The pineal region presents considerable challenges for neurosurgical interventions owing to its deep anatomical location and the intricate network of critical neurovascular structures that encase it. The capacity to conduct effective and safe neurosurgical procedures in this area necessitates a comprehensive understanding of anatomical variations. This study aims to conduct an in-depth analysis of radiologic measurements pertinent to accessing the pineal region, alongside their supported by qualitative cadaveric dissections. The supracerebellar infratentorial (SCIT) approach, occipital transtentorial (OT) approach, and posterior interhemispheric (PIH) approach were performed on four cadaveric heads (eight sides). All dissections were performed with the head positioned to simulate the orientation employed in the operating room. Magnetic resonance imaging (MRI) scans from 50 male to 50 female patients were also retrospectively assessed. Descriptive statistics were presented for the quantitative data. MRI analysis of 100 adult subjects revealed a mean tentorial angle of 31.5° (range: 14.4–47.7°), indicating substantial anatomical variability. Measurements from external landmarks to the pineal gland and tentorium were quantified to assist in surgical planning. The Torcular Herophili was found to exhibit variable vertical positioning, and its distance from the inion was measured radiologically. These findings were categorized into distinct morphometric types based on tentorial inclination and torcular location. Cadaveric dissections were performed in surgical positions simulating SCIT, OT, and PIH approaches, and were used to qualitatively illustrate key anatomical corridors. Each dissection demonstrated the spatial relationships among the tentorium, splenium, deep venous system, and surrounding neurovascular structures, consistent with the anatomical context of the radiologic measurements. In neurosurgical practice, a lesion’s location is a critical determinant in selecting the approach for addressing pineal region lesions, given the complex microsurgical anatomy and deep positioning of these structures. Additionally, conducting thorough radiologic examinations during the preoperative phase is essential in informing the choice of surgical approach. We posit that employing radiologic measurements and identifying vascular variations will lead to reduced complication rates.

Background and Objectives: Endoscope-assisted posterior fossa decompression with duraplasty (PFDD) is a minimally invasive alternative treatment for Chiari I malformation; however, its comparative effectiveness remains unclear. Therefore, this study aimed to compare the outcomes of conventional open decompression with those of endoscope-assisted minimally invasive decompression combined with duraplasty to assess the balance between limited surgical exposure and associated technical challenges. Materials and Methods: This retrospective single-center study compared 22 patients who underwent endoscope-assisted PFDD with a historical cohort of 16 patients treated with conventional open PFDD. Patients with C1-2 instability, prior craniovertebral surgery, or concomitant pathology requiring an alternative surgical strategy were excluded. The clinical outcomes, radiological findings, surgical variables, and complications were analyzed. Results: Clinical improvement, overall recovery, and 3-month Chicago Chiari Outcome Scale (CCOS) scores were comparable between the groups. The endoscopic group had higher CCOS scores at discharge. Syrinx resolution rates were similar, whereas postoperative cisterna magna expansion was more limited in the endoscopic cohort. The endoscopic approach was associated with a significantly shorter incision length and earlier mobilization. The rates of complications, including pseudomeningocele, cerebrospinal fluid fistula, and wound infection, did not differ significantly between the groups. Conclusions: Endoscope-assisted PFDD may be a less invasive alternative with comparable short-term clinical and radiological outcomes. Despite the technical challenges related to a limited working corridor, it can be considered a feasible option for selected patients.

