Comparison of MRI findings of hypothalamic-optic chiasmatic gliomas and craniopharyngiomas.

BACKGROUND: Differential diagnosis of hypothalamic-optic chiasmatic gliomas (HOCGs) and craniopharyngiomas on magnetic resonance imaging (MRI) can be quite challenging. PURPOSE: To compare the MRI features of HOCGs and cranipharyngiomas. MATERIAL AND METHODS: Patients diagnosed with HOCG or craniopharyngioma in histopathological evaluation between 2012 and 2022 and who underwent preoperative contrast-enhanced brain MRI were included. Various MRI features were retrospectively evaluated for each lesion: T2-weighted imaging and fluid attenuation inversion recovery hyperintensity, calcification, cystic change, T1-weighted (T1W) imaging hyperintensity of the cystic component, hemorrhage, involvement of sellar, suprasellar or other adjacent structures, lobulated appearance, presence of hydrocephalus, and contrast enhancement pattern. Apparent diffusion coefficient (ADC) values were also evaluated and compared. RESULTS: Among 38 patients included, 13 (34%) had HOCG and 25 (66%) had craniopharyngioma. Craniopharyngiomas had a significantly higher rate of cystic changes, calcification, and T1W imaging hyperintensity of the cystic component than HOCGs (P <0.05). Of HOCGs, 92% had chiasm involvement, 23% had optic nerve involvement, and 31% had brain stem involvement. On the other hand, chiasm involvement was observed in 8% of craniopharyngiomas, but none had optic nerve and/or brain stem involvement (P <0.05). While 62% (8/13) of HOCGs had diffuse homogeneous enhancement, 80% (20/25) of craniopharyngiomas had a diffuse heterogeneous enhancement pattern. Mean ADC values were significantly higher in craniopharyngiomas compared to HOCGs (2.1 vs. 1.6 ×10-3mm2/s, P <0.05). CONCLUSION: Although some neuroimaging findings may overlap, features such as presence of cyst and calcification, brain stem and optic pathway involvement, different enhancement patterns, and ADC values may be helpful in the differential diagnosis of HOCGs and craniopharyngiomas.

Endoscopic trans-eustachian tube approach: identifying the precise landmarks, a novel radiological and anatomical evaluation.

PURPOSE: The endoscopic trans-eustachian approach (ETETA) is a less invasive approach to the infratemporal fossa (ITF), providing superior exposure compared to traditional transcranial approaches. The anatomy of the pharyngotympanic (eustachian) tube and adjacent neurovascular structures is complex and requires in-depth knowledge to safely perform this approach. We present a cadaveric and radiological assessment of critical anatomic considerations for ETETA. METHODS: Six adult cadaveric heads were dissected alongside examination of 50 paranasal sinus CT scans. Key anatomic relationships of the pharyngotympanic tube and adjacent structures were qualitatively and quantitatively evaluated. Descriptive statistics were performed for quantitative data. RESULTS: Anatomical and radiological measurements showed lateralization of the pharyngotympanic tube allows access to the ITF. The pharyngotympanic tube has bony and cartilaginous parts with the junction formed by the sphenoid spine and foramen spinosum. The bony part and tendon of the tensor tympani muscle were located at the posterior genu of the internal carotid artery. The anterior and inferior wall of the carotid canal was located between the horizontal segment of the internal carotid artery and petrous segment of the cartilaginous pharyngotympanic tube. CONCLUSION: The combination of preoperative radiographic assessment and anatomical correlation demonstrates a safe and effective approach to ETETA, which allowed satisfactory visualization of ITF. The morphological evaluation showed that the lateralization of the pharyngotympanic tube and related structures allowed a surgical corridor to reach the ITF. Endoscopic surgery through the pharyngotympanic tube is challenging, and in-depth understanding of the key anatomic relationships is critical for performing this approach.

Changing presentation of acromegaly in half a century: a single-center experience.

