Rarely Used Endoscopic Transnasal Transdiaphragmatic Technique in Patients with Suprasellar Extension: A Tertiary Center's Experience with Eleven Patient Cases

OBJECTIVE

As surgical techniques become less invasive, the use of endoscopy in brain surgery supports this trend. Numerous endoscopic surgical approaches have been defined, especially for skull base diseases. The current study summarizes our experience of using the rarely reported endoscopic transnasal transdiaphragmatic approach through the existing hole in the diaphragma sella to access lesions extending into the suprasellar region.

METHODS

Our surgical team performed 4876 endoscopic endonasal surgeries between August 1997 and December 2022 at the Department of Neurosurgery, Pituitary Research Center, Faculty of Medicine, Kocaeli University. The study retrospectively analyzed data from 11 patients who had undergone endoscopic transnasal transdiaphragmatic surgery since January 2020. Preoperative and postoperative magnetic resonance imaging, pituitary function examination, and clinical observation were carried out.

RESULTS

The mean age of the patients was 31.1 ± 10.7 years and the female/male ratio was 6:5. Pathologic subtypes observed included breast cancer metastasis (n = 1), adrenocorticotropic hormone-secreting adenoma (n = 4), growth hormone-secreting adenoma (n = 3), craniopharyngioma (n = 2), and Rathke cleft cyst (n = 1). The mean postoperative hospital stay was 4.7 ± 1.1 days and none of the patients showed cerebrospinal fluid leakage during this period.

CONCLUSIONS

The endoscopic transnasal transdiaphragmatic approach may be considered an alternative to the conventional extended endoscopic transnasal approach in patients with lesions extending into the suprasellar region. The main strength of this method is that it facilitates suprasellar region access through a small dural incision and bone defect in the base of the skull. As a result, it also reduces the risk of postoperative cerebrospinal fluid leakage and associated complications.

Surgical outcomes and follow-up results of 53 pediatric craniopharyngioma cases: a single-center study

OBJECTIVE

Craniopharyngiomas are locally invasive neoplasms, and they cause potential lifelong morbidity because of their tendency for local recurrence. Despite advancements in endoscopic techniques, gross-total resection (GTR) of tumors with invasion or adhesion to important surrounding anatomical structures is extremely difficult. The authors present a single-center study that evaluated the impact of the endoscopic endonasal approach (EEA) on the surgical outcomes of pediatric craniopharyngiomas, the factors affecting the resection rate, and recurrence.

METHODS

A total of 44 pediatric patients (age ≤ 18 years) who were treated via the EEA for craniopharyngioma from August 1997 to June 2022, as well as their 53 operations, were included in this study. The preoperative radiological configuration and surgical data of these cases were assessed. Also, preoperative and postoperative clinical (endocrinologic, neurological, and ophthalmological), hypothalamic, physical and social development, and neurocognitive assessment data were described.

RESULTS

In total, 37 cases (69.8%) had no history of operation beforehand. The most common symptoms at presentation were endocrine disturbances (98.1%), headache without vomiting (84.3%), and visual disturbance (51%). Cases were classified as infrasellar (1.9%), sellar (32.1%), sellar-suprasellar (52.8%), and suprasellar (13.2%) localization. GTR was achieved in 34/53 cases (64.1%). The rate of GTR was higher in infrasellar and sellar tumors compared with sellar-suprasellar and suprasellar tumors (p = 0.003), and preoperative hypothalamic involvement was associated with lower likelihood of GTR (p = 0.024). Moreover, with experience, the rate of GTR increased (p = 0.037). Postoperative complications, other than endocrine impairment, occurred in 10/53 cases (18.9%). The mean duration of follow-up was 53.57 months. At follow-up, 21/53 (39.6%) cases presented with tumor recurrence. The 5-year progression-free survival (PFS) rate was 48.5%. There was a statistically significant difference between the GTR and other-than-GTR groups in terms of PFS (p < 0.001). According to univariate analysis, smaller tumor (p = 0.017), infrasellar and sellar localization (p = 0.031), and GTR (p < 0.001) were significantly associated with decreased rate of recurrence. Also, there was a statistically significant association between the recurrence rate and adhesion strength of the tumor (p < 0.001).

CONCLUSIONS

This retrospective cohort study revealed surgical indications for EEA, as well as factors affecting the resection rate, recurrence, and quality of life during the follow-up period of the included cases. The authors believe that GTR should be the goal for craniopharyngioma treatment, but the authors' treatment approach was to provide a balance between radical surgery with maximum safety and adjuvant treatment for long-term disease control.

A Novel Fusion of Radiomics and Semantic Features: MRI-Based Machine Learning in Distinguishing Pituitary Cystic Adenomas from Rathke's Cleft Cysts

Objectives

To evaluate the performances of machine learning using semantic and radiomic features from magnetic resonance imaging data to distinguish cystic pituitary adenomas (CPA) from Rathke's cleft cysts (RCCs).

Materials and Methods

The study involved 65 patients diagnosed with either CPA or RCCs. Multiple observers independently assessed the semantic features of the tumors on the magnetic resonance images. Radiomics features were extracted from T2-weighted, T1-weighted, and T1-contrast-enhanced images. Machine learning models, including Support Vector Machines (SVM), Logistic Regression (LR), and Light Gradient Boosting (LGB), were then trained and validated using semantic features only and a combination of semantic and radiomic features. Statistical analyses were carried out to compare the performance of these various models.

Results

Machine learning models that combined semantic and radiomic features achieved higher levels of accuracy than models with semantic features only. Models with combined semantic and T2-weighted radiomics features achieved the highest test accuracies (93.8%, 92.3%, and 90.8% for LR, SVM, and LGB, respectively). The SVM model combined semantic features with T2-weighted radiomics features had statistically significantly better performance than semantic features only (p = 0.019).

Conclusion

Our study demonstrates the significant potential of machine learning for differentiating CPA from RCCs.