To present a decade-long single-center experience with neonatal meningomyelocele (MMC) and to emphasize the impact of surgical timing and concomitant anomalies in these neonates. Neonates with MMC between 2012 and 2022 were retrospectively analyzed. Perinatal data, concomitant deformities and anomalies, maternal data, MMC repair surgery duration, concurrent surgeries, complications, and central nervous system (CNS) infection were evaluated. Outcome of 134 neonates with MMC is reported. Hydrocephalus was seen in 88 (65.7%), Chiari type II malformation in 84 (62.7%), orthopedic anomaly in 41 (30.6%), rib anomaly in 17 (12.7%), kyphosis in 26 (19.4%), and scoliosis in 5 (11.2%) neonates. 59 (44.0%) neonates underwent MMC surgery in < 48 h. Wound dehiscence/cerebrospinal fluid (CSF) discharge at the MMC repair site occurred in 5 (8.5%) neonates; only 2 (3.4%) had CNS infection. Late (> 48 h) repair was performed on 75 (55.9%) neonates. 6(8%) neonates experienced wound dehiscence/CSF discharge, and 8 (10.7%) developed CNS infection. Kyphectomy was performed on 9/26 (34.6%) neonates. Prognostic factors for kyphectomy included pregnancy number of MMC neonate (p = 0.049), postpartum MMC repair day (p = 0.027), number of previous operations (p < 0.001), presence and number of concurrent surgeries (p < 0.001 and p < 0.001, respectively), and history of Chiari II operation (p = 0.002). The prognosis for neonates with MMC is primarily determined by the effective surgical and medical management of associated deformities and conditions, such as kyphosis, hydrocephalus, and Chiari type II malformation, rather than the timing of MMC sac repair (early vs. delayed surgery). The decision-making process regarding the timing and technique of corrective surgeries should focus on the severity of symptoms related to Chiari II malformation and kyphosis in the neonate rather than their radiologic presence.

BACKGROUND:Recent studies suggest that large language models (LLMs) such as ChatGPT are useful tools for medical students or residents when preparing for examinations. These studies, especially those conducted with multiple-choice questions, emphasize that the level of knowledge and response consistency of the LLMs are generally acceptable; however, further optimization is needed in areas such as case discussion, interpretation, and language proficiency. Therefore, this study aimed to evaluate the performance of six distinct LLMs for Turkish and English neurosurgery multiple-choice questions and assess their accuracy and consistency in a specialized medical context. METHODS:A total of 599 multiple-choice questions drawn from Turkish Board examinations and an English neurosurgery question bank were presented to six LLMs (ChatGPT-o1pro, ChatGPT-4, AtlasGPT, Gemini, Copilot, and ChatGPT-3.5). Correctness rates were compared using the proportion z-test, and inter-model consistency was examined using Cohen's kappa. RESULTS:ChatGPT-o1pro, ChatGPT-4, and AtlasGPT demonstrated relatively high accuracy for Single Best Answer-Recall of Knowledge (SBA-R), Single Best Answer-Interpretative Application of Knowledge (SBA-I), and True/False question types; however, performance notably decreased for questions with images, with some models leaving many unanswered items. CONCLUSION:Our findings suggest that GPT-4-based models and AtlasGPT can handle specialized neurosurgery questions at a near-expert level for SBA-R, SBA-I, and True/False formats. Nevertheless, all models exhibit notable limitations in questions with images, indicating that these tools remain supplementary rather than definitive solutions for neurosurgical training and decision-making.

Background/Objectives: We aimed to review pediatric patients who underwent surgical treatment for posterior fossa tumors and to share our experience with the various types of dural grafts used in these patients. Methods: We carried out a retrospective study on pediatric patients who received surgical treatment for posterior fossa tumors and underwent duraplasty using either an autograft or a xenograft from January 2018 to December 2022. Data were gathered from patients’ medical records, encompassing demographic details. Additional information included tumor locations and the extent of resection. Factors such as postoperative complications like meningitis, pseudo-meningocele, and hydrocephalus were also noted. Results: Our cohort included 50 patients, 13 of whom underwent surgeries with autografts and 37 had xenografts. The patients’ tumors were in various areas, including intraventricular or those extending into the ventricle (31) and intracerebellar (17) and extra-axial (2) cases. Subtotal resection occurred in 8 cases, near-total resection in 9, and gross-total resection in 33. Postoperatively, meningitis occurred in 12 patients, pseudo-meningocele in 13, and hydrocephalus in 10, with 9 requiring V/P placement. Conclusions: In conclusion, techniques for dural closure hold great significance in neurosurgery, particularly during pediatric posterior fossa surgeries. Although the modest size of the autograft cohort limited statistical power, our epidural onlay fascia lata autograft produced fewer postoperative complications than the bovine xenograft and achieved outcomes comparable to those reported for watertight closure.