OBJECTIVE: Investigate the changes in the characteristics of presentation, in patients with acromegaly over a period of approximately half a century. METHODS: The medical records of patients diagnosed with acromegaly between 1980 and 2023 were retrospectively reviewed. The collected data were examined to assess any changes observed over the years and a comparison was made between the characteristics of patients diagnosed in the last decade and those diagnosed in previous years. RESULTS: A total of 570 patients were included in the study, 210 (37%) patients were diagnosed in the last decade. Patients diagnosed before 2014 had longer symptom duration before diagnosis, advanced age, larger pituitary adenomas, higher incidence of cavernous sinus invasion, and higher GH and IGF-1 levels than those diagnosed last decade (p < 0.05, for all). Furthermore, the patients diagnosed before 2014 had a lower rate of surgical remission (p < 0.001), and a higher prevalence of comorbidities such as diabetes, hypertension, colon polyps, and thyroid cancer at the time of diagnosis (p < 0.05, for all). CONCLUSION: There may be a trend for earlier detection of patients with acromegaly.

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.

Machine learning as a clinical decision support tool for patients with acromegaly.

OBJECTIVE: To develop machine learning (ML) models that predict postoperative remission, remission at last visit, and resistance to somatostatin receptor ligands (SRL) in patients with acromegaly and to determine the clinical features associated with the prognosis. METHODS: We studied outcomes using the area under the receiver operating characteristics (AUROC) values, which were reported as the performance metric. To determine the importance of each feature and easy interpretation, Shapley Additive explanations (SHAP) values, which help explain the outputs of ML models, are used. RESULTS: One-hundred fifty-two patients with acromegaly were included in the final analysis. The mean AUROC values resulting from 100 independent replications were 0.728 for postoperative 3 months remission status classification, 0.879 for remission at last visit classification, and 0.753 for SRL resistance status classification. Extreme gradient boosting model demonstrated that preoperative growth hormone (GH) level, age at operation, and preoperative tumor size were the most important predictors for early remission; resistance to SRL and preoperative tumor size represented the most important predictors of remission at last visit, and postoperative 3-month insulin-like growth factor 1 (IGF1) and GH levels (random and nadir) together with the sparsely granulated somatotroph adenoma subtype served as the most important predictors of SRL resistance. CONCLUSIONS: ML models may serve as valuable tools in the prediction of remission and SRL resistance.

Microsurgical anatomy and surgical exposure of the cerebellar peduncles.

A better understanding of the surgical anatomy of the cerebellar peduncles in different surgical approaches and their relationship with other neural structures are delineated through cadaveric dissections. We aimed to revisit the surgical anatomy of the cerebellar peduncles to describe their courses along the brain stem and the cerebellum and revise their segmental classification in surgical areas exposed through different approaches. Stepwise fiber microdissection was performed along the cerebellar tentorial and suboccipital surfaces. Multiple surgical approaches in each of the cerebellar peduncles were compared in eight silicone-injected cadaveric whole heads to evaluate the peduncular exposure areas. From a neurosurgical point of view, the middle cerebellar peduncle (MCP) was divided into a proximal cisternal and a distal intracerebellar segments; the inferior cerebellar peduncle (ICP) into a ventricular segment followed by a posterior curve and a subsequent intracerebellar segment; the superior cerebellar peduncle (SCP) into an initial congregated, an intermediate intraventricular, and a distal intramesencephalic segment. Retrosigmoid and anterior petrosectomy approaches exposed the junction of the MCP segments; telovelar, supratonsillar, and lateral ICP approaches each reached different segments of ICP; paramedian supracerebellar infratentorial, suboccipital transtentorial, and combined posterior transpetrosal approaches displayed the predecussation SCP within the cerbellomesencephalic fissure, whereas the telovelar approach revealed the intraventricular SCP within the superolateral recess of the fourth ventricle. Better understanding of the microsurgical anatomy of the cerebellar peduncles in various surgical approaches and their exposure limits constitute the most critical aspect for the prevention of surgical morbidity during surgery in and around the pons and the upper medulla. Our findings help in evaluating radiological data and planning an operative procedure for cerebellar peduncles.

Cervical Oblique Corpectomy: Revitalizing the Underused Surgical Approach With Step-By-Step Simulation in Cadavers.

