Effect of Resection and Surgical Experience on Survival in Patients with Craniopharyngiomas: Endoscopic Transsphenoidal Surgery in Series of 31 Cases.

AIM: To share the surgical outcomes of 31 patients who underwent endoscopic endonasal transsphenoidal surgery (EETS) at a single center. MATERIAL AND METHODS: This retrospective analysis of 31 craniopharyngioma cases (2013-2022) with a minimum 6-month follow-up included demographic data, preoperative findings, postoperative resection volumes, recurrence rates, pathological diagnoses, and complications. RESULTS: Herein, 34 EETS surgeries were performed on 31 patients (12 males, 19 females). The presenting symptoms included visual loss (58%), hypopituitarism (54.8%), and diabetes insipidus (25.8%). Gross total resection was achieved in 87% of the patients, with 64.5% total and 22.5% near-total resection. Total resection prevented recurrences, contrasting with 75% recurrence in the subtotal resection patients (p=0.000). The primary patients showed 73.1% total resection, while only 20% of the recurrent patients achieved it (p=0.049). When comparing the first 16 cases with the last 15 cases in terms of surgical experience, the rates of resection (p=0.040) and recurrence-free survival (p=0.020) in the last 15 cases were statistically significant. Patients with preoperative visual loss demonstrated 94.4% improvement or stability postoperatively. Postoperative complications included hypopituitarism (71.4%), permanent diabetes insipidus (60.8%), worsening vision (6.5%), cerebrospinal fluid leakage (9.7%), meningitis (6.5%), and a 3.2% perioperative mortality rate. CONCLUSION: This study underscores the role of surgical resection in craniopharyngiomas, emphasizing the impact of surgical experience on recurrence-free survival. Primary surgery, with minimal complications and maximal resection, is crucial in managing recurrence challenges. Endoscopic endonasal transsphenoidal surgery, particularly in experienced centers, offers advantages such as panoramic vision and access to the third ventricle base, facilitating total and near-total resection and extending recurrence-free survival.

Microsurgical anatomy of the isthmic cingulum: a new white matter crossroad and neurosurgical implications in the posteromedial interhemispheric approaches and the glioma invasion patterns.

ABTRACT: The dichotomy of the cingulum bundle into the dorsal supracallosal and ventral parahippocampal parts is widely accepted; however, the retrosplenial component with its multiple alternative connections has not been revealed. The aim of this study was to delineate the microsurgical anatomy of a connectionally transition zone, the isthmic cingulum, in relation to the posteromedial interhemispheric access to the atrium and discuss the relevant patterns of glioma invasion on the basis of its fiber connections. White matter (WM) fibers were dissected layer by layer in a medial-to-lateral, lateral-to-medial, and posterior-to-anterior fashion. All related tracts and their connections were generated using deterministic tractography. The magnetic resonance imaging (MRI) tractography findings were correlated with those of fiber dissection. A medial parieto-occipital approach to reach the atrium was performed with special emphasis on the cingulate isthmus and underlying WM connections. The isthmic cingulum, introduced as a retrosplenial connectional crossroad for the first time, displayed multiple connections to the splenium and the superior thalamic radiations. Another new finding was the demonstration of lateral hemispheric extension of the isthmic cingulum fibers through the base of the posterior part of the precuneus at the base of the parieto-occipital sulcus. The laterally crossing cingulum fibers were interconnected with three distinct association tracts: the middle longitudinal (MdLF), the inferior frontooccipital fasciculi (IFOF), and the claustro-cortical fibers (CCF). In the process of entry to the atrium during posterior interhemispheric approaches, the splenial and thalamic connections, as well as the laterally crossing fibers of the isthmic cingulum, were all in jeopardy. The connectional anatomy of the retrosplenial area is much more complicated than previously known. The isthmic cingulum connections may explain the concept of interhemispheric and medial to lateral cerebral hemisphere invasion patterns in medial parieto-occipital and posteromesial temporal gliomas. The isthmic cingulum is of key importance in posteromedial interhemispheric approaches to both: the atrium and the posterior mesial temporal lobe.

Use of 3-Dimensional Modeling and Augmented/Virtual Reality Applications in Microsurgical Neuroanatomy Training.

