Thromboelastometry-Based Prophylaxis for Venous Thromboembolism in the Acute Period Following Isolated Severe Traumatic Brain Injury.

Objective: Traumatic brain injury (TBI) is an independent risk factor for venous thromboembolism (VTE). This study aimed to determine the optimal timing for initiating pharmacological thromboprophylaxis for VTE in patients with isolated severe TBI using rotational thromboelastometry (ROTEM). Methods: This single-center observational study enrolled 115 patients aged 18-59 years with isolated severe TBI within the first 48 hours after injury. Results: Using ROTEM data, we identified hypercoagulation due to an increase in clot density (MCF EXTEM >72), which was attributed to fibrinogen (MCF FIBTEM >25). From day 4, hypercoagulation occurred in 14.8% of the patients. By day 7, these changes were observed in 85.2% of patients. According to brain computed tomography findings, patients who received early VTE chemoprophylaxis on days 3-4 after severe TBI did not experience progression of hemorrhagic foci. Conclusion: Our results emphasize the clinical significance of thromboelastometry in patients with isolated severe traumatic TBI. Anticoagulant prophylaxis started on 3-4 days after severe TBI was relatively safe, and most patients did not experience hemorrhagic foci progression. The data acquired in this study may enable the optimization of VTE chemoprophylactic approaches, thereby reducing the associated risks to patients.

Assessing the reliability of zygomatic bone landmarks as guides to reach the inferior orbital fissure in orbitozygomatic osteotomy: anatomical study of 83 human skulls.

To perform an adequate orbitozygomatic craniotomy, it is very important that the bone cut which passes through the body of the zygoma reaches the inferior orbital fissure (IOF). To reach the IOF, two surface landmarks on the body of the zygoma are described: a point located directly superior to the malar eminence and the zygomaticofacial foramen. The article explores the reliability of these landmarks and three other alternative points to reach the IOF. Eighty-three adult skulls were used in this study. The IOF dimensions and the relationship with the malar eminence, the point superior to the malar eminence, the zygomaticofacial foramen, and 3 alternative points (E, C, F) were analyzed. The malar eminence was unacceptable for use as a guide to the IOF. The point superior to the malar eminence was also unacceptable as a guide as only 9.4% and 10.9% were in the projection of the IOF on the right and left, respectively. 59.7% of the total zygomaticofacial foramina fell in the IOF projection. The point F fell in the projection of the IOF in 98.8% and 100.0% on the right and left, respectively. The use of the malar eminence as a guide to reach the IOF is unreliable in one third of cases as it is not easily identified intraoperatively in these cases. The zygomaticofacial foramen cannot be considered a reliable surgical landmark to reach the IOF. The authors recommend using a novel landmark which may be identified as a midpoint between intersections of the anterior and posterior margins of the zygomatic frontal process on a line extending from the inferior margin of the zygomatic arc. This point is reliable in 98.8-100% of cases.

Effects of exogenous factors on spatial accuracy in neurosurgery.

The study aimed to assess the effect of exogenous factors such as surgeon posture, surgical instrument length, fatigue after a night shift, exercise and caffeine consumption on the spatial accuracy of neurosurgical manipulations. For the evaluation and simulation of neurosurgical manipulations, a testing device developed by the authors was used. The experimental results were compared using nonparametric analysis (Wilcoxon test) and multivariate analysis, which was performed using mixed models. The results were considered statistically significant at p < 0.05. The study included 11 first-year neurosurgery residents who met the inclusion criteria. Hand support in the sitting position (Wilcoxon test p value = 0.0033), caffeine consumption (p = 0.0058) and the length of the microsurgical instrument (p = 0.0032) had statistically significant influences on the spatial accuracy of surgical manipulations (univariate analysis). The spatial accuracy did not significantly depend on the type of standing position (Wilcoxon test p value = 0.2860), whether the surgeon was standing/sitting (p = 0.1029), fatigue following a night shift (p = 0.3281), or physical exertion prior to surgery (p = 0.2845). When conducting the multivariate analysis, the spatial accuracy significantly depended on the test subject (p < 0.0001), the use of support during the test (p = 0.0001), and the length of the microsurgical instrument (p = 0.0397). To increase the spatial accuracy of microsurgical manipulations, hand support and shorter tools should be used. Caffeine consumption in high doses should also be avoided prior to surgery.

