decompression, the roof of the optic canal was resected, and during extradural decompression, the lateral wall of the canal was trephined. The control group consisted of 308 patients who did not undergo canal decompression when the tumor was removed. It included meningiomas with a predominant location of the matrix in the area of the tuberclum and diaphragm of the sella. Tumors in both groups were removed according to the same principles (matrix coagulation, mainly the gradual removal of the tumor, the use of ultrasonic aspirator, a situational decision on the radicality of the operation, etc.). The main difference between operations in these two groups was only canal related algorithms (with or without its trepanation), as well as the probable prevalence of significant lateral tumor growth in cases with canal trepanation. Visual functions in the «primary¼ group were evaluated before and after operations with trepanation of the canal depending on various factors - the initial state of vision and the radicality of the tumor excision, including removal from the canal. The differences in the postoperative dynamics of vision in the main and control groups were studied. The primary data processing was carried out using the program MSExcel. Secondary statistical processing was carried out using the program Statistica. To assess the statistical significance of differences in the results obtained in the compared patient groups, the Chi-square test was used, and in the case of small groups - the exact Fisher test was applied. RESULTS: In the main group postoperative vision improvement of varying degrees on the side of trepanation was registered in 36.9% (59 out of 160) cases, no vision changes were found in 36.9% (59 out of 160), and in 26,2% (42 out of 160) the eyesight deteriorated. If preserving vision is attributed to a satisfactory result, then in general the results of these operations should be considered good. A comparative study of the results of removal of meningiomas with trepanation of the canals (main group) or without it (control group) was carried out among patients with the most critical vision situation (visual acuity 0.1 and below, up to only light perception). These groups are comparable in the number of observations - 62 and 73 respectively. The predominance of cases with improved vision in the main group compared with the control group (50.0% versus 38.36%) and a lower incidence of vision impairment (22.58% versus 34.25%) were found. However, the revealed differences are statistically unreliable and make it possible for us to talk only about the trend. The complications associated with trepanation of the canal include mechanical damage to the nerve by the drill. In our series of observations, there was only 1 case of abrasion of the nerve surface with the burr, which did not lead to a significant visual impairment. With the intradural method of trepanation in the area of the medial wall of the canal, the sphenoid sinus may open (in our series, in 34 cases out of 160 trepanations). Immediately closure of these defects was performed by various auto- and allomaterials in various combinations (pericranium, fascia, muscle fragment, hemostatic materials, and fibrin-thrombin glue). A true complication - CSF rhinorrhea liquorrhea developed in only one case, which required transnasal plastic surgery of the CSF fistula using a mucoperiostal flap. CONCLUSIONS: 1. Trepanation of the optic canal in cases of meningiomas of parasellar localization is a relatively safe procedure in the hands of a trained neurosurgeon and does not worsen the results of operations compared with the excision of the same tumors without trepanation of the canal. 2. The literature data and the results of our study make it possible to consider the decompression of the optic canal as an optional, but in many cases, useful option that facilitates the transcranial removal of some meningiomas of the sellar region.

[Oculomotor nerve neurinomas. Case reports and a literature review]. / Nevrinomy glazodvigatel'nogo nerva. Opisanie klinicheskikh sluchaev i obzor literatury.

Oculomotor nerve neurinoma not associated with neurofibromatosis type II is an extremely rare pathology. According to the topography, cisternal, cisternocavernous, cavernous, orbitocavernous, and orbital tumor groups are distinguished. The clinical picture of the disease is characterized mainly by either oculomotor disorders or pyramidal symptoms, depending on the tumor localization. Neurinomas of the oculomotor nerve rarely occur without oculomotor disorders. However, in some patients with these tumors, the third nerve function remains intact. In this paper, we present clinical cases of two patients with oculomotor nerve neurinomas and analyze the relevant literature.

[Transsphenoid extirpation of pituitary adenomas in patients with McCune-Albright syndrome (two cases from practice and literature review)]. / Transsfenoidal'noe udalenie adenom gipofiza u patsientov s sindromom MakK'iuna-Olbraita (dva sluchaia iz praktiki i obzor literatury).