Background and Objectives: Unplanned return to the operating room (URTOR) is a sensitive indicator of surgical quality; however, data in neurosurgery are limited. This retrospective study analyzed patients who underwent URTOR following neurosurgical procedures over an eight-year period to define early and late patterns, identify underlying causes, and evaluate the distribution of cases according to surgeon experience. Materials and Methods: Records of 18,258 consecutive surgeries including both elective and emergency procedures in adult and pediatric patients, performed at a single center between 2010 and 2018 were retrospectively reviewed. Unplanned reoperations within 30 days of the index surgery were defined as URTOR; those occurring within ≤7 days were classified as “early,” and those occurring between 8 and 30 days were classified as “late.” Demographic data, surgical characteristics, causes of URTOR, and surgeons’ seniority were examined. Results: Among 18,258 neurosurgical procedures, 324 URTORs (1.8%) were identified. The median patient age was 38 years; 37% were children. Early URTOR comprised 59% and was primarily associated with hemorrhagic–vascular complications, whereas late URTOR accounted for 41% and was dominated by cerebrospinal fluid-related and infectious complications. Late events prevailed in significantly younger cases and were disproportionately followed by ventriculo–peritoneal shunt or endoscopic third ventriculostomy index operations. Junior surgeons performed 74% of later operations requiring URTOR versus 30% of early failures. Sex, weekday/weekend timing, and surgeons’ experience did not affect the overall URTOR classification categories. The median interval was six days. Conclusions: Centers worldwide have begun to examine URTOR rates, which are directly associated with hospital quality measurements. These results may inform targeted education and prevention by identifying patient groups at higher reoperation risk within a specific timeframe.

Spinal cord injury (SCI), which is characterized by motor and/or sensory dysfunction, presents a significant health challenge resulting from mechanical trauma. Secondary injury, which follows the mechanical trauma and is driven by factors such as inflammation, plays a critical role in the SCI pathophysiology. Scientific evidence indicates that treatment strategies aimed at modulating inflammation during the acute phase of SCI alleviate the seconder injury. In this regard, the present study seeks to evaluate the effectiveness of certolizumab, a monoclonal antibody targeting TNF-α that is widely used in the treatment of various inflammatory diseases, in a SCI model. In this study, Control, Trauma, and Trauma + Certolizumab groups were established, each comprising eight male rats. One hour after SCI induction, rats in the Trauma + Certolizumab group were administered 10 µg Certolizumab dissolved in saline intraperitoneally, while rats in the Control and Trauma groups received an equivalent volume of saline. After Modified Tarlov Scoring was performed on the seventh day of the experiment, all rats were sacrificed. The effects of certolizumab on neuroinflammation and apoptosis in the SCI model were evaluated using histological, biochemical, and molecular analyses of blood and tissue samples obtained from the rats. Certolizumab downregulated the expression of TNF-α, NF-κB, and IL-6. In addition, as evidenced by the TUNEL assay, Caspase-3 expression (an apoptotic marker), and Modified Tarlov Score results, certolizumab effectively suppressed inflammation-induced neural apoptosis and alleviated locomotor deficits. Certolizumab treatment exerts a neuroprotective effect against secondary damage in SCI through the inhibition of neuroinflammation and apoptosis.

In this study, 46 patients who were operated on for Type I Chiari malformation (CM) in our clinic since 2010 were included. The preoperative and postoperative cranial and spinal MRI examinations of all patients were compared between the two groups in terms of hydrocephalus, tonsillar herniation level, the presence and level of syringomyelia, osseous anomalies, postoperative cisterna magna formation, postoperative obex structure, and syringomyelia status.