ABSTRACT: Recently, the World Federation of Neurosurgical Societies Spine committee recommended that additional research on cost-benefit analysis of various surgical approaches for cervical spondylotic myelopathy be carried out and their efficacy with long-term outcomes be compared. Unfortunately, it is highly probable that the oblique corpectomy (OC) will not be included in cost-benefit investigations due to its infrequent application by neurosurgeons dealing with the spine. In this cadaveric study, head and necks of 5 adult human cadavers stained with colored latex and preserved in 70% alcohol solution were dissected under a table-mounted surgical microscope using 3× to 40× magnifications. The OC approach was performed to simulate real surgery, and the neurovascular structures encountered during the procedure and their relations with each other were examined. Oblique corpectomy was performed unilaterally, although neck dissections were performed bilaterally on 10 sides in all 5 cadavers. At each stage of the dissection, multiple three-dimensional photographs were obtained from different angles and distances. For an optimal OC, both the anterior spinal cord must be sufficiently decompressed and sufficient bone must be left in place to prevent instability in the cervical spine. Oblique corpectomy is a valid and potentially low cost alternative to other anterior and posterior approaches in the surgical treatment of cervical spondylotic myelopathy. However, meticulous cadaver studies are essential before starting real surgical practice on patients in order to perform it effectively and to avoid the risks of the technique.

Microsurgical endoscopy-assisted presigmoid retrolabyrinthine approach with mastoid bone drilling: an anatomical laboratory investigation.

PURPOSE: This study aims to evaluate the applicability of the endoscopy-assisted presigmoid retrolabyrinthine approach, advantages, disadvantages, and the applicability of surgery with pre-op radiological parameters; identify important landmarks; and to reveal their relationships with important structures in the surgical field with objective data. Also, we aim to improve the surgical technique for increasing reachable anatomic structure. METHODS: Mastoid drilling and endoscopy-assisted presigmoid retrolabyrinthine approach were performed and endoscopic instruments were used to obtain the three-dimensional pictures. Computed tomography images were evaluated to correlate to the anatomic data. RESULTS: In terms of pre-operative radiological evaluation of the applicability of the presigmoid approach were investigated with selected radiological parameters. The endoscopy-assisted presigmoid retrolabyrinthine approach applied to cadavers the relationship, distances between important anatomical landmarks, and anatomical structures in the surgical field recorded. The anatomical structures that could reach with the application of the procedure were recorded. The relationship between pre-operative measured radiological parameters and surgical results was evaluated with objective data. Additional combinations to improve this surgical method discussed and the results of our combination were recorded with photographs. CONCLUSION: Although the presigmoid retrolabyrinthine approach has facilitated with the assistance of endoscope, it has observed that there are still some difficulties, and it has been concluded that the radiological parameters are useful in evaluating the applicability of this surgery. It observed that this surgery can be performed more effectively with combinations.

The benefits of inferolateral transtubercular route on intradural surgical exposure using the endoscopic endonasal transclival approach.

BACKGROUND: Surgical access to the ventral pontomedullary junction (PMJ) can be achieved through various corridors depending on the location and extension of the lesion. The jugular tubercle (JT), a surgically challenging obstacle to access the PMJ, typically needs to be addressed in transcranial exposures. We describe the endoscopic endonasal transclival approach (EETCA) and its inferolateral transtubercular extension to assess the intradural surgical field gained through JT removal. We also complement the dissections with an illustrative case. METHODS: EETCA was surgically simulated, and the anatomical landmarks were assessed in eight cadaveric heads. Microsurgical dissections were additionally performed along the endoscopic surgical path. Lastly, we present an intraoperative video of the trans-JT approach in a patient with lower clival chordoma. RESULTS: The EETCA allowed adequate extracranial visualization and removal of the JT. The surgical bony window-obtained along the clivus and centered at the JT via the EETCA-measured 11 × 9 × 7 mm. Removal of the JT provided an improved intradural field within the lower third of the cerebellopontine cistern to expose an area bordered by the cranial nerves VII/VIII and flocculus superior and anterior margin of the lateral recess of the fourth ventricle and cranial nerves IX-XI inferiorly, centered on the foramen of Luschka. CONCLUSIONS: Removal of the JT via EETCA improves exposure along the lower third of the cerebellopontine and upper cerebellomedullary cisterns. The inferolateral transtubercular extension of the EETCA provides access to the lateral recess of the fourth ventricle, in combination with the ventral midline pontomedullary region.