Retinal vascular and structural recovery analysis by optical coherence tomography angiography after endoscopic decompression in sellar/parasellar tumors

We assessed the potential retinal microcirculation alterations for postoperative visual recovery in sellar/paraseller tumor patients with Optical Coherence Tomography Angiography (OCT-A). Two hundred ten eyes with sellar/parasellar tumor for which preoperative and postoperative (3 months) MRI Scans, Visual Acuity Test, Optical Coherence Tomography (OCT), OCT-A and, Visual Field Test data were available, besides 92 healthy eyes were evaluated. In the preoperative phase, significant reductions were observed in retinal vascular densities in various regions, including the Superficial Retinal Capillary Plexus (SRCP) (whole: p < 0.001, fovea: p = 0.025, parafovea: p < 0.001), Deep Retinal Capillary Plexus (DRCP) (whole: p < 0.001, fovea: p = 0.003, parafovea: p < 0.001), Peripapillary Vascular Density (PVD) (whole: p = 0.045, peripapillary: p < 0.001, nasal: p < 0.001, inferior: p < 0.001, temporal: p < 0.001), and Retinal Nerve Fiber Layer (RNFL) (nasal: p = 0.024, inferior: p < 0.001, temporal: p < 0.001, superior: p < 0.001) compared to the healthy control group. After surgery, the postoperative data of patients without chiasmal distortion were compared to their preoperative data. In the postoperative evaluation, significant increases were observed in vascular densities in patients without chiasmal distortion in the SRCP (whole: p < 0.001, parafovea: p = 0.045), DRCP (whole: p = 0.007, fovea: p = 0.006, parafovea: p = 0.040), PVD (peripapillary: p = 0.010, inferior: p < 0.001, temporal: p < 0.001, superior: p < 0.001), and RNFL (nasal: p = 0.011, inferior: p = 0.034, temporal: p = 0.046, superior: p = 0.011). Furthermore, significant associations were observed in the ROC analysis between the postoperative Visual Field Mean Deviation (VFMD) and SRCP (whole AUC = 0.793, p < 0.001, cut-off = 51.45, parafovea AUC = 0.820, p < 0.001, cut-off = 53.95), DRCP (whole AUC = 0.818, p < 0.001, cut-off = 55.95, parafovea AUC = 0.820, p < 0.001, cut-off = 59.05), PVD (temporal AUC = 0.692, p < 0.001, cut-off = 55.10), and RNFL (whole AUC = 0.690, p = 0.001, cut-off = 119.5, inferior AUC = 0.712, p < 0.001, cut-off = 144.75). These findings indicate a potential role of pre and post-operative OCT-A measurements in the assessment of surgical timing and postoperative visual recovery in patients with or without optic chiasm distortion.

Outcomes of Endoscopic Transsphenoidal Approach for More Aggressive Pediatric Pituitary Adenomas: Early- and Late-Term Results from a Single Center Experience

OBJECTIVE

Pediatric pituitary adenomas are rare lesions and account for approximately 3% of all supratentorial tumors in children. There is a paucity of reports on endoscopic transsphenoidal surgery in children. The aim of this study was to assess the early/late outcomes of endoscopic pediatric pituitary adenoma surgery at a high-volume tertiary center, as well as to characterize the factors associated with aggressive growth, including the histopathological features.

METHODS

Between August 1997 and June 2022, a total of 3256 patients underwent endoscopic transsphenoidal surgery for pituitary adenoma at the Department of Neurosurgery and Pituitary Research Center of the Kocaeli University School of Medicine. Of these, 70 (2.1%) pediatric patients (25 males, 45 females) (age ≤18 years) with a pathological diagnosis of pituitary adenoma were retrospectively reviewed.

RESULTS

The mean age of patients was 15.5 ± 2.3 years. Among the hormone-secreting adenomas, 19 (34.5%) were adrenocorticotrophic hormone secreting, 13 (23.6%) were growth hormone secreting, 19 (34.5%) were prolactin secreting, and 4 (7.2%) were both growth hormone-prolactin secreting. Gross total resection was achieved in 93.3% of nonfunctional tumors. The early/late surgical remission rates for hormone-secreting adenomas were 61.5%/46.1% (mean follow-up: 63.7 ± 49.3 months) for acromegaly, 78.9%/68.4% (47.8 ± 51.0 months) for Cushing disease, 57.8%/31.5% (72.2 ± 59.5 months) for prolactinoma, and 25%/25% (35.2 ± 31.4 months) for growth hormone-prolactin-secreting adenomas. Five sparsely granulated corticotroph tumors, 5 sparsely granulated somatotroph tumors, and 11 densely granulated lactotroph tumors were classified as aggressive histopathological subtypes.

CONCLUSIONS

The unique characteristics of the pediatric population and the aggressiveness of the disease in this population pose considerable therapeutic challenges. To increase treatment success, current adjuvant therapies that are appropriate for the morphological and biological characteristics of the tumor are required in addition to surgical treatment.

Endonasal endoscopic approach for sellar metastatic pathologies: a national observation

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.

Endoscopically operated 15 ventral skull-base dermoid and epidermoid cysts: Outcomes of a case series and technical note

BACKGROUND

Epidermoid and dermoid tumors in the sellar region are rare. These cystic lesions are a surgical challenge, as the thin capsule adheres firmly to nearby structures. A case series of 15 patients is presented.

METHODS

The patients were operated on in our clinic between April 2009 and November 2021. The endoscopic transnasal approach (ETA) was used. Lesions were located in the ventral skull base. In addition, the literature was reviewed to compare clinical features and outcomes of ventral skull-base epidermoid/dermoid tumors operated on via ETA.

RESULTS

In our series, removal of cystic contents and tumor capsule (gross total resection: GTR) was achieved in 3 patients (20%). GTR was not possible for the others, because of adhesions to vital structures. Near total resection (NTR) was achieved in 11 patients (73.4%), and subtotal resection (STR) in 1 (6.6%). At a mean follow-up of 55±26.27 months, there were no cases of recurrence requiring surgery.

CONCLUSION

Our series demonstrates that ETA is suitable for resection of epidermoid and dermoid cysts in the ventral skull base. GTR cannot always be the absolute clinical aim, because of inherent risks. In patients with expected long-term survival, the aggressiveness of surgery should be weighed on an individual risk/benefit basis.