BACKGROUND:Spinal cord injury is a devastating trauma that leaves survivors at risk for several medical complications throughout their lives. Lercanidipine, a third-generation calcium channel blocker, possesses anti-apoptotic, anti-inflammatory, and antioxidative properties. This study aimed to evaluate the neuroprotective effects of lercanidipine in an experimental spinal cord trauma model.METHODS:Twenty-one Wistar rats were randomly assigned to three groups. Group 1 (G1) underwent laminectomy. Group 2 (G2) were subjected to trauma following laminectomy. Group 3 (G3) were exposed to trauma following laminectomy and treated with lercanidipine. Lercanidipine was administered intraperitoneally for seven days. Histopathological and immunohistochemical evaluations were conducted.RESULTS:Regarding Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, there was no significant difference among the groups. However, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) levels were significantly different across the groups. G2 had significantly higher NF-κB levels compared to G1 and G3.CONCLUSION:Lercanidipine, a third-generation calcium channel blocker, is effective against inflammatory responses induced in spinal cord injury. Further studies are required to determine its capability in preventing apoptosis or improving functional recovery. To the best of our knowledge, this study is the first in the literature to examine the neuroprotective effects of lercanidipine on spinal cord injury.

Background/Objectives: This study aimed to investigate the surgical treatment and management of hydrocephalus in infants with meningomyelocele and compare the single-center experience with the previous studies. Methods: This retrospective study included 81 infants (47 females and 34 males) who underwent meningomyelocele closure surgery and subsequent ventriculoperitoneal (VP) shunt surgery for hydrocephalus. Clinical and demographic data were retrospectively collected from hospital records, focusing on variables such as the timing of VP shunt placement relative to MMC closure, postoperative complications, and the need for shunt revisions. Patients were followed for a mean duration of 58.11 months to monitor long-term outcomes and identify factors associated with shunt failures and infections. Results: The mean follow-up period since birth was 58.11 (33.72) months. Shunt problems affected 30% (25/81) of patients with mechanical causes (8/25) and infections (6/25). A proximal mechanical malfunction/dysfunction was seen in 32% (8/25) of the shunts. Shunt infections occurred in 23% (19/81) of infants, and the mean time for shunt infection onset following the VP shunt procedure was 0 (0-39) median (min-max) months. Overall, 8 (9.9%) infants had short-term shunt infections, whereas 11 (13.6%) had long-term shunt infections. The mean length of the intensive care unit stay was 35.75 (25.28) days. Significant difference was seen in the number of shunt reoperations for short- and long-term infections (p < 0.001). All infants had at least one operation before the infection of their shunt system. Male gender was significantly associated with long-term shunt infections (p = 0.021). The study revealed methicillin-resistant coagulase-negative staphylococcus to be the most common isolated organism from infected shunts at 72.7% (6/11). Conclusions: This study demonstrates that hydrocephalic infants with meningomyelocele undergoing VP shunt surgery face notable risks of infection and mechanical complications, with methicillin-resistant coagulase-negative staphylococcus identified as the most common pathogen. The findings emphasize the importance of comprehensive postoperative care and targeted infection management to improve outcomes in this vulnerable population.

BACKGROUND AND OBJECTIVES:Surgical approaches to the ventral brainstem and petroclival regions are complex, and standard retrosigmoid and subtemporal approaches are often inadequate. Retrosigmoid suprameatal tubercle (RSMTA) and anterior subtemporal transpetrosal (ASTA) approaches may provide extended surgical exposure with less brain retraction. The objective of this study was to evaluate advantages and disadvantages of RSMTA vs ASTA, and illustrate the surgical corridors and 3-dimensional microsurgical anatomy of the related structures.METHODS:Four silicone-injected adult cadaver heads (8 sides) were dissected to evaluate the accessibility of lesions located at the petrous apex, ventral brainstem, and pontomedullary region using ASTA and RSTMA.RESULTS:Both ASTA and RSMTA provide access from the petrous apex to the ventral lower pons and pontomedullary junction. A greater extent of safely resected bone was found in ASTA vs RSMTA. ASTA provides a larger surgical view to the ventrolateral midpons, peritrigeminal region, superior neurovascular complex, pontomesencephalic junction, and posterior cavernous sinus. Meanwhile, through cranial nerve V mobilization, RSMTA provides a larger surgical view to the lower half part of the pons, ventrolateral part of the pontomedullary junction, and middle and lower neurovascular structures.CONCLUSION:The choice of surgical approach is determined by considering the area where the lesion originates, lesion size, the anatomic structures to which it extends, and evaluation of the area that can be surgically exposed. Our study highlights the differences between these approaches and important surgical anatomic considerations.

