[Craniofacial tumors blood supply]. / Krovosnabzhenie kraniofatsial'nykh opukholei.

Because of the spread to different anatomical regions, craniofacial tumors (CFTs) usually receive blood supply from several arterial systems, and CFT removal is often accompanied by abundant blood loss. PURPOSE: The study purpose was to develop an algorithm of diagnostic angiography for planning surgical treatment of CFT patients. MATERIAL AND METHODS: Complex preoperative angiography was performed in 72 patients with craniofacial tumors, aged 10 to 78 years (mean age, 45.5 years), who underwent surgical treatment at the Burdenko Neurosurgical Institute in the period from 2012 to 2015. At the first stage, blood supply to tumors was quantified using SCT perfusion. Then, depending on an assessed degree of tumor vascularization, direct angiography or modern minimally invasive angiographic techniques (3D TOF HR MR angiography, SCT angiography) were applied. RESULTS: In 12 cases of hypervascular tumors, accessible afferents were preoperatively embolized through the external carotid artery, which was accompanied by an increase in the blood supply to tumors via alternative routes of the external and internal carotid arteries. The obtained data were used to plan the surgical approach. A comparative analysis of the SCT perfusion data and the expression level of endothelial markers in histological specimens revealed no significant correlation. CONCLUSION: The study demonstrated the importance of a comprehensive assessment of the blood supply to CFTs in planning of the surgical treatment and enabled the development of algorithms for preoperative angiographic diagnosis, depending on the baseline clinical and radiological data.

[Diffusion tensor imaging tractography and intraoperative neurophysiological monitoring in surgery of intracranial tumors located near the pyramidal tract].

BACKGROUND: Practical application of methods for intravital examination of the brain pathways, such as preoperative diffusion tensor imaging (DTI) tractography and intraoperative neurophysiological monitoring, facilitates safer resection of intracranial tumors located near the pyramidal tracts (PTs). PURPOSE: The study purpose was to investigate the relationships between intracerebral tumors of different histological nature and the pyramidal tract based on preoperative DTI tractography and various methods of intraoperative neurophysiological monitoring for intraoperative identification of the pyramidal tract, depending on different variants of the topographo-anatomic relationships between the pyramidal fascicle and the tumor. MATERIAL AND METHODS: The study included 29 patients with supratentorial tumors of a different histological structure. Of these, 2 patients had grade I tumors, 8 patients had grade II tumors, 4 patients had grade III tumors, 11 patients grade IV tumors, and 4 patients had brain metastases. The patients underwent preoperative DTI tractography with PT reconstruction and evaluation of the topographo-anatomic relationships between the pyramidal tract and the tumor (tract: intact, infiltrated, displaced). Neurophysiological monitoring (direct electrical stimulation in 24 patients and transcranial motor evoked potentials in 26 patients) was used during surgery. The strength of stimulating current for direct stimulation was varied from 10 to 30 mA. Postoperatively, the motor function was evaluated by using a 5-score scale, and the data were compared to the preoperative data. RESULTS: According to preoperative DTI tractography in patients with grade I-II gliomas, the corticospinal tracts were infiltrated in 2 cases, displaced in 3 cases, and intact in 5 cases. In patients with grade III-IV gliomas and metastases, the tracts were infiltrated in 8 cases, displaced in 4 cases, and intact in 7 cases. Motor responses evoked by direct electrical stimulation were obtained in 5 out of 6 patients with the pyramidal tract displaced by the tumor and in 7 out of 8 patients with the tract infiltrated by the tumor. In the case of the intact tract, the PT to tumor distance and the stimulus strength play an important role: responses were obtained in 4 out of 10 patients. In the case of transcranial motor evoked potentials (TCMEPs), no dynamics of the potential amplitude was detected in 17 out of 26 patients during surgery; a reduced TCMEP amplitude was detected in 9 patients. CONCLUSION: 1. Patients with an infiltrated or displaced pyramidal tract had significantly more often hemiparesis before surgery and aggravation of hemiparesis after the surgery compared to patients with an intact tract. 2. In the case of direct electrical stimulation of the PT, motor responses (according to preoperative DTI tractography) were significantly more often observed for the pyramidal tract infiltrated and displaced by the tumor. 3. A reduction in the motor neurologic deficit in the postoperative period was significantly more often observed for application of a larger current strength during direct electrical stimulation. 4. Persistence of the TCMEP amplitude during surgery is a reliable predictor for no aggravation of the motor neurological deficit after surgery. Postoperative aggravation of hemiparesis was significantly more often observed when TC MEPs decreased during surgery.

[3D-TOF MR-angiography with high spatial resolution for surgical planning in insular lobe gliomas].