INTRODUCTION: McCune-Albright Syndrome is a rare genetic disease characterized by the formation of fibrous osteodysplasia foci of various localization, including the bones of skull base. Having a gross lesion of the main bone body and the simultaneous formation of the pituitary adenoma, its transnasal removal becomes very difficult. MATERIAL AND METHODS: Two clinical observations are presented where at patients with the classic manifestation of McCune-Albright syndrome we were able to successfully remove somatotropinomas with endoextrasellar growth. In both cases the presence of visual disorder was the indication for surgery. RESULTS: Despite pronounced deviations in the anatomy of the skull base bones in both cases we managed to access the Turkish saddle. Removal of the pituitary tumor did not differ from standard surgery. Improved vision after surgery was observed in two patients. Tumors were removed subtotally and clinical and biochemical remission of acromegaly was not achieved. In both cases, the tumors had morphological signs of atypia. Patients continued to receive therapy with somatostatin analogues and radiation. CONCLUSION: The possibility of performing transnasal surgery in this category of patients using specific instruments and intraoperative navigation is shown.

[Monitoring of adverse event triggers as a tool for managing the medical care quality at a neurosurgical clinic. Invitation to the discussion]. / Monitoring triggerov neblagopriiatnykh sobytii kak instrument upravleniia kachestvom meditsinskoi pomoshchi v neirokhirurgicheskoi klinike. Priglashenie k diskussii.

Management of the healthcare quality and safety is one of the priorities of state policy for protecting health of Russian citizens. We describe modern technologies for managing the quality of medical care and patient safety based on a systematic approach. Potential applications of these technologies in neurosurgical practice are defined. Quantitative, qualitative, and basic indicators are proposed for evaluation of outcomes (results) as part of implementation of an integrated quality management system in neurosurgical practice.

[Lateral extended transsphenoidal endoscopic approach through the pterygopalatine fossa in surgery for meningoencephalocele of the lateral sphenoid recess]. / Lateral'nyi rasshirennyi transsfenoidal'nyi éndoskopicheskii dostup cherez krylovidno-nebnuiu iamku v khirurgii meningoéntsefalotsele bokovogo karmana klinovidnoi kosti.

Meningoencephalocele is a hernial protrusion of the medulla and meninges through a defect in the skull bones. Due to poor accessibility of meningoencephalocele located in the lateral sphenoid recess region, modern surgical treatment of this pathology prefers to use endoscopic transsphenoidal approaches. MATERIAL AND METHODS: The study included 4 patients with meningoencephalocele of the lateral recess of the sphenoid sinus (1 male and 3 females; mean age, 46.8 years). All patients underwent resection of meningoencephalocele and repair of a skull base defect using the lateral extended transsphenoidal endoscopic approach through the pterygopalatine fossa (transpterygoid approach). RESULTS: In all patients, meningoencephalocele was resected to the bone defect level. There was no postoperative liquorrhea. Complications included bacterial meningitis (1 case), asymptomatic imbibition of the temporal lobe pole (1 case), and temporary numbness in the V2 innervation area of the trigeminal nerve (1 case). CONCLUSION: The paper describes and demonstrates advantages of the lateral extended transsphenoidal endoscopic approach through the pterygopalatine fossa (transpterygoid approach) for surgical treatment of patients with meningoencephalocele of the lateral sphenoid recess.

[Intra-optic nerve and chiasmal abscess caused by methicillin-resistant Staphylococcus aureus (a case report and literature review)]. / Abstsess intrakranial'noi chasti zritel'nogo nerva i khiazmy, vyzvannyi metitsillinorezistentnym zolotistym stafilokokkom (klinicheskoe nabliudenie i obzor literatury).