Endoscopic Transnasal Approach for Microprolactinomas with Experience of 105 Cases in a Single Center: Paradigmal Shift for Conventional Medical Therapy

OBJECTIVE

The classically recommended first-line therapy for microprolactinomas is medical therapy. In the presence of drug resistance and intolerance after the use of dopamine agonists or when the patients prefer surgery instead of medication, surgical treatment is considered as second-line treatment. The high hormonal remission and low complication rates after surgery for microprolactinomas suggest that the surgical outcome of endoscopic surgeries may be better than medical therapy in well-selected patients. This study reports a large series of patients with microprolactinoma treated by endoscopic transnasal approach and evaluates the efficiency of surgical treatment.

METHODS

Our study is a retrospective cohort analysis of patients with microprolactinoma operated on by an endoscopic transnasal approach between August 1997 and February 2022 by an experienced pituitary surgeon in a single tertiary center. Inclusion criteria for microprolactinoma were based on increased prolactin levels, microadenoma (<10 mm in diameter) on pituitary magnetic resonance imaging, and histopathologically verified lactotroph adenoma.

RESULTS

The mean follow-up was 74.90 months (range, 6-207). The postoperative day 1 remission rate was 85.7% and the long-term remission rate was 74.3%. The long-term remission rates of the patients in the preference group were significantly higher than those of the patients in the resistant or intolerance group (P = 0.002). Patients who used dopamine agonists for more than 3 years had a lower remission rate compared with patients who used dopamine agonists for a shorter period or who did not use it (P = 0.01). The surgical complication rate was 4.76%.

CONCLUSIONS

According to our findings, endoscopic transnasal surgery performed by an experienced neurosurgeon in well-selected patients with microprolactinoma can be offered with cure rates superior to medical therapy and may be an alternative first-line treatment option to dopamine agonists.

Investigation of Demyelination and Remyelination Processes of the Compressed Optic Chiasm: An Experimental Model

AIM

To demonstrated demyelination and remyelination of the optic nerve histologically by electron microscopy in an experimental model similar to the compression of pituitary adenomas on the optic chiasm.

MATERIAL AND METHODS

The rats were fixed to a stereotaxic device under deep anesthesia, and a balloon catheter was placed under the optic chiasm through a burr hole which was in front of the bregma in accordance with the brain atlas of rats. The animals were divided into five groups (n=8): control, mild compression demyelination, severe compression demyelination, mild compression remyelination, severe compression remyelination. The fine structures of the tissues obtained were evaluated using electron microscopy.

RESULTS

We found a significant difference in the severity of degeneration when comparing group 1 with group 5 (p < 0.001); there was no degeneration in group 1 rats and severe degeneration in all of the group 5 rats. Oligodendrocytes were found in all rats in group 1 and none of the rats in no group 2. The nuclei were preserved in the group 1 rats but damaged in all of the group 5 rats. There were no lymphocytes or erythrocytes in group 1 and all positives in group 5.

CONCLUSION

This technique, which induced degeneration without causing damage to the optic nerve with toxic or chemical agents, revealed Wallerian degeneration similar to tumoral compression. After compression relief, the optic nerve remyelination process can be better understood, particularly for sellar lesions. In our opinion, this model may guide future experiments to identify protocols to induce and accelerate remyelination.

The Endoscopic Endonasal Transsphenoidal Approach for Thyrotropin-Secreting Pituitary Adenomas: Single-Center Experience and Clinical Outcomes of 49 Patients

OBJECTIVE

To analyze surgical outcomes and tumor characteristics of 49 patients with thyrotropin-secreting pituitary adenoma, a rare functional pituitary adenoma subtype with challenging surgery, who underwent endoscopic endonasal transsphenoidal surgery.

METHODS

In this single-center study, clinical, radiological, surgical, and endocrinological data of 49 patients diagnosed with thyrotropin-secreting pituitary adenoma were retrospectively reviewed.

RESULTS

Mean tumor size was 21.12 mm (6 microadenomas, 41 macroadenomas, 2 giant adenomas). Cavernous sinus invasion was present in 12 (24.48%) patients. Tumor consistency was firm in 23 (46.93%) patients. Plurihormonal secretion characteristics were present in 9 patients (5 growth hormone + thyrotropin and 4 growth hormone + prolactin + thyrotropin). Mean follow-up duration was 51.73 months. Of the cases with firm tumors, 14 patients had a history of antithyroid drug use; there was no statistically significant correlation between the antithyroid medication and the firmness of the tumor. Gross total resection was achieved in 32 (65.30%) cases, near-total resection was achieved in 14 (28.57%) cases, and subtotal resection was achieved in 3 (6.12%) cases. The analysis showed that the negative effect of >2 cm tumor size and cavernous sinus invasion on resection rate was statistically significant (P < 0.001). Although early remission was achieved in 33 (67.34%) patients, 44 (89.79%) patients were in euthyroid state at >3 months' follow-up. Complications were 4 new-onset pituitary deficiencies, 3 cases of permanent diabetes insipidus, 1 thyrotoxic crisis, and 1 cerebrospinal fluid leak.

CONCLUSIONS

Endoscopic endonasal transsphenoidal surgery is the first-line treatment in thyrotropin-secreting pituitary adenoma and should be performed in a tertiary center. Gross total resection is the goal, and early diagnosis is essential for surgical success.

Endoscopic Endonasal Approach Limitations and Evolutions for Tuberculum Sellae Meningiomas: Data from Single-Center Experience of Sixty Patients

INTRODUCTION

New detailed scoring systems have been introduced for surgical technique selection. These are greatly helpful and detailed but complex classifications. Despite developments and advances in the endoscopic technique, there are still debates on which of the methods used in surgery in tuberculum sellae meningiomas. Limitations of approaches are not clearly defined.