UNLABELLED: Despite the obvious progress in modern neurosurgery, surgery for glial tumors of the insular lobe is often associated with a high risk of postoperative neurological deficit, which is primarily caused by damage to perforating arteries of the M1 segment of the middle cerebral artery. OBJECTIVE: The work is aimed at evaluating the effectiveness of high resolution time-of-flight (3D-TOF) MR angiography in imaging of medial and lateral lenticulostriate arteries and determining their relationship to tumor edge in patients with gliomas of the insula. MATERIAL AND METHODS: 3D-TOF MR angiography data were analyzed in 20 patients with primarily diagnosed cerebral gliomas involving the insula. All patients underwent non-contrast enhanced 3D-TOF MR angiography. In 6 cases, 3D-TOF MRA was performed before and after contrast enhancement. RESULTS: 3D-TOF angiography before intravenous contrast injection was capable of visualizing the medial lenticulostriate arteries in 19 patients (95% of all cases) and lateral lenticulostriate arteries in 18 patients (90% of all cases). Contrast-enhanced 3D-TOF angiography allows for better visualization of both the proximal and distal segments of lenticulostriate arteries. Three variants of relationship between the tumor and lenticulostriate arteries were identified. Variant I: the tumor grew over the arteries without their displacement in 2 cases (10% of the total number of observations); variant II: the tumor caused medial displacement of arteries without growing over them in 11 cases (55% of the total number of observations); variant III: the tumor partially grew over and displaced arteries in 2 cases (10%). In 25% of cases (5 patients), tumor was poorly visualized on 3D-TOF MR angiograms because their signal characteristics did not differ from those of the medulla (tumor tissue was T1 isointense). As a result, it was impossible to determine the relationship between the tumor and lenticulostriate arteries. CONCLUSION: High spatial resolution time-of-flight MR angiography can be recommended for preoperative imaging of lenticulostriate arteries to plan the extent of neurosurgical resection in patients with glial tumors of the insular lobe.

[SCT perfusion in the diagnosis of sellar and parasellar tumors].

UNLABELLED: The study is devoted to the use of a minimally invasive method of SCT perfusion for the differential diagnosis of sellar and pаrаsellar tumors. Given a wide differential diagnostic range of tumors occurring in this area, the tumor perfusion indicators were used as an auxiliary diagnostic criterion. MATERIAL AND METHODS: The study analyzed outcomes in 115 patients with various tumors of the sellar area who underwent surgery or biopsy for histological verification of the diagnosis. RESULTS: The statistically significant differences were obtained for certain groups of tumors based on the values of hemodynamic parameters (p<0.05) that enable, with a high confidence, making a conclusion on the histologic type of most tumors. CONCLUSION: These findings demonstrated that SCT perfusion is a highly informative method of the preoperative differential diagnosis of these tumors. The sensitivity and specificity of SCT perfusion in the study were 100% and 81.2%, respectively.

[Review of surgical treatment of insular gliomas: challenges and opportunities].

Intracerebral tumors of the insular lobe are quite frequent, however treatment of patients with this pathology still remains a challenging and controversial issue of neurosurgery. First of all, this is associated with the localization of tumors in the area of eloquent anatomical structures: M1--M2 segment of the middle cerebral artery, lenticulostriate arteries, basal ganglia, and internal capsule, which causes a high rate of postoperative complications in these patients. Most insular tumors are amenable for resection with a reasonable rate of postoperative complications, although most of the surgery-related complications resulting in substantial deficits are due to lesions of eloquent anatomical structures located in this compact anatomical space. Therefore, the aim of this work was to analyze the literature regarding the issues of clinical presentation, diagnosis, and aspects of surgical treatment of insular tumors.

[A correlation between diffusion kurtosis imaging and the proliferative activity of brain glioma].

UNLABELLED: The aim of the study was to assess the capabilities of diffusion kurtosis imaging (DKI) in diagnosis of the glioma proliferative activity and to evaluate a relationship between the glioma proliferative activity index and diffusion parameters of the contralateral normal appearing white matter (CNAWM). MATERIAL AND METHODS: The study included 47 patients with newly diagnosed brain gliomas (23 low grade, 13 grade III, and 11 grade IV gliomas). We determined a relationship between absolute and normalized parameters of the diffusion tensor (mean (MD), axial (AD), and radial (RD) diffusivities; fractional (FA) and relative (RA) anisotropies) and diffusion kurtosis (mean (MK), axial (AK), and radial (RK) kurtosis; kurtosis anisotropy (KA)) and the proliferative activity index in the most malignant glioma parts (p<0.05). We also established a relationship between the tensor and kurtosis parameters of CNAWM and the glioma proliferative activity index (p<0.05). RESULTS: The correlation between all the absolute and normalized diffusion parameters and the glioma proliferative activity index, except absolute and normalized FA and RA values, was found to be statistically significant (p<0.05). Kurtosis (MK, AK, and RK) and anisotropy (KA, FA, RA) values increased, and diffusivity (MD, AD, RD) values decreased as the glioma proliferative activity index increased. A strong correlation between the proliferative activity index and absolute RK (r=0,71; p=0.000001) and normalized values of MK (r=0.8; p=0.000001), AK (r=0.71; p=0.000001), RK (r=0.81; p=0.000001), and RD (r=-0.71; p=0.000001) was found. A weak, but statistically significant correlation between the glioma proliferative activity index and diffusion values RK (r=-0.36; p=0.014), KA (r=-0.39; p=0.007), RD (r=0.35; p=0.017), FA (r=-0.42; p=0.003), and RA (r=-0.41; p=0.004) of CNAWM was found. CONCLUSION: DKI has good capabilities to detect immunohistochemical changes in gliomas. DKI demonstrated a high sensitivity in detection of microstructural changes in the contralateral normal appearing white matter in patients with brain gliomas.