Sensitivity of three-dimensional time-of-flight 3.0 ​T magnetic resonance angiography in visualizing the number and course of lenticulostriate arteries in patients with insular gliomas.

Background: Neurosurgical resection of insular gliomas is complicated by the possibility of iatrogenic injury to the lenticulostriate arteries (LSAs) and is associated with devastating neurological complications, hence the need to accurately assess the number of LSAs and their relationship to the tumor preoperatively. Methods: The study included 24 patients with insular gliomas who underwent preoperative 3D-TOF MRA to visualize LSAs. The agreement of preoperative magnetic resonance imaging with intraoperative data in terms of the number of LSAs and their invasion by the tumor was assessed using the Kendall rank correlation coefficient and Cohen's Kappa with linear weighting. Agreement between experts performing image analysis was estimated using Cohen's Kappa with linear weighting. Results: The number of LSAs arising from the M1 segment varied from 0 to 9 (mean 4.3 â€‹± â€‹0.37) as determined by 3D-TOF MRA and 2-6 (mean 4.25 â€‹± â€‹0.25) as determined intraoperatively, κ â€‹= â€‹0.51 (95% CI: 0.25-0.76) and τ â€‹= â€‹0.64 (p â€‹< â€‹0.001). LSAs were encased by the tumor in 11 patients (confirmed intraoperatively in 9 patients). LSAs were displaced medially in 8 patients (confirmed intraoperatively in 8 patients). The tumor partially involved the LSAs and displaced them in 5 patients (confirmed intraoperatively in 7 patients), κ â€‹= â€‹0.87 (95% CI: 0.70-1), τ â€‹= â€‹0.93 (p â€‹< â€‹0.001). 3D-TOF MRA demonstrated high sensitivity (100%, 95% CI: 0.63-1) and high specificity (86.67%, 95% CI: 0.58-0.98) in determining the LSA-tumor interface. Conclusions: 3D-TOF MRA at 3T demonstrated sensitivity in determining the LSA-tumor interface and the number of LSAs in patients with insular gliomas.

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.

Complication avoidance: resection of the insular glioma complicated by iatrogenic injury to the lenticulostriate artery.

BACKGROUND: Neurosurgical resection of insular gliomas is complicated by the risk of iatrogenic injury to lenticulostriate arteries (LSAs). METHOD: We provide a description, figures, and a video to illustrate the clinical case in which the LSA was damaged during the resection of insular glioma. Cadaveric dissection from our anatomical laboratory and our 3D anatomical model provided relevant surgical anatomy of the insula. CONCLUSION: Proximal dissection of the Sylvian fissure up to the most lateral LSA, the emergence of the beige putamen, and the lenticulostriate veins are anatomic landmarks that allow reducing the risk of damaging the intraparenchymatous segment of the LSAs.

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.

Microsurgical Treatment of Colloid Cysts of the Third Ventricle.

BACKGROUND: This study analyzes the results of surgical treatment in 377 patients with colloid cysts (CCs) of the third ventricle who were treated at the Burdenko Neurosurgery Institute from 1981 to 2015. Operations were performed by a single surgeon (the first author of the article). METHODS: The transcallosal approach was used to remove CCs in 97% of cases. Total cyst removal was performed in 96% of cases (in 4% of cases, a small cyst capsule fragment was left on the veins and fornix); in 3 cases, the cyst recurred, which required its repeated removal. RESULTS: Hydrocephalus symptoms regressed in 98% of patients. The most frequent complications in the early postoperative period were memory impairments of varying severity, with a tendency to regress by the time of discharge. Two patients had an intraventricular hematoma, which required operative exploration in 1 patient. There were 4 cases of meningitis (including 1 shunt-associated meningitis) and 5 cases of transient pyramidal insufficiency. CONCLUSIONS: We made a preliminary assessment of the reasonability of the infratentorial supracerebellar approach for removal of CCs in 10 cases.

Intraosseous Metastasizing of Pineoblastoma into the Anterior Skull Base, Calvarial Bones, and Vertebrae.