Objective:The intraoperative diagnosis of neurosurgical biopsy material is usually tricky due to small size, artifacts of freezed neural tissue.When we are using rapid techniques, we should be aware of the limitations.In this study, we evaluate the diagnostic value of smears, frozen sections in neuropathology practice. Methods:We evaluated 65 neurosurgical biopsy materials sent for intraoperative diagnosis.All of them were interpreted with both smear and frozen section preparations.Results were grouped as inadequate (normal tissue, full of necrosis, technical artifacts), inflammatory/reactive or neoplastic.Difficulties, limitations of rapid methods were discussed. Results:Frozen and paraffine diagnoses were concordant in 55 cases.Three were inflammatory/reactive and fifty-two were tumor [low grade glial tumor (11), ependymoma (1), glioblastoma (12), metastasis (5), meningioma (8), craniopharyngioma (2), pituitary adenoma (2), epidermoid cyst (1), central neurocytoma (1), medulloblastoma (2), schwannoma/neurofibroma (6), diffuse large B cell lymphoma (1)].In two cases, the amount of the material was sufficient but we could not achieve a definitive diagnosis with squash and frozen sections.The paraffine result of these cases was giant cell ependymoma and vasculitis.In eight cases, the material was insufficient for diagnosis.The frozen material contained only necrosis in six cases [glioblastoma (4) and metastasis (2)]; normal parenchyma in a DNET case, cauterized tissue in a fibrous meningioma case. Conclusion:The accuracy of intraoperative diagnosis of neurosurgical material is very high.Also, the results of smear preparation and frozen section are concordant in most entities.The main role of rapid techniques in neuropathology is to determine whether the tissue is representative and adequate for ancillary testing such as immunohistochemistry and molecular.We should always be keep in touch with neurosurgeon and complemented morphological findings with radiological and clinical characteristics for the most reliable diagnostic interpretation.

ÖzObjective: One of the prognostic factors for glioblastoma (GBM) is isocitrate dehydrogenase (IDH) status.In addition, it has been stated that the neutrophil lymphocyte ratio (NLR) in GBM effects prognosis.In this study, we aimed to reveal the relationship between preoperative NLR and IDH status in GBM patients.Methods: Age, gender, preoperative NLR value, IDH status, Ki67 and p53%, and ATRX status of the patients were recorded in two groups: IDH mutant 7 patients and IDH wild type (IDH-Wt) 24 patients.Results: When the two groups were examined, no statistical difference was found between the loss of ATRX expression, Ki67 and p53 markers, and preoperative NLR values.Only IDH mutant patients were younger (p=0.037). Conclusion:Although it is seen that the pre-operative NLR value is not useful in determining the IDH status in GBM patients, it can be said that low NLR may have a positive effect on overall survival.