Chondrosarcoma in the body of the C2 vertebral axis.

Chondrosarcoma, a malignant bone tumor, is rarely encountered in the cervical spine. This article describes a patient whose neck pain and dysphagia were caused by an expansive, destructive lesion with calcification that was located in the body of the axis (C2 vertebra), the first time a chondrosarcoma has been reported in this location.

Predicting response to somatostatin analogues in acromegaly: machine learning-based high-dimensional quantitative texture analysis on T2-weighted MRI.

OBJECTIVE: To investigate the value of machine learning (ML)-based high-dimensional quantitative texture analysis (qTA) on T2-weighted magnetic resonance imaging (MRI) in predicting response to somatostatin analogues (SA) in acromegaly patients with growth hormone (GH)-secreting pituitary macroadenoma, and to compare the qTA with quantitative and qualitative T2-weighted relative signal intensity (rSI) and immunohistochemical evaluation. METHODS: Forty-seven patients (24 responsive; 23 resistant patients to SA) were eligible for this retrospective study. Coronal T2-weighted images were used for qTA and rSI evaluation. The immunohistochemical evaluation was based on the granulation pattern of the adenomas. Dimension reduction was carried out by reproducibility analysis and wrapper-based algorithm. ML classifiers were k-nearest neighbours (k-NN) and C4.5 algorithm. The reference standard was the biochemical response status. Predictive performance of qTA was compared with those of the quantitative and qualitative rSI and immunohistochemical evaluation. RESULTS: Five hundred thirty-five out of 828 texture features had excellent reproducibility. For the qTA, k-NN correctly classified 85.1% of the macroadenomas regarding response to SAs with an area under the receiver operating characteristic curve (AUC-ROC) of 0.847. The accuracy and AUC-ROC ranges of the other methods were 57.4-70.2% and 0.575-0.704, respectively. Differences in predictive performance between qTA-based classification and the other methods were significant (p < 0.05). CONCLUSIONS: The ML-based qTA of T2-weighted MRI is a potential non-invasive tool in predicting response to SAs in patients with acromegaly and GH-secreting pituitary macroadenoma. The method performed better than the qualitative and quantitative rSI and immunohistochemical evaluation. KEY POINTS: • Machine learning-based texture analysis of T2-weighted MRI can correctly classify response to somatostatin analogues in more than four fifths of the patients. • Machine learning-based texture analysis performs better than qualitative and quantitative evaluation of relative T2 signal intensity and immunohistochemical evaluation. • About one third of the texture features may not be excellently reproducible, indicating that a reliability analysis is necessary before model development.

Preoperative evaluation of tumour consistency in pituitary macroadenomas: a machine learning-based histogram analysis on conventional T2-weighted MRI.

PURPOSE: To evaluate the potential value of machine learning (ML)-based histogram analysis (or first-order texture analysis) on T2-weighted magnetic resonance imaging (MRI) for predicting consistency of pituitary macroadenomas (PMA) and to compare it with that of signal intensity ratio (SIR) evaluation. METHODS: Fifty-five patients with 13 hard and 42 soft PMAs were included in this retrospective study. Histogram features were extracted from coronal T2-weighted original, filtered and transformed MRI images by manual segmentation. To achieve balanced classes (38 hard vs 42 soft), multiple samples were obtained from different slices of the PMAs with hard consistency. Dimension reduction was done with reproducibility analysis, collinearity analysis and feature selection. ML classifier was artificial neural network (ANN). Reference standard for the classifications was based on surgical and histopathological findings. Predictive performance of histogram analysis was compared with that of SIR evaluation. The main metric for comparisons was the area under the receiver operating characteristic curve (AUC). RESULTS: Only 137 of 162 features had excellent reproducibility. Collinearity analysis yielded 20 features. Feature selection algorithm provided six texture features. For histogram analysis, the ANN correctly classified 72.5% of the PMAs regarding consistency with an AUC value of 0.710. For SIR evaluation, accuracy and AUC values were 74.5% and 0.551, respectively. Considering AUC values, ML-based histogram analysis performed better than SIR evaluation (z = 2.312, p = 0.021). CONCLUSION: ML-based T2-weighted MRI histogram analysis might be a useful technique in predicting the consistency of PMAs, with a better predictive performance than that of SIR evaluation.