A 27-year-old immunocompetent male with headache, transient polydipsia, and polyuria suddenly developed visual impairment (predominantly in the left eye) and, 2 days later, left-sided amaurosis. MRI in T1, T2, DWI, and FLAIR modes revealed a space-occupying lesion of the left intracranial optic nerve and chiasm. According to the clinical X-ray picture, malignant chiasmal glioma was suspected; another and less likely variant was lymphoma. An open biopsy of the space-occupying lesion of the chiasmal-sellar region revealed purulent-necrotic masses. Material from the operative wound was positive for a Staphylococcus aureus strain. The polymerase chain reaction of a cerebrospinal fluid sample revealed methicillin-resistant Staphylococcus aureus. The patient underwent systemic and intrathecal antibiotic therapy with linezolid and vancomycin, respectively, with a good clinical effect: there was an improvement in the vision in a right single sighted eye and normalization of the cerebrospinal fluid composition.

[Preoperative and postoperative endocrine disorders associated with pituitary stalk injuries caused by suprasellar growing tumors]. / Éndokrinnye rasstroistva do i posle operatsii pri razlichnykh porazheniiakh steblia gipofiza supraselliarno rastushchimi opukholiami.

The pituitary stalk (PS) is a relatively thin bundle connecting the hypophyseal stalk to the pituitary gland; it consists of both axons of the hypothalamic nuclei (terminating in the neurohypophysis) and the system of portal vessels. Compression of the PS by a space-occupying lesion or its transection (forced or intended) during surgery may lead to the development of endocrine disorders: hypopituitarism, diabetes insipidus, and hyperprolactinemia. The modern literature lacks studies evaluating the severity of endocrine disorders depending on the PS condition before and after surgery. PURPOSE: The study purpose was to investigate endocrine disorders in patients with sellar region (SR) tumors and the PS that was compressed before surgery and preserved or transected during a neurosurgical intervention. MATERIAL AND METHODS: The study included 139 patients with various SR tumors. In 82 patients, a preoperatively compressed PS was preserved (41 patients with hormonal inactive adenoma (HIA) and 41 patients with suprasellar meningioma); in 57 patients, the PS was transected during surgery (46 patients with pituitary stalk craniopharyngioma and 11 patients with hormonally inactive endosuprasellar pituitary adenoma). The hormonal status (PRL, TSH, LH, FSH, fT4, cortisol, testosterone, or estradiol) was examined in all patients both before and after surgery. RESULTS: Hyperprolactinemia was preoperatively detected in 37% of patients with tumors compressing the PS. Elimination of PS compression (tumor resection) led to normalization of the PRL level in most patients and was not accompanied by aggravation of hypopituitarism symptoms. Transection of the PS caused panhypopituitarism in 100% of patients and diabetes insipidus in 93% of cases. After transection of the PS, hyperprolactinemia did not develop in 59% of patients with craniopharyngiomas (CPs) and 82% of patients with HIA. CONCLUSIONS: Given the difference in symptoms associated with compression and surgical transection of the PS, we believe that these two concepts should be clearly distinguished. The PS compression syndrome includes primarily hyperprolactinemia (37% of cases); elimination of PS compression leads to normalization of the PRL level in most patients and is not accompanied by aggravation of hypopituitarism symptoms. The PS transection syndrome in patients with CP and HIA led to the development of panhypopituitarism in all patients and permanent diabetes insipidus in most of them. The causes of the absence of hyperprolactinemia in many patients with PS transection require further research. The surgeon planning intraoperative PS transection to increase the radicality of surgery should be well informed about the consequences of this procedure for the patient's endocrine status.

[The use of platelet gel for repair of a cerebrospinal fluid fistula of the skull base (a case report and literature review)]. / Primenenie trombotsitarnogo gelia dlia plastiki likvornoi fistuly osnovaniia cherepa (sluchai iz praktiki i obzor literatury).

Nasal liquorrhea is a serious problem in surgery of skull base tumors, which is associated with a high risk of purulent-septic complications. This paper presents a case of successful repair of a cerebrospinal fluid fistula with an autologous platelet gel in the postoperative period after removal of meningioma of the anterior cranial fossa base, which was accompanied by a purulent-inflammatory complication in the surgical wound area.