Objective: In recent years, the cavitron ultrasonic surgical aspirator has become an indispensable surgical tool for many neurosurgeons. The aim of the present study was to determine the relationship between the use of the cavitron ultrasonic surgical aspirator and the volume of the material obtained for pathological studies. Methods: The study was conducted with data from 80 consecutive patients undergoing surgical removal of a brain tumor between 2015 and 2019. Clinical records were analyzed retrospectively. Preoperative and postoperative tumor volume measurements were performed on magnetic resonance images using the Aquarius Intuition Client Viewer program available on our picture archiving and communication system. Excised tumor volumes were calculated. The effect of using the cavitron ultrasonic surgical aspirator on the amount of excised tissue, histopathological diagnosis, and excision time of the material sent to our pathology department for histopathological examination was calculated. Results: Mean age was 52.9 years. Preoperative tumor volumes and resected tumor volumes were significantly higher in group 1 (p=0.026; 0.03 respectively). Operation time spent per excised tumor volume was significantly shorter in group 1 (p=0.005). The amount of material sent to pathology was higher in group 2 (p=0.026). There were no complications related to the resection using the cavitron ultrasonic surgical aspirator and it was found to be useful for tumor removal. Conclusion: The cavitron ultrasonic surgical aspirator is a highly helpful tool for surgical intervention. This method based on aspiration may have some negative effects on pathological specimens if cavitron ultrasonic surgical aspirator aspirate material not transferred to the pathology department.

Objective Surgical access to the third ventricle can be achieved through various corridors depending on the location and extent of the lesion; however, traditional transcranial approaches risk damage to multiple critical neural structures. Methods Endonasal approach similar to corridor of the reverse third ventriculostomy (ERTV) was surgically simulated in eight cadaveric heads. Fiber dissections were additionally performed within the third ventricle along the endoscopic route. Additionally, we present a case of ERTV in a patient with craniopharyngioma extending into the third ventricle. Results The ERTV allowed adequate intraventricular visualization along the third ventricle. The extracranial step of the surgical corridor included a bony window in the sellar floor, tuberculum sella, and the lower part of the planum sphenoidale. ERTV provided an intraventricular surgical field along the foramen of Monro to expose an area bordered by the fornix anteriorly, thalamus laterally, anterior commissure anterior superiorly, posterior commissure, habenula and pineal gland posteriorly, and aqueduct of Sylvius centered posterior inferiorly. Conclusion The third ventricle can safely be accessed through ERTV either above or below the pituitary gland. ERTV provides a wide exposure of the third ventricle through the tuber cinereum and offers access to the anterior part as far as the anterior commissure and precommissural part of fornix and the whole length of the posterior part. Endoscopic ERTV may be a suitable alternative to transcranial approaches to access the third ventricle in selected patients.

Purpose Sellar metastases are rare lesions. Recent improvements in diagnosis and treatment strategies have prolonged survival but increased the probability of metastatic tumors. Evaluation with clinical symptomatology and meticulous laboratory examination is crucial. We present our multicenter national study on sellar metastases to evaluate and underline the main clinical, endocrine, and radiological considerations regarding the diagnosis and endonasal endoscopic management of such rare lesions. Methods A medical literature-based retrospective study was planned across 13 neurosurgical centers in Turkey, where a data survey was conducted to collect information regarding sellar metastases surgically treated using the endoscopic endonasal approach, including clinical presentation, radiographic features, primary tumor origin, histopathological confirmation, time to metastasis, treatment, and patient outcomes. Results Between 2010 and 2020, 54 patients (22 women [40.7%] and 32 men [59.3%]) who underwent surgery with the endonasal endoscopic approach and had pathologically proven sellar metastases (overall incidence, 0.54%) were included. Of the patients, 59.3% had no known malignancy and presented with new-onset symptoms, 79.6% reported headache, 51.9% complained of some degree of visual deficits, and 50% had cranial nerve symptoms. Tissue biopsy was performed in 7.4% of the patients, whereas gross or subtotal resection was achieved in the remaining patients. Conclusion To our knowledge, this is the largest series of patients surgically treated with the endonasal endoscopic approach for sellar metastases. For these patients, the treatment focus should be on management modalities for increasing quality of life instead radical treatment options with survival benefit.