BACKGROUND: Understanding the microsurgical neuroanatomy of the brain is challenging yet crucial for safe and effective surgery. Training on human cadavers provides an opportunity to practice approaches and learn about the brain's complex organization from a surgical view. Innovations in visual technology, such as virtual reality (VR) and augmented reality (AR), have immensely added a new dimension to neuroanatomy education. In this regard, a 3-dimensional (3D) model and AR/VR application may facilitate the understanding of the microsurgical neuroanatomy of the brain and improve spatial recognition during neurosurgical procedures by generating a better comprehension of interrelated neuroanatomic structures. OBJECTIVE: To investigate the results of 3D volumetric modeling and AR/VR applications in showing the brain's complex organization during fiber dissection. METHODS: Fiber dissection was applied to the specimen, and the 3D model was created with a new photogrammetry method. After photogrammetry, the 3D model was edited using 3D editing programs and viewed in AR. The 3D model was also viewed in VR using a head-mounted display device. RESULTS: The 3D model was viewed in internet-based sites and AR/VR platforms with high resolution. The fibers could be panned, rotated, and moved freely on different planes and viewed from different angles on AR and VR platforms. CONCLUSION: This study demonstrated that fiber dissections can be transformed and viewed digitally on AR/VR platforms. These models can be considered a powerful teaching tool for improving the surgical spatial recognition of interrelated neuroanatomic structures. Neurosurgeons worldwide can easily avail of these models on digital platforms.

Comparison of Electrophysiological and Radiological Subthalamic Nucleus Length and Volume.

AIM: To investigate the surgical value of MER recordings and improve surgical technique by demonstrating the consistency between preoperative radiological STN volume and intraoperative neurophysiological STN length. MATERIAL AND METHODS: Sixty-one patients with PD were enrolled. The volumes of the STN were measured using magnetic resonance images 3-dimensional volume reconstructions of stereotactic magnetic resonance images. MER were performed in all patient and the maximal electrophysiologic length of the STN was recorded each patient. In the postoperative period, the permanent electrode was modeled and reconstructed in 3D, and the longest distance traveled in the STN was calculated. RESULTS: A total of 61 patients who underwent surgery between 2012-2022 were included in the study. Thirty-six (59%) of the patients were male, and 25 (41%) were female. A total of 122 STNs were performed with 166 electrodes. The most common end alignment used was center with 86. STN length averaged 4.9 mm (0-10.5 mm). The mean STN volume was 0.11 cm3. The STN Volume of men were significantly higher than women. The STN Length, Volume, and the target MER length showed a positive correlation significantly. CONCLUSION: With radiological advances, it is possible to better visualize the target points and define the boundaries better, and direct methods can be used more in making targeting plans. MER records obtained during surgery and STN dimensions in presurgical planning show compatibility, and it is seen that there may be differences between the right and left sides because of brain shifting. Although radiology is increasingly providing better support, electrophysiological recordings provides real-time information on the electrodes? locations and give the opportunity to surgical team choosing alternative target.

Results of Endoscopic Surgery in Patients with Pituitary Adenomas : Association of Tumor Classification Grades with Resection, Remission, and Complication Rates.

OBJECTIVE: The endoscopic endonasal transsphenoidal approach is a widely-used method for the surgical treatment of pituitary adenomas. We aimed to evaluate the results of endoscopic surgery by comparing preoperative classification methods and investigating their relationship with postoperative resection and remission rates and complications. METHODS: We retrospectively reviewed the medical records of 236 patients (118 males) who underwent surgery for pituitary adenomas. Preoperative Knosp classification, tumor size (TS), suprasellar extension (SSE), postoperative resection and remission rates, and complications were evaluated. RESULTS: The follow-up period was 3 months to 6 years. The patients' ages ranged between 16 and 84 years. Endocrinologically, 114 patients (48.3%) had functional adenoma (FA), and 122 patients (51.7%) had non-functional adenoma (NFA). Among the FA group, 92 (80.7%) showed remission. A statistically significant difference was found between patients with and without remission in terms of the Knosp, TS, and SSE classifications (p<0.01). Knosp, TS, and SSE classification grades were found to be correlated with the resection rates (p<0.01). Meningitis was seen in seven patients (3.0%), diabetes insipidus in 16 (6.9%; permanently in two [0.9%]), and rhinorrhea in 19 (8.1%). Thirty-six patients (15.3%) developed pituitary insufficiency and received hormone replacement therapy. CONCLUSION: The resection categories and remission rates of FAs were directly proportional to the adenoma sizes and Knosp grades, while the degree of suprasellar growth further complicated resection and remission rates. Adenoma sizes less than 2 cm and SSEs less than 1 cm are associated with favorable remission and resection rates.