The effects of pre-operative somatostatin analogue therapy on treatment cost and remission in acromegaly.

PURPOSE: To investigate the effects of preoperative somatostatin analogue (SSA) treatment on the annual cost of all acromegaly treatment modalities and on remission rates. METHODS: The medical records of 135 patients with acromegaly who were followed at endocrinology clinic of Cerrahpasa Medical Faculty for at least 2 years after surgery between 2009 and 2016 were reviewed. RESULTS: The mean follow-up time was 50.9 ± 25.7 months. Early remission was defined according to 3rd month values in patients who didn't achieve remission, and 6th month values in patients who achieved remission at the 3rd month after surgery. The early and late remission rates of the entire study population were 40% and 80.7%, respectively. The early remission of the preoperative SSA-treated group (61.5%) was significantly higher than SSA-untreated group (31.2%) (p = 0.002). The early remission of the preoperative SSA-treated patients with macroadenomas (52.2%) was also significantly higher than the SSA-untreated group (23.5%) (p = 0.02). In the subgroup analysis; this difference was much more pronounced in invasive macroadenomas (p = 0.002). There were no differences between the groups in terms of late remission.The median annual cost of all acromegaly treatment modalities in study population was €3788.4; the cost for macroadenomas was significantly higher than for microadenomas (€4125.0 vs. €3226.5, respectively; p = 0.03). Preoperative SSA use in both microadenomas and macroadenomas didn't alter the cost of treatment. The increase in the duration of preoperative medical treatment had no effect on early or late remissions (p = 0.09; p = 0.8). CONCLUSIONS: Preoperative medical treatment had no effect on the costs of acromegaly treatment. There was a benefical effect of pre-operative SSA use on early remission in patients with macroadenomas; however, this effect didn't persist long term.

Transsphenoidal surgery for pituitary adenomas in pediatric patients: a multicentric retrospective study.

INTRODUCTION: Pediatric pituitary adenomas are rare lesions. Incidence is reported between 1 and 10% of all childhood brain tumors and between 3 and 6% of all surgically treated adenomas. Although pituitary adenomas present with symptoms of hormone hypersecretion or neurological disruptions secondary to mass effect, they are almost constantly benign. Characteristics of patients may vary in different studies according to age, gender, size of adenoma, hormonal activity, and recurrence rates. METHODS: Data on consecutive pediatric patients who were operated for pituitary adenoma with endoscopic endonasal transsphenoidal surgery (EETS) and transsphenoidal microsurgery (TMS) in the Department of Neurosurgery, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey, in the Neurosurgical Unit of the San Matteo Hospital, Pavia, Italy, and in the Division of Neurological Surgery Department of Biotechnology and Life Sciences, University of Insubria-Varese, ASST Sette Laghi, Ospedale di Circolo e Fondazione Macchi, Varese, Italy, between July 1997 and May 2018, were analyzed. Twenty-seven patients (11 males and 16 females), who were 18 years old or younger at the time of surgery, were included in the study. Medical records, images, and operative notes of patients were retrospectively reviewed. RESULTS: There were 16 females (59.3%) and 11 males (40.7%). Mean age was 15.3 ± 3.3 (4-18). Thirty-two surgical procedures were performed for 27 patients (6 children required second operation). Thirteen patients (48.14%) had Cushing's disease (CD), 5 patients (18.5%) had growth hormone (GH)-secreting adenoma, 5 patients (18.5%) had prolactinoma, and 4 patients (14.8%) had non-functional adenoma. Twenty-two patients (81.4%) met remission criteria, and 5 patients (18.5%) did not meet remission criteria. Four patients met remission criteria after the second operation. CONCLUSION: Transsphenoidal approach affords effective release of mass effect and not only restoration but also perpetuation of normal endocrine functions in the majority of pediatric pituitary adenoma patients. Satisfactory results are reported with both EETS and TMS in the literature. Despite the technical difficulties in pediatric age, transsphenoidal resection of adenoma is still the mainstay treatment that provides cure in pediatric patients.