BACKGROUND:Central nervous system infection after neurosurgical procedures is a severe complication with high morbidity rates and sometimes mortality. Our experimental study aimed to investigate the biochemical and histopathologic effects of vancomycin on neural tissues when applied to the cisterna magna.METHODS:Wistar albino rats were randomly divided into 4 groups: Control (Group 1) and different vancomycin dose groups (Groups 2, 3, and 4). In Group 1, 0.1 mL cerebrospinal fluid was drained from the cisterna magna and 0.1 mL 0.9% NaCI (normal saline) was administered into the subarachnoid space. In the study groups, 0.1 mL cerebrospinal fluid was drained from the cisterna magna and 0.1 mg/200g rat per day (Group 2), 0.2 mg/200g rat per day (Group 3), and 0.4 mg/200g rat per day (Group 4) vancomycin were administered into the subarachnoid space for 7 days. All rats were sacrificed on the eighth day. Serum superoxide dismutase and catalase levels were measured. Histopathologic and immunohistochemical analyses were conducted.RESULTS:The findings showed that the administration of 0.2 and 0.4 mg/kg doses had significant differences in superoxide dismutase and catalase activity compared with the controls (P < 0.05). These vancomycin doses also induced the apoptotic process, and the enzyme activity results correlated with immunohistochemical results.CONCLUSIONS:Dose-related neurotoxicity of intrathecal vancomycin was shown at the cellular level. The importance of dose regulation of intrathecal vancomycin has come into view. To our knowledge, this is the first study in the literature that has investigated the neurotoxic effects of vancomycin.

Objective: Anatomic variations of the vertebrobasilar junction have been described as uncommon, but may have important neurosurgical implications. The aim of this study is to emphasize the importance of the variations during the surgery and report the frequency of detected uncommon variations through cadaver dissection and computed tomography angiography. Methods: A combined cadaveric and radiologic study was performed to assess for basilar artery fenestration, intervertebral transversal anastomosis, and persistent primitive lateral vertebrobasilar anastomosis. Thirteen formalin-fixed human cadaveric heads were perfused with red- and blue-colored silicone and dissected in a stepwise manner through an endoscopic endonasal transclival approach. Radiologic data from 887 subjects were retrospectively analyzed for the presence of intervertebral transversal anastomosis. Results: Basilar artery fenestration was found in 7 patients (0.8%), intervertebral transversal anastomosis in 1 (0.1%), and persistent primitive lateral vertebrobasilar anastomosis in 1 (0.1%) by CTA analysis. Conclusion: Anatomic variations of the vertebrobasilar junction are a rare, but important, finding in vascular neurosurgery practice. We also report the first case of intervertebral transversal anastomosis discovered through human brain dissection. Cite this article as: Karadağ A, Şenoğlu M, Turkis ÖF, et al. Microsurgical perspective for uncommon variations associated with the vertebrobasilar junction: An anatomical and radiologic investigation. Cerrahpaşa Med J. 2022;46(2):97-100.

Objectives: The purpose of this study is to find out the accuracy of bilateral cavernous sinus sampling (CSS) for preoperative tumor lateralization within the pituitary in Cushing’s disease (CD). Methods: Sixty-five patients who had undergone transsphenoidal surgery (TSS) following CSS for CD between 2000-2016 at our institution were analyzed retrospectively. All patients underwent bilaterally CSS with corticotropin-releasing hormone (CRH) stimulation. Radiological, preoperative, and pathological findings with remission status were correlated with CSS data. The accuracy of CSS is decided according to compliance with the magnetic resonance imaging (MRI), pathology or remission after surgery of the normal MRI cases. Results: CSS indicated the correct lateralization in 52 (80%) patients. There was the same level elevation of both sides in 3 patients who had central adenoma. Remission rate in the final follow-up was 83.87% for 65 patients. We found out the contralateral pathological side in 13 (20%) of the patients showing false lateralization. Twenty-four patients with normal MRI had a positive accuracy rate of 83%. Of those patients, with a positive accuracy of CSS sampling, 18 (90%) had a positive remission. As a result of the Kappa analysis, statistically significance and relation was found between the final diagnosis and lateralization test (κ=0,63 p < 0.001). Conclusions: Our results showed that CSS is a safe and reliable method for microadenomas which has high diagnostic accuracy (80%) in indicating the correct lateralization in CD, providing us higher remission rates in a challenging pathology.