MATERIALS AND METHODS

We reviewed the medical data, radiological images, and surgical videos of the patients with pathologically confirmed meningiomas originating from the tuberculum sellae and they were operated via endoscopic endonasal approach between August 1997 and December 2020. We used our endoscopic classification based on infrachiasmatic corridor. In this classification, tumors were divided into those within the infrachiasmatic corridor and proximity of the optic nerve, internal carotid artery, and anterior artery complex and those outside the infrachiasmatic corridor.

RESULTS

Gross total resection was achieved in 45/60 (75%) patients. We found that tumor consistency was statistically significant on resection rates. Simultaneously, tumor median diameters on the anteroposterior (≤21.15 mm), transverse (≤19.75 mm), and superoinferior (≤15 mm) axes were statistically significant on resection rates.

CONCLUSION

In summary, the most important factor in selecting the surgical technique is the tumor size. Infrachiasmatic corridor boundaries are the limitations of endoscopic approach. These limitations can change based on surgeon's experience. Also, tumor consistency is a factor that affecting degree of tumor resection rates.

Outcome in pituitary apoplexy patients, stratified by delay between symptom appearance and surgery: A single center retrospective analysis

BACKGROUND

There are surgical and conservative management strategies in pituitary apoplexy patients. The use of both methods may lead to delayed surgery in the treatment of pituitary apoplexy. The aim of this study was to evaluate the surgical indications and outcomes of a series of patients with pituitary apoplexy according to delay between surgery and symptom onset.

METHODS

A retrospective analysis was performed of 2711 cases with sellar pathologies treated with endoscopic transsphenoidal surgery in a single centre. Inclusion criteria were histopathological confirmation of haemorrhage or necrosis, acute onset and at least one of the following: symptoms of endocrine dysfunction; visual impairment; ophtalmoplegia; headache; or altered consciousness. Patients were divided into three groups based on the number of days from initial symptoms to surgery: early (1-7 day), delayed (8-21 days) and late (>21 day). The indication for and outcome of surgery was reviewed according to symptoms and timing of surgery.

RESULTS

Ninety-one patients with pituitary apoplexy underwent surgery. The median time from ictus until surgery was 16 days (1-120 days). Headache was the most common presenting symptom. Visual impairment and ophtalmoplegia were found in 26.4% and 23.1% of patients, respectively. Surgical intervention was successful in treatment of headache in 82 (97,6%) patients. In patients in the early or delayed groups a significant improvement was found between pre- and post-operative headache, ocular palsy, visual impairment, and hormone deficiencies. Patients in the late group also had a significant improvement in headache and visual symptoms after surgery.

CONCLUSION

Surgery was sufficient in headache, endocrine, and neuro-ophthalmic outcomes at first 21 days (early and delayed groups). Beyond 21 days (late group), surgery was not effective on recovery of pituitary function.

Endoscopic approach for giant pituitary adenoma: clinical outcomes of 205 patients and comparison of two proposed classification systems for preoperative prediction of extent of resection

OBJECTIVE

Giant pituitary adenoma is considered a challenging pathology for surgery owing to its complications and low resection rate. In this study, the authors present their experience of using the endoscopic endonasal approach to treat patients with giant pituitary adenoma, and they aimed to develop a classification system for prediction of extent of resection.

METHODS

The institutional medical records of patients diagnosed with giant pituitary adenoma who underwent endoscopic endonasal transsphenoidal surgery between August 1997 and December 2019 were retrospectively reviewed. Surgical and clinical outcomes were evaluated in detail. The effects of tumor characteristics on extent of resection were analyzed. The findings were used to develop two classification systems that could preoperatively predict extent of resection. Morphological score was based on tumor characteristics, and landmark-based classification was defined according to surgical zones based on neurovascular landmarks. The effects of change in surgical strategy, which aimed to maximize tumor resection and capsule dissection, on rates of resection and complications were evaluated before and after 2017.

RESULTS

This study included 205 patients, with a mean patient age of 46.95 years and mean preoperative tumor diameter of 46.56 mm. Gross-total resection (GTR) was achieved in 35.12% of patients, near-total resection (NTR) in 39.51%, and subtotal resection (STR) in 25.36%. Extent of resection differed significantly between the grades and zones of the classification systems (p < 0.001 for both). Among patients with grade 3 tumor, 75.75% of patients achieved STR, 21.21% achieved NTR, and 3.03% achieved GTR. Among patients with zone 3 tumor, 65.75% achieved STR, 32.87% achieved NTR, and 1.36% achieved GTR. Both grade 3 and zone 3 indicated limited extent of resection. The mean (range) follow-up duration was 50.16 (9-247) months. Postoperative recovery of at least one hormone axis was seen in 15.24% of patients with pituitary deficiency, and development of new hormonal deficiency was observed in 22.43% of patients. Complications included permanent diabetes insipidus (7.80%), cerebrospinal fluid leakage (3.90%), postoperative apoplexy (3.90%), meningitis (3.41%), and epistaxis (3.41%). The surgical mortality rate was 1.46%. Among 85 patients treated before 2017, 27.05% of patients achieved GTR, 37.64% achieved NTR, and 35.29% achieved STR; among 120 patients treated after 2017, 40.83% achieved GTR, 40.83% achieved NTR, and 18.33% achieved STR. Seven patients in the pre-2017 cohort had postoperative apoplexy versus only 1 patient in the post-2017 cohort. There were no statistically significant differences between the two periods in terms of the incidence rates of other complications.

CONCLUSIONS

Capsule dissection and GTR are valuable for preventing serious complications and reducing recurrence of giant adenoma. Treatment of giant pituitary adenoma may be better managed with the help of a classification system that provides information about extent of resection that can be achieved with an endoscopic approach.

Operative nuances and surgical limits of the endoscopic approach to clival chordomas and chondrosarcomas: A single-center experience of 72 patients

OBJECTIVE

Gross total resection (GTR) is the mainstay therapy for chordomas and chondrosarcomas to have the best prognosis. The aims of this study were to specify the limits of EEA, emphasize the need for additional combined approaches for tumors beyond these limitations for high resection rates, discuss the prognostic factors and operative nuances that affect GTR, and present the causes and characteristics of early and late recurrences.