Hippocampal Dosimetry and Mnemonic Function Changes After Stereotactic Irradiation of Cavernous Sinus Meningiomas.

INTRODUCTION: It is believed that hippocampal exposure plays a major role in the development of memory disorders after cranial irradiation. This effect is evident in whole-brain irradiation and is less certain in local irradiation of intracranial targets. The present study aims to clarify the dosimetric features and dynamics of memory functions after local irradiation of the hippocampus when treating cavernous sinus meningiomas. METHODS: The study included 28 patients (24 females and 4 males) with cavernous sinus meningiomas diagnosed according to typical clinical and radiological findings. The mean age was 52 years (30-65 years). Stereotactic radiotherapy in standard fractionation regimen (54 Gy total dose) was the primary treatment in all patients. Patients underwent memory testing (ability to reproduce and recognize) using a previously developed and validated methodology at standard time points: before the start of radiotherapy, at the end of the course, and 6 and 12 months after treatment. Hippocampal dose, dynamics of memory function, and their possible relationship were evaluated. RESULTS: In total, 28 cavernous sinus meningiomas (15 left-sided and 13 right-sided) were treated. The mean target volume was 24.0 ccm (8.2 ccm to 53.8 ccm). Twelve months after radiotherapy, there was an increase in the median total number of recognition errors from 6.5 [4;11] to 9.5 [5;12], p=0.025, the median number of "old-similar" errors from 2 [1;3.25] to 3 [1.75;5], p=0.021, and the median number of "similar-old" errors from 3 [1;5] to 5.5 [3;7], p<0.001. The number of reproduction errors did not increase. A moderate correlation (p = 0.03, correlation coefficient = 0.41) was found between the dose to 10% of the ipsilateral hippocampus and the total number of reproduction errors at the end of the course. No other significant correlations were found at the end of radiotherapy and six and 12 months after it. CONCLUSION: Thus, even partial lateralized exposure of the hippocampus during irradiation of the cavernous sinus meningiomas affects its function in the form of specific pattern separation type disturbances, which are detected as early as 12 months after the impact. The hippocampus in this treatment should be considered as a critical structure whose sensitivity to irradiation requires additional assessment.

Pineal Cyst-Related Aqueductal Stenosis as Cause of Intractable Headaches in Nonhydrocephalic Patients.

BACKGROUND: Pineal cysts (PCs) are histologically benign lesions of the pineal gland. Although the majority of PCs are asymptomatic, some cases are ambiguous and accompanied by nonspecific symptoms of variable severity. We suggested that disabling headache in nonhydrocephalic patients with PCs is associated with cerebral aqueduct (CAq) stenosis. METHODS: A retrospective analysis was conducted in patients with PCs suffering from headache without secondary hydrocephalus who underwent surgical resection at Burdenko Neurosurgery Center between 1995 and 2016. All available medical records and radiographic images were retrospectively assessed in these patients. The comparison groups included 22 patients with nonoperated PCs and 25 healthy individuals. Specific magnetic resonance imaging measures were selected to assess the morphometry of the CAq and degree of the stenosis. RESULTS: In 25 patients (82%) we observed clinical improvement after surgery in a follow-up period. Among those with improvement, 10 of them (40%) experienced total relief and 15 of them (60%) had marked headache diminishment. In 5 patients the headache remained persistent. The preoperative rostral CAq diameter appeared to be significantly narrower (P = 0.0011045), and the preoperative rostral/caudal diameter ratio (Rd/Cd) was found to be lower (P = 0.004391) in patients who recovered from headache versus those who did not. CONCLUSION: The results indicate a statistically significant relationship between the changes in the CAq morphometrics and the clinical outcome in postoperative period. Surgical removal of symptomatic pineal cysts in patients without hydrocephalus can be considered as an effective treatment. However, a thorough preoperative examination and patient selection should be conducted in every case.