[The extended endoscopic endonasal transsphenoidal approach in surgery for epidermoid cysts of the chiasmatic region]. / Ispol'zovanie rasshirennogo transsfenoidal'nogo éndoskopicheskogo éndonazal'nogo dostupa v khirurgii épidermoidnykh kist khiazmal'noi oblasti.

Surgical treatment for epidermoid cysts of the chiasmatic region is a challenge because of the tendency to a massive spread of epidermoid masses through the cerebrospinal fluid pathways and a significant lesion deviation from the midline. PURPOSE: To analyze capabilities of the extended endoscopic endonasal transsphenoidal approach in surgery for epidermoid cysts. MATERIAL AND METHODS: The study included 6 patients with epidermoid cysts of the chiasmatic region who were operated on using the extended anterior endoscopic endonasal transsphenoidal approach at the Burdenko Neurosurgical Institute in the past 5 years. RESULTS: Epidermoid masses were completely removed in 5 patients; in none of the cases, complete removal of the epidermoid cyst capsule was achieved. There were no cases of vision deterioration and the development of new focal neurological symptoms. One female patient developed hypopituitary disorders in the postoperative period. There was no recurrence of epidermoid cysts during follow-up. CONCLUSION: Removal of epidermoid cysts of the chiasmatic region using the extended anterior endoscopic transsphenoidal approach may be an alternative to transcranial microsurgery.

[A rare case of diencephalic cachexia in an adult female with cranio-pharyngioma]. / Redkii sluchai razvitiia diéntsefal'noi kakheksii u vzrosloi zhenshchiny s kraniofaringiomoi.

Diencephalic cachexia (DС) is progressive weight loss despite a normal caloric intake and a satisfactory state of health, which is caused by hypothalamic lesions. This is a rare (about 100 cases were reported) and potentially fatal disorder of unknown pathogenesis. At present, there is no effective pharmacological therapy for the disorder. Cachexia may regress only if the tumor reduces in size, therefore the timely diagnosis and treatment are of vital importance for the patient. DС is typical of early childhood, and only a few cases have been reported in adults. We present a rare case of DС in a 24-year-old female with papillary craniopharyngioma.

[Cerebrospinal fluid rhinorrhea in primary treatment of large and giant prolactinomas with dopamine agonists]. / Nazal'naia likvoreia pri pervichnom lechenii bol'shikh i gigantskikh prolaktinom agonistami dofamina.

At present, pharmacological therapy of prolactinomas with dopamine agonists (DAs) is considered the treatment of choice. In most cases, giant prolactinomas respond to treatment with dopamine agonists and decrease in size during the first months of the treatment. One of the rare but dangerous complications of conservative treatment of prolactinomas with invasive growth is cerebrospinal fluid rhinorrhea. MATERIAL AND METHODS: We present a retrospective analysis of 15 patients with macropropactinomas who underwent surgery for cerebrospinal fluid rhinorrhea developed due to primary therapy with dopamine agonists at the Burdenko Neurosurgical Institute (BNI) in the period between 2005 and 2015. All patients had large and giant tumors (according to the classification adopted at the BNI). When cerebrospinal fluid rhinorrhea was detected, patients were hospitalized to the BNI for examination, detection of a CSF fistula, reconstruction of a defect, and resection (if possible) of the tumor. RESULTS: In the period between 2005 and 2015, 15 patients (8 males and 7 females) with prolactinomas of a large and giant size at the onset of conservative therapy underwent surgery for cerebrospinal fluid rhinorrhea at the BNI. All patients underwent transnasal reconstruction of a skull base defect, with 13 out of 15 patients undergoing simultaneous resection of the tumor. After tumor resection, reconstruction was performed using auto-fat, fascia, and glue (in 8 cases). In the remaining cases, apart from auto-fat, fascia, and glue, a mucoperiosteal flap and auto-bone were used. Fourteen patients were followe-up. In 13 cases, there was no relapse of cerebrospinal fluid rhinorrhea after skull base reconstruction. In 1 case, there was a relapse of cerebrospinal fluid rhinorrhea. CONCLUSION: Conservative treatment of patients with giant prolactinomas should be performed under regular control of ENT doctors and neurosurgeons for timely detection and surgical treatment of cerebrospinal fluid rhinorrhea.