METHODS

We retrospectively analyzed the endoscopic endonasal surgeries in the Pituitary Research Center and Neurosurgery Department of the Kocaeli University Faculty of Medicine, Turkey between January 2004 and December 2019. We retrospectively reviewed the medical data, radiological images, and surgical videos of patients, and 72 patients with chordoma and chondrosarcoma were included in the study.

RESULTS

Based on pathology reports, 72 patients (seven pediatric) were identified, to whom 91 endoscopic operations were performed. We determined the surgical limitations for each clival segment as superior, middle, and inferior. Then, we divided these into three subgroups according to whether the tumor shows dural invasion (extradural chordoma, large extradural - minimal intradural component, and minimal extradural - large intradural component). The tumors of 19 (26.4%), 25 (26.4%), and nine (12.5%) patients originated from the superior, middle, and inferior clivus, respectively. Nineteen (26.4%) patients had panclival involvement. GTR was performed in 47 (65.3%) the patients. The GTR rate in patients with panclival tumors was 47.3% (9/19). The experience, lateralization, dural involvement, and origin of the clivus affecting GTR were analyzed. Extradural - intradural extensions were verified as negative predictor factors for GTR, whereas tumors located in the superior (OR: 16.710, p=0.030) and middle (OR: 11.154, p=0.023) segments were positive predictive factors for GTR.

CONCLUSION

An increasing experience in endoscopic surgery significantly increases the GTR rates by widening the surgical limitations. Due to dense bone infiltration and adhesion to critical neurovascular structures, recurrence rates are high despite performing GTR. Although surgery and adjuvant treatments improve the 5-year survival of patients, the mortality rates remain high. Therefore, surgery of these tumors should be performed by experienced centers. In addition to surgical and adjuvant therapies, targeted molecular and translational biological therapies are also needed for chordomas and chondrosarcomas in the future.

Endoscopic Transorbital Approach to the Cavernous Sinus Lateral Compartment (Anatomical Cadaver Study)

INTRODUCTION

Although experience with cavernous sinus (CS) surgery has increased over the years, it is still difficult to access the anteroinferior and lateral compartment with endoscopic endonasal transsphenoidal surgery (EETS) and resection rate of tumors which invaded the lateral compartment is low. This study aimed to determine whether the ETO approach could be an alternative and a safer route to access the CS lateral compartment.

MATERIALS AND METHODS

ETO technique was studied on 3 cadavers and 6 CS of these cadavers. Endoscopic dissection was visualized with a 0-degree angle endoscope and recorded with fiberoptic cable, light source and camera system and digital video recording system.

RESULTS

Superior orbital fissure (SOF), optic canal (OC), anterior ethmoidal artery (AEA) and posterior ethmoidal artery (PEA) foramens were visualized with periorbital dissection. Anterior wall of CS was reached after drilling the optic strut (OS). When the wall was opened, CS lateral and anteroinferior compartments were visualized. Internal carotid artery (ICA) were visualized from proximal ring to the last 2 cm of paraclival carotid artery. Cranial nerves (CNs) within the CS and the course of the interclinoid ligament were revealed.

CONCLUSION

The transorbital endoscopic method is an alternative approach to other techniques for accessing the lateral and anteroinferior compartments of CS. The advantages, disadvantages and limitations of the technique have been determined.

Anatomic and histologic features of diaphragma sellae that effects the suprasellar extension

This study aimed to determine the anatomical and histological features of diaphragma sellae that affect the suprasellar extension of intrasellar tumours. Twenty-four fresh adult cadavers were dissected for the study. Diaphragma sellae and pituitary capsules with sellar structures were resected. The diaphragma sellae was anatomically reviewed in detail. Immunohistochemical staining was performed for collagen types I, II, III, and IV. We examined the suprasellar growth of 13 sellar tumours extending superiorly through the diaphragma sellae by performing a series of 2704 endoscopic transnasal operations to analyse the anatomic and histologic results of the study. The diameter of the foramen of diaphragma sellae varied between specimens. Of 24 specimens, the diaphragma sellae in five (21%) had a tight-type foramen and those in 19 (79%) were more spacious. An increased expression of collagen types I and IV was observed in the pituitary capsule and the diaphragma sellae. In this clinical series, we observed that all types of sellar tumours could expand through the foramen. We observed radiologically and intraoperatively that the diaphragma sellae was displaced laterally and formed a dome in two cases with an adenoma extending to the suprasellar area. Two types of suprasellar extension through the diaphragma sellae are possible: 1) The collagen structure of diaphragma sellae can be destroyed by invasive tumours; 2) The morphology of the foramen of the diaphragma sellae facilitates suprasellar tumoural extension. All sellar tumours, including non-invasive cystic tumours, may invade the suprasellar area by expanding through the foramen of the diaphragma sellae.

Primary pituitary abscess case series and a review of the literature

OBJECTIVE

Pituitary abscess is a rare condition, with approximately 300 cases reported in the literature. Primary pituitary abscess, the most common type, occurs in previously healthy normal glands. Secondary pituitary abscess is secondary to pre-existing lesions in the pituitary region, such as pituitary adenoma, Rathke's cleft cysts, or craniopharyngioma and infections.

MATERIAL AND METHODS

A total of 2281 patients underwent pituitary surgery via endoscopic transsphenoidal approach in Kocaeli University Pituitary Gland Research Center between 1997 and 2018. Among this cohort 9 patients (4 female and 5 male) were diagnosed with primary pituitary abscess based on both intraoperative findings and postoperative histopathological evidence.

RESULTS

Primary pituitary abscess incidence was obtained 0.39% in our center. Mean age of the patients was 50 years old. There was no history of pituitary surgery, radiotherapy and infection diseases in our patients. Visual symptoms were prominent in two patients, hypopituitarism was found in 5 out of the 9 patients. All patients have typical pituitary lesion on pituitary magnetic resonance imaging. Staphylococcus species were the most commonly isolated organisms in the culture. A few weeks of antibiotic therapy were administered after surgery.