Neurosurgical treatment of Cushing disease in pediatric patients: case series and review of literature.

AIM: Pituitary adenomas are rare in childhood in contrast with adults. Adrenocorticotropic hormone (ACTH)-secreting adenomas account for Cushing's disease (CD) which is the most common form of ACTH-dependent Cushing's syndrome (CS). Treatment strategies are generally based on data of adult CD patients, although some difficulties and differences exist in pediatric patients. The aim of this study is to share our experience of 10 children and adolescents with CD. PATIENTS AND METHOD: Medical records, images, and operative notes of 10 consecutive children and adolescents who underwent transsphenoidal surgery for CD between 1999 and 2014 in Cerrahpasa Faculty of Medicine were retrospectively reviewed. Mean age at operation was 14.8 ± 4.2 years (range 5-18). The mean length of symptoms was 24.2 months. The mean follow-up period was 11 years (range 4 to 19 years). RESULTS: Mean preoperative cortisol level was 23.435 µg/dl (range 8.81-59.8 µg/dl). Mean preoperative ACTH level was 57.358 µg/dl (range 28.9-139.9 µg/dl). MR images localized microadenoma in three patients (30%), macroadenoma in four patients (40%) in our series. Transsphenoidal microsurgery and endoscopic transsphenoidal surgery were performed in 8 and 2 patients respectively. Remission was provided in 8 patients (80%). Five patients (50%) met remission criteria after initial operations. Three patients (30%) underwent additional operations to meet remission criteria. CONCLUSION: Transsphenoidal surgery remains the mainstay therapy for CD in pediatric patients as well as adults. It is an effective treatment option with low rate of complications. Both endoscopic and microscopic approaches provide safe access to sella and satisfactory surgical results.

Germline mutations of aryl hydrocarbon receptor-interacting protein (AIP) gene and somatostatin receptor 1-5 and AIP immunostaining in patients with sporadic acromegaly with poor versus good response to somatostatin analogues.

OBJECTIVE: To determine aryl hydrocarbon interacting protein (AIP) gene variations and AIP and somatostatin receptor (SSTR) 1-5 immunostaining in patients with apparently sporadic acromegaly with poor versus good response to somatostatin analogues (SRLs). METHODS: A total of 94 patients (66 with poor and 28 with good response to SRLs) were screened for the AIP gene variations using Sanger sequencing. Immunostaining was performed in 60 tumors. RESULTS: Several variations, albeit some with undetermined significance, were detected, especially in poor responder patients. The prevalence of AIP mutation was 2.1% in the whole group and 1.5% in patients with poor response to SRLs. AIP, SSTR2A, and SSTR2B immunostainings were decreased in patients with poor response (p < 0.05 for all), and other SSTRs did not differ between the groups (p > 0.05 for all). Patients with low AIP had decreased levels of SSTR2A and SSTR3 (p < 0.05 for all). AIP and SSTR2A immunostainings were positively correlated to the treatment response and age at diagnosis was negatively correlated (p < 0.05 for all). In poor responder patients with high SSTR2A immunostaining, SSTR2B immunostaining and preoperative tumor size were positively and negatively correlated, respectively, to SRL response (p < 0.05 for all). CONCLUSIONS: Lack of response to SRLs does not necessarily increase the risk of harboring AIP mutations. The finding of decreased AIP, SSTR2A, and SSTR2B immunostaining in patients with poor response to SRLs and decreased SSTR2A and SSTR3 level in those with low AIP immunostaining suggests a possible interaction between AIP and some SSTR subtypes that might alter SRL sensitivity.

