Preserving the cerebellar hemispheric tentorial bridging veins through a novel tentorial cut technique for supracerebellar approaches.

OBJECTIVE: The objective of this study was to describe the distribution pattern of cerebellar hemispheric tentorial bridging (CHTB) veins on the tentorial surface in a case series of perimedian or paramedian supracerebellar approaches and to describe a novel technique to preserve these veins. METHODS: A series of 141 patients with various pathological processes in different locations was operated on via perimedian or paramedian supracerebellar approaches by the senior author from July 2006 through October 2022 and was retrospectively evaluated. During surgery, the number and locations of all CHTB veins were recorded to establish a distribution map on the tentorial surface, divided into nine zones. Patients were classified into four groups according to the surgical technique used to manage CHTB veins: 1) group 1 consisted of CHTB veins preserved without intervention during surgery or no CHTB veins found in the surgical route; 2) group 2 included CHTB veins coagulated during surgery; 3) group 3 included CHTB veins preserved with arachnoid and/or tentorial dissection from the cerebellar or tentorial surface, respectively; and 4) group 4 comprised CHTB veins preserved using a novel tentorial cut technique. RESULTS: Overall, 141 patients were included in the study. Of these 141 patients, 38 were in group 1 (27%), 32 in group 2 (22.7%), 47 in group 3 (33.3%), and 24 in group 4 (17%). The total number of CHTB veins encountered was 207 during surgeries on one side. According to the distribution zones of the tentorium, zone 5 had the highest density of CHTB veins, while zone 7 had the lowest. Of the patients in group 4, 6 underwent the perimedian supracerebellar approach and 18 had the paramedian supracerebellar approach. There were 39 CHTB veins on the surface of the 24 cerebellar hemispheres in group 4. The tentorial cut technique was performed for 27 of 39 CHTB veins. Twelve veins were not addressed because they did not present any obstacles during approaches. During surgery, no complications were observed due to the tentorial cut technique. CONCLUSIONS: Because there is no way to determine whether a CHTB vein can be sacrificed without complications, it is important to protect these veins in supracerebellar approaches. This new tentorial cut technique in perimedian or paramedian supracerebellar approaches makes it possible to preserve CHTB veins encountered during supracerebellar surgeries.

The Comparison of General Characteristics and Early and Late Post-intervention Results in Patients With Trigeminal Neuralgia Secondary to Multiple Sclerosis and Idiopathic Trigeminal Neuralgia Treated With Radiofrequency Thermocoagulation.

Aim The aim of this study was to investigate possible differences (in terms of demographic structure, disease history, complaints, clinical findings, early and late treatment outcomes, and complications) between patients with idiopathic trigeminal neuralgia (ITN) and trigeminal neuralgia (TN) secondary to multiple sclerosis (MS) who were admitted to our clinic and underwent radiofrequency (RF) thermocoagulation procedure. Materials and methods Patients who underwent percutaneous radiofrequency thermocoagulation with a diagnosis of trigeminal neuralgia by a single neurosurgeon in a single neurosurgery clinic between January 2005 and January 2020 were included in this study. Patients were divided into two groups: idiopathic trigeminal neuralgia and trigeminal neuralgia secondary to multiple sclerosis (MSTN) according to their diagnosis. In our study, 215 TN patients who underwent 286 procedures were included. These patients were categorized according to age, sex, involved side, pain localization, and pain history. Postoperative complications were determined after each intervention. The early and late results of all interventions were evaluated, and the results were compared between both groups. All results were statistically analyzed. Results Considering the age of the patients, the mean age of the idiopathic group was higher than the multiple sclerosis group (58.18>49.46). In terms of the side of pain, bilateral involvement was significantly more common in the MS secondary group (1.48%<30.77%). There was no significant difference between the early results of both groups. In terms of remission periods, the pain-free period in the MS secondary group was significantly shorter than in the idiopathic group (mean value in months, 30.87>23.81). Conclusion The radiofrequency thermocoagulation of the trigeminal nerve is a highly effective, low-complication, reproducible procedure for trigeminal neuralgia, but the search for ways to improve the efficacy of treatment in MS patients should continue.

Three-Dimensional Modeling and Augmented and Virtual Reality Simulations of the White Matter Anatomy of the Cerebrum.

BACKGROUND: An understanding of the anatomy of white matter tracts and their 3-dimensional (3D) relationship with each other is important for neurosurgical practice. The fiber dissection technique contributes to this understanding because it involves removing the brain's white matter tracts to reveal their anatomic organization. Using this technique, we built freely accessible 3D models and augmented and virtual reality simulations of white matter tracts. OBJECTIVE: To define the white matter tracts of cadaveric human brains through fiber dissection and to make 2-dimensional and 3D images of the white matter tracts and create 3D models and augmented and virtual reality simulations. METHODS: Twenty cadaveric brain specimens were prepared in accordance with the Klingler method. Brain hemispheres were dissected step-by-step from lateral-to-medial and medial-to-lateral directions. Three-dimensional models and augmented reality and virtual reality simulations were built with photogrammetry. RESULTS: High-resolution 3D models and augmented reality and virtual reality simulations of the white matter anatomy of the cerebrum were obtained. These models can be freely shifted and rotated on different planes, projected on any real surface, visualized from both front and back, and viewed from various angles at various magnifications. CONCLUSION: To our knowledge, this is the first detailed study integrating various technologies (3D modeling, augmented reality, and virtual reality) for high-resolution 3D visualization of dissected white matter fibers of the entire human cerebrum.

Retrospective Analysis and Comparison of 48 Intracranial Meningioma Cases As Two Groups According to Their Size.

Objective This study aims to examine the possible demographic, clinical, and surgical differences between giant and smaller meningiomas. Materials and Methods Forty-eight meningioma patients who were operated on in our clinic between 2016-2020 were included in our study. Fourteen meningiomas larger than 5 cm in diameter were defined as giant meningiomas and placed in group 1. Thirty-four remaining meningiomas, with sizes less than 5 cm, were placed in group 2. These patients were evaluated regarding age, sex, localization, symptoms and neurological findings, surgical results, histopathology, and postoperative results. Results The most common localization in group 1 was falcine-parasagittal, whereas in group 2 it was convexity. Simpson's grade I resection rate in group 1 was 35.71%, while in group 2 this rate was 67.65%. In histopathological examination, transitional type meningiomas (35.71%) were the most common in group 1, whereas fibrous type meningiomas (32.35%) were seen the most in group 2. Group 1 Karnofsky Performance Scale score average was 75.71 preoperatively and 85.71 postoperatively. In group 2, the preoperative and postoperative average was 97.35 and 96.76, respectively. The comparative statistical analysis reflects that: A) Resection rates were significantly lower in the giant meningioma group. B) Similarly, Karnofsky Performance Scale scores were also lower than group 2. C) When statistical comparisons were made according to sex, age, localization, histopathological results, postoperative complications, and recurrence rates, no significant differences were observed. Conclusion The term "Giant Meningioma" is a type of distinction that is frequently made in the literature. However, the single major difference we see in our study was the surgical results. The general condition of patients before and after surgery may be more critical than others in giant meningiomas. Although surgical resection is the main form of treatment in giant meningiomas, the risks arising from the size of the tumor should be taken into account, and necessary plans should be made for a successful surgical intervention.