CONCLUSION

Presentation of fever, headache, diabetes insipidus, hypopituitarism and a sellar cystic mass with an enhanced rim after gadolinium contrast on pituitary magnetic resonance imaging may be suggestive of a pituitary abscess. Transsphenoidal endoscopic surgery, proper antibiotics and appropriate hormone replacement therapy when necessary are the keys of pituitary abscess treatment.

The Utility of Preoperative ACTH/Cortisol Ratio for the Diagnosis and Prognosis of Cushing's Disease

Purpose:

Cushing's syndrome (CS) is a rare disease having diagnostic difficulties. Many diagnostic tests have been defined but none of these are diagnostic alone. Determination of the cause is another problem which sometimes requires more sophisticated and invasive procedures. Therefore, we aimed to evaluate the utility of pretreatment plasma adrenocorticotropic hormone (ACTH)/cortisol ratios in patients with confirmed endogenous CS for the diagnosis and differential diagnosis of CS.

Materials and Methods:

This retrospective evaluation included 145 patients with the diagnosis of CS, 119 patients with Cushing's disease (CD), and 26 patients with ACTH-independent CS (AICS), in a university hospital. Furthermore, 114 individuals in whom CS diagnosis was excluded with at least one negative screening test were enrolled to the study as control group. The clinical, laboratory, imaging, postsurgical pathologic records and also clinical follow-up data of all patients were evaluated.

Results:

The median basal ACTH/cortisol ratio of the patients with CD was significantly higher than AICS and controls. A cutoff ACTH/cortisol ratio >2.5 was found to be diagnostic for CD with 82% specificity and 63% sensitivity. Among CD group, patients with recurrent disease had higher preoperative ACTH levels and ACTH/cortisol ratio than patients with sustained remission. Furthermore, these patients had more invasive, atypical, and larger tumors.

Conclusion:

An ACTH/cortisol ratio >2.5 would be beneficial to diagnose CD together with other diagnostic tests. It is a simple test with no additional cost. Higher ratios might be related with larger, invasive, and atypical adenoma and also might be helpful to predict recurrence.

The Predictor Role of the Aqueduct Cerebrospinal Fluid Flow on Endoscopic Third Ventriculostomy: Explication on Assumption Physical Model

AIM

To evaluate the cerebrospinal fluid (CSF) flow dynamics in the aqueductus sylvii of patients with obstructive hydrocephalus who underwent endoscopic third ventriculostomy (ETV) and to predict ventriculostomy patency via aqueduct flow measurements.

MATERIAL AND METHODS

Twenty-four patients with obstructive hydrocephalus caused by primary aqueduct stenosis who underwent ETV were included in the study. All the patients underwent conventional and cine magnetic resonance imaging before and after treatment. The flow of CSF in the aqueduct of Sylvius and prepontine cistern was assessed, and the diameter of the third ventricle was also measured. Increase in the aqueduct flow velocity after a successful ETV was supported by the assumption physical model that highlights a possible mechanism that explains the clinical findings.

RESULTS

The flow pattern and velocity in the prepontine cistern and aqueduct were normal in 17 out of 24 patients who responded to ETV clinically. However, seven patients who did not respond to ETV had an abnormal flow pattern in both the prepontine cistern and aqueduct.

CONCLUSION

The flow pattern in the aqueduct was normalised and velocity was increased compared with those of preoperative values after a successful ETV. The flow of CSF in the prepontine cistern is routinely used for ventriculostomy patency assessment. In addition, aqueduct measurements may be useful in predicting ventriculostomy patency. The physical model provides valuable insights on a possible mechanism that affected the experimental data.

A Haptic Guided Robotic System for Endoscope Positioning and Holding

AIM

To determine the feasibility, advantages, and disadvantages of using a robot for holding and maneuvering the endoscope in transnasal transsphenoidal surgery.

MATERIAL AND METHODS

The system used in this study was a Stewart Platform based robotic system that was developed by Kocaeli University Department of Mechatronics Engineering for positioning and holding of endoscope. After the first use on an artificial head model, the system was used on six fresh postmortem bodies that were provided by the Morgue Specialization Department of the Forensic Medicine Institute (Istanbul, Turkey).

RESULTS

The setup required for robotic system was easy, the time for registration procedure and setup of the robot takes 15 minutes. The resistance was felt on haptic arm in case of contact or friction with adjacent tissues. The adaptation process was shorter with the mouse to manipulate the endoscope. The endoscopic transsphenoidal approach was achieved with the robotic system. The endoscope was guided to the sphenoid ostium with the help of the robotic arm.

CONCLUSION

This robotic system can be used in endoscopic transsphenoidal surgery as an endoscope positioner and holder. The robot is able to change the position easily with the help of an assistant and prevents tremor, and provides a better field of vision for work.

Detection and Evaluation of Intracranial Aneurysms with 3D-CT Angiography and Compatibility of Simulation View with Surgical Observation

AIM

The aim of this study was to report our experience with a 64-channel computerized tomography (CT) scanner as the primary choice on the detection of intracranial aneurysms. Comparison of intracranial aneurysms with the simulated images obtained via three-dimensional computed tomography angiography (3D-CTA) in pterional approach was also aimed.

MATERIAL AND METHODS

Among 288 consecutive patients who had intracranial aneurysms detected on 64-slice CTA, a total of 337 aneurysms were detected. CTA simulation images and intraoperative images were compared with regards to size, shape, and orientation.

RESULTS

In one of the 22 CTA-negative cases, one aneurysm was detected in DSA and an additional aneurysm was detected in a patient operated with CTA. Aneurysm size, shape and direction were error free except a few cases. However, CTA was found to be insufficient to show particularly perforating arteries that were smaller than 2 mm in size.

CONCLUSION

As a fast and noninvasive technique, CTA can be used as an initial examination in subarachnoid hemorrhage. Keeping the fact that there can be insufficiency in showing particularly small aneurysms in mind, DSA should be performed on CTA-negative cases and required cases.