Surgical Pitfalls in Carotid Endarterectomy: A New Step-By-Step Approach.

Carotid endarterectomy (CEA) is a surgical intervention that may prevent stroke in asymptomatic and symptomatic patients. Our aim was to examine the microsurgical anatomy of carotid artery and other related neurovascular structures to summarize the CEA that is currently applied in ideal conditions. The upper necks of 2 adult cadavers (4 sides) were dissected using ×3 to ×40 magnification. The common carotid artery, external carotid artery (ECA), and internal carotid artery were exposed and examined. The surgical steps of CEA were described using 3-D cadaveric photos and computed tomography angiographic pictures obtained with help of OsiriX imaging software program. Segregating certain neurovascular and muscular structures in the course of CEA significantly increased the exposure. The division of facial vein allowed for internal jugular vein to be mobilized more laterally and dividing the posterior belly of digastric muscle resulted in an additional dorsal exposure of almost 2 cm. Isolating the ansa cervicalis that pulls hypoglossal nerve inferiorly allowed hypoglossal nerve to be released safely medially. The locations of the ECA branches alter depending on their anatomical variations. The hypoglossal nerve, glossopharyngeal nerve, and accessory nerve pierce the fascia of the upper part of the carotid sheath and they are vulnerable to injury because of their distinct courses along the surgical route. Surgical exposure in CEA requires meticulous dissection and detailed knowledge of microsurgical anatomy of the neck region to avoid neurovascular injuries and to determine the necessary surgical maneuvers in cases with neurovascular variations.

Endoscopic Endonasal Transethmoidal Approach for the Management of a Traumatic Brain Abscess and Reconstruction of the Accompanying Anterior Skull Base Defect.

Skull base endoscopy in the treatment of brain abscesses has been rarely published. Moreover, endoscopic endonasal transethmoidal approach (EETA) for the treatment of brain abscess following a head trauma has been reported only in a few case reports. We report the management of a patient of intracerebral abscess and reconstruction of the accompanying anterior skull base defect through an EETA.Thirty-year-old male with a frontal lobe abscess due to a penetrating skull base trauma was operated via EETA. After drainage of the abscess, dural and bony defects were repaired to prevent any recurrence. Postoperative radiological imaging revealed prominent decrease in abscess size. The patient did not need any further surgical intervention, and antibiotherapy was adequate.EETA is safe and effective in the management of brain abscesses. Skull base endoscopy provides direct visualization of the abscess cavity through a minimal invasive route, facilitates wide exposure of surrounding neurovascular structures within the operative field, and enables concurrent closure of the skull base defect.

Endoscopic approach to a collision tumor of growth hormone-secreting adenoma and gangliocytoma in the pituitary gland.

The authors share their experience on a collision tumor of growth hormone (GH)-secreting adenoma and gangliocytoma in the pituitary gland, which was reported by few articles in the literature. Also, an intraoperative view of this tumor, operated via endoscopic endonasal transsphenoidal approach, is presented for the first time. A 39-year-old female patient was admitted with clinical manifestation of acromegaly present in a 2-year period. Laboratory investigations revealed high levels of GH and insulinlike growth factor 1. Sellar computed tomography scan and magnetic resonance imaging showed a sellar mass diagnosed as a pituitary adenoma. Based on clinical, biochemical, and radiologic evaluations, GH-secreting pituitary adenoma was diagnosed and operated by endoscopic endonasal transsphenoidal approach achieving total removal of the tumor. Histopathologic examination revealed a collision tumor of GH-secreting adenoma and gangliocytoma. Postoperative radiologic and biochemical investigations showed no residual tumor and total remission. The endoscopic endonasal transsphenoidal approach promotes a close intraoperative view of sellar pathologies. We believe that a detailed histopathologic workup is necessary to diagnose collision tumors, because even a close intraoperative view does not facilitate to differentiate these tumors from a regular pituitary adenoma.