Pineoblastoma is a rare malignant tumor of the central nervous system (CNS), which arises from the parenchyma of the pineal gland. It is characterized by aggressive clinical behavior and frequent metastases along the craniospinal axis. Extraneural metastases may occur due to surgical seeding of tumor cells beyond the dura and/or hematogenous spread, ventriculoperitoneal shunting, or through Batson's plexus. To our knowledge, only six documented cases of intraosseous metastases of pineoblastoma are described in the literature. A 23-year-old female patient presented with clinical and radiological symptoms of a pineal tumor causing secondary hydrocephalus. After initial surgical treatment, chemotherapy, and local radiotherapy with craniospinal irradiation, she developed multiple metastases affecting the anterior skull base, intracranial meninges, frontal bone, and finally, the entire vertebral column. The patient received surgical treatment for the anterior skull base metastasis, repeated irradiation of the neuraxis, radiosurgical and radiotherapeutic procedures, and chemotherapy. The patient survived 57 months after the primary disease manifestation and died of multiple metastases. This presented case is the first known description of metastasis of pineoblastoma in the anterior cranial base. Multiple intracranial metastases were suppressed using CyberKnife radiation treatment and chemotherapy until massive involvement of spinal column occurred. Interestingly, no signs of brain radiation necrosis after repeated radiation treatments were observed, and the patient developed only moderate neurocognitive decline.

A novel device for hands-free positioning and adjustment of the surgical microscope.

The authors have developed a novel device, which they have named Mari, that allows hands-free utilization of the surgical microscope. The device is attached to the eyepieces of a multifunction counterweight-balanced surgical microscope and consists of a metallic holder with supportive plates that facilitate interaction between the device and surgeon's head. On the holder are installed 1) an electric switch, which allows the surgeon to release the microscope's magnetic clutches, allowing movement of the microscope along the x, y, and z axes as well as the rotational and diagonal ones, and 2) a joystick at the level of the surgeon's mouth for adjustment of focus and zoom. The authors report on the initial experience with the use of the device at the Burdenko Neurosurgery Institute, where the senior author used it in approximately 600 procedures between 2006 and 2012. The surgeries ranged in difficulty and in duration (from 20 minutes to 7 hours, median 2.5 hours). Use of the Mari device resulted in increased accuracy of the surgical manipulations and a reduction in the duration of surgery.

Microsurgical third ventriculostomy with stenting in intrinsic brain tumors involving anterior third ventricle.

OBJECTIVE: Microsurgical fenestration of the third ventricular floor performed in one session with resection of deep seated tumors has been recently demonstrated as an approach to specifically address the concomitant obstructive hydrocephalus. As with endoscopic third ventriculostomy, occlusion of the stoma may result in progression of the obstructive hydrocephalus. In order to provide reliable communication between the basal cisterns and ventricles, we propose stenting of the stoma in cases of direct surgical approach to deep seated tumors. METHODS: After performing tumor resection through the anterior transcallosal approach, premamillar and Liliequist's membranes were identified and fenestrated. A silicon stent was inserted into the prepontine cistern through the fenestrated floor of the third ventricle; the stent connected the third and lateral ventricles with the basal cisterns. RESULTS: Microsurgical ventriculostomy of the third ventricle and stenting of the stoma was performed in 9 patients simultaneously with tumor resection (5 cases), open biopsy (3 cases), or microsurgical dissection of severe adhesions at the level of Monro foramina (1 case). In 7 cases, the third ventricular floor was infiltrated with the tumor and obstruction of the aqueduct persisted after tumor surgery; in 2 patients, high risk of reocclusion at the level of Monro foramen was expected. Stenting of the ventricular system provided patency of the stoma and Monro foramen. None of the patients required a shunt postoperatively. The follow-up time ranged from 3 to 22 months. CONCLUSION: Microsurgical fenestration of the third ventricle floor combined with stoma stenting can be a viable option for hydrocephalus control.