Aromatase enzyme expression in acromegaly and its possible relationship with disease prognosis

The purpose of this study was to evaluate aromatase enzyme expression in growth hormone (GH) secreting adenomas and comparison with prolactinomas, nonfunctional adenomas, and normal pituitary tissues. Also the impact of its expression on clinical and prognostic features was evaluated. 38 acromegaly, 26 prolactinoma, and 31 nonfunctional pituitary adenoma and 11 normal pituitary gland samples from autopsies were included. Aromatase and estrogen receptor-alpha (ERα) were evaluated by Immunohistochemical method; demographic, pre- and postoperative features of the patients were noted. Aromatase was expressed in varying degrees in all cases in study including controls. Aromatase expression in patients with acromegaly was significantly higher than patients with prolactinoma, nonfunctional adenoma, and controls (p = 0.04, p = 0.01 and p < 0.001, respectively). Taken together two functional adenoma groups, prolactinoma and acromegaly, aromatase expression was negatively correlated with ER-alpha (p = 0.02, r = -0.34). Also, Ki-67 immunohistochemical results were negatively correlated with aromatase expression (p = 0.03, r = -0.27) while positively correlated with ER expression (p < 0.01). Consistent with the growing evidence about testosterone effect on pituitary functions, aromatase expression was found to be higher in GH-secreting pituitary adenoma. Aromatase was expressed in all pituitary tissues including autopsy samples; however, it was highest in patients with acromegaly. In patients with acromegaly and prolactinoma, aromatase expression was negatively correlated with Ki-67 score, and also it was higher in patients with complete postoperative remission than without remission. Therefore, aromatase expression may be a good prognostic marker predominantly in acromegaly.

Endoscopic distinction between capsule and pseudocapsule of pituitary adenomas

BACKGROUND

Pseudocapsules were first identified in pituitary adenoma surgery in 1936. Since then, the distinction between pituitary capsules and pseudocapsules has been unclear, and the definitions of these entities have varied. In this study, pituitary capsules and extracapsular dissection were examined retrospectively, intra- and extrapseudocapsular resection was evaluated, and dissection of the pituitary adenoma and pseudocapsule was examined prospectively.

METHODS

Between January 2009 and May 2012, endoscopic transsphenoidal pituitary surgery was performed on 224 patients in the Department of Neurosurgery, Kocaeli University Faculty of Medicine, Turkey. Data for 174 patients were analyzed retrospectively between January 2009 and December 2011, and 50 patients treated between December 2011 and May 2012 were included in a prospective study.

RESULTS

In the retrospective phase of the study, capsules were examined in 21 of the 174 patients on whom extracapsular resection had been performed. In the 50 cases treated between December 2011 and May 2012, dissection of the pituitary capsule, adenohypophysis, and pseudocapsule was performed. In 30 patients in the prospective phase of the study, pseudocapsules were identified during intraoperative endoscopic observation. Remission was achieved in 28 of 33 functioning adenomas in the prospective study. The mean follow-up period in this group was 13 months.

CONCLUSION

The endoscopic and histopathological evidence provided in this study demonstrates that the pituitary capsule and pseudocapsule are distinct structures. In addition, it is also shown that extracapsular dissection can be performed in functioning adenomas that invade the suprasellar region. Significantly higher rates of total resection and higher remission rates were observed in cases where extra- and intrapseudocapsular dissection was required.

Endoscopic approach to cavernous sinus aneurysm

Aneurysms protruding into sellae may mimic pituitary tumors by compressing adjacent cranial nerves. Carotid-Cavernous aneurysms are rarely associated with mortality, and surgical intervention is recommended especially for neuro-ophthalmologic progression. In this report we presented a 51-year-old woman who had severe headache and neuro-ophthalmologic signs with the initial diagnosis of pituitary apoplexy on MRI (Magnetic Resonanse Imaging). However preoperative CTA (Computed Tomography Angiography) revealed a carotid cavernous aneurysm protruding into sellae. The patient underwent endovascular intervention and endoscopic transphenoidal approach for the removal of the hematoma compressing the cranial nerves. The patient's neuro-ophthalmologic symptoms were improved during the follow-up, which may be related due to rapid evacuation of the hematoma.

Endoscopic transphenoidal approach for fibrous dysplasia of clivus, tuberculum sellae and sphenoid sinus; report of three cases

AIM

Fibrous dysplasia is a benign disease in which medullary bone is replaced by fibro-osseous tissue, and causes distortion and overgrowth of the involved bone and represents about 3% of all bone tumors. There is variability in the manifestation of Fibrous Dysplasia lesions with imaging techniques due to their proportional variations of fibrous to osseous tissue. Radiological differential diagnoses include meningioma, chordoma on MRI and Paget disease on CT imagings.

MATERIAL AND METHODS

We report three cases of monostotic fibrous dysplasia, affecting clivus, tuberculum sellae, and sphenoid sinus through the pterygopalatine fossa. We performed pure endoscopic transphenoidal approach for those three cases with the guide of neuronavigation. Extended approach was used via binostril for fibrous dysplasia of clivus and Tuberculum sellae.

RESULTS

Radiologic report revealed chordoma and meningioma for the two cases and fibrous dysplasia for the last case. Total resection of tuberculum sellae, subtotal resection of clivus and partial resection of sphenoid sinus lesions were performed. Pathology diagnosis were fibrous dysplasia in all three patients.

CONCLUSION

Histopathological sampling provided by surgical approach should be obtained to establish the final diagnosis. Endoscopic approaches are convenient for skull base lesions even for biopsy or curative resections providing panoramic view and avoid brain retraction.

Neuroprotective effect of memantine on hippocampal neurons in infantile rat hydrocephalus

AIM

The effect of memantine administration on hippocampal neurons of the infantile rats with kaolin induced hydrocephalus was investigated.

MATERIAL AND METHODS

Hydrocephalus was induced by injecting kaolin into the cisterna magna of 3-weeks old Sprague-Dawley rat pups. One group received a single daily dose of 20mg/kg memantine i.p. following hydrocephalus induction for a period of two weeks. By the end of the two-week period, animals were radiologically evaluated by magnetic resonance imaging and then sacrificed to get their cerebrums removed. Both immunohistochemical analysis of nitric oxide synthase activity and quantification of spared neurons in CA1, CA2 and CA3 regions of hippocampus were performed.