[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.

[The use of intraoperative Doppler ultrasound in endoscopic transsphenoidal surgery].

INTRODUCTION: Doppler ultrasound (DUS) has been widely used in neurosurgical practice to diagnose various cerebrovascular diseases. This technique is used in transsphenoidal surgery to identify the localization of intracranial arteries when making an approach or during tumor resection. MATERIAL AND METHODS: To identify the cavernous segment of the internal carotid artery (ICA) and/or basilar artery during endoscopic transsphenoidal surgery, we used a combined device on the basis of a click line curette («Karl Storz¼) and a 16 MHz Doppler probe (Lassamed). The technique was used in 51 patients during both standard transsphenoidal surgery (23 cases) and transsphenoidal tumor resection through an extended approach (28 cases). RESULTS AND DISCUSSION: Doppler ultrasound was used in different situations: to determine a trajectory of the endonasal transsphenoidal approach in the absence of the normal anatomical landmarks (16 cases), to define the limits of safe resection of a tumor located in the laterosellar region (7), and to implement an extended transsphenoidal endoscopic approach (28). Intraoperative Doppler ultrasound enabled identification of the cavernous segment of the internal carotid artery in 45 cases and the basilar artery in 2 cases; a blood vessel was not found in 4 cases. Injury to the cavernous segment of the internal carotid artery was observed only in 1 case. CONCLUSION: The use of the described combined device in transsphenoidal surgery turned Doppler ultrasound into an important and useful technique for visualization of the ICA within the tumor stroma as well as in the case of the changed skull base anatomy. Its use facilitates manipulations in a deep and narrow wound and enables inspection of the entire surface of the operative field in various planes, thereby surgery becomes safer due to the possibility of maximum investigation of the operative field.

[Thyrotropin-producing adenomas and thyrotropic hyperplasia (clinical case reports and the review of the literature)]. / Tireotropinomy i tireotrofnaia giperplaziia (opisanie klinicheskikh sluchaev i obzor literatury).

An increased blood level of the thyroid stimulating hormone (TSH) is usually associated with primary hypothyroidism (PHT) but can also be observed in such rare cases as TSH-secreting pituitary tumor. The article describes four clinical cases of elevated TSH blood levels: 1) TSH-secreting pituitary adenoma with hyperthyroidism; 2) TSH-secreting adenoma with hypothyroidism; 3) hormonally inactive pituitary adenoma combined with primary hypothyroidism; 4) reversible thyrotropic hyperplasia. These clinical situations substantiate the importance of considering different diagnoses in a patient with a pituitary gland tumor associated with an increased TSH blood level.

[Combined surgical treatment of cavernous internal carotid artery pseudoaneurysm]. / Kombinirovannoe khirurgicheskoe lechenie lozhnoi anevrizmy kavernoznogo otdela vnutrennei sonnoi arterii.

We describe a clinical case of surgical treatment of a cavernous internal carotid artery (ICA) pseudoaneurysm that developed due to damage to the artery during transsphenoidal resection of pituitary adenoma. Clinically, the aneurysm presented with episodes of profuse epistaxis that required tight nasal packing. Given the presence of an open circle of Willis, the patient underwent staged surgery that included the creation of a high-flow extra-intracranial anastomosis, subsequent endovascular ICA occlusion at the pseudoaneurysm level using balloon-assisted coiling, and endoscopic debridement of the nasal cavity. The combined surgical treatment of this rare complication successfully excluded the pseudoaneurysm from the bloodstream, which led to complete regression of nasal bleeding.