Intraoperative direct third ventriculostomy and aqueductal stenting in deep-seated midline brain tumor surgery.

OBJECTIVE: Surgical resection of deep-seated midline brain tumors does not always resolve obstruction of cerebrospinal fluid pathways, and an additional operation--ventricular shunting--is required. To prevent postoperative obstructive hydrocephalus, we combine tumor removal and internal ventricular shunting in 1 stage. METHODS: Between 2000 and 2006, 82 patients with deep-seated midline brain tumors (tumors of the third ventricle, pineal region, thalamus, upper brainstem, and superior half of the fourth ventricle) underwent 84 tumor resections with intraoperative internal ventricular shunting. Two types of intraoperative shunting were performed: direct third ventriculostomy with fenestration of the premammillary membrane of the third ventricle floor and Liliequist's membrane, 53 operations; and aqueductal stenting, 30 operations. In 1 patient, third ventriculostomy and aqueductal stenting were performed simultaneously. RESULTS: As most of the tumors had an infiltrative growth pattern, gross total tumor removal was achieved in only 31% of patients in this series. There were no fatal outcomes related to the surgery. Follow-up data were collected in 73 patients (89%) and ranged from 2 to 68 months (median, 16 months). Additional shunting because of inadequate function of stoma or stent was performed in 13 patients at various times after surgery (median, 30 days). The Kaplan-Meier survival analysis demonstrated that at 12 and 24 months the intraoperative direct third ventriculostomy success rates were 67 and 61%, respectively; aqueductal stenting success rates were 93% at both 12 and 24 months. CONCLUSION: Intraoperative direct third ventriculostomy and aqueductal stenting under direct visual control were found to be reliable methods of hydrocephalus management in patients with deep-seated midline brain tumors.

Principles of treatment of the pineal region tumors.

BACKGROUND: A pineal region tumor is an uncommon deep-seated, heterogeneous group of mass lesions of the brain, and the management strategy of any types of these tumors remains controversial. It is the purpose of this communication to present results of our experience in treating patients with these neoplasms. METHODS: From 1976 to 1999 about 700 patients with tumors of the pineal region and posterior third ventricle were managed at the Burdenko Neurosurgery Institute. In more than 330 cases the tumor was removed. In this paper we present results of 287 patients with histologically verified pineal region tumors for the period from 1976 to 1999. All of them had verified tumor histology, excluding only five cases in which stereotactic biopsy procedures were uninformative. There are four main groups of tumors: the germ cell tumors-87 (31%); the pineal parenchymal tumors-75 (27%); the glial tumors-77 (27%); and miscellaneous-43 (15%). There were 255 surgical procedures for tumor removal performed in 244 and stereotactically guided biopsies in 61 patients, 168 (58%) with obstructive hydrocephalus who underwent cerebrospinal fluid shunting. Radiation therapy was administered in 145 (51%) and chemotherapy in 16 patients. Follow-up data were collected in 209 cases (80%). Survival was calculated with the Kaplan-Meier product limit method. RESULTS: The occipital transtentorial and infratentorial supracerebellar approaches were the most commonly used on our series-138 (54%) and 87 (34%), respectively. In the remaining cases, subchoroidal approach, approach through the fourth ventricle, and the combined approaches were used. A total tumor removal was achieved in 148 operations (58%), subtotal in 74 (29%) and partial in 33 (13%). The projected 5-year and 10-year survival rates for patients with malignant pineal tumors, who received irradiation after tumor resection or underwent radiation therapy alone, were: 95% and 88% for pure germinomas, 80% and 50% for high grade gliomas, 44% and 0% for malignant pineal parenchymal tumors, and 20% and 0% for malignant germ cell tumors, respectively. CONCLUSIONS: Benign pineal tumors should be cured with surgery alone. Malignant tumors should be treated with aggressive resection followed with irradiation and chemotherapy. Pure germinomas, which are exquisitely radiosensitive, can be cured by conventional radiation therapy alone.