RESULTS

In hydrocephalus-induced rats considerable neuronal loss associated with significantly increased nitric oxide synthase immunoreactivity were determined in all hippocampal regions. However, memantine treated rats showed significantly higher number of spared neuron counts and reduced nitric oxide synthase immunoreactivity in CA1 and CA2 regions compared with the non-treated rats.

CONCLUSION

The findings of the study show that hippocampal neurons may constitute important targets for injury secondary to hydrocephalic process in experimental infantile hydrocephalus. Early anti-excitotoxic treatment with memantine seems to have a neuroprotective effect especially in the CA1 and CA2 subunits of the hippocampus.

Immunohistochemical analysis of TIMP-2 and collagen types I and IV in experimental spinal cord ischemia-reperfusion injury in rats

BACKGROUND

Thoracic and thoracoabdominal aortic intervention carries a significant risk of spinal cord ischemia. The pathophysiologic mechanisms that cause hypoxic/ischemic injury to the spinal cord have not been totally explained. In normal spinal cord, neurons and glial cells do not express type IV collagen. Type IV collagen produced by reactive astrocytes is reported to participate in glial scar formation. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of the matrix metalloproteinases (MMPs). TIMP-2 binds strongly with MMP-2, facilitating activation by membrane-type MMP. Imbalance between TIMPs and MMPs can lead to excessive degradation of matrix components. Type IV collagen involved in the blood-brain barrier disruption and glial scar formation, TIMP-2 influences MMP-2 that controls degradation of collagen I and IV.

OBJECTIVE

To examine the immunohistochemical analysis of TIMP-2 and collagen types I-IV in experimental spinal cord ischemia-reperfusion in rats.

METHODS

Thirty-two male Wistar rats weighing 250-300 g were divided into four groups: group S: sham group (n = 8); group 0P: 30-minute occlusion without perfusion (n = 8); group 3P: 30-minute occlusion and 3-hour perfusion (n = 8); and group 24P: 30-minute occlusion and 24-hour perfusion (n = 8). Infrarenal aorta was cross-clamped at two sites by using two aneurysm clips for 30 minutes. Reperfusion was provided after removal of the clips. Lumbar spinal cord segments were removed for immunohistochemical analysis.

RESULTS

TIMP-2 and collagen staining in 3-hour perfused (3P) group were nearly the same with sham group (S). TIMP-2 and collagen staining increased in the 24-hour perfused group.

CONCLUSION

Alterations in collagen levels may relate to the biphasic breakdown of the blood-brain barrier and collagen staining in new cell types with relation to glial scar formation. Our results demonstrate that 3-hour perfusion after occlusion in hypoxic/ischemic spinal cord injury seems to be the critical reversible period.

Fluorescein sodium-guided surgery in glioblastoma multiforme: a prospective evaluation

We have evaluated the influence of fluorescein-guided resection on gross total resection (GTR) and survival in a series of patients with GBM. Group 1 consisted of 47 patients given fluorescein and group 2 comprised 33 patients, on whom fluorescein was not used. Median survival time was 43.9 weeks in the patients given fluorescein and was 41.8 weeks in the non-fluorescein group. There was no statistically significant difference in survival between the two groups. However, the extent of resection had a powerful influence on the median survival time. Survival was 34.3 weeks after partial resection and 46.5 after GTR. Our data shows that the use of fluorescein injection is a simple procedure, which allows a significant increase in the number of patients having GTR (83 vs. 55%). Our findings are similar to a recently published multicentre Phase III randomized trial in which 5-aminolevulinic acid was used to facilitate resection of malignant glioma.

Chiari 1 malformation with syringomyelia: correlation of phase-contrast cine MR imaging and outcome

AIM

This study was designed to determine the hemodynamics of cerebrospinal fluid flow in syringomyelia patients associated with Chiari I malformation using phase-contrast velocity-encoded-cine MRI and also to find out whether treatment outcomes may be predicted by these flow measurements.

MATERIAL AND METHODS

Eighteen consecutive symptomatic patients with syringomyelia associated with Chiari 1 malformation were included. The PC VEC MRI was performed at the level of foramen magnum and syrinx cavity both preoperatively and 6 months postoperatively. Following surgery, the modified Asgari score was calculated, and the association between CSF flow pattern and clinical outcome was assessed.

RESULTS

Evaluation of clinical symptoms at postoperative 6th month revealed improvement in 11 (61%) patients and stabilization in 5 (28%) patients whereas results were poor in 2 (11%) patients. Preoperative cine MRI flow studies showed a heterogeneous pattern at the foramen magnum level in all of the patients. Postoperative cine MR flow studies demonstrated the change from heterogeneous pattern to sinusoidal pattern in 11 patients and a decrease in heterogeneity in 7 patients.

CONCLUSION

Our results indicate that CSF flow measurements using PC VEC MRI can give important information regarding the prognosis and follow-up of the patients with Chiari I malformation.

The learning curve in endoscopic pituitary surgery and our experience

Experience is the important point in reduction of the complications and in the effectiveness of the surgical procedure in pituitary surgery. Endoscopic pituitary surgery differs from microscopic surgery, since it requires a steep learning curve for endoscopic skills. In this article, we evaluate our learning curve in two groups, as early and late experience. Purely endoscopic transsphenoidal operations were performed on 78 patients, which were retrospectively reviewed and grouped as early and late experience groups. We used the purely endoscopic endonasal approach to the sella that was performed via an anterior sphenoidotomy, without the use of a transsphenoidal retractor. All patients with adenomas were evaluated considering operation time, endocrinology, ophthalmology, total removal and, especially, modifications of standard technique. On the basis of the experience gained with the use of the endoscope in transphenoidal surgery over the years, modifications can be performed on the different phases of the endoscopic approach. Reviewing our cases in two groups of period due to our experience showed that the effectiveness of endoscopic surgery increases and operation time decreases. In our study, we identified a learning curve in endoscopic pituitary surgery.